Cancer Res 2006, 66:9617–9624.PubMedCrossRef 34. Winter MC, Holen I, Coleman RE: Exploring the anti-tumour

activity of bisphosphonates in early breast cancer. Cancer Treat Rev 2008, 34:453–475.PubMedCrossRef Competing interests The authors declare that they have no competing interests. Authors’ contributions BK carried out cytotoxicity experiments, and participated in PLX4032 purchase the drafted manuscript, BK participated in the design of the study, UV performed statistical analysis, UM carried out molecular genetic studies, BC carried out cytotoxicity experiments, HA carried out apoptosis experiments, AK carried out apoptosis experiments, and molecular genetic studies, SU participated in design of the study, RU conceived of the study, and participated in its design and coordination. All authors read and approved the final manuscript.”
“Background Estrogen stimulation plays an important role in human breast cancer cell growth and development. It was reported HDAC inhibitor that estrogen could affect breast cancer risk through stimulating cellular

proliferation and promoting tumor progression[1]. It might be important to obtain a better understanding of enzymatic mechanism in breast cancer tissues. Enzymatic mechanism involves in the formation of estrogen including two main pathways. One is the sulfatase pathway which involves conversion of inactive estrone sulfate into active estrone[2]. Sulfotransferase (SULT) sulfonates estrone to inactive estrone sulfate (E1-S), whereas steroid sulfatase (STS) hydrolyzes estrone sulfate to estrone. Another is the aromatase pathway which converts androstenedione into estrone and aromatase inhibitor has been successfully used in breast cancer standard treatment[3]. However, it was reported that aromatase manner was five hundred times lower than sulfatase one pointed by quantitative enzymatic evaluation [4]. Besides, early study showed that the conversion of estrogen to the inactive estrogen sulfate was very essential, as serum level of unconjugated estrone

(E1) or estradiol (E2) had 10-fold lower than the level of E1-S. In addition, tissue concentration of E2 in breast cancer was 10 times higher than the level in plasma. The accumulation of E2 in breast cancer was mainly caused by the over expressed STS and the decreasing of SULT Tideglusib expression [5]. There are three families of SULTs. They are SULT1 family which is the major “”phenol”" SULT, sulfating a wide range of substrates including eight subfamilies, SULT2 family and SULT4 family. SULT1A1 gene locates in chromosome 16p11.2 – p12.1. Previous study reported that exon 7 of the SULT1A1 gene contained a G to A transition at codon 213 and showed that relevant polymorphism significantly reduced its enzymatic activity [6]. For the above reasons, genetic studies of SULT polymorphisms may improve our understanding of the mechanism of SULT and enable us to screen for individuals at high risk for different cancers.