Pancreatic Cancer Cell Lines Research Articles

DNA replication stress and mitotic catastrophe mediate sotorasib addiction in KRASG12C-mutant cancer

BackgroundSotorasib is the first KRASG12C inhibitor approved by the US Food and Drug Administration for treating KRASG12C-mutant non-small-cell lung cancer (NSCLC). Clinical trials on the therapeutic use of sotorasib for cancer have reported promising results. However, KRASG12C-mutant cancers can acquire resistance to sotorasib after treatment. We incidentally discovered that sotorasib-resistant (SR) cancer cells are addicted to this inhibitor. In this study, we investigated the mechanisms underlying sotorasib addiction.MethodsSotorasib-resistant cells were established using KRASG12C-mutant pancreatic cancer and NSCLC cell lines. Cell viability in the presence or absence of sotorasib and in combination with multiple inhibitors was assessed through proliferation assay and annexin V/propidium iodide (PI) flow cytometry assays. The mechanisms underlying drug addiction were elucidated through 5-bromo-2′-deoxyuridine (BrdU) incorporation assay, immunofluorescence staining, time-lapse microscopy, and comet assay. Furthermore, a subcutaneous xenograft model was used to demonstrate sotorasib addiction in vivo.ResultsIn the absence of sotorasib, the sotorasib-resistant cells underwent p21Waf1/Cip1-mediated cell cycle arrest and caspase-dependent apoptosis. Sotorasib withdrawal resulted in robust activation of mitogen-activated protein kinase (MAPK) pathway, inducing severe DNA damage and replication stress, which activated the DNA damage response (DDR) pathway. Persistent MAPK pathway hyperactivation with DDR exhaustion led to premature mitotic entry and aberrant mitosis, followed by micronucleus and nucleoplasmic bridge formation. Pharmacologic activation of the MAPK pathway with a type I BRAF inhibitor could further enhance the effects of sotorasib withdrawal on sotorasib-resistant cancer cells both in vitro and in vivo.ConclusionsWe elucidated the mechanisms underlying the sotorasib addiction of cancer cells. Sotorasib addiction appears to be mediated through MAPK pathway hyperactivity, DNA damage, replication stress, and mitotic catastrophe. Moreover, we devised a therapeutic strategy involving a type I BRAF inhibitor to strengthen the effects of sotorasib addiction; this strategy may provide clinical benefit for patients with cancer.

The Combination of PD-L1 and CTLA-4 Suppression Significantly Decreased the Expression Levels of Cancer Stem Cell Factors in the Pancreatic Cancer Cell Line

Background: It is thought that a limited number of aberrant cancer stem cells (CSCs), which encourage carcinogenesis, tumor metastasis, and treatment resistance, are the cause of pancreatic cancer, a disease with a high mortality rate. Increasing evidence shows that CSCs use immunosuppressive properties to avoid immune system identification. In Pancreatic cancer, the therapeutic consequences of the relationship between the expression of immune checkpoints such as programmed death receptor ligand-1 (PD-L1) and cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and the presence of CSCs are poorly known. As a result, in the present investigation, we examined how the expression levels of CSCs were affected by PD-L1 and CTLA-4 knockdown using specific siRNA. Methods: Independently and together, PD-L1 and CTLA-4 siRNA were transfected into MIA PaCa-2 cells. RNA extraction and cDNA synthesis were then performed. Finally, using qRT-PCR, the gene expression levels of CSCs markers, including Nanog, CD133, CD44, and Oct-4, in transfected groups were measured. Results: In the MIA PaCa-2 cell line, siRNA-mediated inhibition of PD-L1 and CTLA-4 decreased the expression of CSC factors. Moreover, combined suppression of these two stemness-related immune checkpoints significantly decreased Nanog, CD133, CD44, and Oct-4 expression compared to inhibition of PD-L1 and CTLA-4 separately. Conclusion: Considering that the combination of PD-L1 and CTLA-4 suppression using siRNA significantly decreased the expression levels of CSCs factors, this approach may be regarded as an effective therapy for this cancer.

Remote Activation of Enzyme Nanohybrids for Cancer Prodrug Therapy Controlled by Magnetic Heating.

