Drug repositioning of disulfiram induces endometrioid epithelial ovarian cancer cell death via the both apoptosis and cuproptosis pathways.

Various therapeutic strategies have been developed to overcome ovarian cancer. However, the prognoses resulting from these strategies are still unclear. In the present work, we screened 54 small molecule compounds approved by the FDA to identify novel agents that could inhibit the viability of human epithelial ovarian cancer cells. Among these, we identified disulfiram (DSF), an old alcohol-abuse drug, as a potential inducer of cell death in ovarian cancer. Mechanistically, DSF treatment significantly reduced the expression of the anti-apoptosis marker B-cell lymphoma/leukemia-2 (Bcl-2) and increase the expression of the apoptotic molecules Bcl2 associated X (Bax) and cleaved caspase-3 to promote human epithelial ovarian cancer cell apoptosis. Furthermore, DSF is a newly identified effective copper ionophore, thus the combination of DSF and copper was used to reduce ovarian cancer viability than DSF single treatment. Combination treatment with DSF and copper also led to the reduced expression of ferredoxin 1 and loss of Fe-S cluster proteins (biomarkers of cuproptosis). In vivo, DSF and copper gluconate significantly decreased the tumor volume and increased the survival rate in a murine ovarian cancer xenograft model. Thus, the role of DSF revealed its potential for used as a viable therapeutic agent for the ovarian cancer.

A miRNA-205-based model for prediction of the recurrence of endometrioid endometrial cancer.

AIM: To develop a miRNA-205 based model for prediction of the recurrence of endometrial cancer. METHODS: The FIGO (International Federation of Gynecology and Obstetrics) stage, grading, myometrial infiltration, lymph node status and miRNA-205 expression levels were extracted from 90 endometrioid endometrial cancer patients, recurrence related risk factors were analyzed by Cox regression analysis. A risk model was then developed. RESULTS: A total of 90 endometrial cancer patients were retrospectively included for the analysis. The FIGO stage and expression levels of miRNA 205 were independently associated with the recurrence-free survival of the patients. The FIGO stage and expression levels of miRNA 205 were used for a prognostic model of recurrence-free survival. The c-index of the model reached 0.764, and the output of the model (risk score) could stratify the patients into different groups on the risk of recurrence. CONCLUSION: A miRNA-205 based model could predict the risk of recurrence for endometrioid endometrial cancer, and the model could provide a risk stratification of patients by recurrence risk.

[Corrigendum] FOXO3a­mediated suppression of the self­renewal capacity of sphere­forming cells derived from the ovarian cancer SKOV3 cell line by 7­difluoromethoxyl­5,4'­di­n­octyl genistein.

Subsequently to the publication of this paper, an interested reader drew to the authors' attention that strikingly similar western blot data were shown in Fig. 2 (to portray the Nagon data in Fig. 2A and the CD133 data in Fig. 2B), and the same data also appeared to have been included in Fig. 4 (to show the p­FOXO3a data). After having examined their original data, the authors have realized that these figures were inadvertently assembled incorrectly. The corrected versions of Figs. 2 and 4, showing the correct data for the CD133 experiment in Fig. 2B and the p­FOXO3a experiment in Fig. 4, are shown opposite. Note that these errors did not significantly affect the results or the conclusions reported in this paper, and all the authors agree to this Corrigendum. Furthermore, the authors apologize to the readership for any inconvenience caused. [the original article was published in Molecular Medicine Reports 9: 1982­1988, 2014; DOI: 10.3892/mmr.2014.2012].

High Expression of MYL9 Indicates Poor Clinical Prognosis of Epithelial Ovarian Cancer.

