Research About Effections Of Down-regulation Twist Gene Expression On Vito Proliferation And Invasion Of Cell HCT116

Object: Colorectal cancer is the common digestal malignant tumor in our country, the morbidity and mortality rate all present obvious up-trend.The colorectal cancer occurance is an muti-factor and muti-step progress, forms the different pathology stage in the corresponding phenotype. After being subjected to various outside factor changed include living creature, physics, and chemistry.and so on, a series of molecule horizontal was occurred in normal cells which finally cause table type's changing and become tumor. The occurrence of the tumor is also the result of out balance between the cell proliferation and apoptosis.Colorectal cancer's occurance had a close relation with cell apoptosis.It is reported that Twist regulates expression of lots of genes in transcriptional level,its original function was found to regulate the development of Embryo by EMT. It is recently confirmed that twist was engaged in epithelial mesenchy-mal transi-tion(EMT)in some epitheliumoriginal tumors and promote its invasion and metastasis.Meanwhile, twist can induce a set of mesochymal markers in the progress of tumors separately. It was shown that twist was over-expressed in various kinds of solid tumors, like breast cancers, prostate cancers, melanoma and osteosarcoma; it can promote apoptosis of human breast cancers and melanoma. The expression of twist was also confirmed in human breast cancer MCF-7 cell line, colon cancer HCT116 cell line, kidney cancer 786-0 cell line, gastric cancer MNK cell line, hepatic cancer HepG2 cell line and normal hepatic LO2 cell line, its expression was highest in colon cancer HCT116 cell line, while the lowest in normal hepatic LO2 cell line.In our former research ,in the three colon cancer cell lines,the expression was highest in colon cancer HCT116 .In our fomer research we find that if we up regulate the expression of Twist gene the proliferation and invasion of SW480 cell lines were promoted.Methods: In this experiment, we used SiRNA to down regulate the Twist gene expression and G418 sieve the cells.we used RT-PCR and Western blot to examine the result. We use MTT method to draw the Cell growth curve, wound healing assay method to observe the cell migrantion ,transwell invasion method to observe cell invasiveness in vito.Results:1 RT-PCR and Western blot results: Twist mRNA and protein is lower in the invasived cells than in control group cells.2 MTT method result show :compared with control group, the growth rate of stably transfectec group was significantly lower than control group(P<0.05).3 Wound Healing assay results:The transfected and group cells migrated slowly and closed the wound by (15.06±2.56)% after 24h and (25.77±4.06)% after 48h. In contrast ,control group cells only closed the wound by (25.24±1.65)%and (45.37±6.79)%in the same time interval.The wound closed rate in transfected group cells was significantly lower than in control groups(P<0.05).4 The number of invasive cells in transfected groups were(68±18)and were(123±20) in control group.The invasive cells number in transfected groups was significantly lower than in control group(P<0.05).Conculsions:1 In this research Twist gene was interferenced successfully in the HCT116 cells and can be stably experssed.2 After down-regulated the Twist gene it can be down the vito proliferation of the HCT116 cell .It is show that Twist gene can effect the vito proliferation of the HCT116 cells.3 After down-regulated the Twist gene it can be down the vito migration of the HCT116 cell .It is show that Twist gene can improve the migration of the HCT116 cells.4 After down -regulated the Twist gene it can be improve the vito invasion of the HCT116 cell .It is show that Twist gene can effect the vito invasion of the HCT116 cells.