低氧诱导因子1α通过调控CXCR4表达促进结肠癌转移  

HIF1α induces metastasis of colon cancer by upregulating CXCR4 expression

作　　者：刘文 张玉青 LIU Wen;ZHANG Yuqing(Department of Cadre Health and Geriatric Medicine,Second Hospital of Shandong University,Jinan 250033,Shandong Province,China;Department of Ultrasonics,Medical Imaging Center,Second Hospital of Shandong University,Jinan 250033,Shandong Province,China)

机构地区：[1]山东大学第二医院干部保健/老年医学科,山东济南250033 [2]山东大学第二医院医学影像中心超声科,山东济南250033

出　　处：《肿瘤》2019年第11期908-915,923,共9页Tumor

基　　金：山东大学第二医院科研基金青年基金(编号：Y2015010012)~~

摘　　要：目的:探究低氧诱导因子1α(hypoxia inducible factor 1α,HIF1α)与结肠癌侵袭转移的关系。方法:在低氧状态下培养结肠癌LoVo及HCT116细胞,然后采用Transwell小室法检测细胞侵袭能力的改变,并用蛋白质印迹法检测细胞中HIF1α、C-X-C趋化因子受体4(C-X-C chemokine receptor 4,CXCR4)、SRC及磷酸化SRC(phosphorylated SRC,p-SRC)的表达情况。采用免疫组织化学法检测59例结肠癌组织中HIF1α和CXCR4蛋白的表达,并分析HIF1α表达与结肠癌患者临床病理特征的相关性。通过实时荧光定量PCR检测CXCR4转录水平与低氧之间的关系,并采用免疫共沉淀实验验证HIF1α与CXCR4的转录调节因子核受体辅激活蛋白1(nuclear receptor coactivator 1,Ncoa1)之间的结合作用。结果:低氧培养后结肠癌LoVo及HCT116细胞的侵袭能力明显增强(P值均<0.01)。在低氧条件下,LoVo和HCT116细胞中HIF1α表达水平明显升高(P值均<0.01),同时CXCR4表达及其下游通路蛋白SRC的活化水平明显上调(P值均<0.01)。59例结肠癌患者的HIF1α表达与肿瘤TNM分期、淋巴结转移及远处转移均具有明显相关性(r值分别为0.69、0.71和0.64,P值均<0.01),而且CXCR4与HIF1α表达之间呈明显正相关性(r=0.75,P <0.001)。低氧状态下CXCR4转录水平明显上调(P <0.01),HIF1α能够与CXCR4的转录调节因子Ncoa1结合;而在干扰Ncoa1表达后,HIF1α与Ncoa1的结合消失,低氧状态下CXCR4的转录水平与常氧对照组相比无明显差异(P> 0.05)。结论:低氧状态下结肠癌LoVo和HCT116细胞的侵袭能力增强,HIF1α表达水平明显升高。结肠癌组织中HIF1α表达水平与结肠癌患者的肿瘤分期和转移存在正相关性。HIF1α可能通过结合并激活转录因子Ncoa1,调控CXCR4表达,从而促进结肠癌细胞侵袭及肿瘤转移。Objective: To investigate the role of hypoxia inducible factor 1 α (HIF1α) in the invasion and metastasis of human colon cancer.Methods: Human colon cancer LoVo and HCT116 cells were cultured under hypoxia, then the cell invasiveness was detected by Transwell chamber assay, and the expression levels of HIF1α, C-X-C chemokine receptor 4(CXCR4), SRC and phosphorylated SRC(p-SRC) were detected by Western blotting. The expressions of HIF1α and CXCR4 in 59 cases of colon cancer were detected by immunohistochemical method, and the correlation between the expression of HIF1α and the clinicopathological characteristics of colon cancer patients was analyzed. The relationship between CXCR4 transcription and hypoxia was revealed by realtime fluorescent quantitative PCR, and the interaction between HIF1α and nuclear receptor coactivator 1(Ncoa1), a transcription regulation factor of CXCR4, was cofirmed by coimmunoprecipitation assay.Results: The invasiveness ability of colon cancer LoVo and HCT116 cells was significantly enhanced under hypoxia(both P < 0.01). The expression level of HIF1α was significantly increased in LoVo and HCT116 cells under hypoxia(both P < 0.01), while the expressions of CXCR4 and p-SRC were increased significantly(all P < 0.01). The positive expression of HIF1αwas significantly correlated with TNM stage, lymph node metastasis, and distant metastasis in 59 patients with colon cancer(r = 0.69, 0.71, 0.64, respectively;all P < 0.01), while CXCR4 expression was positively correlated with HIF1α expression(r = 0.75, P < 0.001). The transcription of CXCR4 was upregulated in LoVo cells under hypoxia(P < 0.01), and HIF1αcould bind to Ncoa1, a transcription regulator of CXCR4. When the expression of Ncoa 1 gene was interfered by siRNA, the interaction of HIF1α and Ncoa1 was disappeared, meanwhile the transcription of CXCR4 in LoVo cells under hypoxia showed no difference compared with the normal control group(P > 0.05).Conclusion: Under hypoxia, the expression level of HIF1α is upregulated in the c

关 键 词：结肠肿瘤 低氧诱导因子1 肿瘤侵润 受体 趋化因子C-X-C4 

分 类 号：R735.35[医药卫生—肿瘤]