Defining the mechanisms by which leptin stimulates proliferation of ovarian cancer cells

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 15017-15017
Author(s):  
A. B. Olawaiye ◽  
H. Sakamoto ◽  
T. Serikawa ◽  
A. Friel ◽  
R. Kiyama ◽  
...  

15017 Background: Ovarian cancer (OvCa) ranks fourth as the cause of death related to cancer in women in the U.S. The vast majority (>90%) of OvCa originates from the ovarian surface epithelium. There is sufficient evidence to suggest that hormones, especially estrogen, may be involved in the etiopathogenesis of epithelial OvCa. Recent studies indicate that leptin participates either directly or indirectly to promote carcinogenesis in both breast and endometrial cancers. Furthermore it has been proposed that leptin may elicit its action via an estrogen related pathway. Leptin can stimulate proliferation of some OvCa cell lines and has been implicated as a potential biomarker for OvCa. However the mechanism(s) by which leptin contributes to the growth of OvCa has yet to be defined. We hypothesize that leptin’s effect will be mediated in part by estrogen receptor (ER) pathways. Methods: Three epithelial OvCa cell lines (IGROV1, OVCAR5 and TOV21G) and one benign human ovarian surface epithelial cell line (HOSE) were evaluated. Enzyme linked immunosorbent assay (ELISA) and Western blotting were used to assess leptin and leptin receptor (ObR), respectively. Leptin (0.06 nM–6.25 nM) induced effects on cell proliferation were assessed in the presence or absence of an aromatase enzyme inhibitor (Anastrozole) or the ER antagonist (ICI182780). Further, we explored leptin-induced effects on ERα promoter activity as evidenced by change in fluorescence via a dual luciferase promoter reporter. All experiments were conducted in triplicate. All data were subjected to ANOVA followed by Tukey’s post hoc test (p < 0.05). Results: All ovarian cell lines expressed ObR; whereas, no measurable amounts of leptin were detected in conditioned media. Leptin stimulated cell proliferation in both the benign and malignant lines. Leptin-induced cell proliferation was inhibited by Anastrozole and ICI182780. Furthermore, leptin stimulated luciferase activity of the ERα promoter/reporter. Conclusions: Leptin promotes proliferation of benign and malignant ovarian epithelial cells and appears to be mediated, at least in part, via aromatase and ER which may have therapeutic implications. This work was supported by the Vincent Memorial Hospital, SG Komen Foundation and the Advanced Medical Research Foundation. No significant financial relationships to disclose.

2006 ◽  
Vol 13 (2) ◽  
pp. 641-651 ◽  
Author(s):  
Jung-Hye Choi ◽  
Kyung-Chul Choi ◽  
Nelly Auersperg ◽  
Peter C K Leung

Although gonadotropin-releasing hormone (GnRH) has been shown to play a role as an autocrine/ paracrine regulator of cell growth in ovarian surface epithelium and ovarian cancer, the factors which regulate the expression of GnRH and its receptor in these cells are not well characterized. In the present study, we employed real-time PCR to determine the potential regulatory effect of gonadotropins on the expression levels of GnRH I (the mammalian GnRH), GnRH II (a second form of GnRH) and their common receptor (GnRHR) in immortalized ovarian surface epithelial (IOSE-80 and IOSE-80PC) cells and ovarian cancer cell lines (A2780, BG-1, CaOV-3, OVCAR-3 and SKOV-3). The cells were treated with increasing concentrations (100 and 1000 ng/ml) of recombinant follicle-stimulating hormone (FSH) or luteinizing hormone (LH) for 24 h. Treatment with FSH or LH reduced GnRH II mRNA levels in both IOSE cell lines and in three out of five ovarian cancer cell lines (A2780, BG-1 and OVCAR-3). A significant decrease in GnRHR mRNA levels was observed in IOSE and ovarian cancer cells, except CaOV-3 cells, following treatment with FSH or LH. In contrast, treatment with either FSH or LH had no effect on GnRH I mRNA levels in these cells, suggesting that gonadotropins regulate the two forms of GnRH and its receptor differentially. In separate experiments, the effect of gonadotropins on the anti-proliferative action of GnRH I and GnRH II agonists in IOSE-80, OVCAR-3 and SKOV-3 cells was investigated. The cells were pretreated with FSH or LH (100 ng/ml) for 24 h after which they were treated with either GnRH I or GnRH II (100 ng/ml) for 2 days, and cell growth was assessed by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide] assay. Pretreatment of the cells with FSH or LH significantly reversed the growth inhibitory effect of GnRH I and GnRH II agonists in these cell types. These results provide the first demonstration of a potential interaction between gonadotropins and the GnRH system in the growth regulation of normal ovarian surface epithelium and its neoplastic counterparts.


