Screening Of Novel Regulatory Factors Of Estrogen Receptor Signaling Pathway And Its Function

Breast cancer was common malignant tumor and it jeopardized women’s health,18% gynaeic tumors were breast cancer.Up to now,some results of pathogenetic research had been gained.As we know,ER(Estrogen Receptor)acted importantly in the development of breast cancer,especially connected different signal pathway.The transcriptional factor of ERα,phosphorylation sites of ERβand corresponding kinase were researched in this paper.Firstly,46 deletion mutants of ERαpromoter were constructed. And the activity of mutants were tested in three different breast cancer cell lines,which were ZR75-1、Mcf-7 and MDA-MB-231.The longest ERαpromoter mutant,as a reporter,was taken to screen transcriptional factors reclaimed earlier,and 13 valuable transcriptional factors were ascertained,such as TL03(transcriptional factor L03).The results of different transcriptional factors effected the transcription of ERαwere researched,8 of 13 transcriptional factors were tested in Mcf-7 and ZR75-1.And localization research of 5 of those 8 transcriptional factors were taken in ZR75-1 cell line,the range of localization was about 500bp.Transcriptional activity mediated by ER,was regulated by binding estrogen or its phosphorylation.It was the truth that phosphorylation of ERαwas understood better.The comparison of sequence of ERαand ERβwas taken to localize the phosphorylation sites of ERβand to ascertain the corresponding kinase.The homology of ERαand ERβwas 44.13%,and it implied that some sites of ERβ,which corresponded to the phosphorylation sites of ERα,might be the phosphorylation sites.According to this assumption,6 potential phosphorylation sites of ERβwere selected.Thus 6 point mutants of ERβwere constructed by recombination PCR to change the original amino acid to Ala,and ERβSer-75 was found,it was important for transcriptional activity mediated by ERβ.According to the 6 potential phosphorylation sites,21 kinases were selected,KD 10(Kinase D10)and KA21 were studied.Finally,phosphorylation sites were ascertained as ERβSer-200 for KD10,ERβSer -135 and ERβSer -264 for KA21.ER played its roles via complicated cross-talk signal processes.From the binding of receptor located in cell membrane with ligand to the expression of gene intranuclear,multistrata signal transduction might be taken.And many signals were transducted via phosphorylation.Since ER acted importantly in the development of breast cancer,it had much significance for transcriptional factors and kinase of ER discussed in this paper.