Lipid domain in cancer cell plasma membrane shown by 1H NMR to be similar to a lipoprotein

Human blood lipoproteins have been characterised by 1H NMR methods and chemical analysis, and comparisons made with the properties of the triglyceride-rich plasma membrane domain found in cancer cells. By means of selective and non-selective T1 experiments, the lipids in HDL and LDL are shown to be in diffusive exchange. In contrast, the lipids of chylomicra and VLDL do not exhibit lipid diffusion, and therefore resemble the neutral lipids of cancer cell plasma membranes. 2D scalar correlated NMR (COSY) spectra of cancer cells or solid tumours are similar to those obtained from VLDL and LDL. The long T2 relaxation value observed for neutral lipid methylenes in metastatic cancer cells (greater than 300 ms) was not observed for any of the 4 lipoproteins studied. None of the lipoprotein classes gave a T2 longer than 250 ms.