胰岛素受体底物1低表达促进头颈部鳞状细胞癌的侵袭转移

目的:研究胰岛素受体底物1(insulin receptor substrate 1,IRS-1)在头颈部鳞状细胞癌( head and neck squamous cell carcinoma,HNSCC)侵袭转移中的作用及其可能的机制.方法:应用定量RT-PCR法检测HNSCC患者淋巴结转移灶和原发灶癌组织中IRS-1 mRNA的表达,以及不同转移能力头颈部肿瘤细胞株上IRS-1 mRNA的表达.用Taqman探针法检测miR-9及U6的相对表达量.利用小干扰RNA技术阻抑IRS-1表达,肿瘤细胞侵袭实验检测IRS-1干扰前后对细胞侵袭能力的影响.用定量RT-PCR和Western blot检测上皮－间叶转化(epithelial-mesenchymal transition,EMT)的标志物E-cadherin及vimentin mRNA和蛋白的表达;用SRB法检测细胞存活率.结果:(1) HNSCC患者淋巴结转移灶中IRS-1 mRNA的表达低于原发灶(P＜0.05);高转移性HNSCC细胞株中IRS-1mRNA的表达低于低转移性细胞株(P＜0.05).(2)下调IRS-1表达,肿瘤细胞的侵袭能力增强,上皮间叶转化标志物E-cadherin表达下降,同时伴有miR-9表达的升高.结论:IRS-1低表达可能通过上皮间叶转化和上调miR-9而增强细胞的侵袭能力,促进HNSCC的转移.

The role of downregulation of insulin receptor substrate 1 in the invasion and metastasis of head and neck squamous cell carcinoma

AIM: To explore the role of insulin receptor substrate 1(IRS-1) in the invasion and metastasis of head and neck squamous cell carcinoma(HNSCC) and potential mechanism.METHODS:IRS-1 mRNA expression in the metastatic lymph node and corresponding primary tumour tissues of HNSCC patients,in highly and poorly metastatic HNSCC cells were detected by qRT-PCR.miR-9 and U6 expression were measured by the TaqMan microRNA qPCR.IRS-1 expression was downregulated by using siRNA.The effect of IRS-1 on cell invasive potency was examined by transwell invasion assay after IRS-1 interference.E-cadherin and vimentin were detected by qRT-PCR and Western blot.Cell survival rate was examined by SRB assay. RESULTS:IRS-1 mRNA expression decreased in the metastatic lymph node tumor tissues compared to primary tumor tissues of HNSCC patients(P<0.05).As well,its expression levels were lower in highly metastatic HNSCC cells compared to its parental poorly metastatic cells(P<0.05).IRS-1 knockdown promoted invasion of poorly metastatic 686LN cells and induced EMT in parallel with upregulation of miR-9 expression. CONCLUSION: Downregulation of IRS-1 may promote invasion and metastasis of head and neck squamous cell carcinoma by epithelial-mesenchymal transition and upregulating miR-9 expression.