Aim of the studyTo evaluate the frequency of MRE11/RAD50/NBS1 (MRN)-complex loss of protein expression in endometrial cancers (EC) and to determine whether loss of MRE11 renders the cancer cells sensitive to Poly(ADP-ribose) polymerase (PARP)-inhibitory treatment.MethodsMRN expression was examined in 521 samples of endometrial carcinomas and in 10 cancer cell lines. A putative mutation hotspot in the form of an intronic poly(T) allele in MRE11 was sequenced in selected cases (n = 26). Sensitivity to the PARP-inhibitor, BMN673 was tested in colony formation assays before and after MRE11 silencing using siRNA. Homologous recombination (HR) DNA repair was evaluated by RAD51-foci formation assay upon irradiation and drug treatment.ResultsLoss of MRE11 protein was found in 30.7% of EC tumours and significantly associated with loss of RAD50, NBS1 and mismatch repair protein expression. One endometrial cell line showed a markedly reduced MRE11 expression due to a homozygous poly(T) mutation of MRE11, thereby exhibiting an increased sensitivity to BMN673. MRE11 depletion sensitizes MRE11 expressing EC cell lines to the treatment with BMN673. The increased sensitivity to PARP-inhibition correlates with reduced RAD51 foci formation upon ionizing radiation in MRE11-depleted cells.ConclusionLoss of the MRE11 protein predicts sensitivity to PARP-inhibitor sensitivity in vitro, defining it as an additional synthetic lethal gene with PARP. The high incidence of MRE11 loss in ECs can be potentially exploited for PARP-inhibitor therapy. Furthermore, MRE11 protein expression using immunohistochemistry could be investigated as a predictive biomarker for PARP-inhibitor treatment.
Kisspeptins, the peptide products of the KiSS-1 gene, bind to the G protein coupled receptor 54 (GPR54). Since 2003, research has revealed the important role of kisspeptins in initiating puberty, timing puberty and regulating fertility in adulthood. Specific mutations in GPR54 gene cause either delayed/absent puberty or precocious puberty. The KiSS-1/GPR54 system stimulates the gonadotrophin releasing hormone (GnRH) neurons and is involved in the feedback regulation of the HPG axis by gonadal steroids. Different hypothalamic nuclei are involved in negative (arcuate nucleus; ARC) and positive (anteroventral periventricular nucleus; AVPV) feedback in mice. Continuous administration of kisspeptins down-regulates the HPG axis. During pregnancy, kisspeptins are secreted from the placenta in large amounts and are responsible for the physiological invasion of primary human trophoblast. Kisspeptins have been administered to normal male and female individuals as well as to women with hypothalamic secondary amenorrhoea. In all cases, gonadotrophin secretion was potently stimulated. Kisspeptin antagonists have been synthesized to successfully suppress GnRH and gonadotrophin release. These agonists and antagonists appear as valuable new tools for manipulating the HPG axis and are promising drugs for future treatment. The scope of this review highlights the role of kisspeptins in regulating gonadotrophin secretion and explores their possible therapeutic use.
Histone deacetylase (HDAC) inhibitors such as vorinostat (suberoylanilide hydroxamic acid), valproic acid, romidepsin , and LBH589 comprise a relatively new class of potent anticancer agents. This study provides evidence for the potential of vorinostat to cause acquisition of multidrug resistance protein-independent resistance in HCT116 colon tumor cells. This acquired resistance is moderate (two-fold to three-fold), is nonreversible, and correlates with the loss of responses typically seen with HDAC inhibitors, that is the loss of acetylation of the histones H2A, H2B, H3, and H4, the loss of the G2/M checkpoint activation, and the loss of caspase 3-dependent and caspase 7-dependent apoptosis. This acquired resistance also associates with cross-resistance to the hydroxamate-class (LBH589 and JNJ26481585) and to the aliphatic acid-class (valproic acid) HDAC inhibitors but not to the benzamideclass (MGCD0103) and the cyclic peptide-class (romidepsin) HDAC inhibitors. The acquired HDAC inhibitor resistance described hereis not a result of altered HDAC and histone acetyltransferase activities and differs from that previously reported for romidepsin. The present study provides evidence for the potential of vorinostat to cause acquisition of MDRindependent resistance in HCT116 colon tumor cells. This acquired resistance is moderate (2 to 3-fold), is non-reversible, and correlates with the loss of responses typically seen with HDAC inhibitors, i.e. the loss of acetylation of the histones H2A, H2B, H3, and H4, the loss of the G2/M checkpoint activation, and the loss of caspase 3-and caspase 7-dependent apoptosis. This acquired resistance also associates with cross-resistance to the hydroxamate-class (LBH589 and JNJ26481585) and to the aliphatic acid-class (VPA) HDAC inhibitors but not to the benzamideclass (MGCD0103) and the cyclic peptide-class (romidepsin) HDAC inhibitors. The herein described acquired HDAC inhibitor resistance is not due to altered HDAC and HAT activities and differs from that previously reported for romidepsin.
