Infrared spectroscopy of human bone marrow: evidence of structural changes during acute leukemia
Fourier transform infrared (FTIR) spectroscopy was explored as a means to distinguish newly diagnosed of acute lymphoblastic leukemia from disease free bone marrow samples. Characteristic bands alterations were identified in both healthy and diseased samples arising from cellular protein, lipid and DNA. There were specific changes that affected the secondary structure of proteins that appeared in the FTIR spectra and confirmed with the second derivative analysis. The overall protein structure in the control sample consists primarily of α-helix, whereas in ALL sample it has a relatively high proportion of anti-parallel β-sheet protein constituents presumably due to leukemia. Different absorbance's ratios for specific bands were calculated and plotted versus the patient samples. There are significant fluctuations in the ratios under investigation which can be attributed to the changes in the biomolecular structure between normal and leukemia samples. Our results indicate that the absorbance of amide A and B are in the range 3,340-3,000, the lipid/protein ratio and the phosphate/amide II ratio are all yielding statistically significant differences parameters, that it can be used as a biomarker in differentiating acute leukemia from leukemia free bone marrow.
Keywords: FTIR spectroscopy, acute lymphoblastic leukaemia, human bone marrow, structural changes, quantitative analysis, infrared spectroscopy, biomolecular structure, biomarkers