Partial least squares regression and fourier transform infrared (FTIR) microspectroscopy for prediction of resistance in hepatocellular carcinoma HepG2 cells.

We evaluated the feasibility of FTIR microspectroscopy combined with partial least squares regression (PLS-R) for determination of resistance in HepG2 cells. Cell viability testing was performed using neutral red assay for the concentration of cisplatin resulting in 50% antiproliferation (IC50). The resistance index (RI) is the ratio of the IC50 in resistant HepG2 cells vs. parental HepG2 cells. Principal component and unsupervised hierarchical cluster analyses were applied and a differentiation of samples of cells (parental, 1.8RI, 2.3RI, 3.0RI, and 3.5RI) was demonstrated (3000-2800cm-1 in the lipid and 1700-1500cm-1 in the protein regions. The FTIR spectra were preprocessed with several treatments to test the algorithm. PLS-R models were built using the 1170 spectra of the HepG2 cells. Cross-validation was used to evaluate prediction of the RI value using this model. PLS-R models-preprocessed with the second derivative FTIR spectra-yielded the best model (R2=0.99, RMSEE=0.095 and RPD=7.98). Most RI values were predicted with high accuracy (91-100%) such that the linear correlation between the actual and predicted RI values was nearly perfect (slope~1). FTIR microspectroscopy combined with chemometric analysis using PLS-R offers quick, accurate, and reliable quantitative analysis of HepG2 cell resistance.

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.

Induction of apoptosis in human hepatocellular carcinoma cells by extracts of Lannea coromandelica (Houtt.) Merr. and Diospyros castanea (Craib) Fletcher.

BACKGROUND: Herbal plants are a preferred source of anticancer agents. This study aims to screen the anticancer activity of a crude extract of twigs of (a) Bombax anceps Pierre var. anceps (BA); (b) Catunaregam tomentosa (Blume ex DC.) Tirveng. (CT); (c) Erythrophleum succirubrum Gagnep. (ES); (d) Lannea coromandelica (Houtt.) Merr. (LC); and (e) leaves and (f) twigs of Diospyros castanea (Craib) Fletcher (DC). METHODS: The 50 % ethanol-water extracts were prepared from each plant sample. In vitro anticancer effects of six extracts on the human hepatocellular carcinoma cell line (HepG2) in terms of cytotoxicity were investigated by neutral red assay, apoptosis induction by 4',6-diamidino-2-phenylindole (DAPI) staining, and DNA fragmentation by agarose gel electrophoresis. Normal Vero cells were tested for comparison and to determine cancer selectivity. Gas chromatography-mass spectrometry analysis was performed to identify the compounds in the extracts. RESULTS: The six crude extracts had different cytotoxicities and were classified into three groups based on their IC50 value and selectivity index (SI). DC (twig) crude extract had both a high cytotoxicity and SI toward HepG2 cells comparable to melphalan (P = 0.023). The crude extracts of DC (leaves), LC (twig), and BA (twig) had moderate cytotoxicity and a lower SI. Although all crude plant extracts induced apoptosis in more than 50 % of the DAPI-positive apoptotic HepG2 cells, only DC (twig) and LC (twig) showed laddering in the DNA fragmentation assay. 2-Palmitoylglycerol was the major compound common to both. Pyrogallol and lupeol were the major compounds in DC (twig) crude extract. Hexadecanoic acid and octadecenoic acid were the major compounds in LC (twig) crude extract, which had high toxicity but low selectivity. CONCLUSION: Ethanolic extracts from DC and LC twigs induced apoptosis in the HepG2 cell line. Pyrogallol and lupeol in DC (twig) might be responsible for the cytotoxicity toward the HepG2 cancer cells.