Human Pancreatic Cancer Cells Research Articles

TAGLN2 targeted control of ARPC5-mediated activation of the MEK/ERK signaling pathway influences the proliferation, invasion, and metastasis of pancreatic cancer cells

PurposePancreatic cancer (PC) is a common tumor of the digestive tract with an insidious onset and high malignancy potential. Currently, surgery is the only effective treatment modality. Therefore, it is crucial to discover new targeted therapeutic modalities. We studied whether transgelin 2 (TAGLN2) targeted control of actin-related protein 2/3 complex subunit 5 (ARPC5)-mediated activation of the MEK/ERK signaling pathway to Influences the proliferation, invasion, and metastasis of pancreatic cancer cells. MethodsThe effects of TAGLN2 overexpression and knockdown on the proliferative viability and invasive metastatic ability of pancreatic cancer cells were verified through in vitro and in vivo assays via constructing a stable lentiviral transfection of human pancreatic cancer cell lines PANC-1 and SW1990. Bioinformatics analysis was used to predict the relationship between TAGLN2 and ARPC5. These findings were subsequently verified through protein profiling, immunofluorescence (IF), and coimmunoprecipitation (CO-IP) assays. In vitro experiments were also conducted to confirm the effect of TAGLN2 modulation on ARPC5 expression, which subsequently affects the proliferation and invasive metastatic ability of pancreatic cancer cells. The study analyzed the relationship between TAGLN2 and the MEK/ERK signaling pathway through bioinformatics and in vitro experiments with the MEK signaling pathway inhibitor U0126. ResultsTAGLN2 is expressed at high levels in pancreatic cancer cell lines, and its expression is positively correlated with poor prognosis of pancreatic cancer. ARPC5 is a direct target of TAGLN2 and is associated with the MEK/ERK signaling pathway. In vivo and ex vivo experiments confirmed that overexpression of TAGLN2 promoted the proliferation, invasion, and metastasis of pancreatic cancer cells, and silencing ARPC5 reversed these effect. ConclusionOur research revealed that TAGLN2 protein binds to ARPC5 protein and contributes to increased ARPC5 expression and activation of the MEK/ERK signaling pathway. This activation promotes pancreatic cancer cell growth, infiltration, and spread. Hence, TAGLN2 is a potential viable therapeutic target in pancreatic cancer and represents a novel therapeutic approach.

Exosomal HSPB1, interacting with FUS protein, suppresses hypoxia-induced ferroptosis in pancreatic cancer by stabilizing Nrf2 mRNA and repressing P450.

Ferroptosis is a new type of programmed cell death, which has been involved in the progression of tumours. However, the regulatory network of ferroptosis in pancreatic cancer is still largely unknown. Here, using datasets from GEO and TCGA, we screened HSPB1, related to the P450 monooxygenase signalling, a fuel of ferroptosis, to be a candidate gene for regulating pancreatic cancer cell ferroptosis. We found that HSPB1 was enriched in the exosomes derived from human pancreatic cancer cell lines SW1990 and Panc-1. Then, hypoxic SW1990 cells were incubated with exosomes alone or together with HSPB1 siRNA (si-HSPB1), and we observed that exosomes promoted cell proliferation and invasion and suppressed ferroptosis, which was reversed by si-HSPB1. Moreover, we found a potential binding affinity between HSPB1 and FUS, verified their protein interaction by using dual-colour fluorescence colocalization and co-IP assays, and demonstrated the promoting effect of FUS on oxidative stress and ferroptosis in hypoxic SW1990 cells. Subsequently, FUS was demonstrated to bind with and stabilize the mRNA of Nrf2, a famous anti-ferroptosis gene that negatively regulates the level of P450. Furthermore, overexpressing FUS and activating the Nrf2/HO-1 pathway (using NK-252) both reversed the inhibitory effect of si-HSPB1 on exosome functions. Finally, our invivo studies showed that exosome administration promote tumour growth in nude mice of xenotransplantation, which was able to be eliminated by knockdown of HSPB1. In conclusion, exosomal HSPB1 interacts with the RNA binding protein FUS and decreases FUS-mediated stability of Nrf2 mRNA, thus suppressing hypoxia-induced ferroptosis in pancreatic cancer.

Talaromides A-C, Bioactive Cyclic Heptapeptides from Talaromyces siglerae Isolated from a Marine Sponge.

Three new cyclic heptapeptides, talaromides A-C (1-3), were isolated from cultures produced by the fungus Talaromyces siglerae (Ascomycota), isolated from an unidentified sponge. The structures, featuring an unusual proline-anthranilic moiety, were elucidated by analysis of spectroscopic data and chemical transformations, including the advanced Marfey's method and GITC derivatization. Talaromides A and B inhibited migration activity against PANC-1 human pancreatic cancer cells without significant cytotoxicity.

Evaluation of Helium Ion Radiotherapy in Combination with Gemcitabine in Pancreatic Cancer In Vitro.

