PANC-1 Cells Research Articles

Abstract 1458: Anti tumoral role of PDX1 on pancreatic ductal adenocarcinoma aggressiveness

Abstract Pancreatic ductal adenocarcinoma (PDAC) represents a very aggressive type of pancreatic cancer (9% survival rate at 5 years). PDX1 is an important transcription factor for embryonic development of the pancreas, endocrine lineage differentiation and the maintenance of mature beta cells. Notably, in PDAC patients, the expression of PDX1 is downregulated in tumor cells compared to adjacent non-tumoral tissue. Interestingly, increasing tumor PDX1 expression has been shown to enhance the overall survival rate in PDAC patients. Therefore, our aim was to analyze the role of PDX1 on tumor aggressiveness of PDAC cells. To induce PDX1 expression, PANC1 cells were treated with BRD7552 (a PDX1 inducer) for 9 days. Overexpression of PDX1 was confirmed by Western Blot analysis and no cytotoxic effects were observed by MTT or Trypan Blue exclusion assays on treated cells compared to control. Wound healing and transwell migration assays showed a significant reduction in the migration rate compared to the control group. A higher proportion of cells in G1 phase was observed in treated cells compared to control by propidium iodide staining followed by flow cytometry assay. Furthermore, the cell confluence assay showed a significant reduction in proliferation rate in treated cells compared to control, but no differences were observed on the proportion of KI67+ and PH3+ cells by immunostaining. To assess the in ovo effects of BRD7552, treated PANC1 cells were implanted onto the chorioallantoic membrane of chick embryos and tumor growth was measured at different stages observing a significant reduction in tumor growth in PANC1 cells compared to control between days 3 and 8 post implantation. No significant differences in morphology or color were observed between treated and control implanted cells. Hematoxylin-eosin staining showed reduced invasion of treated cells into the chorioallantoic membrane compared to control. In conclusion, the overexpression of PDX1 affects cell cycle, reduces proliferation rate and inhibits migratory potential in vitro. Moreover, in an in ovo model this overexpression diminished tumor growth and invasion in PANC1 cells. In conclusion, the overexpression of PDX1 induced by BRD7552 drives pancreatic ductal adenocarcinoma to a less aggressive tumoral phenotype. Citation Format: Jimena Mosna, Federico Garde, Marcelo Stinson, Candela Pastore, Pablo Sanchis, Abel Carcagno. Anti tumoral role of PDX1 on pancreatic ductal adenocarcinoma aggressiveness [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1458.

Abstract 566: The anticancer effects of polyisoprenylated cysteinyl amide inhibitors involves interaction with the KRAS chaperone calmodulin

Abstract Pancreatic cancer is the third leading cause of cancer-related deaths with a 5-year survival rate of less than 10%. Approximately 90% of reported cases are driven by KRAS mutations. The mutant KRAS acquires its functional localization through interactions with chaperone proteins via its polybasic polyisoprenylated tail. Polyisoprenylated cysteinyl amide inhibitors (PCAIs) mimic this region possibly disrupting the polyisoprenylation-dependent interactions with chaperone proteins. Here, we determine the effect of newly developed PCAIs that were designed to be more water-soluble on cell viability, 3D spheroid invasion, spheroid degeneration and F-actin filaments on MIA PaCa-2 and PANC-1 cells. Of the seven new PCAIs analogs tested, NSL-AB-51 and NSL-AB-45 were the most potent, with EC50 values of 2.5 and 5.6 µM against MIA PaCa-2, and 1.7 and 4.5 µM against PANC-1 cells, respectively. At 5 and 10 µM, NSL-AB-51 decreased the invasion area of 3D spheroids by 98 and 99%, respectively. MIA PaCa-2 spheroids degenerated by 61% after 72 h treatment with 10 µM NSL-AB-51. Treatment with 1.0 μM NSL-AB-51 caused cell rounding and reduction of mean cell areas by 69% and F-actin filaments by 96%. Moreover, to identify the pharmacological target of the PCAIs, NSL-AB-45 was coupled to an epoxy-activated Sepharose resin for affinity trapping of PCAIs-interacting proteins. Affinity-analysis of supernatants and detergent membrane extracts from MIA PaCa-2 and PANC-1 cells revealed single Coomassie band of about 17 kDa that was identified as calmodulin by western blotting analysis. The calmodulin-PCAIs affinity interaction was found to be strongest in the presence of calcium and weakest in the presence of EDTA. These findings reveal that calmodulin is the likely target of PCAIs. Since calmodulin is the chaperone protein responsible for KRAS trafficking and localization to the inner surface of the plasma membrane, this finding strongly suggests, at least in part, an anticancer role for the PCAIs that involve disruption of KRAS functions. Citation Format: Kweku Ofosu-Asante, Jassy Mary Lazarte, Amarender Burra, Nazarius S. Lamango. The anticancer effects of polyisoprenylated cysteinyl amide inhibitors involves interaction with the KRAS chaperone calmodulin [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 566.

Abstract 4495: Structure-based screening for potential ROR1 inhibitors and their potential as antitumor agents in pancreatic cancer cells

Abstract Background: The identification of novel compounds that specifically target cancer cells while sparing normal tissues is crucial. The orphan tyrosine kinase-like receptor 1 (ROR1) is one such target expressed exclusively in various human malignancies, including pancreatic cancer, but not in normal adult tissues. Inhibiting ROR1 signaling shows promise in halting pancreatic cancer cell proliferation and invasion. In this study, lead compounds CSF1R-IN-1 and MCULE-8715589337 were found as potential inhibitors of the ROR1 and were further evaluated for its potential effect on pancreatic cancer cell viability. Method: We curated a compound library of 6 million from PubChem, 2 million lead-like compounds from ZINC15, and 2 million compounds from diverse vendors. Employing Glide’s HTVS followed by XP, we refined the selection based on docking scores lower than the reference molecule, Ponatinib. Compounds were shortlisted by pre-simulation MMGBSA calculations with Schrödinger Prime MM-GBSA module, focusing on compounds with energies below -100 kcal/mol. Then we performed MD simulation for 100ns. Post-simulation MMGBSA on the last 1 ns of simulation assessed change in ligands’ binding energies. The selected leads underwent further validation utilizing two pancreatic cancer cell lines, MiaPaCa-2 and PANC-1. Half-maximal inhibitory concentration (IC50) was assessed using MTS cell viability assay. Result: Comparing pre- and post-simulation MMGBSA energies, the reference compound showed increased, while CSF1R-IN-1 and MCULE-8715589337 exhibited decreased energies. The reference ligand's RMSD showed stability with fluctuations of 3 to 3.5 Å, whereas CSF1R-IN-1 and MCULE-8715589337 had stable and lower RMSD values (approximately 3 Å and 2.4 Å). Test compounds, CSF1R-IN-1 and MCULE-8715589337 showed better molecular interactions with ROR1 compared to reference. The reference compound formed hydrogen bonds with ILE555 and ASP633, along with pi-pi stacking with PHE552. CSF1R-IN-1 forms a hydrogen bond with ILE555 and ASP633, pi-pi stacking with PHE552, and interaction with SER632 through a water bridge. Additionally, compound MCULE-8715589337 forms hydrogen bonds with ASP633, SER632, LYS506, and GLU523. CSF1R-IN-1 notably inhibited proliferation in MiaPaCa-2 cells (IC50: 1.29 μM) while no efficacy in PANC-1 cells (IC50: 78.41 μM). MCULE-8715589337 showed relatively similar IC50 values of 39.06 μM and 37.73 μM in MiaPaCa-2 and PANC-1 cells, respectively. Conclusion: The reduction in MMGBSA energies, low RMSD values, and a higher number of interactions highlight the better characteristics of both compounds compared to the reference. Our findings show CSF1R-IN-1 and MCULE-8715589337 have efficacy in pancreatic cancer cells, but further studies are required to validate and to understand the mechanism of action. Citation Format: Indrakant Kumar Singh, Shradheya RR Gupta, Pooja Mittal, Shivani Soni, Jae Ho Lo, Francesca Battaglin, Yan Yang, Lesly Torres-Gonzalez, Sandra Algaze, Priya Jayachandran, Karam Ashouri, Alexandra Wong, Wu Zhang, Joshua Millstein, Heinz Josef Lenz. Structure-based screening for potential ROR1 inhibitors and their potential as antitumor agents in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4495.

