Epigenomic Analysis Reveals the KCNK9 Potassium Channel as a Potential Therapeutic Target for Adenomyosis

Adenomyosis is linked to dysmenorrhea and infertility. The pathogenesis of adenomyosis remains unclear, and little is known of the genetic and epigenetic changes in the eutopic endometrium in adenomyosis, which may predispose patients to the invasion and migration of endometrial tissues into the myometrium. Transcriptome studies have identified genes related to various cell behaviors but no targets for therapeutic intervention. The epigenetics of the eutopic endometrium in adenomyosis have rarely been investigated. Endometrial tissue was obtained from premenopausal women with (n = 32) or without adenomyosis (n = 17) who underwent hysterectomy aged 34–57 years at a tertiary hospital. The methylome and transcriptome were assessed by using a Methylation 450 K BeadChip array and Affymetrix expression microarray. Protein expression was examined by immunohistochemistry. Differential methylation analysis revealed 53 lowly methylated genes and 176 highly methylated genes with consistent gene expression in adenomyosis, including three genes encoding potassium ion channels. High expression of KCNK9 in the eutopic and ectopic endometria in patients with adenomyosis but not in normal controls was observed. Hormone-free, antibody-based KCNK9 targeting is a potential therapeutic strategy for adenomyosis-related dysmenorrhea, menorrhagia, and infertility.

Genome-wide analysis of cervical secretions obtained during embryo transfer reveals the association between deoxyribonucleic acid methylation and pregnancy outcomes

OBJECTIVE

To study whether the methylation status of cervical secretions can reflect the ability of the endometrium to allow embryo implantation.

DESIGN

Case-control study.

SETTING

In vitro fertilization centers.

PATIENT(S)

Women undergoing embryo transfer cycles, in which at least 1 good-quality embryo was transferred.

INTERVENTION(S)

Collection of cervical secretions during the procedure of embryo transfer.

MAIN OUTCOME MEASURE(S)

Methylation profiles of cervical secretions in relation to pregnancy outcomes.

RESULT(S)

Genome-wide methylation profiles differ between cervical secretions from pregnancy and nonpregnancy cycles. Clustering analysis on the basis of the top 2,000 differentially methylated probes of cervical secretions from 28 pregnancy and 29 nonpregnancy cycles correctly categorized 86.0% of the samples in terms of conceptional status, which was verified in selected genes by quantitative methylation-specific polymerase chain reaction and validated in another independent sample set. The combination of selected genes was estimated to predict pregnancy outcomes with a maximal area under the receiver operating characteristic curve of 0.83.

CONCLUSION(S)

The methylation profiles of cervical secretions were associated with pregnancy outcomes in embryo transfer cycles. Although not clinically useful at present, deoxyribonucleic acid methylation in cervical secretions may shed new light on the less invasive assessment of endometrial receptivity.

P–522 Cervical secretion methylation profile is associated with the success of frozen-thawed embryo transfer - a proof-of-concept study

Study question

Is cervical secretion gene methylation profile different between receptive and non-receptive endometrium and associated with implantation outcome in frozen-embryo transfer (FET) cycle?

Summary answer

The combination of candidate genes methylation profiles obtained from cervical secretion showed significant associations with pregnancy outcomes.

What is known already

Implantation failure remains a black box in reproductive medicine, and the exact mechanism of how endometrial receptivity is regulated is still unknown. Epigenetic modifications play a role in the gene expression pattern and may alter the endometrial receptivity in the human endometrium. Cervical secretion containing various implantation-related cytokines, and the gene methylation change can be used as a non-invasive molecular source that reflects the endometrium condition.

Study design, size, duration

In this retrospective case-control study, sixty-two women who entered the FET cycle (30 pregnant and 32 non-pregnant women) were enrolled.

Participants/materials, setting, methods

Cervical secretion was collected before embryo transfer from women enrolled in multicenter university-affiliated reproductive units. The DNA methylation status of six candidate genes was measured using quantitative methylation-specific PCR (qMSP). The correlation between methylation change and the pregnancy outcome was analyzed.

Main results and the role of chance

The candidate genes were selected from that associated with implantation with literature review and the original genome-wide DNA methylation data from NCBI GEO DataSets (GSE90060) which processed using bioinformatics analysis. Six candidate genes whose CpG-level methylation analysis with β-value statistically higher in receptive endometrium than in a pre-receptive endometrium were selected. All six candidate genes showed different degrees of correlation with the pregnancy outcomes. Among them, PRKAG2 methylation changes showed the highest correlation with the pregnancy outcome. A logistic regression model was used to evaluate the performance of a single gene or a combination of genes for implantation prediction. The results showed a statistically significant association between the methylation status of a combination of genes (PRKAG2, KRS1, HAND2) and the pregnancy outcome (p = 0.008), resulting in an optimal AUC of 0.7 (95% CI: 0.57 - 0.81) for implantation prediction.

Limitations, reasons for caution

The results obtained from a relatively small cohort size. A larger study and further comprehensive methylome investigations are warranted.

Wider implications of the findings: This study is the first proof-of-concept study that cervical secretion methylation profile is associated with implantation outcome in a FET cycle, and showed potential as a non-invasive method for implantation prediction.

Trial registration number

non applicable

NKX6-1 mediates cancer stem-like properties and regulates sonic hedgehog signaling in leiomyosarcoma

Background

Leiomyosarcoma (LMS), the most common soft tissue sarcoma, exhibits heterogeneous and complex genetic karyotypes with severe chromosomal instability and rearrangement and poor prognosis.

Methods

Clinical variables associated with NKX6-1 were obtained from The Cancer Genome Atlas (TCGA). NKX6-1 mRNA expression was examined in 49 human uterine tissues. The in vitro effects of NXK6-1 in LMS cells were determined by reverse transcriptase PCR, western blotting, colony formation, spheroid formation, and cell viability assays. In vivo tumor growth was evaluated in nude mice.

Results

Using The Cancer Genome Atlas (TCGA) and human uterine tissue datasets, we observed that NKX6-1 expression was associated with poor prognosis and malignant potential in LMS. NKX6-1 enhanced in vitro tumor cell aggressiveness via upregulation of cell proliferation and anchorage-independent growth and promoted in vivo tumor growth. Moreover, overexpression and knockdown of NKX6-1 were associated with upregulation and downregulation, respectively, of stem cell transcription factors, including KLF8, MYC, and CD49F, and affected sphere formation, chemoresistance, NOTCH signaling and Sonic hedgehog (SHH) pathways in human sarcoma cells. Importantly, treatment with an SHH inhibitor (RU-SKI 43) but not a NOTCH inhibitor (DAPT) reduced cell survival in NKX6-1-expressing cancer cells, indicating that an SHH inhibitor could be useful in treating LMS. Finally, using the TCGA dataset, we demonstrated that LMS patients with high expression of NKX6-1 and HHAT, an SHH pathway acyltransferase, had poorer survival outcomes compared to those without.

Conclusions

Our findings indicate that NKX6-1 and HHAT play critical roles in the pathogenesis of LMS and could be promising diagnostic and therapeutic targets for LMS patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-021-00726-6.

Transition from multiport to single-site surgery: A single institution experience in robotic supracervical hysterectomy for benign gynecological diseases

OBJECTIVE

To share our experience of transition from multiport to single-site robotic surgery for benign gynecological conditions as well as to assess the selection criteria of candidates for robotic single-site supracervical hysterectomy (RSSH).

MATERIALS AND METHODS

A retrospective review was conducted on patients undergoing robotic supracervical hysterectomy by a single surgeon in a single institute between June 2014 and December 2017. Patients who underwent additional procedures along with supracervical hysterectomy and who had unexpectant corpus malignancy proved pathologically were excluded from comparisons between patients undergoing RSSH and robotic multiport supracervical hysterectomy (RMSH).

RESULTS

Between June 2014 and December 2017, we accomplished 26 RSSH and 57 RMSH. There were no conversions, intraoperative complications, and readmissions within 30 days after surgery. In the RSSH group, the mean uterine weight was 264.6 ± 140.9 g with mean docking time of 15.8 ± 5.5 min, mean console time of 61.1 ± 35.6 min and mean operative time of 140.3 ± 34.4 min. In comparison to the RMSH group, the percentage of overweight/obese patients was lower (p = 0.018) and the uterine size was smaller (p < 0.001) with adenomyosis diagnosed more frequently (p = 0.002) in the RSSH group. While the operative time in the RSSH group was significantly shorter (p = 0.002), the RSSH group took longer time in docking (p < 0.001) and comparable time in console (p = 0.254). In view of chronological change, docking time and console time in the RMSH group remained steady, whereas steep decreases were observed in the RSSH group. The intraoperative blood loss and hemoglobin drop were comparable. The length of hospital stay was significantly shorter in the RSSH group (p = 0.005).

CONCLUSION

Transition from multiport to single-site surgery can be smooth for a surgical team experienced in the conventional multiport robotic system. RSSH is safe and feasible in properly selected patients.

Efficacy and safety of core stability training on gait of children with cerebral palsy: A protocol for a systematic review and meta-analysis

BACKGROUND

Cerebral palsy (CP) is a common disability in children featured with pathological gait and limb function limitation due to muscle weakness. Improving limb function and quality of life is currently considered to be highlighted. Physiotherapy is a chief component of rehabilitation for children with CP, correcting gait and improve walking capacity through muscle strength training. Standard rehabilitation programs for CP have not been determined. Core stability training (CST), which coordinates limb balance via trunk control, is widely used in sports competition. And it is gradually introduced into the rehabilitation of children with cerebral palsy with a positive impact on the patients' gait performance. By screening published literatures, this study aims to conduct a meta-analysis to systematically evaluate the effectiveness and safety of CST in gait of children with CP.

