Insulin Effects on Survival of Human Multiple Myeloma Cells.

Insulin effects of human multiple myeloma cell survival were studied on RPMI1640, RPMI8226, and IM9 lines differing by differentiation degree. The effects of exogenous insulin on tumor cell growth and survival varied. Insulin alone did not improve the viability of myeloma cells, while in combination with serum growth factors increased it. The IM9 cells with immunophenotype (CD(138+), CD(38-), CD(45+), CD(56-), CD(19+)) exhibited the highest sensitivity to serum growth factors, while RPMI1640 and RPMI8226 cells with (CD(138+), CD(38+), CD(45-), CD(56±), CD(19-)) immunophenotype were less sensitive. Studies of gene expression showed a significantly lower level of IRA mRNA expression in IM9 vs. RPMI1640 and RPMI8226 cells.