Epithelial Ovarian Cancer Tumorigenesis Research Articles

UBP43 promotes epithelial ovarian carcinogenesis via activation of β-catenin signaling pathway.

Dysregulation of the deubiquitinating protease, UBP43, has been implicated in many human diseases, including cancer. Here, we evaluated the functional significance and mechanism of action of UBP43 in epithelial ovarian cancer. We found that UBP43 was significantly upregulated in the tumor tissues of patients with epithelial ovarian cancer. Similar results were observed in OVCAR-3, Caov-3, TOV-112D, A2780, and SK-OV-3 cells. Furthermore, in vitro functional assays of A2780 and TOV-112D cells demonstrated that UBP43 overexpression promoted cell proliferation, migration, and invasion. Upregulation of UBP43 might result in epithelial-mesenchymal transition by inducing the nuclear transport of β-catenin, which was accompanied by enhanced N-cadherin but decreased E-cadherin expression. These malignant phenotypes were reversed by UBP43 silencing. Further investigation revealed that the knockdown of UBP43 inhibited cell proliferation by inducing a cell cycle arrest at the G2/M phase. The oncogenic characteristics of UBP43 were validated in a subcutaneous xenograft mouse model. In vivo, tumor growth was delayed in the UBP43-silenced group but accelerated after UBP43 overexpression. Finally, we demonstrated that β-catenin is a key protein in the UBP43-mediated malignant development of epithelial ovarian cancer. Specifically, overexpression of UBP43 decreased the ubiquitination degradation of β-catenin and enhanced its protein stability. Also, we observed that the downstream genes of beta-catenin such as cyclin D1, MMP2, and MMP9 were upregulated due to UBP43 overexpression. Thus, we concluded that UBP43 promoted epithelial ovarian cancer tumorigenesis and metastasis through activation of the β-catenin pathway, suggesting that UBP43 may be a potential therapeutic target for this intractable disease.

Silencing of lncRNA SNHG17 inhibits the tumorigenesis of epithelial ovarian cancer through regulation of miR-485-5p/AKT1 axis

BackgroundEpithelial ovarian cancer (EOC) stands up for about 90% of ovarian cancer cases, which is the frequent cause of death among women. LncRNAs are involved in progression of EOC. Meanwhile, lncRNA SNHG17 was upregulated in EOC, while the detailed function of SNHG17 in EOC remains unclear. MethodsProtein and mRNA levels were assessed by western blot and RT-qPCR, respectively. The function of SNHG17 in EOC cells was tested by CCK-8, Ki-67 staining, flow cytometry and transwell assay. Dual luciferase was applied for assessing the relation among SNHG17, miR-485-5p and AKT1. Furthermore, in vivo experiments were applied to test the impact of SNHG17 in EOC. ResultsSNHG17 knockdown reduced the proliferation and promoted the apoptosis of EOC cells. Consistently, si-SNHG17 obviously reduced the invasion and epithelial-to-mesenchymal transition (EMT) process of EOC cells. MiR-485-5p was proved to be the target miRNA of SNHG17, and SNHG17 negatively regulated the level of miR-485-5p. MiR-485-5p inhibitor significantly abolished the anti-tumor impact of si-SNHG17 on EOC. AKT1 was identified to be targeted by miR-485-5p, and miR-485-5p negatively modulated AKT1 and p-mTOR levels. Moreover, miR-485-5p mimics reduced the proliferation, migration and promoted the apoptosis of EOC cells via targeting AKT1. Furthermore, si-SNHG17 markedly suppressed EOC growth in vivo. ConclusionSNHG17 silencing inhibits the development of EOC via regulation of miR-485-5p/AKT1 axis. Thus, our study might supply a novel strategy against EOC.

Targeting and neutralizing human epididymis protein 4 by novel nanobodies to suppress ovarian cancer cells and attenuate cisplatin resistance

