Genetic and Phenotypic Factors Affecting Glycemic Response to Metformin Therapy in Patients with Type 2 Diabetes Mellitus.

Metformin is an oral hypoglycemic agent widely used in clinical practice for treatment of patients with type 2 diabetes mellitus (T2DM). The wide interindividual variability of response to metformin therapy was shown, and recently the impact of several genetic variants was reported. To assess the independent and combined effect of the genetic polymorphism on glycemic response to metformin, we performed an association analysis of the variants in ATM, SLC22A1, SLC47A1, and SLC2A2 genes with metformin response in 299 patients with T2DM. Likewise, the distribution of allele and genotype frequencies of the studied gene variants was analyzed in an extended group of patients with T2DM (n = 464) and a population group (n = 129). According to our results, one variant, rs12208357 in the SLC22A1 gene, had a significant impact on response to metformin in T2DM patients. Carriers of TT genotype and T allele had a lower response to metformin compared to carriers of CC/CT genotypes and C allele (p-value = 0.0246, p-value = 0.0059, respectively). To identify the parameters that had the greatest importance for the prediction of the therapy response to metformin, we next built a set of machine learning models, based on the various combinations of genetic and phenotypic characteristics. The model based on a set of four parameters, including gender, rs12208357 genotype, familial T2DM background, and waist-hip ratio (WHR) showed the highest prediction accuracy for the response to metformin therapy in patients with T2DM (AUC = 0.62 in cross-validation). Further pharmacogenetic studies may aid in the discovery of the fundamental mechanisms of type 2 diabetes, the identification of new drug targets, and finally, it could advance the development of personalized treatment.

Glucose variability as the risk factor of preeclampsia in pregnant patients with type 1 diabetes mellitus.

OBJECTIVE: To analyze glucose variability and investigate its role as a predictor for preeclampsia development in pregnant women with type 1 diabetes mellitus (T1DM) with various insulin therapy regimens. METHODS: A total of 200 pregnant women with T1DM were included in the study. A hundred women used continuous subcutaneous insulin infusion (CSII), and the rest of the group was administered with multiple daily insulin injections (MDI). Continuous glucose monitoring (CGM), index calculation of glucose variability (MAGE, MODD, CONGA, and CV), assessment of preeclampsia frequency and severity were conducted. RESULTS: The work results show the link between the severity rate of preeclampsia and the duration of T1DM as well as the level of HbA1c before and during pregnancy. The rate of preeclampsia in the group of women, using CSII comprises 26.8% of cases that appear less than in the group of those, administered with MDI that is 46.6% (χ2 = 5.45; р < .05). A negative correlation is defined between pathological glucose variability and gestational age when preeclampsia occurs. A negative correlation was also revealed between MODD, CV, and the time for the detection of preeclampsia: r = -0.30, r = -0.24, respectively. The study illustrates the correlation obtained between preeclampsia and glucose variability and the value of MAGE, MODD, CV, and SD. Preeclampsia development is affected by the duration of hyperglycemic conditions in the third trimester of pregnancy. The data in the group of women using MDI marks the early development of preeclampsia on the 33.0 [32-34] week of pregnancy compared to the group of women practicing CSII on 35.5 [33-36] week of pregnancy (Z = 5.4; p < .001). The increase of risk of preeclampsia development is proved in pregnant patients with T1DM when the hyperglycemic condition lasts more than 25% of a 24-h period according to the rate of CGM and measurements of glucose variability MODD > 1.07 and CONGA > 3.39. CONCLUSION: Comprehensive evaluation of the glycemic profile while using CGM revealed a correlation between pathological glucose variability and the frequency and severity of preeclampsia thus proving the benefits of CSII in pregnant patients with T1DM to perform glycemic targets and decrease glucose variability, which eventually led to the decrease of preeclampsia frequency in this group of women.

Vitamin D significance in pathogenesis of endometriosis.

