Gastric cancer (GC) is one of the most common malignancies with high mortality rate. MiR-152 may exert the function of tumor suppressor by regulating its target gene, including PIK3CA. Nevertheless, all of the described functions are referred explicitly to miR-152-3p, while miR-152-5p as a passenger strand is poorly realized and entirely ignored. We previously selected miR-152-5p as a candidate using cell migration inhibition screening for GC cells and predicted that miR-152-5p might also target PIK3CA. In this study, we found an abnormal proportion of miR-152-3p / miR-152-5p in GC (gastric cancer) tissues and cells and demonstrated that miR-152-5p had poorer stability in GC cells, revealing the possibility that miR-152-5p is abnormally "suppressed" in gastric cancer. We also investigated and confirmed the role of miR-152-5p in GC by a series of experiments, and found that miR-152-5p modulated cell viability, migration, invasion, and cell-cycle progression of human GC cells, and also inhibited tumor growth and metastasis in vivo partially by targeting PIK3CA. More interestingly, it was proved that miR-152-3p and miR-152-5p had synergistic effects on the inhibition of PIK3CA in GC cells. The results of this study suggest that miR-152-5p may act as a tumor suppressor in SGC-7901 gastric cancer cells via targeting PIK3CA. Further, the study provides a novel insight into the roles of miRNA* during carcinogenesis.

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Background: Studies have shown that miR-502-5p functions as a tumor suppressor and is associated with tumor growth and metastasis. This study intends to uncover the potential mechanism of miR-502-5p functioning as a tumor suppressor in gastric cancer. Methods: Expression levels of miR-502-5p and PD-L1 were measured by using qRT-PCR. Cell proliferation abilities were examined by EDU incorporation assay. Cell migration, invasion and cell cycle analysis of cells were determined by transwell assay, transwell-matrigel assay and flow cytometry, respectively. The relationship between miR-502-5p expression and the overall survival of xenograft tumor mice was statistically analyzed. Bioinformatics analysis and luciferase reporter assays were applied to analyze the relationship between miR-502-5p and CD40, STAT3 or PD-L1. Expressions of CD40, STAT3 and PD-L1 at protein level were detected by western blot. Results: The results showed that miR-502-5p was significantly downregulated in gastric cancer tumor tissues compared with adjacent normal tissues. Overexpression of miR-502-5p significantly attenuated the proliferation, migration/invasion and induced the G1 phase arrest of gastric cancer cells. Consistently, miR-502-5p suppressed tumor growth and metastasis in vivo. Mechanically, we demonstrated that miR-502-5p had inhibited the malignant behaviour of gastric cancer by down-regulating PD-L1 expression at transcriptional level and post-transcriptional levels. Conclusions: These findings suggest that miR-502-5p acts as a tumor suppressor in gastric cancer (GC). MiR-502-5p/ PD-L1 may be a novel therapeutic target in GC treatment.

Objective This study aimed to evaluate the efficacy and safety of using Hemocoagulase Bothrops Atrox in the submucosal injection solution for endoscopic submucosal dissection (ESD). Methods A total of 120 patients with superficial neoplastic lesions of the esophagus, stomach, and colon receiving ESD were randomly divided into two groups: The epinephrine group used epinephrine-containing submucosal fluid cushion for ESD, while the hemocoagulase group used Hemocoagulase Bothrops Atrox-containing submucosal fluid cushion for ESD. The preoperative, intraoperative, and postoperative clinical parameters and postoperative adverse events of the two groups were recorded, and comparative analysis within and between groups was performed. Results There was no significant difference in the demographic and clinical characteristics between the hemocoagulase and epinephrine group (all P > 0.05). ESD surgery was completed in all patients. The hemocoagulase group had significantly shorter surgery time (P = 0.003) and less number of intraoperative bleeding (P = 0.010) than the epinephrine group. However, there was no significant difference in the incidences of postoperative delayed hemorrhage, and adverse events between the two groups (all P > 0.05). Multivariate linear regression demonstrated that the epinephrine group had significantly more number of intraoperative bleeding (B: 0.98, 95% confidence interval: 0.04–1.93) as compared with the hemocoagulase group. Conclusion Compared with epinephrine, using Hemocoagulase Bothrops Atrox in the submucosal injection for ESD surgery can significantly reduce the number of intraoperative bleeding, shorten the operation time, and did not elevate the incidence of adverse events.