A bombesin receptor subtype-3 peptide increases nuclear oncogene expression in a MEK-1 dependent manner in human lung cancer cells

Eur J Pharmacol. 2001 Jan 19;412(1):13-20. doi: 10.1016/s0014-2999(00)00941-9.

Abstract

A synthetic peptide, (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) was used to investigate the signal transduction mechanisms of bombesin receptor subtype-3. Using NCI-1299#5 human lung cancer cells stably transfected with bombesin receptor subtype-3, 100 nM (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) elevated the cytosolic Ca2+ from 150 to 250 nM within 10 s. Addition of (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) caused phosphorylation of mitogen activated protein kinase in a time- and concentration-dependent manner. The mitogen activated protein kinase phosphorylation caused by (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) was inhibited by 2'-amino-3'-methyoxyflavone (PD98059), a mitogen activated protein kinase kinase (MEK-1) inhibitor. Using a luciferase reporter gene construct, (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) caused Elk-1 activation after 10 min and the increase in Elk-1 activation caused by (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) was inhibited by PD98059 as well as a dominant-negative MEK-1. (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) caused increased c-fos as well as c-jun mRNAs 1 h after addition to NCI-H1299#5 cells. The 47-fold increase in c-fos mRNA caused by 100 nM (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) was inhibited by PD98059, a dominant-negative MEK-1 and a substance P antagonist but not (3-phenylpropanoyl-D-Ala(24), Pro(26), Psi(26,27), Phe(27))GRP-(20-27) (BW2258U89), a GRP receptor antagonist. These results indicate that (D-Phe(6), beta-Ala(11), Phe(13), Nle(14))bombesin-(6-14) caused increased nuclear oncogene expression and upstream events include mitogen activated protein kinase phosphorylation and Elk-1 activation.

MeSH terms

  • Bombesin / analogs & derivatives*
  • Bombesin / pharmacology
  • Calcium / metabolism
  • DNA-Binding Proteins*
  • Enzyme Inhibitors / pharmacology*
  • Flavonoids / pharmacology*
  • Genes, fos / drug effects*
  • Genes, fos / physiology
  • Humans
  • Lung Neoplasms / metabolism*
  • Mitogen-Activated Protein Kinase Kinases / antagonists & inhibitors*
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Oncogenes / drug effects
  • Oncogenes / physiology
  • Peptide Fragments / pharmacology
  • Proto-Oncogene Proteins / drug effects*
  • Proto-Oncogene Proteins / metabolism
  • RNA, Messenger / drug effects*
  • RNA, Messenger / metabolism
  • Receptors, Bombesin / drug effects*
  • Receptors, Bombesin / metabolism
  • Transcription Factors*
  • Tumor Cells, Cultured
  • ets-Domain Protein Elk-1

Substances

  • DNA-Binding Proteins
  • ELK1 protein, human
  • Enzyme Inhibitors
  • Flavonoids
  • Peptide Fragments
  • Proto-Oncogene Proteins
  • RNA, Messenger
  • Receptors, Bombesin
  • Transcription Factors
  • bombesin receptor subtype 3
  • ets-Domain Protein Elk-1
  • bombesin (6-14), D-Phe(6)-Leu(13)-psi(CH2NH)-Phe(14)-
  • Mitogen-Activated Protein Kinase Kinases
  • Bombesin
  • 2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one
  • Calcium