Genital endometriosis (GE) is a widespread multifactorial disease thus making it necessary to carry on studying its pathogeny in order to work out target therapy techniques. Studying vitamin D role in GE pathogeny is a new promising research trend. PATIENTS AND TECHNIQUE: 25(ОН)D level was determined in peripheral blood (PB) of 440 patients with GE and in peritoneal fluid (PF) - in 49 GE patients; the same test in PB was performed in 30 patients of the control group with the ovulatory menstrual cycle and no gynecologic pathology. 129 patients with GE, as well as 82 women of the control, underwent examination of vitamin D receptor (VDR) polymorphism gene in BsmI, FokI, and TaqI polymorphic locus. We examined vitamin D receptor expression in the eutopic and ectopic endometrium in 32 women with GE and in the endometrium of 20 women from the control group. We also compared the efficacy of combined therapy involving colecalciferol to the standard hormone modulating therapy. RESULTS: It was established that the prevalent GE forms are characterized by lower 25(ОН)D levels both in PB and in PF. It was also found that G/G genotype of VDR BsmI gene polymorphic variant 1.9 times increases GE occurrence risk. VDR expression was authentically lower in the ectopic endometrium compared to the eutopic endometrium. Patients with GE show no VDR expression cyclic variations in the endometrium which is contrary to the control. Therapy in combination with colecalciferol promotes a more expressed decrease of endometriosis-associated pain syndrome and psycho-emotional stabilization of GE patients compared to the standard hormone modulating therapy. CONCLUSION: Vitamin D deficiency plays a significant role in the pathogenesis of GE and Vit D may be applied as its targeted therapy.

The effectiveness of resveratrol in treatment of PCOS on the basis of experimental model in rats.

PURPOSE OF THE STUDY: Polycystic ovary syndrome (PCOS) is a widespread endocrine disorder in women of reproductive age. Further research is required to justify new directions of effective targeted therapy of this condition. Resveratrol possesses anti-inflammatory, antioxidant and antidiabetic properties. The purpose of this study was to evaluate the potential effectiveness of resveratrol in PCOS based on the created model of this disease in Wistar rats. MATERIALS AND METHODS: The PCOS model was created by oral administration of letrozole to female Wistar rats.. The animals received resveratrol at a dosage of 20 mg/kg and 30 mg/kg for the next 30 days. Then ovariectomy was performed for histological confirmation of the effectiveness of resveratrol in the treatment of PCOS. Regularity of estrous cycle, animal's body mass and the level of soluble receptors for advanced glycation end products (sRAGE) in the blood of rats were also evaluated in dynamics. RESULTS: The study revealed that administration of resveratrol leads to dose-dependent restoration of normal morphology of ovarian tissue, normalizes regularity of estrous cycle and decreases body weight of rats with PCOS. CONCLUSION: The results obtained in rats suggest that resveratrol may be a promising agent for the treatment of PCOS in women.

Cytogenomic Profile of Uterine Leiomyoma: In Vivo vs. In Vitro Comparison.

We performed a comparative cytogenomic analysis of cultured and uncultured uterine leiomyoma (UL) samples. The experimental approach included karyotyping, aCGH, verification of the detected chromosomal abnormalities by metaphase and interphase FISH, MED12 mutation analysis and telomere measurement by Q-FISH. An abnormal karyotype was detected in 12 out of 32 cultured UL samples. In five karyotypically abnormal ULs, MED12 mutations were found. The chromosomal abnormalities in ULs were present mostly by complex rearrangements, including chromothripsis. In both karyotypically normal and abnormal ULs, telomeres were ~40% shorter than in the corresponding myometrium, being possibly prerequisite to chromosomal rearrangements. The uncultured samples of six karyotypically abnormal ULs were checked for the detected chromosomal abnormalities through interphase FISH with individually designed DNA probe sets. All chromosomal abnormalities detected in cultured ULs were found in corresponding uncultured samples. In all tumors, clonal spectra were present by the karyotypically abnormal cell clone/clones which coexisted with karyotypically normal ones, suggesting that chromosomal abnormalities acted as drivers, rather than triggers, of the neoplastic process. In vitro propagation did not cause any changes in the spectrum of the cell clones, but altered their ratio compared to uncultured sample. The alterations were unique for every UL. Compared to its uncultured counterpart, the frequency of chromosomally abnormal cells in the cultured sample was higher in some ULs and lower in others. To summarize, ULs are characterized by both inter- and intratumor genetic heterogeneity. Regardless of its MED12 status, a tumor may be comprised of clones with and without chromosomal abnormalities. In contrast to the clonal spectrum, which is unique and constant for each UL, the clonal frequency demonstrates up or down shifts under in vitro conditions, most probably determined by the unequal ability of cells with different genetic aberrations to exist outside the body.

