engleski

Effects of inducible Hsp70 on staurosporine induced apoptosis

Apoptosis, the process of programmed cell death, is characterized by a sequence of precisely regulated events that culminate in the self destruction of a cell. Expression of heat shock proteins (Hsp) is known to correlate with increased resistance to apoptosis induced by a range of diverse cytotoxic agents and has been implicated in chemotherapeutic resistance of tumors and carcinogenesis. Staurosporine, often used for apoptosis induction, is an alkaloid with ability to inhibit protein kinases through the prevention of ATP binding. Hsp70 is one of the major heat shock inducible proteins of the Hsp family. Jurkat cells (acute T cell leukemia), if exposed to heat stress (30 minutes, 44°C), express higher concentration of inducible Hsp70 (9-12.5 times elevation compared to the control cells), depending on the time left for the recovery in custom cell culture conditions. Induction of apoptosis with staurosporine was assessed at morphological level, by Flow Cytometry analysis, and at the level of terminal event of cell death, DNA fragmentation, by immune detection of single- and double-stranded DNA breaks. It is shown that increased concentration of inducible Hsp70 shifts the percentage of live cells from 37% to 55% (1, 5x), predicting the role of inducible Hsp70 in protection against staurosporine induced apoptosis with involvement of 36%.

apoptosis; staurosporine; heat shock; Hsp70

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