Fig 4.

Mild heat shock-mediated HSP27 induction and concomitant sensitization of pancreatic cancer cell lines towards gemcitabine. (A) Immunoblotting displaying the expression levels of HSP27, HSP70 and HSP90 in the indicated established and short-term propagated primary pancreatic cancer cell lines upon heat shock at 41.8°C for 0, 15, 30, 60, 90, 120 or 150 min., respectively. ß-ACTIN served as loading control. (B and C) Proliferation assays comparing the sensitivity towards gemcitabine, with or without prior heat shock (HS) at 41.8°C for the indicated time-points of maximal HSP27 induction, including (B) or excluding (C) the detrimental effects of heat shock alone. Error bars represent SEM of at least three independent experiments. Asterisks mark statistical significance between two samples using the Student's t-test (*P < 0.05 **P < 0.01 ***P < 0.005).