Bombesin stimulates proliferation of human breast cancer cells in culture

Breast cancer cell-associated endopeptidase EC 24.11 modulates proliferative response to bombesin

“…GRP receptors have been described in breast cancer cell lines T47D and MDA-MB-436 (Giacchetti et al, 1990). Previously, we have shown that both BN and GRP stimulate proliferation of breast cancer cell lines when culture serum has been stripped of endogenous GRP-like peptides (Nelson et al, 1991); other workers have confirmed these findings (Yano et al, 1992).…”

“…This may be an explanation for the difference in BN dose required for mitogenesis in cell lines from these two cancer types. GRP/BN-stimulated colony formation is maximal at 50 nM in SCLC cells, but in the breast cancer cells significant stimulation is observed in the picomolar range in this laboratory (Carney et al, 1981;Nelson et al, 1991). However, this variation in mitogenicity may also be due to differing numbers of BN/GRP receptors on these cell lines.…”

“…Although only endothelin (which is not mitogenic) has been shown to be produced by the T47D cells (Schrey et al, 1992), the possibility of other as yet unidentified EC 3.4.24.11-labile growth factors being expressed by the T47D cells cannot be ruled out. Previous work in this laboratory found BN to be mitogenic for breast cancer cell lines in vitro, with 0.001-0.1 nM giving significant growth stimulation in the T47D cells (Nelson et al, 1991). The potentiation of BN-induced growth by phosphoramidon after 3 days is likely to be due to a prolonged half-life of the peptide in the medium.…”

“…After 24 h, the medium was removed and the treatments added in medium containing heat and dextran-coated charcoal-treated FCS (HT and DCC FCS) prepared as detailed previously (Nelson et al, 1987(Nelson et al, , 1991. Treatments were either control (medium only), 0.001-100 nM bombesin or 0.001-100 nM bombesin in the presence of phosphoramidon (0.1-100 ng ml -1 ).…”

Neuropeptide-Induced Androgen Independence in Prostate Cancer Cells: Roles of Nonreceptor Tyrosine Kinases Etk/Bmx, Src, and Focal Adhesion Kinase

“…Neuroendocrine cells are known to secrete neuropeptides, which are involved in diverse biological processes, including cellular proliferation, transformation, and invasion (74,94). These neuropeptides, exemplified by bombesin and NT, have been shown to be potent in vitro mitogens (73,74) and are implicated in a variety of human malignancies in the lung (31,36,89,90), breast (61,64), and prostate (16,44,51,56). For prostate cancers, it was shown that the receptors for bombesin/gastrin-releasing peptide (GRP) are present in all prostate cancer cell lines examined, including PC3, DU145, and LNCaP (9,13,55), and their expression levels are increased in more-advanced tumor specimens compared to less-advanced tumor specimens (55).…”