PO-224 Fourier transform infrared spectroscopy-based detection of hypoxia-induced biomolecular changes in different cancer cell lines

Abstract

IntroductionOur previous studies have shown that under hypoxic stress human colorectal and breast cancer cells produce higher amounts of lipids compared to that under normoxic environment. The aim of this study was to estimate hypoxia induced cell metabolic response via the biochemical composition in prostate and lung cancer cells by using Fourier transform infrared spectroscopy (FTIR).Material and methodsLung cancer cell lines NCI-H69, COR-L23 and prostate cancer cell line PC3, and primary prostate cancer culture NFI-56 were seed in serum-free medium in density 1 × 106 per well in triplicates in 6-well plates and incubated for 48 in normoxic and hypoxic (5% CO2, 1% O2 and 94% N2) conditions. Cells were washed and snap frozen within 5 min after incubation. Hypoxic response in cells was verified by HIF1α expression in Western blot analysis. FTIR spectra of cancer cells were registered using HTS-XT microplate reader coupled with Vertex 70 (Bruker), and recorded in the frequency range of 4000–600 cm−1, with the spectral resolution of 4 cm−1 and 64 scans. Quantitative analysis of cell macromolecular composition was done as in (Grube et al. 2002). As characteristic absorption bands were used 1080 cm−1 for carbohydrates, 1250 cm−1 for nucleic acids, 1550 cm−1 for proteins and 2930 cm−1 for lipids.Results and discussionsResults showed differences in biochemical composition of prostate and lung cancer cells even under normoxic growth conditions. The carbohydrate content in NCI-H69 cells was 8.16% of dry weight (dw), in PC3 cells – 11.60% dw. The lipid content in NCI-H69 cells was 10.91% dw, but in PC3%–13.58% dw. The hypoxia induced metabolic response of prostate and lung cancer cells was more pronounced as an increase of lipid content – e.g., the lipid content in hypoxic cells of NCI-H69 was 13.29% dw, but in PC3%–15.91% dw. Thus, hypoxia induced lipid increase in lung cancer cells was for 22% but in prostate cancer cells for 17% compared to that in normoxic cells. These results are in line with our previous results and thus might represent universal mechanism and the observed total lipid content increase due to hypoxia could have a potential value for further studies of cancer cell lipid metabolism.ConclusionThe results of this study showed that under oxygen stress – starvation (hypoxia) the metabolism of lipids was much more affected than that of proteins, nucleic acids or carbohydrates suggesting that regulation of lipid synthesis can possibly provide advantages for cancer cell survival in extreme growth conditions.