Signaling Pathways In Pancreatic Cancer Research Articles

Prognostic and therapeutic value of the Eph/Ephrin signaling pathway in pancreatic cancer explored based on bioinformatics

Pancreatic cancer (PC) is one of the most common malignant tumors of the digestive tract and has a very high mortality rate worldwide. Different PC patients may respond differently to therapy and develop therapeutic resistance due to the complexity and variety of the tumor microenvironment. The Eph/ephrin signaling pathway is extensively involved in tumor-related biological functions. However, the key function of the Eph/ephrin signaling pathway in PC has not been fully elucidated. We first explored a pan-cancer overview of Eph/ephrin signaling pathway genes (EPGs). Then we grouped the PC patients into 3 subgroups based on EPG expression levels. Significantly different prognoses and tumor immune microenvironments between different subtypes further validate Eph/ephrin's important role in the pathophysiology of PC. Additionally, we estimated the IC50 values for several commonly used molecularly targeted drugs used to treat PC in the three clusters, which could help patients receive a more personalized treatment plan. Following a progressive screening of optimal genes, we established a prognostic signature and validated it in internal and external test sets. The receiver operating characteristic (ROC) curves of our model exhibited great predictive performance. Meanwhile, we further validated the results through qRT-PCR and immunohistochemistry. Overall, this research provides fresh clues on the prognosis and therapy of PC as well as the theoretical groundwork for future Eph/ephrin signaling pathway research.

Identification of gemcitabine resistance-related AHNAK2 gene associated with prognosis and immune infiltration in pancreatic cancer

PurposeGemcitabine is a basic chemotherapy drug for pancreatic cancer (PC), but resistance is common and causes tumor recurrence and metastasis. Therefore, it is significant to explore gemcitabine resistance-related molecules for individualized treatment and prognosis assessment of PC. MethodsIn this study, transcriptome sequencing and TCGA database analysis were performed, and a differentiated gene AHNAK2 was screened. MEXPRESS database, tissue microarray analysis, and CIBERSORT and TIMER databases were used to correlate AHNAK2 expression with clinicopathological features and prognosis and immune infiltration of PC. Enrichment analysis was used to investigate the significant biological processes associated with AHNAK2. ResultsAHNAK2 was highly expressed in gemcitabine-resistant cells. High expression of AHNAK2 increased the risk of poor overall survival (OS) and progression-free survival (PFS) in PC. Clinicopathologic analysis revealed that AHNAK2 correlated with KRAS, TP53 mutations, histologic type, short OS, N stage, and elevated CA199 levels in PC. Knockdown of AHNAK2 inhibited the ability of cell proliferation and colony formation and enhanced the toxic effect of gemcitabine in PC. Meanwhile, the knockdown of AHNAK2 expression enhanced cell-ECM adhesion, inhibited cell-cell adhesion, and downregulated the KRAS/p53 signaling pathway in PC. Furthermore, AHNAK2 was correlated with immune infiltration, especially B cells and macrophages. ConclusionsOur study unveils for the first time the pivotal role of AHNAK2 in PC, particularly its association with gemcitabine resistance, clinical prognosis, and immune infiltration. AHNAK2 not only drives the proliferation and drug resistance of PC cells by potentially activating the KRAS/p53 pathway but also significantly impacts cell-cell and cell- ECM adhesion. Additionally, AHNAK2 plays a crucial role in modulating the tumor immune microenvironment. These insights underscore AHNAK2's unique potential as a novel therapeutic target for overcoming gemcitabine resistance, offering new perspectives for PC treatment strategies.

Retraction: "Downregulation of long noncoding RNA SNHG1 inhibits cell proliferation, metastasis, and invasion by suppressing the Notch-1 signaling pathway in pancreatic cancer".

Retraction: "Downregulation of long noncoding RNA SNHG1 inhibits cell proliferation, metastasis, and invasion by suppressing the Notch-1 signaling pathway in pancreatic cancer" by Long Cui, Yadong Dong, Xiaochuan Wang, Xin Zhao, Chenchen Kong, Yangsui Liu, Xinchun Jiang, Xinhui Zhang, J Cell Biochem 2019, 120: 6106-6112. The above article, published online on 5 December 2018 in Wiley Online Library (https://onlinelibrary.wiley.com/doi/10.1002/jcb.27897) has been retracted by agreement between the authors, the journal's Editor in Chief, Christian Behl, and Wiley Periodicals LLC. The retraction has been agreed upon authors' request due to concerns related to the data presented in the article. The authors admitted several mistakes during figure compilation resulting in flaws and inconsistencies between results presented and experimental methods described. Thus, the conclusions of this article are considered invalid.

