piR-38,736 promotes gastric cancer cell proliferation by downregulating SMAD4 expression.

PIWI-interacting RNAs (piRNAs) play an important role in cancer development and progression. Although recent studies had advanced our understanding of the functions of various piRNAs in cancer, the specific role of piR-38736 in gastric cancer remained poorly understood. This study aimed to investigate the clinical significance and underlying mechanisms of piR-38736 in gastric cancer. This study found that piR-38736 was significantly upregulated in gastric cancer cells and tissues. Positive piR-38736 expression was closely correlated with larger tumor size and medium to poor differentiation. Survival analysis revealed that patients with positive piR-38736 expression had significantly shorter survival times compared to those with negative expression. Knockdown of piR-38736 markedly inhibited cell proliferation and tumor growth in gastric cancer. Furthermore, piR-38736 was found to directly bind to the 3' untranslated region (UTR) of SMAD4 mRNA, resulting in significant downregulation of SMAD4 at both the mRNA and protein levels upon overexpression of piR-38,736. In conclusion, these findings indicate that piR-38,736 promotes cell proliferation and tumor growth in gastric cancer by downregulating SMAD4 expression. piR-38,736 may serve as a prognostic biomarker and a potential therapeutic target for gastric cancer. Further studies are required to fully elucidate the underlying mechanisms of piR-38,736 and explore its clinical implications in gastric cancer management.