Differences in NMR spectra between tumor clones of defined metastatic potential

NMR can discriminate between malignant and normal tissues. This study attempts to determine if NMR can discriminate between tumor clones of differing metastatic potential derived from the same parent tumor. Rat 13762NF mammary adenocarcinoma clones of either high (MTLn3), intermediate (MTC), or low (MTPa) metastatic potential were grown in roller-bottle tissue culture, harvested during exponential growth phase, centrifuged to form a 0.75-cm3 pellet, and analyzed in a Varian 360L spectrometer operating at 60.0 MHz. Dimethyl sulfoxide (10%) was used as an internal standard at 3.1 ppm downfield from tetramethyl silane (TMS). NMR spectra of replicate samples were analyzed and compared. The position of the water peak for MTLn3 (n = 7) was 5.14 +/- 0.0301 vs 5.07 +/- 0.0207 for MTC (n = 5) and 5.05 +/- 0.009 for MTPa (n = 5) (P less than or equal to 0.001). Integrated area of upfield peaks (where glycoproteins residues are expected to resonate) was 47.43 +/- 7.17 for MTLn3 (n = 6) and 40.95 +/- 5.48 for MTC (n = 4) vs 32.06 +/- 10.1 for MTPa (n = 5) (P less than or equal to 0.05). Previous work with these tumor clones suggests quantitative changes in surface glycoproteins are associated with differences in metastatic behavior. This study demonstrates differences in water peaks between cells of high, intermediate, and low metastatic potential and differences in the integrated area of upfield spectral peaks. How these observations relate to the biologic properties of the cells is uncertain. If they prove to have general validity, NMR could be used to profile biologic potential of human malignancies.