Cyclophilin A Is Associated With The Growt And Metastatic Potential In Human Non-small Cell Lung Cancer Cells

IntroductionLung cancer is the leading cause of cancer deaths in worldwide,the five-year survival rate is only 8.9%～15%. In China, 600,000 cases died of lung cancer annually. Lung cancer is divided into two types in morphology: non–small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) , 85% of them are NSCLC. The development of lung cancer is a process of multiple factors in which environmental and genetic play important roles. With the progress of proteomics many proteins are found which involve in the progression of lung cancer. CypA is one of them.Cyclophilins is a family of peptidyl-prolyl cis-trans isomerase (Peptidyl-prolyl cis-trans isomeras, PPIase). CypA is the most important member of cyclophilins which involves in catalyzes protein folding , assembling and transporting. It is well known that CypA overexpresses in many cancers, but its role in lung cancer are unclear.The purpose of this reseach was to investgate the functions of differential expression levels of CypA in the growth and metastatic potential of NSCLC and seek the mechanism. Materials and MethodsIn order to invesgate the differential expression of CypA, we use Real-time PCR to test the mRNA levelof CypA in lung cancer cell lines and human embryo lung fibroblast line. Then we use the CypA-targeting lentivirus- mediated RNA interference approach in 95C and A549 cell lines. To test the growth of cells we use MTS assay, colony formation experiment, anchorage-independent growth assay. To test the migration and invansion of cells we use wound healing assay and transwell unit. The activity of secreted matrix metalloproteinase (MMP) 2,9 were detected by gelatin zymography .ResultsThe CypA mRNA expression in various lung cancer cell lines was significantly higher than normal human embryo lung fibroblast. After infected with the CypA-targeting lentivirus- mediated RNA interference , the mRNA and protein expression levels of CypA in 95C and A549 cells were significantly decreased . Knockdown CypA in both 95C and A549 resulted in inhibition of cell growth. This was the first time to find out that knockdown CypA in both 95C and A549 resulted in inhibition of cell metastasis.The activities of secreted MMP9 in 95C and A549 cells was positive correlated with the expression of CypA , while the activities of secreted MMP2 has no such correlation.ConclusionCypA overexpressed in a variety of lung cancer cell lines. CypA improved the growing and metastatic potential which including the proliferation, suppression of density-dependent inhibition of growth, tumorigenesis, migration and invansion potential of NSCLC. Furthermore, MMP9 activities may be related to the regulation of metastasis which caused by CypA in NSCLC.