METHODS

Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on CST in the treatment of children with CP were searched from 6 databases. Moreover, the reference lists of conference papers and included literatures will be manually searched to avoid omissions. Literature screening and data extraction were performed independently by 2 researchers. RCTs carry out the risk of bias analysis evaluation from seven aspects through the Cochrane Collaboration's risk of bias tool. Fixed or random effect model will be performed to analyze the outcomes. When higher heterogeneity occurs (I > 50%), the sensitivity or subgroup analysis will also be conducted to find potential factors. And the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach is used for assessing the quality of evidence.

RESULTS

The study will evaluate the effect of CST on gait of children with CP from multiple outcomes, including walking speed, endurance, stride length, and safety.

CONCLUSION

Based on evidence-based medicine, the conclusion of this study can demonstrate the effectiveness and safety of CST in gait correction for children with CP.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD 42019134094.

Ovarian cancer detection by DNA methylation in cervical scrapings

Background

Ovarian cancer (OC) is the most lethal gynecological cancer, worldwide, largely due to its vague and nonspecific early stage symptoms, resulting in most tumors being found at advanced stages. Moreover, due to its relative rarity, there are currently no satisfactory methods for OC screening, which remains a controversial and cost-prohibitive issue. Here, we demonstrate that Papanicolaou test (Pap test) cervical scrapings, instead of blood, can reveal genetic/epigenetic information for OC detection, using specific and sensitive DNA methylation biomarkers.

Results

We analyzed the methylomes of tissues (50 OC tissues versus 6 normal ovarian epithelia) and cervical scrapings (5 OC patients versus 10 normal controls), and integrated public methylomic datasets, including 79 OC tissues and 6 normal tubal epithelia. Differentially methylated genes were further classified by unsupervised hierarchical clustering, and each candidate biomarker gene was verified in both OC tissues and cervical scrapings by either quantitative methylation-specific polymerase chain reaction (qMSP) or bisulfite pyrosequencing. A risk-score by logistic regression was generated for clinical application.

One hundred fifty-one genes were classified into four clusters, and nine candidate hypermethylated genes from these four clusters were selected. Among these, four genes fulfilled our selection criteria and were validated in training and testing set, respectively. The OC detection accuracy was demonstrated by area under the receiver operating characteristic curves (AUCs) in 0.80–0.83 of AMPD3, 0.79–0.85 of AOX1, 0.78–0.88 of NRN1, and 0.82–0.85 of TBX15. From this, we found OC-risk score, equation generated by logistic regression in training set and validated an OC-associated panel comprising AMPD3, NRN1, and TBX15, reaching a sensitivity of 81%, specificity of 84%, and OC detection accuracy of 0.91 (95% CI, 0.82–1) in testing set.

Conclusions

Ovarian cancer detection from cervical scrapings is feasible, using particularly promising epigenetic biomarkers such as AMPD3/NRN1/TBX15. Further validation is warranted.

[Research rules of famous veteran traditional Chinese medicine practitioners in treating infertility]

To explore the medication rules of famous veteran traditional Chinese medicine practitioners in treating infertility based on medical cases of infertility collected from book series of Hundred Traditional Chinese Medicine Clinicians of Hundred Years in China and Prescription Proven by Traditional Chinese Medicine Masters. Researchers extracted the information of prescriptions from these cases according to the inclusion and exclusion criteria. Then, Excel 2010, SPSS Clementine(ver.12.0) and SPSS(ver. 22.0) were adopted respectively for frequency analysis, association rules analysis, cluster analysis and factor analysis. Cluster analysis was carried out by Ochiai algorithm of binary variable data, which was a systematic clustering method. And principal component analysis was used for factor analysis. Besides, KMO test and Bartlett spherical test were used for factor adaptation test. Finally, 151 medical cases and 396 prescriptions were included in total. A total of 60 kinds of frequently used herbs were identified according to the results of frequency analysis for medication, they were mainly used for activating blood and resolving stasis, tonifying and clearing heat respectively. The association rules analysis found out 25 drug pair association rules and 14 3-drug combination association rules. A total of 15 medicine groups were extracted by cluster analysis. KMO test and Bartlett spherical test indicated that the method was suitable for factor analysis, and 21 common factors were respectively extracted by factor analysis. Association rules indicated the characteristics of the therapeutic methods, like tonifying Qi and replenishing blood. The famous veteran traditional Chinese medicine practitioners utilized modified Siwu Decoction for tonifying blood and preferred Atractylodis Macrocephalae Rhizoma(Baizhu) for tonifying Qi. The results of both cluster analysis and factor analysis demonstrated the characteristics of the therapies for tonifying kidney, activating blood, tonifying spleen and dispelling dampness. In addition, factor analysis could reflect the therapies for nourishing Yin, tonifying kidney, warming the meridian, dissipating cold, nourishing blood and dispelling blood stasis. These results of analysis comprehensively showed out the medication characteristics of famous veteran traditional Chinese medicine practitioners of strictly following the pathogenesis, making good use of classical formulas and providing proper compatibility. In conclusion, data mining techniques(including frequency analysis, association rules analysis, cluster analysis and factor analysis) were used to comprehensively analyze the medication rules of famous veteran traditional Chinese medicine practitioners in treating infertility, which is helpful for guiding the clinical practice of treating infertility with traditional Chinese medicine.

The role of GRHL2 and epigenetic remodeling in epithelial-mesenchymal plasticity in ovarian cancer cells

Cancer cells exhibit phenotypic plasticity during epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET) involving intermediate states. To study genome-wide epigenetic remodeling associated with EMT plasticity, we integrate the analyses of DNA methylation, ChIP-sequencing of five histone marks (H3K4me1, H3K4me3, H3K27Ac, H3K27me3 and H3K9me3) and transcriptome profiling performed on ovarian cancer cells with different epithelial/mesenchymal states and on a knockdown model of EMT suppressor Grainyhead-like 2 (GRHL2). We have identified differentially methylated CpG sites associated with EMT, found at promoters of epithelial genes and GRHL2 binding sites. GRHL2 knockdown results in CpG methylation gain and nucleosomal remodeling (reduction in permissive marks H3K4me3 and H3K27ac; elevated repressive mark H3K27me3), resembling the changes observed across progressive EMT states. Epigenetic-modifying agents such as 5-azacitidine, GSK126 and mocetinostat further reveal cell state-dependent plasticity upon GRHL2 overexpression. Overall, we demonstrate that epithelial genes are subject to epigenetic control during intermediate phases of EMT/MET involving GRHL2.

TET1 reprograms the epithelial ovarian cancer epigenome and reveals casein kinase 2α as a therapeutic target

Ten-eleven translocation methylcytosine dioxygenase-1, TET1, takes part in active DNA demethylation. However, our understanding of DNA demethylation in cancer biology and its clinical significance remain limited. This study showed that TET1 expression correlated with poor survival in advanced-stage epithelial ovarian carcinoma (EOC), and with cell migration, anchorage-independent growth, cancer stemness, and tumorigenicity. In particular, TET1 was highly expressed in serous tubal intraepithelial carcinoma (STIC), a currently accepted type II EOC precursor, and inversely correlated with TP53 mutations. Moreover, TET1 could demethylate the epigenome and activate multiple oncogenic pathways, including an immunomodulation network having casein kinase II subunit alpha (CK2α) as a hub. Patients with TET1^high CK2α^high EOCs had the worst outcomes, and TET1-expressing EOCs were more sensitive to a CK2 inhibitor, both in vitro and in vivo. Our findings uncover the oncogenic and poor prognostic roles of TET1 in EOC and suggest an unexplored role of epigenetic reprogramming in early ovarian carcinogenesis. Moreover, the immunomodulator CK2α represents a promising new therapeutic target, warranting clinical trials of the tolerable CK2 inhibitor, CX4945, for precision medicine against EOC. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

E2F6 functions as a competing endogenous RNA, and transcriptional repressor, to promote ovarian cancer stemness

Ovarian cancer is the most lethal cancer of the female reproductive system. In that regard, several epidemiological studies suggest that long‐term exposure to estrogen could increase ovarian cancer risk, although its precise role remains controversial. To decipher a mechanism for this, we previously generated a mathematical model of how estrogen‐mediated upregulation of the transcription factor, E2F6, upregulates the ovarian cancer stem/initiating cell marker, c‐Kit, by epigenetic silencing the tumor suppressor miR‐193a, and a competing endogenous (ceRNA) mechanism. In this study, we tested that previous mathematical model, showing that estrogen treatment of immortalized ovarian surface epithelial cells upregulated both E2F6 and c‐KIT, but downregulated miR‐193a. Luciferase assays further confirmed that microRNA‐193a targets both E2F6 and c‐Kit. Interestingly, ChIP‐PCR and bisulphite pyrosequencing showed that E2F6 also epigenetically suppresses miR‐193a, through recruitment of EZH2, and by a complex ceRNA mechanism in ovarian cancer cell lines. Importantly, cell line and animal experiments both confirmed that E2F6 promotes ovarian cancer stemness, whereas E2F6 or EZH2 depletion derepressed miR‐193a, which opposes cancer stemness, by alleviating DNA methylation and repressive chromatin. Finally, 118 ovarian cancer patients with miR‐193a promoter hypermethylation had poorer survival than those without hypermethylation. These results suggest that an estrogen‐mediated E2F6 ceRNA network epigenetically and competitively inhibits microRNA‐193a activity, promoting ovarian cancer stemness and tumorigenesis.