Pancreatic cancer is one of the most aggressive and lethal cancers. New treatment strategies are highly warranted. Particle radiotherapy could offer a way to overcome the radioresistant nature of pancreatic cancer because of its biological and physical characteristics. Within particles, helium ions represent an attractive therapy option to achieve the highest possible conformity while at the same time protecting the surrounding normal tissue. The aim of this study was to evaluate the cytotoxic efficacy of helium ion irradiation in pancreatic cancer in vitro. Human pancreatic cancer cell lines AsPC-1, BxPC-3 and Panc-1 were irradiated with photons and helium ions at various doses and treated with gemcitabine. Photon irradiation was performed with a biological cabin X-ray irradiator, and helium ion irradiation was performed with a spread-out Bragg peak using the raster scanning technique at the Heidelberg Ion Beam Therapy Center (HIT). The cytotoxic effect on pancreatic cancer cells was measured with clonogenic survival. The survival curves were compared to the predicted curves that were calculated via the modified microdosimetric kinetic model (mMKM). The experimental relative biological effectiveness (RBE) of helium ion irradiation ranged from 1.0 to 1.7. The predicted survival curves obtained via mMKM calculations matched the experimental survival curves. Mainly additive cytotoxic effects were observed for the cell lines AsPC-1, BxPC-3 and Panc-1. Our results demonstrate the cytotoxic efficacy of helium ion radiotherapy in pancreatic cancer in vitro as well as the capability of mMKM calculation and its value for biological plan optimization in helium ion therapy for pancreatic cancer. A combined treatment of helium irradiation and chemotherapy with gemcitabine leads to mainly additive cytotoxic effects in pancreatic cancer cell lines. The data generated in this study may serve as the radiobiological basis for future experimental and clinical works using helium ion radiotherapy in pancreatic cancer treatment.

Senolysis of gemcitabine-induced senescent human pancreatic cancer cells.

Gemcitabine (GEM) is often used to treat pancreatic cancer. Many anti-cancer drugs induce cancer cell death, but some cells survive after cell cycle arrest. Such a response to DNA damage is termed cellular senescence. Certain drugs, including the Bcl-2-family inhibitor ABT-263, kill senescent cells; this is termed senolysis. In this study, we examined the therapeutic benefits of ABT-263 in GEM-induced senescence of human pancreatic cancer cells. Of four pancreatic cancer cell lines (PANC-1, AsPC-1, CFPAC-1, and PANC10.05), GEM induced senescent features in PANC-1 and AsPC-1 cells, including increases in the cell sizes and expression levels of mRNAs encoding interleukin (IL)-6/IL-8 and induction of β-galactosidase. Successive treatment with GEM and ABT-263 triggered apoptosis in PANC-1 and AsPC-1 cells and suppressed colony formation significantly. Senolysis of GEM-induced senescent pancreatic cancer cells by ABT-263 was triggered by a Bcl-xL inhibitor, but not by a Bcl-2 inhibitor, suggesting a central role for Bcl-xL in senolysis. In a xenograft mouse model, combined treatment with GEM and ABT-737 (an ABT-263 analog exhibiting the same specificity) suppressed in vivo growth of AsPC-1 significantly. Together, our results indicate that sequential treatment with GEM and senolytic drugs effectively kill human pancreatic cancer cells.

The UBE2F-CRL5ASB11-DIRAS2 axis is an oncogene and tumor suppressor cascade in pancreatic cancer cells

UBE2F, a neddylation E2, neddylates CUL5 to activate cullin-RING ligase-5, upon coupling with neddylation E3 RBX2/SAG. Whether and how UBE2F controls pancreatic tumorigenesis is previously unknown. Here, we showed that UBE2F is essential for the growth of human pancreatic cancer cells with KRAS mutation. In the mouse KrasG12D pancreatic ductal adenocarcinoma (PDAC) model, Ube2f deletion suppresses cerulein-induced pancreatitis, and progression of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia. Mechanistically, Ube2f deletion inactivates the Mapk-c-Myc signals via blocking ubiquitylation of Diras2, a substrate of CRL5Asb11 E3 ligase. Biologically, DIRAS2 suppresses growth and survival of human pancreatic cancer cells harboring mutant KRAS, and Diras2 deletion largely rescues the phenotypes induced by Ube2f deletion. Collectively, Ube2f or Diras2 plays a tumor-promoting or tumor-suppressive role in the mouse KrasG12D PDAC model, respectively. The UBE2F-CRL5ASB11 axis could serve as a valid target for pancreatic cancer, whereas the levels of UBE2F or DIRAS2 may serve as prognostic biomarkers for PDAC patients.

MSLN induced EMT, cancer stem cell traits and chemotherapy resistance of pancreatic cancer cells