Abstract 7495: Validation of microfluidic isolation of circulating pancreatic tumor cells from blood

Abstract Background. Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and is the fourth leading cause of cancer-related deaths in the US. PDAC is diagnosed in the late stages, which limits treatment options and yields poor clinical outcomes. Recurrence is a significant issue for patients undergoing surgery for PDAC. Circulating tumor cells (CTCs) are thought to be a potential mediator of recurrence, facilitating the formation of secondary tumor sites after surgery. Thus, there is a need to isolate CTCs to improve understanding of disease recurrence, to ultimately improve outcomes. Herein, we aim to validate our inertial microfluidic (iMF) system for isolating pancreatic CTCs from blood. We also benchmark our iMF system to a commercially available immunomagnetic negative selection system, EasySep™, and quantify target cell recovery and cell enrichment. Methods. Our iMF system employs the differential cell sizes of CTCs from blood cells and inertial migration of such cells in a straight microchannel (150 µm × 50 µm × 24 mm) to enrich CTCs from blood. The iMF system sample flow rate used is 100 µL/min, with a 200 µL/min PBS buffer flow rate. The EasySep™ Direct Human CTC Enrichment kit targets CD2, CD14, CD16, CD19, CD45, CD61, CD66b, and Glycophorin to remove blood cells from the sample using magnetic particles, thereby separating them from CTCs. We spiked low cell concentrations of 50, 100, and 500 Hoechst-stained pancreatic carcinoma cells, PANC1, in 1 mL of healthy blood then captured using either EasySep™ or iMF. Cell enumeration was performed after centrifugation or Cytospin. Results. PANC1 cells and WBCs have average sizes of 18 µm and 8.4 µm, respectively. We characterized our iMF device to capture cells ≥ 12 µm, which yields capture of most PANC1 cells. Indeed, our iMF system achieved 82.8±19.2%, 72.5±16.3%, and 59.3±3.8% recovery for 50, 100, and 500 cell-spikes in lysed blood, respectively. For the same 50, 100, and 500 cell-spikes, the total iMF CTC yields after Cytospin were 46.3±11.8, 44.3±9.1, and 32.7±2.1%, while the total CTC yields from EasySep™ were 4.6±3, 5.3±2.1, 8.3±1%, respectively. When we processed whole blood directly, EasySep™ had lower cell recovery, 3.8±0.2, 4.6±1, and 3.3±0.4%, respectively. Our system also demonstrated 8 × higher target cell enrichment compared to EasySep™. Blood lysis before iMF separation did not drastically affect the recovery of target cells. Conclusions. We determined that our system has improved performance over the commercial isolation system, EasySep™, thereby validating the effectiveness of microfluidic isolation for PDAC. In future studies, we can then use our iMF system in CTC isolation from routine blood draws from PDAC patients undergoing surgical resection. We may then isolate real patient samples and study relevant phenotypes of PDAC CTCs which may therefore be used for identifying certain mechanisms of PDAC progression. Citation Format: Celine Macaraniag, Ifra Khan, Jian Zhou, Pier Cristoforo Giulianotti, Alain Borgeat, Gina Votta-Velis, Ian Papautsky. Validation of microfluidic isolation of circulating pancreatic tumor cells from blood [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7495.

Abstract 1825: Synthesis and biological evaluation of novel 5-FU analogs against pancreatic cancer

Abstract Purpose: 5-Fluorouracil (5-FU) is one of the standard chemotherapy drugs used to treat pancreatic cancer. However, treatment only extends survival modestly, and disease recurrence is typical due to systemic instability, drug resistance, severe adverse effects, and limited benefits in patients with locally advanced tumors. These shortcomings have necessitated new strategies to develop safer and more effective anticancer agents. The study’s objective was to synthesize, characterize, and evaluate the cytotoxic effects of novel 5-FU analogs in pancreatic cancer cells. Methods: The analogs, XYZ-I-71 and XYZ-I-73, were synthesized by introducing a tetrahydrofuran ring on 5-fluorocytosine (a precursor of 5-FU) and conjugation with octanoyl chloride and lauroyl chloride, respectively. They were characterized by NMR, HPLC, micro-elemental analysis, and mass spectrometry. Cytotoxicity and cell migration studies were performed to determine the effectiveness of the analogs against MiaPaCa-2, PANC-1, and BxPC-3 pancreatic cancer cells. PARP apoptosis study was conducted in MiaPaca-2 cells using the analogs and 5-FU. The metabolic stability of analogs was determined by using human liver microsomes and quantified by HPLC. Results: Analysis of the 1H-NMR spectra displayed amide bonds at 7.80 ppm and 7.73 ppm, confirming the conjugation of octanoyl and lauroyl chloride to 5-fluorocutosine, respectively. The purity of both analogs was 99.6%. We found that the XYZ-I-73 (IC50 3.6 ± 0.4μM) analog was most effective against MiaPaCa-2 cells compared to XYZ-I-71(IC50 12.3±1.7μM), GemHCl (IC50 24.2 ± 1.3 μM), Irinotecan (IC50 10.1 ± 1.5 μM) and 5-FU (IC50 13.2 ± 1.1 μM). For PANC-1 cell growth inhibition, XYZ-I-73 (IC50 3.9 ± 0.5) was again observed as the most effective agent compared to XYZ-I-71(IC50 8.7±0.9 μM), GemHCl (IC50 10.07±0.9), 5-FU (IC50 20.43±1.2) and Irinotecan (IC50 11.6 ±1.1). A similar pattern of XYZ-I-73 (IC50 5.9±0.7) anticancer activity against BxPC-3 cells was found to be higher than XYZ-I-71(IC50 7.7 ± 0.8), GemHCl (IC50 10.95±0.9), 5-FU (IC50 14±1.1) and Irinotecan (IC50 9.5±1.0). For 24-hour MiaPaCa-2 cell migration studies, XYZ-I-73 (5µM) analog significantly reduced migration (# of migrated cells, 168±2.9) followed by XYZ-I-71(315±2.1), Gem-HCl (762±3.1) and 5-FU (710±3.2). PARP studies demonstrated significant inhibition of PARP expression of XYZ-I-73 treated cells compared to 5-FU and XYZ-I-71. Further, BAX and p53 expressions were significantly increased in cells treated with XYZ-I-73 compared to 5-FU and XYZ-I-71. Metabolic stability studies showed that 80 ± 5.9 % of XYZ-I-71 and XYZ-I-73 remained intact after 2-hour exposure in liver microsomal solution compared to 5-FU. Conclusion: XYZ-I-73 demonstrated a remarkable cytotoxic effect and improved in vitro metabolic stability over the selected standard drugs and may have potential anticancer activity against pancreatic cancer. Citation Format: Esther Frimpong, Raviteja Bulusu, Joy Okoro, Andriana Inkoom, Nkafu Ndemazie, Sherise Rogers, Xue Zhu, Bo Han, Edward Agyare. Synthesis and biological evaluation of novel 5-FU analogs against pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1825.

