HDAC11 Suppresses For Invasion And Metastasis Of Basal Like Breast Cancer

Background:Basal-like breast caner with low expression of hormone receptor and human epidermal growh receptor 2 has poor prognosis.For its character,our study try to find protential target treat with BLBC.HDAC11 is a class IV member of histone deacetylase family,its function in regulation of cancer cell invasion and metastasis remains unclear.Since previous study suggested that promoter methylation of HDAC11 gene is highly associated with poor outcome of ovarian cancer.Some study found HDAC11 associates with the survival of motor neuron complex and participates in mRNA splicing process Therefore,Our study try to find the function of HDAC11 with BLBC.BLBC cells have intrinsic phenotypic plasticity for epithelial mesenchymal transition(EMT)and highly express EMT inducing.transcriptional factors.Twist is a major pro-EMT transcription factor which is known to govern tumor cell invasion and metastasis.Methods:Microarray gene expression data for breast carcinoma patients from TCGA and oncomine databases.Cell migration amd invation was assessed by transwell assay.HDAC11,Twist and HAS2 expression was estimated by western blotting.We constructed deletion mutant plasmids to determine the specific binding regions.Balb/c nude mice were used with in vivo studies by injection of MDA-MB-231.Western blot results revealed the presence of HDAC11,in the immunoprecipitated Twist complex.Results:We analyzed the gene expression from 6 different databases and the protein expression from 14 differernt cell lines.We found HDAC11 is lowly expressed in BLBC(p<0.001).Over-expression of HDAC11 with BT549,SUM1315 and MDA-MB-231 were accessed by western blotting.And then our study prove that HDAC11 inhibits basal like breast cancer invasion and metastasis by transwell assay or in vivo studies by injection of MDA-MB-231 into tail vein of balb/c nude mice.To identify the underlying molecular mechanism of HDAC 11 mediated metastasis-suppressive role,we pulled down endogenous Twist,from SUM1315 and BT549 cells.Western blotting results revealed the presence of HDAC11 in the immunoprecipitated Twist complex.We constructed HA-tagged wild-type and five deletion mutant plasmids of Twist,and three deletion mutant plasmids of HDAC11.TDL4 mutant completely lost while others retained strong interaction with HDAC11.HDL2 and HDL3 completely lost interaction with Twist.Knockdown of endogenous HDAC11 of BT549 cells by small interfering RNA promoted cell invasion,which were partially ameliorated by co-knockdown of Twist.And we over-expressed Twist and simultaneously knocked down endogenous HDAC11 in T47D cells by lenti-virus expression system lead to the same consequence.Previously we performed cDNA microarray analysis of T47D/Twist cells and found the mRNA expression of Hyaluronan synthase 2(HAS2)was greatly induced.Twist over-expression in T47D cells greatly induced the hyaluronan production,while HDAC11 over-expression significantly blocked the induction.Chromatin immunoprecipitation results from SUM1315 and BT549 cells showed that Twist associated with HAS2 gene promoter,ectopic expression of HDAC11 reduced the binding of Twist to HAS2 gene promoter.The mRNA levels of HAS2 and Twist in gene expression datasets and found their expression was positively correlated to each other.Conclusion:Our data indicate that HDAC11 is lowly expressed in BLBC compared to other breast cancer subtypes.Ectopic expression of HDAC11 in BLBC cells suppresses the cell invasion in vitro as well as cell metastasis in vivo.Mechanistically,HDAC11 physically occupies the DNA binding domain of Twist protein,antagonizes its pro-invasive function and represses Twist-induced HAS2 gene transcription.Taken together,our data suggest that HDAC11 acts as a negative modulator of invasion and metastasis of BLBC cells.