Effect of insulin-like growth factor-I gene therapy on the somatotropic axis in experimental prolactinomas

CONSOLE G.M.; HEREÑÚ CB; CAMIHORT GA; LUNA GC,; FERESE C; GOYA RG

CELLS TISSUES ORGANS

Karger AG,

Lugar: Basel; Año: 2009 vol. 190 p. 20 - 26

1422-6405

Insulin-like growth factor-I (IGF-I) provides a physiologic feedback effect within the somatotropic axis. Gene therapy was implemented in young female Sprague-Dawley rats which received 2 pituitary stereotaxic injections of a control recombinant adenoviral vector expressing green fluorescent protein (RAd-GFP) or IGF-I (RAd-IGF-I). The animals were sacrificed 7 days after injection. Previously, on day -23, the experimental groups received subcutaneous implants of 17-beta estradiol. Morphometric analysis revealed that the somatotrope cells in estrogen-treated rats without stereotaxic injections showed a significant (p < 0.01) increase in the cell size compared with intact controls (59.9 +/- 1.1 vs. 42.9 +/- 1.2 mum(2)) and had a significant (p < 0.05) decrease in cell density with respect to intact animals (10.5 +/- 0.1 vs. 19.7 +/- 1.7). The treatment of pituitary adenomas with RAd-IGF-I induced a significant (p < 0.05) decrease in cell size with respect to E(2) + RAd-GFP (51.3 +/- 0.3 vs. 58.9 +/- 0.3 mum(2)) and no changes in cell density compared with RAd-GFP-injected animals (12.8 +/- 1.7 vs. 10.5 +/- 0.1). Serum growth hormone was higher (p < 0.01) in estrogen-treated animals versus controls (146.7 +/- 6 vs. 73.9 +/- 9 ng/ml). In rats carrying estrogen-induced adenomas, RAd-IGF-I injection induced a significant (p < 0.05) decrease in serum growth hormone compared to RAd-GFP-injected animals (107.5 +/- 7 vs. 142.4 +/- 9 ng/ml). IGF-I gene therapy appears to be an effective approach for the treatment of experimental somatomammotropic pituitary tumors and could be potentially useful as an adjuvant of conventional therapies. Copyright © 2008 S. Karger AG, Basel.