Department of Biochemistry and Molecular Biology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo 192-0392, Japan.
Int J Oncol. 2012 Jan;40(1):236-42. doi: 10.3892/ijo.2011.1224. Epub 2011 Oct 6.
EMMPRIN (extracellular matrix metalloproteinase inducer)/CD147, a membrane-bound glycoprotein with two extracellular loop domains (termed loops I and II), progresses tumor invasion and metastasis by increasing the production of matrix metalloproteinase (MMP) in peritumoral stoma cells. EMMPRIN has also been associated with the control of migration activity in some tumor cells, but little is known about how EMMPRIN regulates tumor cell migration. In the present study, EMMPRIN siRNA suppressed the gene expression and production of EMMPRIN in human uterine cervical carcinoma SKG-II cells. An in vitro scratch wound assay showed enhancement of migration of EMMPRIN-knockdown SKG-II cells. In addition, the SKG-II cell migration was augmented by adding an E. coli-expressed human EMMPRIN mutant with two extracellular loop domains (eEMP-I/II), which bound to the cell surface of SKG-II cells. However, eEMP-I/II suppressed the native EMMPRIN-mediated augmentation of proMMP-1/procollagenase-1 production in a co-culture of the SKG-II cells and human uterine cervical fibroblasts, indicating that the augmentation of SKG-II cell migration resulted from the interference of native EMMPRIN functions by eEMP-I/II on the cell surface. Furthermore, a systematic peptide screening method using nine synthetic EMMPRIN peptides coding the loop I and II domains (termed EM1-9) revealed that EM9 (170HIENLNMEADPGQYR184) facilitated SKG-II cell migration. Moreover, SKG-II cell migration was enhanced by administration of an antibody against EM9, but not EM1 which is a crucial site for the MMP inducible activity of EMMPRIN. Therefore, these results provide novel evidence that EMMPRIN on the cell surface limits the cell migration of human uterine cervical carcinoma cells through 170HIENLNMEADPGQYR184 in the loop II domain. Finally, these results should provide an increased understanding of the functions of EMMPRIN in malignant cervical carcinoma cells, and could contribute to the development of clinical strategies for cervical cancer therapy.
外泌体基质金属蛋白酶诱导因子(EMMPRIN)/CD147 是一种膜结合糖蛋白,具有两个细胞外环结构域(称为环 I 和 II),通过增加肿瘤周围基质细胞中基质金属蛋白酶(MMP)的产生来促进肿瘤的侵袭和转移。EMMPRIN 也与一些肿瘤细胞迁移活性的控制有关,但对于 EMMPRIN 如何调节肿瘤细胞迁移知之甚少。在本研究中,EMMPRIN siRNA 抑制了人子宫颈癌 SKG-II 细胞中 EMMPRIN 的基因表达和产生。体外划痕实验显示,EMMPRIN 敲低 SKG-II 细胞的迁移能力增强。此外,添加一个具有两个细胞外环结构域(eEMP-I/II)的大肠杆菌表达的人 EMMPRIN 突变体可增强 SKG-II 细胞的迁移,该突变体能与 SKG-II 细胞的细胞表面结合。然而,eEMP-I/II 抑制了 SKG-II 细胞与宫颈成纤维细胞共培养中天然 EMMPRIN 介导的 proMMP-1/胶原酶-1 产生的增加,表明 SKG-II 细胞迁移的增加是由于 eEMP-I/II 在细胞表面对天然 EMMPRIN 功能的干扰所致。此外,使用编码环 I 和 II 结构域的 9 个合成 EMMPRIN 肽(称为 EM1-9)的系统肽筛选方法表明,EM9(170HIENLNMEADPGQYR184)促进 SKG-II 细胞迁移。此外,用针对 EM9 的抗体处理可增强 SKG-II 细胞的迁移,但用针对 EM1 的抗体处理不能增强 EM1,而 EM1 是 EMMPRIN 诱导 MMP 活性的关键位点。因此,这些结果提供了新的证据,表明细胞表面的 EMMPRIN 通过环 II 结构域中的 170HIENLNMEADPGQYR184 限制人子宫颈癌细胞的迁移。最后,这些结果应该为恶性宫颈癌细胞中 EMMPRIN 的功能提供更深入的了解,并有助于开发宫颈癌治疗的临床策略。