Naslov
Attenuated Total Reflectance - Fourier Transform Infrared spectroscopy (ATR-FTIR) reveales increased cholesterol esters in drug resistant laryngeal carcinoma cells

Autori
Osmak, Maja ; Rak, Sanjica ; De Zan, Tihana ; Gamulin, Ozren ; Kosović, Marin

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
European Journal of Cancer 48, Supplement 5 / Eggermont, Alexander M.M. (editor in chief) - Oxford : Elsevier, 2012, S26-S26

Skup
22nd Biennial Copngres of the European Association for Cancer Research

Mjesto i datum
Barcelona, Španjolska, 07.07.2012. - 10.07.2012

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
FTIR; Tumor; Drug resistance; Cholosterol ester

Sažetak
Background Infrared spectroscopy is developing as a new and more holistic approach to studying drug resistance, yielding a unique fingerprint of all molecules present in the cell. In our laboratory we have developed a human laryngeal carcinoma (HEp-2) subline resistant to carboplatin (7T cells) and cross resistant to the natural compound curcumin. In our previous work we have reported that following treatment with curcumin, 7T cells exhibited reduced accumulation of curcumin, induction of reactive oxidative species (ROS) and Hsp70 expression, as well as diminished lipid peroxidation, oxidative and basic DNA damage, G2/M phase arrest, and the induction of apoptosis, as compared to parental HEp2 cells. In order to shed more light on the molecular mechanism of curcumin resistance in 7T cells, we used FTIR-ATR spectroscopy. Materials and methods HEp-2 and 7T cells were independently grown and samples were collected 20 times. The infrared spectra of both, HEp-2 and 7T exponentially growing cells were recorded with the FTIR Perkin–Elmer GX spectrometer. 5x105 cells in 20 L NS solution per sample were placed on the surface of HATR ZnSe crystal , and dried with N2 flux. 20 independent ATR-FTIR spectra for each cell line were recorded and used for ATR-FTIR spectral analysis. Cell spectra were obtained in the 4000-480 cm-1 region, 200 scans and at a resolution with 4 cm-1 at room temperature. The data analysis was carried out using the MATLAB program with two add-ons, PLS_Toolbox and Kinetics. Results and discussion By comparing the spectra from parental HEp-2 and resistant 7T subline, we found that the most interesting difference was the increase in cholesterol ester content recorded in resistant 7T cells. According to the literature, cholesterol esters are localized in lipid droplets inside cells. Using the Oil Red O dye we confirmed the existence of lipid droplets in resistant 7T cells and also that their quantity and presence in the cell culture is serum dependent. However, almost none of these properties were found in HEp-2 cells. Conclusion We can conclude that in addition to previous determined molecular mechanisms involved in resistance of 7T cells to curcumin, these cells exhibit increased content of cholesterol esters suggesting an alteration in their cellular metabolism. In addition, our results clearly show the advantages of FTIR-ATR spectroscopy as a new technique in cellular or molecular biology research.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Biologija

POVEZANOST RADA