[Personal dose monitoring of radiation workers in medical institutions at the municipal level and below in a city from 2011 to 2014]

Objective: To determine the personal dose level of radiation workers in medical institutions at the municipal level and below in a city, and to provide a scientific support for strengthening the radiation protection in the city's medical institutions. Methods: Information of the successful applicants for the "Radiation Worker Permit" from 174 medical institutions at the municipal level and below was collected from October 1, 2011 to December 31, 2014. The annual effective dose was calculated based on the personal dose monitoring report, and indicators including sex, permit application time, hospital level, type of occupational radiation, length of radiation work, blood test, and micronucleated lymphocyte rate were analyzed. Results: Of the 1 143 radiation worker permit applications submitted by medical institutions the municipal level and below in this city from 2011 to 2014, 1 123 provided at least one personal dose monitoring report. The annual effective dose of the radiation workers was 0-4.76 mSv (mean 0.31±0.40 mSv) , and the collective annual effective dose was 351.96 mSv. The annual effective dose was significantly different between radiation workers with different times of permit application, hospital levels, and types of occupational radiation (P<0.05) . Interventional radiology workers had the highest annual effective dose (0.63 mSv) , and annual effective dose was significantly different between interventional radiology workers with different lengths of radiation work (H=10.812, P<0.05) . Conclusion: The personal radiation dose of radiation workers in medical institutions at the municipal level and below in this city is maintained at a relatively low level, suggesting that the occupational environment is relatively safe for these workers. However, more focus should be placed on clinical interventional radiology workers.

GATA3 as a master regulator and therapeutic target in ovarian high-grade serous carcinoma stem cells

Ovarian high-grade serous carcinoma (HGSC) is the most lethal gynecological malignancy. Prevailing evidences suggest that drug resistance and recurrence of ovarian HGSC are caused by the presence of cancer stem cells. Therefore, targeting cancer stems is appealing, however, all attempts to date, have failed. To circumvent this limit, we analyzed differential transcriptomes at early differentiation of ovarian HGSC stem cells and identified the developmental transcription factor GATA3 as highly expressed in stem, compared to progenitor cells. GATA3 expression associates with poor prognosis of ovarian HGSC patients, and was found to recruit the histone H3, lysine 27 (H3K27) demethylase, UTX, activate stemness markers, and promote stem-like phenotypes in ovarian HGSC cell lines. Targeting UTX by its inhibitor, GSKJ4, impeded GATA3-driven stemness phenotypes, and enhanced apoptosis of GATA3-expressing cancer cells. Combinations of gemcitabine or paclitaxel with GSKJ4, resulted in a synergistic cytotoxic effect. Our findings provide evidence for a new role for GATA3 in ovarian HGSC stemness, and demonstrate that GATA3 may serve as a biomarker for precision epigenetic therapy in the future.

Epigenetic loss of heparan sulfate 3-O-sulfation sensitizes ovarian carcinoma to oncogenic signals and predicts prognosis

Precision medicine requires markers for therapeutic guidance. The purpose of this study was to determine whether epithelial ovarian cancer (EOC) epigenetics can lead to the identification of biomarkers for precision medicine. Through integrative methylomics, we discovered and validated the epigenetic signature of NEFH and HS3ST2 as an independent prognostic factor for type II EOC in our dataset (n = 84), and two independent methylomics datasets (total n = 467). Integrated transcriptomics dataset (n = 1147) and tissue microarrays (n = 54) of HS3ST2 also related to high-methylation statuses and the EOC prognosis. Mechanistic explorations of HS3ST2 have assessed responses to oncogenic stimulations such as IL-6, EGF, and FGF2 in cancer cells. The combination of HS3ST2 and various oncogenic ligands also confers the worse outcome. 3-O-sulfation of heparan sulfate by HS3ST2 makes ovarian cancer cells intrinsically sensitive to oncogenic signals, which sheds new light on the application of HS3ST2 as a companion diagnostic for targeted therapy using kinase inhibitors or therapeutic antibodies.

Residue and distribution of triforine in different cultivars and fruit periods of watermelon under field conditions

The dissipation of triforine in the immature and mature fruit periods was investigated under field conditions. Residue levels of triforine in watermelon were determined by gas chromatography with an electron capture detector (GC-ECD). The decline curves of triforine residues in the watermelon corresponded with first-order kinetics. The half-lives of triforine in Dark Belle and Shiny Boy were 2.10-2.57 days and 2.31-2.67 days respectively. Meanwhile, the half-lives of triforine in the immature and mature fruit periods were 1.69-2.04 days and 2.89-3.85 days, respectively. In the terminal residue experiment, the terminal residues of triforine in the watermelon flesh and peel were below 0.01 mg/kg to 0.05 mg/kg and 0.03 mg/kg to 0.36 mg/kg, respectively. The dissipation rates of triforine varied in different cultivars of watermelon, and even in the same cultivar, the half-lives of triforine significantly varied in the different fruit periods. Although triforine is a fungicide within the suction, the terminal residues in the peel and flesh were very significant.

Correction to: Prof. Huan-Yong Chen: a leading botanist and taxonomist, one of the pioneers and founders of modern plant taxonomy in China

In the original publication, there are some incorrect information.

Abstract 74: E2F6-mediated ceRNA and epigenetic silencing of miR193a lead to cancer stemness and anticancer immunity in ovarian cancer

Ovarian cancer is one of the most lethal cancers in the female reproductive system. Previous study suggested that long term treatment of estrogen such as hormonal replacement therapy (HRT) may increase the risk of ovarian cancer, however the role of estrogen in ovarian carcinogenesis is still controversial. To decipher this complicated process, we generated a mathematical model and found that estrogen-mediated up-regulation of E2F6 could upregulate the ovarian cancer stem/initiating marker, c-kit by two means one through epigenetic silencing of their co-targeted miR193a by binding of E2F6 which subsequently recruit EZH2 to miR-193a promoter; and second, by competing endogenous (ceRNA) mechanism. To confirm this model, treatment of E2 or environmental hormone, BPA resulted in upregulation of both E2F6 and c-kit but down-regulation of miR-193a in immortalized ovarian surface epithelial cells. Further bisulfite pyrosequencing, ChIP-qPCR and epigenetic treatment found that miR193a was epigenetically silenced by DNA methylation and H3K27me3 in CP70 but not HeyC2 ovarian cancer cells. Overexpression of miR193a inhibited tumor growth in vitro and in vivo. Depletion of EZH2 or E2F6 in CP70 restored miR-193a expression and decreased the number of “ovo” spheroid by reversing the repressive chromatin status of miR-193a promoter. To further explore the biological significance of this E2F6 ceRNA network, integrative RNA-Seq and computational analysis found that PBX1, a miR-193a target and transcriptional activator of the immunosuppressive cytokine IL-10, was down-regulated in E2F6 and EZH2 knockdown CP70 cells. Overexpression of E2F6 3'UTR containing miR-193a MRE but not MRE mutant increased the expression of PBX1 and IL10 in ovarian cancer cells. Importantly, co-culture of conditional media from E2F6 3'UTR overexpressing CP70 cells inhibited the differentiation of THP-1 monocytes into dendritic cell and the T-cell activating function of this THP-1 derived DC. This phenomenon can be rescued by incubation of anti-IL-10 antibody or pretreatment of CP70 cells with EZH2 inhibitor. Finally, clinical studies demonstrated that patients with higher promoter methylation of miR193a were associated with poor survival. Serum IL10 level was found to be higher in high staged ovarian cancer patients and patients with higher E2F6 mRNA level. Additional analysis from TCGA ovarian cancer expression microarray dataset demonstrated that ovarian cancer patients with low expression of EZH2, showed a positive correlation between E2F6, c-KIT and PBX1 resembling the ceRNA phenomenon between these mRNAs. Taken together, our results showed that estrogen-mediated E2F6 ceRNA network can regulate cancer stemness and anti-tumor immunity of DC through epigenetic silencing of miR-193a. Anti-estrogen therapy together with the EZH2 inhibitor may be a novel strategy against this deadly cancer.

Citation Format: Frank Hsueh-Che Cheng, Hon-Yi Lin, Yin-Chen Chen, Tzy-Wei Hwang, Rui-Lan Huang, Chia-Bin Chang, Ru-Inn Lin, Ching-Wen Lin, Gary C.W. Chen, Jora M. J. Lin, Yu-Ming Chuang, Jian-Liang Chou, Chin Li, Alfred S.L. Cheng, Hung-Cheng Lai, Shu-Fen Wu, Je-Chiang Tsai, Michael W.Y. Chan. E2F6-mediated ceRNA and epigenetic silencing of miR193a lead to cancer stemness and anticancer immunity in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 74.

