Aim: We investigated the expression of the inhibitory costimulatory molecules B7-H1, B7-H3, and B7-H4 in human pancreatic cancer to define their clinical significance and mechanism in a tumor microenvironment. Patients and methods: Sixty-three pancreatic cancer tissues and 12 normal pancreatic tissues were examined in our research. Patients were enrolled in the study between December 2000 and August 2010. Expression levels of the B7 family of molecules and densities of tumor-infiltrating lymphocytes in the tissues were characterized with immunohistochemical assays. Results: More than 50% of the patients expressed B7-H1 and B7-H4, and nearly 100% of the patients expressed B7-H3. B7-H1 expression was correlated with tumor size, B7-H3 expression was correlated with lymph-node metastasis and differentiation grade, and B7-H4 expression was correlated with tumor size, lymph-node metastasis, and invasion depth. High B7-H4 expression was also correlated with poor survival in pancreatic cancer. We determined the value of these three B7 family molecules in the postoperative survival prognosis for patients with pancreatic cancer, and pancreatic cancer patients with less coexpression of the B7 family of molecules had a significantly higher survival rate. B7-H1 expression was found to be negatively related to the intensity of both CD3⁺ T cells and CD8⁺ T cells, and B7-H4 expression was negatively related to CD3⁺ T-cell infiltration intensity, but not to CD8⁺ T cells. Conclusion: B7-H1, B7-H3, and B7-H4 are involved in pancreatic cancer progression, and their coexpression could be a valuable prognostic indicator. Negative regulation of T-cell infiltration might be the main mechanism of action of the B7 family of molecules in pancreatic cancer.

The lncRNA colorectal neoplasia differentially expressed (lncRNA CRNDE) has been reported to play a pivotal role in various cancers. However, the expression and function of CRNDE in pancreatic cancer remain unclear. The objective of this study was to investigate the effects of CRNDE on pancreatic cancer and the underlying mechanisms. The expression of CRNDE in pancreatic cancer tissues and cell lines was determined by RT-qPCR. Proliferation and angiogenesis were detected by MTT, colony formation, transwell and tube formation assays in vitro and in vivo. ELISA assay was used to detect the secretion of VEGFA. IHC was performed to test the expression levels of Ki67 and CD31. The binding sites between CRNDE, CDKN2D and miR-451a were predicted by bioinformatics analysis. Dual luciferase reporter and RNA immunoprecipitation assays were conducted to confirm the interaction with each other. The results showed that CRNDE was significantly up-regulated in pancreatic cancer tissues as well as cell lines. CRNDE overexpression promoted the progression and angiogenesis of pancreatic cancer cells in vitro and in vivo. Moreover, we identified that CRNDE functioned as a sponge for miR-451a and CRNDE overexpression inhibited the expression of miR-451a. Furthermore, we confirmed that miR-451a directly interacted with CDKN2D and negatively regulated CDKN2D expression. In addition, CRNDE was found to positively regulate CDKN2D expression and mediate pancreatic cancer cell proliferation and angiogenesis through miR-451a/CDKN2D axis. CRNDE modulates cell proliferation and angiogenesis via miR-451a/CDKN2D axis in pancreatic cancer, which provides a potential therapeutic target for pancreatic cancer treatment.

Patients bearing liver metastasis of pancreatic adeno carcinoma (PDAC) suffer from poor prognosis due to its short duration and high mortality. Complex tumor microenvironment (TME) exists in liver metastatic niches, and tumor-associated macrophages (TAMs) have play vital roles in metastasis generation and outgrowth. We have discovered that M2 type TAM-derived SEMA5A could bind to its tumor cell-expressed receptor PLXNB3 to promote tumor cell proliferation and outgrowth. We utilized liver metastasis samples of PDAC patients, intrasplenic injection mouse models, and Kras^G12D/Trp53^R172H/Pdx1-Cre (KPC) mouse models for in vivo study. In mechanism investigation, we have discovered that SEMA5A-PLXNB3 axis could achieve tumor cell proliferation and survival via enhancing aerobic glycolysis termed as the Warburg effects. Targeting this axis may be a potential therapeutic approach for PDAC patients with unresectable liver metastasis.