BACKGROUND: The prognosis of Epithelial Ovarian Cancer (EOC) is poor, but the prognostic biomarkers are neither sensitive nor specific. Therefore, it is very important to search novel prognostic biomarkers for EOC. OBJECTIVES: The present study aimed to investigate Myosin Light Chain 9(MYL9) expression in Epithelial Ovarian Cancer (EOC) tissues (including paraffin-embedded and fresh tissue samples) and its relationship with clinicopathological characteristics, as well as its potential prognostic value in patients with EOC. METHODS: Between March 2009 and December 2018, all of 184 paraffin-embedded cancer tissues from patients with EOC and 41 paratumor tissues, pathologically confirmed at the Memorial Hospital of Sun Yat-sen University and Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, were collected for the present study and were assessed for MYL9 protein expression patterns using Immunohistochemistry (IHC). Furthermore, from August 2013 to November 2019, 16 fresh EOC tissues and their paired paratumor tissues, pathologically confirmed at the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University were analyzed using Reverse-Transcription Quantitative PCR (RT-qPCR) to detect MYL9 mRNA expression levels. RESULTS: The results showed that MYL9 expression was higher in cancer tissues compared with that in paratumor tissues, and MYL9 overexpression was associated with shorter Recurrence Free Survival (RFS) and Overall Survival (OS) of EOC patients. Furthermore, multivariate Cox model analysis indicated that MYL9 overexpression was an independent poor survival prediction in patients with EOC. CONCLUSION: MYL9 is upregulated in EOC and may serve as a useful patent of prognostic biomarker in EOC, and it may demonstrate an important value for the clinical treatment and supervision of patients with EOC.

The Use of Bionic Prodrugs for the Enhancement of Low Dose Radiotherapy.

Radiotherapy (RT) is a standard treatment strategy for many cancer types, but the need to frequently apply high doses of ionizing radiation in order to achieve therapeutic efficacy can cause severe harm to healthy tissues, leading to adverse patient outcomes. In an effort to minimize these toxic side effects, we herein sought to design a novel approach to the low-dose RT treatment of hypoxic tumors using a Tirapazamine (TPZ)-loaded exosome (EXO) nanoplatform (MT). This MT platform was synthesized via loading EXOs with TPZ, which is a prodrug that is activated when exposed to hypoxic conditions. MT application was able to achieve effective tumor inhibition at a relatively low RT dose (2 Gy) that was superior to standard high-dose (6 Gy) RT treatment with specific targeting to the hypoxic region of tumor. RT-mediated oxygen consumption further aggravated hypoxic conditions to improve TPZ activation and treatment efficacy. Together, our findings demonstrate the clinical promise of this MT platform as a novel tool for the efficient radiosensitization and treatment of cancer patients.

Sevoflurane alleviates hepatic ischaemia/reperfusion injury by up-regulating miR-96 and down-regulating FOXO4.

Hepatic ischaemia/reperfusion (I/R) injury represents an event characterized by anoxic cell death and an inflammatory response, that can limit the treatment efficacy of liver surgery. Ischaemic preconditioning agents such as sevoflurane (Sevo) have been highlighted to play protective roles in hepatic I/R injury. The current study aimed to investigate the molecular mechanism underlying the effects associated with Sevo in hepatic I/R injury. Initially, mouse hepatic I/R injury models were established via occlusion of the hepatic portal vein and subsequent reperfusion. The expression of forkhead box protein O4 (FOXO4) was detected using reverse transcription quantitative polymerase chain reaction and Western blot analysis from clinical liver tissue samples obtained from patients who had previously undergone liver transplantation, mouse I/R models and oxygen-deprived hepatocytes. The morphology of the liver tissues was analysed using haematoxylin-eosin (HE) staining, with apoptosis detected via TUNEL staining. Immunohistochemistry methods were employed to identify the FOXO4-positive cells. Mice with knocked out FOXO4 (FOXO4-KO mice) were subjected to I/R. In this study, we found FOXO4 was highly expressed following hepatic I/R injury. After treatment with Sevo, I/R modelled mice exhibited an alleviated degree of liver injury, fewer apoptotic cells and FOXO4-positive cells. FOXO4 was a target gene of miR-96. Knockdown of FOXO4 could alleviate hepatic I/R injury and decrease cell apoptosis. Taken together, the key observations of our study suggest that Sevo alleviates hepatic I/R injury by means of promoting the expression of miR-96 while inhibiting FOXO4 expression. This study highlights the molecular mechanism mediated by Sevo in hepatic I/R injury.

VPS33B interacts with NESG1 to suppress cell growth and cisplatin chemoresistance in ovarian cancer.

