Abstract 142: SiRNA therapy against novel lncRNA NRCP: shutting down the fuel for cancer cells
Authors: Rupaimole Rajesha , Previs Rebecca , Lee Jaehyuk , Pradeep Sunila , Wu Sherry Y. , Ivan Cristina , Ferracin Manuela , Dennison Jennifer , Rodriguez-Aguayo Cristian , Calin George A. , Mills Gordon , Zhang Wei , Lopez-Berestein Gabriel , Bhattacharya Pratip , Sood Anil K. 
Published: August 2015

Long noncoding RNAs (lncRNAs) significantly influence the development and genomic regulation of cells. Even though several lncRNAs have been discovered using model systems such as yeast, few have been proven to be involved in cancer-specific phenotypes. In this study, we report the role of lncRNA NRCP in altering cancer cell metabolism and provide a strategy to target cancer metabolism using siRNAs. Methodology and Results: Using genomic profiling of ovarian tumors (n = 29) and normal ovarian tissues (n = 11) and comparative analyses, we found that NRCP was highly upregulated in ovarian tumors (&gt;100 fold, p&lt;0.05). In another cohort of 218 patients with high-grade serous ovarian cancer, NRCP expression in tumor tissues was negatively correlated with overall survival (p&lt;0.01), and the tumor tissues had significantly higher NRCP expression than the normal ovarian tissues or fallopian tube derived epithelial cells (&gt;6 fold, p&lt;0.01). Using siRNA mediated knockdown of NRCP in cancer cells and mRNA microarray, we carried out functional analyses. Upon performing Ingenuity Pathway Analysis of the significantly altered genes, we found that the cellular pathways most altered by siNRCP included glycolysis, cellular respiration, and glucose metabolism pathways. Significant decreases in glucose uptake and decreases in amount of lactate were observed in the cells treated with siNRCP compared with the control-treated cells. There was significant increase in basal respiration and ATP synthase dependent respiration in siNRCP- compared to control-treated cells. Analysis of global metabolite changes upon silencing NRCP, showed lactate as the key metabolite decreased compared to control siRNA treated cells (&gt;40%). Additionally, metabolites such as glutamate and acetate were also decreased significantly in NRCP silenced cells compared to siControl treated cells. NRCP knockdown in SKOV3 or A2780 ovarian cancer cells showed significantly increased apoptosis and decreased cell proliferation compared with control cancer cells.The cancer cells were more sensitive to cisplatin-mediated apoptosis in vitro after treatment with siNRCP plus cisplatin. In an orthotopic mouse model of ovarian cancer, siNRCP delivered via a liposomal carrier DOPC, significantly reduced tumor weight and number of distant metastatic nodules compared with control treatment (&gt;80%, p&lt;0.01). The mice treated with siNRCP showed enhanced cisplatin sensitivity in tumors when compared to mice treated with the control siRNA. More importantly, metabolite analysis of the in vivo samples revealed significant reduction in lactate levels in the tumors treated with siNRCP.

Significance: We report an unrecognized role of the lncRNA NRCP in modulating metabolism in ovarian cancer. DOPC nanoparticle-incorporated siRNA-mediated silencing of this lncRNA combined with cisplatin in vivo demonstrates the first known preclinical model indicating therapeutic potential of modulating lncRNAs in cancer.

Citation Format: Rajesha Rupaimole, Rebecca Previs, Jaehyuk Lee, Sunila Pradeep, Sherry Y. Wu, Cristina Ivan, Manuela Ferracin, Jennifer Dennison, Cristian Rodriguez-Aguayo, George A. Calin, Gordon Mills, Wei Zhang, Gabriel Lopez-Berestein, Pratip Bhattacharya, Anil K. Sood. SiRNA therapy against novel lncRNA NRCP: shutting down the fuel for cancer cells. [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 142. doi:10.1158/1538-7445.AM2015-142