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Preclinical data supporting the flavone baicalein as a novel mTOR inhibitor with potent activity against endometrial cancer cells
either alone or in combination with chemotherapy. Chou-Talalay method was used to assess synergy between ruxolitinib and other anticancer agents. The in vivo antitumor activity of ruxolitinib was evaluated in mice bearing peritoneal OVCAR8-ip human ovarian cancer cells. This cell line was derived from OVCAR8 human ovarian cancer cells by selecting for a peritoneal metastatic phenotype in the mice. Comparisons between 2 groups were determined with the Student t test. P b .05 was considered statistically significant. Results: Ruxolitinib was found to effectively inhibit the phosphorylation of STAT3 in OVCAR8, SKOV3, and MDAH2774 cells, and reduced cell viability with IC50 value in the range of 10 to 17 mM in these cells. In addition, ruxolitinib synergistically increased antitumor activity of cisplatin, carboplatin, paclitaxel, doxorubicin, and topotecan. The IC50 of these anticancer agents decreased two- to threefolds in the presence of ruxolitinib. Finally, ruxolitinib reduced the tumor burden of OVCAR8 in a peritoneal ovarian cancer mouse model when these mice were treated with ruxolitinib by oral gavage at 60 mg/kg twice a day. Conclusions: Our results demonstrate that ruxolitinib inhibits activation of STAT3, reduces cell viability, enhances sensitivity of ovarian cancer cells to other anticancer agents, and suppresses ovarian tumor growth in mice. These results may provide a foundation for clinical investigation of ruxolitinib in ovarian cancer patients.
Fig. 1.
doi:10.1016/j.ygyno.2016.04.140
109 - Featured Poster Session Micro-RNAs associated with ovarian cancer in vitro cisplatin resistance regulate epithelial-mesenchymal transition B.M. Boaca, Y. Xionga, D. Marchiona, F. Abbasia, B.R. Khulpateeab, C. McClunga, S.E. Robertsonc, J.M. Lancastera, A. Maglioccoa. aH. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA, bThe Women's Institute for Gynecologic Cancer and Special Pelvic Surgery, Tampa, FL, USA, cMoffitt Cancer Center, University of South Florida, Tampa, FL, USA
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doi:10.1016/j.ygyno.2016.04.139
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Abstracts / Gynecologic Oncology 141 (2016) 2–208
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108 - Featured Poster Session Preclinical data supporting the flavone baicalein as a novel mTOR inhibitor with potent activity against endometrial cancer cells E.S. Han, Q. Xing, J. Yan, W. Wen, T. Dellinger, M.T. Wakabayashi, J.H. Yim. City of Hope, Duarte, CA, USA
Objectives: The central role of micro-RNAs (miRNAs) in biologic processes make them appealing candidates as cancer biomarkers and therapeutic targets. We sought to define the miRNAs associated with the development of ovarian cancer (OVCA) in vitro cisplatin resistance and the biologic processes they regulate. Methods: Serial OVCA cell cisplatin treatments were performed in parallel with measurements of miRNA expression changes. Pearson correlation was used to identify miRNA with expression that correlated with increasing cisplatin resistance (IC50). The MiRanda database was used to identify predicted target genes of miRNAs associated with cisplatin resistance. GeneGo Metacore analysis identified the representation of molecular signaling pathways associated with the differentially expressed genes. Results: Correlation analysis identified 9 miRNAs that were significantly (P b 0.01) associated with the IC50of 4 OVCA cell lines with acquired resistance to cisplatin: miR-496, miR-485-5p, let-7g, miR-152 (positive correlation), and miR-422b, miR-17-3p, miR520h, miR-27b, and miR-432* (negative correlation). Target gene information was available for 5 of 9 cisplatin resistance–associated miRNA. Metacore analysis identified 15 molecular signaling pathways (FDR b 0.05) common to 3 or more of the resistance-associated miRNAs. Eleven of 15 signaling pathways are involved in epithelialmesenchymal transition (EMT). Conclusions: miRNAs associated with the evolution of OVCA in vitro cisplatin resistance regulate the expression of genes and signaling pathways involved in EMT. Our data suggest that EMT processes influence the development of chemoresistance and may provide a new avenue for therapeutic intervention.
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Objectives: The mTOR pathway is a promising target for endometrial cancer therapy commonly because of the loss of PTEN expression. Metformin has been shown to inhibit endometrial cancer cell proliferation and is currently in phase II/III clinical trial testing. We have identified a natural flavone, baicalein, which markedly upregulates DNA Damage Induced Transcript 4 (DDIT4), suppresses breast and ovarian cancer cell growth, and alters mTOR pathway. We examined the activity of baicalein in endometrial cancer cells. Methods: The endometrial cancer cell line HEC1a was treated with baicalein (5–80 μM) or metformin (5–10,000 μM) and growth was assessed at 24 to 72 hours with the MTT assay. Total protein lysates were obtained for Western blot analysis to evaluate mTOR pathway mediators and DDIT4 levels. In vivo studies were performed with an HEC1a mouse model. Mice received either control or baicalein (80 mg/kg) treatment by oral gavage daily. Tumor volumes were measured over time. Results: Baicalein inhibited growth of HEC1a cell line in a dosedependent fashion (IC50 ~ 10 μM). In contrast, higher millimolar concentrations (N1,000-fold) were required to inhibit growth with metformin. The observed growth inhibition with baicalein was associated with decreased PS6K1 and PS6 levels and increased DDIT4 levels. We tested baicalein (80 mg/kg) in an endometrial cancer cell mouse model. We observed significant tumor growth inhibition in the HEC1A mouse model compared with control mice. (See Fig. 1.) Conclusions: Both in vitro and in vivo studies support baicalein as a potent inhibitor of endometrial cancer cell proliferation. The inhibitory effect correlates with mTOR pathway inhibition and increase in DDIT4 expression. This preclinical study supports the use of baicalein as a novel treatment for endometrial cancer.
