Raman scattering studies of biochemical changes associated with carcinogenesis using tumorigenic and non-tumorigenic cells

Analysis of Raman spectra from a pair of tumorigenic and non-tumorigenic cells derived from rat embryo fibroblast (REF) cells will be presented. M1 cells are an immortalized but non-tumorigenic cell line made by stable transfection with the myc oncogene. MR1 cells are a tumorigenic line derived from MI cells by stable transfection with a mutated ras oncogene. Using these two cell lines, biochemical changes caused by tumorigenesis may be characterized without spectral interference from intercellular components, such as collagen, that may change as a result of tumorigenic transformation. We will present our current results from Raman studies covering spectroscopic differences between the two cell lines, sampling the cells in both the plateau and exponential phases of growth. Raman data from isolated nuclei of the two cell lines are also presented. Where possible, differences in the Raman spectra will be correlated with biochemical differences observed using other techniques. For example, changes in nucleic acid content, which can be monitored by flow cytometry, are also observed in the Raman spectra. Changes in the relative amounts of proteins, lipids, and nucleic acids are also determined. Such abilities will be important in distinguishing between tumorigenic and non-tumorigenic cells in vivo.