Prolonged cyclical and continuous regimens of dydrogesterone are effective for reducing chronic pelvic pain in women with endometriosis: results of the ORCHIDEA study.

OBJECTIVE: To compare the effectiveness of two different treatment regimens of dydrogesterone in the management of endometriosis-related chronic pelvic pain. DESIGN: Observational, prospective cohort study over six months. SETTING: Twenty gynecology clinics in the Russian Federation. PATIENT(S): Three hundred fifty women from 18 to 45 years of age with endometriosis and chronic pelvic pain with or without dysmenorrhea. INTERVENTION(S): Dydrogesterone 10 mg 2 or 3 times daily, either between the 5th and 25th days of the menstrual cycle (prolonged cyclical treatment regimen) or continuously (continuous treatment regimen). For all patients, the data cutoff was at six months of treatment. MAIN OUTCOME MEASURE(S): Intensity of chronic pelvic pain on the 11-point numerical rating scale (after 6 months). RESULT(S): A marked reduction in chronic pelvic pain was observed with both the prolonged cyclical and continuous treatment regimens (mean ± standard deviation change from baseline -3.3 ± 2.2 and -3.0 ± 2.2, respectively), with no significant difference between the two groups. With both regimens, patients experienced significant improvements in the intensity of chronic pelvic pain, number of days in which analgesics were required, severity of dysmenorrhea, sexual well-being, and health-related quality-of-life parameters. A favorable safety profile of dydrogesterone was confirmed, and no serious adverse drug reactions were reported during the study. CONCLUSION(S): Prolonged cyclical and continuous treatment regimens of dydrogesterone therapy both demonstrated a pronounced and similar reduction in the severity of chronic pelvic pain and dysmenorrhea and led to marked improvements in all study parameters related to quality of life and sexual well-being. REGISTRATION NUMBER: NCT03690765.

Uterine Leiomyomas with an Apparently Normal Karyotype Comprise Minor Heteroploid Subpopulations Differently Represented in vivo and in vitro.

In the present study, we aimed to check whether uterine leiomyomas (ULs) with an apparently normal karyotype in vitro comprise "hidden" cell subpopulations with numerical chromosome abnormalities (heteroploid cells). A total of 32 ULs obtained from 32 patients were analyzed in the study. Each UL was sampled for in vivo and in vitro cytogenetic studies. Karyotyping was performed on metaphase preparations from the cultured UL samples. A normal karyotype was revealed in 20 out of the 32 ULs, of which 9 were selected for further study based on the good quality of the interphase preparations. Then, using interphase FISH with centromeric DNA probes, we analyzed the copy number of chromosomes 7 and 16 in 1,000 uncultured and 1,000 cultured cells of each selected UL. All of the ULs included both disomic cells representing a predominant subpopulation and heteroploid cells reaching a maximum frequency of 21.6% (mean 9.8%) in vivo and 11.5% (mean 6.1%) in vitro. The spectrum of heteroploid cells was similar in vivo and in vitro and mostly consisted of monosomic and tetrasomic cells. However, their frequencies in the cultured samples differed from those in the uncultured ones: while the monosomic cells decreased in number, the tetrasomic cells became more numerous. The frequency of either monosomic or tetrasomic cells both in vivo and in vitro was not associated with the presence of MED12 exon 2 mutations in the tumors. Our results suggest that ULs with an apparently normal karyotype consist of both karyotypically normal and heteroploid cells, implying that the occurrence of minor cell subpopulations with numerical chromosome abnormalities may be considered a characteristic of UL tumorigenesis. Different frequencies of heteroploid cells in vivo and in vitro suggest their dependence on microenvironmental conditions, thus providing a pathway for regulation of their propagation, which may be important for the UL pathogenesis.