Human epididymis protein 4 (HE4) is a glycoprotein secreted by epithelial ovarian cancer (EOC) cells and is a novel and specific biomarker for diagnosing and prognosing EOC. Previous studies have shown that overexpression of HE4 is correlated with EOC tumorigenesis and chemoresistance. However, less has been reported regarding the direct effect of the secreted HE4 protein as an autocrine factor in EOC cells. Here, we investigated the molecular mechanism of the secretory form of HE4 on the growth of EOC cells by applying nanobodies with a targeted interaction of free HE4. Three anti-HE4 nanobodies were selected from an immune library by phage display. HE4 secreted by serum-free cultured OVCAR3 cells increased and was effectively neutralized by anti-HE4 nanobodies, which inhibited cell viability. Treatment with the anti-HE4 nanobody 1G8 decreased Bcl-2 expression and increased BAX, cleaved PARP, and p53 levels, resulting in apoptosis of OVCAR3 cells. Moreover, 1G8 significantly improved the cisplatin response of OVCAR3 cells. Our data suggest that secretory HE4 played a novel pro-survival autocrine role and was a target of the anti-HE4 nanobody to improve the therapeutic effects of cisplatin-based chemotherapy.

EPDR1, Which Is Negatively Regulated by miR-429, Suppresses Epithelial Ovarian Cancer Progression via PI3K/AKT Signaling Pathway.

Epithelial ovarian cancer (EOC) is the main pathological type of ovarian cancer. In this study, we found that ependymin-related 1 (EPDR1) was remarkably downregulated in EOC tissues, and low EPDR1 expression was associated with International Federation of Gynecology and Obstetrics (FIGO) stage, metastasis, and poor prognosis. We confirmed that EPDR1 overexpression dramatically suppressed EOC cell proliferation, migration, and invasion in vitro and in vivo. Mechanistically, EPDR1 inhibited EOC tumorigenesis and progression, at least in part, through the repression of the PI3K (Phosphoinositide 3-kinase)/AKT (AKT Serine/Threonine Kinase 1) signaling pathway. Furthermore, the expression and function of EPDR1 were regulated by miR-429, as demonstrated by luciferase reporter assays and rescue experiments. In conclusion, our study validated that EPDR1, negatively regulated by miR-429, played an important role as a tumor-suppressor gene in EOC development via inhibition of the PI3K/AKT pathway. The miR-429/EPDR1 axis might provide novel therapeutic targets for individualized treatment of EOC patients in the future.

STAT1-Induced Upregulation lncRNA LINC00958 Accelerates the Epithelial Ovarian Cancer Tumorigenesis by Regulating Wnt/β-Catenin Signaling.

Background Growing studies have demonstrated that long noncoding RNAs (lncRNAs) play important roles in tumor progression. In this study, we aimed to explore the potential roles of lncRNA LINC00958 (LINC00958) and its biological functions in epithelial ovarian cancer (EOC). Methods The expression of LINC00958 in 11 cases of EOC and adjacent nontumor specimens and five cell lines was detected by qRT-PCR. CCK-8, colony formation, and flow cytometry assays were conducted to study the cell viabilities of EOC cells. Wound scratch and transwell analyses were carried out for the examination of cell invasion and migration of EOC cells. The targeting associations between LINC00958 and STAT1 were demonstrated by ChIP analyses combined with luciferase reporter assays. The related proteins of Wnt/β-catenin signaling were determined using RT-PCR. Results Higher levels of LINC00958 were observed in EOC tissues and cell lines. Our data also revealed that high LINC00958 expression was partly induced by STAT1. Functionally, knockdown of LINC00958 suppressed the proliferation, migration, and invasion of EOC cells. Mechanistic investigation showed that the inhibitory effect of LINC00958 knockdown on EOC cells was mediated by the Wnt/β-catenin signaling. Conclusion Our findings suggested that STAT1-induced overexpression of LINC00958 promoted EOC progression by modulating Wnt/β-catenin signaling.

Calcineurin Gamma Catalytic Subunit PPP3CC Inhibition by miR-200c-3p Affects Apoptosis in Epithelial Ovarian Cancer.

Epithelial ovarian cancer (EOC) outpaces all the other forms of the female reproductive system malignancies. MicroRNAs have emerged as promising predictive biomarkers to therapeutic treatments as their expression might characterize the tumor stage or grade. In EOC, miR-200c is considered a master regulator of oncogenes or tumor suppressors. To investigate novel miR-200c-3p target genes involved in EOC tumorigenesis, we evaluated the association between this miRNA and the mRNA expression of several potential target genes by RNA-seq data of both 46 EOC cell lines from Cancer Cell line Encyclopedia (CCLE) and 456 EOC patient bio-specimens from The Cancer Genome Atlas (TCGA). Both analyses showed a significant anticorrelation between miR-200c-3p and the protein phosphatase 3 catalytic subunit γ of calcineurin (PPP3CC) levels involved in the apoptosis pathway. Quantitative mRNA expression analysis in patient biopsies confirmed the inverse correlation between miR-200c-3p and PPP3CC levels. In vitro regulation of PPP3CC expression through miR-200c-3p and RNA interference technology led to a concomitant modulation of BCL2- and p-AKT-related pathways, suggesting the tumor suppressive role of PPP3CC in EOC. Our results suggest that inhibition of high expression of miR-200c-3p in EOC might lead to overexpression of the tumor suppressor PPP3CC and subsequent induction of apoptosis in EOC patients.

