1H-MRS lipid signal modulation and morphological and ultrastructural changes related to tumor cell proliferation

Changes in signal intensity of (1)H-MRS mobile lipids, mostly triglycerides, have been observed in cultured HeLa cells during exponential growth. Signals were intense in the first days after seeding and almost disappeared after a few days in culture. Choline-based metabolites were not affected by growth. Treatment with the antitumor drug lonidamine, which blocks cell proliferation and cell progression through cycle, increased lipid signal intensity. Morphological changes in the organization of the cell surface were detected by scanning electron microscopy during exponential growth, and were confirmed by freeze fracture analysis. The observed metabolic and structural modifications during cell growth were correlated to cell cycle progression of HeLa cells, as high-intensity lipid signals were typical of cells with a high percentage of S- and( )G(2) + M-phases, while cells with a high frequency in G(1)-phase were characterized by mobile lipid signals of very low intensity. Magn Reson Med 42:248-257, 1999.