Showing papers by "Beppino C. Giovanella published in 1973"

Selective lethal effect of supranormal temperatures on mouse sarcoma cells.

Abstract: Summary The effects of supranormal temperatures upon normal (derived from normal, embryonal tissues) and neoplastic (derived from 3-methylcholanthrene-induced sarcomas) mesenchymal cells from C57BL/6 mice have been quantitatively studied in tissue culture. It has been found that exposure to a temperature of 42.5° for 2 hr or more has a selective lethal effect upon tumor cells (defined as cells capable of developing into a malignant tumor when injected into syngenic mice at doses of 1 × 10 6 cells or less in adults or 1 × 10 5 or less in newborns). No other biological characteristic studied (aneuploidy, length of time in culture, and rate of growth) could be correlated significantly with thermosensitivity. All the cultures of tumor-derived and tumor-producing cells exhibited the same high degree of thermosensitivity, i.e. , death of 95% of the cells after 2 hr exposure at 42.5°. All the cultured normal, nontumor-producing cells exhibited a lower degree of heat sensitivity, i.e. , death of 43% of the cells after 2 hr exposure to 42.5°. When a cell subline having a high tumor-producing ability was derived from a nontumor-producing line, it acquired a greater thermosensitivity, although its rate of growth was the same as that of the original line. These results indicate that the acquisition of biological malignant potential, both in vitro and in vivo , is accompanied by increased thermosensitivity in mouse mesenchymal cells.