Characterization of an oncolytic adenovirus vector constructed to target the cMet receptor

Abstract

The cMet receptor is a homodimer with tyrosine kinase activity. Upon stimulation with its ligand, hepatocyte growth factor (HGF), the receptor mediates wide physiologic actions. The HGF-cMet signaling pathway is dysregulated in many cancers, which makes cMet an important target for novel therapeutic interventions. Oncolytic adenoviruses (Ads) have been used for the past three decades as a promising therapeutic approach for a wide array of neoplastic diseases. To date, achieving cancer-specific replication of oncolytic Ads has been accomplished by either viral genome deletions or by incorporating tumor selective promoters. To achieve novel specificity of oncolytic Ad infection of cancer cells that overexpress cMet, we inserted the HGF NK2 sequence, corresponding to a competitive antagonist of HGF binding to the cMet receptor, into the Ad serotype 5 (Ad5) fiber gene. The resulting vector, Ad5-pIX-RFP-FF/NK2, was rescued, amplified in HEK293 cells, and characterized. Binding specificity and viral infectivity were tested in various cancer cell lines that express varying levels of cMet and hCAR (the Ad5 receptor). We found that Ad5-pIX-RFP-FF/NK2 demonstrated binding specificity to the cMet receptor. In addition, there was enhanced viral infectivity and virus replication compared with a non-targeted Ad vector. Although NK2 weakly induces cMet receptor activation, our results showed no receptor phosphorylation in the context of an oncolytic Ad virus. In summary, these results suggest that an oncolytic Ad retargeted to the cMet receptor is a promising vector for developing a novel cancer therapeutic agent.

CXCL12 Retargeting of an Oncolytic Adenovirus Vector to the Chemokine CXCR4 and CXCR7 Receptors in Breast Cancer

“…We previously utilized the T4 fibritin platform to successfully retarget an oncolytic adenovirus to the cMet receptor in hepatocellular carcinoma and breast cancer [48]. Ad5 binding is mediated by the CXADR receptor, and entry is facilitated in a two-step uptake mechanism by the αvβ3 and αvβ5 integrins as well as other integrins that recognize Arg-Gly-Asp (RGD) motif that is expressed on the penton base protein [49].…”

Oncolytic Virotherapy for Breast Cancer Treatment

“…For example, AdLuc(HRG-fiber) containing the Heregulin (HRG) ligand in the HI loop of the Ad knob domain successfully retargeted the virus to the receptor tyrosine-protein kinase erbB-3 (HER3) in breast cancer cells [ 22 ]. Another oAd, Ad5-pIX-RFP-FF/NK2, retargeted the oAd to the tyrosine kinase receptor Met (cMet), which was found to be overexpressed in a variety of cancers, including breast cancer [ 23 , 24 ]. In addition, chimeric Ads using alternative serotypes, such as the…”

A dual MET/AXL small‐molecule inhibitor exerts efficacy against gastric carcinoma through killing cancer cells as well as modulating tumor microenvironment

“… 14 MET activation induces multiple signaling cascades associated with cell proliferation, migration, invasion, survival, and branching morphogenesis. 15 , 16 , 17 Dysregulation of the HGF/MET signaling axis has been described in a variety of malignant and premalignant lesions, including lung cancer, gastroesophageal cancer, hepatocellular carcinoma, breast cancer, ovarian cancer, multiple myeloma, and colorectal cancer 18 , 19 , 20 , 21 , 22 , 23 , 24 and is associated with tumor growth, angiogenesis, invasion, and metastasis. 25 , 26 MET gene amplification has been reported in approximately 8% of patients with gastric cancer by fluorescence in situ hybridization (FISH) analysis, 8 , 27 , 28 , 29 while polymerase chain reaction (PCR)‐based assays showed that the occurrence of MET gene copy number increases to approximately 20%.…”