In endometriosis lesions, the balance is tilted in favor of enzymes producing E(2). This is due to a suppression of types 2 and 4 17beta-HSD, and an increased expression of aromatase and type 1 17beta-HSD in ectopic endometrium.

Until recently, relaxin (RLX) has been known predominantly for its effects on the reproductive system, where it induces remodelling of the extracellular matrix and up-regulation of matrix metalloproteases (MMPs). In solid cancers, tissue remodelling and MMP activation are essential for invasion and metastasis. We therefore investigated the effect of RLX on invasiveness and MMP expression of human breast cancer cell lines. Upon incubation with porcine RLX, the invasiveness of SK-BR3 cells was significantly increased. Similar effects could be achieved in MCF-7 cells, especially when RLX was combined with epidermal growth factor. Enhanced invasiveness was accompanied by up-regulation of MMP production and could be almost completely blocked by the MMP inhibitor FN 439. Zymography revealed increased secretion of MMP-2, -7 and -9, associated with up-regulated mRNA concentrations of MMP-2, -9, -13 and -14. mRNA expression levels of MMP-1, -3, -7, -8, -10, -11, -12 and of tissue inhibitors of metalloproteases-1, -2, -3 and -4 were either very low or not detectably influenced by RLX. Taken together, RLX enhances in-vitro invasiveness of breast cancer cell lines by induction of MMP expression. It remains to be clarified whether RLX might play a similar role in vivo and promote tumour progression.

The protein encoded by the HSD17B7 gene was originally described as a prolactin receptor-associated protein and as 17beta-hydroxysteroid dehydrogenase (HSD) type 7. Its ability to synthesize 17beta-estradiol in vitro has been reported previously. However, we demonstrate that HSD17B7 is the ortholog of the yeast 3-ketosteroid reductase Erg27p and converts zymosterone to zymosterol in vitro, using reduced nicotinamide adenine dinucleotide phosphate as cofactor. Expression of human and murine HSD17B7 in an Erg27p-deficient yeast strain complements the 3-ketosteroid reductase deficiency of the cells and restores growth on sterol-deficient medium. A fusion of HSD17B7 with green fluorescent protein is located in the endoplasmic reticulum, the site of postsqualene cholesterogenesis. Further critical evidence for a role of HSD17B7 in cholesterol metabolism is provided by the observation that its murine ortholog is a member of the same highly distinct embryonic synexpression group as hydroxymethyl-glutaryl-coenzyme A reductase, the rate-limiting enzyme of sterol biogenesis, and is specifically expressed in tissues that are involved in the pathogenesis of congenital cholesterol-deficiency disorders. We conclude that HSD17B7 participates in postsqualene cholesterol biosynthesis, thus completing the molecular cloning of all genes of this central metabolic pathway. In its function as the 3-ketosteroid reductase of cholesterol biosynthesis, HSD17B7 is a novel candidate for inborn errors of cholesterol metabolism.

Endometriosis is defined as the presence of endometrial glands and stroma within extrauterine sites, and it is well known that endometriosis is an estrogen-dependent disease. The defective formation and metabolism of steroid hormones is responsible for the promotion and development of endometriosis. In the present study we examined the mRNA levels of six enzymes that are involved in the metabolism of estrogen and progesterone--aromatase, 17beta-hydroxysteroid dehydrogenase (17beta-HSD) types 1, 2 and 7, sulfatase and sulfotransferase--and of the steroid receptors--estrogen receptors alpha and beta (ERalpha, ERbeta) and progesterone receptors A and B (PRAB)--implicated in human ovarian endometriosis. We analyzed 16 samples of ovarian endometriosis and 9 of normal endometrium. The real-time polymerase chain reaction analyses revealed that six of the nine genes investigated are differentially regulated. Aromatase, 17beta-HSD types 1 and 7, sulfatase and ERbeta were statistically significantly upregulated, while ERalpha was significantly downregulated, in the endometriosis group compared with the control group. There were no significant differences in 17beta-HSD type 2, sulfotransferase and PRAB gene expression. Our results indicate that, in addition to the previously reported upregulation of aromatase, upregulation of 17beta-HSD types 1 and 7 and sulfatase can also increase the local estradiol concentration. This could thus be responsible for the estrogen-dependent growth of endometriotic tissue. Surprisingly ERalpha was downregulated.

Magnetic resonance DTI by reduction of FA identified renal pathologies of diabetic nephropathy such as glomerulosclerosis, interstitial fibrosis, and tubular damage. Representing different stages of disease, DM and DM UNX animals could be differentiated. Thus, MR DTI may be valuable for noninvasive detection and monitoring of renal pathology in patients with diabetes.