The pathogenesis and cisplatin chemoresistance of ovarian cancer (OC) are still unclear. Vacuolar protein sorting-associated 33B (VPS33B) has not been reported in OC to date. In this study, immunohistochemistry was used to detect VPS33B protein expression between OC and ovarian tissues. MTT, EdU, colony formation, cell cycle, in vivo tumorigenesis, western blot, ChIP, EMSA, co-immunoprecipitation (CoIP), qRT-PCR, and microconfocal microscopy were used to explore the function and molecular mechanisms of VPS33B in OC cells. The results of the present study demonstrated that VPS33B protein expression was obviously reduced in OC compared with that in ovarian tissues. Overexpressed VPS33B suppressed cell cycle transition, cell growth, and chemoresistance to cisplatin in vitro and in vivo. Analysis of the mechanism indicated that overexpressed VPS33B regulated the epidermal growth factor receptor (EGFR)/PI3K/AKT/c-Myc/p53/miR-133a-3p feedback loop and reduced the expression of the cell cycle factor CDK4. Nasopharyngeal epithelium-specific protein 1 (NESG1) as a tumor suppressor not only interacted with VPS33B, but was also induced by VPS33B by the attenuation of PI3K/AKT/c-Jun-mediated transcription inhibition. Overexpressed NESG1 further suppressed cell growth by mediating VPS33B-modulated signals in VPS33B-overexpressing OC cells. Finally, NESG1 induced VPS33B expression by reducing the inhibition of PI3K/AKT/c-Jun-mediated transcription. Our study is the first to demonstrate that VPS33B serves as a tumor suppressor, and VPS33B can interact with NESG1 to suppress cell growth and promote cisplatin sensitivity by regulating the EGFR/PI3K/AKT/c-Myc/p53/miR-133a-3p feedback loop in OC cells.

Co-Overexpression of GRK5/ACTC1 Correlates With the Clinical Parameters and Poor Prognosis of Epithelial Ovarian Cancer.

Background: The prognosis of epithelial ovarian cancer (EOC) is poor, and the present prognostic predictors of EOC are neither sensitive nor specific. Objective: The aim of this study was to search the prognostic biomarkers of EOC and to investigate the expression of G protein-coupled receptor kinase 5 (GRK5) and actin alpha cardiac muscle 1 (ACTC1) in EOC tissues (both paraffin-embedded and fresh-frozen tissues) and to explore their association with clinicopathological parameters and prognostic value in patients with EOC. Methods: A total of 172 paraffin-embedded cancer tissues of EOC patients diagnosed and operated at the memorial hospital of Sun Yat-sen University between December 2009 and March 2017 and 41 paratumor tissues were collected and the expression of GRK5 and ACTC1 was examined using immunohistochemistry. Furthermore, 16 fresh-frozen EOC tissues and their matched paratumor tissues were collected from the Integrated Hospital of Traditional Chinese Medicine, Southern Medical University, between August 2013 and November 2019 and subjected to reverse-transcription quantitative PCR analysis to detect the mRNA expression of GRK5 and ACTC1. Results: The expression of GRK5 and ACTC1 was both higher in cancer tissues than in paratumor tissues. GRK5 expression was positively correlated with ACTC1 expression. In addition, GRK5, ACTC1, and GRK5/ACTC1 expression was associated with the recurrence-free survival and overall survival of EOC patients. Furthermore, multivariate logistic regression analysis indicated that GRK5+/ACTC1+ co-expression, intestinal metastasis, postoperative chemotherapy, platinum resistance, and hyperthermic intraperitoneal chemotherapy were independent prognostic factors of EOC. Conclusion: GRK5 and ACTC1 are both upregulated in EOC compared with those in paratumor tissues. The co-expression of GRK5+/ACTC1+ rather than GRK5 or ACTC1 is an independent prognostic biomarker of EOC.

Isovitexin Inhibits Stemness and Induces Apoptosis in Hepatocellular Carcinoma SK-Hep-1 Spheroids by Upregulating miR-34a Expression.