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

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

XYA-2: a marine-derived compound targeting apoptosis and multiple signaling pathways in pancreatic cancer.

Pancreatic cancer is a highly aggressive and fatal disease with limited treatment options and poor prognosis for patients. This study aimed to investigate the impact of XYA-2 {N-(3,7-dimethyl-2,6-octadienyl)-2-aza-2-deoxychaetoviridin A}, a nitrogenated azaphilon previously reported from a deep-sea-derived fungus on the progression of pancreatic cancer cells. The inhibitory effects of XYA-2 on cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion were assessed using various assays. The CCK-8 assay, clone formation assay, flow cytometry assay, wound healing assay, and transwell assay were employed to evaluate cell proliferation, clonogenic potential, cell cycle progression, apoptosis, migration, and invasion, respectively. Moreover, we employed RNA-seq and bioinformatics analyses to uncover the underlying mechanism by which XYA-2 influences pancreatic cancer cells. The revealed mechanism was subsequently validated through qRT-PCR. Our results demonstrated that XYA-2 dose-dependently inhibited the proliferation of pancreatic cancer cells and induced cell cycle arrest and apoptosis. Additionally, XYA-2 exerted a significant inhibitory effect on the invasion and migration of cancer cells. Moreover, XYA-2 was found to regulate the expression of genes involved in multiple cancer-related pathways based on our RNA-seq and bioinformatics analysis. These findings highlight the potential of XYA-2 as a promising therapeutic option for the treatment of pancreatic cancer.

MST2 methylation by PRMT5 inhibits Hippo signaling and promotes pancreatic cancer progression.

The Hippo signaling axis is a tumor suppressor pathway that is activated by various extra-pathway factors to regulate cell differentiation and organ development. Recent studies have reported that autophosphorylation of the core kinase cassette stimulates activation of the Hippo signaling cascade. Here, we demonstrate that protein arginine methyltransferase 5 (PRMT5) contributes to inactivation of the Hippo signaling pathway in pancreatic cancer. We show that the Hippo pathway initiator serine/threonine kinase 3 (STK3, also known as MST2) of Hippo signaling pathway can be symmetrically di-methylated by PRMT5 at arginine-461 (R461) and arginine-467 (R467) in its SARAH domain. Methylation suppresses MST2 autophosphorylation and kinase activity by blocking its homodimerization, thereby inactivating Hippo signaling pathway in pancreatic cancer. Moreover, we also show that the specific PRMT5 inhibitor GSK3326595 re-activates the dysregulated Hippo signaling pathway and inhibits the growth of human pancreatic cancer xenografts in immunodeficient mice, thus suggesting potential clinical application of PRMT5 inhibitors in pancreatic cancer.

Identification of novel curcumin derivatives against pancreatic cancer: a comprehensive approach integrating 3D-QSAR pharmacophore modeling, virtual screening, and molecular dynamics simulations

Pancreatic cancer, known as the “silent killer,” poses a daunting challenge in cancer therapy. The dysregulation of the PI3Kα signaling pathway in pancreatic cancer has attracted considerable interest as a promising target for therapeutic intervention. In this regard, the use of curcumin derivatives as inhibitors of PI3Kα has emerged, providing a novel and promising avenue for developing effective treatments for this devastating disease. Computational approaches were employed to explore this potential and investigate 58 curcumin derivatives with cytotoxic activity against the Panc-1 cell line. Our approach involved ligand-based pharmacophore modeling and atom-based 3D-QSAR analysis. The resulting QSAR model derived from the best-fitted pharmacophore hypothesis (AAHRR_1) demonstrated remarkable performance with high correlation coefficients (R2) of 0.990 for the training set and 0.977 for the test set. The cross-validation coefficient (Q2) of 0.971 also validated the model’s predictive power. Tropsha’s recommended criteria, including the Y-randomization test, were employed to ensure its reliability. Furthermore, an enrichment study was conducted to evaluate the model’s performance in identifying active compounds. AAHRR_1 was used to screen a curated PubChem database of curcumin-related compounds. Two molecules (CID156189304 and CID154728220) exhibited promising pharmacokinetic properties and higher docking scores than Alpelisib, warranting further investigation. Extensive molecular dynamics simulations provided crucial insights into the conformational dynamics within the binding site, validating their stability and behavior. These findings contribute to our understanding of the potential therapeutic effectiveness of these compounds as PI3Kα inhibitors in pancreatic cancer. Communicated by Ramaswamy H. Sarma

