The Function Of Smad1 And P53 In The Development Of Colorectal Cancer

p53 is an important tumor suppressor gene,which plays crucial role in regulating cell cycle and maintaining genome integrity.One of the most frequently mutated gene in tumor is p53.BMP-Smad signal pathway not only regulates cell proliferation,differentiation,migration and apoptotis,but also plays important role in controlling embryo development and maintaining tissue homeostasis.Smad1,one of the transcriptors in BMP-Smad signal network,shows tumor suppressive effect in tumorigenesis and tumor development through interacting with p53.After the detection of p53 and Smad1 in colorectal cancer,the experiment showed that p53 was down-regulated in most of the tumor tissues while the expression level of Smad1 was often upregulated.Through the immunohistochemical analysis of 595 colorectal tissue samples,we also found that Smad1 was mostly up-regulated in tumor compared with normal tissues.When transfected primary rectal tumor cells with pMSCV-p53 to overexpress p53 in tumor cells,the expression level of Smad1 was decreased.After the extraction of total RNA in colorectal tissues,we sequenced p53 and Smad1 respectively and found that besides some SNP variations,p53 varied in some non-SNP sites with high frequencies in tumor;the variations of Smad1 mainly existed in the linker region of the molecule,furthermore,the sequence of Smad1 in normal tissues was more diversified than in tumor tissues and there were some regular variation in normal tissues.Our study analysed the function of p53 and Smad1 in tumorigenesis and development of colorectal cancer through investigating the variation of p53 and Smad1.The results provide related evidence and support to the research of signal network in colorectal cancer,are significant to the study of colorectal cancer.