[Effects of pre-heating on the sensitivity of K562 cell to tumor necrosis factor-alpha]

In order to study the effects of pre-heating on the sensitivity of cells to tumor necrosis factor-alpha (TNF-alpha), the K562 cells were pre-heated at 40 degrees C for different times to induce heat shock protein 70 (HSP70). To observe the effects of TNF-alpha concentration on the sensitivity of pre-heated cells, cells were pre-heated for 60 min and treated with TNF-alpha (50, 100, 200 and 400 U/ml) for 16 hours, and the cells vitalities were detected by MTT. In order to observe the effect of pre-heating time on the sensitivity of cells to TNF-alpha, the pre-heated cells were treated with 100 U/ml TNF-alpha for 24 hours. The levels of HSP70 were tested by reversed transcription-PCR(RT-PCR). The results showed that HSP70 could be induced by pre-heating, and reached its top level after 120 mins, and the sensitivity of non-heated cells to TNF-alpha was lower than that of pre-heated cells. To 100 U/ml TNF-alpha, the sensitivity was lowest after the cells were pre-heated for 120 min. The results suggested that pre-heated could induce the expression of HSP70 and inhibit the sensitivity of cell to TNF-alpha, the mechanism may be involved with the overexpression of HSP70.