Distinct methylation profile of mucinous ovarian carcinoma reveals susceptibility to proteasome inhibitors

Mucinous type of epithelial ovarian cancer (MuOC) is a unique subtype with a poor survival outcome in recurrent and advanced stages. The role of type-specific epigenomics and its clinical significance remains uncertain. We analyzed the methylomic profiles of 6 benign mucinous adenomas, 24 MuOCs, 103 serous type of epithelial ovarian cancers (SeOCs) and 337 nonepithelial ovarian cancers. MuOC and SeOC exhibited distinct DNA methylation profiles comprising 101 genes, 81 of which exhibited low methylation in MuOC and were associated with the response to glucocorticoid, ATP hydrolysis-coupled proton transport, proteolysis involved in the cellular protein catabolic process and ion transmembrane transport. Hierarchical clustering analysis showed that the profiles of MuOC were similar to colorectal adenocarcinoma and stomach adenocarcinoma. Genetic interaction network analysis of differentially methylated genes in MuOC showed a dominant network module is the proteasome subunit beta (PSMB) family. Combined functional module and methylation analysis identified PSMB8 as a candidate marker for MuOC. Immunohistochemical staining of PSMB8 used to validate in 94 samples of ovarian tumors (mucinous adenoma, MuOC or SeOC) and 62 samples of gastrointestinal cancer. PSMB8 was commonly expressed in MuOC and gastrointestinal cancer samples, predominantly as strong cytoplasmic and occasionally weak nuclei staining, but was not expressed in SeOC samples. Carfilzomib, a second-generation proteasome inhibitor, suppressed MuOC cell growth in vitro. This study unveiled a mucinous-type-specific methylation profile and suggests the potential use of a proteasome inhibitor to treat MuOC.

Dissipation and residue of clothianidin in granules and pesticide fertilizers used in cabbage and soil under field conditions

The single application of 0.5 % clothianidin granules, a novel formulation, was used to control pests in vegetables under a high dose. In this article, residues of clothianidin in cabbage and soil samples under field conditions from Guangzhou, Nanning, and Qianjiang were determined by HPLC. The terminal residues of clothianidin in cabbage were less than the limit of detection (<LOD) at pre-harvest intervals of 30 days, and these values were lower than the maximum residue limit of 0.2 mg kg^-1 in cabbage set by the Codex Alimentarius Commission. To test on the influence of the pesticide fertilizers' effect on clothianidin residual, clothianidin granules and fertilizers of chicken manure, urea, and organic fertilizer were mixed into different pesticide fertilizers through their normal field using dosage and evaluate residual influence of clothianidin in different formula. After analysis of variance of the effect factors, the effect of different pesticide types on half-life was not significant, but the effect of sample types was significant. Clothianidin granules and pesticide fertilizers could be safely applied in cabbage under a single high-dose administration.

Loss of discoidin domain receptor 1 (DDR1) via CpG methylation during EMT in epithelial ovarian cancer

Epithelial ovarian cancer (EOC) can be stratified according to the stages of epithelial-mesenchymal transition (EMT). Here, we aim to identify tyrosine kinases (TKs) in EOC that correlate with the EMT subtypes. By gene expression microarray, we analyzed the expression levels of tyrosine kinases in EOC cell lines in correlation with EMT. Among the candidate TKs identified, DDR1 was expressed mainly in EOC cells with an Epithelial phenotype. Its expression was validated by qPCR, ELISA and western blotting. Using Infinium HumanMethylation27K BeadChip array and pyrosequencing, we further analyzed the CpG methylation levels at the DDR1 promoter in EOC cells and found that the CpG methylation levels of DDR1 promoter correlated negatively with the expression of DDR1 along the EMT spectrum. Therefore, EMT stratification could be a potential biomarker to predict patient response to DDR1-targeting drugs.

Idiopathic Low Ovarian Reserve Is Associated with More Frequent Positive Thyroid Peroxidase Antibodies

BACKGROUND

While screening of thyroid peroxidase antibody (TPOAb) has been recommended in women with primary ovarian insufficiency, the relationship between thyroid autoimmunity (TAI) and ovarian reserve remains undetermined. Because the TAI prevalence was reported to be different between different ethnic/racial groups, this study aimed to investigate the TAI prevalence in Chinese women with variable ovarian reserve.

METHODS

This is a cross-sectional study conducted in a university infertility clinic between October 2013 and March 2016. Among patients at their first entry to the infertility clinic, a total of 1044 patients with available results of anti-Müllerian hormone (AMH), thyrotropin (TSH), TPOAb, and thyroglobulin antibody (TgAb) were enrolled. The TSH levels and the prevalence of positive TPOAb and positive TgAb were compared between patients with low, normal, and high ovarian reserve categorized with age-specific AMH levels.

RESULTS

For the whole study population, the TSH levels, TPOAb positivity, and TgAb positivity were comparable between patients with variable ovarian reserve. However, after patients with known causes compromising ovarian reserve (iatrogenic or genetic) were excluded, only TPOAb positivity became significantly different between patients with low (22.7%), normal (14.0%), and high ovarian reserve (10.3%; p = 0.012). The TPOAb levels were not significantly correlated to AMH levels (Spearman's ρ = -0.027; p = 0.413). For the infertile subgroup, TPOAb positivity was significantly associated with idiopathic low ovarian reserve in unexplained infertility (low ovarian reserve: 28.6%; normal: 15.7%; high: 9.5%; p = 0.020).

CONCLUSIONS

Idiopathic low ovarian reserve was associated with more frequent positive TPOAb rather than thyroid function or TgAb positivity in Chinese women.

Pyruvate kinase M2 is a poor prognostic marker of and a therapeutic target in ovarian cancer

Pyruvate kinase M2 (PKM2) regulates glycolysis and oxidative phosphorylation; however, the role of PKM2 in ovarian cancer remains largely unknown. We investigated whether ovarian cancer metabolism could provide insight into the development of therapeutic strategies. We performed immunohistochemical staining for PKM2 on a tissue microarray for multivariate analysis. It revealed that patients exhibiting higher PKM2 expression were significantly associated with malignancy groups (p < 0.001) and pathogenesis models (p < 0.001), had poor progression-free survival rates (p = 0.01) as compared with patients exhibiting lower PKM2 levels, and yielded a hazard ratio of death of 2.02 (95% confidence interval: 0.70–5.85). In cell lines, PKM2 inhibitor significantly inhibited the glycolytic rate according to cellular glucose consumption (p < 0.001). We also utilized Seahorse assays to assess metabolism-related cell-specific factors and the impact of PKM2 inhibitors. Energy shifts as per Seahorse analysis showed attenuation of the extracellular acidification rate (p < 0.05) and no significant difference in oxygen-consumption rate in SKOV3 cells. Treatment with PKM2 inhibitor suppressed ovarian cancer growth and cell migration in vitro and inhibited tumor growth without significant toxicity in a xenograft study. PKM2 inhibition disturbed Warburg effects and inhibited ovarian cancer cell growth. Targeting PKM2 may constitute a promising therapy for patients with ovarian cancer, and clinical trials involving shikonin are warranted.

An epigenetic signature of adhesion molecules predicts poor prognosis of ovarian cancer patients

DNA methylation is a promising biomarker for cancer. The epigenetic effects of cell adhesion molecules may affect the therapeutic outcome and the present study examined their effects on survival in ovarian cancer. We integrated methylomics and genomics datasets in The Cancer Genome Atlas (n = 391) and identified 106 highly methylated adhesion-related genes in ovarian cancer tissues. Univariate analysis revealed the methylation status of eight genes related to progression-free survival. In multivariate Cox regression analysis, four highly methylated genes (CD97, CTNNA1, DLC1, HAPLN2) and three genes (LAMA4, LPP, MFAP4) with low methylation were significantly associated with poor progression-free survival. Low methylation of VTN was an independent poor prognostic factor for overall survival after adjustment for age and stage. Patients who carried any two of CTNNA1, DLC1 or MFAP4 were significantly associated with poor progression-free survival (hazard ratio: 1.59; 95% confidence interval: 1.23, 2.05). This prognostic methylation signature was validated in a methylomics dataset generated in our lab (n = 37, hazard ratio: 16.64; 95% confidence interval: 2.68, 103.14) and in another from the Australian Ovarian Cancer Study (n = 91, hazard ratio: 2.43; 95% confidence interval: 1.11, 5.36). Epigenetics of cell adhesion molecules is related to ovarian cancer prognosis. A more comprehensive methylomics of cell adhesion molecules is needed and may advance personalized treatment with adhesion molecule-related drugs.

Methylomics of nitroxidative stress on precancerous cells reveals DNA methylation alteration at the transition from in situ to invasive cervical cancer

Epigenetic dysregulation is important in cervical cancer development, but the underlying mechanism is largely unknown. Increasing evidence indicates that DNA methylation is sensitive to changes in microenvironmental factors, such as nitric oxide (NO) in the chronic inflammatory cervix. However, the epigenomic effects of NO in cancer have not been investigated. In this study, we explored the methylomic effects of nitroxidative stress in HPV-immortalized precancerous cells. Chronic NO exposure promoted the acquisition of malignant phenotypes such as cell growth, migration, invasion, and anchorage-independent growth. Epigenetic analysis confirmed hypermethylation of PTPRR. Whole-genome methylation analysis showed BOLA2B, FGF8, HSPA6, LYPD2, and SHE were hypermethylated in cells. The hypermethylation BOLA2B, FGF8, HSPA6, and SHE was confirmed in cervical scrapings from invasive cancer, but not in CIN3/CIS, CIN2 and CIN1 (p=0.019, 0.023, 0.023 and 0.027 respectively), suggesting the role in the transition from in situ to invasive process. Our results reveal that nitroxidative stress causes epigenetic changes in HPV-infected cells. Investigation of these methylation changes in persistent HPV infection may help identify new biomarkers of DNA methylation for cervical cancer screening, especially for precancerous lesions.

