FTIR microspectroscopy defines early drug resistant human hepatocellular carcinoma (HepG2) cells

Characterization and identification of cancer cell, chemotherapy, resistance is important for both routine cancer therapy and trouble-shooting the medication treatment regimen. Present techniques for characterizing cancer cell resistance require multiple methods and steps, which are time-consuming and expensive. We present a protocol for simple sample handling, rapid detection, and spectral characterization of early resistant hepatocellular carcinoma (HepG2) cells, using Fourier transform infrared microspectroscopy (FTIR). Studies on alteration of the biochemical properties in a resistant HepG2 cell were evaluated-viz., increase efflux proteins (MRP-1 and P-gp) activity, total GSH content, anti-apoptotic (Bcl2) expression, and reduction of pro-apoptotic (Bax) proteins. Principle component analysis (PCA) was used to discriminate resistant HepG2 cells from parental HepG2 cells. Three important FTIR spectral regions were evaluated for reproducibility and discrimination ability-viz., lipid (3,000-2,800 cm(-1)), protein (1,700-1,500 cm(-1)) and carbohydrate and nucleic acid (1,300-900 cm(-1)). These 3 spectral regions can be used as spectroscopic biomarkers for differentiation of early or low resistance. This work presents a novel concept for high-throughput, FTIR spectroscopic discrimination of early resistance; thus enabling identification and characterization of cancer cell resistance.