[Mechanism of apoptosis induced by trichostatin A in leukemia Molt-4 cells analyzed by microarray].
OBJECTIVE
Histone deacetylase is overexpressed in a variety of cancers and is closely correlated with oncogenic factors. A histone-deacetylase inhibitor, trichostatin A (TSA), has been shown to induce apoptosis in many cancer cells at submicromolar concentrations. However, the mechanism remains unknown. This study was to investigate the underlying mechanism of trichostatin A on apoptosis of Molt-4 cells by characterizing the global gene expression profiles before and after TSA treatment.


METHODS
PI single-labeled flow cytometry, MTT and DNA ladder were used to observe the effect of TSA on apoptosis of MOLT-4 cells and normal human peripheral blood mononuclear cells (PBMC). Microarray and reverse transcription-polymerase chain reaction (RT-PCR) and Western blot were used to detect the differentially expressed genes of Molt-4 cells after incubation with TSA.


RESULTS
TSA could induce apoptosis in Molt-4 cells in a dose and time-dependent manner. Besides, the dose of TSA within the time duration which could induce significant apoptosis in Molt-4 cells did not demonstrate apparent cytotoxicity to PBMCs. After incubation with TSA for 9 hours, 313 genes were detected down-regulated by microarray. Proteins encoded by these genes included signal transduction molecules, transcription factors, enzymes etc., which were involved in the regulation of cell growth, differentiation and survival. STAT5A, MYC and ikaros were down-regulated by 80.4%, 77.3% and 83.1%, respectively. The changes of the three genes were confirmed by RT-PCR and the changes of STAT5A and MYC were further confirmed by Western blot.


CONCLUSIONS
The inhibition of cell growth and induction of apoptosis by TSA in Molt-4 cells may be due to the changes of pro-proliferation genes and anti-apoptosis genes.
Hong
Zhen-Ya
ZY
Department of Hematology, Tongji Hospital, Tongji Medical College, Huazhong University of Science &Technology, Wuhan, Hubei, 430030, P. R. China.
Yi
Li-Sha
LS
Miao
Xin-Yu
XY
Lu
Yun-Ping
YP
Zhou
Jian-Feng
JF
Liu
Wen-Li
WL
D017209:Apoptosis / Q000187:drug effects*; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D056572:Histone Deacetylase Inhibitors; D006655:Histone Deacetylases / Q000494:pharmacology; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D051740:Ikaros Transcription Factor / Q000096:biosynthesis / Q000235:genetics; D015458:Leukemia, T-Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D007963:Leukocytes, Mononuclear / Q000187:drug effects; D040081:Protein Array Analysis; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D050799:STAT5 Transcription Factor / Q000096:biosynthesis / Q000235:genetics; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000235:genetics
D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; C497239:IKZF1 protein, human; C489427:MYC protein, human; D016271:Proto-Oncogene Proteins c-myc; D012333:RNA, Messenger; D050799:STAT5 Transcription Factor; C494092:STAT5A protein, human; D025521:Tumor Suppressor Proteins; D051740:Ikaros Transcription Factor; C012589:trichostatin A; D006655:Histone Deacetylases