Circular isthmic-cervical suture is a quick, safe, simple and effective technique for controlling peripartum haemorrhage during caesarean section for placenta praevia accreta.
CM performed by an experienced obstetrician can be safe in selected patients who are without additional preexisting risk factors. Risk factors that are associated with increased blood loss in women with uterine leiomyomatas include a larger size of the leiomyoma (≥5 cm) and a maternal age of ≥40 years.
Background There is a growing body of human, animal and in vitro studies on vitamin D (vit D) substitution in endometriosis. The aim of this systematic review is to critically appraise and qualitatively synthesize the results of the available studies that examine the supplementation of vit D for endometriosis treatment. Methods A systematic search of the literature was conducted in four electronic databases (Medline, Cochrane, Scopus, Embase) and grey literature for original research articles on humans, animals and in vitro models published in any language. Results Four human studies, four animal studies and four in vitro studies were included. Quantitative synthesis of human studies showed no significant effect of vit D intake for dysmenorrhea (2 studies, 44 vit D vs 44 placebo, mean -0.71, 95% CI -1.94, 0.51) and non-cyclic pelvic pain (2 studies, 42 vit D vs 38 placebo, mean 0.34, 95% CI -0.02, 0.71). Regarding reproductive outcomes in women with endometriosis after in vitro fertilization, the only available study showed no differences between women taking vit D and women taking placebo. Three of the four included animal studies showed regression of endometriotic implants when treated with vit D. The in vitro studies demonstrated that vit D decreases invasion and proliferation of endometriotic lesions without affecting apoptosis. Conclusions Although in vitro and animal studies suggest regression of the endometriotic implants and decrease of invasion and proliferation after vit D supplementation, this was not reflected in the results of the meta-analysis, which showed no benefit of vit D supplementation in patients with endometriosis and dysmenorrhea or non-cyclic pelvic pain as well as on the outcome of IVF treatment. However, given the heterogeneity and the diversity of the available studies, more research is required to shed light on the role of vit D supplementation in women with endometriosis.
PurposeTo determine if models of ovarian clear cell carcinomas (OCCCs) harbouring defects in homologous recombination (HR) DNA repair of double strand breaks (DSBs) are sensitive to cisplatin and/or PARP inhibition.Experimental DesignThe HR status of 12 OCCC cell lines was determined using RAD51/γH2AX foci formation assays. Sensitivity to cisplatin and the PARP inhibitor BMN-673 was correlated with HR status. BRCA1, BRCA2, MRE11 and PTEN loss of expression was investigated as a potential determinant of BMN-673 sensitivity. A tissue microarray containing 50 consecutive primary OCCC was assessed for PTEN expression using immunohistochemistry.ResultsA subset of OCCC cells displayed reduced RAD51 foci formation in the presence of DNA DSBs, suggestive of HR defects. HR-defective OCCC cells, with the exception of KOC-7c, had higher sensitivity to cisplatin/ BMN-673 than HR-competent OCCC cell lines (Log10 SF50 –9.4 (SD +/− 0.29) vs –8.1 (SD +/− 0.35), mean difference 1.3, p < 0.01). Of the cell lines studied, two, TOV-21G and KOC-7c, showed loss of PTEN expression. In primary OCCCs, loss of PTEN expression was observed in 10% (5/49) of cases.ConclusionsA subset of OCCC cells are sensitive to PARP inhibition in vitro, which can be predicted by HR defects as defined by γH2AX/RAD51 foci formation. These results provide a rationale for the testing of HR deficiency and PARP inhibitors as a targeted therapy in a subset of OCCCs.
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