Galectin‐1 is implicated in making tumor cells immune privileged, in part by regulating the survival of infiltrating T cells. Galectin‐1 is strongly expressed in activated pancreatic stellate cells (PSCs); however, whether this is linked to tumor cell immune escape in pancreatic cancer is unknown. Galectin‐1 was knocked down in PSCs isolated from pancreatic tissues using small interfering RNA (siRNA), or overexpressed using recombinant lentiviruses, and the PSCs were cocultured with T cells. CD3⁺, CD4⁺ and CD8⁺ T cell apoptosis was detected by flow cytometry; T cell IL‐2, IL‐4, IL‐5 and INF‐γ production levels were quantified using ELISA. Immunohistochemical analysis showed increased numbers of PSCs expressed Galectin‐1 (p < 0.01) and pancreatic cancers had increased CD3⁺ T cell densities (p < 0.01) compared to normal pancreas or chronic pancreatitis samples. In coculture experiments, PSCs that overexpressed Galectin‐1 induced apoptosis of CD4⁺ T cells (p < 0.01) and CD8⁺ T cells (p < 0.05) significantly, compared to normal PSCs. Knockdown of Galectin‐1 in PSCs increased CD4⁺ T cell (p < 0.01) and CD8⁺ T cell viability (p < 0.05). Supernatants from T cells cocultured with PSCs that overexpressed Galectin‐1 contained significantly increased levels of Th2 cytokines (IL‐4 and IL‐5, p < 0.01) and decreased Th1 cytokines (IL‐2 and INF‐γ, p < 0.01). However, the knockdown of PSC Galectin‐1 had the opposite effect on Th1 and Th2 cytokine secretion. Our study suggests that the overexpression of Galectin‐1 in PSCs induced T cell apoptosis and Th2 cytokine secretion, which may regulate PSC‐dependent immunoprivilege in the pancreatic cancer microenvironment. Galectin‐1 may provide a novel candidate target for pancreatic cancer immunotherapy.

The aberrant expression of microRNAs (miRNAs) has emerged as important hallmarks of cancer. However, the molecular mechanisms underlying the differences of miRNA expression remain unclear. Many studies have reported that miR-98-5p plays vital functions in the development and progression of multiple cancers. However, its role in pancreatic ductal adenocarcinoma (PDAC) remains unknown. The expression of miR-98-5p and its specific target gene were determined in human PDAC specimens and cell lines by miRNA qRT-PCR, qRT-PCR and western blot. The effects of miR-98-5p depletion or ectopic expression on PDAC proliferation, migration and invasion were evaluated in vitro using CCK-8 proliferation assays, colony formation assays, wound healing assays and transwell assays. Furthermore, the in vivo effects were investigated using the mouse subcutaneous xenotransplantation and pancreatic tail xenotransplantation models. Luciferase reporter assays were employed to identify interactions between miR-98-5p and its specific target gene. MiR-98-5p expression was significantly lower in cancerous tissues and associated with tumor size, TNM stage, lymph node metastasis and survival. Notably, a series of gain- and loss-of-function assays elucidated that miR-98-5p suppressed PDAC cell proliferation, migration and invasion both in vitro and in vivo. Luciferase reporter assays, western blot and qRT-PCR revealed MAP4K4 to be a direct target of miR-98-5p. The effects of ectopic miR-98-5p were rescued by MAP4K4 overexpression. In contrast, the effects of miR-98-5p depletion were impaired by MAP4K4 knockdown. Furthermore, miR-98-5p suppressed the MAPK/ERK signaling pathway through downregulation of MAP4K4. In addition, the expression level of miR-98-5p was negatively correlated with MAP4K4 expression in PDAC tissues and cell lines. These results suggest that downregulation of miR-98-5p promotes tumor development by downregulation of MAP4K4 and inhibition of the downstream MAPK/ERK signaling, thus, highlighting the potential of miR-98-5p as a therapeutic target for PDAC.

Patients with potentially resectable pancreatic ductal adenocarcinoma (PDAC) are frequently found to be unresectable on exploration due to small distant metastasis. This study was to investigate predictors of small distant metastasis in patients with potentially resectable PDAC. Patients who underwent surgical exploration for potentially resectable PDAC from 2013 to 2014 were reviewed retrospectively and divided into two groups according to whether distant metastases were encountered on exploration. Then, univariate and multivariate logistic regression analyses were used to identify predictors of distant metastasis. A scoring system to predict distant metastasis of PDAC on exploration was constructed based on the regression coefficient of a multivariate logistic regression model. A total of 235 patients were included in this study. Mean age of the study population was 61.7 ± 10.4 years old. Upon exploration, distant metastases were found intraoperatively in 62 (26.4%) patients, while the remaining 173 were free of distant metastases. Multivariate logistic regression analysis identified that age ≤ 62 years old (p < 0.001), male sex (p = 0.011), tumor size ≥4.0 cm (p < 0.001), alanine aminotransferase level (ALT) < 125 U/L (p < 0.001), and carbohydrate antigen (CA19–9) level ≥ 385 U/mL (p < 0.001) were independent risk factors for occult distant metastasis of PDAC. A preoperative scoring system (0–8 points) for distant metastasis on exploration was constructed using these five factors. The receiver operating characteristic curves showed that the area under the curve of this score was 0.85. A score of 6 points was suggested to be the optimal cut-off value, and the sensitivity and specificity were 85% and 69%, respectively. Distant metastasis is still frequently encountered on exploration for patients with potentially resectable PDAC. Younger age, male sex, larger tumor size, low ALT level and high CA19–9 level are independent predictors of unexpected distant metastasis on exploration.

