Pancreatic Cancer Cell Lines Research Articles

Abstract 390: A comparison of the activity of the quadruplex-targeting experimental drugs QN-302 and CX-5461 (pidnarulex) in wild-type and gemcitabine-resistant pancreatic cancer cell lines

Abstract The compound QN-302, a tetra-substituted naphthalene diimide (ND) derivative has been designed as a potent compound for targeting quadruplex sequences in cancer genes. It has single-digit nM anti-proliferative activity in a panel of human pancreatic cancer (PDAC) cell lines (Ahmed et al., ACS Med Chem Lett, 2020, 11, 1634-1644). It also has significant anti-tumor activity in xenograft, orthotopic and genetic (KPC) models for PDAC. Its mode of action involves the targeting of quadruplex (G4)-forming sites in promoter regions of cancer-associated genes, where their prevalence is over-represented compared to other genes. The structurally unrelated compound CX-5461 has also been reported to be a G4-binding agent, with selective activity in BRCA1/2 deficient cells and tumors (Xu and Hurley, Bioorg Med Chem Lett. 2022; Xu et al., Nat Commun, 2017). It is currently in early-stage clinical trials in breast and other solid cancers with deficiencies in DNA repair (Hilton et al., Nat Commun. 2022). We have previously reported that a precursor to QN-302, the tri-substituted naphthalene diimide compound CM03, is highly active in both wild-type and gemcitabine-resistant PDAC cell lines (Ahmed et al, Sci Rep, 2020). This is explained by the finding using whole-genome transcriptome analysis that the CM03-sensitive genes are largely unaffected in the resistant lines. We now report that the clinical candidate compound QN-302, which is 10-fold more potent than CM03, retains its potency in both MIA-PACA2 and PANC-1 PDAC cell lines with >1000-fold increase in gemcitabine resistance. This is also the case for CX-5461, although this compound is 50-100 times less potent, with GI50 values of 83-95 nM in cell proliferation assays treated for 96 h. Gemcitabine either alone or in combination is still a mainstay of current PDAC treatment. Resistance to gemcitabine is common and is a major contributor to the poor outcomes for most PDAC patients. The ability of QN-302 to retain activity in chemo-resistant PDAC cell lines suggests that it will offer significant advantage in the clinic over gemcitabine-based therapies. QN-302 is bio-available at therapeutic doses and is well tolerated at these levels in animal models. It is being developed for clinical evaluation by Qualigen Therapeutics Inc and is currently at the pre-IND stage. Citation Format: Ahmed Ahmed, Tariq Arshad, Stephen Neidle. A comparison of the activity of the quadruplex-targeting experimental drugs QN-302 and CX-5461 (pidnarulex) in wild-type and gemcitabine-resistant pancreatic cancer cell lines [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 390.

Abstract 5173: BET inhibition reprograms pancreatic cancer associated fibroblasts to promote anti-tumor immunity

Abstract BACKGROUND: Pancreatic ductal adenocarcinoma (PDAC) is the most malignant neoplasm of the pancreas, and is refractory to most therapeutic strategies, including immunotherapy. We have previously demonstrated that loss of CDKN2A in PDAC tumor cells promotes an immunologically-cold tumor microenvironment, which can be counteracted through the use of bromodomain and extraterminal domain inhibitors (BETi). The immunosuppressive PDAC tumor microenvironment is also characterized by a dense desmoplastic stroma, rich in cancer associated fibroblasts (CAFs). These CAFs are a highly plastic population of cells, comprised of myofibroblastic, inflammatory, and antigen-presenting CAFs (myCAFs, iCAFs, and apCAFs, respectively). Previously research has suggested BETi can alter the function of CAFs, suggesting this therapeutic strategy may be effective at targeting both the tumor and stromal compartments of PDAC. Here we hypothesize that BETi enhances anti-tumor immunity in CDKN2A-deficient PDAC by modulating the phenotype and function of PDAC CAFs. METHODS: Isogenic wild-type and CDKN2A-deficient KPCluc pancreatic cancer cell lines were used in conjunction with KPCluc-derived murine CAF cells. CAF spheroids were used to evaluate the effects of BETi on CAF phenotype (as measured by flow cytometry) and function (as measured by NanoString analysis, checkpoint ligand expression by flow cytometry, and T cell migration assays). Additionally, the impact of BETi-induced modulation of CAF phenotype and function on wild-type and CDKN2A-deficient tumor cell spheroids was measured by flow cytometry. RESULTS: Treatment of pancreatic CAFs with BETi induced expression of genes associated with DNA damage responses and type I IFN expression. Additionally, while CAF supernatants suppressed T cell migration in vitro, treatment with BETi restored T cell migration across a transwell. This was due in part to DNA damage/STING/NF-κB signaling induced in PDAC CAF following BETi. Supernatants from BETi-treated PDAC CAFs were found to modulate PD-L1 expression on PDAC tumor cells. Direct treatment of CAFs with BETi induced a dramatic dose- and time-dependent polarization of CAF spheroids towards a myCAF phenotype. However, while BETi induced DNA damage/STING/NF-κB signaling in CAF cells, this signaling did not contribute towards this myCAF polarization, as treatment of CAF spheroids with BETi and STING or NF-κB inhibitors did not impact myCAF polarization. Additional mechanisms of polarization are currently being evaluated and will be updated at presentation. CONCLUSIONS: BET inhibition modulates CAF cell phenotype and function to promote anti-tumor immune responses. Taken together with the impact of BET inhibition on CDKN2A-deficient PDAC tumor cells, these data suggest BETi is a rational treatment approach to promote anti-tumor immunity in this genetically defined immunotherapy resistant patient population. Citation Format: Trisha Minocha, Alison Thomas, Brian M. Olson. BET inhibition reprograms pancreatic cancer associated fibroblasts to promote anti-tumor immunity. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5173.