The Role of Signaling Pathways in Pancreatic Cancer Targeted Therapy.

Signaling pathways play significant roles in the occurrence, development, and treatment of pancreatic cancer (PC). The main treatment options are surgery, chemotherapy, radiotherapy, arterial infusion chemotherapy in interventional therapy, and immunotherapy. Many studies have shown that signaling pathways perform a function in the occurrence and development of PC, for instance, phosphoinositide 3-kinase (PI3K)/AKT, nuclear factor-κB, Ras, interleukin (IL)-17B/IL-17RB, Wnt, and hepatocyte growth factor/c-MET, which play roles in the proliferation, metastasis, invasion, inhibition of apoptosis, promotion of angiogenesis, and drug resistance of PC. Interaction of signaling pathways has an impact on the biological behavior of PC; for example, activation of the neurotensin/NTSR1 pathway, which can activate mitogen-activated protein kinase, nuclear factor-κB, and other pathways related to PC stem cells, play an important role in PC, and an increase in their number is associated with the Wnt/β-catenin and PI3K pathways. Chemotherapy is the main method for the treatment of PC, but drug resistance limits its use. In addition, abnormal activation of IL-17B/IL-17RB signaling pathway is associated with drug resistance. This article discusses the signaling pathways that play different roles in the occurrence and development of PC, as well as current research on signaling pathways in PC treatment.

Long Non-Coding RNAs Associated with Mitogen-Activated Protein Kinase in Human Pancreatic Cancer

Long non-coding RNAs (lncRNAs) have emerged as a significant player in various cancers, including pancreatic cancer. However, how lncRNAs are aberrantly expressed in cancers is largely unknown. We hypothesized that lncRNAs would be regulated by signaling pathways and contribute to malignant phenotypes of cancer. In this study, to understand the significance of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), which is a major aberrant signaling pathway in pancreatic cancer, for the expression of lncRNAs, we performed comparative transcriptome analyses between pancreatic cancer cell lines with or without activation of MAPK. We identified 45 lncRNAs presumably associated with MAPK in pancreatic cancer cells; among these, LINC00941 was consistently upregulated by MAPK. The immediate genomic upstream region flanking LINC00941 was identified as a promoter region, the activity of which was found to be preferentially associated with MAPK activity via ETS-1 binding site. LINC00941 promoted cell proliferation in vitro. Moreover, TCGA data analysis indicated that high expression of LINC00941 was associated with poor prognosis of patients with pancreatic cancer. Transcriptomes comparing transcriptions between cells with and without LINC00941 knockdown revealed 3229 differentially expressed genes involved in 44 biological processes, including the glycoprotein biosynthetic process, beta-catenin-TCF complex assembly, and histone modification. These results indicate that MAPK mediates the aberrant expression of lncRNAs. LINC00941 is the lncRNA by MAPK most consistently promoted, and is implicated in the dismal prognosis of pancreatic cancer. MAPK-associated lncRNAs may play pivotal roles in malignant phenotypes of pancreatic cancer, and as such might represent both potentially valid therapeutic targets and diagnostic biomarkers.

