Redox state changes of mitochondrial cytochromes in brain and breast cancers by Raman spectroscopy and imaging

This paper presents a non-invasive approach to study redox status of cytochromes in vitro human brain cells of normal astrocytes (NHA), astrocytoma (CRL-1718), glioblastoma (U87-MG) and medulloblastoma (Daoy), and human breast cells of normal cells (MCF10A), slightly malignant cells (MCF7) and highly aggressive cells (MDA-MB-231), in vivo animal models, and ex vivo brain and breast tissues surgically resected human specimens by means of Raman microspectroscopy at 355 nm, 532 nm, 785 nm and endospectroscopic Raman probe at 785 nm. Here we show that the amount of reduced cytochrome becomes abnormally high in human brain tumors and breast cancers. In contrast, the amount of reduced cytochrome c is lower in cancer cells when compared to the normal one at in vitro conditions when the effect of microenvironment is eliminated. Mitochondrial dysfunction and alterations in the chemical composition of the nucleus, mitochondria, lipid droplets, cytoplasm in single cells have been detected by Raman imaging. Incubation in vitro with retinoic acid increases the amount of reduced cytochrome c.