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e22007-e22007
Author(s):  
Elizabeth Louise Dickson ◽  
Venugopal Thayanithy ◽  
Rachel Isaksson Vogel ◽  
Peter Argenta ◽  
Melissa Ann Geller ◽  
...  

e22007 Background: Preliminary evidence suggests that cell-to-cell communication may be responsible for the development of chemotherapy resistance in ovarian cancer. We propose tunneling nanotubes (TnTs) – long, thin actin-based cell extensions – as novel candidates to explain direct communication between treatment-refractory malignant ovarian cells. The purpose of this study was to investigate TnT formation between ovarian cancer cells in vitro. Methods: Using platinum-sensitive (A2780) and resistant (C200 and SKOV3, as well as ES2) ovarian cancer cell lines, we tested various conditions to assess factors affecting TnT formation. Scratch assays were utilized as a 2-dimensional simulation of ovarian cancer invasion. To assess TnTs as a conduit for transmission of therapeutic drugs between connected cells, we used doxorubicin, which auto-fluoresces in cell culture. Results: We determined that a hyperglycemic, low-serum, acidic medium stimulated TnT formation between all ovarian cancer cells studied, and more significantly, formed direct connections between A2780 to both C200 and SKOV3 cell lines. Conversely, Everolimus or Metformin decreased TnT formation in all cell lines with continuous exposure up to 96 hours; most prominently for the platinum-sensitive cell line. Time-lapse microscopy was used to assess chronologic formation of TnTs at the advancing front of the scratch wound. Cell proliferation assays were performed and confirmed the decrease in TnTs was not due to decreased cell proliferation. We directly observed fluorescing doxorubicin within the TnTs, suggesting TnTs act as a transport mechanism for cellular communication. Conclusions: TnT formation is stimulated in conditions of cellular stress similar to those experienced in vivo and results in direct connections between cells. Our data suggests that these conduits are a potential means of cellular exchange between platinum-sensitive and resistant ovarian cancer cells. Using currently available agents to target TnTs and disrupt this communication provides a novel approach to understanding and treating the problem of platinum resistance in ovarian cancer.


2016 ◽  
Vol 38 (5) ◽  
pp. 1915-1927 ◽  
Author(s):  
Peiquan Li ◽  
Yuxin Sun ◽  
Qing Liu

Aims: Aberrant expression of microRNA-340 (miR-340) has been frequently reported in some cancers excluding ovarian cancer (OC). The role and its molecular mechanism of miR-340 in OC have not been reported. Methods: Real-time PCR was performed to detect the expression of miR-340 in OC cell lines. MiR-340 mimic and negative control were transfected into OC cells and the effects of miR-340 on the cell proliferation, cell cycle, apoptosis and metastasis were investigated by Brdu-ELISA assay, flow cytometry, qRT-PCR, Transwell and ELISA assays. Furthermore, protein level of NF-κB1 was measured by Western blotting. Meanwhile, luciferase assays were performed to validate NF-κB1 as miR-340 target in OC cells. Results: In this study, we explored the effects of miR-340 overexpression on apoptosis, invasion and EMT in OC cells. The mRNA level of miR-340 in OC cell lines and tissues was evidently reduced. The miR-340 mimic was transiently transfected into OC cells using Lipofectamine™ 2000 reagent. Subsequently, the Brdu-ELISA results showed that introduction of miR-340 inhibited cell proliferation. Our data also demonstrated that miR-340 mimic arrested cell cycle progression and promoted apoptosis of OC cells. In addition, miR-340 overexpression could also inhibit invasion and EMT of OC cells. qRT-PCR were used to determined the expressions of matrix metalloproteinase-2 and -9 (MMP-2 and -9) in OC cells. Next, we found that NF-κB1 expression was evidently reduced by up-regulation of miR-340. Bioinformatics analysis predicted that the NF-κB1 was a potential target gene of miR-340. Luciferase reporter assay further confirmed that miR-340 could directly target the 3' UTR of NF-κB1. Moreover, overexpression of NF-κB1 in OC cells transfected with miR-340 mimic partially reversed the inhibitory of miR-340 mimic. Conclusion: miR-340 induced cell apoptosis and inhibited metastasis in OC cells by down-regulation of NF-κB1.