Abstract 496: Insights into correlation between nanomechanical properties and cytokines expression during gold nanoparticle endocytosis

Abstract Gold nanoparticles for therapeutic interventions have become a widely popular source due to the ease in surface chemistry available for modification. Several studies undertaken focusses on the size, shape of nanoparticles as well as the signaling mechanisms and yet, knowledge regarding the alteration in membrane dynamics such as nanomechanical properties and cytokines involved during their uptake has not been studies before. To overcome the knowledge deficit, we employed atomic force microscopy and qRT-PCR techniques to acquire nanomechanical attributes and cytokines expressions respectively, in Panc-1 and AsPC-1 cell lines treated with surface modified gold nanoparticles for 1- and 24-hours’ time point. In nanomechanics paradigm, impetus was given on both linear attributes such as membrane stiffness, deformation, and adhesion as well as non-linear attributes such as drained Poisson’s ratio, diffusion coefficient and pore size. On the other hand, qRT-PCR technique yielded alterations in relative mRNA expressions of pro-tumorigenic cytokines such as CCL2, CXCL1, CXCL2, CXCL3, IL8, IL11, IL18 and TGFβ-1. Further, using Pearson’s correlation, we deduced the dependency between nanomechanical properties and cytokines expressions. We evaluated several criteria such as receptor dependent vs independent, PEGylated vs non-PEGylated and 1 hr vs 24hrs, to deduce correlations between cytokines and nanomechanical attributes. In Panc-1 cell line, we observed that PEGylation vs non-PEGylation of gold nanoparticles demonstrated most significant correlations, whereas in AsPC-1 cell line, receptor independent mechanism played a pivotal role in establishing significant correlations. For instance, D_C and P_D were highly correlated with CXCL1, CXCL2 and TGFβ-1 when non-PEGylated gold nanoparticles were up taken by Panc-1 cells. Similarly, D_C and P_D were highly correlated consistently with our cytokine panel except for TGFβ-1. In AsPC-1 cell line, deformation was significantly correlated with CCL2, CXCL2, CXCL3 and IL-8 whereas, D_C and P_D were significantly correlated with CCL2, CXCL1, CXCL3, IL-18 and TGFβ-1 in receptor independent scenario. This study demonstrated that during the uptake of gold nanoparticles, non-linear nanomechanical attributes are detrimental over linear attributes. Moreover, Surface modified gold nanoparticles induce varying levels of alteration in pro-tumorigenic cytokines. Taken together, this study boosts our insights into correlations describing cytokines regulating nanomechanical attributes in endocytosis paradigm. Citation Format: Tanmay Kulkarni, Enfeng Wang, Ramcharan Singh Angom, Debabrata Mukhopadhyay, Santanu Bhattacharya. Insights into correlation between nanomechanical properties and cytokines expression during gold nanoparticle endocytosis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 496.

Abstract 2918: Potential for a novel therapeutic target: Effects of lactate & lactylation in expression of key regulatory cancer proteins

Abstract The purpose of our study is to investigate the immunologic, metastatic, and gene regulation effects of lactate in the context of cancer in normoxic and hypoxic conditions to identify novel biomarkers and potential therapeutic targets. We aim to modify the in-vitro cancer microenvironment to show how lactate and lactylation can be exploited using existing cancer treatments. While hyperlactatemia is defined as lactate levels between 2 mmol/L and 4 mmol/L (Foucher et al 2023), tumor biopsies have demonstrated extracellular concentrations as high as 40 mM (Pérez-Tomás et al 2020). Through CTG viability assays we identified lactate concentrations that PANC1 cells can survive, which are in agreement with the in-vivo findings of Brizel et al (2001). We observed pancreatic cancer cells achieving over 50% viability for 5 days at 50 mM lactate concentrations while at 30 mM on day 5 they proliferated past their initial plating numbers. Furthermore, Brizel et al (2001) found that patients with high tumor lactate concentrations had a significantly higher incidence of metastatic relapse. Through our scratch assay, we show qualitative evidence of increased mobility and inferred migration potential of PANC1 at 7.5mM [lactate] compared to the absence of lactate. We have also observed increased migration at higher lactate concentrations for which we are pursuing quantitative measurements to evaluate significance. Migration experiments will be followed by the investigation of gene regulation (eg. mRNA seq, lactylation profile) involved in the observed increased mobility. Lactate has been shown to affect immune regulation, namely suppression of iNKT (Fu et al, 2020), macrophages (Yang et al, 2020), dendritic cell differentiation and antigen recognition/presentation (Wang et al, 2022), however not much is known about its effect on NK cells and their cytokine expression. Through NK92MI/PANC1 cocultures we show the effects of lactate concentration on the killing ability of NK cells (in the works). And plan on investigating the cytokine profile leading to the phenotypic killing differences. Lastly, via lactate-titrated incubation of PANC1 cells in normoxia we have demonstrated a positive correlation of HIF1a expression, pan-lactyllysine lactylation, and microenvironment lactate concentration. We speculate HIF1a inhibition post-lactate-sensitization may induce cancer killing and we will investigate this theory in normoxia and hypoxia using existing treatment options. Citation Format: Christos P. Costeas, Connor Purcell, Wafik S. El-Deiry. Potential for a novel therapeutic target: Effects of lactate & lactylation in expression of key regulatory cancer proteins [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2918.