Herein, we have developed nanohybrids (nHs) to remotely activate a therapeutic enzyme for its use in Directed Enzyme Prodrug Therapy (DEPT). The coencapsulation of magnetic nanoparticles (MNPs) with horseradish peroxidase (HRP) using biomimetic silica as an entrapment matrix was optimized to obtain nanosized hybrids (∼150 nm) for remote activation of the therapeutic enzyme. HRP converts indole-3-acetic acid (3IAA) into peroxylated radicals, whereas MNPs respond to alternating magnetic fields (AMFs) becoming local hotspots. The AMF application triggered an increase in the bioconversion rate of HRP matching the activity displayed at the optimal temperature of the nHs (Topt = 50 °C) without altering the temperature of the reaction media. This showed that enzyme nanoactuation is possible with MNPs even if they are not covalently bound. After an extensive physicochemical/magnetic characterization, the spatial location of each component of the nH was deciphered, and an insulating role of the silica matrix was suggested as critical for introducing remote control over HRP. In vitro assays, using a human pancreatic cancer cell line (MIA PaCa-2), showed that only upon exposure to AMF and in the presence of the prodrug, the enzyme-loaded nHs triggered cell death. Moreover, in vivo experiments showed higher reductions in the tumor volume growth in those animals treated with nHs in the presence of 3IAA when exposed to AMF. Thus, this work demonstrates the feasibility of developing a spatiotemporally controlled DEPT strategy to overcome unwanted off-target effects.

Oleanolic acid increases the anticancer potency of doxorubicin in pancreatic cancer cells.

Combination therapy is a novel cancer therapy approach that combines two or more chemotherapy drugs. This treatment modality enhances the efficacy of chemotherapy by targeting key pathways in an additive or synergistic manner. Therefore, we investigated the efficacy of combination therapy by widely used chemotherapy drug doxorubicin (DOX) and oleanolic acid (OA) to induction of apoptosis for pancreatic cancer (PC) therapy.The effects of DOX, OA, and their combination (DOX-OA) were investigated on proliferation and viability of PC cell line (PANC-1) by MTT assay. Moreover, migration and invasion of the cancer cells were evaluated by trans-well migration assay and wound healing assay. Flow cytometry and DAPI (4',6-diamidino-2-phenylindole) staining were employed to investigate apoptosis quantification and qualification of the treated cancer cells. Finally, mRNA expression of apoptosis-related genes was assessed by quantitative real-time polymerase chain reaction.Our results demonstrated that the proliferation and metastasis potential of PC cells significantly decreased after treatment by DOX, OA, and DOX-OA. Moreover, we observed an increase in apoptosis percentage in the treated cancer cells. The apoptosis-related gene expression was modified to increase the apoptosis rate in all of the treatment groups. However, the anticancer potency of DOX-OA combination was significantly more than that ofDOX and OA treatments alone.Our study suggested that DOX-OA combination exerts more profound anticancer effects against PC cell lines than DOX or OA monotherapy. This approach may increase the efficiency of chemotherapy and reduce unintended side effects by lowering the prescribed dose of DOX.

FBXO28 promotes proliferation, invasion, and metastasis of pancreatic cancer cells through regulation of SMARCC2 ubiquitination.

The E3 ligase F-box only protein 28 (FBXO28) belongs to the F-box family of proteins that play a critical role in tumor development. However, the potential function of FBXO28 in pancreatic cancer (PC) and its molecular mechanism remain unclear. In this study, we examined FBXO28 expression in PC and its biological role and explored the mechanism of FBXO28-mediated proliferation, invasion, and metastasis of PC cells. Compared with paracancerous tissues and human normal pancreatic ductal epithelial cells, FBXO28 was highly expressed in PC tissues and cell lines. High expression of FBXO28 was negatively correlated with the survival prognosis of patients with PC. Functional assays indicated that FBXO28 promoted PC cell proliferation, invasion, and metastasis in vitro and in vivo. Furthermore, immunoprecipitation-mass spectrometry was used to identify SMARCC2 as the target of FBXO28; upregulation of SMARCC2 can reverse the effect of overexpression of FBXO28 on promoting the proliferation, invasion, and metastasis of PC cells. Mechanistically, FBXO28 inhibited SMARCC2 expression in post-translation by increasing SMARCC2 ubiquitination and protein degradation. In conclusion, FBXO28 has a potential role in PC, possibly promoting PC progression through SMARCC2 ubiquitination. Thus, FBXO28 might be a potential treatment target in PC.

Quantitative analysis of contribution of mild and moderate hyperthermia to thermal ablation and sensitization of irreversible electroporation of pancreatic cancer cells

IntroductionIrreversible electroporation (IRE) is an ablation modality that applies short, high-voltage electric pulses to unresectable cancers. Although considered a non-thermal technique, temperatures do increase during IRE. This temperature rise sensitizes tumor cells for electroporation as well as inducing partial direct thermal ablation. Aim: To evaluate the extent to which mild and moderate hyperthermia enhance electroporation effects, and to establish and validate in a pilot study cell viability models (CVM) as function of both electroporation parameters and temperature in a relevant pancreatic cancer cell line. MethodsSeveral IRE-protocols were applied at different well-controlled temperature levels (37 °C ≤ T ≤ 46 °C) to evaluate temperature dependent cell viability at enhanced temperatures in comparison to cell viability at T = 37 °C. A realistic sigmoid CVM function was used based on thermal damage probability with Arrhenius Equation and cumulative equivalent minutes at 43 °C (CEM43°C) as arguments, and fitted to the experimental data using “Non-linear-least-squares”-analysis. ResultsMild (40 °C) and moderate (46 °C) hyperthermic temperatures boosted cell ablation with up to 30% and 95%, respectively, mainly around the IRE threshold Eth,50% electric-field strength that results in 50% cell viability. The CVM was successfully fitted to the experimental data. ConclusionBoth mild- and moderate hyperthermia significantly boost the electroporation effect at electric-field strengths neighboring Eth,50%. Inclusion of temperature in the newly developed CVM correctly predicted both temperature-dependent cell viability and thermal ablation for pancreatic cancer cells exposed to a relevant range of electric-field strengths/pulse parameters and mild moderate hyperthermic temperatures.