Chemoresistance is one of the main reasons for poor prognosis of pancreatic cancer. The effects of mesothelin (MSLN) on chemoresistance in pancreatic cancer are still unclear. We aim to investigate potential roles of MSLN in chemoresistance and its relationship with proliferation, epithelial-mesenchymal transition (EMT) and cancer stemness of pancreatic cancer cells. Human pancreatic cancer cell lines ASPC-1 and Mia PaCa-2 with high and low expression of MSLN, respectively, were selected. The ASPC-1 with MSLN knockout (KO) and Mia PaCa-2 of MSLN overexpression (OE) were generated. The effects of MSLN on cell phenotypes, expression of EMT-related markers, clone formation, tumor sphere formation, and pathologic role of MSLN in tumorigenesis were detected. Sensitivity of tumor cells to gemcitabine was evaluated. The results showed that adhesion, proliferation, migration and invasion were decreased significantly in ASPC-1 with MSLN KO, whereas increased significantly in Mia PaCa-2 with MSLN OE. The size and the number of clones and tumor spheres were decreased in ASPC-1 with MSLN KO, and increased in Mia PaCa-2 with MSLN OE. In xenograft model, tumor volume was decreased (tumor grew slower) in MSLN KO group compared to control group, while increased in MSLN OE group. Mia PaCa-2 with MSLN OE had a higher IC50 of gemcitabine, while ASPC-1 with MSLN KO had a lower IC50. We concluded that MSLN could induce chemoresistance by enhancing migration, invasion, EMT and cancer stem cell traits of pancreatic cancer cells. Targeting MSLN could represent a promising therapeutic strategy for reversing EMT and chemoresistance in pancreatic cancer cells.

Abstract 4721: Cell death induction via CB2 receptor and TRPV receptor in cannabichromene (CBC) treated human pancreatic cancer cells

Abstract Cannabichromene (CBC: C21H3O2, M.W.: 314.46g) is one of the most abundant nonpsychotropic phytocannabinoids extracted from Hemp species (Cannabis sativa), and can extract using either a hexane/florisil extraction method. Phytocannabinoids contain Δ9-tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD), cannabigerol (CBG), cannabichromene (CBC), and other compounds. CBC can cause strong anti-inflammatory effects in animal models of edema through non-CB receptor mechanisms, but there is little pharmacological study in cancer disease models. In this study, we investigated the molecular mechanism on anti-cancer activity of CBC treatment in human pancreatic cancer cells. MTT assay was performed to determine concentrations for inducing pharmacological effects of CBC in human pancreatic cancer cells. FACS and Annexin V/PI staining analysis showed the increase dead cells by CBC treatment, and Western blot analysis also showed the changes in expression of cell death related proteins by CBC. Moreover, CBC treatment increased expression of CB2 receptor and TRPV receptor, but the anti-cancer effect was restored by double inhibition with SR144528 for CB2 receptor and capsazepine for TRPV receptor, respectively. mRNA-seq analysis showed that 1206 genes were upregulated and 1145 genes were down-regulated by CBC treatment, indicating that some of ferroptosis related genes (HMOX1, CHAC1, GPX4 and NFE2L2) were regulated by CBC treatment. qPCR analysis showed that those genes are increased by CBC treatment in time dependent manner. It was also confirmed that HMOX1 protein expression was increased using Western blot analysis. Therefore, we suggest that CBC induces multiple cell death mechanism including ferroptosis via CB2 receptor and TRPV receptor in human pancreatic cancer cells. Citation Format: Yu-Na Hwang, Keun-Cheol Kim. Cell death induction via CB2 receptor and TRPV receptor in cannabichromene (CBC) treated human 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 4721.

Abstract 5327: Interleukin-1 upregulates dual oxidase 2 expression and ROS production in human pancreatic cancer cells

Abstract Chronic pancreatitis increases the risk of developing pancreatic ductal adenocarcinoma (PDAC) and is associated with enhanced expression of the NADPH oxidase (NOX) isoform dual oxidase 2 (DUOX2). Interleukin-1 (IL-1) is a major upstream pro-inflammatory cytokine secreted by malignant or microenvironmental cells that supports pancreatic inflammation, tumorigenesis, invasiveness, and tumor heterogeneity. Previously, our laboratory demonstrated that the expression of DUOX2, one of seven NADPH oxidase (NOX) family members, is significantly enhanced by a wide variety of pro-inflammatory cytokines, and that DUOX2-related ROS production may contribute to the development of an oxidative, pro-angiogenic microenvironment in PDAC. In the current studies, we have shown that DUOX2 is upregulated and expressed along with its maturation factor, DUOXA2, in several human pancreatic cancer cell lines following exposure to both IL-1α and IL-1ß, two major agonists of IL-1 signaling. Administration of the anti-inflammatory antibody anakinra (an IL-1R1 antagonist) either in conjunction with or after prolonged treatment with IL-1 in vitro ablated induction of DUOX2/DUOXA2 and of IL-8 (CXCL8), a chemokine essential for neutrophil recruitment and a potent promoter of angiogenesis. Increased expression of other NOX family members following IL-1 exposure was not observed. Using CRISPR/Cas9-mediated DUOX2 knockout models, we report that DUOX2 is the major contributor to IL-1-mediated ROS production in PDAC cells. In a panel of PDAC lines, siRNA knockdown of proximal IL-1 signaling nodes, such as MYD88, significantly decreased expression of DUOX2/DUOXA2 and of CXCL8. However, knockdown of IRAK1 or IRAK4, two critical signaling kinases downstream of MYD88, as well as known downstream mediators of IL-1-related transcription (such as NF-κB, STAT1, MEK/ERK), did not affect IL-1-induced DUOX2/DUOXA2 upregulation, suggesting that alternative pathways of IL-1 signaling might be involved in the enhancement of DUOX2 expression by the cytokine. Because IL-1 signaling is known to affect various acetylation/methylation events in epithelial cells, we evaluated the effect of administering the histone acetyltransferase (HAT) inhibitor A-485 with IL-1; we found that A-485 significantly diminished cytokine-induced DUOX2/DUOXA2 upregulation; however, CXCL8 induction was unchanged. These studies suggest that epigenetic modulation of PDAC cells by IL-1 could contribute to DUOX2-induced ROS production and ROS-related inflammatory stress in the PDAC microenvironment. Citation Format: David J. Mallick, Yongzhong Wu, Mariam M. Konaté, Becky Diebold, Smitha Antony, Jennifer L. Meitzler, Guojian Jiang, Jiamo Lu, Krishnendu Roy, James H. Doroshow. Interleukin-1 upregulates dual oxidase 2 expression and ROS production in human 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 5327.