IGFBP2 Drives Regulatory T Cell Differentiation through STAT3/IDO Signaling Pathway in Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies. Elevated regulatory T cell (Treg) infiltration has a potent immunosuppressive function in tumor biology, which contributes to low survival in PDAC. Nonetheless, the crosstalk between malignant cells and tumor-infiltrating Tregs in PDAC is not well understood. Here, clinical data demonstrates that the insulin-like growth factor binding protein 2 (IGFBP2) is associated with Treg accumulation in the microenvironment of PDAC in humans. Additionally, IGFBP2 increases Treg infiltration in the tumor microenvironment and promotes disease progression in mouse PDAC. Bioinformatic analysis and mechanistic assessment reveals IGFBP2 upregulated indoleamine 2, 3-dioxygenase (IDO) by activating signal transducer and activator of transcription 3 (STAT3) signaling in PDAC cells, thus inducing Treg differentiation and an immunosuppressive tumor microenvironment. These findings provide mechanistic insights into an important molecular pathway that promotes an immunosuppressive microenvironment, which suggests the IGFBP2 axis as a potential target for improved immune response in PDAC.

Targeting PI3K/AKT/mTOR Signaling Pathway in Pancreatic Cancer: From Molecular to Clinical Aspects

Although pancreatic cancer (PC) was considered in the past an orphan cancer type due to its low incidence, it may become in the future one of the leading causes of cancer death. Pancreatic ductal adenocarcinoma (PDAC) is the most frequent type of PC, being a highly aggressive malignancy and having a 5-year survival rate of less than 10%. Non-modifiable (family history, age, genetic susceptibility) and modifiable (smoking, alcohol, acute and chronic pancreatitis, diabetes mellitus, intestinal microbiota) risk factors are involved in PC pathogenesis. Chronic inflammation induced by various factors plays crucial roles in PC development from initiation to metastasis. In multiple malignant conditions such as PC, cytokines, chemokines, and growth factors activate the class I phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) (PI3K/AKT/mTOR) signaling pathway, which plays key roles in cell growth, survival, proliferation, metabolism, and motility. Currently, mTOR, AKT, and PI3K inhibitors are used in clinical studies. Moreover, PI3K/mTOR dual inhibitors are being tested in vitro and in vivo with promising results for PC patients. The main aim of this review is to present PC incidence, risk factors, tumor microenvironment development, and PI3K/AKT/mTOR dysregulation and inhibitors used in clinical, in vivo, and in vitro studies.

PKCι Is a Promising Prognosis Biomarker and Therapeutic Target for Pancreatic Cancer

Background: As the highest prevalent pancreatic cancer, pancreatic ductal adenocarcinoma (PDAC) ranks the 7th lethal malignancy worldwide. The late diagnosis, chemotherapeutic resistance, and high associated mortality make PDAC a dilemma facing the oncologists. Protein kinase C (PKC) enzymes have been shown to be important in different cancer progression. Methods: To understand the pattern of PKC enzymes in PDAC, we examined all PKC family member genes expression in PDAC and matched normal tissues. The critical role of PKCι was further investigated in different PDAC cells using cellular and molecular technology. Results: We found that PRKCI (PKCι) was the most significantly overexpressed PKCs in pancreatic cancer. However, little is known about its role and regulation of oncogenic signaling pathways in pancreatic cancer. In this study, we confirmed the overexpression of PKCι in PDAC, and this high expression was associated with poor prognosis of patients. We proved that knockdown of PKCι by small interfering RNA or shRNA significantly inhibited pancreatic cancer cell growth and migration or invasion. Conversely, PKCι overexpression promoted pancreatic cancer cell growth and migration. Moreover, bioinformatical and technical studies informed the participation of PKCι in regression of apoptosis in PDAC cells, which may be related to the regulation of both PI3K/AKT and Wnt/β-catenin pathways. Conclusions: Therefore, our results are adding more insight into the importance of PKCι in pancreatic cancer. PKCι induces pancreatic cancer progression through activation of PI3K/AKT and Wnt/β-catenin signaling pathways, which may provide a promising therapeutic target for pancreatic cancer.

SIRT6 promotes ferroptosis and attenuates glycolysis in pancreatic cancer through regulation of the NF-κB pathway.

