Abstract |
The regulatory peptide neurotensin NT has been proposed to exert an autocrine trophic effect on human colon cancers. In the present study, pro- neurotensin/ neuromedin N (proNT/NN) expression and processing were investigated in 13 human colon cancer cell lines using a combination of radioimmunoassay and HPLC techniques. All 13 cell lines displayed low to moderate levels of proNT/NN ranging from 10 to 250 fmol/mg protein. However, only 6 (HCT8, LoVo, HT29, C119A, LS174T, and coloDM320) processed the precursor. Three of the latter (HCT8, LS174T, and coloDM320) were analysed in detail with regard to proNT/NN processing pattern and were found to produce NT and large precursor fragments ending with the NT or NN sequence. They had no detectable level of NN. Such a processing pattern resembles that generated by the prohormone convertase PC5. Northern and Western blot analysis of prohormone convertase expression in the 3 cell lines revealed that they were devoid of PC1 and PC2, whereas they all expressed PC5. These data indicate that proNT/NN is a good marker of human colon cancer cell lines while NT is found in only about half of the cell lines. They also suggest that, in addition to NT, several proNT/NN-derived products, possibly generated by PC5, might exert an autocrine positive effect on human colon cancer growth.
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Authors | C Rovère, P Barbero, J J Maoret, M Laburthe, P Kitabgi |
Journal | Biochemical and biophysical research communications
(Biochem Biophys Res Commun)
Vol. 246
Issue 1
Pg. 155-9
(May 08 1998)
ISSN: 0006-291X [Print] United States |
PMID | 9600085
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Biomarkers, Tumor
- Peptide Fragments
- Protein Precursors
- RNA, Messenger
- RNA, Neoplasm
- neuromedin N
- Neurotensin
- Proprotein Convertase 5
- Proprotein Convertases
- Serine Endopeptidases
- Subtilisins
- Proprotein Convertase 2
- Aspartic Acid Endopeptidases
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Topics |
- Aspartic Acid Endopeptidases
(genetics, metabolism)
- Biomarkers, Tumor
(genetics, metabolism)
- Chromatography, High Pressure Liquid
- Colonic Neoplasms
(genetics, metabolism)
- Gene Expression
- Humans
- Neurotensin
(genetics, metabolism)
- Peptide Fragments
(genetics, metabolism)
- Proprotein Convertase 2
- Proprotein Convertase 5
- Proprotein Convertases
- Protein Precursors
(genetics, metabolism)
- Protein Processing, Post-Translational
- RNA, Messenger
(genetics, metabolism)
- RNA, Neoplasm
(genetics, metabolism)
- Radioimmunoassay
- Serine Endopeptidases
(genetics, metabolism)
- Subtilisins
(genetics, metabolism)
- Tumor Cells, Cultured
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