Abstract 4441: The epigenetic factor BMI1 regulates metabolism and tumorigenesis in human pancreatic cancer cells

Abstract Dysregulation of epigenetic factors is a key component of tumorigenesis. BMI1, a member of the polycomb repressor complex 1 (PRC1), is an oncogenic factor studied in many types of cancer, including pancreatic ductal adenocarcinoma (PDAC). PDAC is the third most common cause of cancer-related death in the United States and investigation of the biology involved in transformation is critical for improving outcomes in this devastating disease. In PDAC, BMI1 is required for initiation of pancreatic cancer in mice and enhances in vitro growth of human and murine tumor cell lines. CRISPR-mediated knock out of BMI1 results in reduced subcutaneous and orthotopic tumor growth in mice and decreased expression of genes related to metabolism, specifically glycolysis, and cell proliferation. BMI1 has also been implicated in regulation of metabolism in other epithelial tumor types, including ovarian cancer. Given these preliminary findings, we hypothesized that loss of BMI1 in multiple human PDAC cell lines would result in altered metabolic activity, reducing the growth and tumorigenic properties of these cells. We demonstrated that BMI1 expression is higher in PDAC cell lines compared to normal pancreatic epithelial cells and normal human donor pancreatic tissue. Following CRISPR-mediated BMI1 knock out in human PDAC cell lines, we investigated the alterations to metabolism using metabolic flux analysis. Loss of BMI1 resulted in lower basal and compensatory rates of glycolysis and increased oxygen consumption rates compared to wild-type cells. Metabolomic analysis demonstrated reduction in all the enzymes involved in the glycolysis pathway with loss of BMI1. Cell growth was reduced by loss of BMI1 in vitro, and orthotopic injection into mice of human cells with BMI1 knock out resulted in decreased tumor size compared to wild-type, recapitulating these findings in vivo. Together, these data identify a role of BMI1 in promotion of tumor growth through regulation of metabolism in pancreatic cancer. Experiments are ongoing to determine the underlying mechanism of this regulation and implications on therapeutic targeting with BMI1/PRC1 complex inhibitors in conjunction with traditional chemotherapy. Citation Format: Jamie N. Mills, Dominik Awad, Heather K. Schofield, Joyce K. Thompson, Hannah Watkoske, Damien Sutton, Nicholas Nedzesky, Donovan Drouillard, Zeribe Nwosu, Carlos Espinoza, Yaqing Zhang, Annachiara Del Vecchio, Christopher J. Halbrook, Marina Pasca di Magliano, Costas A. Lyssiotis, Filip Bednar. The epigenetic factor BMI1 regulates metabolism and tumorigenesis in human 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 4441.

Abstract 2093: Co-treatment with KRAS G12D inhibitor MRTX1133 plus TTFields against human pancreatic and Colorectal cancer cell lines results in synergistic up-regulation of cleaved PARP in KRAS G12D & unexpectedly in KRAS G12V as well

Abstract Background: Both colorectal and pancreatic cancers are major global health issues and among deadliest cancers with great disease burden. The most commonly mutated oncogenic alteration in human cancers is KRAS, which is prevalent in pancreatic malignancies. The KRAS G12D mutation subtype is present in more than 40% of pancreatic ductal adenocarcinoma (PDAC). To this date there is no available targeted therapy options for patients with KRAS subtype mutations. MRTX1133 has been identified as a non-covalent, potent, and selective inhibitor of KRASG12D. This small molecule inhibitor has been shown to suppress KRASG12D signaling in cells and in vivo. Tumor Treating Fields (TTFields) therapy is a novel approach to treating cancer, the electric fields alter the behavior of cancer cells and prevent them from growing and dividing. We hypothesize that the co-application of MRTX1133 with TTFields will enhance the effects of MRTX1133 in PDAC and colorectal cancer (CRC). Martials and Methods: PDAC cell line CFPAC1 with KRAS G12 V mutation and LS513 CRC cell line with KRAS G12D Mutation were treated with same dose of MRTX1133 (500 nM) and were co-treated with 150kHz TTFields. After 48 hours western blot was used to probe for cleaved PARP, cleaved C3, phosphor-ERK and DUSP6. Results: In both KRAS G12D & KRAS G12V cell lines, synergistic upregulation of cPARP was observed following 48-hour co-treatment. Synergistic inhibition of pERK happened in KRAS G12D cell line but no change in pERK level following TTFields or MRTX1133 treatment was seen. Upregulation of cC3 in KRAS G12D happened in only co-treatment conditions. DUSP6 levels increased following MRTX1133 treatment in KRAS G12V cell line. Conclusions: The surprising synergistic upregulation of cPARP in both KRAS G12V and G12D cells following co-treatment of KRAS G12D inhibitor MRTX1133 and TTFields can bring hope for other KRAS mutation subtypes as well as G12D. the increase in cPARP in KRAS G12V with no effect on pERK is particularly interesting and demonstrates the need of more studies to investigate the mechanisms of this synergy. Citation Format: Vida Tajiknia, Praveen Srinivasan, Maximilian PInho-Schwermann, William MacDonald, Connor Purcell, Wafik El-Deiry. Co-treatment with KRAS G12D inhibitor MRTX1133 plus TTFields against human pancreatic and Colorectal cancer cell lines results in synergistic up-regulation of cleaved PARP in KRAS G12D & unexpectedly in KRAS G12V as well [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 2093.