Circ-NOLC1 promotes epithelial ovarian cancer tumorigenesis and progression by binding ESRP1 and modulating CDK1 and RhoA expression

Circular RNAs (circRNAs) play important roles in cancer tumorigenesis and progression, representing prognostic biomarkers and therapeutic targets. In this case, we demonstrated the role of circ-NOLC1 in epithelial ovarian cancer (EOC). Our results have shown that Circ-NOLC1 expression was higher in EOC tissues than in normal tissues, and was positively associated with FIGO stage, differentiation. Among ovarian cancer cell lines, circ-NOLC1 expression was the highest in A2780, and lowest in CAOV3. Overexpression of circ-NOLC1 in CAOV3 cells increased cell proliferation, migration, and invasion ability, whereas silencing of circ-NOLC1 in A2780 cells had the opposite effect: however, neither circ-NOLC1 downregulation nor overexpression influenced NOLC1 mRNA expression. In nude mice with subcutaneous tumors, circ-NOLC1 downregulation decreased tumor growth. Bioinformatic analysis and RNA-binding protein immunoprecipitation showed that circ-NOLC1 could bind to ESRP1. In addition, the overexpression of circ-NOLC1 significantly increased ESRP1, RhoA, and CDK1 protein and mRNA expression level; circ-NOLC1 downregulation had the opposite effects. The tumor-promoting effect of circ-NOLC1 was inhibited by knockdown of ESRP1, CDK1, or RhoA expression in circ-NOLC1-overexpressing cells, which might act by modulating RhoA and CDK1 expression. In conclusion, our study demonstrated that Circ-NOLC1 might promote EOC tumorigenesis and development by binding ESRP1 and modulating CDK1 and RhoA expression.

Overexpression of long noncoding RNA HOXB-AS3 indicates an unfavorable prognosis and promotes tumorigenesis in epithelial ovarian cancer via Wnt/β-catenin signaling pathway.

Long noncoding RNA HOXB cluster antisense RNA 3 (HOXB-AS3) has been reported to be dysregulated in several tumors. The present study mainly aims at the investigation in how HOXB-AS3 works in epithelial ovarian cancer (EOC) and to elucidate the mechanism involved. Initially, ‘GEPIA’ was mined to examine the differential expression levels and prognostic value of HOXB-AS3 in EOC patients. The expression of HOXB-AS3 in EOC cell lines and patient specimens was examined with quantitative RT-PCR. Simultaneously, the correlation of HOXB-AS3 expression with a variety of clinicopathological factors and patient survival was analyzed. MTT, colony formation and flow cytometry assays were performed to analyze the cell viability of EOC cells. Wound healing and Transwell assays were carried out to determine EOC cells’ capability of migrating and invading. The impact of HOXB-AS3 on EMT and Wnt/β-catenin signaling was explored with the approach of Western blot. We found that in both EOC cell lines and tissues, HOXB-AS3 expression was significantly up-regulated, and its high expression was an independent prognostic marker of poor outcome for EOC patients. In vitro loss-of-function assays revealed that HOXB-AS3 knockdown inhibited EOC cells proliferation, migration, invasion and EMT, and induced EOC cells’ apoptosis. Furthermore, we validated that down-regulated HOXB-AS3 attenuated the activity of Wnt/β-catenin signaling to suppress the invasion, migration and proliferation of EOC cells. To sum up, the present study came up with the conclusion that HOXB-AS3 acts as an oncogenic gene in EOC progression through HOXB-AS3-Wnt/β-catenin signaling regulation, providing a novel insight into EOC tumorigenesis.

LINC00968 accelerates the progression of epithelial ovarian cancer via mediating the cell cycle progression.

