Objective: To explore the expression of miR-132 in prostate cancer and its effects on the growth and invasiveness of prostate cancer cells and the influence of hypoxia on the level of miR-132 and biological behavior of prostate cancer cells.
Methods: Real time PCR was used to measure the expression level of miR-132 in the prostate cancer tissue, analyze its relationship with the clinical stage and Gleason score of prostate cancer, and determine the influence of hypoxia on the miR-132 level in the human prostate cancer PC3 cell line in vitro. Sulfor-hodamine B chromatometry and Matrigel invasion assay were employed to detect the effects of hypoxia and miR-132 mimic plasmid transfection on the viability and invasiveness of PC3 cells in vitro.
Results: The miR-132 level in the prostate cancer was significantly declined to 52.38% (in T1－T2 stages) and 21.59% (in T3－T4 stages) of that in the cancer-adjacent tissue (both P<0.01). In hypoxia, the expression of miR-132 was significantly decreased in the PC3 cells (P<0.01). After 48 and 72 hours of transfection with miR-132 mimic plasmid, the viability of the PC3 cells was markedly reduced (P<0.05 or P<0.01), and their invasiveness decreased by 57.5% after 48 hours (P<0.01). However, there was no significant difference in the viability or invasiveness of the PC3 cells transfected with miR-132 mimic plasmid between normoxia and hypoxia.
Conclusions: The reduced expression of miR-132 is closely related to the clinical stage and Gleason score of prostate cancer. Hypoxia increases the viability and invasiveness of prostate cancer cells in vitro by down-regulating the expression of miR-132 and consequently may promote the growth and metastasis of prostate cancer.
目的： 探讨miR-132在前列腺癌中的表达及其对前列腺癌细胞生长和侵袭的调节作用，以及缺氧条件下前列腺癌细胞中miR-132水平的变化及其生物学行为的改变。方法： 荧光定量PCR分析前列腺癌组织中miR-132的表达水平，分析其与临床分期和Gleason评分的关系，及体外缺氧对人前列腺癌细胞株PC3中miR-132表达的影响；磺酰罗丹明B（SRB）比色法和Matrigel侵袭实验分别检测缺氧和miR-132 mimic质粒转染对PC3细胞活力和侵袭的体外影响。结果： 相对于对照组癌旁组织，前列腺癌组织中miR-132水平降低至对照组的52.38%（T1~T2期）（P<0.01）和21.59%（T3~T4期）（P<0.01）。缺氧培养下，PC3细胞的miR-132水平明显降低（P<0.01）。miR-132 mimic质粒转染48 h和72 h后，PC3细胞活力显著降低（P<0.05或P<0.01）；转染后48 h，PC3细胞侵袭力降低了57.5%（P<0.01）。然而，miR-132 mimic质粒转染PC3细胞后，常氧和缺氧培养两种方式间的细胞活力和侵袭力均无明显差异(P>0.05)。 结论： miR-132的表达降低与前列腺癌的临床分期和Gleason评分密切相关；缺氧通过下调miR-132表达，可在体外促进前列腺癌细胞的活力和侵袭，可能进一步促进前列腺癌的生长和转移。.
Keywords: growth; hypoxia; invasion; miR-132; prostate cancer.