Abstract 3140: BL-M05D1, a novel claudin 18.2-targeting ADC, demonstrates specific potent anti-tumor efficacy in preclinical evaluation

Abstract Claudin 18.2, is a member of the tight junction protein family, and an isoform of claudin18. It is therapeutically targeted in cancer due to its limited expression in normal tissue and prevalent expression in a variety of human carcinomas. To develop a promising therapeutic anti-tumor agent, we generated BL-M05D1, an anti-Claudin 18.2-Ed-04 ADC. It is comprised of a novel, specific monoclonal antibody against Claudin 18.2 (5103F3), having a wt Fc that can mediate ADCC and CDC in vitro. BL-M05D1 is composed of (5103F3), a cathepsin B cleavable linker, and a novel topoisomerase I inhibitor agent (Ed-04). The novel Ed-04 is a derivative of the alkaloid camptothecin and mediates cell cycle arrest at the S phase and subsequent apoptosis. BL-M05D1 achieves a high drug-to-antibody-ratio (DAR=8) with a highly stable linker and is readily internalized and trafficked to lysosomal cellular compartments. The antitumor efficacy of BL-M05D1 was evaluated in xenograft tumor models. BL-M05D1 exhibited strong tumor inhibition capacity toward the human gastric cancer cell MKN-45-Claudin18.2 (#C11D) xenograft model, and human pancreatic cancer cell Patu8988s-Claudin18.2 (#C7G) xenograft model. In summary, these studies suggest BL-M05D1, a novel Claudin 18.2-targeting ADC, is potentially efficacious in the treatment of Claudin 18.2-expressing carcinomas. The clinical phase I is being undertaken to evaluate safety, dosing and observations of preliminary signs of efficacy. Citation Format: Weili Wan, Kelcey Dinkel, Austin Sanford, Shuwen Zhao, Shi Zhuo, Yong Zhang, Lan Chen, Ruigang Li, Jahan Salar Khalili, Xiao Sa, Yongqi Yan, Xuejiao Shen, Yi Zhu. BL-M05D1, a novel claudin 18.2-targeting ADC, demonstrates specific potent anti-tumor efficacy in preclinical evaluation [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 3140.

Abstract 7134: Treatment of pancreatic cancer cells with tumor treating fields (TTFields) and PARP inhibitors

Abstract Background: Therapeutic options for advanced stage pancreatic cancer are limited. Patients harboring germline BRCA mutations benefit from PARP inhibitors (PARPi); unfortunately, such mutations are rare in pancreatic cancer. Tumor Treating Fields (TTFields), electric fields that disrupt cellular processes crucial for cancer cell viability, have shown effectiveness against pancreatic cancer cells, and are currently under clinical investigation for the treatment of patients with pancreatic cancer. The mechanism of action of TTFields in various cancer types has suggested involvement of BRCA downregulation. The current study examined the potential sensitization of BRCA wild-type pancreatic cancer cell lines to PARPi with TTFields application. Methods: BxPC3 and AsPC1 human pancreatic BRCA wild-type cancer cells were treated for 72 h with TTFields (frequency of 150 kHz; intensity of 1 and 0.5 V/cm RMS, respectively), using the inovitro device. The PARPi niraparib and olaparib were each administered to the cells at various concentrations, with or without co-application of TTFields. At treatment cessation, cell count, colony formation, and apoptosis were measured. Results: Applying PARPi to pancreatic cell lines yielded a dose-dependent cytotoxic and anti-clonogenic effects, and induced apoptosis. TTFields application also induced such effects when applied alone, while delivery of TTFields together with PARPi amplified the effects demonstrated by PARPi alone. Conclusions: Concomitant application of TTFields and PARPi in BRCA wild type pancreatic cancer cells exhibits a potential improvement relative to the mono-therapies. This could be rationalized based on the previously demonstrated ability of TTFields to induce a state of BRCAness in cancer cells, and suggests benefit for TTFields and PARPi co-treatment in the absence of background BRCA mutations. Citation Format: Hila Ene, Kerem Ben Meir, Antonia Martinez-Conde, Roni Frechtel-Gerzi, Hila Gabay, Daria Gerasimova, Rotem Engelman, Eyal Dor-On, Adi Haber, Moshe Giladi, Yoram Palti. Treatment of pancreatic cancer cells with tumor treating fields (TTFields) and PARP inhibitors [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 7134.