Preclinical evaluation of a nanoformulated antihelminthic, niclosamide, in ovarian cancer

Ovarian cancer treatment remains a challenge and targeting cancer stem cells presents a promising strategy. Niclosamide is an “old” antihelminthic drug that uncouples mitochondria of intestinal parasites. Although recent studies demonstrated that niclosamide could be a potential anticancer agent, its poor water solubility needs to be overcome before further preclinical and clinical investigations can be conducted. Therefore, we evaluated a novel nanosuspension of niclosamide (nano-NI) for its effect against ovarian cancer. Nano-NI effectively inhibited the growth of ovarian cancer cells in which it induced a metabolic shift to glycolysis at a concentration of less than 3 μM in vitro and suppressed tumor growth without obvious toxicity at an oral dose of 100 mg/kg in vivo. In a pharmacokinetic study after oral administration, nano-NI showed rapid absorption (reaching the maximum plasma concentration within 5 min) and improved the bioavailability (the estimated bioavailability for oral nano-NI was 25%). In conclusion, nano-NI has the potential to be a new treatment modality for ovarian cancer and, therefore, further clinical trials are warranted.

The cytokine-cosmc signaling axis upregulates the tumor-associated carbohydrate antigen Tn

Tn antigen (GalNAc-α-O-Ser/Thr), a mucin-type O-linked glycan, is a well-established cell surface marker for tumors and its elevated levels have been correlated with cancer progression and prognosis. There are also reports that Tn is elevated in inflammatory tissues. However, the molecular mechanism for its elevated levels in cancer and inflammation is unclear. In the current studies, we have explored the possibility that cytokines may be one of the common regulatory molecules for elevated Tn levels in both cancer and inflammation. We showed that the Tn level is elevated by the conditioned media of HrasG12V-transformed-BEAS-2B cells. Similarly, the conditioned media obtained from LPS-stimulated monocytes also elevated Tn levels in primary human gingival fibroblasts, suggesting the involvement of cytokines and/or other soluble factors. Indeed, purified inflammatory cytokines such as TNF-α and IL-6 up-regulated Tn levels in gingival fibroblasts. Furthermore, TNF-α was shown to down-regulate the COSMC gene as evidenced by reduced levels of the COSMC mRNA and protein, as well as hypermethylation of the CpG islands of the COSMC gene promoter. Since Cosmc, a chaperone for T-synthase, is known to negatively regulate Tn levels, our results suggest elevated Tn levels in cancer and inflammation may be commonly regulated by the cytokine-Cosmc signaling axis.

Triage of high-risk human papillomavirus-positive women by methylated POU4F3

BACKGROUND

Insufficient specificity of the high-risk human papillomavirus (hrHPV) assay in primary cervical cancer screening results in unnecessary referral. Additional assays to triage hrHPV-positive women are needed to improve molecular cervical cancer screening. DNA methylation is a promising biomarker in cervical cancer. We evaluated the clinical performance of potentially methylated genes as a triage assay for hrHPV-positive women.

RESULTS

We conducted a retrospective hospital-based case-control study in Taiwan. Cervical scrapings were collected before colposcopy for hrHPV testing and quantitative methylation-specific PCR (QMSP) of 16 genes. Five genes, POU4F3, HS3ST2, AJAP1, PAX1, and SOX1, were prioritized for the clinical performance to triage hrHPV-positive women. Two hundred cervical scrapings were randomly classified into a training set (n = 111) and testing set (n = 89). All samples were tested for hrHPV using a Hybrid Capture II (HCII) assay. HrHPV-positive women were subjected to DNA methylation analysis by QMSP. In the training set, the receiver operating characteristic (ROC) curves defined the optimal methylation index (M-index) cutoff values for discriminating CIN3(+) from CIN1/normal, which then were applied to the testing set. Among the five genes, POU4F3 revealed the highest area under the ROC curve (AUC) (0.86; 95 % CI, 0.78-0.95) in detecting CIN3(+). In the testing set, POU4F3 revealed the best clinical performance in triage of hrHPV-positive women with a sensitivity of 74 % and specificity of 89 % for detecting CIN3(+).

CONCLUSIONS

POU4F3 methylation analysis is a potential molecular tool for triage in detecting CIN3(+) in hrHPV-positive women. The combined use of broad-spectrum HPV assay and POU4F3 methylation analysis as a new generation of molecular cervical cancer screening warrants further population-based study.

Abstract 1128: TET1-mediated epigenetic reprogramming switches metabolism and promotes malignant phenotypes of ovarian cancer

Epigenetic dysregulation is one of the mechanisms involved in ovarian cancer carcinogenesis. Recently identified a new epigenetic modulator ten-eleven translocation protein 1 (TET1), a DNA dioxygenase which is believed in DNA demethylation through a 5-methylcytosine to 5-hydroxymethylcytosine (5hmC) conversion, plays an important role in regulating self-renewal and specification in embryonic stem cells. In addition, it works as a tumor suppressor gene by inhibition of cell invasion, migration and tumor growth in breast and prostate cancer. However, the role of TET1 in ovarian cancer remains unknown. Thus we examed the expression level of TET1 in ovarian cancer tissues. We found that TET1 expression level correlated with cancer staging (p = 0.03) in 88 ovarian cancer from our biobank and poor survival (p = 0.012) in TCGA database. High expression of TET1 was observed in advanced stage, high-grade primary tumor specimens in comparison with normal ovarian surface epithelium (OSE) brushings (p = 0.0005) by NCBI database (GSE18520). These results suggested that TET1 may play some roles in ovarian cancer development, which is different from those previously published in other cancers. To study the function of TET1 in ovarian cancer, we generated TET1 over-expressing and knockdown cell lines model, the expression level and enzymatic activities of TET1 were confirmed by real time PCR, western and 5hmC stain. Here we found that TET1 increases the abilities of cell migration, anchorage-independent growth and promotes tumor growth. In addition, TET1 actives cancer stem markers and enhances the abilities of spheroid formation. Ovarian cancer stem cells (OCSCs) from cell line express high level of TET1 while the differentiated progenies suppress TET1 expression. Moreover, seven of eight patient-derived OCSCs revealed high expressing of TET1 in comparison with its parental cancer cells by quantitative PCR. To further examine the TET1 regulation network, we combined the expression array and MethCap-seq to analyze the epigomic changes. We found that a cluster of target genes which were up-regulated through DNA demethylation were enzymes responsible for oxidative phosphorylation. We investigated metabolic status by Extracellular Flux Analyzer (seahourse) on the TET1-overexpressing cells. Compared with control cells, TET1-overexpressing cells revealed 1.7 fold (p = 0.011) increase of oxygen consumption rate (OCR); while the extracellular acidification rate (ECAR) showed no difference (p = 0.856). This bioenergetic metabolism shift may be due to demethylation of subunits of mitochondria complexs. Taken together, TET1 reprograms the epigenome, shifts the metabolism, increases the malignant phenotypes and confers a poor prognosis of ovarian cancer. Targeting mitochondria on TET1-expressing ovarian cancer patients may provide a new way of personalized therapy.

Citation Format: Lin-yu Chen, Rui-Lan Huang, Pearlly S. Yan, Tien-Shuo Huang, Yu-Ping Liao, Jian-Liang Chou, Jora M.J. Lin, Tai-Kuang Chao, Michael W.Y. Chan, Wun-Shaing Wayne Chang, Hung-Cheng Lai. TET1-mediated epigenetic reprogramming switches metabolism and promotes malignant phenotypes of ovarian cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1128. doi:10.1158/1538-7445.AM2015-1128

Serum cytokeratin-19 fragment (Cyfra 21-1) is a prognostic indicator for epithelial ovarian cancer

OBJECTIVES

Cytokeratin 19 is significant for indicating cancer cells, and Cyfra 21-1 is a fragment of cytokeratin 19. This retrospective study was designed to define the prognostic value of serum Cyfra 21-1 in epithelial ovarian cancers (EOC).

MATERIALS AND METHODS

Serum Cyfra 21-1 concentration was obtained from 42 patients with EOC prior to treatment. Various prognostic aspects were examined using univariable and multivariable analyses. The standard serum marker cancer antigen 125 was measured simultaneously and compared in this analysis.

RESULTS

Serum levels of both Cyfra 21-1 and cancer antigen 125 were associated with positive retroperitoneal lymph nodes and platinum resistance; higher levels of Cyfra 21-1 (3.0 ng/mL as the cut-off) were associated with shorter disease-free survival (16 months vs. 28 months, p = 0.001) and overall survival (29 months vs. 41 months, p = 0.007) than lower levels. Further univariable analysis showed that Cyfra 21-1, poor differentiation, and retroperitoneal lymph node metastasis were related to platinum resistance and mortality. Multivariable analysis indicated retroperitoneal lymph node metastasis and serum Cyfra 21-1 were independent risk factors for both disease-free survival and overall survival.

CONCLUSION

The pretreatment level of serum Cyfra 21-1 had remarkable prognostic significance for EOC, indicating poor survival when it was elevated above 3.0 ng/mL.

Genome-wide DNA methylation analysis reveals estrogen-mediated epigenetic repression of metallothionein-1 gene cluster in breast cancer

Background

Recent genome-wide analysis has shown that DNA methylation spans long stretches of chromosome regions consisting of clusters of contiguous CpG islands or gene families. Hypermethylation of various gene clusters has been reported in many types of cancer. In this study, we conducted methyl-binding domain capture (MBDCap) sequencing (MBD-seq) analysis on a breast cancer cohort consisting of 77 patients and 10 normal controls, as well as a panel of 38 breast cancer cell lines.

