Conversely, IL1 markedly increased STS expression – hence potential – for production of E1 in SKOV3 cell line. EST can sulfoconjugate E1 to further minimize estrogen action. Intracellular steroid activation through the STS pathway is involved in estrogen-dependent epithelial cancers, such as breast and endometrial carcinomas [10], and single nucleotide polymorphisms in SULT1E1 lead to increased risk of breast [11] and endometrial [12] cancers, together with reduced survival. A study of Jewish women predisposed to breast and ovarian cancer found a link to a missense mutation (His224Gln) in the SULT1E1 gene [13]. Together, these observations suggest that if these mutations affected enzyme activity, they might be candidates for cancer promotion. Furthermore, the already substantial levels of E1S that circulate in postmenopausal women are increased by hormone replacement therapy (HRT) [14]. We therefore hypothesize that E2, is produced locally from circulating E1S the STS pathway in EOC cells. Additionally, since inflammatory cytokines such as IL1 secreted by OSE [15] are implicated in oncogenesis [16], they could have a role in activating estrogen formation within ovarian tumors. Here we demonstrate that 3-Hydroxyisovaleric acid EOC and normal OSE cells do indeed have distinct estrogen metabolizing signatures compatible with increased local generation of estrogen in ovarian cancer. 2.?Materials and methods 2.1. Ovarian tissues Non-pathalogical ovarian tissue was donated by pre-menopausal patients undergoing surgery for benign gynecological conditions IDH2 (see Supplementary Tables 1 and 2 for clinicopathological information). None of the patients had evidence of endometriosis, nor did the OSE show any evidence of endometriotic lesions. Samples of ovarian cancer tissue were donated by 12 patients with confirmed ovarian cancer (see Supplementary Table 3 for clinicopathalogical details of ovarian cancer patients). Paraffin-embedded (non-pathalogical pre-menopausal, post-menopausal and cancerous) tissue from other patients was kindly arranged by Dr. Alistair A. Williams (Department of Pathology, University of Edinburgh). Formal 3-Hydroxyisovaleric acid written consent was obtained from all patients and the project approved by the Local Research Ethics Committee (COREG reference 04/S1103/36). Previously-characterized ER positive cell lines were SKOV3 (European Collection of Cell Cultures, Public Health England, Salisbury, UK) and PEO1 [17]. 2.2. Cell collection and culture OSE cells were collected by gently brushing the ovarian surface with a Tao brush (Cook Ireland Ltd., Limerick, Ireland) and rinsing OSE cells into T75 flasks (Corning Inc., Corning, NY) with culture medium (see below) as previously described [18,19]. Primary EOC cells were retrieved from ovarian cancer tissues by enzymatic dispersion [20]. In brief, tissue was minced with scalpel blades and incubated overnight at 3-Hydroxyisovaleric acid 4?C in 0.25% trypsin (Gibco, Life Technologies, Paisley, Scotland), 0.004% DNAse1 (Sigma, Poole, Dorset, UK). Trypsin was inactivated with addition of serum-containing medium (see below) and the cells pelleted by centrifugation (500??hydrolysis of circulating 3-Hydroxyisovaleric acid E1S. This complements evidence for estrogen generation from sulfated forms in breast cancer tissue, where sulfatase pathway is 50C200 times more active than aromatase [29]. The additional presence of 17BHSD5 mRNA and protein in both OSE and EOC cells further indicates the possibility of E2 production from E1. The persistence of expression of STS, EST and 17BHSD2/5 in post-menopausal ovarian OSE indicates that enzymatic potential remains, even after cessation of follicular activity in the ovary. Conversely, the presence of EST and 17BHSD2 in OSE and EOC lends potential to the deactivation free estrogen through reverse metabolism of E2 to E1 and sulfoconjugation into E1S. Thus among other things, the estrogen-generating potential would seem to depend on the balance of STS/17BHSD5 EST/17BHSD2. We find STS mRNA expression to be similar in OSE and EOC cells whereas EST mRNA expression is substantially increased in OSE. Furthermore, 17BHSD2 mRNA levels are substantially lower in OSE compared with EOC while differences in 17BHSD5 mRNA levels are much less. These results are also in broad 3-Hydroxyisovaleric acid agreement with a recent microarray study on 12 samples of ovarian cancer epithelial cells and 12 samples of normal OSE [30], in which STS and 17BHSD1 (an alternative 17-oxoreductase to 17BHSD5) were higher, but 17BHSD2 was lower, in EOC compared with OSE. The mRNA expression profiles in both studies imply a bias toward active estrogen formation in EOC.