Abstract 3356: Inhibiting phospholipase D1 reduces pancreatic carcinogenesis in mice

Abstract New therapeutic targets are needed for pancreatic ductal adenocarcinoma (PDAC), a leading cause of cancer-related death worldwide. Phospholipase D (PLD) is a lipid-signaling enzyme that appears to play a critical role in cell proliferation, survival/apoptosis, and downstream oncogenic transformation. Elevated PLD1 or PLD2 (the two classical mammalian isoforms) activity has been shown to promote tumor progression in various cancer types, however, the role and mechanisms of PLD in pancreatic cancer are not yet understood. Thus, the objective is to determine the role of PLD1 regulation in pancreatic carcinogenesis through genetic and pharmacological inhibition. To evaluate the role of PLD1 in tumor growth, we subcutaneously transplanted human MIA PaCa-2 pancreatic cancer cells expressing endogenous PLD1 levels (Ctr KD cells), or MIA PaCa-2 cells in which PLD1 was knocked down (Pld1 KD cells), into immunodeficient nude mice. After 18 days post implantation, tumors that arose from Pld1-KD cells presented a significantly smaller tumor size (p<0.05) and had reduced levels of Bcl-xL and Bcl-2, compared to controls (Ctr KD). Then, to assess the role of PLD1 in the tumor microenvironment, we implanted KPC pancreatic cancer cells into C57BL/6 wild-type (WT) or C57BL/6 PLD1 knockout (Pld1−/−) mice with and without treatment with gemcitabine. Fourteen days after tumor implantation, the growth of KPC tumors was attenuated in Pld1−/− mice by 49% (p<0.05). Treatment with gemcitabine reduced tumor growth by 51.6% (p<0.05) in WT mice and by 79.5% (p<0.03) in Pld1−/− mice. Moreover, we evaluated the effects of PLD1 genetic ablation by crossing LSL-KrasG12D/+; Ptf1Cre/+ (KC) mice into PLD1 knockout (Pld1−/−) mice to generate KC; Pld1−/− mice. At 8 months of age, KC; Pld1−/− mice had significantly smaller pancreases (p<0.05) compared to KC mice. Interestingly, PLD1 ablation increased phosphorylation of ERK and c-Jun in KC; Pld1−/− mice compared to KC mice. Finally, to assess whether pharmacological inhibition of PLD can inhibit pancreatic carcinogenesis, KC mice received daily intraperitoneal injections of a small molecule inhibitor of PLD1 and PLD2 (FIPI) at a dosage of 3 mg/kg of body weight for a duration of 5 weeks. Treatment with FIPI reduced acinar-to-ductal metaplasia (p<0.05) and reduced cell proliferation (p<0.01), when compared to vehicle-treated KC controls. Additionally, FIPI treatment was safe demonstrating no significant differences in body weight between the groups and no significant alteration in the serum levels of liver enzymes, including aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase. In conclusion, these findings reveal PLD1 plays a critical role in pancreatic carcinogenesis and might represent a novel therapeutic target. Citation Format: Hala Amer Addassi, Karen Matsukuma, Gerardo G. Mackenzie. Inhibiting phospholipase D1 reduces pancreatic carcinogenesis in mice [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 3356.

Electrochemiluminescence biosensor for specific detection of pancreatic ductal carcinoma through dual targeting of MUC1 and miRNA-196a

Pancreatic ductal adenocarcinoma (PDAC) poses significant diagnostic challenges due to its asymptomatic nature in its early stages, low specificity of conventional in vitro assays, and limited efficacy of surgical interventions. However, clinical specificity of the current serum biomarkers is suboptimal, leading to diagnostic inaccuracies and oversights. Therefore, this study introduced a novel dual-target electrochemiluminescence (ECL) biosensor to address these critical issues. The ECL biosensor synergistically employs the serum biomarker MUC1 and microRNA-196a to detect early-stage PDAC precisely. While MUC1 is a differential marker between normal and cancerous pancreatic cells, its standalone diagnostic performance is limited. However, integrating miRNA-196a as a complementary marker substantially enhances the specificity of the assay. This biosensor exhibits distinct ECL signal modulation—"on-off” in the presence of MUC1 and “off-on” upon concurrent detection of MUC1 and miRNA-196a. The biosensor achieves remarkably low limits of detection (LODs) at 0.63 fg mL−1 and 4.57 aM for MUC1 and miRNA-196a, respectively. Thus, it facilitates the real-time differentiation between human normal pancreatic (hTERT-HPNE) and pancreatic cancer (PANC-1) cells in authentic biological matrices. This innovative approach heralds a significant advancement in the early and specific detection of PDAC, offering promising prospects for clinical translation and the broader landscape of cancer diagnostics.

