In situ immunocytochemical detection of altered membrane composition induced by cell-cell contact in cultured mammalian cells.

In cultured mammalian cells, both normal and transformed, cell-cell contact was shown to alter the detergent extractability of nuclear and plasma membranes detected using immunocytochemistry of fixed cells. This alteration occurred in each cell individually, occurred in less than 1 hour after altered cell-cell contact, and did not involve new protein or mRNA synthesis. These results indicate that composition of cellular membranes is highly affected by cell-cell contact and culture density.

A method for profiling gangliosides in animal tissues using electrospray ionization-tandem mass spectrometry.

Gangliosides are critical in many functions of mammalian cells but present as a minor lipid component with many molecular species of subtle differences. Conventional strategies for profiling gangliosides suffer from poor reproducibility, low sensitivity, and low-throughput capacity. Prior separation of gangliosides by thin-layer chromatography and/or high-performance liquid chromatography not only was laborious and tedious but also could introduce uneven losses of molecular species.

Overexpression of PEMT2 downregulates the PI3K/Akt signaling pathway in rat hepatoma cells.

Phosphatidylethanolamine N-methyltransferase 2 (PEMT2) is an isoform of PEMT that converts phosphatidylethanolamine to phosphatidylcholine in mammalian liver. Overexpression of PEMT2 led to inhibition of proliferation of hepatoma cells [J. Biol.