Dopamine agonists as genital endometriosis target therapy.

OBJECTIVE: The present study was to find a pathogenic evidence for dopamine agonist application in patients with endometriosis associated pain syndrome. PATIENTS AND TECHNIQUE: The study involved 227 patients of reproductive age with histologically confirmed genital endometriosis (GE) of I-III degree according to ASRM classification. The control group included 12 women with no laparoscope detected gynecologic pathology. The levels of prolactin (PRL), peripheral blood (PB), and peritoneal fluid (PF) were evaluated by chemiluminescence immune assay. The pain syndrome was measured by McGill visual analogue scale. Statistica10 program (StatSoft, Inc., Tulsa, OK) was applied for obtained data processing. RESULTS: A correlation was established between GE rate and levels of PRL and PB (Rs = 0.28, p < .05) as well as a correlation of PRL in PB and PF (Rs = 0.29, p < .05). Patients receiving cabergoline combined with hormone therapy standard schemes manifested considerable pain syndrome relief. CONCLUSIONS: PRL involvement in GE pathogenesis and more intense therapeutic impact on pain syndrome in case of combined administration of dopamine and standard hormone therapy prove cabergoline application in clinical practice.

The potentialities of oxytocin receptor inhibitors for endometriosis therapy.

OBJECTIVE: Genital endometriosis (GE) is a widespread gynecological disease which requires its further pathogenesis investigation and search for new effective treatments. The known data of oxytocin receptor presence in endometrioid heterotopy smooth muscle cells give some grounds to assume oxytocin participation in the pathogenesis of endometriosis. The present study objective was to evaluate oxytocin level in peripheral blood (PB) in patients with endometriosis associated pain syndrome and to estimate the efficacy of oxytocin receptor inhibitors (IOXTR) administration based on animal endometriosis model. MATERIALS AND METHODS: The basic group comprised 61 patients with endometriosis associated pain syndrome, while 21 patients formed the control group. VAS, MPQ, and BBS objective tests were applied for pain syndrome evaluation. Oxytocin level in PB was measured by immunoenzyme method. After confirmation of endometriosis experimental model formation in rats and further randomization, a daily IOXTR intra-abdominal injection was performed in a dose of 0.35 mg/kg/24 h in the basic group (n = 12) or saline solution administration in the control (n = 12). On the final stage, endometrioid heterotopy size measuring was performed along with histological examination. RESULTS: Oxytocin level in PB was authentically higher in patients with GE compared to the control: 51.45 (35.54-62.76) pg/mL and 27.64 (23.23-34.12) pg/mL, respectively (p<.001). Positive correlation between oxytocin PB level and pain syndrome expression was established in patients with GE: VAS (r = 0.76; p<.001), MPQ (r = 0.52; p<.001), and BBS (r = 0.57; p<.001). Based on the experimental disease model authentical decrease of endometrioid heterotopy average area was observed after IOXTR therapy compared to the control (7.3 ± 1.8 mm2 and 22.2 ± 1.2 mm2, respectively, p<.05). CONCLUSIONS: The obtained results confirm the oxytocin role in the pathogenesis of endometrioid associated pain syndrome. The high efficacy of IOXTR administration based on animal model of surgically induced endometriosis allows viewing this method as a perspective therapy.

Use of dienogest in endometriosis: a narrative literature review and expert commentary.

