[Expressions of JWA protein and heat stress protein 70 induced by cell differentiation inducers combined with heat stress in K562 cells].
OBJECTIVE
To study how the combined effects of various differentiation inducers and heat stress on the expression of JWA protein in K562 cell, the relationship between JWA and Hsp70 expression, and the signal regulation mechanism possibly involved.


METHODS
The experimental model was established in K562 cells. Various directional differentiation inducers (TPA, Ara-C, hemin, adriamycin, ATRA and As(2)O(3)) were used alone or combined with heat shock treatment (42 degrees C, 2 h). Western blot was used for detecting expressions of JWA, Hsp70, heat stress factor 1 (HSF1) and HSF2.


RESULTS
(1) The expressions of both JWA protein and Hsp70 were significantly up-regulated after K562 cells treated by TPA (100, 200 ng/ml) or adriamycin (4 x 10(-8) mol/L) 48 h, and followed by heat shock (42 degrees C, 2 h). However, the opposite effects were observed when the cells treated by hemin (3 x 10(-5) mol/L, 48 h), Ara-C (80 ng/ml, 48 h) and As(2)O(3) (1 x 10(-6) mol/L, 48 h) followed by 2 h heat shock. No obvious changes were found when the cells treated by ATRA (1 x 10(-6) mol/L, 48 h) alone or followed by heat shock. (2) Both the heat shock transcriptional factors HSF1 and HSF2 did not show any significant changes when K562 cells were treated with various differentiation inducers and followed by heat stress.


CONCLUSIONS
JWA not only takes part in the regulation of K562 cellular differentiation, but also of heat stress, it might be the co-target gene of several differentiation inducers and heat stress. The expression of Hsp70 seems not mediated by both HSF1 and HSF2 in K562 cells undergoing directional differentiation or heat stress treatment. JWA is likely to be a new signal molecule similar to Hsp70 signal pathways. The results show that JWA takes part in the mechanism of K562 cell response to heat stress.
Mao
Wen-ge
WG
Department of Molecular Toxicology, the Jiangsu Key Laboratories of Human Functional Genomics and Applied Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, China.
Li
Ai-ping
AP
Ye
Jian
J
Huang
Shu
S
Li
Ai-qun
AQ
Zhou
Jian-wei
JW
D015153:Blotting, Western; D004268:DNA-Binding Proteins / Q000032:analysis; D005434:Flow Cytometry; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000032:analysis*; D006358:Hot Temperature; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D020014:K562 Cells; D026901:Membrane Transport Proteins; D014157:Transcription Factors / Q000032:analysis
C484566:ARL6IP5 protein, human; D004268:DNA-Binding Proteins; C000619706:HSF1 protein, human; D018840:HSP70 Heat-Shock Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D047908:Intracellular Signaling Peptides and Proteins; D026901:Membrane Transport Proteins; D014157:Transcription Factors; C070389:HSF2 protein, human