engleski

Heat shock protein 70 in drug-resistant cells: induction by hyperthermia and anticancer drugs.

Heat shock proteins (Hsp) are a family of proteins whose synthesis is induced by heat shock and a wide variety of other stresses (e. g. anoxia, heavy metal ions, amino acid analogs). This induction represents a rapid and highly conserved response to proteotoxic insult. Due to development of drug-resistance, the population of drug-resistant cells could be selected, that would have increased basal level of Hsp70. The altered constitutive and inducible levels of Hsp70 in drug resistant cells may influence their response to combined hyperthermia and anticancer drug treatment. In the present study, the constitutive levels of Hsp70 and induction of these proteins by hyperthermia and two anticancer drugs (used for resistance development) were determined in cervical and laryngeal carcinoma cells. The levels of Hsp70 were quantified by Western blot. Constitutive levels of Hsp70 were similar in parental and drug-resistant cells suggesting that Hsp70 is not involved in drug-resistance. Hyperthermic treatment induced Hsp70 in all examined cell lines but with different kinetics between drug-resistant and parental cells. Following the treatment with anticancer drugs, Hsp70 was induced only in cisplatin-resistant laryngeal cells. In conclusion, kinetics of Hsp70 induction (stress-type and cell-type specific), may be different in drug-resistant cells as compared to parental cells. The observed alterations in Hsp70 induction in drug resistant and parental cells should be taken into account when combined treatments (i. e. hyperthermia and anticancer drugs) are planned

heat shock protein; drug-resistance; tumor cells; hyperthermia; anticancer drug

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