Objective: Endometriosis affects up to 10% of women of reproductive age, and the main goal of treatment is to relieve symptoms. Progestins have been the mainstay of endometriosis suppression, of which dienogest has become an important option in many parts of the world. This is an expert literature review, with recommendations on the use of dienogest in the context of various clinical considerations when treating endometriosis.Methods: A search of PubMed was conducted for papers published between 2007 and 2019 on the use of dienogest in endometriosis. Experts reviewed these and included those they considered most relevant in clinical practice, according to their own clinical experience.Results: Evidence regarding the long-term use (>15 months) of dienogest for the management of endometriosis is presented, with experts concluding that the efficacy of dienogest should be assessed primarily on its impact on pain and quality of life. Fertility preservation, the option to avoid or delay surgery, and managing bleeding irregularities that can occur with this treatment are also considered. Counseling women on potential bleeding risks before starting treatment may be helpful, and evidence suggests that few women discontinue treatment for this reason, with the benefits of treatment outweighing any impact of bleeding irregularities.Conclusions: Overall, the evidence demonstrates that dienogest offers an effective and tolerable alternative or adjunct to surgery and provides many advantages over combined hormonal contraceptives for the treatment of endometriosis. It is important that treatment guidelines are followed and care is tailored to the woman's individual needs and desires.

Pathogenomics of Uterine Fibroids Development.

We review recent studies dealing with the molecular genetics and basic results of omics analysis of uterine leiomyoma (LM)-a common benign muscle tumor of the uterus. Whole genome studies of LM resulted in the discovery of many new gene nets and biological pathways, including its origin, transcriptomic, and epigenetic profiles, as well as the impact of the inter-cell matrix in LM growth and involvement of microRNA in its regulation. New data on somatic cell mutations ultimately involved in the origin, distribution and growth of LM are reviewed. Putative identification of LM progenitor SC (stem cells) giving rise to maternal fibroid nodes and junctional zones provide a new clue for hypotheses on the pathogenomics of LM. The reviewed data are consistent with at least two different but probably intimately interacted molecular mechanisms of LM. One of them (the genetic hypothesis) is focused primarily on the MED12 gene mutations and suggests its onset in the side population of embryonic myoblasts of the female reproductive system, which later gave rise to multiple small and medium fibroids. The single and usually large-size fibroids are induced by predominantly epigenetic disorders in LM SC, provoked by enhanced expression of the HMGA2 gene caused by its hypomethylation and epigenetic deregulation enhanced by hypoxia, muscle tension, or chromosome instability/aberrations. The pathogenomics of both genetic and epigenetic programs of LM with many peculiarities at the beginning later became rather similar and partly overlapped due to the proximity of their gene nets and epigenetic landscape. Pathogenomic studies of LM open ways for elaboration of novel strategies of prevention and treatment of this common disease.

Impact of Micronutrient Status during Pregnancy on Early Nutrition Programming.

BACKGROUND: Nutrition status prior to conception and during pregnancy and infancy seems to have an influence on the disease risk in adulthood (early nutrition/developmental programming). We aimed to review the current knowledge on the role of micronutrients in early nutrition programming and its implications for healthcare. SUMMARY OF FINDINGS: Globally and even in high-income countries where a balanced diet is generally accessible, an inadequate maternal micronutrient status is common. This may induce health problems in the mother and foetus/newborn both immediately and in later life. Pregnant women and those who may become pregnant should aim to achieve a satisfactory micronutrient status from a well-balanced diet, and where necessary from additional supplements. Key Messages: We emphasise the need for a call to action for healthcare providers and policymakers to better educate women of child-bearing age regarding the short- and long-term benefits of an appropriate micronutrient status. The role of micronutrient status in early nutrition programming needs to be emphasized more to address the still limited awareness of the potential long-term health repercussions of suboptimal micronutrient supply during pregnancy.

Pathogenomics of Endometriosis Development.

For over 100 years, endometriosis, as a chronic, estrogen-dependent, inflammatory, heritable disease affecting approximately 5⁻10% of women in reproductive age has been the focus of clinicians and scientists. In spite of numerous environmental, genetic, epigenetic, endocrine, and immunological studies, our knowledge of endometriosis is still fragmentary, and its precise pathophysiology and pathogenomics remain a mystery. The implementation of new technologies has provided tremendous progress in understanding the many intrinsic molecular mechanisms in the development of endometriosis, with progenitor and stem cells (SCs) of the eutopic endometrium as the starting players and endometriotic lesions as the final pathomorphological trait. Novel data on the molecular, genetic, and epigenetic mechanisms of the disease are briefly outlined. We hypothesize the existence of an endometriosis development genetic program (EMDP) that governs the origin of endometrium stem cells programmed for endometriosis (1), their transition (metaplasia) into mesenchymal SCs (2), and their invasion of the peritoneum and progression to endometriotic lesions (3). The pros and cons of the recent unifying theory of endometriosis are also discussed. Complex genomic and epigenetic interactions at different stages of the endometriosis process result in different forms of the disease, with specific features and clinical manifestations. The significance of the EMDP in elaborating a new strategy for endometriosis prediction, prevention, and treatment is discussed.

