The expression of vascular endothelial growth factor (VEGF) was assessed in osteosarcoma patient samples.
Twenty-six tissue samples from osteosarcoma patients were analyzed for VEGF protein expression by immunohistochemistry. VEGF-A mRNA transcript levels were examined by quantitative real-time PCR. Their relationship to clinical parameters and treatment outcome were analyzed.
Immunohistochemical staining for VEGF protein was positive in 81% of the samples (13 moderate, 8 strong). There were no differences in gender, frequency of metastasis at diagnosis and treatment outcomes according to VEGF protein expression. Strong staining for VEGF protein was related to poor response to preoperative chemotherapy (P=0.038) and male gender (P=0.035). VEGF-A mRNA was expressed in 85% of the samples but their transcript levels were not correlated with the gender (2.017 ± 2.379 for male and 3.992 ± 3.740 for female, P=0.212) or to the intensity of VEGF protein staining (P=0.293). Higher VEGF-A mRNA transcript level was related to poor response to preoperative chemotherapy (P=0.004), but not to the frequency of metastasis or gender.
From our preliminary study, expression of VEGF may play a role in response to chemotherapy of osteosarcoma. An expansion of the clinical correlative study is underway. Further studies are also underway to characterize the downstream pathways of VEGF-A in osteosarcoma patient tumor derived cell lines.
98th AACR Annual Meeting-- Apr 14-18, 2007; Los Angeles, CA