Enzymes of the AKR1B and AKR1C Subfamilies and Uterine Diseases

Endometrial and cervical cancers, uterine myoma, and endometriosis are very common uterine diseases. Worldwide, more than 800,000 women are affected annually by gynecological cancers, as a result of which, more than 360,000 die. During their reproductive age, about 70% of women develop uterine myomas and 10–15% suffer from endometriosis. Uterine diseases are associated with aberrant inflammatory responses and concomitant increased production of prostaglandins (PG). They are also related to decreased differentiation, due to low levels of protective progesterone and retinoic acid, and to enhanced proliferation, due to high local concentrations of estrogens. The pathogenesis of these diseases can thus be attributed to disturbed PG, estrogen, and retinoid metabolism and actions. Five human members of the aldo-keto reductase 1B (AKR1B) and 1C (AKR1C) superfamilies, i.e., AKR1B1, AKR1B10, AKR1C1, AKR1C2, and AKR1C3, have roles in these processes and can thus be implicated in uterine diseases. AKR1B1 and AKR1C3 catalyze the formation of PGF2α, which stimulates cell proliferation. AKR1C3 converts PGD2 to 9α,11β-PGF2, and thus counteracts the formation of 15-deoxy-PGJ2, which can activate pro-apoptotic peroxisome-proliferator-activated receptor γ. AKR1B10 catalyzes the reduction of retinal to retinol, and thus lessens the formation of retinoic acid, with potential pro-differentiating actions. The AKR1C1–AKR1C3 enzymes also act as 17-keto- and 20-ketosteroid reductases to varying extents, and are implicated in increased estradiol and decreased progesterone levels. This review comprises an introduction to uterine diseases and AKR1B and AKR1C enzymes, followed by an overview of the current literature on the AKR1B and AKR1C expression in the uterus and in uterine diseases. The potential implications of the AKR1B and AKR1C enzymes in the pathophysiologies are then discussed, followed by conclusions and future perspectives

Dimerization and enzymatic activity of fungal 17β-hydroxysteroid dehydrogenase from the short-chain dehydrogenase/reductase superfamily

BACKGROUND: 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl) is a member of the short-chain dehydrogenase/reductase (SDR) superfamily. SDR proteins usually function as dimers or tetramers and 17β-HSDcl is also a homodimer under native conditions. RESULTS: We have investigated here which secondary structure elements are involved in the dimerization of 17β-HSDcl and examined the importance of dimerization for the enzyme activity. Sequence similarity with trihydroxynaphthalene reductase from Magnaporthe grisea indicated that Arg129 and His111 from the αE-helices interact with the Asp121, Glu117 and Asp187 residues from the αE and αF-helices of the neighbouring subunit. The Arg129Asp and His111Leu mutations both rendered 17β-HSDcl monomeric, while the mutant 17β-HSDcl-His111Ala was dimeric. Circular dichroism spectroscopy analysis confirmed the conservation of the secondary structure in both monomers. The three mutant proteins all bound coenzyme, as shown by fluorescence quenching in the presence of NADP(+), but both monomers showed no enzymatic activity. CONCLUSION: We have shown by site-directed mutagenesis and structure/function analysis that 17β-HSDcl dimerization involves the αE and αF helices of both subunits. Neighbouring subunits are connected through hydrophobic interactions, H-bonds and salt bridges involving amino acid residues His111 and Arg129. Since the substitutions of these two amino acid residues lead to inactive monomers with conserved secondary structure, we suggest dimerization is a prerequisite for catalysis. A detailed understanding of this dimerization could lead to the development of compounds that will specifically prevent dimerization, thereby serving as a new type of inhibitor