Results

Bioinformatics analysis determined seven gene clusters with a significant difference in overall survival (OS) and further revealed a distinct feature that the conservation of a large gene cluster (approximately 70 kb) metallothionein-1 (MT1) among 45 species is much lower than the average of all RefSeq genes. Furthermore, we found that DNA methylation is an important epigenetic regulator contributing to gene repression of MT1 gene cluster in both ERα positive (ERα+) and ERα negative (ERα−) breast tumors. In silico analysis revealed much lower gene expression of this cluster in The Cancer Genome Atlas (TCGA) cohort for ERα + tumors. To further investigate the role of estrogen, we conducted 17β-estradiol (E2) and demethylating agent 5-aza-2′-deoxycytidine (DAC) treatment in various breast cancer cell types. Cell proliferation and invasion assays suggested MT1F and MT1M may play an anti-oncogenic role in breast cancer.

Conclusions

Our data suggests that DNA methylation in large contiguous gene clusters can be potential prognostic markers of breast cancer. Further investigation of these clusters revealed that estrogen mediates epigenetic repression of MT1 cluster in ERα + breast cancer cell lines. In all, our studies identify thousands of breast tumor hypermethylated regions for the first time, in particular, discovering seven large contiguous hypermethylated gene clusters.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-015-0045-9) contains supplementary material, which is available to authorized users.

Molecular characterization and expression analysis of purple acid phosphatase gene from pearl oyster Pinctada martensii

Purple acid phosphatases (PAPs), also known as type 5 acid phosphatases, are widely present in animals, plants, and fungi. In mammal, PAP was reported to participate in immune defense and bone resorption. In this study, the characteristics and potential functions of a PAP gene from pearl oyster Pinctada martensii (pm-PAP) were examined. The Pm-PAP cDNA was found to be 2777 base pairs, containing a 1581-base pair open reading fragment encoding for 526 amino acids with an estimated molecular mass of 60.1 kDa and theoretical isoelectric point of 5.82. One signal peptide and five conserved motifs [GDXX/GDXXY/GNH(D/E)/XXXH/(A/G)HXH] were present in the entire sequence. Tissue expression profile analysis showed that pm-PAP mRNA was constitutively expressed in all tissues studied with abundant mRNA found in mollusk defense system, including hepatopancreas, gill, and hemocytes. After lipopolysaccharide stimulation, the expression of pm-PAP mRNA in hemocytes was dramatically upregulated at 2 h and achieved the highest level at 36 h. Additionally, pm-PAP mRNA expression was significantly increased and achieved the highest level at 2 days after the surgical implantation during pearl production. These results suggest that pm-PAP is a constitutive and inducible protein that may be involved in the immune defense of pearl oyster.

Pyrrolidine dithiocarbamate restores gastric damages and suppressive autophagy induced by hydrogen peroxide

It is well known that gastric barrier is very important for protecting host from various insults. Simultaneously, autophagy serving as a prominent cytoprotective and survival pathway under oxidative stress conditions is being increasingly recognized. Thus, this study was conducted for investigating the effect of pyrrolidine dithiocarbamate (PDTC) on gastric barrier function and autophagy under oxidative stress induced by intragastric administration of hydrogen peroxide (H2O2). The gastric tight junction proteins [zonula occludens-1 (ZO1), occludin, and claudin1], autophagic proteins [microtubule-associated protein light chain 3I(LC3I), LC3II, and beclin1], and nuclear factor kappa B (NF-κB) signaling pathway (p65 and IκB kinase α/β) were determined by Western blot. The results showed that H2O2 exposure disturbed gastric barrier function with decreased expression of ZO1, occludin, and claudin1, and reduced gastric autophagy with decreased conversion of LC3I into LC3II in mice. However, treatment with PDTC restored these adverse effects evidenced by increased expression of ZO1 and claudin1 and increased conversion of LC3I into LC3II. Meanwhile, H2O2 exposure decreased normal human gastric epithelial mucosa cell line (GES-1) viability in a concentration-dependent way. However, after being exposed to H2O2, GES-1 exhibited autophagic response which was inconsistent with our in vivo results in mice, while PDTC failed to decrease autophagy in GES-1 induced by H2O2. Simultaneously, the beneficial effect of PDTC on gastric damage and autophagy in mice might be independent of inhibition of NF-κB. In conclusion, PDTC treatment restores gastric damages and reduced autophagy induced by H2O2. Therefore, PDTC may serve as a potential adjuvant therapy for gastric damages.

Hypermethylation of the TGF-β target, ABCA1 is associated with poor prognosis in ovarian cancer patients

Background

The dysregulation of transforming growth factor-β (TGF-β) signaling plays a crucial role in ovarian carcinogenesis and in maintaining cancer stem cell properties. Classified as a member of the ATP-binding cassette (ABC) family, ABCA1 was previously identified by methylated DNA immunoprecipitation microarray (mDIP-Chip) to be methylated in ovarian cancer cell lines, A2780 and CP70. By microarray, it was also found to be upregulated in immortalized ovarian surface epithelial (IOSE) cells following TGF-β treatment. Thus, we hypothesized that ABCA1 may be involved in ovarian cancer and its initiation.

Results

We first compared the expression level of ABCA1 in IOSE cells and a panel of ovarian cancer cell lines and found that ABCA1 was expressed in HeyC2, SKOV3, MCP3, and MCP2 ovarian cancer cell lines but downregulated in A2780 and CP70 ovarian cancer cell lines. The reduced expression of ABCA1 in A2780 and CP70 cells was associated with promoter hypermethylation, as demonstrated by bisulfite pyro-sequencing. We also found that knockdown of ABCA1 increased the cholesterol level and promoted cell growth in vitro and in vivo. Further analysis of ABCA1 methylation in 76 ovarian cancer patient samples demonstrated that patients with higher ABCA1 methylation are associated with high stage (P = 0.0131) and grade (P = 0.0137). Kaplan-Meier analysis also found that patients with higher levels of methylation of ABCA1 have shorter overall survival (P = 0.019). Furthermore, tissue microarray using 55 ovarian cancer patient samples revealed that patients with a lower level of ABCA1 expression are associated with shorter progress-free survival (P = 0.038).

Conclusions

ABCA1 may be a tumor suppressor and is hypermethylated in a subset of ovarian cancer patients. Hypermethylation of ABCA1 is associated with poor prognosis in these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s13148-014-0036-2) contains supplementary material, which is available to authorized users.

Global methylation silencing of clustered proto-cadherin genes in cervical cancer: serving as diagnostic markers comparable to HPV

Epigenetic remodeling of cell adhesion genes is a common phenomenon in cancer invasion. This study aims to investigate global methylation of cell adhesion genes in cervical carcinogenesis and to apply them in early detection of cancer from cervical scraping. Genome-wide methylation array was performed on an investigation cohort, including 16 cervical intraepithelial neoplasia 3 (CIN3) and 20 cervical cancers (CA) versus 12 each of normal, inflammation and CIN1 as controls. Twelve members of clustered proto-cadherin (PCDH) genes were collectively methylated and silenced, which were validated in cancer cells of the cervix, endometrium, liver, head and neck, breast, and lung. In an independent cohort including 107 controls, 66 CIN1, 85 CIN2/3, and 38 CA, methylated PCDHA4 and PCDHA13 were detected in 2.8%, 24.2%, 52.9%, and 84.2% (P < 10⁻²⁵), and 2.8%, 24.2%, 50.6%, and 94.7% (P < 10⁻²⁹), respectively. In diagnosis of CIN2 or more severe lesion of the cervix, a combination test of methylated PCDHA4 or PCDHA13 from cervical scraping had a sensitivity, specificity, positive predictive value, and negative predictive value of 74.8%, 80.3%, 73%, and 81.8%, respectively. Testing of this combination from cervical scraping is equally sensitive but more specific than human papillomavirus (HPV) test in diagnosis of CIN2 or more severe lesions. The study disclosed a collective methylation of PCDH genes in cancer of cervix and other sites. At least two of them can be promising diagnostic markers for cervical cancer noninferior to HPV.

Ovarian cancer stem-like cells show induced translineage-differentiation capacity and are suppressed by alkaline phosphatase inhibitor

Spheroid formation is one property of stem cells—such as embryo-derived or neural stem cells—that has been used for the enrichment of cancer stem-like cells (CSLCs). However, it is unclear whether CSLC-derived spheroids are heterogeneous or whether they share common embryonic stemness properties. Understanding these features might lead to novel therapeutic approaches. Ovarian carcinoma is a deadly disease of women. We identified two types of spheroids (SR1 and SR2) from ovarian cancer cell lines and patients' specimens according to their morphology. Both types expressed stemness markers and could self-renew and initiate tumors when a low number of cells were used. Only SR1 could differentiate into multiple-lineage cell types under specific induction conditions. SR1 spheroids could differentiate to SR2 spheroids through epithelial–mesenchymal transition. Alkaline phosphatase (ALP) was highly expressed in SR1 spheroids, decreased in SR2 spheroids, and was absent in differentiated progenies in accordance with the loss of stemness properties. We verified that ALP can be a marker for ovarian CSLCs, and patients with greater ALP expression is related to advanced clinical stages and have a higher risk of recurrence and lower survival rate. The ALP inhibitor, levamisole, disrupted the self-renewal of ovarian CSLCs in vitro and tumor growth in vivo. In summary, this research provides a plastic ovarian cancer stem cell model and a new understanding of the cross-link between stem cells and cancers. This results show that ovarian CSLCs can be suppressed by levamisole. Our findings demonstrated that some ovarian CSLCs may restore ALP activity, and this suggests that inhibition of ALP activity may present a new opportunity for treatment of ovarian cancer.