Abstract 2025: Phosphoproteomic profiling following MAP3K1 kinase inhibition identifies NPM1 as a novel substrate

Abstract In response to diverse cellular cues, MAP3K1, a mitogen-activated protein kinase, participates in various cancer signaling networks including the NFκB, JNK, ERK, and p38 pathways. Functioning as a signaling kinase in these oncogenic pathways, MAP3K1 contributes to tumor growth and metastasis, thus making it an attractive therapeutic target for cancer. Structure-guided design using MAP3K1 AlphaFold and Schrödinger GLIDE led to the development of 51-106, a selective MAP3K1 small molecule inhibitor. Profiling using the KiNativTM platform in a cellular matrix revealed 51-106 as a selective ATP-competitive MAP3K1 inhibitor. 51-106 blocked TNFα-induced MAP3K1-IKKβ-mediated NFκB activity. Phosphoproteomics analysis following MAP3K1 inhibition by 51-106 showed a dose dependent decrease in NPM1 T199 phosphorylation indicating NPM1 as a novel substrate of MAP3K1. NPM1 plays a critical role in DNA damage repair; consistently we observed a dose dependent S-phase arrest upon MAP3K1 inhibition by 51-106, suggesting a dysfunctional DNA damage response. Higher MAP3K1 transcript level in pancreatic cancer patients is associated with poorer (50% vs. 15%) 5-year survival. Treatment of pancreatic cancer cell lines with the MAP3K1 inhibitor 51-106 inhibited cell growth and migration. In combination studies, 51-106 synergistically inhibited growth with gemcitabine in LSL-KrasG12D/+, LSL-Trp53R172H/+, Pdx1-Cre (KPC) cell lines in vitro and in KPC syngeneic orthotopic implantation mouse model of pancreatic cancer in vivo. Our study is the first to identify NPM1 as a potential substrate of MAP3K1, and these results warrant the investigation of MAP3K1 inhibition as a therapeutic option in cancer. Citation Format: Lidia Boghean, Sarbjit Singh, Kiran Mangalaparthi, Surendra K. Shukla, Smitha Kizhake, Amritha Kizhake, Donn Wishka, Jayapal Reddy Mallareddy, Joel Morris, Paul Grothaus, Pankaj K. Singh, Akhilesh Pandey, Amarnath Natarajan. Phosphoproteomic profiling following MAP3K1 kinase inhibition identifies NPM1 as a novel substrate [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2025.

Abstract 2642: BL-B01D1, a novel EGFR×HER3-targeting ADC, demonstrates robust anti-tumor efficacy in preclinical evaluation

Abstract EGFR and HER3, members of the human epidermal growth factor receptor (ErbB) family, are targeted in cancer therapy due to their over-expression and pathway dependence in common human epithelial carcinoma tumors. To develop a promising therapeutic anti-tumor agent, we generated BL-B01D1, an EGFR×HER3-targeting ADC, which can bind to EGFR and/or HER3 positive cells and is expected to be superior to anti-EGFR and anti-HER3 ADCs. It is comprised of a bispecific antibody against EGFR/HER3 (SI-B001), a cathepsin B cleavable linker, and a novel topoisomerase I inhibitor agent (Ed-04), which is a derivative of the alkaloid camptothecin, driving cell cycle arrest at the S phase and subsequent apoptosis. BL-B01D1 achieves a high drug-to-antibody-ratio (DAR=8) with a highly stable linker. The pharmacological potential of this ADC was evaluated in comparison to its parental single antigen-targeting ADCs in xenograft models composed of either the human colorectal cancer cell line SW620 or pancreatic cancer cell line BxPC3. The tumor inhibition activity of BL-B01D1 was compared with ADCs prepared from each parental anti-EGFR or anti-HER3 mAb conjugated with the same linker and payload. The bispecific ADC, BL-B01D1 exhibited stronger tumor inhibition capacity than the anti-EGFR ADC and the anti-HER3 ADC separately. The preclinical studies suggest BL-B01D1, as an EGFR×HER3-targeting ADC, might be a promising novel agent with activity toward a broad range of human cancers. The clinical phase I has been progressing and the available data exhibit excellent efficacy but low levels of targeted toxicity in the non-small cell lung cancer (NSCLC) treatment setting. Overall, these data suggest BL-B01D1 has potential to serve as a novel, efficacious therapeutic agent for NSCLC with similar therapeutic impact as DS-8201 has in breast cancer treatment. Citation Format: Weili Wan, Shuwen Zhao, Shi Zhuo, Yong Zhang, Lan Chen, Gangrui Li, Blair Renshaw, Jahan Salar Khalili, Sa Xiao, Yi Zhu. BL-B01D1, a novel EGFR×HER3-targeting ADC, demonstrates robust anti-tumor efficacy in preclinical evaluation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2642.