Pancreatic cancer (PC) is a malignant tumor with high mortality worldwide. SIRT6 plays versatile roles in human cancers. However, SIRT6 has rarely been studied in PC. The purpose of the present study was to explore the function and potential mechanism of SIRT6 in PC. The expression of SIRT6 in PC tissues and cells was detected by reverse transcription-quantitative PCR and western blotting. The overall survival time was analyzed through the Kaplan Meier method. Cell viability was measured by the Cell Counting Kit-8 assay. The Fe2+ content, glucose uptake, lactic acid and ATP production were detected through the corresponding kits. ROS was evaluated using the DCFH-DA detection kit. Protein expression was assessed by immunohistochemistry or western blot analysis. In the present study, SIRT6 was lowly expressed in PC tissues and cells compared with normal tissues and cells. Moreover, the low expression of SIRT6 was associated with a poor prognosis in patients with PC. Upregulation of SIRT6 significantly promoted the ferroptosis and inhibited the glycolysis in PC cells. However, knockdown of SIRT6 resisted ferroptosis and increased glycolysis in PC cells. Further studies found that the activation of NF-κB could reverse the effect of SIRT6 on PC cells. In addition, overexpression of SIRT6 restrained the growth of xenografted tumors and suppressed the nuclear transcription of NF-κB in vivo. Collectively, the present study indicated that SIRT6 promoted ferroptosis and inhibited glycolysis through inactivating the NF-κB signaling pathway in PC. These findings suggested that SIRT6 may become a therapeutic target for PC.

The Role of Feedback Loops in Targeted Therapy for Pancreatic Cancer.

Pancreatic cancer is the leading cause of cancer-related deaths worldwide, with limited treatment options and low long-term survival rates. The complex and variable signal regulation networks are one of the important reasons why it is difficult for pancreatic cancer to develop precise targeted therapy drugs. Numerous studies have associated feedback loop regulation with the development and therapeutic response of cancers including pancreatic cancer. Therefore, we review researches on the role of feedback loops in the progression of pancreatic cancer, and summarize the connection between feedback loops and several signaling pathways in pancreatic cancer, as well as recent advances in the intervention of feedback loops in pancreatic cancer treatment, highlighting the potential of capitalizing on feedback loops modulation in targeted therapy for pancreatic cancer.

Overexpressed integrin alpha 2 inhibits the activation of the transforming growth factor \u03b2 pathway in pancreatic cancer via the TFCP2-SMAD2 axis

BackgroundIntegrin alpha 2 (ITGA2) has been recently reported to be an oncogene and to play crucial roles in tumor cell proliferation, invasion, metastasis, and angiogenesis. Our previous study showed that ITGA2 was overexpressed in pancreatic cancer and promoted its progression. However, the mechanism of ITGA2 overexpression and other mechanisms for promoting the progression of pancreatic cancer are still unclear.MethodsThe GEPIA database was used to confirm the expression of ITGA2 in pancreatic cancer. To verify the influence of ITGA2 and TGF-β on the morphological changes of pancreatic cancer and tumor cell progression, we conduct CCK8 test, plate cloning, flow cytometry experiments and animal experiments. Then we conduct Western blot, RT-qPCR to explore the relationship between ITGA2 and TGF-β, and then find the key molecules which can regulate them by immunoprecipitation, Western blot, RT-qPCR, CHIP, nuclear and cytoplasmic separation test.ResultsThe results of the present study show that the abnormal activation of KRAS induced the overexpression of ITGA2 in pancreatic cancer. Moreover, ITGA2 expression significantly suppressed the activation of the TGF-β pathway. ITGA2 silencing enhanced the anti-pancreatic cancer proliferation and tumor growth effects of TGF-β. Mechanistically, ITGA2 expression suppressed the activation of the TGF-β pathway by inhibiting the SMAD2 expression transcriptionally. In addition, it interacted with and inhibited the nuclear translocation of TFCP2, which induced the SMAD2 expression as a transcription factor. Furthermore, TFCP2 also induced ITGA2 expression as a transcription factor, and the TFCP2 feedback regulated the ITGA2-TFCP2-SMAD2 pathway.ConclusionsTaken together, these results indicated that ITGA2 expression could inhibit the activation of the TGF-β signaling pathway in pancreatic cancer via the TFCP2-SMAD2 axis. Therefore, ITGA2, by effectively enhancing the anti-cancer effects of TGF- β, might be a potential clinical therapeutic target for pancreatic cancer.

HIST3H2A is a potential biomarker for pancreatic cancer: A study based on TCGA data.

