Truncated DCC reduces N-cadherin/catenin expression and calcium-dependent cell adhesion in neuroblastoma cells.
The deleted in colorectal cancer (DCC) protein is important in the pathway guidance of cells and cell processes during neural development, and DCC has also been implicated in the aberrant cellular migrations of neuroblastoma dissemination. We attempted to further define DCC protein function by the overexpression of full-length and truncated DCC constructs in a human neuroblastoma cell line. Overexpression of the truncated DCC protein resulted in a less epithelioid morphology. This was accompanied by decreases in expression of N-cadherin and alpha- and beta-catenin by immunoblot and Northern blot analysis. Levels of desmoglein were relatively less affected, whereas endogenous DCC protein levels were increased in the truncated transfectants. N-cadherin immunofluorescence was consistent with the immunoblot studies and localized the protein to the cytoplasm and sites of cell-cell contact. Cell aggregation studies demonstrated diminished calcium-dependent aggregation in the truncated transfectants. In conclusion, overexpression of a truncated DCC protein in neuroblastoma cells resulted in the loss of an epithelioid morphology, diminished expression of N-cadherin and alpha- and beta-catenin, and diminished calcium-dependent cell adhesion. These studies provide the first evidence of an apparent functional link between DCC and N-cadherin/catenin-dependent cell adhesion.
Reyes-Múgica
M
M
Department of Pathology, Yale University School of Medicine and West Haven Veterans Administration Medical Center, New Haven, Connecticut 06520-8023,USA. miguel.reyes@yale.edu
Meyerhardt
J A
JA
Rzasa
J
J
Rimm
D L
DL
Johnson
K R
KR
Wheelock
M J
MJ
Reale
M A
MA
D015820:Cadherins / Q000235:genetics*; D002118:Calcium / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000235:genetics* / Q000378:metabolism*; D002449:Cell Aggregation; D015179:Colorectal Neoplasms / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000235:genetics*; D000075389:DCC Receptor; D051182:Desmogleins; D051180:Desmoplakins; D015972:Gene Expression Regulation, Neoplastic; D016163:Genes, DCC; D006801:Humans; D009447:Neuroblastoma; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins / Q000378:metabolism; D017384:Sequence Deletion; D015534:Trans-Activators; D014162:Transfection; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins; D051178:alpha Catenin; D051176:beta Catenin
C495273:CTNNA1 protein, human; C495270:CTNNB1 protein, human; D015820:Cadherins; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D000075389:DCC Receptor; C501909:DCC protein, human; D051182:Desmogleins; D051180:Desmoplakins; D011956:Receptors, Cell Surface; D011994:Recombinant Proteins; D015534:Trans-Activators; D025521:Tumor Suppressor Proteins; D051178:alpha Catenin; D051176:beta Catenin; D002118:Calcium