Abstract 4128: Biofield therapy suppressed invasion and metastases of human pancreatic cancer

Abstract The NIH categorizes Biofield Therapy (BT) as therapeutic approaches within energy medicine that involve using the body's energy field (biofield) for therapeutic benefit. Although controversial, in some cases devices have been developed that mimic the electromagnetic fields (EMF) that are emitted from people when delivering BTs. We previously reported that BT significantly inhibited the growth of pancreatic cancer cells and liver metastasis in their relevant animal models mediated in part through modification of the cell cycle, reductions in cell voltage potentials, and down regulation of PI3K/Akt pathways. We expanded this research to examine the potential role of BT in anti-invasiveness in human pancreatic ductal adenocarcinoma (PDAC) cells and animal models. We found that PANC-1 cells treated with BT (15 min) displayed 55% less invading cells than that of untreated incubator control and sham control cells (P < 0.001). Similar results were observed in human PDAC L3.7 cells and mouse pancreatic cancer KPCY cells. These experiments were replicated 8 times for Panc-1 cells and 4 times for L3.7 cells. Additionally, migration capacity was tested using the transwell migration and scratch assays. Consistent with the result of cell invasion assays, BT treatment also led to significant reduction of migration of PANC-1 and L3.7 cells by 34% and 41%, respectively, compared to sham controls. Two additional therapists independently replicated the anti-invasiveness and anti-migratory effects of BT on these PDAC cells. This suggests the replicability of these findings across studies and therapists. In a repeated PANC-1 mouse orthotopic model, we found that only a third of BT treated mice had visible liver nodules whereas liver metastasis was observed in more than half of mice in the untreated colony control and sham control groups. Furthermore, BT treatment significantly reduced liver tumor burden by 73% compared to that of the sham control group (p < 0.05), which was similar to that observed in the previous study. Similar to the prior PANC-1 mouse model, in the current study BT treatment had only a moderate impact on the growth of primary pancreatic tumor. We assessed certain markers indicative of cell status as well as pathways associated with migration and invasion and these will be presented at the meeting. Our findings suggest that exposure to BT reduced cellular invasion and migration processes and profoundly reduced metastasis of pancreatic tumor in an animal model. This study is in part supported by Emerald Gate Charitable Trust. Citation Format: Peiying Yang, Sharmistha Chakraborty, Phuong Nguyen, Defeng Deng, Andrew Cusimano, Daoyan Wei, Lorenzo Cohen. Biofield therapy suppressed invasion and metastases of human pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4128.

Abstract 5904: Targeting NaV1.7 channels in pancreatic cancer: Implications for EF2K and P-Src/P-Fak/integrin β1 signaling pathways

Abstract Pancreatic cancer (PaCa) ranks as the fourth leading cause of cancer-related deaths in the United States and is among the top five worldwide. Its hallmark characteristics include early invasion, metastasis, resistance to chemotherapy and radiotherapy, and aggressive tumor progression. Evaluating new generation treatments with significant potential in this ongoing battle against cancer is crucial. Voltage-gated sodium channels (VGSC), long detected in various metastatic cell lines and tissue samples beyond breast, lung, and prostate cancer, are of particular interest. This study aimed to explore the therapeutic effects of inhibiting NaV1.7 and its neonatal variant, nNaV1.7, in pancreatic cancer cells. The study utilized human normal keratinocyte cell line HaCaT and pancreatic cancer cell lines PANC-1 and MiaPaCa-2. It investigated the roles and effects of adult and neonatal isoforms of the NaV1.7 channel in pancreatic cancer proliferation, invasion, and metastasis. The findings revealed significantly higher adult and neonatal NaV1.7 mRNA expressions in PANC-1 and MiaPaCa-2 cell lines compared to HaCaT cells. Specific siRNAs effectively downregulated channel mRNA and protein expressions. Notably, NaV1.7 siRNA treatments significantly inhibited cell proliferation and colony-forming capacity in PANC-1 and MiaPaCa-2 cells, without cytotoxic effects on HaCaT cells. Combining gemcitabine with specific NaV1.7 siRNAs enhanced drug efficacy in the PANC-1 cell line. Furthermore, NaV1.7 siRNAs significantly reduced cell invasion, migration, and wound healing in both cell lines. These siRNAs also induced apoptosis and G1 arrest in the cell cycle. They inhibited protein expressions involved in key signaling pathways, including P-Src/P-Fak/Integrin β1, EF2K, P-Akt, P-mTOR, PARP, Caspase-3/9, Cyclin D1/E1. This study is pioneering, as literature lacks research on the expression and function of NaV1.7 and nNaV1.7 in pancreatic cancer cells or tissue samples. In conclusion, NaV1.7 channel isoforms play a significant role in the development, progression, and metastasis of pancreatic cancer and present as a potential therapeutic target in PaCa. Citation Format: Mumin Alper Erdogan, Ayse Caner. Targeting NaV1.7 channels in pancreatic cancer: Implications for EF2K and P-Src/P-Fak/integrin β1 signaling pathways [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5904.

Abstract 3209: Antibody mediated targeted drug delivery approach for pancreatic cancer

Abstract Pancreatic ductal adenocarcinomas, originating from the epithelial cell lining of ducts, account for approximately 95% of tumors in this category, showcasing a survival rate of less than 5-7%. Unfortunately, little progress has been seen in the outcomes of patients with PDAC as tumor develops high desmoplasia and chemo-resistance to chemotherapeutic drugs, such as gemcitabine (Gem). The therapies are unable to penetrate to the fibrotic tumors leading to insufficient availability of the therapeutic drugs at the tumor site. We and others have shown that MUC13 is aberrantly expressed in pancreatic tumors but not in normal pancreas, which makes MUC13 as an excellent protein for specifically targeting pancreatic tumors. Herein, we demonstrate a unique ability of our in-house generated mouse and humanized monoclonal antibody of MUC13 to penetrate and target pancreatic cancer. These antibodies have been conjugated with our recently developed novel patented superparamagnetic iron oxide nanoparticles (SPIONS) to deliver therapeutics specifically to pancreatic tumors. In this study, we are using curcumin that depletes tumor microenvironment and gemcitabine to investigate the efficacy of the MUC13 conjugated SPION in delivery of therapeutic drugs. Our results demonstrate that enhanced uptake of MUC13-SPION formulation in MUC13 positive (MUC13+) PanCa cells, compared with MUC13 null (MUC13-) cells as demonstrated by immunofluorescence, Prussian blue staining and flow cytometry experiments. Interestingly, the formulation resulted in sustained delivery of curcumin (CUR), enhanced inhibition of cell proliferation, migration and invasion in MUC13+ cells as compared with MUC13- cells, which suggests the targeting efficacy of the formulation. In PanCa orthotopic mice model, MUC13-SPION efficiently targeted pancreatic tumors resulting in significant tumor accumulation. We observed inhibition of tumor volume, metastasis, gem resistance and improved survival in mice treated with the formulation. Additionally, the tumor tissues from treated mice showed extensive downregulation of PCNA and expression of key proteins in SHH pathway, such as SHH, Gli-1, Gli-2, Patched 1, SMO, which has been associated with cancer progression and drug resistance. In conclusion, the results indicate high therapeutic significance of MUC13-SPIONS for achieving pancreatic tumor specific delivery of drugs. Citation Format: Nirnoy Dan, Saini Setua, Poornima Shaji, Sonam Kumari, Murali Mohan Yallapu, Sheema S. Khan, Subhash Chauhan. Antibody mediated targeted drug delivery approach for pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3209.