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 1594: Pancreatic cancer and T-cell crosstalk-induced MUC4 expression attenuates T-cell-mediated response

Abstract Background: While T-cell-based immunotherapy emerged as a promising tool for cancer management, clinical trials and translational studies revealed that cancer cells develop resistance by modulating tumor microenvironment and cell-intrinsic mechanisms. Pancreatic cancer (PC), consisting of dense stroma, immunosuppressive environment, and aberrant mucin expression, has a dismal survival rate and responds poorly to immunotherapies. MUC4, a member of the mucin family, has been reported to block lymphokine-activated killer cells and induce apoptosis of cytotoxic T-cells, suggesting its possible role in immune modulation. However, how the T-cell secretome influences MUC4 expression in PC and its role in modulating the T-cell response is poorly investigated. Method: The scRNA-seq data analysis and primary T-cell conditioned media (CM) were utilized to investigate the MUC4 and T-cell crosstalk. T-cell CM-treated murine PC cell line (KCT-3266) was analyzed by RNA-seq analysis followed by MUC4 silencing studies to investigate its role in evading T-cell response. The subcutaneous murine model was utilized to investigate the influence of MUC4 KO on immune cells and cytotoxic cell infiltration. The RNA isolated from tumor tissues from KrasG12D/+, Trp53R127H/+, Pdx-1-Cre (KPC), and Muc4 knockout (KPMC) murine models were used for PanCancer immune profiling. Results: The scRNA-seq analysis suggests that intratumoral T-cells positively correlate with MUC4 expression in PC patients. The activated T-cell CM consisting of predominantly IL-2, IFN-γ, and TNF-α cytokines, significantly induce the expression of MUC4 transcriptionally and translationally in both human (SW1990 and COLO357) and murine (KCT-3248 and KCT3266) PC cell lines. RNA-seq analysis from T-cell CM-treated cancer cells revealed that T-cell secretome induced the pathways related to cancer cell death. The CRISPR knockout of MUC4 in PC cells showed increased expression of cleaved caspase-3 after T-cell CM treatment, indicating that MUC4 plays a protective role against the T-cell CM-mediated killing. Subcutaneous implantation of MUC4 proficient and deficient PC cells on the flanks of C57BL/6 immunocompetent mice demonstrated a significantly higher infiltration of CD3 positive and cytotoxic T-cell infiltration in the MUC4 deficient tumors, resulting in significantly lower tumor weight. The PanCancer immune profiling also showed that depletion of Muc4 increases the T-cells and cytotoxic T-cell signaling scores in the KPMC tumor tissues compared to KPC. Conclusion: T-cell secretome induces MUC4 expression in pancreatic cancer cells, and the increased MUC4 expression reduces T-cell infiltration and protects PC cells against T-cell-mediated killing. Citation Format: Xiaoqi Li, Imran Khan, Rachel Kehrberg, Zahraa Wajih Alsafwani, Rakesh Bhatia, Sushil Kumar, Surinder K. Batra. Pancreatic cancer and T-cell crosstalk-induced MUC4 expression attenuates T-cell-mediated response [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 1594.

Abstract 7291: Detection of a truncated form of multidrug resistance protein 1 (MRP1) in plasma sEVs derived from cancer patients

Abstract Multidrug resistance protein 1 (MRP1/ABCC1) is an ATP dependent transmembrane efflux pump that confers to drug resistance. Overexpression of MRP1 has been observed in both pancreatic ductal adenocarcinoma (PDAC) and breast cancer tissues. Numerous proteomics studies have revealed the presence of MRP1 in small extracellular vesicles (sEVs) released from cancer cells. Cancer-derived sEVs are known to be released into the circulation, thus becoming attractive candidates for non-invasive biomarker development. However, whether the MRP1 level in plasma sEVs is indicative of human cancer has not been evaluated. This study examined the MRP1 expression in plasma sEVs derived from patients with PDAC, breast and colon cancer, and age- and gender-matched healthy subjects. The patient plasma samples were obtained primarily from the NCI-sponsored Cooperative Human Tissue Network and Stephenson Cancer Center. Healthy plasma samples were provided by the Oklahoma Blood institute. Human pancreatic cancer cell lines PANC-1, MIA PaCa-2 and BxPC-3, and the pancreatic ductal cell line hTERT-HPNE were tested for MRP1 expression prior to examination of plasma samples. Cellular and plasma sEVs were isolated using the double filtration followed by polymer precipitation method. Western blot was performed to assess the expression level of MRP1 and proteomics was applied to confirm the detection of a truncated form of MRP1 in plasma sEVs. MRP1 expression was detected in the sEVs derived from all three pancreatic cancer cell lines but absent in the sEVs from the HPNE line. Overexpression of a truncated MRP1 protein was detected in plasma sEVs derived from patients with early stage (stage I-IIA) and late stage (III-IV) PDAC, compared with that from matched healthy subjects (n=17 for each group). Similar findings were evident in plasma sEVs from patients with breast cancer (n=7), while the results remained inconclusive in plasma sEVs from patients with colon cancer (n=7). Protein structure analysis indicated that the truncated form of MRP1 likely consists of the regions between the QCRL-1 motif and the C-terminus of the protein. Proteomic analysis detected the peptides derived from the C-terminus region, consistent with the structural analysis. Furthermore, the truncated form of MRP1 can only be detected using antibodies against the epitopes in the C-terminus and QCRL-1 region of MRP1 protein. In summary, we have detected a truncated form of MRP1 protein in plasma sEVs derived from cancer patients, and the level of its expression is significantly elevated in patients with PDAC and breast cancer. Citation Format: Kritisha Bhandari, Jeng Shi Kong, Chao Xu, Ajay Jain, Wei-Qun Ding. Detection of a truncated form of multidrug resistance protein 1 (MRP1) in plasma sEVs derived from cancer patients [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 7291.

