Growth hormone protects human lymphocytes from irradiation-induced cell death.
1. Undesired effects of cancer radiotherapy mainly affect the hematopoietic system. Growth hormone (GH) participates in both hematopoiesis and modulation of the immune response. We report both r-hGH cell death prevention and restoration of secretory capacities of irradiated human peripheral blood lymphocytes (PBL) in vitro. 2. r-hGH induced cell survival and increased proliferation of irradiated cells. Western blot analysis indicated that these effects of GH were paralleled by increased expression of the antiapoptotic protein Bcl-2. 3. r-hGH restored mitogen-stimulated release of IL-2 by PBL. Preincubation of irradiated lymphocytes with the growth hormone receptor (GHR) antagonists B2036 and G120 K abrogated r-hGH-dependent IL-2 release. 4. These results demonstrate that r-hGH protects irradiated PBL from death in a specific, receptor-mediated manner. Such effect of r-hGH on PBL involves activation of the antiapoptotic gene bcl-2 and prevention of cell death, associated with preserved functional cell capacity. Finally, potential use of GH as an immunopotentiating agent could be envisioned during radiation therapy of cancer.
Lempereur
Laurence
L
Department of Experimental and Clinical Pharmacology, University of Catania, Italy.
Brambilla
Daria
D
Scoto
Giovanna Maria
GM
D'Alcamo
Maria
M
Goffin
Vincent
V
Crosta
Lucia
L
Palmucci
Tullio
T
Rampello
Liborio
L
Bernardini
Renato
R
Cantarella
Giuseppina
G
D016923:Cell Death / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D002478:Cells, Cultured; D019382:Human Growth Hormone / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects*; D011994:Recombinant Proteins / Q000494:pharmacology
D011994:Recombinant Proteins; D019382:Human Growth Hormone