Combination effects of amino acid transporter LAT1 inhibitor nanvuranlat and cytotoxic anticancer drug gemcitabine on pancreatic and biliary tract cancer cells

BackgroundCytotoxic anticancer drugs widely used in cancer chemotherapy have some limitations, such as the development of side effects and drug resistance. Furthermore, monotherapy is often less effective against heterogeneous cancer tissues. Combination therapies of cytotoxic anticancer drugs with molecularly targeted drugs have been pursued to solve such fundamental problems. Nanvuranlat (JPH203 or KYT-0353), an inhibitor for L-type amino acid transporter 1 (LAT1; SLC7A5), has novel mechanisms of action to suppress the cancer cell proliferation and tumor growth by inhibiting the transport of large neutral amino acids into cancer cells. This study investigated the potential of the combined use of nanvuranlat and cytotoxic anticancer drugs.MethodsThe combination effects of cytotoxic anticancer drugs and nanvuranlat on cell growth were examined by a water-soluble tetrazolium salt assay in two-dimensional cultures of pancreatic and biliary tract cancer cell lines. To elucidate the pharmacological mechanisms underlying the combination of gemcitabine and nanvuranlat, we investigated apoptotic cell death and cell cycle by flow cytometry. The phosphorylation levels of amino acid-related signaling pathways were analyzed by Western blot. Furthermore, growth inhibition was examined in cancer cell spheroids.ResultsAll the tested seven types of cytotoxic anticancer drugs combined with nanvuranlat significantly inhibited the cell growth of pancreatic cancer MIA PaCa-2 cells compared to their single treatment. Among them, the combined effects of gemcitabine and nanvuranlat were relatively high and confirmed in multiple pancreatic and biliary tract cell lines in two-dimensional cultures. The growth inhibitory effects were suggested to be additive but not synergistic under the tested conditions. Gemcitabine generally induced cell cycle arrest at the S phase and apoptotic cell death, while nanvuranlat induced cell cycle arrest at the G0/G1 phase and affected amino acid-related mTORC1 and GAAC signaling pathways. In combination, each anticancer drug basically exerted its own pharmacological activities, although gemcitabine more strongly influenced the cell cycle than nanvuranlat. The combination effects of growth inhibition were also verified in cancer cell spheroids.ConclusionsOur study demonstrates the potential of first-in-class LAT1 inhibitor nanvuranlat as a concomitant drug with cytotoxic anticancer drugs, especially gemcitabine, on pancreatic and biliary tract cancers.

Hsa_circ_0014784-induced YAP1 promoted the progression of pancreatic cancer by sponging miR-214-3p

ABSTRACT Background Pancreatic cancer (PC) is one of the most common gastrointestinal tumors globally. Former investigations discovered that circular RNAs (circRNAs) play an important role in PC development. circRNAs belong to a new class of endogenous noncoding RNAs, which have been found to mediate the progression of diverse types of tumors. Nevertheless, the roles of circRNAs and the underlying regulatory mechanisms in PC remain unknown. Methods In this study, our team employed next-generation sequencing (NGS) to examine the abnormal circRNA expression in PC tissues. The circRNA expression in PC cell lines and tissues was detected. Then, regulatory mechanism and targets were examined with bioinformatics analysis, luciferase reporting analysis, Transwell migration, 5-ethynyl−2′-deoxyuridine, and CCK−8 analysis. An in vivo experiment was employed to elucidate hsa_circ_0014784 roles in PC tumor growth and metastasis. Results The results showcased abnormal circRNA expression in PC tissues. Our lab also found that hsa_circ_0014784 expression incremented in PC tissues and cell lines, implying that hsa_circ_0014784 functioned in PC progression. hsa_circ_0014784 downregulation inhibited PC proliferation and invasion in vivo and in vitro. The bioinformatics and luciferase report data validated that both miR−214-3p and YAP1 were hsa_circ_0014784 binding partners. The overexpression of YAP1 reversed the migration, proliferation, and epithelial – mesenchymal transition (EMT) of PC cells and the angiogenic differentiation of HUVECs after miR−214-3p overexpression. Conclusion Taken together, our study found that hsa_circ_0014784 downregulation decremented invasion, proliferation, EMT, and angiogenesis of PC by regulating miR−214-3p/YAP1 signaling.

