Abstract 3271: Inhibition of angiogenesis and tumor growth by itraconazole in primary xenograft models of human non-small cell lung cancer
Authors: Aftab Blake T. , Dobromilskaya Irina , Hann Christine L. , Liu Jun O. , Rudin Charles M. 
Published: June 2012

Introduction: Lung cancer is the most common cause of cancer-related death in the US. Approximately 85 percent of cases are non-small cell lung cancer (NSCLC). Angiogenesis is a critical component to tumor growth. Bevacizumab is the only anti-angiogenic agent currently approved for NSCLC. Despite aggressive multimodality therapy, 5-year survival in patients with advanced stage NSCLC is exceedingly poor. Novel therapeutic strategies for NSCLC are critically needed.

The azole anti-fungal agent, itraconazole (ITRA) has been identified as a potential anti-angiogenic agent. In this study we further characterize the activity of ITRA in human umbilical vascular endothelial cell (HUVEC) based assays. Preclinical efficacy of ITRA is also examined as a single-agent and in combination with cisplatin in xenograft models of NSCLC generated with primary tumor tissue.

Methods: HUVECs were cultured in EGM-2 media (Lonza) and assayed in EGM-2 or EBM-2 media supplemented with recombinant growth factors, vascular endothelial growth factor (VEGF; 10 ng/ml), and basic fibroblast growth factor (bFGF; 12 ng/ml). Effects of ITRA on proliferation of HUVECs and three NSCLC cell lines, including H358 (bronchioalveolar carcinoma), H596 (adenosquamous carcinoma) and H1838 (adenocarcinoma) were evaluated by AqueousOne® (Promega). Additionally, HUVEC migration assays were carried out using an 8-micron pore Boyden chamber apparatus and endothelial tube formation assays were conducted using Geltrex® (Invitrogen) coated culture plates. To determine in vivo efficacy, mice bearing established xenografts derived from primary tumor tissue were treated orally with ITRA BID or QD at doses ranging from 75 to 100 mg/kg. In combination experiments, cisplatin (4 mg/kg) administered IP once weekly was given with ITRA. Mice were exposed to intravenous Hoechst 33342 prior to collection of tumors. Vascular area was determined by Hoechst 33342 and anti-CD31 staining. Tumor lysates were analyzed by immunoblot for Hif1α induction.

Results: ITRA demonstrates potent dose-dependent inhibition of HUVEC proliferation (IC50 &lt;0.7 μM). ITRA had no effect on proliferation in the panel of NSCLC cell lines tested (IC50 &lt;100 μM). ITRA inhibits HUVEC migration and tube formation with similar potency. In vivo, ITRA inhibits NSCLC tumor xenograft growth with maximum single-agent activity seen with 100 mg/kg BID treatment. Addition of ITRA to a cisplatin regimen significantly enhanced anti-tumor effects compared to either single-agent alone (p &lt;0.01). ITRA therapy resulted in increased tumor expression of HIF1α and significantly decreased tumor vascular area (p &lt;0.01).

Conclusion: The anti-angiogenic activity of ITRA and efficacy demonstrated in preclinical models of NSCLC supports development of this agent for the management of NSCLC in combination with standard of care chemotherapy.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3271. doi:10.1158/1538-7445.AM2011-3271