Targeting survivin using a combination of miR-494 and survivin shRNA has synergistic effects on the suppression of prostate cancer growth

Castration-resistant prostate cancer (CRPC) remains an obstacle in the current treatment provided for prostate cancer (PCa). Survivin, an apoptosis inhibitor, has been found to be involved in the progression of PCa, and is a promising candidate target for CRPC therapy. Micro (mi)RNAs are involved in the progression of PCa through the regulation of multiple genes. One of the objectives of the present study was to investigate the effect of miRNA (miR)‑494 on the expression of survivin, as well as on PCa growth. The present study also aimed to assess whether co-transfecting miR‑494 with survivin short hairpin (sh)RNA has synergistic effects on suppressing PCa proliferation or the expression of survivin. Gene Expression Omnibus datasets with clinical PCa miRNA expression profiles were utilized to analysis the expression of miR‑494 in Ca, compared with normal prostate samples. PC3 cells, a CRPC cell line, were transfected with either an miR‑494 expression adenovirus, a survivin shRNA adenovirus or the two together, to examine their effect on PCa growth and the expression of survivin in vitro and in vivo. miR‑494 was downregulated in PCa tissue samples and in the PC‑3 cell line. miR‑494 targeted survivin at the translational level in PCa. Overexpression of miR‑494 and silencing survivin RNA through the use of survivin shRNA inhibited the expression of survivin and attenuated PC‑3 cell growth in vitro and in vivo. Notably, co‑transfecting miR‑494 with survivin shRNA had synergistic effects on suppressing prostate cancer proliferation via further suppression of the expression of survivin. These results suggested that using multiple methods to inhibit the function of survivin may have improved efficacy for treating PCa.