The Role Of SETDB1 In The Proliferation And Apoptosis Of Colorecta

Background and PurposeColorectal cancer is one of the most common gastrointestinal tumors in the world.In our country,the incidence of colorectal cancer is ranked first in digestive tract tumors.Meanwhile,with the change of dietary structure in recent years,the incidence of colorectal cancer remains In the rising,and most patients found to have been in the late,so colorectal cancer has become a serious harm to the health of Chinese people.At present,the treatment of colorectal cancer is still surgery,accompanied by radiotherapy and chemotherapy.However,the survival rate has not been significantly improved.Therefore,the study of the molecular mechanism of the occurrence and development of colorectal cancer,to find a more effective detection index for diagnosis of colorectal cancer,and accurately determine the metastasis and recurrence,to improve the diagnosis and treatment of patients with colorectal cancer,which has a very important significance for long-term survival and a higher quality of life.This gene encodes a histone methyltransferase which regulates histone methylation,gene silencing,and transcriptional repression.This gene has been identified as a target for treatment in Huntington Disease,given that gene silencing and transcription dysfunction likely play a role in the disease pathogenesis.Whether SETDB1 is involved in the progression of colorectal cancer also plays an important role,it is unclear In this study,we first detected SETDB1 protein expression in colorectal cancer tissue and investigated the relationships between SETDB1 expressions and clinicopathological parameters.The expression of SETDB1 gene was silenced by siRNA interference technique to observe the effect of low expression on the proliferation and apoptosis of colorectal cancer cells.Methods1.The expression of SETDB1 in human colorectal cancer and the relationship between SETDB1 expression and clinic pathological parameters.The expression of SETDB1 in 70 colorectal cancer tissues and normal colorectal mucosa was examined by immunohistochemistry(IHC)method.The relationship of SETDB1 expression and clinical pathological factors was analyzed.2.Target to SETDB1 expression effect on proliferation and apoptosis of colorectal cancer cellsby small interfering RNAi.1)The expression of SETDB1 in three colorectal cancer cell lines Lovo,HT29 and SW480 was detected by Real-Time PCR,and the cells with the highest expression of SETDB1 mRNA were screened for RNA interference.2)Transfection with the highest expression of SETDB1 gene by Si RNA interference technique.The efficiency of the interference detected byReal-Time PCR and Western blot.3)The biological faction of SETDB1 in cell proliferation,cell apoptosis was investigated by CCK8,flow cytometry,The expression of cyclin D1?Bcl-2and Bax was detected by Western blot and Real-Time PCR.Res?lts1.The expression of SETDB1 in CRC tissue and the relationship between SETDB1 expression parameters and clinicopathological.The results from IHC showed the expression of SETDB1 in colorectal cancer tissues was higher than that in normal colorectal mucosa,There were no significant differences of SETDB1 expression in the age,sex,tumor size,depth of invasion,lymph node metastasis and distant metastasis(P>0.05),and had significant correlation with the degree of differentiation(P<0.05).2.Effects of silencing SETDB1 gene expression by SiRNA on proliferation and apoptosis of colorectal cancer cells.1)The SETDB1 gene was highly expressed in Lovo cell lines.2)Real-Time PCR and Western blot result of expression of SETDB1 was significantly down regulated after transfecting SETDB1/Si RNA-1/-2 into Lovo cells compared to NC group.3)The results from CCK8 assay revealed that,the growth of CRC cells with SETDB1 silenced cells increased dramatically.4)The cell cycle results indicated that SETDB1 silence accelerated the G1 to G2 or S-phase transition in CRC cell lines and the cell apoptosis res?ltsindicated that SETDB1 silence the apoptosis rate was significantly increased than the control group.Western blot and Real-Time PCR res?lt of the expression of Bcl-2 was decreased and the expression of Bax and cyclinD1 were increased.ConclusionSETDB1 significantly higher expression in colorectal cancer.Invitro experiments showed that silencing SETDB1 could significantly inhibit the proliferation and promote apoptosis of colorectal cancer.