The aim of this study was to clarify the potential role of LINC00968 in the progression of epithelial ovarian cancer (EOC) and the underlying mechanism. The relative expression level of LINC00968 in EOC tissues (n=40) and normal ovarian tissues (n=40) was determined by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). LINC00968 expression in human-derived ovarian cancer cell lines was examined by qRT-PCR as well. After transfection of LINC00968 small-interfering RNA (siRNA) in ovarian cancer cells, cell cycle progression and cell proliferation were evaluated through flow cytometry, Cell Counting Kit-8 (CCK-8) and colony formation assay, respectively. Tumor xenograft was conducted in nude mice to elucidate the function of LINC00968 in EOC tumorigenesis in vivo. Furthermore, the relative expression levels of cell cycle factors and protein kinase B/extracellular-signal-regulated kinase (AKT/ERK) in ovarian cancer cells influenced by LINC00968 were detected by Western blot. LINC00968 was significantly up-regulated in EOC tissues when compared with normal control tissues. Meanwhile, LINC00968 expression was positively correlated with the prognosis of EOC. Transfection of LINC00968 siRNA in HEY and HO8910 cells markedly attenuated proliferative ability and arrested cell cycle in the G1 phase. Knockdown of LINC00968 remarkably suppressed tumor growth of EOC in nude mice. The silence of LINC00968 significantly downregulated Cyclin D, Cyclin E and CDK4, whereas upregulated p16 and p21. In addition, AKT and ERK pathways were inhibited by knockdown of LINC00968 in ovarian cancer cells. LINC00968 expression is markedly upregulated in EOC. Meanwhile, it arrests the cell cycle in the G1 phase by inhibiting the ERK and AKT pathways, thus accelerating EOC progression.

CREB1 induced lncRNA HAS2-AS1 promotes epithelial ovarian cancer proliferation and invasion via the miR-466/RUNX2 axis

Accumulating evidence has indicated the vital roles of long noncoding RNA (lncRNA) in the epithelial ovarian cancer (EOC). However, the function of lncRNA HAS2-AS1 in EOC is still unclear. This study aims to investigate the expression and role of HAS2-AS1 in EOC. In the cells and tissue of EOC, HAS2-AS1 expression was markedly up-regulated. Besides, the overexpression of HAS2-AS1 indicated the poor clinical outcome of EOC patients. Transcription factor CREB1 could bind with the promoter of HAS2-AS1 and activate its transcriptional expression. Functionally, HAS2-AS1 knockdown suppressed the proliferation, invasion and tumor growth of EOC cells in vitro and in vivo. Mechanical investigation found that HAS2-AS1 could relive the RUNX2 protein expression via sponging the miR-466, acting as miRNA sponge. In conclusion, this finding suggests the CREB1/HAS2-AS1/miR-466/RUNX2 axis in the in the EOC tumorigenesis, providing the novel insight for the molecular mechanism of EOC.

Septin-2 is overexpressed in epithelial ovarian cancer and mediates proliferation via regulation of cellular metabolic proteins.

ABSTRACTEpithelial Ovarian Cancer (EOC) is associated with dismal survival rates due to the fact that patients are frequently diagnosed at an advanced stage and eventually become resistant to traditional chemotherapeutics. Hence, there is a crucial need for new and innovative therapies. Septin-2, a member of the septin family of GTP binding proteins, has been characterized in EOC for the first time and represents a potential future target. Septin-2 was found to be overexpressed in serous and clear cell human patient tissue compared to benign disease. Stable septin-2 knockdown clones developed in an ovarian cancer cell line exhibited a significant decrease in proliferation rates. Comparative label-free proteomic analysis of septin-2 knockdown cells revealed differential protein expression of pathways associated with the TCA cycle, acetyl CoA, proteasome and spliceosome. Further validation of target proteins indicated that septin-2 plays a predominant role in post-transcriptional and translational modifications as well as cellular metabolism, and suggested the potential novel role of septin-2 in promoting EOC tumorigenesis through these mechanisms.

Ovarian cancer and inflammation. Part 2. Anti-inflammatory cytokines

Inflammation plays a key role in epithelial ovarian cancer tumorigenesis and progression. The growth and progression of epithelial ovarian cancer may be due to local cytokine-induced immunosu-ppression, which may lead to an immunity impairment. Thus, cytokine antagonism may be an essential factor in the treatment of ovarian cancer. Based on the increased knowledge on the role of the immune system in ovarian cancer, major improvements are to be expected of immunotherapy based treatment of this disease. This article aims to summarize the current literature views on the evidence for a role for chronic inflammation with a specific focus on anti-inflammatory cytokines.

