OBJECTIVETo investigate the expression of JWA after hemin and (or) thermal stress exposure.

METHODSThe expression of JWA was determined by Western blot. RT-PCR was carried out for evaluation of the expression of JWA mRNA. The JWA promoter transcription activity analysis was performed by CAT-ELISA.

RESULTSThe expression of JWA protein was significantly increased by 3.23 +/- 0.57 times of control in K562 cells after treated by hemin (50 micromol/L) for 1 week, and the similar pattern was observed in the cells after treatment with thermal stress (42 degrees C) for 2 hours (increased by 8.00 +/- 1.73 times). The expression of JWA mRNA was also significantly elevated by 1.37 +/- 0.06 times in K562 cells treated by hemin (30 micromol/L) for 48 hours, and with a similar regulation pattern (increased by 1.87 +/- 0.13 times) by treatment with thermal stress (42 degrees C) for 30 minutes. However, an antagonistic effect was observed by treatment of K562 cells with hemin (30 micromol/L, 48 hours) followed by thermal stress (42 degrees C, 30 minutes). The CAT-ELISA further confirmed that hemin or thermal stress treatment alone up-regulated JWA transcription activity while the effects could be counteracted partly by the combined treatment of the both.

CONCLUSIONThe hemin and thermal stress may regulate JWA expression via distinct intracellular signal transduction pathways.