Accumulation of diacylglycerol in the liver membrane of the Long-Evans Cinnamon (LEC) rat with hepatitis: FT-IR spectroscopic and HPLC detection

Chemical mapping of tumor progression by FT-IR imaging: towards molecular histopathology

Fourier-transform infrared (FT-IR) spectro-imaging enables global analysis of samples, with resolution close to the cellular level. Recent studies have shown that FT-IR imaging enables determination of the biodistribution of several molecules of interest (carbohydrates, lipids, proteins) for tissue analysis without pre-analytical modification of the sample such as staining. Molecular structure information is also available from the same analysis, notably for protein secondary structure and fatty acyl chain peroxidation level. Thus, several cancer markers can be identified from FT-IR tissue images, enabling accurate discrimination between healthy and tumor areas. FT-IR imaging applications are now able to provide unique chemical and morphological information about tissue status. With the fast image acquisition provided by modern mid-infrared imaging systems, it is now envisaged to analyze cerebral tumor exereses in delays compatible with neurosurgery. Accordingly, we propose to take FT-IR imaging into consideration for the development of new molecular histopathology tools.

Can Fourier transform infrared spectroscopy at higher wavenumbers (mid IR) shed light on biomarkers for carcinogenesis in tissues?

Fourier transform infrared microspectroscopy (FTIR-MSP) has shown promise as a technique for detection of abnormal cell proliferation and premalignant conditions. In the present study, we investigate the absorbance in the sensitive wavenumber region between 2800 and 3000 cm(-1), which has been known to be due to the antisymmetric and symmetric stretching vibrations of CH2 and CH3 groups of proteins and lipids. We report common biomarkers from this region that distinguish between normal and malignant tissues and cell lines. Based on our findings, we propose that the wavenumber region around 2800 to 3000 cm(-1) in the FTIR spectra of cells and tissues could provide valuable scientific evidence at the onset of premalignancy and may be used for ex vivo and in vitro detection of carcinogenesis. To further examine the utility of these markers in cancer diagnosis and management, they are tested successfully in monitoring the changes occurring in leukemia patients during chemotherapy.

Chemoprevention of hepatocellular carcinoma: Use of tamoxifen in an animal model of hepatocarcinogenesis

Hepatocellular carcinoma (HCC) is common worldwide and growing in importance in the West. HCC often occurs against a background of liver disease, tends to present at an advanced stage, and has a poor prognosis, suggesting that it is an ideal target for chemoprevention. We sought to identify in an animal model chemopreventive agents for HCC that might be tested in human subjects. To this end, we induced liver tumors by injecting ethyl-nitrosourea in 6-week-old male B6C3F1 mice. Two chemopreventive agents were administered over a period of 60 weeks: tamoxifen (420 mg/kg feed) and a retinoid, 13-cis-retinoic acid (200 mg/kg feed). Animals were killed at 60 weeks and their livers examined for HCC and premalignant lesions. All liver lesions (altered foci, adenomata, HCC) occurred significantly less frequently in the tamoxifen-treated group than the group given only ethylnitrosourea (HCC developed in 2 of 47 (4%) vs 11 of 44 (25%); P < .001). On the other hand, retinoic acid appeared to increase the number of liver tumors, and in 2 animals angiosarcoma developed. Tamoxifen significantly decreased the incidence of chemical hepatocarcinogenesis in this model, suggesting an important role for estrogens in the pathogenesis of HCC and suggesting that it should be tested in human beings as a chemopreventive agent against HCC.