Abstract 4677: Characterizing resistant and metastatic phenotypes to pharmacological ascorbate in pancreatic cancer

Abstract Background and purpose: Pharmacological ascorbate (P-AscH) is a prooxidant that oxidizes to produce high levels of hydrogen peroxide. It is currently being investigated as an anti-cancer neoadjuvant for pancreatic cancer (PC). In phase I clinical trials, P-AscH has generated encouraging results in terms of efficiency and safety. However, 50% of patients do not respond to P-AscH suggesting that resistance occurs in a subset of patients. We have generated PC cell lines resistant to P-AscH to characterize mechanisms of resistance. Methodology: PANC-1 and MIA PaCa-2 PC cell lines were treated with a stepwise progression of increasing concentrations of P-AscH until 10-fold IC50 concentration was fully tolerated (AscR, ascorbate resistant) as determined by clonogenic survival. Once resistance was achieved, various redox enzyme protein expression and activity were measured to determine their role in resistance to P-AscH. Proliferation and cell cycle analysis were conducted on resistant and sensitive cells. An RNA sequencing screen was conducted as an unbiased approach to identify potential candidates crucial for resistance. Finally, phenotypes associated to increased metastatic potential, including collagen invasion and in vivo tumor colonization were explored for characterization. Results: PANC-1 and MIA PaCa-2 AscR cells developed unique mechanisms to tolerate high levels of P-AscH. PANC-1 AscR cells almost exclusively rely on catalase to detoxify H2O2 generated during P-AscH treatments, while MIA PaCa-2 AscR cells do not. It is interesting to note that not every redox enzyme was upregulated in response to P-AscH treatments, including GPx1/4. The AscR cell lines also differed in growth rates. PANC-1 AscR cells developed a faster proliferation rate, whereas MIA PaCa-2 AscR cells significantly decreased their growth. This is consistent with a shortened G1/G0 cell cycle phase and an accumulation in G2/M, respectively. The RNA sequencing screen revealed a metastatic signature in association with resistance to P-AscH, including upregulation of the PI3K/AKT axis. We observed a significant increase in collagen matrix invasion, as well as metastatic colonization in vivo. Additionally, we have observed increased expression of active AKT in both AscR cell lines, indicating a potential mechanism for the increased metastatic phenotype. Conclusion: Our findings demonstrate distinct mechanisms for AcsR cells to tolerate high doses of P-AscH. Although catalase has demonstrated to be a key factor in controlling redox flux, it may not be necessary for all cell types. Not only can P-AscH resistance alter redox enzyme expression, but we have also observed substantial increase in metastatic potential to drive invasion and tumor colonization. In summary, our data indicate a potential route for PC to tolerate high levels of P-AscH and may explain how some patients do not respond to this treatment regimen. Citation Format: Amanda N. Pope, Brianne R. O'Leary, Juan Du, Garry R. Buettner, Michael D. Henry, Joseph J. Cullen. Characterizing resistant and metastatic phenotypes to pharmacological ascorbate in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4677.

Abstract 7125: Inhibition of IDH1 impairs homologous recombination and induces sensitivity to PARP inhibitor in pancreatic cancer

Abstract Introduction: Pancreatic ductal adenocarcinoma (PDAC) is a major cause of cancer-related deaths in the United States. While Poly (ADP-ribose) polymerase (PARP) inhibitors hold promise in treating PDAC with Homologous Recombination Deficiency (HRD). However, HRD occurs in only 10% of cases, leaving 90% with intact Homologous Recombination Proficiency (HRP). Our research highlights the key role of wild-type isocitrate dehydrogenase 1 (IDH1) in maintaining cellular function. We found that inhibiting IDH1 increases DNA damage, suppressing the DNA repair pathway crucial for genomic integrity. This makes cancer cells susceptible to PARP inhibitors, offering a new PDAC treatment approach. Methods: The effect of IDH1 inhibition (Ivosidenib) combined with PARP inhibition (Olaparib) on in vitro growth inhibition were assessed through Trypan blue and PicoGreen in drug combination assays. Additionally, we investigated the molecular mechanism underlying the synergistic effects of drug combination. To further evaluate the therapeutic potential of IDH1 inhibition in combination with PARP inhibitors, we examined tumor growth in xenograft models of PDAC in athymic nude mice. Results: Our data report that, mechanistically, IDH1 inhibition decreased expression of HR DNA repair pathway molecules, such as BRCA1 and BRCA2, and leading to decreased HR repair efficiency in pancreatic cancer cells. Short-term cell viability data demonstrated that targeting IDH1 with ivosidenib when combined with DNA-damaging agent (Olaparib) had a synergistic effect in HRP cell lines (MiaPaCa-2 and Panc-1) with a positive synergy score and Bliss score greater than 1. Additionally, we assessed long-term cell survival using colony formation assays, which yielded a dramatic reduction in cell survival for both Panc1 and MiaPaCa-2 cells when olaparib was combined with ivosidenib, as compared to single-agent controls. Consequently, this reduction increased the levels of apoptosis induced by olaparib. Furthermore, we discovered that these two compounds complemented each other in DNA damage response, leading to an increase in the DNA damage biomarker γ-H2AX. In vivo studies using xenograft models demonstrated that the combination of ivosidenib and olaparib synergistically enhanced anti-tumor activity as compared to either single-agent used alone. Conclusion: Our data provides insights into the mechanisms underlying the susceptibility of PDAC tumor growth to a dual treatment approach involving an IDH1 inhibitor and a PARP inhibitor, particularly in the context of HRP cancer. This highlights the promise of precision medicine for pancreatic cancer treatment, though further pre-clinical studies are needed for validation and refinement. Citation Format: Mehrdad Zarei, Omid Hajihassani, Hallie J. Graor, Alexander W. Loftus, Soubhi Tahhan, Faith Nakazzi, Parnian Naji, Luke D. Rothermel, Jonothan R. Brody, Jordan M. Winter. Inhibition of IDH1 impairs homologous recombination and induces sensitivity to PARP inhibitor in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7125.

Abstract 7202: Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells

Abstract Pancreatic cancer (PC) is one of the most malignant cancers with limitation of treatment options such as resection surgery, radiation therapy and gemcitabine-based chemotherapy. To treating PC patients, gemcitabine-based chemotherapy is common and effective for PC, acquired gemcitabine resistance is one of the major reasons for treatment failure. Therefore, there is a need to suggest effective strategies and novel therapeutic approach for gemcitabine-resistant PC. Protein Kinase C β1 (PKC β1) is known as involved in multiple signal transduction related to oncogenic functions in cancer. We suggested that PKC β as one of the novel biomarker of drug resistance and further investigated the molecular mechanism. Among the natural products as small molecule inhibitor, we found that evodiamine has potent antitumor activity and various biological activities. Based on various biological activities of evodiamine, the scaffold was synthesized and investigated for antiproliferative and antitumor activities against gemcitabine resistant PANC-1 (PANC-GR) cells. Also, target validation experiment was employed to elucidate the molecular mechanism and verifying the target to overcoming gemcitabine resistance. Mechanistically, evodiamine derivatives have shown that inhibition of PKC β1 can modulate the proliferation of PANC-GR cells and exhibited tumor growth inhibitory activity in xenograft mouse model. Keywords: Pancreatic cancer cell, Gemcitabine resistance, Protein Kinase C β1 (PKC β1), Molecular mechanism Acknowledgements: This research was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (RS-2023-00273240). Citation Format: EunSeo Bae, Yijae Lim, Junhwa Hong, Woong Sub Byun, Simin Chun, Suckchang Hong, Sang Kook Lee. Strategy of targeting PKCβΙ protein to overcoming the acquired gemcitabine resistant pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7202.

