Expression And Preliminary Functional Studies Of TP53I11 Gene In Breast Cancer

Background and purpose:Breast cancer is the most common cancer and the leading cause of cancer death among women around the world,and the two index are increasing year after year.The metastasis and invasion plays an important role in the prognosis and morality in breast cancer.Therefore,searching for specific markers of breast cancer metastasis and exploring the molecular biological mechanisms of breast cancer can provide a certain assessment value in survival,diagnosis and treatment of breast cancer.TP53I11 also called PIG11(p53-induced gene),was firstly detected when exploring p53-mediated apoptosis in colon cancer,which can be induced by p53 expression.It was reported to be located in 11p11.2 and act as a tumor suppressor in liver cancer.It has been announced that TP53I11 is specifically expressed in epithelial-derived tissues and down regulated or lose its expression in tumor compared to normal tissues such as hepatic carcinoma,gastric cancer,colon cancer,and breast cancer,and it related to tumor proliferation and invasion.However,the role of TP53I11 in breast cancer still stay unclear.The purpose of this study is to found the correlation between TP53I11 expression and clinicopathologic features and prognosis in breast cancer patients by performing immunohischemistry in The Tissue Microarrays containing 210 breast cancer tissues.Moreover,we investigated the effect of TP53I11 on proliferation and migration ability in breast cancer cells by up-regulating and down-regulating the expression of TP53I11.Methods:1.The Tissue Microarrays containing 210 breast cancer tumor were used for detecting the expression of TP53I11 and the relationship with clinicopathologic features and prognosis in breast cancer patients.2.After we constructed and transferred plasmid PCDH-cmv-mcs-ef1-puro-flag for up-regulating TP53I11 expression in MDA-MB-231 and BT549 cell lines,IncuCyte,wound healing and Transwell tests were performed to discovered abilities of proliferation and migration in breast cancer cells.Crispr/cas9 system was used to knock down the expression of TP53I11 in MDA-MB-468 cell line to verified the function results.3.The expression of Vimentin,MMP9,proteins in NF-?B pathway were detected by Western Blot.4.SPSS 17.0 statistical software was used to perform statistical analysis.Data was represented by using(x±S),the experimental data were compared by t-test analysis,Chi-square test,survival analysis and Cox regression analysis,P<0.05 was defined the difference was statistically significant.Results:1.Immunohischemistry was performed to detecte TP53I11 expression in the tissue microarray.We found TP53I11 expression was closely related to ER(p=0.003),PR(p=0.004)statues and subtype(p=0.004).Kaplan-Meier and survival analysis revealed that patients with high expression of TP53I11 has a better DFS and OS compared to patients with low expression of TP53I11,and it can act as an independent prognosis factor in breast cancer patients.2.MDA-MB-231 and BT549 cell lines were choose for further experiments.When we constructed and transferred plasmid PCDH-cmv-mcs-ef1-puro-flag with these two cell lines,the ability of proliferation and migration of breast cancer cells were reduced.The functional results by knocking down TP53I11 expression with Crispr/cas9 system in MDA-MB-468 cells were consistent with results above.3.Vimentin,MMP9,NF-?B p65 and its target gene CXCR4 were down regulated after up regulating TP53I11 expression,and these protein were up regulated after knocking down TP53I11 expression.Conclusion:TP53I11 can act as an independent prognosis factor in breast cancer patients,and it can inhibit the ability of proliferation and migration in breast cancer cells.It may play its tumor suppressor role through Vimentin,MMP9 and NF-?B pathway.