Autocrine stimulation of AR4-2J rat pancreatic tumor cell growth by glycine-extended gastrin.
Glycine-extended gastrin (gastrin-Gly) stimulates proliferation of AR4-2J pancreatic tumor cell line through a specific receptor, different from the gastrin-cholecystokinin B receptor. Our purpose was to determine whether AR4-2J cells produced gastrin-Gly and then whether the peptide was involved in an autocrine loop. First, proliferation of AR4-2J cells in serum-free medium was inhibited by a gastrin anti-sense oligodeoxynucleotide phosphorothioate and by antibodies specific for gastrin-Gly. In contrast, antibodies specific for alpha-amidated gastrin were without effect. By using RT-PCR, we have shown that AR4-2J cells expressed gastrin mRNA. The presence of gastrin-Gly, but not alpha-amidated gastrin, in serum-free media was detected by radioimmunoanalysis. Gel chromatography revealed that the predominant molecular forms secreted were glycine-extended gastrin-34 and gastrin- 17. Furthermore, epidermal growth factor (EGF), a stimulator of gastrin gene transcription, modulates gastrin-Gly secretion by AR4-2J. These data together suggest that gastrin-Gly is an autocrine growth factor for AR4-2J cells and that it participates with EGF in the regulation of AR4-2J-cell proliferation.
Nègre
F
F
Groupe de Recherche de Biologie et Pathologie Digestive, Institut National de la Santé et de la Recherche Médicale, Unité 151, Toulouse, France.
Fagot-Revurat
P
P
Bouisson
M
M
Rehfeld
J F
JF
Vaysse
N
N
Pradayrol
L
L
D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D004815:Epidermal Growth Factor / Q000494:pharmacology; D005755:Gastrins / Q000096:biosynthesis / Q000378:metabolism / Q000502:physiology*; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D016376:Oligonucleotides, Antisense / Q000494:pharmacology; D010190:Pancreatic Neoplasms / Q000378:metabolism* / Q000473:pathology*; D051381:Rats; D013268:Stimulation, Chemical; D013873:Thionucleotides / Q000494:pharmacology; D014407:Tumor Cells, Cultured / Q000187:drug effects
D000906:Antibodies; D005755:Gastrins; D016376:Oligonucleotides, Antisense; D013873:Thionucleotides; C086854:glycine-extended gastrin 17; D004815:Epidermal Growth Factor