Endometrial cancer is associated with enhanced cell proliferation due to high concentrations of estrogens, and decreased cell differentiation due to low levels of progesterone and retinoic acid. It is also associated with aberrant inflammatory responses and concomitant increased production of prostaglandins.The human members of the aldo-keto reductase 1B (AKR1B) subfamily, AKR1B1 and AKR1B10, have roles in these processes and can thus be implicated in endometrial cancer. To date, there have been no reports on the expression of AKR1B1 in endometrial cancer, while AKR1B10 has only been studied at the cellular level. To evaluate the roles of these AKR1B enzymes, we investigated expression of AKR1B1 and AKR1B10 in 47 paired samples of cancerous and adjacent control endometrium at the mRNA and protein levels, by quantitative PCR, Western blotting and immunohistochemistry staining. There were significantly lower mRNA and protein levels of AKR1B1 in cancerous tissues compared to adjacent endometrium. The gene expression of AKR1B10 at the mRNA level was significantly increased, while there were significantly decreased protein levels. Immunohistochemistry revealed that both of these enzymes were present in all of the samples, and are located in epithelial cells of cancerous and control endometrial glands. Elevated levels in adjacent non-cancerous tissues imply that these enzymes are more important in the initiation of endometrial cancer than in its progression. To the best of our knowledge, this is the first report on the expression of AKR1B1 and AKR1B10 in endometrial cancer. Further studies are needed to define the precise roles of these enzymes in the pathogenesis of endometrial cancer.
COBISS.SI-ID: 30290905
Current non-invasive diagnostic methods for endometriosis lack sensitivity and specificity. In search for new diagnostic biomarkers for ovarian endometriosis, we used a hypothesis-generating targeted metabolomics approach. In a case-control study, we collected plasma of study participants and analysed their metabolic profiles. We selected a group of 40 patients with ovarian endometriosis who underwent laparoscopic surgery and a control group of 52 healthy women who underwent sterilization at the University Clinical Centre Ljubljana, Slovenia. Over 140 targeted analytes included glycerophospholipids, sphingolipids and acylcarnitines. The analytes were quantified by electrospray ionization tandem mass spectrometry. For assessing the strength of association between the metabolite or metabolite ratios and the disease, we used crude and adjusted odds ratios. A stepwise logistic regression procedure was used for selecting the best combination of biomarkers. Eight lipid metabolites were identified as endometriosis-associated biomarkers due to elevated levels in patients compared with controls. A model containing hydroxysphingomyelin SMOH C16:1 andthe ratio between phosphatidylcholine PCaa C36:2 to etherphospholipid PCae C34:2, adjusted for the effect of age and the BMI, resulted in a sensitivity of 90.0%, a specificity of 84.3% and a ratio of the positive likelihood ratio to the negative likelihood ratio of 48.3. Our results suggest that endometriosis is associated with elevated levels of sphingomyelins and phosphatidylcholines, which might contribute to the suppression of apoptosis and affect lipid-associated signalling pathways. Our findings suggest novel potential routes for therapy by specifically blocking highly up-regulated isoforms of phosphpolipase A2 and lysophosphatidylcholine acyltransferase.
COBISS.SI-ID: 30025945
Oxidative metabolism of estrogens was studied in 31 ovarian endometriosis and 29 normal endometrium samples, by qPCR. Expression was monitored for genes encoding five estrogen hydroxylating, five hydroxy (OH)-estrogen conjugating, and three estrogen quinone detoxifying enzymes. CYP1B1, COMT, NQO1, and GSTP1 protein levels were determined using Western blotting and immunohistochemistry staining. Increased expression of CYP1A1, CYP3A7 and COMT, and higher levels of MB-COMT were seen in endometriosis, as compared to normal endometrium. Expression of CYP1B1, CYP3A5, SULT1A1 and NQO2 was unchanged, with comparable CYP1B1 protein levels. Expression of SULT1E1, SULT2B1, UGT2B7, NQO1, and GSTP1 was decreased. Three NQO1 isoforms were detected; NQO1c appears to be endometriosis-specific. Our data indicate a disturbed balance between phase I and II metabolizing enzymes in endometriosis, potentially leading to excessive OH-estrogen and altered ROS formation, and stimulation of proliferation of ectopic endometrium. This is the first report on disturbed expression of estrogen oxidative metabolism genes in ovarian endometriosis
COBISS.SI-ID: 30367193