Overexpression of paternally expressed gene-10 (PEG10) is known to promote the progression of several carcinomas, however, its role in pancreatic cancer (PC) is unknown. We investigated the expression and function of PEG10 in PC. PEG10 expression and correlation with PC progression was assessed in cancerous tissues and paired non-cancerous tissues. Further, the role of PEG10 in PC cell progression and the underlying mechanisms were studied by using small interfering RNA (Si-RNA). PEG10 expression was significantly higher in cancerous tissues and correlated with PC invasion of vessels and Ki-67 expression. Si-RNA mediated PEG10 knockdown resulted in inhibition of proliferation and G0/G1 cell cycle arrest, which was mediated by p21 and p27 upregulation. A decrease in PC cell invasion and migration, mediated by ERK/MMP7 pathway, was observed in PEG10 knockdown group. Further, findings of ChIP assay suggested that E2F-1 could directly enhance the expression of PEG10 through binding to PEG10 promoter. In conclusion, PEG10 was identified as a prognostic biomarker for PC and E2F-1 induced PEG10 could promote PC cell proliferation, invasion, and metastasis.

Background: Delayed gastric emptying (DGE) is a common complication after pancreaticoduodenectomy (PD) or pylorus preserving pancreaticoduodenectomy (PPPD). However, its risk factors are still unclear. This meta-analysis aimed to identify the potential risk factors of DGE among patients undergoing PD or PPPD. Methods: We searched PubMed, EMBASE, Web of Science, Cochrane Library, Google Scholar and ClinicalTrial.gov for studies that examined the clinical risk factors of DGE after PD or PPPD from inception through July 31, 2022. We pooled odds ratios (ORs) with 95% confidence intervals (CIs) using random-effects or fixed-effects models. We also performed heterogeneity, sensitivity, and publication bias analyses. Results: The study included a total of 31 research studies, which involved 9205 patients. The pooled analysis indicated that out of 16 non-surgical related risk factors, three risk factors were found to be associated with an increased incidence of DGE. These risk factors were older age (OR 1.37, P=0.005), pre-operative biliary drainage (OR 1.34, P=0.006), and soft pancreas texture (OR 1.23, P=0.04). On the other hand, patients with dilated pancreatic duct (OR 0.59, P=0.005) had a decreased risk of DGE. Among 12 operation related risk factors，more blood loss (OR 1.33, P=0.01), post-operative pancreatic fistula (POPF) (OR 2.09, P<0.001), intra-abdominal collection (OR 3.58 , P=0.001), and intra-abdominal abscess (OR 3.06, P<0.0001) were more likely to cause DGE. However, our data also revealed 20 factors did not support stimulative factors influencing DGE. Conclusion: Age, pre-operative biliary drainage, pancreas texture, pancreatic duct size, blood loss, POPF, intra-abdominal collection and intra-abdominal abscess are significantly associated with DGE. This meta-analysis may have utility in guiding clinical practice for improvements for screening patients with high risk of DGE and selecting appropriate treatment measure.

Minichromosome maintenance (MCM) proteins play important roles in DNA replication by interacting with other factors which participate in the regulation of DNA synthesis. Abnormal over-expression of MCMs was observed in numerous malignancies, such as colorectal cancer. However, the expression of MCMs in pancreatic cancer (PC) was less investigated so far. This study was designed to analyze the expression and prognostic roles of MCM1-10 in PC based on the data provided by The Cancer Genome Atlas (TCGA). Pearson χ² test was applied to evaluate the association of MCMs expression with clinicopathologic indicators, and biomarkers for tumor biological behaviors. Kaplan-Meier plots and log-rank tests were used to assess survival analysis, and univariate and multivariate Cox proportional hazard regression models were used to recognize independent prognostic factors. MCM1-10 were generally expressed in PC samples. The levels of some molecules were markedly correlated with that of biomarkers for S phase, proliferation, gemcitabine resistance. And part of these molecules over-expression was significantly associated with indicators of disease progression, such as depth of tumor invasion and lymph node metastasis. Furthermore, MCM2, 4, 6, 8, and 10 over-expression was remarkably associated with shorter disease free survival time, and MCM2, 4,8, and 10 over-expression was associated with shorter overall survival time. Further multivariate analysis suggested that MCM8 was an independent prognostic factor for PC. MCMs abnormal over-expression was significantly associated with PC progression and prognosis. These molecules could be regarded as prognostic and therapeutic biomarkers for PC. The roles of MCMs may be vitally important and the underlying mechanisms need to be furtherinvestigated.