Comparative miRNA Expression Profiling Reveals Candidates Involved in Prostate Cancer Radioresistance

Prostate cancer is the most common malignancy among men worldwide, and treatment response depends on tumor radiosensitivity. Micrornas (mirnas) are key regulators of cell proliferation, apoptosis, and dna damage response, and have been implicated in therapy resistance. However, their roles in prostate cancer radioresponse remain incompletely understood. This study investigated the expression patterns of ten selected mirnas associated with radiation resistance in other cancers in prostate cancer models. Radiation-resistant pc-3, radiation-sensitive lncap, and normal prostate epithelial (hprec) cells were exposed to 0, 2, 4, 6, and 8 gy of ionizing radiation. Mirna expression levels were analyzed by quantitative pcr using snord48 as an internal control and calculated with the 2 - δδct method. In pc-3 cells, mir-20a-5p, mir-128-3p, and mir-135b-5p showed significant dose-dependent upregulation, whereas mir-23b-3p and mir-381-3p were downregulated. Mir-128-3p correlated positively with radiation dose, while mir-23b-3p and mir-381-3p showed negative correlations. Lncap cells exhibited moderate, non-dose-dependent mirna changes. Distinct mirna signatures differentiate radiation-resistant and radiation-sensitive prostate cancer cells. Mir-20a-5p, mir-128-3p, and mir-135b-5p may contribute to radioresistance, whereas mir-23b-3p and mir-381-3p may act as radiosensitizers.