Mouse Mrad9 And Mrad1 Gene Knockout Enhances Susceptibility Of Tumor And Studies On Its Protein Functional Differences

The genetic materials of organisms are facing endogenous and exogenous factors that cause a variety of damages at every moment.If not promptly repair these damages,it would lead to the accumulation of errors in the genetic materials and eventually causing organisms disastrous consequences,for example,cancer.The good news is that over a long period of biological evolution,it has developed a nearly perfect DNA damage repair mechanisms to clear the accumulation of error genetic materials.Rad9,Rad1 and Husl is a group of highly conserved genes from yeast to human eukaryotic organisms.It's protein products can form 9-1-1 heterotrimeric complex and plays an important role in controlling cell cycle surveillance,DNA damage repair and apoptosis.The current study suggests that,Rad9 and Rad1 protein not only can form 9-1-1 heterotrimeric complex but also plays a role as tumor suppressor in monomeric form.Rad9 and Rad1 protein plays an important role in tumor suppressing besides form 9-1-1 heterotrimeric complexTherefore,in order to answer the question if Rad9 and Rad1 can function besides the 9-1-1 complex from the biological individual level,we take the same genetic background mouse Mrad9^+/-and Mrad1+-/as experimental subjects,using DMBA+TPA to induce tumor occur.The experiments show that mice Mrad9^+/-and Mrad1^+/-have different tumor incidence,so Rad9 and Rad1 proteins do not strictly play the role in the form of 9-1-1 complex.Meanwhile,tumor incidence of Mradl^+/-mice is higher than the Mrad9^+/-mice,which indicates Radi protein plays a more important role than Rad9 in suppressing tumors.In order to clarify the differences of the tumor suppression function between protein Rad1 and Rad9,we separate Keratinocytes from Mrad9^+/-and Mradl^+/-keratinocytes neonatal mice and conduct growth curve experiments.The results show Mrad9 removed significantly and obstruct the keratinocytes growth,indicating that Rad9 and Rad1 play different roles in cell cycle regulation and apoptosis.Further experiments are underway,by using flow cytometry to analyze the following differences between Mrad9^+/-and Mradl^+/-,Keratinocyte cell cycle differences,Differences in DNA double-strand breaks,Keratinocyte apoptosis differences and pathway activating differences.The above experimental researches are focused on studying the functional differences between Rad9,Rad1.