MiR-542-3p, a microRNA targeting CDK14, suppresses cell proliferation, invasiveness, and tumorigenesis of epithelial ovarian cancer

MicroRNA-542-3p (miR-542-3p) has been implicated in several cancers; however, its precise role in ovarian cancer is unclear. In this study, we found that miR-542-3p was significantly downregulated in epithelial ovarian cancer (EOC) tissues and cell lines. Functional assays showed that overexpression of miR-542-3p suppressed tumor cell proliferation, migration, and invasion in vitro, whereas miR-542-3p knockdown dramatically promoted tumor cell proliferation and invasion. An in vivo assay also revealed that miR-542-3p overexpression significantly attenuated tumor growth. Mechanistically, the gene of cyclin-dependent kinase 14 (CDK14) was identified as a novel target of miR-542-3p. CDK14 overexpression reversed the suppressive effects of miR-542-3p in ovarian cancer cells. Collectively, these results suggest that miR-542-3p functions as a tumor-suppressive miRNA in ovarian cancer by directly targeting CDK14. Our data provide novel insights into potential future treatments for patients with ovarian cancer.

Natural antisense transcript of hypoxia-inducible factor 1 regulates hypoxic cell apoptosis in epithelial ovarian cancer.

PurposeHypoxia is a key stress that triggers apoptosis in various tumors, including epithelial ovarian cancer (EOC). Previous researches identified a hypoxia-upregulated lncRNA named “a natural antisense transcript of hypoxia-inducible factor 1 (aHIF)” in some tumors. However, the contribution of aHIF to EOC remains unclear. Here, we aimed to investigate the expression, function, and underlying mechanisms of aHIF in EOC progression under hypoxia.Materials and methodsExpression levels of aHIF in EOC tissues were tested. In vitro and in vivo assays were conducted to explore the function and mechanism of aHIF in hypoxia-induced EOC progression.ResultsaHIF levels were increased in EOC tissues and were upregulated by hypoxia in EOC cells. Functional data revealed that aHIF knockdown accelerated cell apoptosis under hypoxia and inhibited EOC tumorigenesis and tumor growth in vivo. Additionally, aHIF overexpression inhibited cell apoptosis and enhanced cell proliferation under hypoxia in EOC. Mechanistically, the dysregulation of certain key mitochondrial apoptosis pathway-related genes, including Bcl-2, Bax, Caspase-7, and Caspase-9, may partially explain aHIF-regulated EOC apoptosis and growth under hypoxia.ConclusionThese data provide the first convincing evidence that aHIF may inhibit EOC apoptosis and thereby promote tumor growth through activation of the mitochondrial apoptosis pathway under hypoxia. Our findings help clarify the role of lncRNA in hypoxia-induced EOC progression.

Circular RNA profiling reveals circEXOC6B and circN4BP2L2 as novel prognostic biomarkers in epithelial ovarian cancer.

Circular RNAs (circRNAs) are regarded as a novel class of widespread endogenous non-coding RNAs, which may play important roles in tumorigenesis by regulating gene expression. Nevertheless, the characterization of circRNAs in epithelial ovarian cancer(EOC) remains largely unknown. This study aimed to investigate circRNA expression profiles in EOC. A total of 54EOC specimens and 54normal ovarian tissues (controls) were collected. circRNA-sequencing based circRNA expression profiles were identified in 4EOC specimens and compared with 4normal ovarian tissues. circRNA-sequencing data were validated by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in the 54EOC specimens and 54normal ovarian tissues. The association between differentially expressed circRNAs and various clinicopathological features of EOC was determined using a non-parametric test. Univariate analysis was performed using the log-rank test. A total of 4,388circRNAs (2,556up- and 1,832downregulated; fold change of≥2 and P<0.05) were identified to be differentially expressed in the EOC specimens compared with the normal ovarian tissues. Of these, the levels of 6circRNAs (circBNC2, circEXOC6B, circFAM13B, circN4BP2L2, circRHOBTB3 and circCELSR1) were confirmed by RT-qPCR. Our data further indicated that these 6circRNAs were associated with various clinicopathological features of EOC. More importantly, we found that circEXOC6B and circN4BP2L2 may act as novel prognostic biomarkers in patients with EOC. On the whole, the results of this study indicate that differentially expressed circRNAs may participate in the pathogenesis of EOC and may thus have potential for use as novel diagnostic and prognostic biomarkers for EOC. Future experiments with larger sample sizes are required to verify the current findings and illuminate the regulatory mechanisms of action of circRNAs in the tumorigenesis of EOC.

