A novel approach for the discrimination of culture medium from Vascular Endothelial Growth Factor (VEGF) overexpressing colorectal cancer cells

Abstract

Objectives: The expression level of Vascular Endothelial Growth Factor (VEGF) is assumed as a prognostic marker for several tumor types, including colorectal cancer. Therefore, the determination of pre- and post-therapy levels of VEGF appears to have great value in the assessment of tumor prognosis. Enzyme-Linked Immunosorbent Assay (ELISA) is commonly used for the determination of serum or plasma VEGF levels, but the method is costly and time-consuming. In this study,we aimed to describe a rapid and cost-effective analysis method to discriminate VEGF overexpressing colorectal cancer-derived conditioned medium (CM). Methods: Attenuated Total Reflection (ATR)-Fourier Transform Infrared (FTIR) spectroscopy, combined with Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), was used to differentiate VEGF overexpressing colorectal cancer cell line CM from CM obtained from the corresponding control cells which express and secrete relatively lower amount of VEGF. Results: Samples belong to VEGF overexpressing colorectal cancer cells were clearly distinguished from the control group with very high PC scores as PC1 + PC2 = 96%. Besides, a 100% accurate distinction between these two groups was achieved by the LDA analysis. Conclusions: ATR-FTIR spectroscopy combined with pattern recognition techniques was able to discriminate CM of VEGF overexpressing colorectal cancer cells with high efficiency and accuracy.