OBJECTIVETo investigate the effects of autophagy activator (rapamycin, RAPA) and autophagy inhibitor (hydroxychloroquine, HCQ and 3-methyl adenine, 3-MA) on the proliferation, apoptosis and autophagy of multiple myeloma cell line of RPMI8226.

METHODSRPMI8226 cells were treated with autophagy regulating drugs of different concentrations. The proliferation and apoptosis of cells were determined by CCK-8 and flow cytometry, respectively. The expressions of apoptosis-related proteins BCL-2, caspase-3 and PARP protein were assessed by Western blot. Autophagy was detected by monodansylcadaverine staining. Autophagic protein (LC-3b) and apoptosis-related proteins (caspase-3, PARP and BCL-2) were analyzed by Western blot.

RESULTSRAPA and HCQ inhibited the proliferation of RPMI8226 in a concentration- and time-dependent manner, and increased the apoptosis. However, 3-MA did not show significantly inhibitory effect on the proliferation and apoptosis of RPMI8226. MDC staining showed that the more autophagic vacuoles could be detected in the higher concentration of RAPA, but the less autophagic vacuoles in the higher concentration of HCQ and 3-MA. Western blot showed that RAPA increased the expression of LC3-II/LC3-I, caspase-3 and PARP, but inhibited the expression of BCL-2. HCQ inhibited the expression of LC3-II/LC3-I and BCL-2, but increased the expression of caspase-3 and PARP. 3-MA inhibited the expression of LC3-II/LC3-I, but had no effect on the expression of caspase-3, PARP or BCL-2.

CONCLUSIONRapamycin can inhibit the proliferation, induce apoptosis and autophagy of RPMI 8226, the hydroxychloroquine can inhibit autophagy and proliferation of RPMI 8226, and induce apoptosis, the 3-MA can inhibit autophagy of RPMI 8226, but hardly has any effects on proliferation and apoptosis of RPMI 8226 cells.