Gastrin-releasing peptide (GRP), a member of the bombesin family of peptides, has been shown to have mitogenic activity in small cell lung carcinoma (SCLC), and to be produced by SCLC in an autocrine fashion.
Gastrin-releasing peptide (Pro-GRP), a member of the bombesin family of peptides, has been shown to have mitogenic activity in small cell lung carcinoma (SCLC), and to be produced by SCLC in an autocrine fashion.
Bombesin (BB)-like peptides synthesized by neuroendocrine tumor small cell lung cancer (SCLC) bind to BB receptors (BBRs), causing phosphatidylinositol turnover and phosphorylation of extracellular signal-regulated kinase (ERK).
A hallmark of small cell lung carcinoma (SCLC) is the expression of autocrine growth factors such as neurotensin and gastrin-releasing peptide, which bind to cellular receptors and stimulate cell division.
Additionally in stage III and IV, the concordance rates of ProGRP ≥71 ng/L and ProGRP ≥99 ng/L were also higher than ProGRP ≥300 ng/L (both P<0.001), which was conventionally indicated for SCLC.
After multiple passages, UMC-SCLC-1 gradually changed its culture characteristics to a cell line, UMC-SCLC-1A, with morphological features of large cell anaplastic carcinoma, an altered growth pattern, decrease in calcitonin, and increase in radioresistance but retained the other biochemical markers of classic SCLC (bombesin and dopa decarboxylase production).
Amplification of the preproGRP message was detected in SCLC cell lines (LU165, SBC1, SBC2, and SBC3) but not in other NSCLC cell lines (A549, ABC1, EBC1, and Oka-1).
Examination of the structure of prepro-GRP transcripts found in SCLC reveals three types of prepro-GRP mRNA which differ in the structure of a putative GRP-associated peptide in the pro-GRP precursor.
In a number of tumors, such as small cell lung cancer (SCLC), bombesin (BB) like peptides and neurotensin (NTS) function as autocrine growth factors whereby they are secreted from tumor cells, bind to cell surface receptors and stimulate growth.
In addition, the effect of BBI on the growth factor processing of proGRP by SCLC cells and on mRNA levels for prohormone convertase 1 and 2 (PC1 and PC2) in SCLC cells was examined.
In nude mice, a subcutaneously-inoculated tumor of SBC5 cells infected with AdGRP-TK in advance regressed completely after intraperitoneal administration of GCV.
In the two SCLC cell lines expressing GRP we find a single transcription start site for GRP mRNA, and near this site we find four DNase I hypersensitive sites.
In this study, we determined whether mRNA of bombesin receptors is detectable in PB or peripheral blood progenitor cell (PBPC) samples from patients with small cell lung cancer.
Our results provide evidence for the expression of the bombesin gene in small cell carcinoma of the lung at a cellular level and show that probombesin mRNA is highly expressed in these tumors.
Pro-gastrin-releasing peptide (ProGRP), neuron specific enolase (NSE), carcinoembryonic antigen (CEA) and cytokeratin 19-fragments (CYFRA 21-1) in patients with lung cancer in comparison to other lung diseases.