Aldo-Keto Reductases and Cancer Drug Resistance

Human aldo-keto reductases (AKRs) catalyze the NADPH-dependent reduction of carbonyl groups to alcohols for conjugation reactions to proceed. They are implicated in resistance to cancer chemotherapeutic agents either because they are directly involved in their metabolism or help eradicate the cellular stress created by these agents (e.g., reactive oxygen species and lipid peroxides). Furthermore, this cellular stress activates the Nuclear factor-erythroid 2 p45-related factor 2 (NRF2)-Kelch-like ECH-associated protein 1 pathway. As many human AKR genes are upregulated by the NRF2 transcription factor, this leads to a feed-forward mechanism to enhance drug resistance. Resistance to major classes of chemotherapeutic agents (anthracyclines, mitomycin, cis-platin, antitubulin agents, vinca alkaloids, and cyclophosphamide) occurs by this mechanism. Human AKRs also catalyze the synthesis of androgens and estrogens and the elimination of progestogens and are involved in hormonal-dependent malignancies. They are upregulated by antihormonal therapy providing a second mechanism for cancer drug resistance and/or syndergize the effects of existing drugs. SIGNIFICANCE STATEMENT: Aldo-keot reductases (AKRs) are overexpressed in a large number of human tumors and mediate resistance to cancer chemotherapeutics and antihormonal therapies. Existing drugs and new agents in development may surmount this resistance by acting as specific AKR isoforms or AKR pan-inhibitors to improve clinical outcome

Possible role of estrogen metabolism and aldo-keto reductase activity in chemoresistance of ovarian cancer

High-grade serous ovarian cancer (HGSOC) is the most aggressive and chemoresistant form of epithelial ovarian cancer (OC) and is responsible for ~80% of OC-related deaths. OC is associated with disturbed estrogen action. In postmenopausal patients, estrogens are formed locally from steroid precursors. Enzymes of the AKR1C subfamily are associated with resistance to chemotherapeutic agents and are involved in the biosynthesis and metabolism of steroid hormones, thus may contribute to the growth of hormone-dependent tumors. To date, the interplay of estrogen synthesis and aldo-keto reductase activity in HGSOC chemoresistance remains unclear. The aim of this study was to investigate the differences in targeted transcriptomics of HGSOC cell lines with different sensitivity to carboplatin: OVSAHO, OVCAR-3, Kuramochi, OVCAR-4, Caov- 3, and COV362, and to evaluate the differences in correlation patterns between targeted gene expression profiles in platinum-sensitive and -resistant patients using publicly available data (PAD) (cBioPortal). We first determined the expression of genes involved in estrogen biosynthesis/metabolism (STS, SULT1E1, HSD17B1, HSD17B2, HSD17B14, PAPSS1, PAPSS2), steroid transport (SLCO1A2, SLCO1B3, SLCO2B1, SLCO4A1, SLCO4C1, ABCC1, ABCC4, ABCC11, ABCG2, SLC51A, SLC51B), estrogen action (ESR1, ESR2, GPER) and oxidative metabolism (CYP1A1, CYP1A2, CYP1B1, SULT1A1, SULT2B1, SULT1E1, UGTB7, COMT, NOQ1, NOQ2, GSTP1), NFE2L2 and AKR1C1-3 by qPCR. Next, by using PAD we conducted a correlation analysis using the Pearson correlation coefficient for gene expression data of targeted genes in OC patients. The patients were classified into two groups based on their response to platinum treatment: sensitive and resistant. The correlation matrix was computed independently for each group. Expression analysis revealed that the estrogen receptor ESR2, the efflux transporter ABCG2 and aldo-keto reductase AKR1C1 were highly expressed in the most resistant cell lines COV362 and Caov-3. The mRNA levels of estrogen biosynthesis and oxidative metabolism genes STS, HSD17B14, NOQ1, and GSTP1 increased with carboplatin resistance in the HGSOC cell lines. These results indicate the potential of ESR2, STS, HSD17B14, NOQ1, GSTP1, and ABCG2 as predictive markers for HGSOC chemoresistance. Furthermore, analysis of PAD revealed different correlation profiles between genes in sensitive and resistant patients. In chemoresistant were found a moderately to strong positive correlations (p<0.001) between gene pairs including AKR1C1– AKR1C3, AKR1C1 – NFE2L2, AKR1C1 – SULT1E1, NOQ1 – HSD17B14, COMT – SULT1A1, ABCG2 – SLC515. In chemosensitive patients was found a strong positive correlation (p<0.001) between gene pair CYP1B1 – SULT1E1. The correlation differences between sensitive and resistant OC patients suggest possible gene regulatory networks or molecular interactions contributing to the heterogeneity of response to platinum in OC. Further studies are ongoing to elucidate the mechanism of the interplay between local estrogen metabolism and aldo-keto reductase activity in HGSOC chemoresistanceBook of abstract: 4th Belgrade Bioinformatics Conference, June 19-23, 202

