Heat-induced accumulation of p53 and hsp72 is suppressed in lung fibroblasts from the SCID mouse

Purpose : To investigate how DNA-dependent protein kinase (DNA-PK) contributes to p53-dependent signal transduction after heat shock, thermosensitivity and accumulation of p53 and hsp72 after heat shock in lung fibroblasts derived from the SCID mouse were analysed. Materials and methods : Thermosensitivity at 44°C in colony-forming units and Western blot analysis of p53 and hsp72 were analysed. Results : The results indicated that (1) the thermosensitivity at 44°C of SCID cells was higher than that of parental cells and (2) heat-induced accumulation of p53 and hsp72 was abolished and suppressed in SCID cells as compared with that in parental cells respectively. Conclusions : The findings suggest that the catalytic subunit of DNA-PK may play an important role upstream of p53 and hsp72, which are possible determinants of cellular thermosensitivity.