Abstract 6217: Inhibiting ataxia-telangiectasia mutated and RAD3-related (ATR) by BAY 1895344 overcomes chemoresistance to oxaliplatin and promotes synergistic anti-tumor effect in pancreatic cancer

Abstract Pancreatic Ductal Adenocarcinoma (PDAC) is a highly aggressive disease with a poor prognosis and a limited response to most of the treatments. Despite a platinum-based drug such as oxaliplatin or cisplatin is one of the most effective chemotherapy drugs for PDAC, resistance to it is a major limiting factor in PDAC treatment, indicating an urgent need for new approaches. Recently, targeting major DNA damage response (DDR) regulators such as ATM (Ataxia-telangiectasia mutated) or ATR (Ataxia telangiectasia mutated and Rad3-related) kinase has shown therapeutic potential in cancer treatment. This shows that it may be possible to enhance the responsiveness of platinum medicines via a DDR inhibition strategy. The most recently developed ATR inhibitor with the greatest potency, BAY 1895344, showed an anti-proliferative effect in clinical trials. Here, we aimed to evaluate the effect of ATR inhibition using BAY 1895344 on responsiveness to oxaliplatin in pancreatic cancer, for the first time. CFPAC-1 and Capan-2 are selected among six kinds of pancreatic cancer cell lines as oxaliplatin-sensitive and -resistant cells, respectively. According to BRAID analysis, combining the BAY 1895344 and oxaliplatin resulted in strong synergistic effects in both cell lines, particularly in Capan-2. The synergism is also confirmed in all four organoids derived from PDAC patients. We found that p-Chk1, coordinating DDR and cell cycle checkpoint, was considerably suppressed by the combined treatments, which was associated with elevated γ-H2AX intensity, cell cycle arrest and apoptosis. Moreover, we investigated the in vivo synergistic anti-tumor efficacy of combination therapy using a tumor-bearing nude mice model with CFPAC-1 and Capan-2 cells, demonstrating a substantial reduction of tumor growth in combination therapy when compared to single treatment. In conclusion, ATR inhibition enhanced the anticancer effect of oxaliplatin, and this combined therapeutic strategy may be effective in overcoming chemo-resistance in PDAC. (This study is supported by National Cancer Center, Republic of Korea (No. 2212470, 2010330)) Citation Format: Hye Won Shon, Jung Won Chun, Jeong Eun Gong, Mi Rim Lee, Yu-Sun Lee, Sumin Kang, Sunshin Kim, Sang Myung Woo, In Rae Cho, Woo Hyun Paik, Woo Jin Lee, Ji Kon Ryu, Yong-Tae Kim, Sang Hyub Lee, Yun-Hee Kim. Inhibiting ataxia-telangiectasia mutated and RAD3-related (ATR) by BAY 1895344 overcomes chemoresistance to oxaliplatin and promotes synergistic anti-tumor effect in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6217.