Anoikis-Related Gene Signature for Prognostication of Pancreatic Adenocarcinoma: A Multi-Omics Exploration and Verification Study

Anoikis, a form of apoptosis that occurs due to detachment of cells from the extracellular matrix, has been linked to the development of cancer in several studies. However, its role in pancreatic cancer remains incompletely understood. In this study, we utilized univariate Cox regression and LASSO regression analyses to establish a prognostic model for pancreatic adenocarcinoma based on anoikis-related genes in the TCGA database. Additionally, we performed univariate and multifactorial Cox analyses of protein expression results for TCGA pancreatic adenocarcinoma. We further explored the difference in immune infiltration between the high-risk and low-risk groups and verified the expression of the screened genes using quantitative real-time PCR (qRT-PCR). Our findings indicate that numerous anoikis-related genes are linked to pancreatic adenocarcinoma prognosis. We identified seven prognostic genes (MET, DYNLL2, CDK1, TNFSF10, PIP5K1C, MSLN, GKN1) and validated that their related proteins, such as EGFR and MMP2, have a significant impact on the prognosis of pancreatic adenocarcinoma. Based on clustering analyses of the seven prognostic genes, patients could be classified into three distinct categories, for which somatic mutations varied significantly across the groups. High-risk and low-risk groups also exhibited significant differences in immune infiltration. All genes were found to be highly expressed in pancreatic cancer cell lines (ASPC-1, CFPAC-1) as compared to a normal pancreatic cell line (HPDE). Based on the seven anoikis-related genes, we formulated a robust prognostic model with high predictive accuracy. We also identified the significant impact of KRAS, P53, and CDKN2A mutations on the prognosis of this fatal disease. Therefore, our study highlights the crucial role of anoikis in the development of the pancreatic adenocarcinoma tumor microenvironment.

Cytotoxic and anti-metastatic action mediates the anti-proliferative activity of Rhazya stricta Decne inducing apoptotic cell death in human cancer cells: Implication in chemopreventive mechanism

Cancer is associated with a high rate of pre-mature mortality worldwide and serves as a significant impediment to extended life expectancy, leading to undesirable long-term effects on the quality of life of the patients. Bioactive chemical products derived from natural sources have an important place in the well-being of the human population since ancient times. Compounds derived from natural sources have dominated the drug discovery programs in the last five decades and comprise a substantial proportion of current-day pharmaceutical agents. Rhazya stricta, an evergreen shrub, it belongs to family Apocynaceae of order Gentianales, and the Rhazya stricta is known to have certain medicinal properties, as the Middle East and South Asian traditional medicine employed this plant as a cure for different diseases. Herein, the hydro-methanolic extract of Rhazya stricta Decne has been studied for its effect on spectrum of cancer cells, including LNCaP, C4-2B, PC-3 prostate cancer cells, MDA-MB-231, MCF-7, SKBR3 breast cancer cells, A-549 lung cancer cells and BxPC-3, MiaPaCa-2 pancreatic cancer. Hydro-methanolic extract of Rhazya stricta Decne in a dose-dependent manner, showed progressive inhibition of cell growth by induction of cell death in the treated human cancer cells. The IC value range for different breast cancer cell lines was 142-178 µg/ml; for prostate cancer cell lines, it was 90-148 µg/ml; for pancreatic cancer cell lines 116-166 µg/ml and for the lung cancer cells, it was reported to be 180 µg/ml. The anti-metastatic potential of extract was indicated by the notable reduction in invasiveness and cell migration. Moreover, the structurally diverse phytochemical rich extract, also downregulates the signaling of NF-kB and the NF-kB downstream target cytokine VEGF, providing an insight into the anticancer action mechanism.Keywords: Cell biology; Cancer chemoprevention; Anticancer drugs; Cell signaling; Natural compounds

Transcriptomic and functional analysis of ANGPTL4 overexpression in pancreatic cancer nominates targets that reverse chemoresistance

BackgroundPancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers based on five-year survival rates. Genes contributing to chemoresistance represent novel therapeutic targets that can improve treatment response. Increased expression of ANGPTL4 in tumors correlates with poor outcomes in pancreatic cancer.MethodsWe used statistical analysis of publicly available gene expression data (TCGA-PAAD) to test whether expression of ANGPTL4 and its downstream targets, ITGB4 and APOL1, were correlated with patient survival. We measured the impact of ANGPTL4 overexpression in a common pancreatic cancer cell line, MIA PaCa-2 cells, using CRISPRa for overexpression and DsiRNA for knockdown. We characterized global gene expression changes associated with high levels of ANGPTL4 and response to gemcitabine treatment using RNA-sequencing. Gemcitabine dose response curves were calculated on modified cell lines by measuring cell viability with CellTiter-Glo (Promega). Impacts on cell migration were measured using a time course scratch assay.ResultsWe show that ANGPTL4 overexpression leads to in vitro resistance to gemcitabine and reduced survival times in patients. Overexpression of ANGPTL4 induces transcriptional signatures of tumor invasion and metastasis, proliferation and differentiation, and inhibition of apoptosis. Analyses revealed an overlapping signature of genes associated with both ANGPTL4 activation and gemcitabine response. Increased expression of the genes in this signature in patient PDAC tissues was significantly associated with shorter patient survival. We identified 42 genes that were both co-regulated with ANGPTL4 and were responsive to gemcitabine treatment. ITGB4 and APOL1 were among these genes. Knockdown of either of these genes in cell lines overexpressing ANGPTL4 reversed the observed gemcitabine resistance and inhibited cellular migration associated with epithelial to mesenchymal transition (EMT) and ANGPTL4 overexpression.ConclusionsThese data suggest that ANGPTL4 promotes EMT and regulates the genes APOL1 and ITGB4. Importantly, we show that inhibition of both targets reverses chemoresistance and decreases migratory potential. Our findings have revealed a novel pathway regulating tumor response to treatment and suggest relevant therapeutic targets in pancreatic cancer.

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities.

Six new compounds, including a tetralone 1, two xanthones 2 and 3, a flavan derivative 4, and two nor-diterpenoids 7 and 8, accompanied by two known flavan derivatives 5 and 6 and a known olefine acid (9) were isolated from whole bodies of Kronopolites svenhedini (Verhoeff). The structures of the new compounds were determined by 1D and 2D nuclear magnetic resonance (NMR) and other spectroscopic methods, as well as computational methods. Selected compounds were evaluated for their biological properties against a mouse pancreatic cancer cell line and inhibitory effects on iNOS and COX-2 in RAW264.7 cells.

Rutin Inhibits Hepatic and Pancreatic Cancer Cell Proliferation by Inhibiting CYP3A4 and GST

Abstract: Background: Digestive cancer is among the major causes of mortality and morbidity worldwide. Rutin, a bioactive secondary metabolite belonging to flavonoids and distributed in many fruits and vegetables has shown anti-proliferative, anti-cancer, and neuroprotective activities. In this study, the antiproliferative, antioxidant and apoptotic activities of rutin on hepatic and pancreatic cancer cell lines were investigated. Materials and Methods: The effect on cellular viability was monitored by SRB assay. Increasing activity of caspases (3/7) was used as an indicator of apoptosis. Additionally, the anti-inflammatory and antioxidant activities of rutin were evaluated after measuring amount of prostaglandin E2 (PGE2) produced and through DPPH free radical scavenging assays, respectively. Moreover, the inhibitory effect on both CYP3A4 and GST enzymes has also been evaluated. Results: According to the data presented here, rutin has anti-proliferative effect and raises the number of caspases 3/7 in investigated cell lines. Conclusion: HepG-2 cells showed the highest cellular growth inhibition, followed by BxPC-3, Huh-7, MiaPaCa-2, Suit-2, and the normal cell line HPDE. Rutin also inhibited the cyctochrome P450 enzyme (CYP450 3A4) and glutatihione-S-transferase activity, with dose-dependent inhibition. Furthermore, suppression of PGE2 synthesis in BxPC-3 cells supported rutin's anti-inflammatory action (high COX-2 expression). Keywords: Rutin, Pancreatic and Liver cancer, Apoptosis and Anti-inflammatory, Antioxidant.

Devil's club Falcarinol inhibits human glioblastoma cell proliferation and tumor progression in xenografts

BackgroundEffective treatment for human glioblastoma is lacking and a novel effective therapeutic agent is urgently needed. It is known that falcarinol-type polyacetylenes (FC-type PAs) are bioactive ingredients in ginseng and other plants from the Araliaceae family. Our earlier study showed that polyacetylene Falcarinol (FC), 1,2-dihydrofalcarinol (FCH) and 3-acetoxyfalcarinol (FCA) are potent proliferation inhibitors of human pancreatic ductal cancer cell lines. MethodsIn this study we evaluated the bioactivities of these synthetic FC-type polyacetylenes (FC-type PAs) on human glioblastoma DBTRG-05MG cell line with cell viability, cell proliferation, cell migration, wound healing and clonogenic assays. We further evaluated synthetic FC on inhibition of DBTRG tumor bearing NOD-Prkdcem26Il2rgem26/Nju (NCG) mice. ResultsFC dose dependently shifted DBTRG-05MG cells toward apoptosis as well as necrosis. FC and FCA, but not FCH, at near IC50 concentration inhibited colony formation in a 3-week clonogenic assay. Twice weekly intra-peritoneal injection of FC at 10 mg/kg significantly reduced tumor growth and tumor size compared to untreated control animals. ConclusionsSynthetic FC inhibits human glioblastoma cancer cell proliferation in vitro and in vivo. The availability of synthetic FC and other FC-type PAs in sufficient quantity and consistent quality would facilitate and expedite further research leading to potential clinical applications.

