BackgroundEndometriosis is a common, benign, and estrogen-dependent disease characterized by pelvic pain and infertility. To date, the pathogenesis of endometriosis remains unclear. Recent studies have demonstrated that noncoding RNAs, including microRNAs and long noncoding RNAs, play important roles in the development of endometriosis.MethodsExpression profiling of miRNAs in endometrial tissue was characterized using microarrays. The most differentially expressed miRNAs were confirmed using quantitative reverse transcriptase-polymerase chain reaction analysis in additional ectopic endometrial (n = 27) and normal endometrial (n = 12) tissues. For in-vitro functional studies, 5-ethynyl-2′-deoxyuridine incorporation assay, Transwell assay, and dual-luciferase reporter assay were used to measure the proliferation, migration, and luciferase activity of miR-200c and the predicted targets of miR-200c in primary endometrial stromal cells (HESCs) derived from human endometrial biopsies, respectively. For in-vivo therapeutic interventions, polymeric nanoparticles of polyethylenimine–polyethylene glycol–arginine–glycine–aspartic acid were used for delivery of miR-200c mimic and inhibitor to determine the therapeutic effect of miR-200c in a rat model of endometriosis.ResultsExogenous overexpression of miR-200c inhibited the proliferation and migration of HESCs, which were mainly regulated by metastasis-associated lung adenocarcinoma transcript 1 (MALAT1). In contrast, inhibition of miR-200c promoted the proliferation and migration of HESCs, while the simultaneous silencing of MALAT1 expression exerted the opposite effects. We demonstrated that expression of MALAT1 in ectopic endometrial specimens was negatively correlated with that of miR-200c and that MALAT1 knockdown increased the level of miR-200c in HESCs. Moreover, the transfection of endometrial stromal cells with the miR-200c mimic or MALAT1 siRNAs decreased the protein levels of mesenchymal markers ZEB1, ZEB2, and N-cadherin and increased the protein levels of the epithelial marker E-cadherin. Furthermore, using a rat endometriosis model, we showed that local delivery of the miR-200c mimic significantly inhibited the growth of ectopic endometriotic lesions.ConclusionsThe MALAT1/miR-200c sponge may be a potential therapeutic target for endometriosis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13287-017-0706-z) contains supplementary material, which is available to authorized users.

Nucleotide excision repair (NER), the core mechanism of DNA repair pathway, was commonly used to maintain genomic stability and prevent tumorigenesis. Previous investigations have demonstrated that single nucleotide polymorphisms (SNPs) of NER pathway genes were associated with various types of cancer. However, there was no research elucidating the genetic association of entire NER pathway with ovarian cancer susceptibility. Therefore, we conducted genotyping for 17 SNPs of six NER core genes (XPA, XPC, XPG, ERCC1, ERCC2, and ERCC4) in 89 ovarian cancer cases and 356 cancer-free controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to describe the strength of association. The result showed that both ERCC1 rs11615 and XPC rs2228000 were significantly associated with reduced risk of ovarian cancer under dominant genetic model (adjusted OR = 0.35, 95% CI = 0.20–0.61, P=0.0002 and adjusted OR = 0.49, 95% CI = 0.30–0.81, P=0.005 respectively). In addition, XPC rs2228001 and ERCC2 rs238406 had statistically significant association with the increased risk of ovarian cancer under dominant genetic model (adjusted OR = 1.72, 95% CI = 1.02–2.92, P=0.043 and adjusted OR = 2.07, 95% CI = 1.07–4.01, P=0.032 respectively). ERCC1 rs3212986 were related with the increased risk of ovarian cancer under recessive model (adjusted OR = 2.40, 95% CI = 1.30–4.44, P=0.005). In conclusion, our results indicated that ERCC1, XPC and ERCC2 might influence ovarian cancer susceptibility. Further research with large sample size is warranted to validate the reliability and accuracy of our results.

Endometriosis is a chronic disorder characterized by the implantation of endometrial glands and stroma outside the uterus. However, the pathogenesis of endometriosis is still unclear. To date, there is no fully effective treatment without trauma because of various side effects. Recent data suggest that ferroptosis is a novel recognized form of nonapoptosis-regulated cell death characterized by iron-dependent and lethal lipid peroxidation accumulation, showing great promise in the treatment of many diseases. In the present study, we verified that erastin induced ferroptosis in ectopic endometrial stromal cells (EESCs). Furthermore, we found that the expression of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was decreased during erastin-induced ferroptosis. Knockdown of MALAT1 significantly aggravated the inhibition of cell viability and increased intracellular iron, Liperfluo, and MDA levels in EESCs upon erastin treatment. Mechanistically, we demonstrated that MALAT1 served as a competing endogenous RNA of miR-145-5p to regulate the expression of MUC1, a suppressor of ferroptosis. MALAT1 knockdown-mediated ferroptotic cell death and MUC1 downregulation could be abrogated by inhibition of miR-145-5p. In addition, miR-145-5p inhibition-mediated ferroptotic cell death could be abolished by MUC1 knockdown. Furthermore, erastin-induced ferroptosis shrunk endometriotic lesions via the MALAT1/miR-145-5p/MUC1 axis in vivo. Taken together, our data indicate that knockdown of MALAT1 facilitates ferroptosis upon erastin treatment via miR-145-5p/MUC1 signaling. The synergistic effect of MALAT1 knockdown and erastin induction in ferroptosis may be a new therapeutic strategy for endometriosis.