Abstract 2238: RAS activity-related features of metastatic pancreatic cancer

Abstract Background: RAS activity might play crucial roles in the aggravation of KRAS-mutated pancreatic cancer (PC), including systemic inflammatory reactions, tumor-driven inflammation, chemo-refractoriness and anorexia. We aimed to identify RAS activity-related features in PC patients with liver metastasis (LM), to create a murine xenograft model of human PC cells representative of RAS-driven aggravation. Methods: RAS activities in 77 patients who underwent needle biopsy for LM of treatment-naïve PC were measured using an RAS signature score from a comprehensive cDNA microarray dataset of LM samples. Changes in the sum of the longest diameter of the target lesion in the first month of chemotherapy (ΔSLD), laboratory data and anorexia score at baseline were evaluated. Gene modules to be correlated with RAS activity and aggravation were evaluated using weighted co-expression network analysis (WGCNA). Human PC cells were classified as high and low activity according to in silico analysis of the DepMap CCLE expression dataset for profiling RAS activity and the best hub gene expression in the gene module. Subcutaneous xenograft models of human PC cells with high and low activity in severe combined immunodeficiency mice were compared to explore the RAS-related phenotype. Results: KRAS-mutated LM was detected in 70 of the 77 PC patients (90.9%). RAS signatures were up-regulated in patients with KRAS-mutated LM (P < 0.01), high serum level of C-reactive protein (P = 0.01) as a systemic inflammatory marker, high expression of IL-6 mRNA by the tumor (P = 0.12) as an index of tumor-driven inflammation, and high level of phospho-Erk (P = 0.03). In 58 PC patients receiving first-line chemotherapy for KRAS-mutated LM, ΔSLD in patients with a high RAS signature was increased as compared to those in patients with a low RAS signature (P = 0.045). WGCNA methods revealed that the green module highly correlated with RAS activity and aggravation. Based on in silico analysis with classification of the human PC cell lines CFPAC-1 and SUIT-2 into high and low activity cells, respectively, CFPAC-1 tumors showed desmoplasia and high expression of tumor IL-6 and liver SAA1 as compared to SUIT-2 tumors (P = 0.046 and P = 0.016, respectively). Conclusions: Tumor RAS activity is related to inflammation-related aggravation in PC patients. RAS-related inflammation can be accurately presented in a murine model of human PC cells, which might be an effective tool to test the inhibition of RAS-driven inflammation. Citation Format: Shuichi Mitsunaga, Mari Masuda, Hiroki Yoshimatsu, Yoichi Kamei, Mitsuhito Sasaki, Kazuo Watanabe, Masafumi Ikeda. RAS activity-related features of metastatic pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2238.

E3 Ubiquitin Ligase MARCH8 Promotes Pancreatic Cancer Growth and Metastasis by Activating STAT3 via Degradation of PTPN4.

The role E3 ubiquitin ligase membrane-associated RING-CH 8 (MARCH8) has not been studied in pancreatic cancer. Pancreatic cancer cell lines and the normal pancreatic cells were tested in vitro studies and male athymic nude mice were tested in vivo studies. Measuring cell viability by Cell Counting Kit-8 assay (CCK8), 5-ethynyl-2'- deoxyuridine (Edu) staining, and colony formation assay. Wound healing assay was implemented for cell migration and Transwell assay was performed for cell invasion to evaluate the histological status by hematoxylin and eosin staining and to detect the protein ubiquitination by ubiquitination assay. The protein expression was determined by immunohistochemistry staining and western blotting, and mRNA expression was measured by quantitative reverse transcription polymerase chain reaction. The expression of MARCH8 was increased whereas PTPN4 was decreased in pancreatic cancer cells. Overexpression of MARCH8 promoted the growth, migration, and invasion of cells, and knockdown of PTPN4 had the similar effects both in vitro and in vivo. MARCH8 promoted PTPN4 protein degradation through ubiquitination. Moreover, PTPN4 suppressed the transcription activities of STAT3 by impairing the level of pSTAT3 (705), while inhibition of PTPN4 activated phosphorylation of STAT3. MARCH8 promoted pancreatic cancer growth and invasion through mediating the degradation of PTPN4 and activated the phosphorylation of STAT3.

Correlation of gene expression profiles to identify pancreatic cancer cell lines that best model primary human tumors.

Cancer cell lines are important research models for studying tumor biology in vivo. The accuracy of such studies is highly dependent on the phenotypic and genetic similarity of cell lines to patient tumors, but this is not always the case, particularly for pancreatic cancer. We compared the gene expression profiles of various pancreatic cancer cell lines and primary human pancreatic tumor tissues to determine which pancreatic cancer cell line best models human primary tumor. Profiles of messenger RNA (mRNA) expression of 33 pancreatic cancer cell lines and 892 patient samples of pancreatic adenocarcinoma (PAAD) were obtained from the Gene Expression Omnibus (GEO) database. Microarray data were normalized using the robust multichip average (RMA) algorithm and batch effect removal was performed using ComBat. The pooled data of each PAAD cell line were compared to patient tumors based on the top 2,000 genes with largest interquartile range (IQR), 134 gene-collections of cancer-related pathways, and 504 gene-collections of cancer-related functions using pairwise Pearson's correlation analysis. PAAD cell lines were poorly correlated with patient tumor tissues based on the top 2,000 genes. Up to 50% of cancer-related pathways were not strongly recommended in PAAD cell lines, and a small proportion of cancer-related functions (12-17%) were poorly correlated with PAAD cell lines. In pan-pathway analysis, the cell lines showing the highest genetic correlation to patient tumors were Panc 03.27 for PAAD cell lines from a primary lesion site and CFPAC-1 for PAAD cell lines from a metastatic lesion site. In pan-function analysis, the cell lines showing the highest genetic correlation to patient tumors were Panc 03.27 for PAAD cell lines from a primary lesion site and Capan-1 for PAAD cell lines from a metastatic lesion site. The gene expression profiles of PAAD cell lines correlate weakly with those of primary pancreatic tumors. Through comparison of the genetic similarity between PAAD cell lines and human tumor tissue, we have provided a strategy for choosing the appropriate PAAD cell line.

