Mir-638 Upregulation in Serum and Tissues Functions As a Diagnostic and Prognostic Biomarker and Facilitates Prostate Cancer Progression

OBJECTIVE:To explore the expression profile of miR-638 in serum and tumor tissues of prostate cancer (CaP) individuals, and further analyze its diagnostic value, prognostic significance, and regulatory role in CaP cells. METHODS:Serum was collected from individuals with CaP, benign prostatic hyperplasia (BPH), and healthy controls (HC). Paired tumor and adjacent normal tissues were obtained from CaP cases. miR-638 expression was determined by qRT-PCR. ROC curve was performed to evaluate the diagnostic efficacy of serum miR-638 alone and in combination with t-PSA. Spearman's rank was used to analyze the association between tissue miR-638 and clinicopathological features. Kaplan-Meier and multivariate Cox regression were used to identify prognostic factors. In vitro, CCK‑8, flow cytometry, and Transwell assays were performed to evaluate PC‑3 cell proliferation, apoptosis, migration, and invasion. RESULTS:miR-638 was significantly upregulated in the serum of CaP individuals compared with BPH and HC, presenting a stepwise upregulation trend. Combined detection of serum miR-638 and t-PSA significantly improved the diagnostic performance for CaP. High miR-638 expression in tumor tissues was closely associated with adverse clinicopathological parameters and predicted shorter overall survival. Multivariate Cox regression demonstrated that tissue miR-638 overexpression was an independent poor prognostic factor. In vitro assays demonstrated that miR-638 overexpression promoted the proliferation, migration, and invasion of PC-3 cells and inhibited cell apoptosis, while miR-638 knockdown reversed these malignant phenotypes. CONCLUSION:Aberrant upregulation of miR-638 in serum and tissues acts as a promising biomarker for CaP diagnosis and prognosis. miR-638 exerts oncogenic functions to facilitate CaP malignant progression.