doi:10.1016/j.ygyno.2016.04.141
Fig. 1.
doi:10.1016/j.ygyno.2016.04.140
109 - Featured Poster Session Micro-RNAs associated with ovarian cancer in vitro cisplatin resistance regulate epithelial-mesenchymal transition B.M. Boaca, Y. Xionga, D. Marchiona, F. Abbasia, B.R. Khulpateeab, C. McClunga, S.E. Robertsonc, J.M. Lancastera, A. Maglioccoa. aH. Lee Moffitt Cancer Center & Research Institute, Tampa, FL, USA, bThe Women's Institute for Gynecologic Cancer and Special Pelvic Surgery, Tampa, FL, USA, cMoffitt Cancer Center, University of South Florida, Tampa, FL, USA
DP
doi:10.1016/j.ygyno.2016.04.139
OF
Abstracts / Gynecologic Oncology 141 (2016) 2–208
RO
46
TE
108 - Featured Poster Session Preclinical data supporting the flavone baicalein as a novel mTOR inhibitor with potent activity against endometrial cancer cells E.S. Han, Q. Xing, J. Yan, W. Wen, T. Dellinger, M.T. Wakabayashi, J.H. Yim. City of Hope, Duarte, CA, USA
Objectives: The central role of micro-RNAs (miRNAs) in biologic processes make them appealing candidates as cancer biomarkers and therapeutic targets. We sought to define the miRNAs associated with the development of ovarian cancer (OVCA) in vitro cisplatin resistance and the biologic processes they regulate. Methods: Serial OVCA cell cisplatin treatments were performed in parallel with measurements of miRNA expression changes. Pearson correlation was used to identify miRNA with expression that correlated with increasing cisplatin resistance (IC50). The MiRanda database was used to identify predicted target genes of miRNAs associated with cisplatin resistance. GeneGo Metacore analysis identified the representation of molecular signaling pathways associated with the differentially expressed genes. Results: Correlation analysis identified 9 miRNAs that were significantly (P b 0.01) associated with the IC50of 4 OVCA cell lines with acquired resistance to cisplatin: miR-496, miR-485-5p, let-7g, miR-152 (positive correlation), and miR-422b, miR-17-3p, miR520h, miR-27b, and miR-432* (negative correlation). Target gene information was available for 5 of 9 cisplatin resistance–associated miRNA. Metacore analysis identified 15 molecular signaling pathways (FDR b 0.05) common to 3 or more of the resistance-associated miRNAs. Eleven of 15 signaling pathways are involved in epithelialmesenchymal transition (EMT). Conclusions: miRNAs associated with the evolution of OVCA in vitro cisplatin resistance regulate the expression of genes and signaling pathways involved in EMT. Our data suggest that EMT processes influence the development of chemoresistance and may provide a new avenue for therapeutic intervention.
UN
CO
RR
EC
Objectives: The mTOR pathway is a promising target for endometrial cancer therapy commonly because of the loss of PTEN expression. Metformin has been shown to inhibit endometrial cancer cell proliferation and is currently in phase II/III clinical trial testing. We have identified a natural flavone, baicalein, which markedly upregulates DNA Damage Induced Transcript 4 (DDIT4), suppresses breast and ovarian cancer cell growth, and alters mTOR pathway. We examined the activity of baicalein in endometrial cancer cells. Methods: The endometrial cancer cell line HEC1a was treated with baicalein (5–80 μM) or metformin (5–10,000 μM) and growth was assessed at 24 to 72 hours with the MTT assay. Total protein lysates were obtained for Western blot analysis to evaluate mTOR pathway mediators and DDIT4 levels. In vivo studies were performed with an HEC1a mouse model. Mice received either control or baicalein (80 mg/kg) treatment by oral gavage daily. Tumor volumes were measured over time. Results: Baicalein inhibited growth of HEC1a cell line in a dosedependent fashion (IC50 ~ 10 μM). In contrast, higher millimolar concentrations (N1,000-fold) were required to inhibit growth with metformin. The observed growth inhibition with baicalein was associated with decreased PS6K1 and PS6 levels and increased DDIT4 levels. We tested baicalein (80 mg/kg) in an endometrial cancer cell mouse model. We observed significant tumor growth inhibition in the HEC1A mouse model compared with control mice. (See Fig. 1.) Conclusions: Both in vitro and in vivo studies support baicalein as a potent inhibitor of endometrial cancer cell proliferation. The inhibitory effect correlates with mTOR pathway inhibition and increase in DDIT4 expression. This preclinical study supports the use of baicalein as a novel treatment for endometrial cancer.
doi:10.1016/j.ygyno.2016.04.141