Combination of 5-FU plus KRAS G12D inhibitor MRTX1133 against human colorectal and pancreatic cancer cells and the affects on inhibition of pERK and immune-stimulatory cytokine patterns in in KRAS G12D and KRAS G12V tumor cells.

e16301 Background: Colorectal cancer (CRC) & pancreatic cancer are among deadliest cancers with great disease burden. The most commonly mutated oncogenic alteration in human cancers is KRAS, which is prevalent in pancreatic, colorectal malignancies. KRAS is considered an especially difficult, if not "undruggable" target. The KRAS G12D is present in more than 40% of PDAC & 34.2% of CRC cases. KRAS mutation subtypes are associated with different downstream pathways and varied clinical outcomes in cancer. MRTX1133 has been identified as a noncovalent, potent, and selective inhibitor of KRASG12D which has been shown to suppress KRASG12D signaling in cells and in vivo. We hypothesized that combination of MRTX1133 with 5-FU will be more effective at slowing or stopping tumor growth, and prolonging overall survival time for patients while allowing lower dose 5-FU with less side effects. Methods: We investigated synergistic effects on pERK inhibition and changes in immune tumor killing with 5-FU plus KRAS G12D inhibitor MRTX1133 in pancreatic and colon cancer cell lines. Human CRC (N=6) and pancreatic (N=4) cancer cell lines with different KRAS mutations were used in experiments evaluating drug effects on pERK at 6 and 24 hours. We evaluated changes at 48 hours in cytokine profiles in treated cells using a custom panel of 62 cytokines, chemokines, and growth factors associated with tumor growth, immune stimulation or immune suppression. Results: Colorectal and pancreatic cancer cell lines had IC50 sensitivities ranging from 7 to 12 microM 5-FU, and >100 nM to >5 microM for MRTX1133 (G12D N=4: LS513, 120 nM; HPAF-II, 1.8 microM; SNUC2B, 5.7 microM; PANC-1, 2.8 microM). For non-G12D, the range of IC50 for MRTX1133 was in the range of 2 to 9 microM for CRC lines with G12V, G13D, or wild- type KRAS (N=7). Synergies between 5-FU and MRTX1133 were observed regardless of presence of KRAS G12D mutation with combination indices of <0.5 indicating strong synergy. pERK was suppressed by MRTX1133 treatment of tumor cells regardless of KRAS G12D mutation. IL8/CXCL8, MICA, Angiopoietin 2, VEGF and TNF-alpha were reduced while IL-18/IL-1F4 increased. Conclusions: Our studies reveal strong synergy between MRTX1133 & 5-FU in human pancreatic & colon cancer models at much lower than IC50 dosage which is important for avoiding side effects. This is the first description that effect of KRAS G12D inhibitor MRTX1133 is active on KRAS G12V. The surprising synergy in KRAS G12V samples with combination therapy and the important synergistic change in cytokine patterns suggests potential strong immune stimulatory anti-cancer effects of MRTX1133 & 5FU against mCRC and pancreatic cancer cells regardless of KRAS G12D mutation which should be considered when including patients with respective mutations in clinical trials.

Prognostic evaluation of pancreatic cancer based on the model of chemo-radiotherapy resistance-related genes.

The incidence and mortality of pancreatic cancer are almost the same, and the 5-year survival rate is less than 10%. The high mortality of pancreatic cancer is related to chemo-radiotherapy. The present study aimed to establish a prognostic signature of pancreatic cancer based on chemo-radiotherapy resistant-related genes (CRRGs). In this study, we explored the radiation-resistant and chemotherapy-resistant pancreatic cancer cell lines by colony formation and a subcutaneous tumor model in nude mice. Next, we obtained CRRGs from radiation- and gemcitabine-resistant pancreatic cancer cell lines in the Gene Expression Omnibus (GEO) database. Based on univariate Cox and least absolute shrinkage and selection operator (LASSO) Cox regression analyses, a prognostic model of the pancreatic adenocarcinoma (PAAD) cohort in The Cancer Genome Atlas (TCGA) database (N=177) was established and verified using the GEO cohort data set (N=112). Finally, the functions of candidate target genes were verified by a methyl thiazolyl tetrazolium (MTT) assay, a colony formation assay, and a subcutaneous tumor model in nude mice. Through the in vitro and in vivo experiments, we found that radiotherapy- and chemotherapy-resistant pancreatic cancer cells were cross-resistant to chemotherapy and radiotherapy. We constructed a risk model consisting of nine CRRGs (SNAP25, GPR87, DLL1, LAD1, WASF3, ARHGAP29, ZBED2, GAD1, and JAG1) by using public databases. According to the Kaplan-Meier curve analysis, the survival of the high-risk group was worse than that of the low-risk group. We then used nomograms to predict the 1/3/5-year overall survival (OS) in pancreatic cancer patients. We chose JAG1 as a candidate target since it has been proven to be involved in the stemness maintenance of cancer cells, and found that JAG1 silencing inhibited the proliferation and chemo-radiotherapy tolerance of pancreatic cancer cells. This study established and validated a prognostic signature of pancreatic cancer using nine CRRGs. The in vitro and in vivo experiments showed that JAG1 could promote the proliferation and chemoradiotherapy tolerance of pancreatic cancer cell lines. These findings may offer new insights into the role of CRRGs in pancreatic cancer and provide novel prognostic biomarkers for the treatment of pancreatic cancer.

