Effects of gastrin 17 on beta-catenin/Tcf-4 pathway in Colo320WT colon cancer cells.

Abstract

AIM:

To explore the effect of gastrin 17 (G17) on beta-catenin/T cell factor-4 (Tcf-4) signaling in colonic cancer cell line Colo320WT.

METHODS:

The pCR3.1/GR plasmid, which expresses gastrin receptor, cholecystokinin-2 receptor (CCK-2R), was transfected into a colonic cancer cell line Colo320 by Lipofectamine (TM)2000 and the stably expressing CCK-2R clones were screened by G418. The expression levels of gastrin receptor in the Colo320 and the transfected Colo320WT cell line were assayed by RT-PCR. Colo320WT cells were treated with G17 in a time-dependent manner (0, 1, 6, 12, 24 and 48 h), then with L365,260 (Gastrin(17) receptor blocker) for 30 min, and with G17 again for 12 h or L365,260 for 12 h. Expression levels of beta-catenin in a TX-100 soluble fraction and TX-100 insoluble fraction of Colo320WT cells treated with G17 were detected by co-immuniprecipation and Western blot. Immunocytochemistry was used to examine the distribution of beta-catenin in CoLoWT320 cells. Expression levels of c-myc and cyclin D1 in Colo320WT cells treated with G17 were assayed by Western blot.

RESULTS:

Expression levels of beta-catenin in the TX-100 solution fraction decreased apparently in a time-dependent fashion and reached the highest level after G17 treatment for 12 h, while expression levels of beta-catenin in the TX-100 insoluble fraction were just on the contrary. Immunocytochemistry showed that beta-catenin was translocated from the cell membranes into the cytoplasm and nucleus under G17 treatment. Expression levels of c-myc and cyclin D1 in the G17-treated Colo320WT cells were markedly higher compared to the untreated Colo320WT cells. In addition, the aforementioned G17-stimulated responses were blocked by L365,260.

CONCLUSION:

Gastrin17 activates beta-catenin/Tcf-4 signaling in Colo320WT cells, thereby leading to over-expression of c-myc and cyclin D1.

• Authors: Jun Cao, Jie-Ping Yu, Chao-Hong Liu, Lan Zhou, Hong-Gang Yu
• Journal: World journal of gastroenterology (World J Gastroenterol) Vol. 12 Issue 46 Pg. 7482-7 (Dec 14 2006) ISSN: 1007-9327 [Print] United States
• PMID: 17167838 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• CTNNB1 protein, human
• Cyclin D
• Cyclins
• DNA, Complementary
• Gastrins
• MYC protein, human
• Proto-Oncogene Proteins c-myc
• Receptor, Cholecystokinin B
• Recombinant Proteins
• TCF Transcription Factors
• TCF7L2 protein, human
• Transcription Factor 7-Like 2 Protein
• beta Catenin
• gastrin 17

Topics

• Base Sequence
• Cell Line, Tumor
• Colonic Neoplasms (drug therapy, genetics, metabolism)
• Cyclin D
• Cyclins (metabolism)
• DNA, Complementary (genetics)
• Gastrins (pharmacology)
• Humans
• Proto-Oncogene Proteins c-myc (metabolism)
• Receptor, Cholecystokinin B (genetics, metabolism)
• Recombinant Proteins (genetics, metabolism)
• TCF Transcription Factors (metabolism)
• Transcription Factor 7-Like 2 Protein
• Transfection
• beta Catenin (metabolism)