BACKGROUND: We previously demonstrated that isovitexin (apigenin-6-C-glucoside, ISOV) suppressed the stemness of human Hepatocellular Carcinoma (HCC) cells. However, the mechanism of its action remains to be deciphered. OBJECTIVE: The current study was to examine whether ISOV regulates the miR-34a expression and hence suppresses the stemness of HCC SK-Hep-1 cells. METHODS: After identification of the stemness, apoptosis resistance and decreased miR-34a expression of spheres from SK-Hep-1 cells (SK-SC), we utilized transfection of a miR-34a mimic or inhibitor to investigate the effects of ISOV on miR-34a, Bcl-2, Bax and Mcl-1 expression in order to understand the mechanism underlying ISOV-mediated repression of stemness and promotion of apoptosis. RESULTS: Our results demonstrated that SK-SC displayed higher stemness and resistance to apoptosis, as well as reduced miR-34a levels compared to SK-Hep-1 cells. ISOV suppressed sphere and colony formation, and decreased CD44+ cell populations. In addition, ABCG2, ALDH1, and NANOG mRNA levels were decreased, while there was a concomitant increase in miR-34a levels. With regards to apoptosis-related proteins, ISOV increased Bax protein levels, and reduced Bcl-2 and Mcl-1 protein levels in SK-SC. Importantly, there was a cooperative effect when miR-34a was overexpressed in the presence of ISOV in SK-SC, and down-regulation of miR-34a attenuated the effects of ISOV in SK-Hep-1 cells. CONCLUSION: We suggest that ISOV-mediated miR-34a upregulation induces apoptosis and suppresses the stemness of SK-SC. Our data indicate that ISOV exhibits therapeutic potential for the treatment of HCC.

FOXO1 overexpression is correlated with poor prognosis in epithelial ovarian cancer.

OBJECTIVE: To investigate FOXO1 expression in epithelial ovarian cancer (EOC), and to explore its correlation with clinicopathological parameters and prognosis of EOC. METHODS: Two hundred and sixteen cases of paraffin-embedded EOC and 41 paratumor tissues from 2009 to 2017 that had been pathologically confirmed at the memorial hospital of Sun Yat-sen University were included in this study, and the expression of FOXO1 was performed by immunohistochemistry using a polyclonal antibody specific for FOXO1. RESULTS: FOXO1 protein expression is associated with Recurrence free and overall survival in EOC patients; In addition, FOXO1 expression is associated with age, FIGO stage, intraperitoneal metastasis, intestinal metastasis, vital status, intraperitoneal recurrence and differentiation grade; Moreover, in a multivariate model FOXO1 overexpression was an independent predictor of poor survival in EOC. CONCLUSION: FOXO1 may play a candidate oncogenic role in EOC, and FOXO1 is a useful independent prognostic marker in EOC, and it may provide a candidate target therapy in future.

miR-6089/MYH9/ß-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression.

The pathogenesis of ovarian cancer remains to be elucidated. Our previous study demonstrated that myosin heavy chain 9 (MYH9) overexpression was associated with poor prognosis of epithelial ovarian cancer. However, the mechanism of MYH9 and its regulation by microRNA (miR) is not clear. The results of the present study demonstrated that miR-6089 was one of the microRNAs targeting MYH9, and miR-6089 overexpression suppressed ovarian cancer cell proliferation, migration, invasion and metastasis in vivo and in vitro. Mechanistic studies confirmed that miR-6089 directly targeted MYH9 to inactivate the Wnt/ß-catenin signalling pathway and its downstream epithelial-to-mesenchymal transition (EMT), cell-cycle factors and c-Jun, whereas overexpression of MYH9 reversed the inhibitory effects of miR-6089 overexpression in ovarian cancer cells by upregulating the Wnt/ß-catenin and its downstream EMT, cell-cycle factors and c-Jun. Interestingly, miR-6089 was transcriptionally inhibited by c-Jun, a transcription factor which could be induced by MYH9 via the Wnt/ß-catenin pathway. Thus miR-6089/MYH9/ß-catenin/c-Jun formed a negative feedback loop in ovarian cancer. In clinical samples, miR-6089 negatively correlated with MYH9 expression. Our study is the first to demonstrate that miR-6089 serves as a tumor-suppressive miRNA, and miR-6089/MYH9/ß-catenin/c-Jun negative feedback loop inhibits ovarian cancer carcinogenesis and progression.

Chrysin Inhibits Proinflammatory Factor-Induced EMT Phenotype and Cancer Stem Cell-Like Features in HeLa Cells by Blocking the NF-κB/Twist Axis.