LncSOX4 serves an oncogenic role in the tumorigenesis of epithelial ovarian cancer by promoting cell proliferation and inhibiting apoptosis

Epithelial ovarian cancer is one of the primary causes of gynecological cancer mortality. Increasing evidence has suggested that long non-coding RNAs (lncRNAs) may serve a pivotal role in cancer development. To determine whether Lnc SRY-box 4 (SOX4), an lncRNA, promotes the self-renewal of liver tumor cells and contributes to the development of epithelial ovarian cancer, the present study investigated the expression of LncSOX4 in clinical epithelial ovarian cancer tissues and non-cancer controls by reverse transcription-quantitative polymerase chain reaction analysis. In addition, siRNA targeting LncSOX4 was designed and transfected into epithelial ovarian cancer cells to further assess the effect of knocking out LncSOX4 on cellular apoptosis, cell viability, proliferation and the cell cycle. The results demonstrated that the LncSOX4 expression level was significantly upregulated in epithelial ovarian cancer tissues (3.98 vs. 1.71, P<0.001). Silencing LncSOX4 in the SKOV3 and OVCAR3 cell lines significantly impaired cell proliferation (P<0.001). Cell cycle assays revealed that the proportion of cells in the G0/G1 phase increased significantly, whereas those in the S phase and G2/M phase decreased. Apoptosis rate additionally increased following knockdown of LncSOX4 in the two cell lines. Furthermore, it was observed that an increased LncSOX4 expression level was positively associated with larger tumor sizes, more advanced tumor grade and more distant metastases.

Long Noncoding RNA CCAT2 Knockdown Suppresses Tumorous Progression by Sponging miR-424 in Epithelial Ovarian Cancer.

Epithelial ovarian cancer (EOC) is the one of most common gynecological malignant tumors with high mortality. A series of long noncoding RNAs (lncRNAs) have been validated to play a vital role in EOC tumorigenesis. Colon cancer-associated transcript 2 (CCAT2) has been verified as an oncogenic lncRNA in multiple tumors; however, the role of CCAT2 in EOC genesis is still unclear. The purpose of the present study was to probe the function of CCAT2 on EOC. Preliminary experiments found that CCAT2 expression was significantly upregulated in EOC tissues and cell lines compared to noncancerous tissue and cells. CCAT2 knockdown induced by interfering oligonucleotides could inhibit proliferation and promote apoptosis and induce cell cycle arrest at the G0/G1 phase. Bioinformatics analysis predicted that miR-424 targeted CCAT2, which was confirmed by luciferase reporter assay. Moreover, the miR-424 inhibitor rescued the tumorigenesis inhibition induced by CCAT2 knockdown. In summary, our findings illustrate that CCAT2 acts as competing endogenous RNA (ceRNA) or sponge via negatively targeting miR-424, providing a novel diagnostic marker and therapeutic target for EOC.

LncRNA myocardial infarction-associated transcript promotes cell proliferation and inhibits cell apoptosis by targeting miR-330-5p in epithelial ovarian cancer cells.

IntroductionLong non-coding RNAs (lncRNAs) have been shown to have great importance in cancer development and progression. However, the mechanism of lncRNAs in epithelial ovarian cancer remains unclear. In the present study, we aimed to explore the role of the lncRNA myocardial infarction-associated transcript (MIAT) in epithelial ovarian cancer tumorigenesis.Material and methodsQuantitative real-time PCR (qRT-PCR) was used to determine MIAT expression in human epithelial ovarian cancer tissues and cell lines, and the effects of MIAT on cell proliferation and cell apoptosis were determined by CCK-8 assay or flow cytometry analysis. Dual-Luciferase Reporter assay and Western blot assay were used to explore the molecular mechanisms of MIAT in epithelial ovarian cancer cells progression.ResultsOur data showed that the expression of lncRNA MIAT was remarkably increased in human epithelial ovarian cancer tissues and cell lines (p < 0.05). High MIAT expression was associated with poor overall survival of epithelial ovarian cancer patients (p < 0.05). Function assays showed that knockdown of MIAT expression significantly inhibited epithelial ovarian cancer cell proliferation and promoted cell apoptosis in vitro (p < 0.05). Moreover, we revealed that MIAT might function as an endogenous miR-330-5p sponge to regulate the target gene of miR-330-5p in epithelial ovarian cancer progression.ConclusionsLncRNA MIAT was found to be a tumor oncogenic lncRNA in epithelial ovarian cancer tumorigenesis. LncRNA MIAT promoted cell proliferation and inhibited cell apoptosis by negative regulation of miR-330-5p in epithelial ovarian cancer cells. Our findings suggested that MIAT might act as a candidate prognostic biomarker and new therapeutic target for treating epithelial ovarian cancer patients.