Cytotoxic Responses of Pancreatic Cancer Cell Line to Bitter Leaf (Vernonia Amygdalina), Tomato (Solanum Lycopersicum) and Coconut (Cocos Nucifera) Milk Extracts

This work is primarily designed to determine, through cell lines, the cytotoxic responses of pancreatic cancer cell (PANC-1) to reconstituted lyophilized extracts of coconut milk, bitter leaf and tomato with a view of evaluating the anticancer properties of these extract. The cytotoxicity analysis was performed on the extracts using the MTT assay method as previously described on pancreatic tumour (PANC-1) cell lines . The cytotoxicity studies showed concentration and dose-dependent decrease in cell viability of pancreatic cancer cell line (PANC-1) to the three lyophilized extracts of coconut milk, bitter leaf and tomato. Bitter leaf aqueous extract was significantly the most cytotoxic to the cancer cells followed by coconut and lastly tomato extracts. The cytotoxicity of coconut milk compared with tomato and bitter leaf to PANC-1 increased in the order of bitter leaf > coconut milk > tomato.

CircACTR2 attenuates gemcitabine chemoresiatance in pancreatic cancer through PTEN mediated PI3K/AKT signaling pathway

BackgroundRecently, accumulating studies have unveiled that circRNAs exert critical function in a variety of tumor biological processes including chemoresistance. Our previous study has found circACTR2 is significantly down-regulated in acquired gemcitabine (GEM)- resistant pancreatic cancer (PC) cells, which has not been well-explored. Our study aimed to research the function and molecular mechanism of circACTR2 in PC chemoresistance.MethodsqRT-PCR and western blot analysis was performed to detect gene expression. The effect of circACTR2 on PC GEM resistance were examined by CCK-8 and flow cytometry assays. Whether circACTR2 could sponge miR-221-3p and regulate PTEN expression were determined by bioinformatics analysis, RNA pull-down, and Dual-luciferase reporter assay.ResultscircACTR2 was notably down-regulated in a panel of GEM-resistant PC cells lines, and negatively associated with aggressive phenotype and poor prognosis of PC. circACTR2 downregulation contributed to GEM chemoresistance of PC cells with decreased S phase ratio of cell cycle and cell apoptosis, as confirmed by gain- and loss-of-function assays in vitro. In addition, circACTR2 overexpression retarded GEM resistance in vivo. Further, circACTR2 acted as a ceRNA against miR-221-3p, which directly targeted PTEN. The mechanistic studies revealed that loss of circACTR2 promoted GEM resistance in PC through activating the PI3K/AKT signaling pathway by downregulating PTEN expression in a miR-221-3p dependent manner.ConclusionscircACTR2 reversed the chemoresistance of PC cells to GEM through inhibiting PI3K/AKT signaling pathway by sponging miR-221-3p and upregulating PTEN expression.

The impact of cellular senescence and senescence‑associated secretory phenotype in cancer‑associated fibroblasts on the malignancy of pancreatic cancer.

Cancer‑associated fibroblasts (CAFs) are implicated in the strong malignancy of pancreatic cancer (PC). Various CAF subtypes have different functions, and their heterogeneity likely influence the malignancy of PC. Meanwhile, it is known that senescent cells can create a tumor‑promoting microenvironment by inducing a senescence‑associated secretory phenotype (SASP). In the present study, the effects of individual differences in CAFs on PC malignancy were investigated with a focus on cellular senescence. First, primary cultures of CAFs from 8 PC patients were generated and co‑cultured with PC cell lines. This co‑culture assay showed that differences in CAFs induce differences in PC cell proliferation. It was further investigated which clinical factors affected the malignant potential of CAF and it was found that the difference of malignant potential of each CAF was marginally related to the age of original patients. Next, to verify the senescence of CAFs really affected the malignant potential of CAF, PCR array analysis of each CAF sample was performed and it was revealed that expression of genes about cellular senescence and SASP such as tumor protein p53, nuclear factor kappa B subunit 1, and IL6, are related to the malignant potential of CAFs impacting on PC proliferation. Finally, to elucidate the effect of p53‑mediated cellular senescence of CAFs on malignant potential of PC, it was examined whether CAFs with the treatment of p53 inhibitor affected PC cell proliferation in co‑culture assays. The treatment of CAFs with p53 inhibitor significantly suppressed PC cell proliferation. In addition, a comparison of the concentration of IL‑6, a SASP cytokine, in the co‑culture supernatant showed a significant decrease in the sample after p53 inhibitor treatment. In conclusion, the present results suggested that proliferation potential of PC may be related to p53‑mediated cellular senescence and SASP of CAFs.