BACKGROUND/AIMS: TNF-α and TGF-ß associated epithelial-mesenchymal transition (EMT) occurs via NF-κB-dependent transcriptional upregulation of Twist1.Chrysin (ChR) is a major active ingredient ofpropolis, which inhibits various cancer cells and possesses anti-inflammatory activities. This study aimed to assess whether and how ChR inhibits proinflammatory cytokine-induced EMT phenotype and cancer stem-like cell (CSLC) features in the HeLa cell line. METHODS: HeLa cells were co-administered TNF-α (10.0 ng/mL) and TGF-ß (5.0 ng/mL) for 24h following TGF-ß (5.0 ng/mL) alone for 6 d in the presence or absence of ChR (5.0, 10.0 and 20.0µM). Then, the levels of EMT-related factors, multi-potential transcription factors, and stem cell markers were analyzed by immunoblot. Wound healing and tumor sphere formation assays were performed to assess the migration and self-renewal capabilities of cells, respectively. Overexpression and/or knockdown of NF-κBp65 and/or Twsit1 were used to explore the molecular mechanisms. RESULTS: The results showed that ChR inhibited EMT and CSLC properties in HeLa cells administered TNF-α after prolonged TGF-ß treatment, in a concentration-dependent fashion. NF-κBp65 knockdown and ChR(10.0µM) cooperatively enhanced the inhibition of NF-κBp65 and Twist1 expression, EMT, and CSLC properties. Conversely, overexpression of NF-κBp65 combined with ChR(10.0µM) antagonized such activities. Meanwhile, Twist1silencing or overexpression combined with ChR treatment did not affect NF-κBp65 levels, but also reduced or enhanced EMT and CSLC properties. Importantly, overexpressing Twist1 combined with ChR reversed the effects of NF-κBp65 knockdown and ChR. CONCLUSION: ChR inhibits proinflammatory cytokine-induced EMT and CSLC features in HeLa cells by blocking the NF-κB/Twist axis.

Genistein inhibits stemness of SKOV3 cells induced by macrophages co-cultured with ovarian cancer stem-like cells through IL-8/STAT3 axis.

BACKGROUND: Recent studies showed that macrophages co-cultured with ovarian cancer stem-like cells (OCSLCs) induced SKOV3 cell stemness via IL-8/STAT3 signaling. Genistein (GEN) demonstrates chemopreventive activity in inflammation-associated cancers. The present study aimed to examine whether and if GEN inhibits the stemness of SKOV3 and OVCA-3R cells induced by co-culture of THP-1 macrophages and SKOV3-derived OCSLCs. METHODS: The co-culture was treated with or without different concentrations (10, 20, and 40 µmol/L) of GEN for 24 h. Depletion or addition of IL-8 in Co-CM and knockdown or overexpression of STAT3 in THP-1 macrophages was performed to demonstrate the possible associated mechanisms. The combined effects of GEN and STAT3 knockdown were examined with the nude mouse modle by co-injection of SKOV3-derived OCSLCs with THP-1 macrophages. RESULTS: Our results showed that GEN down-regulated CD163 and p-STAT3 expression of THP-1 macrophage, decreased the levels of IL-10, increased the levels of IL-12 and nitric oxide (NO) in the conditioned medium, and reduced the clonogenic and sphere-forming capacities and the expression of CD133 and CD44 in SKOV3 cells induced by co-culture of THP-1 macrophages and OCSLCs in a dose-dependent manner. Moreover, depletion or addition of IL-8 enhanced or attenuated the effect of GEN. Additionally, knockdown or overepression of STAT3 in THP-1 macrophages potentiated or attenuated the inhibitory effects of GEN. Importantly, STAT3 overexpression retrieved the effects of IL-8 combined with GEN depletion on M2 polarization of THP-1 macrophages and stemness of SKOV3 cells induced by co-culture. The combination of GEN and STAT3 knockdown cooperatively inhibited the growth of tumors co-inoculated with OCSLCs/THP-1 macrophages in nude mice in vivo through blocking IL-8/STAT3 signaling. CONCLUSIONS: In summary, our findings suggested that GEN can inhibit the increased M2 polarization of macrophages and stemness of ovarian cancer cells by co-culture of macrophages with OCSLCs through disrupting IL-8/STAT3 signaling axis. This assisted GEN to be as a potential chemotherapeutic agent in human ovarian cancer.

