HGH protects human lymphocates from irradiation-induced cell death

Lempereur L, Brambilla D, Scoto GM, D'Alcamo M, Goffin V, Crosta L, Palmucci T, Rampello L, Bernardini R, Cantarella G.

Department of Experimental and Clinical Pharmacology, University of Catania, Italy. Department of Pharmaceutical Sciences, University of Catania, Italy. INSERM Unite 344-Endocrinologie Moleculaire, Faculte de Medicine Necker, Paris, France. Department of Oncology, University of Palermo, Italy. Department of Radiology, University of Catania, Italy. Department of Neurology, University of Catania, Italy.

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. British Journal of Pharmacology (2003) 138, 1411-1416. doi:10.1038/sj.bjp.0705173