Mutated epithelial cadherin is associated with increased tumorigenicity and loss of adhesion and of responsiveness to the motogenic trefoil factor 2 in colon carcinoma cells.
Epithelial (E)-cadherin and its associated cytoplasmic proteins (alpha-, beta-, and gamma-catenins) are important mediators of epithelial cell-cell adhesion and intracellular signaling. Much evidence exists suggesting a tumor/invasion suppressor role for E-cadherin, and loss of expression, as well as mutations, has been described in a number of epithelial cancers. To investigate whether E-cadherin gene (CDH1) mutations occur in colorectal cancer, we screened 49 human colon carcinoma cell lines from 43 patients by single-strand conformation polymorphism (SSCP) analysis and direct sequencing. In addition to silent changes, polymorphisms, and intronic variants in a number of the cell lines, we detected frameshift single-base deletions in repeat regions of exon 3 (codons 120 and 126) causing premature truncations at codon 216 in four replication-error-positive (RER+) cell lines (LS174T, HCT116, GP2d, and GP5d) derived from 3 patients. In LS174T such a mutation inevitably contributes to its lack of E-cadherin protein expression and function. Transfection of full-length E-cadherin cDNA into LS174T cells enhanced intercellular adhesion, induced differentiation, retarded proliferation, inhibited tumorigenicity, and restored responsiveness to the migratory effects induced by the motogenic trefoil factor 2 (human spasmolytic polypeptide). These results indicate that, although inactivating E-cadherin mutations occur relatively infrequently in colorectal cancer cell lines overall (3/43 = 7%), they are more common in cells with an RER+ phenotype (3/10 = 30%) and may contribute to the dysfunction of the E-cadherin-catenin-mediated adhesion/signaling system commonly seen in these tumors. These results also indicate that normal E-cadherin-mediated cell adhesion can restore the ability of colonic tumor cells to respond to trefoil factor 2.
Efstathiou
J A
JA
Cancer and Immunogenetics Laboratory, Imperial Cancer Research Fund, Institute of Molecular Medicine, John Radcliffe Hospital, Oxford OX3 9DS, United Kingdom.
Liu
D
D
Wheeler
J M
JM
Kim
H C
HC
Beck
N E
NE
Ilyas
M
M
Karayiannakis
A J
AJ
Mortensen
N J
NJ
Kmiot
W
W
Playford
R J
RJ
Pignatelli
M
M
Bodmer
W F
WF
D000818:Animals; D020029:Base Pairing; D015820:Cadherins / Q000235:genetics* / Q000502:physiology; D002448:Cell Adhesion / Q000187:drug effects; D003110:Colonic Neoplasms / Q000235:genetics* / Q000473:pathology*; D015179:Colorectal Neoplasms; D004261:DNA Replication / Q000235:genetics; D005091:Exons; D005260:Female; D016368:Frameshift Mutation; D014644:Genetic Variation; D006133:Growth Substances / Q000494:pharmacology*; D006801:Humans; D007438:Introns; D051379:Mice; D008819:Mice, Nude; D009077:Mucins; D009124:Muscle Proteins; D009154:Mutation; D009479:Neuropeptides; D010455:Peptides / Q000494:pharmacology*; D017354:Point Mutation; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D011994:Recombinant Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D014162:Transfection; D014183:Transplantation, Heterologous; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D014407:Tumor Cells, Cultured
D015820:Cadherins; D006133:Growth Substances; D009077:Mucins; D009124:Muscle Proteins; D009479:Neuropeptides; D010455:Peptides; D011994:Recombinant Proteins; C000604007:TFF2 protein, human; C099037:TFF3 protein, rat; C000604008:Tff2 protein, rat; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3