The predictive value of miR-132-3p combined with Prognostic Nutritional Index (PNI) for gastric cancer prognosis.

Background: previous studies have demonstrated that the Prognostic Nutritional Index (PNI) can predict the prognosis of gastric cancer (GC) patients. However, few studies have focused on the auxiliary role of miRNA in predicting the prognosis of GC.

Objective: this study aimed to clarify the role of the combined use of miR-132-3p and PNI to predict the prognosis of GC patients.

Methods: a total of 126 patients with GC who underwent surgical treatment at our institution were included in the study. The qRT-PCR data was used to assess the expression of miR-132-3p in tumor and adjacent normal tissues. The predictive value of miR-132-3p and PNI for postoperative prognosis, and the relationships between miR-132-3p, PNI, and preoperative clinical characteristics, were assessed using ROC, χ², Kaplan-Meier survival analysis, and Cox regression analysis. Bioinformatics analyses and dual-luciferase reporter assay were conducted to elucidate the biological function of miR-132-3p and the underlying molecular mechanisms.

Results: miR-132-3p was downregulated in GC tumor tissues and significantly and positively correlated with PNI. Both miR-132-3p and PNI were significantly associated with TNM stage and lymph node metastasis. Postoperative GC patients with low miR-132-3p expression and low PNI had lower survival rates, and both were independent risk factors for poor prognosis. The combination of miR-132-3p and PNI demonstrated better sensitivity and specificity to predict postoperative prognosis than either indicator alone. miR-132-3p may be involved in DNA damage response, angiogenesis, and immune response associated with GC development. MAPK1 was identified as a target gene regulated by miR-132-3p in GC.

Conclusion: the combination of miR-132-3p and PNI can effectively improve the predictive value of postoperative prognosis in GC patients. The combination of miR-132-3p and PNI, which are strongly correlated with pathological characteristics and can be readily obtained, has a potential clinical applicability in the prognosis of patients with GC.