Phase 3 PANOVA-3 study: Tumor treating fields (TTFields) therapy concomitant with gemcitabine and nab-paclitaxel (GnP) for front-line treatment of locally advanced pancreatic cancer.

TPS4199 Background: Tumor Treating Fields (TTFields) therapy is a locoregional antimitotic treatment approved for newly diagnosed and recurrent glioblastoma GBM and pleural mesothelioma. TTFields (150 kHz) therapy, with/without chemotherapy, had antiproliferative and anticlonogenic activity in pancreatic cancer cell lines, and reduced tumor volume and weight more than chemotherapy alone in in vivo models. TTFields therapy with gemcitabine and nab-paclitaxel (GnP) was well-tolerated, with promising efficacy in metastatic and locally advanced pancreatic adenocarcinoma (LAPC) in the phase 2 PANOVA study (NCT01971281). LAPC prognosis remains poor despite available therapies, which can negatively impact quality of life (QoL). As such, there remains a need for effective and tolerable treatments. Methods: PANOVA-3 (EF-27, NCT03377491) is a prospective, randomized, phase 3 study investigating the efficacy and safety of TTFields therapy with GnP in patients with LAPC, with a planned enrollment of 556 patients. Key inclusion criteria are: a diagnosis of unresectable LAPC (per NCCN guidelines), ECOG PS of 0–2, and no prior treatment. Patients will be stratified by performance status and geographical region and assigned 1:1 to treatment groups to receive TTFields therapy + GnP or GnP alone. GnP will be administered at a standard dose per standard of care. TTFields therapy (150 kHz, 18h/day) will be delivered by the NovoTTF-200T System until local disease progression per RECIST v1.1. Usage will be tracked by the device. Follow-up will be performed every 4 weeks and computed tomography scans of the chest and abdomen will be taken every 8 weeks until disease progression. Patients will be followed every month until death. The primary endpoint is overall survival and key secondary endpoints include QoL, pain-free survival, and puncture-free survival, which will be compared between treatment groups. Other secondary endpoints include progression-free survival (PFS), local PFS, objective response rate, 1-year survival rate, rate of resectability, and safety. Guidance around usage, lifestyle integration and prevention and management of skin adverse events will be provided by Device Support Specialists and field personnel. Usage information will be provided to patients and physicians to facilitate discussions to optimize outcomes by maximizing time on therapy. Together, these novel support approaches aim to optimize patient usage and outcomes. The trial is currently recruiting at 149 sites, globally. The DMC last reviewed the trial in August 2022, and suggested that the trial continue as planned. Clinical trial information: NCT03377491 .

Impact of novel pan-RAS inhibitors on efficacy and resistance to AMG-510 and MRTX-1133 in pancreatic cancer cell lines.

4155 Background: Mutant-activated RAS genes are the most frequently mutated gene family associated with cancer (almost 30% of all cancers contain a mutant RAS gene). KRAS is the predominant isoform mutated in cancer and is the isoform exclusively mutated in pancreatic ductal carcinoma (PDAC). Since almost all PDAC cases harbor a mutant RAS, it is arguably the most RAS-addicted tumor type. There is now considerable evidence implicating mutant KRAS as a driver of PDAC. Recently, several mutant KRAS-targeted therapies (sotorasib and adagrasib) have been developed and show promise in PDAC patients. We have developed a direct inhibitor of RAS with a predicted unique interaction region capable of directly binding to wild-type H- and K-RAS, but which shows preferential binding for KRAS G12D and G12C mutants. This novel inhibitor disrupts the RAS effector domain and blocks the ability of RAS to signal through its effectors. Methods: We used in silico virtual library screening to identify an initial candidate inhibitor which was effective at inhibiting the 3D growth of PDAC cells without affecting their growth in 2D. Subsequent iterative rounds of medicinal chemistry was then performed to identify a series of derivatives with enhanced activity, as determined by 3D growth inhibition assays and effects on Ras signaling, as determined by Western blot analysis of phosphor-ERK, phosphor-Akt and activation of Ral A. Results: Our series of RAS inhibitors effectively block PDAC cell growth in 3D without impacting their 2D proliferation and suppress the interaction of KRAS with its effector cRAF. The inhibitors also effectively inhibit RAS signaling in mutant RAS containing PDAC cells. Since our novel compounds are predicted to bind to RAS at a different site to either AMG-510 (G12C specific inhibitor) and MRTX-1133 (G12D specific inhibitor), we tested the co-operativity of our compounds with these existing agents. Our compounds enhanced the anti-proliferative effects of both MRTX-113 and AMG-510 in mutant KRAS G12D and G12C PDAC cells, respectively. Conclusions: We have developed a series of novel RAS inhibitors that directly bind preferentially to mutant KRAS that may serve as new mutant KRAS-targeted therapeutics, and that may also have the potential to enhance the efficacy or suppress the resistance of AMG-510 and MRTX-1133.