Drug-target-disease network analysis of gene-phenotype connectivity for genistein in ovarian cancer.

PURPOSE: Genistein belongs to the group of isoflavones, which include powerful anticancer agents. Its antitumor properties have been intensively described in many cancers, but related studies assessing ovarian cancer are scarce. The aim of this study was to develop a new method of the underlying mechanisms of genistein's effects and broaden the perspective of targeted therapies in ovarian carcinoma. MATERIALS AND METHODS: Genistein targets were searched in the DrugBank database. Prediction of drug interactions with targets (including secondary targets) was performed with STRING database. Interaction pairs with overall score above 0.9 were recorded for protein-protein interaction (PPI) network generation based on the Cytoscape software. Genes with intense interconnections were grouped into a module. Then, PPI network modules with significance were assessed using Molecular Complex Detection (MCODE) analysis tool. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis was performed for the critical genes. Furthermore, disease targets were searched in Comparative Toxicogenomics Database (CTD). The overlapping targets were studied using a Kaplan-Meier analysis to evaluate ovarian carcinoma survival. RESULTS: A total of 13 direct targets and 372 secondary targets were identified for genistein and further analyzed with the MCODE analysis tool to identify critical genes. The top 72 genes were further assessed with KEGG. Then, the term "ovarian cancer" was searched in CTD, and 123 genes associated only with the marker "T" or "M" were recorded. Next, seven overlapping genes (CDKN1B, PTEN, EGFR, MAPK1, MAPK3, PIK3C, and AKT1) resulting from the intersection of three pathways and 123 genes were obtained from CTD. Elevated CDKN1B amounts showed correlation with overall survival (log-rank P=0.021) according to Kaplan-Meier analysis. CONCLUSION: The current findings indicated that drug-target-disease network analysis represents a useful tool in gene-phenotype connectivity for genistein in ovarian cancer. Our result also showed that CDKN1B is worthy of further research.

Co-culture of ovarian cancer stem-like cells with macrophages induced SKOV3 cells stemness via IL-8/STAT3 signaling.

Among recent concepts in the cancer biology field, the tumor microenvironment is highly associated with cancer stem cells, and plays a key role in tumor progression. This study aimed to explore the mechanism that the stemness induction of SKOV3 cell line by macrophages derived from THP-1 cells, which was co-cultured with SKOV3-derived ovarian cancer stem-like cells (OCSLCs). Sphere formation, soft agar colony formation, and expression levels of CD133 and CD44 were assessed to reflect OCSLC properties. ELISA was used to evaluate secretion profile changes in macrophages co-cultured with or without SKOV3-derived OCSLCs. For mechanistic evaluation, rhIL-8, IL-8 neutralizing antibody (IL-8 Ab), signal transducer and activator of transcription 3 (STAT3) shRNA and STAT3 cDNA were used. The results showed that IL-10, VEGF, MMP-9, IL-8 secretion and CD163 and STAT3 expression levels in macrophages co-cultured with OCSLCs were increased compared with those from THP-1 cells, while IL-12 and NO amounts were significantly reduced, reflecting M2 macrophage polarization. Addition of rhIL-8 to THP-1 cell conditioned media promoted M2 macrophage polarization and stemness in SKOV3 cells, which were suppressed by IL-8 Ab addition to co-culture conditioned media. Consistently, overexpression of STAT3 induced M2 macrophage polarization and stemness in SKOV3 cells, which were inhibited by STAT3 knockdown in macrophages from THP-1 cells. Importantly, STAT3 overexpression rescued the effects of IL-8 Ab on M2 macrophage polarization and stemness in SKOV3 cells. These results suggested that stemness induction in SKOV3 cells by macrophages co-cultured with SKOV3-derived OCSLCs involved IL-8/STAT3 signaling.