2009 ◽  
Vol 29 (17) ◽  
pp. 4766-4777 ◽  
Author(s):  
Callinice D. Capo-chichi ◽  
Kathy Q. Cai ◽  
Joseph R. Testa ◽  
Andrew K. Godwin ◽  
Xiang-Xi Xu

ABSTRACT A prominent hallmark of most human cancer is aneuploidy, which is a result of the chromosomal instability of cancer cells and is thought to contribute to the initiation and progression of most carcinomas. The developmentally regulated GATA6 transcription factor is commonly lost in ovarian cancer, and the loss of its expression is closely associated with neoplastic transformation of the ovarian surface epithelium. In the present study, we found that reduction of GATA6 expression with small interfering RNA (siRNA) in human ovarian surface epithelial cells resulted in deformation of the nuclear envelope, failure of cytokinesis, and formation of polyploid and aneuploid cells. We further discovered that loss of the nuclear envelope protein emerin may mediate the consequences of GATA6 suppression. The nuclear phenotypes were reproduced by direct suppression of emerin with siRNA. Thus, we conclude that diminished expression of GATA6 leads to a compromised nuclear envelope that is causal for polyploidy and aneuploidy in ovarian tumorigenesis. The loss of emerin may be the basis of nuclear morphological deformation and subsequently the cause of aneuploidy in ovarian cancer cells.


2021 ◽  
Author(s):  
Min Zhang ◽  
Yu Sun ◽  
Hanzi Xu ◽  
Yaqian Shi ◽  
Rong Shen ◽  
...  

Abstract Background: Circular RNAs are a class of non-coding regulatory RNAs reported to be involved in cancer development and progression. Previous studies, including our own, have indicated that hsa_circ_0007444 was downregulated in ovarian cancer (OC) tissues. Herein, we demonstrated another mechanism of hsa_circ_0007444 in ovarian cancer.Methods: The expression of hsa_circ_0007444, miR-23a-3p, and DICER1 were determined by quantitative real-time PCR. Cell proliferation, invasion, migration, and apoptosis were examined by cell counting kit 8, transwell, and flow cytometry assays. The roles of hsa_circ_0007444 in tumor growth and metastasis were assessed in vivo using a nude mouse xenograft model. The bioinformatics tools were employed to predict the binding sites, which were then verified by dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assays. DICER1 protein level was measured by western blot. Results: Hsa_circ_0007444 was downregulated in ovarian cancer cell lines compared with normal ovarian epithelial cell lines. Also, gain- and loss-of-function results indicated that hsa_circ_0007444 inhibited cell proliferation, invasion, migration, increased cell apoptosis of ovarian cancer cells in vitro, and impaired tumor growth and lung metastasis in vivo. Additionally, the results of the bioinformatics analysis, RIP, dual-luciferase reporter, and rescue assays confirmed that hsa_circ_0007444 could interact with AGO2 and sponge miR-23a-3p, thereby upregulating DICER1 expression, which was an important tumor suppressor in ovarian cancer.Conclusion: We found that overexpressed hsa_circ_0007444 could inhibit ovarian cancer progression through the hsa_circ_0007444/miR-23a-3p/DICER1 axis.


2009 ◽  
Vol 19 (9) ◽  
pp. 1564-1569 ◽  
Author(s):  
Siddharth G. Kamath ◽  
Ning Chen ◽  
Yin Xiong ◽  
Robert Wenham ◽  
Sachin Apte ◽  
...  

The discovery of more active therapeutic compounds is essential if the outcome for patients with advanced-stage epithelial ovarian cancer is to be improved. Gedunin, an extract of the neem tree, has been used as a natural remedy for centuries in Asia. Recently, gedunin has been shown to have potential in vitro antineoplastic properties; however, its effect on ovarian cancer cells is unknown. We evaluated the in vitro effect of gedunin on SKOV3, OVCAR4, and OVCAR8 ovarian cancer cell lines proliferation, alone and in the presence of cisplatin. Furthermore, we analyzed in vitro gedunin sensitivity data, integrated with genome-wide expression data from 54 cancer cell lines in an effort to identify genes and molecular pathways that underlie the mechanism of gedunin action. In vitro treatment of ovarian cancer cell lines with gedunin alone produced up to an 80% decrease in cell proliferation (P < 0.01) and, combining gedunin with cisplatin, demonstrated up to a 47% (P < 0.01) decrease in cell proliferation compared with cisplatin treatment alone. Bioinformatic analysis of integrated gedunin sensitivity and gene expression data identified 52 genes to be associated with gedunin sensitivity. These genes are involved in molecular functions related to cell cycle control, carcinogenesis, lipid metabolism, and molecular transportation. We conclude that gedunin has in vitro activity against ovarian cancer cells and, further, may enhance the antiproliferative effect of cisplatin. The molecular determinants of in vitro gedunin response are complex and may include modulation of cell survival and apoptosis pathways.


