Characterization of brivanib therapy response in hepatocellular carcinoma xenografts using 1H HR-MAS spectroscopy and histopathology

Angiogenesis inhibition is an attractive therapeutic strategy in the management of solid tumors. Vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF) are key factors in growth and neovascularization of hepatocellular carcinoma (HCC). Brivanib is a novel, orally available dual tyrosine kinase inhibitor that selectively targets the key angiogenesis receptors VEGF-R2, FGF-R1 and FGF-R2. Recently, high-resolution magic angle spinning magnetic resonance spectroscopy (HR-MAS MRS) has provided the opportunity to investigate more detailed metabolic profiles from intact tissue specimens that are correlated with histopathology and is thus, a promising tool for monitoring changes induced by treatment. In the present study, 1H HR-MAS MRS and immunohistochemistry were used to investigate the antitumor efficacy of brivanib in HCC xenograft models. Tumor growth was significantly suppressed in brivanib-treated mice compared with the controls and treatment was associated with the inhibition of angiogenesis, increased apoptosis and inhibition of cell proliferation. Furthermore, HR-MAS techniques showed altered metabolic profiles between the two groups. HR-MAS spectra demonstrated a significant decrease in choline metabolite levels in the treated groups, concurrent with decreased cell proliferation and increased apoptosis. The results showed that 1H HR-MAS MRS provides quantitative metabolite information that may be used to analyze the efficacy of brivanib treatment in Hep3B tumor xenografts. Thus, the HR-MAS MRS technique may be a complementary method to support histopathological results and increase its potential for use in the clinic.