Long noncoding RNA CASC9 promotes pancreatic cancer progression by acting as a ceRNA of miR‐497‐5p to upregulate expression of CCND1

Pancreatic cancer (PC) is an aggressive malignancy with poor prognosis. Accumulating studies have showed that long non-coding RNA (lncRNA) is a crucial regulator in various tumorigenesis and progression including PC. This research aims to explore the roles and molecular mechanism of lncRNA cancer susceptibility candidate 9 (CASC9) in PC. The expression levels of lncRNA CASC9 and miR-497-5p were evaluated in PC tissues and paired adjacent healthy tissues by quantitative real-time PCR. PC cell lines were transfected with lentivirus targeting lncRNA CASC9, and cells proliferation, migration and invasion tests were conducted. Dual luciferase reporter assays were also carried out to explore the relationship between lncRNA CASC9, miR-497-5p and Cyclin D1 (CCND1). LncRNA CASC9 was significantly up-regulated in PC tissues, while miR-497-5p expression was down-regulated. Down-regulation of lncRNA CASC9 in PC cells can significantly suppress the cell aggressiveness both in vitro and in vivo; moreover, knock-down of miR-497-5p could neutralize this impact. Additionally, the luciferase activity assay has assured that CCND1 was a downstream target of miR-497-5p. LncRNA CASC9 can promote the PC progression by modulating miR-497-5p/CCND1 axis, which is potential target for PC treatment.

Targeting mitochondrial transcription factor A sensitizes pancreatic cancer cell to gemcitabine

BackgroundThe survival of pancreatic cancer cells, particularly cancer stem cells which are responsible for tumor relapse, depends on mitochondrial function. Mitochondrial transcription factor A (TFAM) is critical for the regulation of mitochondrial DNA and thus mitochondrial function. However, the possible involvement of TFAM in pancreatic cancer is unknown. MethodsHuman samples were obtained from pancreatic cancers and their adjacent tissues; human pancreatic cell lines were cultured in RPMI1640 medium. TFAM expressions in pancreatic tissues and cultured cells were determined using immunohistochemistry, ELISA, and reverse transcription polymerase chain reaction (RT-PCR). The effect of TFAM on cell growth, migration, colony formation and apoptosis were evaluated. Mitochondrial biogenesis in pancreatic cancer and normal cells were examined. ResultsThe majority of pancreatic cancer tissues exhibited higher TFAM expression compared to the adjacent counterparts. Consistently, TFAM mRNA and protein levels were higher in pancreatic cancer cell lines than in immortalized normal pancreatic epithelial cells. There was no difference on TFAM level between gemcitabine-sensitive and resistant pancreatic cancer cells. Functional analysis demonstrated that TFAM overexpression activated pancreatic normal and tumor cells whereas TFAM inhibition effectively inhibited the growth of pancreatic cancer cells. TFAM inhibition enhanced gemcitabine's cytotoxicity and suppressed growth, anchorage-independent colony formation and survival of gemcitabine-resistant pancreatic cancer cells. Mechanistic studies showed that TFAM inhibition resulted in remarkable mitochondrial dysfunction and energy crisis followed by oxidative stress. The basal mitochondrial biogenesis level correlated well with TFAM level in pancreatic cancer cells. ConclusionsTFAM played essential roles in pancreatic cancer via regulating mitochondrial functions which highlighted the therapeutic value of inhibiting TFAM to overcome gemcitabine resistance.

Palladium‐Catalysed C−C Bond Forming 4‐Cyanophenyl‐nicotinamide Conjugates; Anti‐Pancreatic Cancer Screening on Capan‐1 Cell Line

AbstractPancreatic cancer is the most severe, as a consequence of asymptomatic nature and ineffective therapies among all malignancies. Nicotinamides are effective ring systems in the treatment of pancreatic cancer with their wide range of applications. In the present investigation, nicotinamide and 4‐cyanophenyl ring systems are brought together to obtain greater potency. For the process of investigation, PARP1 protein is targeted and evaluated by docking at the active site to determine the protein‐ligand interaction, revealed the potential with the binding affinity of −9.0 to −11.0 Kcal/mol to inhibit the poly ADP‐ribose polymerase 1 (PARP1) pathway. The MTT‐assay assessment of a synthesized series has been performed against Capan‐1 pancreatic cancer cell line. The nicotinamide compounds demonstrated a significant inhibitory effect over Capan‐1 cell line, and 6‐(4‐cyanophenyl)‐N‐(3‐phenylpropyl)nicotinamide exhibited as a potential lead for the development of novel chemotherapeutics against pancreatic cancer.

Nicolaioidesin C: An Antiausterity Agent Shows Promising Antitumor Activity in a Pancreatic Cancer Xenograft Mouse Model.

