Transport characteristics of tryptanthrin and its inhibitory effect on P-gp and MRP2 in Caco-2 cells.

PURPOSE. Tryptanthrin, an indole quinazoline alkaloid with multiple medical activities, has been recently under preclinical development as an anti-tuberculosis and anti-tumor drug. The aims of this study are to characterize the intestinal transport of tryptanthrin in Caco-2 cells, to determine whether P-glycoprotein (P-gp) and multidrug resistance-associated protein 2 (MRP2) are involved in this issue, and to evaluate the potential influence of tryptanthrin on the function of P-gp and MRP2.

The effect of sphingomyelin synthase 2 (SMS2) deficiency on the expression of drug transporters in mouse brain.

Sphingomyelin synthase (SMS), the last enzyme involved in the biosynthesis of sphingomyelin (SM), plays a critical role in the constitution of cell membrane and has impact on the expression of membrane proteins. SMS2, one of two SMS enzymes, is predominantly located in the plasma membrane, and is mainly expressed in the brain. Therefore, it is conceivable that SMS2 deficiency may have impact on expression of some membrane proteins, such as membrane-bound drug transporters.

ERM stable knockdown by siRNA reduced in vitro migration and invasion of human SGC-7901 cells.

Three closely related proteins, ezrin, radixin, and moesin (ERM), which primarily act as a linker between the plasma membrane and the cytoskeleton, are involved in many cellular functions, including regulation of actin cytoskeleton, control of cell shape, adhesion and motility, and modulation of signaling pathways. Although, ezrin is now recognized as a key component in tumor metastasis, the functional role of the radixin and moesin in tumor metastasis has not been established. In the present study, we chose highly metastatic human gastric carcinoma SGC-7901 cells, which express all of the ERM proteins as a model to examine the functional roles of these proteins in tumor metastasis.