Network Analysis Identifies an HSP90-Central Hub Susceptible in Ovarian Cancer

• Published in: Clinical cancer research 2013-09, Vol.19 (18), p.5053-5067
• Main Authors: HANQING LIU, FANG XIAO, CONNOLLY, Denise C, SEREBRIISKII, Ilya G, O'BRIEN, Shane W, MAGLATY, Marisa A, ASTSATUROV, Igor, LITWIN, Samuel, MARTIN, Lainie P, PROIA, David A, GOLEMIS, Erica A
• Format: Article
• Language: English
• Subjects: Animals; Antineoplastic agents; Antineoplastic Agents, Phytogenic - pharmacology; Apoptosis - drug effects; Biological and medical sciences; Blotting, Western; Cell Cycle - drug effects; Cell Proliferation - drug effects; Drug Synergism; Drug Therapy, Combination; Female; Female genital diseases; Flow Cytometry; Gene Regulatory Networks - drug effects; Gynecology. Andrology. Obstetrics; HSP90 Heat-Shock Proteins - antagonists & inhibitors; HSP90 Heat-Shock Proteins - genetics; HSP90 Heat-Shock Proteins - metabolism; Humans; Medical sciences; Mice; Mice, SCID; Mice, Transgenic; Multiple tumors. Solid tumors. Tumors in childhood (general aspects); Ovarian Neoplasms - drug therapy; Ovarian Neoplasms - genetics; Ovarian Neoplasms - metabolism; Paclitaxel - pharmacology; Pharmacology. Drug treatments; Protein Array Analysis; RNA, Small Interfering - genetics; Triazoles - pharmacology; Tumor Cells, Cultured; Tumors; Xenograft Model Antitumor Assays
• ISSN: 1078-0432; 1557-3265
• DOI: 10.1158/1078-0432.CCR-13-1115

Epithelial ovarian cancer (EOC) is usually detected at an advanced stage and is frequently lethal. Although many patients respond to initial surgery and standard chemotherapy consisting of a platinum-based agent and a taxane, most experience recurrence and eventually treatment-resistant disease. Although there have been numerous efforts to apply protein-targeted agents in EOC, these studies have so far documented little efficacy. Our goal was to identify broadly susceptible signaling proteins or pathways in EOC. As a new approach, we conducted data-mining meta-analyses integrating results from multiple siRNA screens to identify gene targets that showed significant inhibition of cell growth. On the basis of this meta-analysis, we established that many genes with such activity were clients of the protein chaperone HSP90. We therefore assessed ganetespib, a clinically promising second-generation small-molecule HSP90 inhibitor, for activity against EOC, both as a single agent and in combination with cytotoxic and targeted therapeutic agents. Ganetespib significantly reduced cell growth, induced cell-cycle arrest and apoptosis in vitro, inhibited growth of orthotopic xenografts and spontaneous ovarian tumors in transgenic mice in vivo, and inhibited expression and activation of numerous proteins linked to EOC progression. Importantly, paclitaxel significantly potentiated ganetespib activity in cultured cells and tumors. Moreover, combined treatment of cells with ganetespib and siRNAs or small molecules inhibiting genes identified in the meta-analysis in several cases resulted in enhanced activity. These results strongly support investigation of ganetespib, a single-targeted agent with effects on numerous proteins and pathways, in augmenting standard EOC therapies.