TY - JOUR
T1 - Gastrin 1-6 promotes growth of colon cancer cells through non-CCK receptors
AU - Copps, Jeffrey
AU - Ahmed, Shawn
AU - Murphy, Richard F.
AU - Lovas, Sándor
N1 - Funding Information:
This work was supported by the NIH-INBRE grant 1 P20 RR16469 and the Carpenter Endowed Chair in Biochemistry, Creighton University.
PY - 2007/3
Y1 - 2007/3
N2 - Our previous studies have shown that stimulation of proliferation of DLD-1 and HT29 human colonic cancer cells by nanomolar gastrin (G17) and carboxymethyl gastrin (G17Gly) and reversal of growth by micromolar G17 and G17Gly involves binding sites which can neither be CCK1 nor CCK2 receptors; the N terminal fragment, G17(1-12), is sufficient to increase the number of HT-29 cells by binding the higher affinity binding site but is without a suppressing effect through the lower affinity site. In this study with DLD-1 cells, competitive binding using 125I-G17(1-12) showed that G17(1-12) binds both high and low affinity sites, as do G17 and G17Gly. G17(1-6)-NH2, even without the central-to-C-terminal portion of G17, was still able to bind a single site and to promote a dose-dependent increase in cell number at nanomolar concentrations. The results indicate the presence of a non-CCK receptor on human colonic cancer cells which could mediate the tumor-promoting activity of the N-terminal-to-central portion of G17Gly which, unlike G17, is produced by such cells.
AB - Our previous studies have shown that stimulation of proliferation of DLD-1 and HT29 human colonic cancer cells by nanomolar gastrin (G17) and carboxymethyl gastrin (G17Gly) and reversal of growth by micromolar G17 and G17Gly involves binding sites which can neither be CCK1 nor CCK2 receptors; the N terminal fragment, G17(1-12), is sufficient to increase the number of HT-29 cells by binding the higher affinity binding site but is without a suppressing effect through the lower affinity site. In this study with DLD-1 cells, competitive binding using 125I-G17(1-12) showed that G17(1-12) binds both high and low affinity sites, as do G17 and G17Gly. G17(1-6)-NH2, even without the central-to-C-terminal portion of G17, was still able to bind a single site and to promote a dose-dependent increase in cell number at nanomolar concentrations. The results indicate the presence of a non-CCK receptor on human colonic cancer cells which could mediate the tumor-promoting activity of the N-terminal-to-central portion of G17Gly which, unlike G17, is produced by such cells.
UR - http://www.scopus.com/inward/record.url?scp=33846794616&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33846794616&partnerID=8YFLogxK
U2 - 10.1016/j.peptides.2006.10.008
DO - 10.1016/j.peptides.2006.10.008
M3 - Article
C2 - 17126952
AN - SCOPUS:33846794616
VL - 28
SP - 632
EP - 635
JO - Peptides
JF - Peptides
SN - 0196-9781
IS - 3
ER -