Dienogest treatment after ovarian endometrioma removal in infertile women prior to IVF.

BACKGROUND: Severe forms of genital endometriosis are known to be associated with infertility and its subsequent treatment failure. Both gonadotropin-releasing hormone analogs (a-GnRH) and dienogest have been suggested as additional hormone therapy for patients with endometriomas. However, the result of hormonal suppression before an in vitro fertilization (IVF) cycle remains undetermined. MATERIALS AND METHODS: A prospective cohort study of 144 infertile women planning IVF after laparoscopic surgery of ovarian endometriomas was conducted at our department in 2012-2015. Patients were divided into three groups: group I (N = 38) with dienogest course, group II (N = 70) with a-GnRH group III (N = 70) without any hormonal therapy within 6 months preceding IVF. RESULTS: The study groups did not differ by removed endometriomas size and ovarian reserve indicators. The gonadotropin dose per Cycle was higher, while the number of retrieved oocytes was lower in group III patients (p < .001). In women with dienogest pretreatment, clinical pregnancy rate was 2.5 times (44.7% versus 16.7%, p = .012) and delivery rate - three times higher (36.8% versus 11.1%, p = .013) as compared with those from group III. CONCLUSIONS: The present study confirms the necessity of pre-cycle medical interventions in women with ovarian forms of endometriosis undergoing IVF. We suggest dienogest to be possibly more efficient treatment option for this kind of patients.

Catechol-O-methyltransferase Val158Met polymorphism is associated with increased risk of multiple uterine leiomyomas either positive or negative for MED12 exon 2 mutations.

AIMS: To study the possible association of catechol-O-methyltransferase (COMT) Val158Met polymorphism with multiple and solitary uterine leiomyomas (ULs) and to check whether the COMT Val/Val genotype is associated with MED12 exon 2 mutations in fibroids. METHODS: The COMT Val158Met allele and genotype frequencies were compared between age-matched women with ULs (n=104) and controls (n=59). Patients with UL were subcategorised by diagnosis of solitary (n=59) or multiple (n=45) fibroids and by the presence of somatic MED12 exon 2 mutations in at least one fibroid (n=32) or in neither fibroid (n=26). The association of COMT Val/Val genotype with the presence of any ULs, solitary/multiple ULs and ULs positive/negative for MED12 exon 2 mutations was evaluated by χ2 tests using a dominant genotype model (G/G vs G/A+A/A) and expressed as ORs and 95% CIs. RESULTS: The COMT Val/Val genotype frequency did not differ between the patients with UL and the controls (28.8% vs 18.6%, p=0.149, OR 1.77; CI 0.81 to 3.86). However, it was significantly higher in the patients who had multiple UL compared with the solitary UL (40% vs 20.3%, p=0.028, OR 2.61; CI 1.09 to 6.24) and to the controls (40% vs 18.6%, p=0.016, OR 2.91; CI 1.20 to 7.06). No association of the COMT Val/Val genotype with UL-specific MED12 exon 2 mutations was found (p=0.662, OR 0.77; CI 0.23 to 2.53). CONCLUSIONS: Women with COMT Val/Val genotype are at high risk of developing multiple uterine fibroids either positive or negative for MED12 exon 2 mutations. These data are important to design new strategies for UL prophylaxis and treatment.

Comparative systems genetics view of endometriosis and uterine leiomyoma: Two sides of the same coin?

