The expression of sex determining region Y-box 18 in prostate cancer and its impact on prostate cancer cell function

Abstract

Objective To explore the expression of sex determining region Y-box 18(SOX18) in prostate cancer(PCa) and its role on prostate cancer cells. Methods The expression of SOX18 in 98 PCa tissues and 81 adjacent non-tumor tissues was detected by immunohistochemistry. The expression of SOX18 mRNA and protein in PCa cell lines were detected by q-PCR and Western blotting analysis, respectively. After knocking down SOX18 with si-RNA, the proliferation, migration and invasion of PCa cells were analyzed by CCK8, Transwell and Matrigel assays in vitro. Results The rate of high SOX18 expression in prostate cancer tissues was 73.5% (72/98), which was higher than that in adjacent normal tissues (43.2%, 35/81)(P<0.01). In addition, the rates of high SOX18 expression in clinical stage III-IV [83.7%(36/43) vs. 65.5%(36/55), χ2=4.131, P=0.042], pathological grading G3-4 [88.6%(39/44) vs. 61.7%(33/54), χ2=9.424, P=0.002] and Gleason scores ≥8 [85.0%(34/40)vs. 65.0%(38/58), χ2=4.610, P=0.032] groups were higher than those in clinical stage III-IV, pathological grading G1-2 and Gleason scores ≤7 groups. However, there were no differences in the rate of high SOX18 expression in different age groups [77.3%(38/54) vs. 70.4%(34/44), χ2=0.539, P=0.441]. Knockdown of SOX18 notably suppressed the proliferation, migration and invasion of prostate cancer cells. Conclusions SOX18 is over-expressed in prostate cancer, and could promote the proliferation, migration and invasion ability of prostate cancer cells. Key words: Prostate cancer; Sex determining region Y-box 18(SOX18); Small interfering RNA; Cell proliferation; Cell migration