IL-17A对肝细胞癌可溶性MICA表达的影响

Interleukin-17A enhances the production of soluble MICA by human hepatocellular carcinoma cells

目的:探讨患者外周血清白介素-17A(serum Interleukin-17A,IL-17A)对肝癌细胞可溶性MICA(soluble major histocompatibility complex class Ichain-related gene A,sMICA)的调控作用及可能机制.方法:收集慢性肝炎(chronic hepatitis,CH)、肝硬化(liver cirrhosis,LC)、HCC、健康对照者(healthcontrol,HC)各30例,采用ELISA方法分别检测血清sMICA及IL-17A的表达水平;HepG2和PLC/PRF/5细胞加入0、10、50ng/mL的重组人IL-17A(RhIL-17A)作用24h后,分别采用ELISA检测sMICA的表达;并在50ng/mL的RhIL-17A作用24h后,采用流式细胞术(flow cytometry,FCM)检测膜型MICA的表达、荧光定量RT-PCR检测MICA mRNA的表达、Western blot检测ADAM9,p65和磷酸化p65(P-p65)的表达.结果:HCC组血清IL-17A与sMICA水平明显高于CH、LC、HC组(IL-17AF=46.321,sMICAF=24.144,P<0.01),且二者呈正相关(r=0.28,P<0.01);RhIL-17A显著增加HCC细胞sMICA、膜MICA mRNA的表达(P<0.05),且可增加HCC细胞ADAM9和P-p65蛋白的表达.结论:IL-17A能上调肝癌细胞MICA mRNA表达,可能与其活化NF-B-ADAM9信号通路,从而增加HCC sMICA的表达有关.

AIM：To investigate the correlation between serum interleukin-17A （IL-17A） levels and soluble major histocompatibility complex class I chainrelated gene A （sMICA） in patients with chronic hepatitis （CH）, liver cirrhosis （LC）, or hepatocellular carcinoma （HCC）, and to discuss the role ofIL-17A in regulating the production of sMICA. METHODS：Serum samples were collected from healthy controls （HC） and patients with CH, LC, or HCC （n = 30 for each group）, and sMICA and IL-17A were assayed by enzyme-linked immunosorbent assay （ELISA）. PLC/PRF/5 and HepG2 cells were cultured with 0, 10 and 50 ng/mL of recombinant human IL-17A （RhIL-17A） for 24 h, and the expression of sMICA was detected by ELISA. Flow cytometry （FCM） and real-time quantitative polymerase chain reaction （qRT-PCR） were used to detect the expression of membrane MICA after HCC cells were incubated with 50 ng/mL RhIL-17A for 24 h. Western blot was used to detect the expression of ADAM9, p65 and phosphorylation-p65 （P-p65）. RESULTS：Serum IL-17A and sMICA levels were significantly higher in HCC patients than in those with HC, LC or HC （IL-17AF = 46.321, sMICA F = 24.144, P〈0.01）. IL-17A levels were positively associated with soluble MICA levels in hepatopathy patients （r = 0.28, P〈0.01）. Addition of RhIL-17A resulted in a significant increase in the production of sMICA and membrane MICA mRNAs in HepG2 and PLC/PRF/5 cells （all P〈0.05）, and RhIL-17A also increased the ADAM9 and P-p65 protein levels. CONCLUSION：IL-17A may up-regulate membrane MICA mRNA expression by activating the nuclear factor-kappa B （NF-B）-ADAM 9 signal pathway and thus enhance the production of sMICA by human HCC cells.