Enzymatic inhibition of MICA sheddase ADAM17 by lomofungin in hepatocellular carcinoma cells
Enzymatic inhibition of MICA sheddase ADAM17 by lomofungin in hepatocellular carcinoma cells
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DOI：
10.1002/ijc.31615
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发表时间：
2018-11-15
影响因子：
6.4
通讯作者：
Kato, Naoya
中科院分区：
文献类型：
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作者：
Arai, Jun;Goto, Kaku;Kato, Naoya
在我们先前对慢性肝炎患者肝细胞癌易感基因的研究中，我们确定了MHC-I类多肽相关序列A(MICA)。自然杀伤细胞通过抑制MICA的脱落来清除包括肝癌在内的各种癌细胞。因此，我们研究了用于肝癌免疫治疗的MICA脱落酶和抑制剂。本研究以去整合素和金属蛋白水解酶(ADAMS)和基质金属蛋白水解酶的siRNA作用于人肝癌细胞株HepG2、PLC/PRF/5和Hep3B细胞，用ELISA法测定细胞内可溶性MICA(SmICA)的浓度，以确定治疗靶点。此外，FDA批准的药物文库在体外药物筛选试验系统中测试了对靶向酶的酶抑制作用。ADAM17基因敲除可降低肝癌细胞SMICA水平，增加膜结合型MICA(MMICA)表达。在使用FDA批准的药库进行的体外药物筛选中，发现抗真菌药物洛莫芬净可显著降低ADAM17的活性。在肝癌细胞中，mMICA的表达被诱导，SMICA的产生被抑制，并呈剂量依赖关系。这些作用在ADAM17被敲除后被取消，这表明罗莫芬菌素针对ADAM17。对罗莫芬净类似物的分析揭示了负责的官能团。综上所述，我们建议洛莫芬净通过抑制ADAM17而成为一种有吸引力的肝癌免疫控制药物。
In our previous study on hepatocellular carcinoma (HCC) susceptibility genes in chronic hepatitis patients, we identified the MHC class I polypeptide-related sequence A (MICA). Natural killer cells eliminate various cancer cells, including HCC, by suppressing MICA shedding. Therefore, we investigated MICA sheddases and inhibitors for HCC immunotherapy. In this study, HepG2, PLC/PRF/5, and Hep3B were treated with the siRNA of a disintegrin and metalloproteases (ADAMs) and matrix metalloproteases to measure the concentration of soluble MICA (sMICA) by ELISA to detect the therapeutic target. Furthermore, an FDA-approved drug library was tested for the enzymatic inhibition of the targeted enzyme in an in vitro drug screening assay system. ADAM17 knockdown reduced sMICA levels and increased membrane-bound MICA (mMICA) expression in HCC cells. In an in vitro drug screen using an FDA-approved drug library, lomofungin, an antifungal drug, was found to strongly decrease ADAM17 activity. In HCC cells, mMICA expression was induced and sMICA production was inhibited in a dose-dependent manner. These effects were cancelled upon ADAM17 knockdown, suggesting that lomofungin targeted ADAM17. Analysis of lomofungin analogs revealed the responsible functional groups. In summary, we suggest lomofungin to be an attractive agent for the immunological control of HCC, via the suppression of ADAM17.