ABSTRACT
Objective To investigate the role of the p38 MAPK pathway in the formation of cytoplasmic vacuoles .Methods Af-ter treated with Anisomycin ,SB203580 or SP600125 ,images of HepG2 ,LM3 ,QBC939 ,Hela and A549 cells were recorded by light microscopy and taken at a magnification of 400 × .The effects of anisomycin ,SB203580 and SP600125 on the activity of p38 and JNK were measured by Western blot .LM3 and A549 cells were stained with the ER-tracker red and the lyso-tracker red and subjec-ted to confocal microscopy analysis .Results (1)Anisomycin could abolish cytoplasmic vacuolization of HepG2 cells .(2)p38 MAPK activation was responsible for anisomycin-induced cytoplasmic vacuolization abolishment .(3)p38 MAPK blocking initiated cytoplas-mic vacuoles formation in various cancer cell lines .(4)p38 MAPK blocking-induced cytoplasmic vacuoles disrupted the integrity of endoplasmic reticulum .(5)p38 MAPK blocking reversibly induced cytoplasmic vacuoles formation .Conclusion These observations provide direct evidence for a role of p38 MAPK signaling in regulating the formation of cytoplasmic vacuoles .