Human pancreatic tumors are hypovascular in nature, and their tumor microenvironment is often characterized by hypoxia and severe nutrient deprivation due to uncontrolled heterogeneous growth, a phenomenon known as "austerity". However, pancreatic tumor cells have the inherent ability to adapt and thrive even in such low nutrient and hypoxic microenvironments. Anticancer drugs such as gemcitabine and paclitaxel, which target rapidly proliferating cells, are often ineffective against nutrient-deprived pancreatic cancer cells. In order to overcome this limitation, the search for novel agents that can eliminate cancer cells' adaptations to nutrition starvation, also known as "antiausterity" agents, represents a promising strategy to make the cancer cells susceptible to treatment. The natural product (+)-nicolaioidesin C (Nic-C) was found to have potent antiausterity activity against the PANC-1 human pancreatic cancer cell line in a nutrient-deprived condition. However, its efficacy in vivo remained untested. To address this, we synthesized Nic-C in its racemic form and evaluated its antitumor potential in a human pancreatic cancer xenograft model. Nic-C inhibited pancreatic cancer cell migration and colony formation and significantly inhibited tumor growth in MIA PaCa-2 xenografts in a dose-dependent manner. Furthermore, Nic-C inhibited the Akt/mTOR and autophagy signaling pathways in both in vitro and in vivo studies. Metabolomic profiling of in vivo tumor samples suggests that Nic-C downregulates amino acid metabolism while upregulating sphingolipid metabolism.

Small Nuclear RNA 64 (snoRNA64): A novel Tumor Biomarker for Pancreatic Cancer

The pancreatic ductal adenocarcinoma (PDAC), which represents over 90% of pancreatic cancer cases, has the highest proliferative and metastatic rate in comparison to other pancreatic cancer compartments. This study is designed to determine whether small nucleolar RNA, H/ACA box 64 (snoRNA64) is associated with pancreatic cancer initiation and progression. Gene expression data from the Gene Expression Omnibus (GEO) repository have shown that snoRNA64 expression is reduced in primary and metastatic pancreatic cancer as compared to normal tissues based on statistical analysis of the in Silico analysis. Using qPCR techniques, pancreatic cancer cell lines include PK-1, PK-8, PK-4, and Mia PaCa-2 with different levels of snoRNA64, including PK-1, PK-8, PK-4, and Mia PaCa-2. The level of expression is correlated with the cell line epithelial or mesenchymal characteristics. Cell lines displaying epithelial characteristics such as PK-1, PK-8 show high levels of snoRNA64 meanwhile, cell lines displaying mesenchymal characteristics such as PK-4, Mia PaCa-2 show low levels of snoRNA64. The level of expression is correlated with the cell line epithelial or mesenchymal characteristics. After knocking down the PK-8 with high snoRNA64 expression, the epithelial markers E. cadherin (E-cad) and Cytokeratin-8 (CK-8) are decreased, while mesenchymal markers Vimentin (Vim), Cytokeratin-19 (CK-19), Metalloprotease -2 (MMP-2), and Metalloprotease-3 (MMP-3) are activated. Those changes suggest that PK-8 responding to the snoRNA64 knock down protocol and increase in mesenchymal function. Together, snoRNA64 expression may participate in epithelial to mesenchymal transition (EMT) and mesenchymal to epithelial transition (MET), in which during metastasis these processes are crucial. In addition, snoRNA64 may be considered as a potential diagnostic biomarker for both early and invasive stages of PDAC. And due to its gradual expression decreases, it may be considered a barrier in tumor progression.

Methanolic fraction of Cassia fistula L. bark exhibits potential to combat oxidative stress and possess antiproliferative activity

ABSTRACT Cassia fistula L. is well known for its traditional medicinal properties as an anti-inflammatory, hepatoprotective, antifungal, antibacterial, antimutagenic, and wound healing agent. The aim of the present study was to determine antioxidant, genoprotective, and cytotoxic potential of different fractions of C. fistula bark including hexane (CaMH), chloroform (CaMC), ethyl acetate (CaME), and methanol (CaMM). Among all the fractions studied, CaMM exhibited maximal radical scavenging activity in antioxidant DPPH assay, Superoxide anion radical scavenging assay and nitric oxide radical scavenging assay displayed an IC50 value of 18.95, 29.41, and 13.38 µg/ml, respectively. CaMM fraction possessed the highest phenolic (130.37 mg gallic acid equivalent/g dry weight of extract) and flavonoid (36.96 mg rutin equivalent/g dry weight of fraction) content. Data demonstrated significant positive correlation between polyphenol levels and radical scavenging activity. Single cell gel electrophoresis (Comet assay) exhibited genoprotective potential of C. fistula bark fractions against DNA damage induced by hydrogen peroxide (H2O2) in human lymphocytes. CaMM fraction displayed highest protective ability against H2O2 induced-toxicity as evidenced by significant decrease in % tail DNA content from 30 to 7% at highest concentration (200 µg/ml). CaMM was found to be rich in catechin, gallic acid, chlorogenic acid, and kaempferol. The phenolic content and antioxidant ability of the fractions was markedly negatively correlated with H2O2- induced DNA damage in human lymphocytes. Cytotoxic potential was evaluated against dermal epidermoid carcinoma (A431), pancreatic (MIA PaCa-2) and brain glioblastoma (LN-18) cancer cell lines using MTT assay. Results showed that C. fistula bark fractions possessed highest toxicity against the skin carcinoma cells. CaMM fraction reduced over 50% cell growth at the concentration of 76.72 µg/ml in A431 cells. These findings suggest that fractions of C. fistula bark exhibit potential to be considered as therapeutic agents in various carcinomas.

