title: CCK2 receptor expression transforms non-tumorigenic human NCM356 colonic epithelial cells into tumor forming cells.
abstract: Expression of gastrin and cholecystokinin 2 (CCK(2)) receptor splice variants (CCK(2)R and CCK(2i4sv)R) are upregulated in human colonic adenomas where they are thought to contribute to tumor growth and progression. To determine the effects of ectopic CCK(2) receptor variant expression on colonic epithelial cell growth in vitro and in vivo, we employed the non-tumorigenic colonic epithelial cell line, NCM356. Receptor expression was induced using a retroviral expression vector containing cDNAs for either CCK(2i4sv)R or CCK(2)R. RT-PCR and intracellular Ca(2+) ([Ca(2+)](i)) imaging of RIE/CCK(2)R cells treated with conditioned media (CM) from NCM356 revealed that NCM356 cells express gastrin mRNA and secrete endogenous, biologically active peptide. NCM356 cells expressing either CCK(2)R or CCK(2i4sv)R (71 and 81 fmol/mg, respectively) grew faster in vitro, and exhibited an increase in basal levels of phosphorylated ERK (pERK), compared with vector. CCK(2) receptor selective antagonist, YM022, partially inhibited the growth of both receptor-expressing NCM356 cells, but not the control cells. Inhibitors of mitogen activated protein kinase pathway (MEK/ERK) or protein kinase C (PKC) isozymes partially inhibited the elevated levels of basal pERK and in vitro growth of receptor-expressing cells. Vector-NCM356 cells did not form tumors in nude mice, whereas, either CCK(2) receptor-expressing cells formed large tumors. Autocrine activation CCK(2) receptor variants are sufficient to increase in vitro growth and tumorigenicity of non-transformed NCM356 colon epithelial cells through a pathway involving PKC and the MEK/ERK axis. These findings support the hypothesis that expression of gastrin and its receptors in human colonic adenomas contributes to tumor growth and progression.
authors.affiliation: Department of Surgery, University of Texas Medical Branch, Galveston, Texas, USA.
authors.forename: Celia
authors.initials: C
authors.lastname: Chao
authors.forename: Xueliang
authors.initials: X
authors.lastname: Han
authors.forename: Kirk
authors.initials: K
authors.lastname: Ives
authors.forename: Jeseong
authors.initials: J
authors.lastname: Park
authors.forename: Andrey A
authors.initials: AA
authors.lastname: Kolokoltsov
authors.forename: Robert A
authors.initials: RA
authors.lastname: Davey
authors.forename: Mary P
authors.initials: MP
authors.lastname: Moyer
authors.forename: Mark R
authors.initials: MR
authors.lastname: Hellmich
mesh_terms: D000236:Adenoma / Q000473:pathology; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002277:Carcinoma / Q000235:genetics; D018929:Cell Culture Techniques / Q000379:methods; D002455:Cell Division / Q000235:genetics; D003106:Colon / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D015179:Colorectal Neoplasms / Q000235:genetics / Q000473:pathology*; D017931:DNA Primers; D018450:Disease Progression; D005755:Gastrins / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D006801:Humans; D007413:Intestinal Mucosa / Q000378:metabolism / Q000473:pathology / Q000502:physiology*; D051379:Mice; D009154:Mutation; D009367:Neoplasm Staging; D043887:Receptor, Cholecystokinin B / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D005755:Gastrins; D043887:Receptor, Cholecystokinin B; D002118:Calcium
references.citation: J Clin Invest. 2000 Aug;106(4):533-9
references.pmid: 10953028
references.citation: Ann Intern Med. 1989 Nov 1;111(9):738-42
references.pmid: 2802432
references.citation: J Biol Chem. 2005 Sep 30;280(39):33368-73
references.pmid: 16079138
references.citation: Int J Cancer. 1999 May 5;81(3):376-86
references.pmid: 10209952
references.citation: Ann N Y Acad Sci. 2004 Apr;1014:97-109
references.pmid: 15153424
references.citation: Digestion. 1999;60(3):210-5
references.pmid: 10343134
references.citation: Cancer Lett. 2007 Jul 8;252(1):19-35
references.pmid: 17188424
references.citation: Gastroenterology. 1993 Jul;105(1):22-30
references.pmid: 8514038
references.citation: Gastroenterology. 1998 Aug;115(2):275-80
references.pmid: 9679032
references.citation: Proc Natl Acad Sci U S A. 1997 Jan 21;94(2):751-6
references.pmid: 9012857
references.citation: Biochim Biophys Acta. 2004 Jul 6;1704(1):1-10
references.pmid: 15238241
references.citation: Cell. 2000 Jan 7;100(1):57-70
references.pmid: 10647931
references.citation: Pharmacol Rev. 1999 Dec;51(4):745-81
references.pmid: 10581329
references.citation: Oncogene. 2007 Feb 15;26(7):1013-9
references.pmid: 16909104
references.citation: Curr Opin Pharmacol. 2007 Dec;7(6):583-92
references.pmid: 17997137
references.citation: Cell. 1996 Oct 18;87(2):159-70
references.pmid: 8861899
references.citation: Nat Rev Genet. 2002 Jun;3(6):415-28
references.pmid: 12042769
references.citation: J Surg Res. 2005 Dec;129(2):313-21
references.pmid: 16051276
references.citation: Gut. 2000 Dec;47(6):820-4
references.pmid: 11076881
references.citation: Gut. 1997 Sep;41(3):330-2
references.pmid: 9378387
references.citation: Cancer Lett. 2005 May 10;222(1):95-105
references.pmid: 15837546
references.citation: Clin Cancer Res. 2000 Dec;6(12):4719-24
references.pmid: 11156225
references.citation: FEBS Lett. 2001 May 4;496(1):25-30
references.pmid: 11343700
references.citation: Cardiovasc Hematol Disord Drug Targets. 2006 Jun;6(2):85-100
references.pmid: 16787194
references.citation: Nat Rev Mol Cell Biol. 2008 Jul;9(7):517-31
references.pmid: 18568040
references.citation: J Biol Chem. 2000 Oct 13;275(41):32122-8
references.pmid: 10913157
references.citation: Am J Surg. 1995 Feb;169(2):190-5; discussion 195-6
references.pmid: 7840378
references.citation: Am J Physiol Gastrointest Liver Physiol. 2003 Jan;284(1):G75-84
references.pmid: 12488236
references.citation: J Biol Chem. 2002 Dec 13;277(50):48755-63
references.pmid: 12239223
references.citation: Nat Rev Cancer. 2001 Oct;1(1):55-67
references.pmid: 11900252
references.citation: Annu Rev Physiol. 2001;63:119-39
references.pmid: 11181951
references.citation: Cancer Res. 2001 Jan 15;61(2):625-31
references.pmid: 11212260
references.citation: Am J Physiol. 1997 Oct;273(4):G891-8
references.pmid: 9357832
references.citation: Br J Cancer. 2002 Aug 27;87(5):567-73
references.pmid: 12189558
references.citation: J Virol. 2005 Jan;79(2):756-63
references.pmid: 15613303
references.citation: Am J Physiol. 1999 Jun;276(6):G1363-72
references.pmid: 10362639
references.citation: Br J Cancer. 2006 Apr 24;94(8):1107-15
references.pmid: 16622436