Let-7d increases ovarian cancer cell sensitivity to a genistein analog by targeting c-Myc.

c-Myc is a key oncogenic transcription factor that participates in tumor pathogenesis. In this study, we found that levels of c-Myc mRNA and protein were higher in early ovarian cancer tissues than normal ovary samples. Increased c-Myc levels correlated positively with clinical stage I (Ia+b/Ic) in ovarian cancer patients. Patients with higher nuclear c-Myc expression had shorter overall survival times than patients with low c-Myc expression. Knocking down c-Myc sensitized ovarian cancer cells to 7-difluoromethoxyl-5,4'-di-n-octylgenistein (DFOG), a novel synthetic genistein analogue that suppressed PI3K/AKT signaling in vitro and in vivo. Finally, c-Myc was confirmed to be a direct target of let-7d, and let-7d-induced suppression of c-Myc increased the DFOG-sensitivity of ovarian cancer cells. These results indicate that nuclear c-Myc expression is an unfavorable factor in early ovarian cancer, and that let-7d increases ovarian cancer cell sensitivity to DFOG by suppressing c-Myc and PI3K/AKT signaling.

Suppressing miR-199a-3p by promoter methylation contributes to tumor aggressiveness and cisplatin resistance of ovarian cancer through promoting DDR1 expression.

BACKGROUND: Discoidin Domain Receptor 1 (DDR1) belongs to the family of collagen receptor tyrosine kinases that confers the progression of various cancers. Aberrant expression of DDR1 was detected in several human cancers including ovarian cancer, which had been shown to increase the migration and invasion of tumor cells. However, the precise mechanisms underlying the abnormal expression of DDR1 in ovarian cancer has not been well investigated in previous studies. RESULTS: In this work, a negative correlation between DDR1 and a tumor suppressor miRNA, miR-199a-3p, was observed in ovarian cancer tissues. Furthermore, in vitro experimental results confirmed that miR-199a-3p decreased the expression of DDR1 via targeting the 3'UTR of DDR1 mRNA. To explore the mechanisms for miR-199a-3p silence in ovarian cancer, the methylation status of the miR-199a promoter was analyzed in ovarian epithelial or cancer cells by methylation-specific PCR and bisulphite sequencing. As expected, the miR-199a promoter was hypermethylated in ovarian cancer cells but not in normal ovarianepithelial cells. Interestingly, knockdown of DNA methyltransferase 3A (DNMT3A) notably increased miR-199a-3p level and then attenuated the expression of DDR1 in ovarian cancer cells, which suggested that DNMT3A was responsible for the miR-199a promoter hypermethylation. Phenotype experiments showed that overexpression of miR-199a-3p significantly impaired the migratory, invasive, and tumorigenic capabilities of ovarian cancer cells as well as enhanced cisplatin resistance through inhibiting DDR1 expression. CONCLUSION: These findings demonstrate a critical role of miR-199a-3p/DDR1 pathway in ovarian cancer development.

Inactivation of AKT, ERK and NF-κB by genistein derivative, 7-difluoromethoxyl-5,4'-di-n-octylygenistein, reduces ovarian carcinoma oncogenicity.

Cancer stem cells (CSCs) have central functions in cancer formation and development. Aberrant expression of AKT, ERK and NF-κB signaling pathways have been reported in several types of CSCs. Phytochemicals from dietary compounds possess anti-CSC properties, and have been characterized as promising therapeutic agents for the prevention and treatment of many types of cancers. We previously showed that the newly synthesized genistein derivative, 7-difluoromethoxyl-5,4'-di-n-octylygenistein (DFOG), can inhibit the self-renewal ability of ovarian cancer stem cells (OVCSLCs). In the present study, we further assessed whether various signaling pathways are regulated by DFOG. We found that spheroids derived from the SKOV3 cell line possessed OVCSLC properties and DFOG efficiently inhibited the stemness of the OVCSLCs. In addition, the suppression of spheroid and colony formation by DFOG was associated with inhibition of AKT and ERK1/2 protein phosphorylation, and NF-κB activity in OVCSLCs from the SKOV3 cells. Importantly, DFOG inhibited the oncogenicity of the OVCSLCs by activation of FoxO3a and/or inactivation of FoxM1 by the targeting of multiple pro-survival (AKT and ERK1/2) and proinflammatory (NF-κB) pathways, providing a new avenue for the treatment of ovarian carcinoma in humans.