Abstract 1376: EpCAM-mediated hypomethylation of BMP and cell adhesion genes is associated with advanced endometrial cancer

Endometrial cancer (EC) is the most common gynecologic malignancy, with approximately 20% of EC patients developing advanced stage recurrent tumors and frequent metastasis. Our goal was to investigate whether DNA methylation signatures associated with low promoter methylation (hypomethylation) and specific oncogenic signaling delineate predictive markers of endometrial cancer recurrence. Global screening by Methyl-CpG-capture sequencing revealed aberrant DNA methylation in our endometrial cancer cohort and identified a subset of bone morphogenetic protein family (BMP1, 2, 3, 4, and 7) exhibiting frequent hypomethylation in primary tumors with subsequent recurrence compared with non-recurrent tumors. This epigenetic signature correlated with poor survival and was validated in The Cancer Genome Atlas endometrial cancer cohort. Our functional studies also implicated epidermal growth factor receptor (EGFR) pathway in the transcriptional activation of these BMPs and inducing epithelial-mesenchymal transition (EMT). In addition to AKT and MAPK, the epithelial cell adhesion molecule (EpCAM) mediated these actions by EGFR. EpCAM involvement in cancer progression includes nuclear co-translocation of its intracellular domain EpICD with Lef-1 complexes and targeting oncogene promoter activation. In this study, EGF stimulated EpICD-Lef-1 binding on BMP genes accompanied with histone active modification marks. EpICD knockdown resulted in increased repressive histone marks and DNA methylation at these loci, suggesting that EpICD occupancy is involved in their epigenetic modification to an open transcriptional conformation. Knockdown of candidate BMPs led to decreased endometrial cancer cell invasiveness, implicating them in aggressive growth. Extending our studies, we performed ChIP-Seq analysis to identify global regulation by the EpICD-Lef-1 complexes in endometrial cancer. Interestingly, under basal levels only about 28% of loci targeted by either EpICD or Lef-1 were commonly targeted by EpICD-Lef-1, with common targets increasing to about 50% in 24 hrs and 73% in 48 hrs post EGF treatment. This indicates that EGFR signaling stimulates a time-course dependent enrichment of EpICD-Lef-1 convergence on target loci. Our initial studies of these EpICD target pathways included genes with cell adhesion functions. Future studies on the regulation of the EpICD-Lef-1 regulated genes and their mechanisms of action in aggressive endometrial cancer will provide a better understanding of this gene network in endometrial cancer. Hypomethylation signatures of candidate loci in this regulatory network may present putative predictive markers of poor survival and which may be used to tailor individualized therapy.

Citation Format: Ya-Ting Hsu, Fei Gu, Yi-Wen Huang, Joseph Liu, Jianhua Ruan, Rui-Lan Huang, Chiou-Miin Wang, Chun-Liang Chen, Rohit R. Jadhav, Yao Wang, Victor X. Jin, Hung-Cheng Lai, David G. Mutch, Paul J. Goodfellow, Ian M. Thompson, Nameer B. Kirma, Tim H.M. Huang. EpCAM-mediated hypomethylation of BMP and cell adhesion genes is associated with advanced endometrial cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1376. doi:10.1158/1538-7445.AM2014-1376

Methylomics analysis identifies epigenetically silenced genes and implies an activation of β-catenin signaling in cervical cancer

Using DNA methylation biomarkers in cancer detection is a potential direction in clinical testing. Some methylated genes have been proposed for cervical cancer detection; however, more reliable methylation markers are needed. To identify new hypermethylated genes in the discovery phase, we compared the methylome between a pool of DNA from normal cervical epithelium (n = 19) and a pool of DNA from cervical cancer tissues (n = 38) using a methylation bead array. We integrated the differentially methylated genes with public gene expression databases, which resulted in 91 candidate genes. Based on gene expression after demethylation treatment in cell lines, we confirmed 61 genes for further validation. In the validation phase, quantitative MSP and bisulfite pyrosequencing were used to examine their methylation level in an independent set of clinical samples. Fourteen genes, including ADRA1D, AJAP1, COL6A2, EDN3, EPO, HS3ST2, MAGI2, POU4F3, PTGDR, SOX8, SOX17, ST6GAL2, SYT9, and ZNF614, were significantly hypermethylated in CIN3+ lesions. The sensitivity, specificity, and accuracy of POU4F3 for detecting CIN3+ lesions were 0.88, 0.82, and 0.85, respectively. A bioinformatics function analysis revealed that AJAP1, EDN3, EPO, MAGI2, and SOX17 were potentially implicated in β-catenin signaling, suggesting the epigenetic dysregulation of this signaling pathway during cervical cancer development. The concurrent methylation of multiple genes in cancers and in subsets of precancerous lesions suggests the presence of a driver of methylation phenotype in cervical carcinogenesis. Further validation of these new genes as biomarkers for cervical cancer screening in a larger population-based study is warranted.

Hypomethylation signature of tumor-initiating cells predicts poor prognosis of ovarian cancer patients

DNA methylation contributes to tumor formation, development and metastasis. Epigenetic dysregulation of stem cells is thought to predispose to malignant development. The clinical significance of DNA methylation in ovarian tumor-initiating cells (OTICs) remains unexplored. We analyzed the methylomic profiles of OTICs (CP70sps) and their derived progeny using a human methylation array. qRT-PCR, quantitative methylation-specific PCR (qMSP) and pyrosequencing were used to verify gene expression and DNA methylation in cancer cell lines. The methylation status of genes was validated quantitatively in cancer tissues and correlated with clinicopathological factors. ATG4A and HIST1H2BN were hypomethylated in OTICs. Methylation analysis of ATG4A and HIST1H2BN by qMSP in 168 tissue samples from patients with ovarian cancer showed that HIST1H2BN methylation was a significant and independent predictor of progression-free survival (PFS) and overall survival (OS). Multivariate Cox regression analysis showed that patients with a low level of HIST1H2BN methylation had poor PFS (hazard ratio (HR), 4.5; 95% confidence interval (CI), 1.4-14.8) and OS (HR, 4.3; 95% CI, 1.3-14.0). Hypomethylation of both ATG4A and HIST1H2BN predicted a poor PFS (HR, 1.8; 95% CI, 1.0-3.6; median, 21 months) and OS (HR, 1.7; 95% CI, 1.0-3.0; median, 40 months). In an independent cohort of ovarian tumors, hypomethylation predicted early disease recurrence (HR, 1.7; 95% CI, 1.1-2.5) and death (HR, 1.4; 95% CI, 1.0-1.9). The demonstration that expression of ATG4A in cells increased their stem properties provided an indication of its biological function. Hypomethylation of ATG4A and HIST1H2BN in OTICs predicts a poor prognosis for ovarian cancer patients.

Promoter hypomethylation of EpCAM-regulated bone morphogenetic protein gene family in recurrent endometrial cancer

PURPOSE

Epigenetic regulation by promoter methylation plays a key role in tumorigenesis. Our goal was to investigate whether altered DNA methylation signatures associated with oncogenic signaling delineate biomarkers predictive of endometrial cancer recurrence.

EXPERIMENTAL DESIGN

Methyl-CpG-capture sequencing was used for global screening of aberrant DNA methylation in our endometrial cancer cohort, followed by validation in an independent The Cancer Genome Atlas (TCGA) cohort. Bioinformatics as well as functional analyses in vitro, using RNA interference (RNAi) knockdown, were performed to examine regulatory mechanisms of candidate gene expression and contribution to aggressive phenotype, such as epithelial-mesenchymal transition (EMT).

RESULTS

We identified 2,302 hypermethylated loci in endometrial tumors compared with control samples. Bone morphogenetic protein (BMP) family genes, including BMP1, 2, 3, 4, and 7, were among the frequently hypermethylated loci. Interestingly, BMP2, 3, 4, and 7 were less methylated in primary tumors with subsequent recurrence and in patients with shorter disease-free interval compared with nonrecurrent tumors, which was validated and associated with poor survival in the TCGA cohort (BMP4, P = 0.009; BMP7, P = 0.007). Stimulation of endometrial cancer cells with epidermal growth factor (EGF) induced EMT and transcriptional activation of these genes, which was mediated by the epithelial cell adhesion molecule (EpCAM). EGF signaling was implicated in maintaining the promoters of candidate BMP genes in an active chromatin configuration and thus subject to transcriptional activation.

CONCLUSIONS

Hypomethylation signatures of candidate BMP genes associated with EpCAM-mediated expression present putative biomarkers predictive of poor survival in endometrial cancer.

Comprehensive methylome analysis of ovarian tumors reveals hedgehog signaling pathway regulators as prognostic DNA methylation biomarkers

Women with advanced stage ovarian cancer (OC) have a five-year survival rate of less than 25%. OC progression is associated with accumulation of epigenetic alterations and aberrant DNA methylation in gene promoters acts as an inactivating ?hit? during OC initiation and progression. Abnormal DNA methylation in OC has been used to predict disease outcome and therapy response. To globally examine DNA methylation in OC, we used next-generation sequencing technology, MethylCap-sequencing, to screen 75 malignant and 26 normal or benign ovarian tissues. Differential DNA methylation regions (DMRs) were identified, and the Kaplan?Meier method and Cox proportional hazard model were used to correlate methylation with clinical endpoints. Functional role of specific genes identified by MethylCap-sequencing was examined in in vitro assays. We identified 577 DMRs that distinguished (p < 0.001) malignant from non-malignant ovarian tissues; of these, 63 DMRs correlated (p < 0.001) with poor progression free survival (PFS). Concordant hypermethylation and corresponding gene silencing of sonic hedgehog pathway members ZIC1 and ZIC4 in OC tumors was confirmed in a panel of OC cell lines, and ZIC1 and ZIC4 repression correlated with increased proliferation, migration and invasion. ZIC1 promoter hypermethylation correlated (p < 0.01) with poor PFS. In summary, we identified functional DNA methylation biomarkers significantly associated with clinical outcome in OC and suggest our comprehensive methylome analysis has significant translational potential for guiding the design of future clinical investigations targeting the OC epigenome. Methylation of ZIC1, a putative tumor suppressor, may be a novel determinant of OC outcome.

