Raman micro-spectroscopic analysis of cultured HCT116 colon cancer cells in the presence of roscovitine.

Raman micro-spectroscopic analysis of cultured HCT116 colon cancer cells in the presence of roscovitine, [seliciclib, 2-(1-ethyl-2-hydroxy-ethylamino)-6-benzylamino-9-isopropylpurine], a promising drug candidate in cancer therapy, has been performed for the first time. The aim of this study was to investigate modulations in colon cancer cells induced by roscovitine. Raman spectra of the cultured HCT116 colon cancer cells treated with roscovitine at different concentrations (0, 5, 10, 25 and 50 µM) were recorded in the range 400-1850 cm(-1). It was shown that the second derivative profile of the experimental spectrum gives valuable information about the wavenumbers and band widths of the vibrational modes of cell components, and it eliminates the appearance of false peaks arising from incorrect baseline corrections. In samples containing roscovitine, significant spectral changes were observed in the intensities of characteristic protein and DNA bands, which indicate roscovitine-induced apoptosis. Roscovitine-induced apoptosis was also assessed by flow cytometry analysis, and analysis of propidium iodide staining. We observed some modifications in amide I and III bands, which arise from alterations in the secondary structure of cell proteins caused by the presence of roscovitine.

Evaluation of the effect of paclitaxel, epirubicin and tamoxifen by cell kinetics parameters in estrogen-receptor-positive ehrlich ascites tumor (eat) cells growing in vitro.

In this study the antiproliferative effects of Paclitaxel (PAC), Epirubicin (EPI) and Tamoxifen (TAM) on growth kinetics of Ehrlich Ascites Tumor (EAT) cells were examined in culture. An estrogen-receptor-positive ER (+) hyperdiploid EAT cell line growing in vitro was also analysed in the present study. IC50 doses of PAC, EPI and TAM (12 microg/ml, 12 microg/ml and 2 microg/ml, respectively) were used. Cells were treated with the above doses for 0, 4, 8, 16, 24 and 32 hrs. At the end of these periods, living cell numbers were determined by collecting EAT cells in every group for growth study rate and for MTT assay. Therefore, the mitotic index was determined in the same experimental groups. The proliferation of EAT cells, inhibited by PAC, EPI and TAM concentrations was compared to control with increasing treatment time (4-32 hrs). Treatment of PAC, EPI and TAM alone for 24 hrs decreased the proliferation rate of EAT cells by 50% with respect to control. The inhibition of proliferation rate was higher in double drug treatment than that in single drug treatment with increased treatment time. In the treatment of three drugs applied for 32 hrs, this effect reached a maximum and proliferation rate decreased by 12% as compared to the (100%) control. In our studies, when the mitotic index parameter data were evaluated to determine which phase of the cell cycle was affected by PAC to cause the repression of cell reproduction, it was found that PAC exerted of its cytotoxic effect by causing cell accumulation at mitosis. The accumulation of the cells resulted in an increase in mitotic index values, which was an expected consequence of PAC treatment. It was observed that depending on the drug treatments, inhibition of proliferation rate and mitotic index in EAT cells were increased with respect to control, being with statistically significant occurrence (p < 0.01 - p < 0.001). As a result, concomitant treatment combined with hormonal therapy has given improved results compared with single treatment and PAC + EPI + TAM treatments had a maximum synergistic effect for 32 hrs (p < 0.001).