Abstract 5877: Disulfiram and its metal complexes reversed hypoxia induced stemness and synergized with first line drugs in primary patient derived pancreatic ductal adenocarcinoma cells

Abstract Pancreatic ductal adenocarcinoma (PDAC) has a dismal 5-year survival rate (12%) and is predicted to become the second leading cause of cancer related deaths by 2030. The main treatment option for advanced PDAC, gemcitabine (GEM) and nab-paclitaxel (PAC) chemotherapy, has limited efficacy due to adverse toxicities and chemoresistance. Extensive desmoplasia in the PDAC microenvironment induces hypoxia that drives epithelial to mesenchymal transition (EMT) and promotes cancer stem cells (CSCs) leading to metastasis and acquired resistance. Drugs that target CSCs and EMT to overcome chemoresistance could improve patient outcome. Disulfiram (DSF), an FDA approved anti alcoholism drug, has excellent anticancer activity on chelation with Cu2+/Zn2+ ions to form the anticancer metabolites, Copper or Zinc Diethyldithiocarbamate (CuDDC or ZnDDC). The anticancer application of the current oral version of DSF is prevented by its short plasma half-life (< 4 minutes) and separate administration of oral Cu/Zn supplement leading to bioavailability issues. A stable, long circulating, injectable formulation of DSF, CuDDC or ZnDDC may overcome these pharmacokinetic issues. In this study albumin was used to develop soluble, stable and homogenous CuDDC and ZnDDC nanoparticles (Alb-CuDDC, Alb-ZnDDC) and their efficacy was compared with free DSF-Cu in a panel of normoxic, hypoxic and spheroid cultures of patient PDAC cells derived from primary, circulating and metastatic sites. Hypoxia and spheroid cultures of PDAC cells were highly resistant to GEM and PAC and had increased expression of CSC markers such as ALDH, CD133, ABCG2 and CA9. Alb-CuDDC and Alb-ZnDDC were cytotoxic to all PDAC cells (IC50s ~300 nM and ~7000 nM, respectively) in normoxia and hypoxia and synergized with GEM and PAC. While DSF-Cu and Alb-CuDDC significantly reduced the expression of CSC markers and inhibited sphere reformation and migration of PDAC cells, Alb-ZnDDC was less effective in inhibiting these features. Therefore, the ability of PDAC cells to acquire resistance to Alb-ZnDDC was investigated. After long term exposure (> 4 months) to increasing doses of each drug (DSF-Cu, Alb-CuDDC and Alb-ZnDDC), PANC1 and BXPC3 PDAC cells acquired resistance only to Alb-ZnDDC. PANC1ZR6 and BXPC3ZR5 resistant cells showed increased expression of CSC markers and significant cross-resistance to PAC and GEM suggesting multidrug resistance. Importantly, no cross-resistance to Alb-CuDDC or DSF-Cu was observed, suggesting alternative mechanisms for Alb-ZnDDC. RNA sequencing is underway to identify potential mechanisms involved. To conclude, albumin formulation improved the solubility and stability of DSF-metal complexes. Alb-CuDDC targets CSCs and overcomes resistance in PDAC, similar to free DSF-Cu. Alb-ZnDDC may have alternative mechanisms which are yet to be elucidated. Citation Format: Benjamin J. Small, Ogechi Nkeonye, Vinodh Kannappan, Shalini Kumarasamy, Kate Butcher, Karim Azar, Gowtham Rajendran, Yoshitha Lakshmanan Lakshmanan, Mark Morris, Christopher Heeschen, Yaohe Wang, Weiguang Wang. Disulfiram and its metal complexes reversed hypoxia induced stemness and synergized with first line drugs in primary patient derived pancreatic ductal adenocarcinoma cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5877.

Abstract 663: Irreversible covalent azetidine-based small molecule inhibitors of Stat3 activity block growth of human pancreatic tumors

Abstract The incidence and death rates for pancreatic adenocarcinoma in the US have been increasing by about 1% per year and the death rate has increased by approximately 0.2% yearly. The five-year survival rate has remained below 10% for many years. With surgery, radiation, and chemotherapy being the main treatment options to extend survival or for symptom relief, there is an urgent unmet need for effective new treatment options. Signal Transducer and Activator of Transcription (Stat) 3, one of the Stat family members, is aberrantly activated in human pancreatic and many other cancers. Aberrantly-active Stat3 promotes abnormal tumor-cell intrinsic and extrinsic mechanisms, including dysregulation of gene expression and mitochondria energy metabolism in the tumor cells, and suppression of immune cell functions in the tumor microenvironment. Stat3 is therefore an important target for therapeutic development. Herein we present two small molecules, H182 and H333, which are covalent inhibitors of Stat3 and that potently block Stat3 DNA-binding activity in vitro, with IC50 0.66-0.98 µM. H182 and its structural analog, H333 bind Stat3 via irreversible covalent interactions with key cysteine residues in the Stat3 DNA-binding domain to induce a time-dependent inhibition of Stat3 activity. Both compounds inhibit intracellular constitutive Stat3 tyrosine phosphorylation and induce loss of viable cells and apoptosis in vitro of human pancreatic Panc-1 and Mia-Paca2 cells. H333 is 13-fold more specific and H182 is 4-fold more specific against tumor cells over normal cells. Furthermore, MiaPaca-2 cells treated with H182 and analyzed by Seahorse showed dramatically decreased mitochondria respiration. Notably, xenograft models of MiaPaca2 treated with H182 or H333 via i.p. every other day for 27 days showed dramatic growth inhibition. Collectively, our results identify H182 and H333 as therapeutically-viable small molecules with unique irreversible mechanism of Stat3 inhibition which accounts for their strong antitumor effects against human pancreatic tumor xenografts. Citation Format: Yue Chen, Ning Zhai, Peibin Yue, Christine Brotherton-Pleiss, Wenzhen Fu, Kayo Nakamura, Weiliang Chen, Marcus Tius, Francisco Lopez-Tapia, James Turkson. Irreversible covalent azetidine-based small molecule inhibitors of Stat3 activity block growth of human pancreatic tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 663.

