Study On The Regulatory Mechanisms Of Mitochondrial Gene ND1 And ND3 In Colorectal Cancer

Mitochondria are the main sites of aerobic respiration, the Adenosine Triphosphate (ATP) which produced by oxidative phosphorylation is the major energy source for life activity. In recent years, some research results suggested that the structure of mitochondrial genes ND1 and ND3 have a significantly different between colorectal cancer and tumor-adjacent tissues. The protein subunits of ND1 and ND3 have involved in the crucial links of oxidative phosphorylation, which acted as the important part of respiratory chain Complex I. Gene mutations caused cellular metabolic disorder in respiration chain, leading to the incidence of cancer. These observations strongly suggest that mitochondrial ND1 and ND3 possibly participate in the regulation of colorectal cancer, while the specific molecular mechanism of cellular regulation is still unknown.This study respectively on a cellular level and organizational level compared the human colorectal cancer cells and normal intestinal epithelial cells, colorectal cancer tissues to the adjacent, Found the differences of ND1 and ND3 in the transcription and protein expression level。And selected HT29 and HCT116 from 5 strains of colorectal cancer cells as the main object for study。Using the SiRNA interference methods do some experiments in HT29 and HCT16 to down-regulate of ND1 and ND3 gene The results of MTS experimental show that down-regulate NDl or ND3 there is a decrease in the cell proliferation activity. Western Blot results show that down-regulating ND1 or ND3, protein PGCla and COXIV expression is cut and raised, And the protein expression of ND1 and ND3 are mutual influence between themselves。Application of BrdU and PI staining combined with FSC test results show group Si ND1 or ND3 have a proliferation hysteresis Compared with the NC group in 20 to 24 hours。Si ND1 and ND3 together at the same time the result shows cell G0/G1 phase increased, and proliferation cycle obviously lagging behind. After down-regulate ND1 and ND3 gene detected ATP decreased, ROS reduced, and the activity of COX Ⅰ is also reduced accordingly.The study shows that in human colorectal cancer cell lines HT29 and HCT116 down-regulate mitochondrial gene ND1, ND3 may through influence the output of ATP the content of ROS and the activity of COX Ⅰ and PGC1a COXⅣ gene expression way to inhibit cancer cell proliferation.Its good for further understanding of the pathogenesis and treatment of colorectal cancer provides research foundation.