Mammalian cells adapted to growth at pH 6.7 have elevated HSP27 levels and are resistant to cisplatin.

HSP27 levels are elevated in two Chinese hamster cell lines and in a human melanoma cell line adapted to growth at pH 6.7. The level of HSP72 is elevated in the melanoma cell line but not in the hamster cell lines adapted to growth at pH 6.7. HSC73 levels are not elevated in any of the adapted cell lines. Low pH adapted cells from all cell lines are resistant to cisplatin. It is proposed that elevated HSP27 levels in low pH-adapted cells may play a role in resistance to hyperthermia and resistance to cisplatin.