The Expression Of ATF3 In Diffuse Large B-cell Lymphoma And Its Effect On Cell Proliferation And Drug Resistance

Objective To explore the relationship between Activating Transcription Factor 3(ATF3)and the clinicopathological features of patients with Diffuse Large B-cell Lymphoma(DLBCL);To explore the effect of ATF3 on DLBCL cell proliferation ability in vitro,and to investigate the change of the drug sensitivity of tumor cells with different ATF3 levels;And to explore its possible molecular mechanism in the development of the progress of DLBCL.Methods The immunohistochemical staining method was used to detect the expression levels of ATF3 and p53 protein in the tumor tissues of 119 patients with DLBCL.The TMD8 cell line of activated B-cell-like DLBCL and BJAB cell line of germinal center Bcell-like DLBCL that with stable high or low expression level of ATF3 were established.RT-PCR and Western Blot were used to detect the expression level of ATF3 and CCK8 cell proliferation test was carried out to detect the effect of different ATF3 expression levels on the proliferation of DLBCL cells in vitro.RT-PCR was used to test the expression of BCL2,P21,RELA and other proteins in DLBCL cells with different ATF3 expression levels after48 hours proliferation in vitro.The sensitivity for Doxorubicin chemotherapeutic drugs experiment was conducted to study The impact of Doxorubicin drug resistance in DLBCL cells with different ATF3 expression levels.Results Among the 119 DLBCL patients,38 cases had positive expression of ATF3(38/119,31.93%),81 cases had negative expression(81/119,68.07%),43 cases had positive expression of mutp53(43/119,36.13%),and 76 cases had negative expression(76/119,63.87%).There was significant correlation between the expression level of ATF3 protein and the level of p53 protein(P<0.05).The level of ATF3 protein expression is significantly related to the clinical stage of the patient(P<0.05),but not statistically related to gender,age,IPI score,and Hans classification(P>0.05).Survival analysis showed that those with positive ATF3 protein expression had a significantly shorter overall survival time than those with negative ATF3 protein expression(P<0.05).Cell proliferation experiments showed that the in vitro proliferation activity of the BJAB cell group was significantly higher than that of the TMD8 group.Compared with the control group,the proliferation activity of TMD8 and BJAB cells in vitro was significantly increased when the ATF3 expression level was up-regulated while significantly reduced when the ATF3 expression level was down-regulated,and the differences in each group were statistically significant(P<0.05).After 48 hours of in vitro cells culture,RT-PCR analysis showed that the expression level of BCL2,RELA,HER2,and P21 increased in the TMD8 cell group,and the expression levels of P21,BCL2,HER2,RELA,PDCD5,CASP3,and BIRC5 increased in the BJAB cell group when the expression of ATF3 was up-regulated.The expression of HER2,CDKN2 A,CCND-1 increased in the TMD8 cell group,and the expression of CASP3 and HER2 increased in the TMD8 cell group when the expression of ATF3 was downregulated.The number of tumor cells in the group which the expression of ATF3 in TMD8 and BJAB cells was down-regulated was reduced compared with the control group after Doxorubicin was added,and the number of survival tumor cell in the two groups which the expression of ATF3 in TMD8 and BJAB cells was up-regulated was increased after Doxorubicin was added.The cell survival in the TMD8 group was better than that in the BJAB group.Conclusion The expression level of ATF3 is positively correlated with the expression of p53 protein in DLBCL.The expression level of ATF3 can be used as a prognostic indicator for patients with DLBCL.Up-regulating the expression level of ATF3 can promote the proliferation activity of DLBCL cells and increase the resistance of cells to Doxorubicin.ATF3 may regulate proliferation and drug resistance of DLBCL tumor cell in vitro by regulating level of BCL2,RELA and HER2,et al.