Abstract 4375: ALPPL2 is involved in MAPK signal pathway of pancreatic cancer

Abstract Background: Alkaline phosphatase placental-like 2 (ALPPL2) is a member of the alkaline phosphatase family. ALPPL2 is currently being investigated as a novel therapeutic target due to its cancer-specific expression. However, our knowledge of ALPPL2 biological function in cancer is limited. Here we describe an interaction between ALPPL2 and MAPK signaling pathway in pancreatic cancer. Materials and Methods: ALPPL2 mRNA expression in a panel of 27 pancreatic cell lines was determined by RNAseq. Protein expression and phosphorylation were measured by Western blot. ALPPL2 or ALPP were overexpressed in pancreas cell lines through a Lentiviral packaging system. MEK inhibitor (trametinib) activity was assessed in the same panel of cell lines using a 6-day cell proliferation assay on a Synentec Cellavista imaging system. MEK inhibitor resistant cell lines were developed by culturing cells in increasing concentrations of MEK162. Results: We hypothesized that pancreatic cancer cells with high ALPPL2 expression may be less sensitive to MEK inhibition. Our study from a panel of 27 pancreatic cancer cell lines showed that there was no correlation between ALPPL2 expression and response to trametinib. Western blot showed that the level of phospho-ERK was reduced in PANC1 and HPAC cells at 6 hours after trametinib treatment. Signaling rebounded at 24 and 48 hours, though it remained below baseline. Surprisingly, ALPPL2 expression increased at 24 and 48 hours after trametinib treatment, however, the mRNA of ALPPL2 and ALPP was down-regulated in three pancreatic cancer cell lines conditioned to be MEK inhibitor resistant. To understand the role of ALPPL2 in the MAPK signaling pathway in response to MEK inhibition, ALPPL2 and ALPP were overexpressed in 2 pancreatic cancer cell lines: YAPC and PSN-1 whose ALPPL2 and ALPP were undetected by Western blot prior to transfection. Overexpression of ALPPL2 or ALPP in YAPC cells resulted in more ERK phosphorylation with no change in total ERK, it also resulted in increased total and phospho-S6, and decreased phospho-STAT3 with no change in total STAT3. The amount of total and phospho-ERK were not changed in PSN-1 with overexpression of ALPPL2 or ALPP, however, it did result in increased total and phospho-S6, decreased phospho-STAT3. Interestingly, the expression of ALPPL2 and ALPP in YAPC cells with ALPPL2 or ALPP overexpression was increased at 48 hours after trametinib treatment. Discussion: To our knowledge, this is the first study to report that ALPPL2 interacts with the MAPK signaling pathway in pancreatic cancer cells. The activated MAPK signaling pathway appears to control ALPPL2 expression. The MAPK signaling pathway may regulate ALPPL2 expression through transcription and protein metabolism. We have also shown that ALPPL2 expression can activate MAPK signaling pathway. Our findings that ALPPL2 expression can be increased after trametinib treatment provide further rationale for targeting ALPPL2 in cancer. Citation Format: Ke Wei Gong, Bilal Hamid, Kenny W. Castro, Martina S. McDermott, Forrest Epstein, Kevin Chau, Chuhong Hu, Jun Zhang, Ming Lu, Benjamin G. Hoffstrom, Neil A. O'Brien, Dennis J. Slamon. ALPPL2 is involved in MAPK signal pathway of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4375.

Abstract 5384: The hypoxia-alleviating agent ITPP restores vascular function in zebrafish xenografts of pancreatic cancer

Abstract Pancreatic cancer mostly manifests as pancreatic ductal adenocarcinoma (PDAC) and is characterized by a highly hypoxic microenvironment that is associated with worse patient survival and resistance to therapy. Hypoxia induces angiogenesis and the resulting leaky and unstructured vessels fail to reoxygenate the tumor mass, thus exacerbating hypoxia and its downstream impact on tumorigenesis. Myo-inositol trispyrophosphate (ITPP) is a non-toxic allosteric effector of hemoglobin shown to reduce tumor growth and enhance survival in mice and rat models of different tumor types. Herein the aim is to assess for the first time the ability of ITPP to effectively treat PDAC tumors in vivo in zebrafish xenografts and to investigate its impact on vascular normalization. To that aim, four PDAC cell lines, AsPC1, Capan1, MIA PaCa2, and PANC1 were included, as well as the angiogenic breast cancer cell line, Hs578t. Cells were grown in appropriate conditions and on injection day, labeling was done with deep red. Labeled cells were then injected in the perivitelline space of anesthetized larvae. The following transgenic larvae were used: those having labeled blood vessels only (Tg(kdrl:DsRed)), labeled blood and lymphatic vessels (Tg(fli1:eGFP)), and double transgenics with labeled gata+ erythrocytes (Tg(fli1:eGFP;gata:dsRed)). One day post injection (dpi) xenografts were sorted based on size and treated by immersion for three consecutive days with control medium or ITPP at a concentration selected based on the maximum tolerated dose assay. Treatment was refreshed daily, and at 4dpi live confocal imaging was conducted on select Tg(fli1:eGFP;gata:dsRed) xenografts. All xenografts were then fixed and subjected to whole mount immunofluorescence. Nuclei were stained with DAPI and anti-Caspase3Asp175 was used as a marker for apoptosis. Imaging was performed using the Zeiss LSM confocal microscope and tumor size, apoptosis and mitotic figures were quantified with ImageJ. Vascular function was defined as the presence of gata+ cells within tumor-related vasculature, while vessel density and infiltration were determined in ImageJ by calculating the percentage of GFP area in the tumor. Thus far results from AsPC1-derived xenografts demonstrate that ITPP leads to a significant decrease in mitotic figures (p=0.0132) and an increase in apoptosis (p=0.0025), with no change in tumor size. Preliminary data reveal a trend of increased functional vasculature in both the AsPC1- and Hs578t- derived xenografts upon ITPP treatment. A trend of decreased vasculature infiltration could also be observed in the ITPP-treated Hs578t-derived xenografts. Based on these results, the zebrafish model could be an appropriate alternative for assessing the anti-tumorigenic activity of ITPP in PDAC in a short turnaround time and could potentially enable the visualization of ITPP’s impact on angiogenesis at single cell resolution. Citation Format: Raefa Abou Khouzam, Filipa Amorim, Ayesha Rifath, Husam Nawafleh, Vanda Povoa, Rania Faouzi Zaarour, Jean Marie Lehn, Rita Fior, Perparim Limani, Salem Chouaib. The hypoxia-alleviating agent ITPP restores vascular function in zebrafish xenografts of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5384.

Abstract 6784: Cancer cell heterospheroids with stromal component used as drug testing and immune cell infiltration models

Abstract 3D cancer cell cultures have enabled new opportunities for replacing compound testing in experimental animals. However, driven by increased understanding of the need for more complex cancer cell models that consider drug resistance and penetration, hypoxia, and immuno-oncology applications, we have developed multicellular tumor heterospheroids composed of cancer cell lines, fibroblasts and immune cells. We have studied heterospheroids of cancer cell lines, HT29, MCF7, PANC1 and SW480 co-cultured with fibroblasts and 1) explored the architectural organization, 2) performed whole transcriptome analysis (WTA) of mono and co-cultures and 3) tested their capacity of immune cell infiltration. The architectural organization was studied in embedded heterospheroids. HT29 and MCF7 cells developed spheroids with the cancer cells surrounding the fibroblasts, whereas PANC1 cells mingled with the fibroblasts and SW480 cells were surrounded by fibroblasts. The fibroblasts expressed FAP-α mRNA as determined by ISH as well as collagen-1 as determined by immunohistochemistry. The hypoxia marker, Ca-IX, and the apoptosis marker, cleaved-Caspase-3, were dominating in the central core of the spheroids but the Ca-IX and Caspase-3 expression was not coordinated. In addition, WTA performed on day-7 heterospheroids, showed upregulated LOX, indicating that hypoxia-related markers known from genuine cancers are upregulated also in heterospheroids. WTA of day-7 mono-cell cultured and hetero-cultured spheroids, showed abundant ECM-, EMT-, and fibrosis-related expression in heterospheroids, thus reflecting a representative tumor-like microenvironment in heterospheroids compared to mono-culture spheroids. In particular, PANC1 spheroids showed a strong EMT profile with abundant FOXC2, TGF-β and TWIST expression. Genes related to Akt/mTOR and EGF pathways were consistently expressed in the tested heterospheroids. Evaluation of the cytotoxicity of anti-cancer compounds was performed using both cell viability and apoptosis assays. Exposure of the NCI drug library composed of 166 cytotoxic compounds to the heterospheroids, interestingly, revealed a complex output with limited correlation between cytotoxic and apoptotic effects. A subset of drug candidates is currently being further examined. PBMC-derived immune cells infiltrate heterospheroids and their infiltration is strongly enhanced after activation. The T cells' ability to infiltrate heterospheroids of different cancer types may serve as models of cold and hot tumors. We conclude that the cancer cell lines determine the architectural structure of heterospheroids, that ECM development is a prevalent part of the heterospheroids, and that the different heterospheroids possess varying ability of immune cell infiltration. Citation Format: Boye Schnack Nielsen, Natasha H. Madsen, Jesper Larsen, Monika Gad, Kim Holmstrøm. Cancer cell heterospheroids with stromal component used as drug testing and immune cell infiltration models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6784.

