Abstract:
Chrysotherapeutics are under investigation as new or additional treatments for different types of
cancers. In this study, gold complexes were investigated for their anticancer potential using Raman
spectroscopy. The aim of the study was to determine whether Raman spectroscopy could be used
for the characterization of metallodrug-induced cell death. Symptoms of cell death such as
decreased peak intensities of proteins bonds and phosphodiester bonds found in deoxyribose
nucleic acids were evident in the principal component analysis of the spectra. Vibrational bands
around 761 cm 1 and 1300 cm 1 (tryptophan, ethanolamine group, and phosphatidylethanolamine)
and 1720 cm 1 (ester bonds associated with phospholipids) appeared in the Raman spectra of cervical
adenocarcinoma (HeLa) cells after metallodrug treatment. The significantly (p<0.05, one way
analysis of variance) increased intensity of phosphatidylethanolamine after metallodrug treatment
could be a molecular signature of induced apoptosis since both the co-regulated phosphatidylserine
and phosphatidylethanolamine are externalized during cell death. Treated cells had significantly
higher levels of glucose and glycogen vibrational peaks, indicative of a survival mechanism of cancer
cells under chemical stress. Cancer cells excrete chemotherapeutics to improve their chances of
survival and utilize glucose to achieve this. Raman spectroscopy was able to monitor a survival
strategy of cancer cells in the form of glucose uptake to alleviate chemical stress. Raman spectroscopy
was invaluable in obtaining molecular information generated by biomolecules affected by
anticancer metallodrug treatments and presents an alternative to less reproducible, conventional
biochemical assays for cytotoxicity analyses.
