肌动蛋白相关蛋白2/3复合体4在结直肠癌组织中的表达及其对侵袭能力的影响

Expression of actin related protein 2/3 complex 4 in colorectal cancer and its effect on invasion ability

目的观察肌动蛋白相关蛋白2/3复合体4(ARPC4)在结直肠癌组织、癌旁组织中的表达情况,分析ARPC4蛋白的表达变化与结直肠癌患者临床病理指标及预后的关系。方法应用实时荧光定量PCR和Western blot检测肿瘤组织和癌旁组织中ARPC4的mRNA及蛋白表达情况,应用免疫组织化学检测ARPC4在110例结肠癌患者的结肠癌组织和癌旁组织中的表达情况;分析ARPC4蛋白的表达与结直肠癌患者临床病理指标及预后的关系。采用Transwell法检测结直肠癌细胞系HCT-8中ARPC4敲降后细胞侵袭能力的变化;应用Western blot研究ARPC4影响结直肠癌细胞侵袭相关蛋白,分析ARPC4影响结直肠癌细胞侵袭能力的分子机制。结果实时荧光定量PCR和Western blot的结果显示,ARPC4在结肠癌组织中表达明显高于癌旁组织(P<0.01)。免疫组织化学的结果显示,ARPC4蛋白在结直肠癌组织中的阳性表达率明显高于癌旁组织(59%vs.12%,P<0.01)。ARPC4蛋白在结直肠癌组织中的表达与肿瘤淋巴结转移、远处转移及病理分期有关(P<0.05)。Kaplan-Meier生存分析结果显示,ARPC4蛋白阳性表达可明显缩短结直肠癌患者术后无瘤生存期(P=0.010)。多因素Cox回归分析结果表明,ARPC4蛋白阳性表达是结直肠癌患者预后不良的独立预测因素(P=0.035)。下调ARPC4表达能够抑制HCT-8的侵袭,Western blot结果显示在HCT-8中ARPC4敲降后,侵袭相关蛋白基质金属蛋白酶(MMP)-2、MMP-9表达受到抑制。结论 ARPC4蛋白在结直肠癌中高表达,并与结直肠癌的转移及预后相关,ARPC4可能通过MMP-2和MMP-9影响结直肠癌细胞侵袭。

Objective To observe the expression of actin related protein 2/3 complex 4(ARPC4)in colorectal cancer(CRC)tissue and paracancerous tissue,and to analyze the relationship between ARPC4 protein expression and clinicopathological parameters and prognosis of colorectal cancer patients.Methods Real-time fluorescence quantitative PCR(q-PCR)and western blot were used to detect the expressions of ARPC4 mRNA and protein in tumor tissues and normal paracancerous tissues.Expressions of ARPC4 in colorectal cancer tissue and paracancerous tissue in 110 cases of colorectal cancer was determined by using the immunohistochemistry(IHC)technique.The relationship between ARPC4 expression with clinicopathological indexes and prognosis was analyzed.The Transwell assay was used to detect the cell invasion ability of HCT-8 cell lines after ARPC4 knock down.Western blot was used to detect the expressions of ARPC4 on colorectal cancer cell invasion,and the molecular mechanism of ARPC 4 affecting CRC cell invasion ability was investigated.Results The q-PCR and western blot results showed that expression of ARPC4 in CRC tissue was significantly higher than that in adjacent normal tissue(P<0.01).The IHC results showed that positive expression rate of ARPC4 protein in CRC tissue was 59%,which was significantly higher than 12%in the paracancerous tissue(P<0.01).The expression of ARPC4 protein in CRC tissue was correlated with lymph node metastasis,distal metastasis and pathological stage(P<0.05).The Kaplan-Meier survival analysis results revealed that the ARPC4 protein positive expression significantly shortened the postoperative tumor-free survival period(P=0.010).The multi-factor Cox regression analysis results showed that the ARPC4 protein positive expression was an independent prognosis factor in the patients with CRC(P=0.035).The invasion ability in HCT-8 cells was inhibited through RNAi-mediated ARPC4 downregulation.The western blot analysis showed that MMP-2 and MMP-9 expression was inhibited after ARPC4 knockdown in HCT-8 cells.Conclusion ARPC4 protein is highly expressed in CRC,and is associated with metastasis and prognosis.ARPC4 might affect colorectal cancer cell invasion possibly through MMP2 and MMP9.