Neuromedin B and its receptor are mitogens in both normal and malignant epithelial cells lining the colon
| Autor: | Damien Matusiak, Jianxin Yang, Richard V. Benya, Kristina A. Matkowskyj, Rajkumar Nathaniel, Sarah C. Glover |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
medicine.medical_specialty
Colon Neurokinin B Physiology Neuropeptide Biology chemistry.chemical_compound Cell Line Tumor Physiology (medical) Gastrin-releasing peptide Internal medicine medicine Gastrin-releasing peptide receptor Humans RNA Messenger Intestinal Mucosa Receptor Cells Cultured Hepatology Gastroenterology Bombesin Epithelial Cells Neuromedin B Immunohistochemistry Epithelium Receptors Bombesin medicine.anatomical_structure Endocrinology chemistry Cell culture Colonic Neoplasms Cancer research Mitogens Cell Division |
| Zdroj: | American Journal of Physiology-Gastrointestinal and Liver Physiology. 288:G718-G728 |
| ISSN: | 1522-1547 0193-1857 |
| Popis: | Bombesin-like peptides are uniformly thought to act as mitogens in cancer. Yet by studying human tissues, we have recently shown that bombesin and its mammalian homologue gastrin-releasing peptide act as morphogens, promoting tumor differentiation when aberrantly upregulated in colon cancer. In contrast, little is known about the bombesin-like peptide neuromedin B (NMB) and its receptor (NMB-R) in the human gastrointestinal tract. We therefore studied their presence and function in normal and malignant human colonic epithelia. Anti-NMB monoclonal antibodies were made against keyhole limpet hemocyanin (KLH)-conjugated human NMB, whereas anti-NMB-R antibodies were raised in rabbits against KLH-conjugated peptides corresponding to the third intracellular loop and COOH-terminal tail of the receptor protein. NMB antibody recognized two bands at approximately 1.2 kDa and approximately 1.5 kDa. NMB-R antibodies recognized a band at 80 kDa (predicted 43 kDa); whereas treatment with the deglycosylating agent peptide-N-glycosidase generated bands at 65, 47, and 43 kDa. By immunohistochemistry, both NMB and NMB-R were expressed in normal and cancerous colonic epithelial tissues. In cancer, the amount of NMB was similar to that expressed by proliferating epithelial cells located within the crypt. In contrast, NMB-R expression was increased in cancer, with higher levels detected in better differentiated tumor cells. To assess NMB function, proliferation was determined in the nonmalignant human colonic epithelial cell line NCM-460 and in the colon cancer cell lines Caco-2 and HT-29. Exogenously added NMB was 50-100% more efficacious than gastrin-releasing peptide in causing tumor cell proliferation, whereas only NMB increased NCM-460 cell proliferation. These findings indicate that NMB and its receptor are coexpressed by proliferating cells in which they act in an autocrine fashion with similar and modest potency in both normal and malignant colonic epithelial cells. |
| Databáze: | OpenAIRE |
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