MUC16, encoding cancer antigen 125, is a frequently mutated gene in gastric cancer. In addition, MUC16 mutations seem to result in a better prognosis in gastric cancer. However, the mechanisms that lead to a better prognosis by MUC16 mutations have not yet been clarified. To delve deeper into the underlying mechanisms that explain why MUC16 mutations signal a better prognosis in gastric cancer. We used multi-omics data, including mRNA, simple nucleotide variation, copy number variation and methylation data from The Cancer Genome Atlas, to explore the relationship between MUC16 mutations and prognosis. Cox regression and random survival forest algorithms were applied to search for hub genes. Gene set enrichment analysis was used to elucidate the molecular mechanisms. Single-sample gene set enrichment analysis and “EpiDISH” were used to assess immune cells infiltration, and “ESTIMATE” for analysis of the tumor microenvironment. Our study found that compared to the wild-type group, the mutation group had a better prognosis. Additional analysis indicated that the MUC16 mutations appear to activate the DNA repair and p53 pathways to act as an anti-tumor agent. We also identified a key gene, NPY1R (neuropeptide Y receptor Y1), which was significantly more highly expressed in the MUC16 mutations group than in the MUC16 wild-type group. The high expression of NPY1R predicted a poorer prognosis, which was also confirmed in a separate Gene Expression Omnibus cohort. Further susceptibility analysis revealed that NPY1R might be a potential drug target for gastric cancer. Furthermore, in the analysis of the tumor microenvironment, we found that immune cells in the mutation group exhibited higher anti-tumor effects. In addition, the tumor mutation burden and cancer stem cells index were also higher in the mutation group than in the wild-type group. We speculated that the MUC16 mutations might activate the p53 pathway and DNA repair pathway: alternatively, the tumor microenvironment may be involved.

Background: Pancreatic cancer (PC) is a highly malignant tumor associated with low survival rates. It is challenging to predict the survival of surgically resected patients with PC. A prognostic staging tool could be beneficial to guide treatments and also aid post-treatment surveillance. This study aimed to identify tissue-based DNA methylation risk-score model to predict the prognosis of surgically resected pancreatic cancer patients. Methods: We performed a monocentric, retrospective study that included 50 patients with stage I–II PC from The First Affiliated Hospital of Soochow University (SU cohort). Both tumor and adjacent normal tissues were obtained from each patient and subjected to capture-based targeted methylation profiling. Results: In total, 1,162 DNA methylation blocks (DMBs) were differentially methylated in tumor tissues compared with adjacent long-distance tissues (P<0.05). Least Absolute Shrinkage and Selection Operator (LASSO) and stepwise regression analyses revealed a significant correlation between the methylation signature (risk score) and overall survival (OS). Patients in the high-risk group showed significantly poorer OS than those in the low-risk group in the survival analysis [P≤0.001; area under curve (AUC) at 1 year, 0.789; AUC at 2 years, 0.852]. The risk score was also validated using clinical and methylation data of 166 PC patients from The Cancer Genome Atlas pancreatic ductal adenocarcinoma (TCGA-PDAC) dataset. Patients in the high-risk group showed significantly poorer OS than those in the low-risk group (P=0.004; AUC at 1 years, 0.677; AUC at 3 years, 0.611). When clinical parameters were considered, the risk score was the only independent prognostic parameter (P<0.001) in the Cox regression analysis. Furthermore, low-risk patients had higher levels of immune infiltration, anti-tumor immune activation, and increased sensitivity to gemcitabine and paclitaxel. In contrast, high-risk patients had lower KRAS mutation rates and benefited more from cisplatin. Conclusions: In our study, we constructed and validated a tissue-based DNA methylation risk-score model to predict prognosis and identify PC patients with a high mortality risk at the time of surgery. This model might provide a tissue-based prognostic assessment tool for clinicians to aid their treatment decision-making.