Sensitized cytotoxic effects of dexamethasone or radiation on multiple myeloma cells by chloroquine / 药学实践杂志

ABSTRACT

Objective To investigate the role and possible mechanism of combination use of chloroquine (CQ) with either dexamethasone (DEX) or radiation on multiple myeloma (MM) cell line U266 .Methods Cell viability of U266 treated with CQ alone ,or CQ combined with either DEX or radiation was measured by cell counting kit-8 (cck8) .CalcuSyn method was used to assess effect of drugs interaction .Cell viability and apoptosis of U266 pre-treated with CQ were also measured by cck8 and flow cytometry after radiation .Expression of B-cellymphoma-2 (Bcl-2) in U266 cells treated by CQ combined with DEX or radiation was determined by Western blot analysis .Results Either CQ or DEX displayed a dose dependent cell proliferation in-hibitory effect on U266 cells .Cytotoxic effect of DEX (125 μmol/L) on U266 cells was enhanced and expression of Bcl-2 pro-tein in U266 cells was decreased by combining with CQ (3 .9 μmol/L) .U266 cells were sensitized to radiation and cell death was induced by CQ (1 .0 μmol/L) .Conclusion CQ could sensitize cytotoxic effect of DEX or radiation on U 266 cells ,and the former was possibly related to down-regulation of Bcl-2 protein .