QUANTITATIVE NMR MICROSCOPY OF MULTICELLULAR TUMOR SPHEROIDS AND CONFRONTATION CULTURES

In cancer research, tumor spheroids are a well established system to s tudy tumor metabolism resembling the situation in vivo more closely ce ll monolayers. Spherical aggregates of malignant melanoma cells (MV3) and their invasion into rat brain aggregates have been investigated by quantitative NMR microscopy, Relaxation times (T-1, T-2) and diffusio n parameter images were acquired with an in-plane resolution of 14 x 1 4 mu m(2) The authors were able to demonstrate that the morphology of the spheroids can be visualized on these NMR maps, The contrast was ma inly manifested in relaxation maps, where average relaxation times T-1 = 1.94 +/- 0.17 s and T-2 = 42.8 +/- 6.3 ms were obtained for prolife rating cells, and T-1 = 2.49 +/- 0.31 s and T-2 = 104.3 +/- 29.4 ms fo r the necrobiotic center, The mean diffusion coefficients were 0.59 +/ - 0.12 mu m(2)/ms and 0.85 +/- 0.14 mu m(2)/ms, respectively, The auth ors could follow the dynamic process of tumor cell invasion in the inv estigated co-culture system, Knowledge about tumor cell migration and tumor cell invasion is essential for the understanding of cancer and i ts therapy, Quantitative NMR microscopy can study this dynamic process noninvasively and therefore may help to assess the influence of thera py on the micromilieu of these spheroids.