Endometriosis (EM) and uterine leiomyoma (UL) are two most frequent benign tumors of monoclonal origin affecting about 30% of all women in their reproductive age. Modern molecular technologies have made a tremendous impact in understanding both disorders. Here is the first comparative analysis of molecular mechanisms underlying development of EM and UL as it looks from the platform of systems genetics. Similarities and differences of EM and UL at their incipient stages are enlightened with special emphasis on their gene networks, gene expression, and epigenetic regulation, of pathologic development. The analysis substantiates a new hypothesis postulating tumors as outgrowths of the stem cells with mesenchymal commitment lineage (mSC) which migrate from the endometrium/myometrium junctional zone of the uterus. Comparative analysis has revealed basic similarities of molecular pathogenesis of EM and UL suggesting molecular syntropy of both disorders. Peculiarities of the epigenetic landscape determining development of mSC may explain the existence of different clinical forms of EM and UL as well as their unique clinical manifestation. Some perspectives for practical and scientific application in EM and UL studies of this new hypothesis are outlined.

Frequency and Spectrum of MED12 Exon 2 Mutations in Multiple Versus Solitary Uterine Leiomyomas From Russian Patients.

Uterine leiomyomas (ULs) are common benign tumors affecting women of different ethnicities. A large proportion of UL has mutations in MED12. Multiple and solitary ULs usually manifest with different severities, suggesting that their origin and growth pattern may be driven by different molecular mechanisms. Here, we compared the frequency and the spectrum of MED12 exon 2 mutations between multiple (n=82) and solitary (n=40) ULs from Russian patients. Overall, we detected MED12 exon 2 mutations in 51.6% (63/122) of ULs. The frequency of MED12 exon 2 mutations was almost two-fold higher in samples from the multiple UL patients than in those from the solitary UL patients - 61% (50/82) versus 32.5% (13/40). The increased MED12 exon 2 mutation frequency in the multiple ULs was not accompanied by significant alterations in the spectrum of mutation categories, which included missense mutations, deletions, splicing defects, and multiple (double/triple) mutations. Each mutation category had a unique mutation set, comprising both frequent and rarely encountered mutations, which did and did not overlap between the studied groups, respectively. We conclude that in contrast to the solitary ULs, the multiple ULs predominantly originate through MED12-associated mechanisms. The nature of these mechanisms seems to be similar in solitary and multiple ULs, as they contain similar mutations. In multiple UL patients, they are likely to be nonsporadic, indicating the existence of specific factors predisposing to multiple UL development. These data suggest that to clearly understand UL pathogenesis, solitary and multiple tumors should probably be analyzed as separate sets.

Systems genetics view of endometriosis: a common complex disorder.

Endometriosis is a condition in which cells derived from the endometrium grow outside the uterus, e.g. in the peritoneum (external genital endometriosis). As these cells are under the influence of female hormones, major symptoms of endometriosis are pain, especially during the cycle, and infertility. Numerous hypotheses for the formation of endometriosis can be found in the literature, but there is growing evidence of serious genetic contributions to endometriosis susceptibility. The involvement of genes, steroid hormone metabolism, immunological reactions, receptor formation, inflammation, proliferation, apoptosis, intercellular adhesion, cell invasion and angiogenesis as well as genes regulating the activity of aforementioned enzymes have been suggested. Some more recently suggested candidate genes picked up in genome-wide association studies are involved in oncogenesis, metaplasia of endometrium cells and pathways of embryonic development of the female reproductive system. However, gene mutations proven to be causative for endometriosis have not been identified so far, even though the abnormal expression of candidate genes for endometriosis could be provoked by different epigenetic modifications including DNA methylation, heterochromatization or introduction of regulatory miRNA. We hypothesize that endometriosis is induced by a combination of abnormal genetic and/or epigenetic mutations: the latter pave the way for pathological changes which become irreversible, and according to the "epigenetic landscape" theory, this proceeds to the typical clinical manifestations. Two stages in the endometriosis pathway are suggested: (1) induction of primary endometrial cells toward endometriosis, and (2) implantation and progression of these cells into endometriosis lesions. The model favors endometriosis as an outgrowth of primary cells different in their origin, canalization of pathological processes, manifestation diversity provoked by unique genetic background and epigenetic influences, which result in many different clinical forms of the disease.