蛋白磷酸酶2A的癌性抑制因子在前列腺癌细胞增殖、凋亡和侵袭中的作用

Role of cancerous inhibitor of protein phosphatase 2A in proliferation, apoptosis and invasion of prostate cancercells

目的 观察蛋白磷酸酶2A的癌性抑制因子(CIP2A)在前列腺癌细胞增殖、凋亡和侵袭中的作用。方法 收集石家庄市第一医院确诊的前列腺癌组织83例和前列腺增生组织67例,检测两种组织中CIP2A表达,分析前列腺癌组织中CIP2A表达水平与临床病理特征关系;将人前列腺癌细胞株LNCAP随机分为研究组及对照组,给予研究组CIP2A基因抑制处理,对照组不作特殊处理,检测两组细胞中CIP2A蛋白、mRNA相对表达水平、细胞增殖、细胞周期分布、细胞侵袭能力。结果 前列腺癌组织中CIP2A蛋白阳性表达率为65.06%,明显高于前列腺增生组织的26.87%(P<0.01);年龄不同的患者癌组织中CIP2A蛋白表达水平比较差异无统计学意义(P>0.05);术后1年复发情况、病理组织分化程度、TNM分期及术前前列腺特异抗原(PSA)水平有关不同的患者癌组织中CIP2A蛋白表达水平差异有统计学意义(P<0.05);研究组细胞CIP2A mRNA相对表达水平明显低于对照组(P<0.01);研究组前列腺癌细胞增殖率为(93.37±4.23)%,明显低于对照组的(137.56±4.19)%(P<0.01);研究组G1期细胞占比(58.74±2.68)%,明显高于对照组的(49.82±2.70)%(P<0.01);研究组S期细胞占比(11.93±1.41)%,明显低于对照组的(22.06±2.13)%(P<0.01);研究组前列腺癌细胞穿膜细胞数为(92.83±8.50)个,明显低于对照组的(142.69±16.08)个(P<0.01)。结论 CIP2A在前列腺癌组织中呈高表达;CIP2A表达水平与患者术后复发、病理组织分化程度、TNM分期及术前PSA水平有关;CIP2A能促进前列腺癌细胞增殖、侵袭,并在其调亡过程中起重要作用。

Objective To investigate the role of cancerous inhibitor of protein phosphatase 2A (CIP2A) in proliferation, apoptosis and invasion of prostate cancer cells.Methods In this study, the expression level of CIP2A in tissues of prostate cancer (n=83) and benign prostatic hyperplasia (n=67) diagnosed in our hospital from May 2012 to September 2014 was detected, thereafter, the relationship between CIP2A expression level and clinicopathological features in prostate cancer tissues was analyzed. The human prostate cancer cell line LNCaP were divided into study group (silencing the CIP2A gene) and control group (no treatment) according to the different treatment methods. Then various indexes were detected by various methods, including expression levels of CIP2A protein and mRNA by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR), cell proliferation by methyl thiazol tetrazolium (MTT) colorimetry, cell cycle distribution by flow cytometry, and cell invasion ability by Transwell TM assay.Results The positive expression rate of CIP2A protein in prostate cancer tissues was significantly higher than that in benign prostatic hyperplasia tissues (65.06% vs. 26.87%, P<0.01). The expression level of CIP2A protein was not correlated with the age (P>0.05), but was correlated with the postoperative-1-year recurrence rate, pathological differentiation, TNM staging and preoperative prostate specific antigen (PSA) levels (P<0.05);The relative expression level of CIP2A protein and mRNA in the study group was significantly lower than that in the control group (P<0.05). The proliferation rate of prostate cancer cells in the study group was significantly lower than that in the control group [ (93.37±4.23)% vs. (137.56±4.19)%, P<0.01];The proportion of cells in G1 phase of the study group was significantly higher than that of the control group [ (58.74±2.68)% vs. (49.82±2.70)%, P<0.01];The proportion of cells in S phase of the study group was significantly lower than that of the control group [ (11.93±1.41)% vs. (22.06±2.13)%, P<0.01];The number of transmembrane cells in the prostate cancer cells of the study group was significantly lower than that of the control group [ (92.83±8.50) vs. (142.69±16.08), P<0.01].Conclusion CIP2A is highly expressed in prostate cancer tissues, and is related to postoperative recurrence, pathological differentiation, TNM staging and preoperative PSA levels;The study shows that CIP2A can promote prostate cancer cell proliferation, and invasion, as well as plays an important role in the process of apoptosis.