Inhibition of the Aurora A kinase augments the anti-tumor efficacy of oncolytic measles virotherapy.

Oncolytic measles virus (MV) strains have demonstrated broad spectrum preclinical anti-tumor efficacy, including breast cancer. Aurora A kinase controls mitotic spindle formation and has a critical role in malignant transformation. We hypothesized that the Aurora A kinase inhibitor MLN8237 (alisertib) can increase MV oncolytic effect and efficacy by causing mitotic arrest. Alisertib enhanced MV oncolysis in vitro and significantly improved outcome in vivo against breast cancer xenografts. In a disseminated MDA-231-lu-P4 lung metastatic model, the MV/alisertib combination treatment markedly increased median survival to 82.5 days with 20% of the animals being long-term survivors versus 48 days median survival for the control animals. Similarly, in a pleural effusion model of advanced breast cancer, the MV/alisertib combination significantly improved outcome with a 74.5 day median survival versus the single agent groups (57 and 40 days, respectively). Increased viral gene expression and IL-24 upregulation were demonstrated, representing possible mechanisms for the observed increase in anti-tumor effect. Inhibiting Aurora A kinase with alisertib represents a novel approach to enhance MV-mediated oncolysis and antitumor effect. Both oncolytic MV strains and alisertib are currently tested in clinical trials, this study therefore provides the basis for translational applications of this combinatorial strategy in the treatment of patients with advanced breast cancer.

Measles Edmonston vaccine strain derivatives have potent oncolytic activity against osteosarcoma.

Osteosarcoma (OS) is the most common primary bone tumor affecting children and young adults, and development of metastatic disease is associated with poor prognosis. The purpose of this study was to evaluate the antitumor efficacy of virotherapy with engineered measles virus (MV) vaccine strains in the treatment of OS. Cell lines derived from pediatric patients with OS (HOS, MG63, 143B, KHOS-312H, U2-OS and SJSA1) were infected with MV expressing green fluorescent protein (MV-GFP) and MV-expressing sodium iodide symporter (MV-NIS) strains. Viral gene expression and cytotoxicity as defined by syncytial formation, cell death and eradication of cell monolayers were demonstrated. Findings were correlated with in vivo efficacy in subcutaneous, orthotopic (tibial bone) and lung metastatic OS xenografts treated with the MV derivative MV-NIS via the intratumoral or intravenous route. Following treatment, we observed decrease in tumor growth of subcutaneous xenografts (P=0.0374) and prolongation of survival in mice with orthotopic (P<0.0001) and pulmonary metastatic OS tumors (P=0.0207). Expression of the NIS transgene in MV-NIS infected tumors allowed for single photon emission computed tomography and positron emission tomography-computed tomography imaging of virus infected tumors in vivo. Our data support the translational potential of MV-based virotherapy approaches in the treatment of recurrent and metastatic OS.