Synthesis and evaluation of AKR1C inhibitory properties of A-ring halogenated oestrone derivatives

Enzymes AKR1C regulate the action of oestrogens, androgens, and progesterone at the pre-receptor level and are also associated with chemo-resistance. The activities of these oestrone halides were investigated on recombinant AKR1C enzymes. The oestrone halides with halogen atoms at both C-2 and C-4 positions (13β-, 13α-methyl-17-keto halogen derivatives) were the most potent inhibitors of AKR1C1. The lowest IC(50) values were for the 13α-epimers 2_2I,4Br and 2_2I,4Cl (IC(50), 0.7 μM, 0.8 μM, respectively), both of which selectively inhibited the AKR1C1 isoform. The 13α-methyl-17-keto halogen derivatives 2_2Br and 2_4Cl were the most potent inhibitors of AKR1C2 (IC(50), 1.5 μM, 1.8 μM, respectively), with high selectivity for the AKR1C2 isoform. Compound 1_2Cl,4Cl showed the best AKR1C3 inhibition, and it also inhibited AKR1C1 (Ki: AKR1C1, 0.69 μM; AKR1C3, 1.43 μM). These data show that halogenated derivatives of oestrone represent a new class of potent and selective AKR1C inhibitors as lead compounds for further optimisations

Endometrial cancer diagnostic and prognostic algorithms based on proteomics, metabolomics, and clinical data: a systematic review

Endometrial cancer is the most common gynaecological malignancy in developed countries. Over 382,000 new cases were diagnosed worldwide in 2018, and its incidence and mortality are constantly rising due to longer life expectancy and life style factors including obesity. Two major improvements are needed in the management of patients with endometrial cancer, i.e., the development of non/minimally invasive tools for diagnostics and prognostics, which are currently missing. Diagnostic tools are needed to manage the increasing number of women at risk of developing the disease. Prognostic tools are necessary to stratify patients according to their risk of recurrence pre-preoperatively, to advise and plan the most appropriate treatment and avoid over/under-treatment. Biomarkers derived from proteomics and metabolomics, especially when derived from non/minimally-invasively collected body fluids, can serve to develop such prognostic and diagnostic tools, and the purpose of the present review is to explore the current research in this topic. We first provide a brief description of the technologies, the computational pipelines for data analyses and then we provide a systematic review of all published studies using proteomics and/or metabolomics for diagnostic and prognostic biomarker discovery in endometrial cancer. Finally, conclusions and recommendations for future studies are also given

Integration of androgen hormones in endometrial cancer biology

Endometrial cancer (EC) is a gynecological pathology that affects the uterine inner lining. In recent years, genomic studies revealed continually evolving mutational landscapes of endometrial tumors that hold great potential for tailoring therapeutic strategies. This review aims to broaden our knowledge of EC biology by focusing on the role of androgen hormones. First, we discuss epidemiological evidence implicating androgens with EC pathogenesis and cover their biosynthesis and metabolism to bioactive 11-oxyandrogens. Next, we explore the endometrial tumor tissue and the altered microbiota as alternative sources of androgens and their 11-oxymetabolites in EC patients. Finally, we discuss the biological significance of androgens\u27 genomic and nongenomic signaling as part of a medley of pathways ultimately deciding the fate of cells

Estrogens and the Schrödinger\u27s cat in the ovarian tumor microenvironment

Ovarian cancer is a heterogeneous disease affecting the aging ovary, in concert with a complex network of cells and signals, together representing the ovarian tumor microenvironment. As in the “Schrödinger’s cat” thought experiment, the context-dependent constituents of the—by the time of diagnosis—well-established tumor microenvironment may display a tumor-protective and -destructive role. Systemic and locally synthesized estrogens contribute to the formation of a pro-tumoral microenvironment that enables the sustained tumor growth, invasion and metastasis. Here we focus on the estrogen biosynthetic and metabolic pathways in ovarian cancer and elaborate their actions on phenotypically plastic, estrogen-responsive, aging immune cells of the tumor microenvironment, altogether highlighting the multicomponent-connectedness and complexity of cancer, and contributing to a broader understanding of the ovarian cancer biology