LncRNA PCGEM1 Induces Ovarian Carcinoma Tumorigenesis and Progression Through RhoA Pathway

Background/Aims: Prostate cancer gene expression marker 1 (PCGEM1) is a long noncoding RNA (lncRNA) and is well known as a promoter in prostate cancer and osteoarthritis synoviocytes. However, the role PCGEM1 plays in epithelial ovarian cancer is unknown. Methods: PCGEM1 expression was examined in epithelial ovarian cancer and normal ovarian tissues using reverse transcription–PCR. Ovarian cancer cell phenotypes and genotypes were examined after PCGEM1 overexpression or downregulation in vitro; besides, the effects of PCGEM1 overexpression was also examined in vivo. Results: PCGEM1 expression level was higher in epithelial ovarian cancer tissues than in normal ovarian tissues and was positively associated with differentiation (Well vs. Mod/Poor). Upregulation of PCGEM1 induced cancer cell proliferation, migration, and invasion, but decreased cell apoptosis through upregulating RhoA, YAP (Yes-associated protein), MMP2 (matrix metalloproteinase 2), Bcl-xL, and P70S6K expression; while PCGEM1 downregulation had the opposite effect. The nude mouse xenograft assay demonstrated that PCGEM1 overexpression promoted tumor growth. Furthermore, silencing RhoA expression reversed the effect of PCGEM1 and significantly inhibited RhoA, YAP, MMP2, Bcl-xL, and P70S6K protein expression. Conclusion: In conclusion, we suggest that PCGEM1 may be an inducer in epithelial ovarian cancer tumorigenesis and progression by upregulating RhoA and the subsequent expression of YAP, P70S6K, MMP2, and Bcl-xL.

Abstract POSTER-BIOL-1351: Molecular characterization of cyclin-dependent kinase 1 pathway in newly established epithelial ovarian cancer cell lines

Abstract Background: Epithelial ovarian cancer (EOC) is a heterogeneous gynecologic tumor. To better understand the biological pathways involved in the development of EOC, we performed mRNA expression profiling on newly established EOC cell lines. Methods: Five newly established EOC cell lines were characterized by transcript profiling. Microarray analyses were validated using quantitative real-time PCR (RT-PCT) and immunoblotting. Furthermore, biological networks of the differentially expressed genes were predicted using the STRING database and literature review. Results: A total of 239 genes represented by 24,957 probes were identified from microarray analysis, of which 98 and 141 genes are up- (&amp;gt; 2 fold, p &amp;lt; 0.05) or down-regulated (&amp;lt; 3 fold, p &amp;lt; 0.05), respectively, in EOC cell line compare to human ovarian surface epithelial cell lines. We identified a subset of EOC characterized by the numerous genes related to cell cycle and apoptosis, along with cyclin-dependent kinase 1 (CDK1). A total of 24 genes were validated by quantitative RT-PCR, and expressional reliabilities of 4 CDK1 pathway-related genes were confirmed by immunoblotting. Further biological network analysis revealed that the CDK1 pathway might be essential for EOC tumorigenesis. Conclusions: These data reveal that the CDK1 pathway is important to EOC development and progression, providing new insight into the biology of EOC. Citation Format: Wookyeom Yang, Hanbyoul Cho, Kim Sol, Jae-Hoon Kim. Molecular characterization of cyclin-dependent kinase 1 pathway in newly established epithelial ovarian cancer cell lines [abstract]. In: Proceedings of the 10th Biennial Ovarian Cancer Research Symposium; Sep 8-9, 2014; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2015;21(16 Suppl):Abstract nr POSTER-BIOL-1351.