Background: Endometrial cancer is the most common gynecologic malignancy worldwide. Polymorphisms in MALAT1 have been demonstrated to play critical roles in cancer. However, the roles of MALAT1 polymorphisms in the etiology of endometrial cancer have not been well documented. Methods:We genotyped three MALAT1 polymorphisms in 249 endometrial cancer cases and 446 cancer-free female controls using quantitative polymerase chain reaction with TaqMan probes. To estimate the association between MALAT1 polymorphisms (rs591291 C>T, rs664589 C>G, and rs4102217 G>C) and the risk of endometrial cancer, an unconditional logistic regression model was conducted to calculate the odds ratio (OR) and the 95% confidence interval (CI), adjusting for surgery history, menopause, number of deliveries, BMI, and FIGO stage. Results:We found that the MALAT1 rs664589 C>G polymorphism was significantly associated with endometrial cancer risk (heterogeneous: adjusted OR = 0.57, 95% CI = 0.34-0.93, P = .026; homogenous: adjusted OR = 3.74, 95% CI = 1.12-12.45, P = .032; and recessive: adjusted OR = 4.06, 95% CI = 1.22-13.48, P = .022). Stratified analysis further demonstrated that the MALAT1 rs664589 C>G polymorphism significantly increased the risk of endometrial cancer susceptibility in patients with no history of surgery, more deliveries, BMI between 25 and 29.9, and FIGO stages II-III.Compared with the wild-type GCG haplotype carriers, individuals with CGG haplotypes had a higher risk of developing endometrial cancer. Conclusion:The MALAT1 rs664589 C>G polymorphism was associated with a significant increase in endometrial cancer risk. K E Y W O R D S endometrial cancer, MALAT1, risk, single nucleotide polymorphisms 2 of 7 | CHEN Et al.1 | INTRODUC TI ON Endometrial cancer (EC) is the most common cancer among females worldwide. 1 The incidence of EC has seen a significant increase in China. 2 Unopposed estrogen, early menarche, endometriosis, obesity, diabetes, late menopause, hypertension, and nulliparity are now well established as causative agents responsible for endometrial cancer. 3 Although these risk factors are strongly associated with the risk of endometrial cancer, only a small number of women eventually develop endometrial cancer, suggesting that host genetic variations play critical roles in endometrial cancer development.Long non-coding RNAs (lncRNAs) are a class of ncRNAs that are more than 200 nucleotides and are involved in several biological processes. [4][5][6][7][8] Increasing evidence suggests that lncRNAs are associated with tumor genesis, progress, and treatment response. 9,10 Metastasis associated with lung adenocarcinoma transcript-1 (MALAT1) is a long intergenic non-coding RNA (lincRNA), consisting of more than 8000 nts and located on chromosome 11q13. 11,12 Recent studies have shown that abnormal MALAT1 expression influenced cancer cell proliferation, invasion, and/or metastasis in various tumors, such as breast cancer, 13 lung cancer, 14 and gastric cancer. 15 Therefore, MALAT1 has been classified as an oncogene...

Mouse double minute 4 (MDM4) is a p53-interacting oncoprotein that plays an important role in the p53 tumor suppressor pathway. The common rs4245739 A > C polymorphism creates a miR-191 binding site in the MDM4 gene transcript. Numerous studies have investigated the association between this MDM4 polymorphism and cancer risk, but have failed to reach a definitive conclusion. To address this issue, we conducted a meta-analysis by selecting eligible studies from MEDLINE, EMBASE, and Chinese Biomedical databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. We also performed genotype-based mRNA expression analysis using data from 270 individuals retrieved from public datasets. A total of 15 studies with 19796 cases and 49681 controls were included in the final meta-analysis. The pooled results revealed that the MDM4 rs4245739C allele is associated with a decreased cancer risk in the heterozygous (AC vs. AA: OR = 0.82, 95% CI = 0.73−0.93), dominant (AC/CC vs. AA: OR = 0.82, 95% CI = 0.72−0.93), and allele contrast models (C vs. A: OR = 0.84, 95% CI = 0.76−0.94). The association was more prominent in Asians and population-based studies. We also found that the rs4245739C allele was associated with decreased MDM4 mRNA expression, especially for Caucasians. Thus the MDM4 rs4245739 A > C polymorphism appears to be associated with decreased cancer risk. These findings would be strengthened by new studies with larger sample sizes and encompassing additional ethnicities.