Gemcitabine‑fucoxanthin combination in human pancreatic cancer cells.

Gemcitabine is a chemotherapeutic agent for pancreatic cancer treatment. It has also been demonstrated to inhibit human pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. The aim of the present study was to investigate the suppressive effect of fucoxanthin, a marine carotenoid, in combination with gemcitabine on pancreatic cancer cells. MTT assays and cell cycle analysis using flow cytometry were performed to study the mechanism of action. The results revealed that combining a low dose of fucoxanthin with gemcitabine enhanced the cell viability of human embryonic kidney cells, 293, while a high dose of fucoxanthin enhanced the inhibitory effect of gemcitabine on the cell viability of this cell line. In addition, the enhanced effect of fucoxanthin on the inhibitory effect of gemcitabine on PANC-1 cells was significant (P<0.01). Fucoxanthin combined with gemcitabine also exerted significant enhancement of the anti-proliferation effect in MIA PaCa-2 cells in a concentration dependent manner (P<0.05), compared with gemcitabine treatment alone. In conclusion, fucoxanthin improved the cytotoxicity of gemcitabine on human pancreatic cancer cells at concentrations that were not cytotoxic to non-cancer cells. Thus, fucoxanthin has the potential to be used as an adjunct in pancreatic cancer treatment.

Betulinic acid, a major therapeutic triterpene of Celastrus orbiculatus Thunb., acts as a chemosensitizer of gemcitabine by promoting Chk1 degradation.

Celastrus orbiculatus Thunb., also called as oriental bittersweet vine or climbing spindle berry, a traditional Chinese herbal medicine has been used to treat a spectrum of painful and inflammatory diseases for centuries. Explored for their unique medicinal properties, C.orbiculatus offers additional therapeutic effects on cancerous diseases. The effect of single-agent gemcitabine on survival has not long been encouraging, combination therapies provide patients multiple chances of benefit for improved clinical response. This study aims at expounding the chemopotentiating effects and underlying mechanisms of betulinic acid, a primary therapeutic triterpene of C. orbiculatus in combination with gemcitabine chemotherapy. The preparation of betulinic acid was optimized using ultrasonic-assisted extraction method. Gemcitabine-resistant cell model was established by induction of the cytidine deaminase. MTT, colony formation, EdU incorporation and Annexin V/PI staining assays were used to evaluate cytotoxicity, cell proliferation and apoptosis in BxPC-3 pancreatic cancer cell line and H1299 non-small cell lung carcinoma cell line. Comet assay, metaphase chromosome spread and γH2AX immunostaining were applied for DNA damage assessment. Western blot and co-immunoprecipitation was used to detect the phosphorylation and ubiquitination of Chk1. Mode of action of gemcitabine in combination with betulinic acid was further captured in BxPC-3-derived mouse xenograft model. We noticed that the extraction method had an impact on the thermal stability of C. orbiculatus. Ultrasound-assisted extraction at room temperature in shorter processing time could maximize the overall yields and biological activities of C. orbiculatus. The major constituent was identified as betulinic acid, and the pentacyclic triterpene represented the prominent anticancer activity of C. orbiculatus. Forced expression of cytidine deaminase conferred acquired resistance to gemcitabine, while betulinic acid displayed equivalent cytotoxicity toward gemcitabine-resistant and sensitive cells. A combination therapy of gemcitabine with betulinic acid produced synergistic pharmacologic interaction on cell viability, apoptosis and DNA double-strand breaks. Moreover, betulinic acid abrogated gemcitabine-triggered Chk1 activation by destabilizing Chk1 loading via proteasomal degradation. The combination of gemcitabine and betulinic acid significantly retarded BxPC-3 tumor growth in vivo compared to single-agent gemcitabine treatment alone, accompanied with reduced Chk1 expression. These data provide evidence that betulinic acid is a potential candidate for chemosensitization as a naturally occurring Chk1 inhibitor and warrants further preclinical evaluation.