Abstract 7223: A triplet therapeutic strategy targeting MEK, BCL-XL, and EGFR, for KRAS-mutant pancreatic ductal adenocarcinoma

Abstract KRAS mutations drive over 90% of pancreatic cancers, but KRAS has been proven difficult to target. Downstream of KRAS, MEK inhibition in combination with BCL-XL inhibition is synthetically lethal and an effective treatment for gynecologic, but not colorectal malignancies. Like colorectal cancer, pancreatic cancer often exhibits aberrant HER/EGFR activity. We hypothesized that a triplicate regimen targeting MEK, BCL-XL, and EGFR/HER would be effective for pancreatic cancer. Trametinib (MEK inhibitor), Afatinib (pan-EGFR/HER inhibitor), and Navitoclax (BCL-XL inhibitor); or DT2216 (a BCL-XL/BCL-1 proteolysis targeting chimera, PROTAC) were explored using various combinatorial strategies. These drug combinations were tested using four primary human pancreatic cancer cell lines using live cell imaging (Incucyte) and an in vivo murine model. Group comparisons were analyzed using one-way ANOVAs, and adjusted p-values <0.05 were considered significant. We observed that no single-agent treatments were effective. MEK inhibition plus anti-BCL-XL (Trametinib + Navitoclax or Trametinib + DT2216) demonstrated efficacy in one of the four cell lines. We noted synergistic effects on reduced cell growth and increased cell death when EGFR/HER inhibition was included by the administration of Afatinib. The triplet combination resulted in synergistic effects in three of four cell lines with Navitoclax and four of four cell lines with DT2216 (q<0.05). This effect was confirmed with DT2216 inhibition of BCL-XL in an in-vivo murine model. In conclusion, our study shows that a combinatory strategy targeting MEK, BCL-XL, and pan-EGFR/HER receptor kinase shows significant synergistic effects in pancreatic cancer. Clinical trials that assess the efficacy and safety of this strategy for patients with KRAS-mutant pancreatic cancer are warranted. Our data also suggests that novel KRAS inhibitors as monotherapy are likely to fail. Citation Format: Gerik W. Tushoski-Alemán, Alexandra J. Crespin, Chibeze J. Oguejiofor, Jordan A. McKean, Kelly M. Herremans, Thomas J. George, Carmen J. Allegra, Steven J. Hughes, Song Han. A triplet therapeutic strategy targeting MEK, BCL-XL, and EGFR, for KRAS-mutant pancreatic ductal adenocarcinoma [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 7223.

Abstract 6959: Acetylcholine potentiates invasion and migration of human pancreatic cancer cells under hypoxia through α7 nAChR-mediated increases in HIF-1α expression

Abstract The most significant nerve-related problem in clinical pancreatic cancer management is perineural invasion (PNI), characterized as the neoplastic invasion of cancer cells into or surrounding the nerves. It is a characteristic feature of pancreatic ductal adenocarcinoma (PDAC) associated with a poor prognosis, tumor recurrence, and emergent pain. However, why PDAC is associated with a higher incidence of PNI remains unclear. HIF-1 (hypoxia-inducible factor-1) regulates the expression of ~1000 genes involved in angiogenesis, metastasis, tumor growth, chemoresistance and radioresistance, underscoring the growing interest in targeting HIF-1 for cancer control. In the present study, we investigated the molecular mechanisms underlying neurotransmitter acetylcholine (Ach)-potentiated HIF-1α expression and subsequent increase in invasion and migration of human pancreatic cancer cells in hypoxia (2% O2). The expression of various acetylcholine receptors in six types of pancreatic cancer cell lines (MIA-PaCa-2, PANC-1, HPAF-II, Capan-1, AsPC-1, and BxPC-3 cells) was observed using qPCR, and α7 nAChRs was observed to be expressed in all pancreatic cancer cells. Therefore, we chose MIA-PaCa-2 cells, expressing high levels of α7 nAChRs, and HPAF-II cells, expressing low levels of α7 nAChRs, for loss- and gain-of-function studies, respectively. In vitro assays showed that, under hypoxic conditions, Ach caused a concentration-dependent increase in α7 nAChRs-mediated HIF-1α expression, enhancing expression of HIF-1α target genes, and promoting invasion and migration of human pancreatic cancer cells. We further found that Ach increased HIF-1α protein stability in pancreatic cancer cells under hypoxic conditions. This effect was mediated by YAP signaling, as evidenced by the fact that Ach-induced increases in HIF-1α protein stability were blocked by siRNA-mediated knockdown of YAP. Consistent with these findings, an investigation of the relationship between α7 nAChRs and clinicopathological features in pancreatic cancer patients using publicly available datasets showed that high levels of α7 nAChRs are correlated with a poorer prognosis in pancreatic cancer patients. Collectively, these findings identify novel mechanisms by which Ach potentiates invasion and migration of pancreatic cancer cells and provide further evidence that HIF-1α is a potential anticancer target in Ach-associated pancreatic cancer. Citation Format: Yunmi Cho, Eun-Taex Oh, Ha Gyeong Kim, Heon Joo Park. Acetylcholine potentiates invasion and migration of human pancreatic cancer cells under hypoxia through α7 nAChR-mediated increases in HIF-1α expression [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 6959.