Development of molecular targeting drugs for anti-metastasis and anti-drug resistance of tumor cells

细胞外基质金属蛋白酶诱导物(EMMPRIN)/CD147在多种肿瘤细胞表面高表达，并通过增加基质金属蛋白酶(MMPs)的产生而密切参与肿瘤细胞的侵袭。除了对基质金属蛋白酶的诱导活性外，细胞表面的EMMPRIN还与人肺癌细胞和人子宫内膜上的原基质金属蛋白酶-1/胶原酶-1结合，但其复合体的意义尚不清楚。在本研究中，我们明确了EMMPRIN在人宫颈癌SKG-II细胞上既能与原基质金属蛋白酶-1结合，又能与活性基质金属蛋白酶-1结合，但不能与包括基质金属蛋白酶-2、-3和-13在内的其他基质金属蛋白酶结合。这种结合被一个嵌合体蛋白有效地干扰，该嵌合体蛋白的铰链区被MMP13所取代，表明MMP1的铰链区是MMP1与EMMPRIN结合所必需的。ProMMPs的激活剂纤溶酶可激活与EMMPRIN结合的proMMP1。当活化的基质金属蛋白酶-1通过EMMPRIN结合到SKG-II细胞表面时，与对照组和原基质金属蛋白酶-1结合的细胞相比，细胞通过I型胶原胶的侵袭活性增强。MMP1的多肽(17mer)铰链区可有效干扰活性MMP1和原MMP1与SKG-II细胞的结合及其I型胶原胶的侵袭活性。因此，EMMPRIN通过形成基质金属蛋白酶-1-EMMPRIN复合体和诱导原MMPs，密切参与癌细胞的侵袭。此外，铰链区多肽可能是干扰基质金属蛋白酶-1-EMMPRIN功能的有用工具。

Extracellular matrix metalloproteinase inducer (EMMPRIN)/CD147 is highly expressed on the cell surface of various tumors, and closely participates in the tumor cell invasion by augmenting matrix metalloproteinase (MMP) production. In addition to the MMP-inducible activity, the cell surface EMMPRIN binds to proMMP-1/collagenase-1 on human lung carcinoma cells and human endometrium, but the significance of EMMPRIN-MMP-1 complex has not been clarified. In the present study, we clarified that EMMPRIN bind to both proMMP-1 and active MMP-1, but not other MMPs including MMPs-2, -3, and -13 on human uterine cervical carcinoma SKG-II cells. This binding was effectively interfered by a chimera protein of which hinge region was substituted by that of MMP-13, indicating that the hinge region of MMP-1 was essential for MMP-1 binding to EMMPRIN. The proMMP-1 bound to EMMPRIN was activated by plasmin, an activator of proMMPs. When the active MMP-1 bound to cell surface of SKG-II cells via EMMPRIN, the invasive activity of cells through type I-collagen gel was enhanced as compared control and proMMP-1 bound cells. The hinge region of peptide (17 mer) of MMP-1 effectively interfered with the binding of active MMP-1 as well as proMMP-1 to SKG-II cells and their type I collagen gel invasive activity. Therefore EMMPRIN is closely participates in the cancer cell invasion by forming MMP-1-EMMPRIN complex as well as induction of proMMPs. In addition, the hinge region peptide may be a useful tool for interfering with the function of MMP-1-EMMPRIN.