The family of histone H2A proved that there are a lot of variants associated with cancer development. The link between HIST3H2A and pancreatic cancer has never been noted before. Our research suggests that HIST3H2A affects pancreatic tumor immune process and prognosis of patients, through the JAK STAT pathway, so it is expected to become the biomarker of pancreatic cancer.Gene expression profiles and clinical data of pancreatic cancer patients were downloaded from The Cancer Genome Atlas database (TCGA) and The Genotype Tissue Expression (GETx) project. R software (Rx64 3.6.0) was utilized to analyze. Gene set enrichment analysis (GSEA) was used to analyze HIST3H2A related signaling pathways in pancreatic cancer. CIBERSORT is applied to estimate the compositional patterns of the 22 types of immune cell fraction based on bulk expression data.HIST3H2A was expressed at higher in pancreatic cancer tissues than normal pancreatic tissues. Kaplan–Meier survival analysis suggested that the level of HIST3H2A expression affect prognosis of pancreatic cancer patients. Univariate Cox analysis and Multivariate Cox analysis suggested that HIST3H2A expression is a prognostic factor of pancreatic cancer. Cor expression analysis indicated that the genes positively correlated with HIST3H2A expression trend were DCST1-AS1, HIST1H2BD, SLC12A9-AS1. GSEA showed that the JAK-STAT signaling pathway was enriched in the HIST3H2A high expression phenotype, whereas intestinal network for IgA production, Asthma and Chemokine signaling pathway were enriched in the HIST3H2A low expression phenotype. In additional, results showed that CD8 T cells (P = .007), activated CD4 memory T cells (P = .001), and monocytes (P = .002) were more abundant in lower HIST3H2A expression groups.HIST3H2A is a promising biomarker for predicting prognosis of pancreatic cancer, and it could be a potential therapeutic target. HIST3H2A might regulate the progression of tumor immune in pancreatic cancer through modulating the JAK-STAT pathway. In addition, the role HIST3H2A in pancreatic cancer may be related to DCST1-AS1, HIST1H2B, SLC12A9-AS1. However, more research is necessary to validate findings.

Truncated O-GalNAc glycans impact on fundamental signaling pathways in pancreatic cancer.

Truncated O-GalNAc glycosylation is an important feature of pancreatic ductal adenocarcinomas (PDAC) and expression of truncated O-GalNAc glycans is strongly associated with decreased survival and poor prognosis. It has been proven, that aberrant O-GalNAc glycosylation influence PDAC signaling to promote oncogenic properties, but elucidation of the influence of truncated O-GalNAc glycosylation on different signaling molecules has just been started. We herein elucidated the impact of aberrant O-GalNAc glycosylation on two important PDAC signaling pathways, namely AKT/mTOR and RAS/MAPK. In PDAC cells expressing truncated O-GalNAc glycans, we identified differentially expressed proteins associated with AKT/mTOR and RAS/MAPK pathways using quantitative proteomics. Since AKT, a key-signaling molecule in PDAC, was among the identified proteins, we analyzed AKT and found a strikingly enhanced S473 phosphorylation and identified a previously unknown O-GalNAc-modification. Consecutive analysis of COSMC knockdowns in PDAC revealed strong effects on AKT upstream and downstream effector molecules. Interestingly, truncated O-GalNAc glycans could facilitate an mTORC1 inhibitor resistance using AZD8055. In addition, as AKT/mTOR pathway has extensive cross talks with RAS/MAPK pathway we analyzed the pathways and found it negatively regulated. Finally, we found that the expression of epithelial-mesenchymal-transition markers, key features of aggressive PDACs cells, are enhanced and truncated O-GalNAc glycans enhance pancreatic cancer cell growth in a xenograft mouse model. Our study demonstrates that truncated O-GalNAc glycans have a strong impact on AKT/mTOR and RAS/MAPK signaling pathways, are modulated by EGF or IGF-1 signaling and should be considered for targeted therapy of these pathways in PDAC.