2021 ◽  
Vol 22 (8) ◽  
pp. 4243
Author(s):  
Karolina Wojtowicz ◽  
Karolina Sterzyńska ◽  
Monika Świerczewska ◽  
Michał Nowicki ◽  
Maciej Zabel ◽  
...  

Our goal was to examine the anticancer effects of piperine against the resistant human ovarian cancer cells and to explore the molecular mechanisms responsible for its anticancer effects. Our study used drug-sensitive ovarian cancer cell line W1 and its sublines resistant to paclitaxel (PAC) and topotecan (TOP). We analyzed the cytotoxic effect of piperine and cytostatic drugs using an MTT assay. The impact of piperine on protein expression was determined by immunofluorescence and Western blot. We also examined its effect on cell proliferation and migration. We noticed a different level of piperine resistance between cell lines. Piperine increases the cytotoxic effect of PAC and TOP in drug-resistant cells. We observed an increase in PTPRK expression correlated with decreased pTYR level after piperine treatment and downregulation of P-gp and BCRP expression. We also noted a decrease in COL3A1 and TGFBI expression in investigated cell lines and increased COL3A1 expression in media from W1PR2 cells. The expression of Ki67 protein and cell proliferation rate decreased after piperine treatment. Piperine markedly inhibited W1TR cell migration. Piperine can be considered a potential anticancer agent that can increase chemotherapy effectiveness in cancer patients.


Tumor Biology ◽  
2017 ◽  
Vol 39 (3) ◽  
pp. 101042831769454 ◽  
Author(s):  
Jialin Cheng ◽  
Min Su ◽  
Yunfeng Jin ◽  
Qinghua Xi ◽  
Yan Deng ◽  
...  

As a crucial member of the small ubiquitin-like modifier system, SUMO-specific protease 3, was identified to be essential for cell proliferation and ribosomal RNA processing. Recent studies showed that SUMO-specific protease 3 was elevated in ovarian cancer compared to normal tissue samples. However, the connection between SUMO-specific protease 3-specific expression and clinicopathological parameters of epithelial ovarian cancer, as well as the physiologically potential role of SUMO-specific protease 3 in epithelial ovarian cancer remained unclear. In this study, an analysis of 124 paraffin-embedded slices by immunohistochemistry indicated that SUMO-specific protease 3 expression was positively correlated with the International Federation of Gynecology and Obstetrics stages (p = 0.025), tumor grade (p = 0.004), and lymph node metastasis (p = 0.001) and was also a critical prognostic factor for the overall survival of epithelial ovarian cancer patients, as revealed by Kaplan–Meier curve analysis. Knockdown of SUMO-specific protease 3 weakened the proliferation, migration, and invasion capability of ovarian cancer cells, down-regulated the expression of Proliferating Cell Nuclear Antigen, Forkhead Box C2, and N-cadherin, and resulted in upregulation of p21 and E-cadherin. Consistent with our results, SUMO-specific protease 3 had been verified to promote cell proliferation, metastasis, and tumorigenesis in multiple malignant cancers, which was a redox-sensitive molecule mediating the epithelial–mesenchymal transition. Collectively, our findings for the first time specifically supported that SUMO-specific protease 3 might play an important role in the regulation of epithelial ovarian cancer progression and could serve as a potential biomarker for prognosis as well as provide a promising therapeutic target against epithelial ovarian cancer.


Endocrinology ◽  
2003 ◽  
Vol 144 (8) ◽  
pp. 3306-3314 ◽  
Author(s):  
Trevor G. Shepherd ◽  
Mark W. Nachtigal

Abstract Bone morphogenetic proteins (BMPs) are members of the TGFβ superfamily of cytokines that are involved in development, differentiation, and disease. In an analysis of normal ovarian surface epithelium (OSE) and ovarian cancer (OC) cells, we observed BMP4 mRNA expression and found that primary OC cells produce mature BMP4. In addition, each member of the downstream signaling pathway was expressed in primary OSE and OC cells. Smad1 was phosphorylated and underwent nuclear translocation in normal OSE and OC cells upon treatment with BMP4. Interestingly, the BMP target genes ID1 and ID3 were up-regulated 10- to 15-fold in primary OC cells, compared with a 2- to 3-fold increase in normal OSE. The growth of several primary OC cells was relatively unaltered by BMP4 treatment; however, long-term BMP4 treatment of primary OC cells resulted in decreased cell density as well as increased cell spreading and adherence. These data demonstrate the existence and putative function of BMP signaling in normal OSE and OC cells, and thus the continued examination of BMP4 signaling in the regulation of these two processes will be critical to further our current understanding of the role of BMP biology in OC pathogenesis.


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