Characterization of gastrins and their receptor in solid human gastric adenocarcinomas

TY - JOUR

T1 - Characterization of gastrins and their receptor in solid human gastric adenocarcinomas

AU - Goetze, Jens Peter

AU - Eiland, Signe

AU - Svendsen, Lars Bo

AU - Vainer, Ben

AU - Hannibal, Jens

AU - Rehfeld, Jens Frederik

PY - 2013/6

Y1 - 2013/6

N2 - Objective. The gastrin and the gastrin/CCK-B receptor genes are co-expressed in several carcinomas. The primary translational product, progastrin, however, is processed to several peptides of which only those that are α-amidated at their C-terminus are receptor ligands. So far, characterization of the progastrin-derived peptides in gastric cancer has not been reported. The authors therefore examined the molecular nature of gastrin and its receptor in human gastric carcinomas. Materials and methods. Twenty patients with adenocarcinoma underwent partial or total gastrectomy. In samples from each carcinoma, gastrin peptides were characterized, using a library of sequence-specific immunoassays. Expression was also demonstrated by immunohistochemistry. In addition, the gastrin and gastrin/CCK-B receptor gene expression was quantitated using real-time PCR, and the receptor protein demonstrated by western blotting. Results. α-Amidated gastrins were detectable in 16 of 20 carcinomas (median concentration 2.1 pmol/g tissue; range 0-386 pmol/g tissue). The tissue concentrations correlated closely to the gastrin mRNA contents (r = 0.75, p < 0.0001). Moreover, progastrin and non-amidated processing intermediates, including glycine-extended gastrins, were detected in 19 carcinomas. Immunohistochemistry corroborated gastrin expression in carcinoma cells. Chromatography revealed extensive progastrin processing with α-amidated gastrin-34 and -17 (tyrosyl-sulfated as well as non-sulfated) as major products. Finally, gastrin/CCK-B receptor mRNA and protein were detected in all tumors. Conclusions. The results show that the elements for a local loop of α-amidated gastrins and their receptor are detectable in 80% of human gastric adenocarcinomas. Therefore, the results support the contention that locally expressed gastrin may be involved in the tumorigenesis of gastric adenocarcinomas.

AB - Objective. The gastrin and the gastrin/CCK-B receptor genes are co-expressed in several carcinomas. The primary translational product, progastrin, however, is processed to several peptides of which only those that are α-amidated at their C-terminus are receptor ligands. So far, characterization of the progastrin-derived peptides in gastric cancer has not been reported. The authors therefore examined the molecular nature of gastrin and its receptor in human gastric carcinomas. Materials and methods. Twenty patients with adenocarcinoma underwent partial or total gastrectomy. In samples from each carcinoma, gastrin peptides were characterized, using a library of sequence-specific immunoassays. Expression was also demonstrated by immunohistochemistry. In addition, the gastrin and gastrin/CCK-B receptor gene expression was quantitated using real-time PCR, and the receptor protein demonstrated by western blotting. Results. α-Amidated gastrins were detectable in 16 of 20 carcinomas (median concentration 2.1 pmol/g tissue; range 0-386 pmol/g tissue). The tissue concentrations correlated closely to the gastrin mRNA contents (r = 0.75, p < 0.0001). Moreover, progastrin and non-amidated processing intermediates, including glycine-extended gastrins, were detected in 19 carcinomas. Immunohistochemistry corroborated gastrin expression in carcinoma cells. Chromatography revealed extensive progastrin processing with α-amidated gastrin-34 and -17 (tyrosyl-sulfated as well as non-sulfated) as major products. Finally, gastrin/CCK-B receptor mRNA and protein were detected in all tumors. Conclusions. The results show that the elements for a local loop of α-amidated gastrins and their receptor are detectable in 80% of human gastric adenocarcinomas. Therefore, the results support the contention that locally expressed gastrin may be involved in the tumorigenesis of gastric adenocarcinomas.

KW - Adenocarcinoma

KW - Adult

KW - Aged

KW - Aged, 80 and over

KW - Female

KW - Gastrins

KW - Gene Expression

KW - Humans

KW - Male

KW - Middle Aged

KW - Protein Precursors

KW - RNA, Messenger

KW - Receptor, Cholecystokinin B

KW - Stomach Neoplasms

U2 - 10.3109/00365521.2013.783101

DO - 10.3109/00365521.2013.783101

M3 - Journal article

C2 - 23544442

SN - 0085-5928

VL - 48

SP - 688

EP - 695

JO - Scandinavian Journal of Gastroenterology

JF - Scandinavian Journal of Gastroenterology

IS - 6

ER -