Anticancer Activity of Sunitinib Analogues in Human Pancreatic Cancer Cell Cultures under Normoxia and Hypoxia

Pancreatic cancer remains one of the deadliest cancer types. It is usually characterized by high resistance to chemotherapy. However, cancer-targeted drugs, such as sunitinib, recently have shown beneficial effects in pancreatic in vitro and in vivo models. Therefore, we chose to study a series of sunitinib derivatives developed by us, that were proven to be promising compounds for cancer treatment. The aim of our research was to evaluate the anticancer activity of sunitinib derivatives in human pancreatic cancer cell lines MIA PaCa-2 and PANC-1 under normoxia and hypoxia. The effect on cell viability was determined by the MTT assay. The compound effect on cell colony formation and growth was established by clonogenic assay and the activity on cell migration was estimated using a 'wound healing' assay. Six out of 17 tested compounds at 1 µM after 72 h of incubation reduced cell viability by 90% and were more active than sunitinib. Compounds for more detailed experiments were chosen based on their activity and selectivity towards cancer cells compared to fibroblasts. The most promising compound EMAC4001 was 24 and 35 times more active than sunitinib against MIA PaCa-2 cells, and 36 to 47 times more active against the PANC-1 cell line in normoxia and hypoxia. It also inhibited MIA PaCa-2 and PANC-1 cell colony formation. Four tested compounds inhibited MIA PaCa-2 and PANC-1 cell migration under hypoxia, but none was more active than sunitinib. In conclusion, sunitinib derivatives possess anticancer activity in human pancreatic adenocarcinoma MIA PaCa-2 and PANC-1 cell lines, and they are promising for further research.

Effective anticancer agents based-on two Pillar[5]arene derivatives for pancreas cancer cell lines: synthesis, apoptotic effect, caspase pathway.

This study aimed to evaluate the possible anticancer effects of two different pillar[5]arene derivatives (5Q-[P5] and 10Q-P[5]) on two different pancreatic cancer cell lines in vitro. For this purpose, changes in the expression of major genes that play a role in apoptosis and caspase pathways were investigated. Panc-1 and BxPC-3 cell lines were used in the study and the cytotoxic dose of pillar[5]arenes was determined by the MTT method. Changes in gene expression after pillar[5]arenes treatment were evaluated by real-time polymerase chain reaction (qPCR). Apoptosis was studied by flow cytometry. As a result of analysis, it was determined that proapoptotic genes and genes involved in major caspase activation were upregulated and antiapoptotic genes were down-regulated in Panc-1 cell line treated with pillar[5]arenes. Flow cytometric apoptosis analysis also showed an increased apoptosis rate in this cell line. On the contrary, although MTT analysis showed cytotoxic effect in BxPC-3 cell line treated with two pillar[5]arene derivatives, the apoptosis pathway was not active. This suggested that it may activate different death pathways for BxPC-3 cell line. Thus, it was first determined that the pillar[5]arene derivatives reduced cancer cell proliferation on pancreatic cancer cells.

The SIX1/LDHA Axis Promotes Lactate Accumulation and Leads to NK Cell Dysfunction in Pancreatic Cancer.

Pancreatic cancer (PC) is a malignant cancer with poor prognosis and high mortality rate. Sine oculis homeobox homolog 1 (SIX1) participates in the development of many cancers. However, the function of SIX1 in PC is not fully understood. SIX1 expression was determined using immunohistochemistry in PC tissues and cell lines. Glucose consumption, lactate production, and ATP assays were used to detect the function of SIX1. PC cells and NK cells were cocultured to study the effect of SIX1 overexpression in PC cells on NK cell function. Chromatin immunoprecipitation (ChIP) assays were used to study the relationship between SIX1 and lactate dehydrogenase A (LDHA). A series of in vitro and in vivo assays were further applied to elucidate the important role of the SIX1/LDHA axis in metabolism and NK cell dysfunction in PC. SIX1 was significantly upregulated in PC tissue; SIX1 overexpression promoted the glycolysis capacity of PANC-1 and CFPAC-1 cells and resulted in NK cell dysfunction after the NK cells had been cultured with PC cells. LDHA inhibitor partially restored the promotion of PC caused by SIX1 overexpression. According to ChIP assays, SIX1 directly binds to the LDHA promoter region. Moreover, LDHA inhibitor and lactate transporter blocker treatment promoted the function of NK cells cocultured with PC cells. In vivo experiments yielded the same results. The SIX1/LDHA axis promotes lactate accumulation and leads to NK cell dysfunction in PC.