Presacral teratoma in a Curarrino syndrome woman with an unreported insertion in MNX1 gene

OBJECTIVE

Currarino syndrome (CS) comprises a presacral mass, anorectal malformation, and a sacral bony defect. It is rarely reported in the gynecological field.

CASE REPORT

We describe here the case of a 26-year-old married woman with Currarino syndrome who presented with a presacral teratoma and a previously unreported insertion in MNX1 gene. She had had a pelvic teratoma diagnosed by laparoscopy 8 years previously. She was referred to our clinic because of the increasing size of the teratoma and associated compression symptoms. Computed tomography demonstrated a heterogeneous 12 cm mass in the presacral region. Spina bifida at S2eS5 was also noted. Laparotomy confirmed the diagnosis of presacral teratoma. Genetic analysis disclosed a triple CGC repeat insertion in exon 1 of MNX1, resulting in three in-frame shifts encoding for the amino acid alanine. No siblings had known similar symptoms.

CONCLUSION

Currarino syndrome is known to be an autosomal dominant disorder. The presence of constipation can lead to a diagnosis of the syndrome early in childhood. In sporadic cases diagnosis is late because of atypical symptoms. Delayed treatment of a presacral tumor may cause serious complications such as central nervous system infection or subsequent neurological dysfunction. In clinical practice, a presacral tumor with a sacral bony defect may indicate Currarino syndrome. Genetic analysis of the family may provide information on the hereditary traits of specific MNX1 mutation.

Methylomic analysis identifies frequent DNA methylation of zinc finger protein 582 (ZNF582) in cervical neoplasms

Background

Despite of the trend that the application of DNA methylation as a biomarker for cancer detection is promising, clinically applicable genes are few. Therefore, we looked for novel hypermethylated genes for cervical cancer screening.

Methods and Findings

At the discovery phase, we analyzed the methylation profiles of human cervical carcinomas and normal cervixes by methylated DNA immunoprecipitation coupled to promoter tiling arrays (MeDIP-on-chip). Methylation-specific PCR (MSP), quantitative MSP and bisulfite sequencing were used to verify the methylation status in cancer tissues and cervical scrapings from patients with different severities. Immunohistochemical staining of a cervical tissue microarray was used to confirm protein expression. We narrowed to three candidate genes: DBC1, PDE8B, and ZNF582; their methylation frequencies in tumors were 93%, 29%, and 100%, respectively. At the pre-validation phase, the methylation frequency of DBC1 and ZNF582 in cervical scraping correlated significantly with disease severity in an independent cohort (n = 330, both P<0.001). For the detection of cervical intraepithelial neoplasia 3 (CIN3) and worse, the area under the receiver operating characteristic curve (AUC) of ZNF582 was 0.82 (95% confidence interval  = 0.76–0.87).

Conclusions

Our study shows ZNF582 is frequently methylated in CIN3 and worse lesions, and it is demonstrated as a potential biomarker for the molecular screening of cervical cancer.

Growth inhibition of ovarian tumor-initiating cells by niclosamide

A recent hypothesis for cancer chemoresistance posits that cytotoxic survival of a subpopulation of tumor progenitors drives the propagation of recurrent disease, underscoring the need for new therapeutics that target such primitive cells. To discover such novel compounds active against drug-resistant ovarian cancer, we identified a subset of chemoresistant ovarian tumor cells fulfilling current definitions of cancer-initiating cells from cell lines and patient tumors using multiple stemness phenotypes, including the expression of stem cell markers, membrane dye efflux, sphere formation, potent tumorigenicity, and serial tumor propagation. We then subjected such stem-like ovarian tumor-initiating cells (OTIC) to high-throughput drug screening using more than 1,200 clinically approved drugs. Of 61 potential compounds preliminarily identified, more stringent assessments showed that the antihelmintic niclosamide selectively targets OTICs in vitro and in vivo. Gene expression arrays following OTIC treatment revealed niclosamide to disrupt multiple metabolic pathways affecting biogenetics, biogenesis, and redox regulation. These studies support niclosamide as a promising therapy for ovarian cancer and warrant further preclinical and clinical evaluation of this safe, clinically proven drug for the management of this devastating gynecologic malignancy.

Abstract 1110: Effect of miR-29 on cisplatin sensitivity of ovarian cancer cells

In clinical practice, the main dilemma to a successful ovarian cancer therapy is the development of drug resistance. The mounting evidence demonstrated that microRNAs (miRNAs) not only controlled cell proliferation, invasion and metastasis but also therapeutic resistance of ovarian cancer cell. Recently, we isolated CP70sps(CP70 side population spheres) from CP70 ovarian cancer cell line and proved that CP70sps exhibited more resistant to cisplatin than CP70. This phenomenon was correlated to other study which supported that side population of cancer cells was responsible for chemoresistance. In this study, we compared the expression of miRNAs between CP70sps and CP70 to investigate the role of miRNAs in cisplatin resistance of ovarian cancer cells. Our miRNA array and quantitative RT-PCR data showed that CP70sps expressed lower level of miR-29a/b/c family than CP70 cells and CP70sps4wks cells which were repopulation of CP70sps in attached condition. After knockdown of miR-29a/b/c family by miRNA inhibitors, reduction of miR-29a/b/c family enhanced cisplatin resistance of CP70 cells. However, there was no effect on cell cycle and proliferation rate in both CP70 cells and A2780, a parental cisplatin-sensitive cell line of CP70 cells. Downregulation of miR-29a/b/c family contributed cells to escape cisplatin-induced cell death through COL1A1 upregulation. Moreover, reduction of miR-29a/b/c increased phosphorylation of ERK1/2 and GSK3β to transduce survival signaling and reduced active form casepase-9 to avoid cell apoptosis. Furthermore, we found that either ectopic expression of miR-29 alone or combination of miR-29 with cisplatin treatment efficaciously reduced tumorigenicity of CP70 cells in immunodeficiency mice. Finally, we ascertained that the ovarian cancer patients with high expression of miR-29a had better overall survival rate. Taken together, our data demonstrated that the miR-29 family was a sensitizer for cisplatin treatment and might be associated with tumorigenecity of ovarian cancer cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1110. doi:1538-7445.AM2012-1110

Abstract 3433: Disruption of TGF-β signaling induces demethylation of E-cadherin promoter and reverses mesenchymal phenotype in ovarian cancer

The TGF-β signaling pathway plays an important role in controlling cell growth and differentiation. In advanced ovarian cancer, frequent TGF-β-induced metastasis or epithelial-mesenchymal transition (EMT) can be observed. This phenomenon is often associated with epigenetic silencing of epithelial marker, E-cadherin which can also be observed in ovarian cancer cell lines that demethylation treatment restored E-cadherin expression. We recently hypothesized that long term activation of TGF-β signaling may induce EMT phenotype by epigenetic silencing of E-cadherin and that inhibition of the signaling may restore E-cadherin and reverse EMT in ovarian cancer (Chou et al., Expert Opin Ther Targets 2010). In this study, we cloned the cDNA of the inhibitory SMAD, SMAD7 from a human immortalized ovarian surface epithelial cell, IOSE into pcDNA3.1 mammalian expression vector. The inhibitory effect of this SMAD7 expression vector on TGF-β signaling has been confirmed by reporter assay. We then stably transfected the SMAD7 expression vector into a mesenchymal ovarian cancer cell, CP70 in which E-cadherin is silenced by complete promoter methylation. Cells over-expressing SMAD7 showed up-regulation of SMAD7 and a decrease in SMAD2 phosphorylation while the control cells maintained a hyperphosphorylation of SMAD2 thus suggesting that TGF-β signaling is disrupted in SMAD7-overexpressing cells. We further examined the expression of E-cadherin from passage 5 up to 30 of the stable transfectants. Surprisingly, stable restoration of E-cadherin can only be observed from passage 20 and thereafter, of the SMAD7-overexpressing cells, while E-cadherin remained silence in the control cells. To investigate if this restoration is due to promoter demethylation of E-cadherin, we performed bisulphite pyrosequencing on the E-cadherin promoter CpG island spanning -586 to -12 of the region. Compared with control cells, consistent demethylation of E-cadherin promoter can be observed at 2 CpG sites located at -214 and -235 of the promoter such that gradual demethylation occurred from passage 5 to 30 of the SMAD7-overexpressing cells (passage 20, methylation% control vs SMAD7: 91% vs 67% at -235; 80% vs 52% at -214); while the rest of the CpG sites remained heavily methylated. This demethylation may be due to down-regulation of transcriptional repressor, TWIST after SMAD7 transfection. Additionally, one of the SMAD7 stable expression clones with highest restoration of E-cadherin showed decreased migration and invasion ability as determined by wound healing and invasion assay. Taken together, disruption of TGF-β signaling can induce demethylation of E-cadherin promoter and reverse EMT phenotype in ovarian cancer. The therapeutic potential of targeting TGF-β signaling pathway in inhibiting metastasis of ovarian cancer deserves further investigation.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3433. doi:10.1158/1538-7445.AM2011-3433