RESPONSE OF THE MICROTUBULAR CYTOSKELETON FOLLOWING HYPERTHERMIA AS APROGNOSTIC INDICATOR OF SURVIVAL OF CHINESE-HAMSTER OVARY CELLS

Purpose: The response of the microtubular (MT) cytoskeleton to hyperth ermia was assessed as prognostic indicator of cytotoxicity. Methods an d Materials: Heat-induced collapse and subsequent recovery of the MT s ystem were compared with survival for both nonthermotolerant (NT) and thermotolerant (TT) G1 populations of Chinese hamster ovary (CHO) cell s, The response of the MT system was monitored using immunofluorescenc e staining. The G1 populations of NT and TT cells were heated by subme rsion in 45.0 and 43.0 degrees C waterbaths. Results: Heat-induced per inuclear collapse of the MT system did not correlate with survival for the NT and TT populations. However, recovery of the organization of t he MT cytoskeleton was correlatable with survival. The regression line of survival plotted as a function of MT recovery is fit by: y = -0.43 + 1.03x, r(2) = 0.95 (p < 0.0005). Conclusion: Restoration of the org anization of the MT cytoskeleton following hyperthermia may be used as a prognostic indicator of survival of CHO cells heated in G1.