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B7-H1是一种重要的负性共刺激分子,在肿瘤免疫逃逸中发挥重要作用,而微小RNA具有直接的转录后调控作用。本文研究miR-570对B7-H1表达的调控作用。首先将miR-570及其抑制剂anti-miR-570分别转染B7-H1表达阳性的人胃癌细胞SGC-7901和B7-H1表达阴性的人乳腺癌细胞MDA-MB-435,以流式细胞术检测B7-H1分子表达情况;然后构建pcDNA/B7-H1表达质粒与miR-570共转染CHO细胞,以流式细胞术检测CHO细胞上B7-H1分子的表达情况;最后分别构建含B7-H1基因3-UTR片段和含miR-570作用靶点序列的荧光素酶表达载体与miR-570共转染CHO细胞,用双荧光素酶报告系统检测荧光素酶活性。结果显示miR-570能显著抑制SGC-7901细胞和B7-H1基因转染细胞膜上B7-H1蛋白的表达,并能显著抑制荧光素酶表达载体表达的荧光素酶蛋白,而且anti-miR-570能上调MDA-MB-435细胞上B7-H1表达。本研究证明miR-570能显著抑制B7-H1蛋白表达,为通过抑制B7-H1信号通路以增强机体抗肿瘤免疫力的治疗途径奠定了基础。
B7-H1 is an important negative co-stimulatory molecule, plays an important role in tumor immune escape, and microRNA has a direct post-transcriptional regulation. In this paper, miR-570 on the regulation of B7-H1 expression. First, miR-570 and its inhibitor anti-miR-570 were transfected into human gastric cancer cell lines SGC-7901 and MDA-MB-435 with negative expression of B7-H1 respectively. The expression of B7-H1 was detected by flow cytometry. The expression of B7-H1 in CHO cells was detected by flow cytometry. Finally, the expression of B7- The 3’-UTR fragment of -H1 gene and luciferase expression vector containing miR-570 target sequence and miR-570 were co-transfected into CHO cells. The luciferase activity was detected by dual luciferase reporter system. The results showed that miR-570 significantly inhibited the expression of B7-H1 protein in the cell membrane of SGC-7901 cells and B7-H1 gene transfected cells, and significantly inhibited the luciferase protein expression of luciferase expression vector, and the anti-miR-570 Can up-regulate B7-H1 expression on MDA-MB-435 cells. This study demonstrated that miR-570 can significantly inhibit the expression of B7-H1 protein, which lays the foundation for the treatment of the anti-tumor immunity by inhibiting the B7-H1 signaling pathway.