Oncogene APOL1 promotes proliferation and inhibits apoptosis via activating NOTCH1 signaling pathway in pancreatic cancer

APOL1 encodes a secreted high-density lipoprotein, which has been considered as an aberrantly expressed gene in multiple cancers. Nevertheless, the role of APOL1 in the regulatory mechanisms of pancreatic cancer remains unknown and should be explored. We identified APOL1 was abnormally elevated in human pancreatic cancer tissues compared with that in adjacent tissues and was associated with poor prognosis. The effects of APOL1 in PC cell proliferation, cell cycle, and apoptosis was verified via functional in vitro and in vivo experiments. The results showed that knockdown of APOL1 significantly inhibited the proliferation and promoted apoptosis of pancreatic cancer. In addition, we identified APOL1 could be a regulator of NOTCH1 signaling pathway using bioinformatics tools, qRT-PCR, dual-luciferase reporter assay, and western blotting. In summary, APOL1 could function as an oncogene to promote proliferation and inhibit apoptosis through activating NOTCH1 signaling pathway expression in pancreatic cancer; therefore, it may act as a novel therapeutic target for pancreatic cancer.

Dual Roles of the Activin Signaling Pathway in Pancreatic Cancer.

Activin, a member of the TGF-β superfamily, is involved in many physiological processes, such as embryonic development and follicle development, as well as in multiple human diseases including cancer. Genetic mutations in the activin signaling pathway have been reported in many cancer types, indicating that activin signaling plays a critical role in tumorigenesis. Recent evidence reveals that activin signaling may function as a tumor-suppressor in tumor initiation, and a promoter in the later progression and metastasis of tumors. This article reviews many aspects of activin, including the signaling cascade of activin, activin-related proteins, and its role in tumorigenesis, particularly in pancreatic cancer development. The mechanisms regulating its dual roles in tumorigenesis remain to be elucidated. Further understanding of the activin signaling pathway may identify potential therapeutic targets for human cancers and other diseases.

Abstract 1289: Conjugation of indomethacin with novel oleanolic acid oximes increases its Nrf2 and NF-κB signaling pathways modulating effect in pancreatic cancer cells

Abstract Chronic inflammation is a key factor in the etiology of neoplastic diseases, including pancreatic cancer. Nonsteroidal anti-inflammatory drugs (NSAIDs) were approved for the chemoprevention of colon tumors and suggested for pancreas cancers prophylaxis. Anti-inflammatory and anti-tumorigenic activities are also exerted by naturally occurring and synthetic triterpenoids. Coupling of triterpenoid analogues with NSAIDs may enhance this effect and prevent the unfavorable side effects related to NSAIDs long-term use. In this study novel oleanolic acid oxime (OAO) derivatives conjugated with indomethacin (IND) differing in substitution group at position C-17 were evaluated in the context of their possible modulating effect of Nrf2-ARE and NF-κB signaling pathways in pancreatic cancer cells.PSN-1 cells were incubated for 24h with IND and OAO-IND derivatives at the concentrations of 10µM and 20µM selected based on the results of the MTT assay. The activation of Nrf2 and NF-κB was assessed by the evaluation of its translocation into the nucleus and binding to specific DNA sequences by the ELISA assay. Expression of Nrf2, SOD-1, NF-κBp50, NF-κBp65 and COX-2 was evaluated by RT-PCR and Western blot methods.Cell viability was affected mostly by 3-indomethacinoxyiminoolean-12-en-28-oic acid morpholide and 3-indomethacinoxyiminoolean-en-28-oic acid benzyl ester. The level of Nrf2 in the nucleus and binding to ARE sequence was decreased in PSN-1 cells, similarly as was NF-κBp50 and NF-κBp65 binding and nuclear accumulation. As result of diminished activation of these transcription factors decreased expression of SOD-1 and COX-2 i.e. mRNA and protein levels were found. These results indicate that the OAO-IND derivatives, particularly morpholide and benzyl ester conjugates, are more potent suppressors of NF-κB signaling pathway than IND alone. Moreover, conjugation of IND with novel OAO may protect cancer cells against chemoresistance through inhibition of the Nrf2-ARE pathway. Those novel compounds might be considered the potential modulators of hepatocellular carcinoma therapy and chemopreventive agents. Funding: This work was supported by Polish National Science Centre, grant 2016/21/B/NZ7/01758. Citation Format: Wanda Baer-Dubowska, Maria Narozna, Violetta Krajka-Kuźniak, Barbara Bednarczyk-Cwynar. Conjugation of indomethacin with novel oleanolic acid oximes increases its Nrf2 and NF-κB signaling pathways modulating effect in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1289.