Inhibition of growth of human malignant glioblastoma in nude mice by antagonists of bombesin/gastrin-releasing peptide.

Published

Journal Article

The effects of antagonists of bombesin/gastrin-releasing peptide (GRP) on the growth of human malignant glioblastoma cell line U-87MG xenografted into nude mice were evaluated. Nude mice bearing s.c. implanted U-87MG tumors were treated with bombesin/GRP antagonists RC-3095 and RC-3940-II. RC-3095 and RC-3940-II administered s.c. at a dose of 20 micrograms/day for 4 weeks decreased the volume of U-87MG xenografts by 60 and 74%, respectively, compared with controls. RT-PCR analysis showed that U-87MG xenografts expressed mRNA for bombesin receptor subtype (BRS)-1 (GRP receptor) and BRS-2 (neuromedin-B receptor), but the mRNA for GRP ligand was not detected in U-87MG cells suggesting that GRP may stimulate the growth of U-87MG glioblastomas by a paracrine mechanism. The levels of mRNA for c-fos oncogene were decreased by 30-40% in U-87MG tumors treated with RC-3095 or RC-3940-II. In U-373MG glioblastoma cells, which also express BRS-1, and U-87MG cells, cultured in vitro, GRP(14-27) induced the expression of c-fos mRNA, and some c-jun mRNA, in a time-dependent manner with the maximal effect occurring 2 h after the stimulation and a return to basal levels after 8 h. Antagonist RC-3940-II inhibited the stimulation of c-fos by GRP(14-27). Our results indicate that antagonists of bombesin/GRP inhibit the growth of U-87MG glioblastomas by a mechanism that may involve the downregulation of c-fos oncogene.

Full Text

Duke Authors

Cited Authors

  • Kiaris, H; Schally, AV; Sun, B; Armatis, P; Groot, K

Published Date

  • November 25, 1999

Published In

Volume / Issue

  • 18 / 50

Start / End Page

  • 7168 - 7173

PubMed ID

  • 10597318

Pubmed Central ID

  • 10597318

International Standard Serial Number (ISSN)

  • 0950-9232

Digital Object Identifier (DOI)

  • 10.1038/sj.onc.1203213

Language

  • eng

Conference Location

  • England