Limited Study On The Relevance Of Proprotease ADAM17 And Its Upstream Convertases PC7 With The Growth Of Tumor Cells

Disintegrin metalloproteases (ADAMs) are found in recent years which belong to a class of matrix metalloproteinase binding to the cell membrane. So far we know that ADAM s family contains more than 40 members, the majority of them have metalloproteinase domain which can process TNF-a, EGFR receptors(such as EGF,HB-EGF), TNF receptorⅠa ndⅠ, ErbB2, ErbB4 receptors, APP and so on. They play an important role in the degradation of extracellular matrix, cell - cell adhesion, cell - matrix adhesion, cell fusion and signal transduction and other biological activity. There is an article published in Nature magazine in 2008 described the role of "signal pathway scissors" of ADAMs in the process of tumorigenesis and metastasis, and ADAM l0 and ADAM17 are two main members, they may promote tumor cell proliferation by hydrolysis processing of epidermal growth factor, transforming growth factor and so on. Preliminary study has shown that ADAM10,17 are transmembrane proteins in the form of precursors located at the plasma membrane and the negative Glogi body (trans face) membrane surface, they needs to be activated by upstream proprotein-converting enzyme before they start to function.Many peptides and protein precursors in the eukaryotic cells must be activated to be mature proteins before they play their functions. Proportion convertase is a kind of enzyme which has processing function, its family contains Furin,PC1/3, PC2, PC4, PC7/8/LPC, PACE, PC5/6 and so on. Their target moleculars include growth factor and its receptor such as TGF-β,growth factor HB-EGF,PDGF-A,PDGF-B; insulin-like growth factor and its receptor; integrin; ECM degradation enzymes such as MMP,MT-MMPs and ADAMs,ADAMTS and so on.Research reported has also shown that ADAM17 can promote cell proliferation in some tumor cell lines, and ADAM17 can be activated by furin while ADAM10 can be processed by both furin and PC7 . PC7 can identify the site RKKR of ADAM10, release N-terminal peptide sequence to make its precursor protein to become mature, so PC7 can be regarded as the main enzyme for activating ADAM10. Therefore, we speculate Furin, PC7 may play a role in the development process of tumor formation through the processing of the VEGF-C, IGF-I directly or via processing of ADAM10, A DAM17 indirectly. At present, we know that A DAM17 and PC7 showed high expression in breast cancer, ovarian cancer and some other tumor tissues. But whether and how they play roles in the process of tumor formation and metastasis need to be examined.So we intend to explore the relationship between A DAM17, PC7 and the proliferation of tumor cells. The plasmid of target PC7 gene and A DAM17 was constructed and transfected into cu1tured cancer cell lines with LIPOFECTAMINE 2000; Western blotting was used to detect the expression of PC7 and ADAM17 at the protein level. MTT assay and FACS was employed to detect the cell proliferation after transfection. Successfully constructed plasmid containing the target PC7 gene was confirmed by restriction enzyme digestion and DNA sequencing . The result of MTT and FACS indicates that ADAM17 can promote the proliferation of Hela cells, The results of MTT and FACS indicates that there is no effect on the proliferation of MCF-7 and Hela cells with PC7 transfection.