Abstract 1828: Development and evaluation of novel gemcitabine analog for the treatment of pancreatic cancer

Abstract Purpose: Gemcitabine acts against pancreatic cancer and a wide range of solid tumors and it is known to be rapidly deaminated or metabolized in the blood to an inactive metabolite. To increase its therapeutic levels, gemcitabine is administered at high doses causing severe side effects. To improve its metabolic stability, increase cytotoxic activity, and limit the phenomena of resistance many alternatives have emerged, such as modifying gemcitabine. The purpose of this study was to develop and characterize a novel gemcitabine analog with improved stability and enhanced anticancer activity against pancreatic cancer. Methods: A novel analog of gemcitabine (GemAGY) was designed and synthesized through chemical modification of gemcitabine hydrochloride (GemHCl) at position 4 with hydroxylamine. Gem AGY was characterized using nuclear magnetic resonance (NMR), micro-elemental analysis, and purity determined using High-Performance Liquid Chromatography (HPLC). Pancreatic cancer cell lines (MiaPaCa-2, BxPC3, and PANC-1) were treated with GemHCl and GemAGY. Cytotoxicity, cell migration, clonogenic assay, cell cycle, and apoptosis studies were performed to evaluate the effect of GemAGY against pancreatic cancer cell lines. Results: The percent purity of GemAGY was over 99.6%. GemAGY demonstrated a higher cytotoxic effect against pancreatic cancer cells with a lower half-maximal inhibitory concentration (IC50) value (2.5-fold high) compared with GemHCl. For MiaPaCa-2 cells, the IC50 value of GemAGY was found to be 1.63 ± 0.15 µm compared to GemHCl (4.0 ± 1.7 µm). GemAGY also exhibited higher cytotoxicity in PANC-1 (IC50: 1.7 ± 0.2µm) compared to GemHCl (IC50: 5.6 ±1.3 µm) and the IC50 value of GemAGY (3.2±1.1µm) in BxPC-3 cells was significantly better than GemHCl (5.5±1.0 µm). The cell cycle analysis indicated that GemAGY-treated MiaPaCa-2 cells at 1.50 µm concentration had a higher G0/G1 population (60.24%) compared to GemHCl-treated cells (55%). The cell migration studies showed that GemAGY-treated MiaPaCa-2 cells at 12.5 µm concentration significantly inhibited cell mobility towards the wound area with migrated cells found to be 65 ± 6 compared to Gem HCl (174.3 ± 4.0) (GemAGY vs GemHCl; p<0.0001). Similarly, GemAGY-treated PANC-1 cells at 12.5 µm concentration significantly inhibited cell mobility towards the wound area with (98 ± 5.1) compared to Gem HCl (254 ± 6.6). The quantitative analysis of apoptosis studies showed that GemAGY significantly induced higher apoptosis in a dose-dependent manner in MiaPaCa-2 cells compared to GemHCl as concentration increases (GemAGY vs GemHCl; p <0.0001). Conclusion: This study demonstrates that GemAGY increases the anticancer activity of gemcitabine and may have the potential to improve the chemotherapeutic efficacy of gemcitabine in the treatment of pancreatic cancer. Citation Format: Joy Okoro, Raviteja Bulusu, Esther K. Frimpong, Sherise Rodgers, Bo Han, Xue Zhu, Edward Agyare. Development and evaluation of novel gemcitabine analog for the treatment of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1828.

Abstract 7246: Enhancing PDAC therapy through in vivo correction of KRAS G12D using enIscB-directed base editor combined with ICB

Abstract In this study, we aim to investigate the therapeutic potential of in vivo genetic therapy using AAV-mediated adenine base editor (ABE) delivery for pancreatic ductal adenocarcinoma (PDAC) carrying the KRASG12D mutation (PDACG12D), and further explore its potential when combined with immune checkpoint blockade (ICB). The KRASG12D mutation is a dominant genetic alteration representing a highly sought-after and effective therapeutic target in PDAC. However, the in vivo genetic therapy for KRASG12D in PDAC has been rarely explored. Programmable base editors have been shown to install genetic mutations precisely and have significant therapeutic value, providing a promising strategy for genetic therapy of PDACG12D. Here, we engineered ABEs derived from various programmable nucleases, considering the protospacer adjacent motif (PAM) or target adjacent motif (TAM) sequence. The hypercompact A8e-enIscB demonstrated the highest editing efficiency in HEK293TG12D and PANC-1 cell lines. Subsequently, A8e-enIscB was packaged into a single-AAV system and delivered to humanized mice subcutaneously transplanted with patient-derived organoidG12D (PDOG12D). We found the delayed tumor progression with BE-based genetic therapy. Additionally, a substantial editing efficiency in tumor tissues and lower off-target editing in normal tissues was observed. By comparing single-cell transcriptome sequencing data between BE-treated and non-treated samples, we observed a reprogrammed immune microenvironment characterized by elevated infiltration of cytotoxic CD8+ T cells and NK cells, as well as decreased recruitment of suppressive PMN-MDSCs, Tregs and TAMs upon correction of KRASG12D. Furthermore, AAV-directed ABE genetic therapy could significantly sensitize PDAC to ICB therapy (anti-PD-1, anti-CTLA4) in humanized PDAC PDO/PDX mouse models. Accordingly, an ongoing work in which the genetic therapy combined with ICB phase IA investigator-initialized trial will be designed to evaluate the safety of this regimen. In summary, our study demonstrates the efficiency and safety of innovative genetic therapy for correcting the KRASG12D mutation in PDAC. Furthermore, we demonstrated the therapeutic potential of combining this genetic therapy with ICB. Citation Format: Chao Yang, Qingxiao Fang, Tianxing Zhou, Yongjie Xie, Jun Yu, Jihui Hao. Enhancing PDAC therapy through in vivo correction of KRAS G12D using enIscB-directed base editor combined with ICB [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7246.