In vitro sensitivity of human hematopoietic progenitor cells to hyperthermia: critical temperature for cells to survive and its application to in vitro purging.
Normal tissue toxicity is a major concern in cancer therapy. Since the hyperthermic killing of normal human hematopoietic progenitor cells including multilineage progenitor cells (CFU-mix) other than committed granulocyte-macrophage progenitor cells (CFU-GM) is not known, we have studied the thermal sensitivity of various types of human hematopoietic progenitor cells: early and late erythroid progenitors (CFU-E and BFU-E), CFU-GM and CFU-mix using semisolid clonogenic assays. When these progenitor cells were exposed at 42-44 degrees C for 2 h, their thermal sensitivity always appeared to be in the order of CFU-E greater than BFU-E greater than CFU-GM greater than CFU-mix; the CFU-mix was the most tolerant to heat damage. In addition, the survival of human hematopoietic progenitor cells decreased exponentially in exposure time- and temperature-dependent manner. At 44 degrees C human hematopoietic progenitor cells including CFU-mix dropped dramatically in number and therefore were unable to form colonies in vitro after exposure for 2 h. This suggests that 44 degrees C may be the critical temperature for the CFU-mix to survive in vitro. Thus temperatures selected for hyperthermia used to purge residual leukemic cells in remission marrow grafts should be 43 degrees C or lower.
Moriyama
Y
Y
1st Department of Internal Medicine, Niigata University School of Medicine, Japan.
Nikkuni
K
K
Saito
H
H
Aoki
A
A
Furukawa
T
T
Imanari
A
A
Narita
M
M
Kishi
K
K
Takahashi
M
M
Shibata
A
A
D002470:Cell Survival / Q000502:physiology; D003602:Cytotoxicity, Immunologic; D015672:Erythroid Precursor Cells / Q000502:physiology; D005334:Fever / Q000150:complications / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000502:physiology*; D006801:Humans; D013696:Temperature