Diagnostic value of miR‑21 and miR‑221 as potential biomarkers for early diagnosis of prostate cancer

Prostate cancer (PCa) is globally the second most diagnosed malignancy in men, with >1.5 million new cases reported in 2020. Given the limitations of classical detection methods, the discovery of new predictive PCa biomarkers is critical. MicroRNAs (miRs), which are small, single-stranded, non-coding RNA molecules, have emerged as potential biomarkers for cancer diagnosis and prognosis. The present study aimed to evaluate the diagnostic value of miR-21 and miR-221 in PCa and their association with clinicopathological parameters. The expression of miR-21 and miR-221 was assessed using reverse transcription-quantitative PCR in 50 tumour and 50 control tissue samples. The results demonstrated that miR-21 and miR-221 were significantly upregulated in PCa tissues compared with that of the normal control tissues. Receiver operating characteristic curve analysis revealed that miR-21 had an area under the curve (AUC) of 0.90, with a sensitivity of 70% and a specificity of 96%. Similarly, miR-221 demonstrated an AUC of 0.89, with a sensitivity of 86% and a specificity of 78%. High expression of miR-21 and miR-221 was also demonstrated to be associated with higher Gleason scores and advanced tumour stages. The findings of the present study indicate the potential role of miR-21 and miR-221 as biomarkers in the diagnosis of PCa. However, further studies in non-invasive samples such as serum, blood and urine are needed to support the results of the present study.