TY - JOUR
T1 - Desmoplakin expression and distribution in cultured rat bladder epithelial cells of varying tumorigenic potential
AU - Green, Kathleen J.
AU - Stappenbeck, Thaddeus S.
AU - Noguchi, Sumio
AU - Oyasu, Ryoichi
AU - Nilles, Laura A.
N1 - Funding Information:
The authors are grateful to Dr. A. Staehelin for the polyclonal antibody directed against bovine DP, and to Dr. T.-T. Sun for the AEl and AE2 monoclonals. Thanks go also to those providing cell lines: Drs. M. Johnson and C. Reznikoff (RBE-8), Dr. S. Cohen (AY34), Dr. C. Y. Yang (R-4909), and Dr. B. Pauli (RBTCC-8). We are also very grateful for the technical expertise of Walter Glowgowski in preparing specimens for EM and preparation of figures. This work was supported in large part by Grant 2432 to K.G. from the Council for Tobacco Research, U.S.A., Inc. Additional support was provided by NIH HD24430 (K.G.), a March of Dimes Basil O’Connor Starter Scholar Award (K.G.), and NIH CA14649 (R.O.).
PY - 1991/3
Y1 - 1991/3
N2 - The expression and distribution of the desmosomal plaque proteins, desmoplakins (DPs) I and II, were studied in nontumorigenic (RBE-8) and a series of tumorigenic (AY34, R-4909, SS-24B, RBTCC-8, and 804G) rat bladder epithelial cell lines. These cell lines ranged from slow-growing papillary transitional cells (AY34) to rapidly metastatic carcinoma cells (RBTCC-8). DPs I and II were shown by immunoblotting and Northern analysis to be present in nontumorigenic RBE-8 cells as well as in all of the tumorigenic cell lines, albeit in differing amounts. Immunofluorescence microscopy revealed striking differences in DP distribution, corresponding in general with increases in tumorigenic potential. Whereas DPs of normal RBE-8 cells and less tumorigenic AY34 cells were localized predominantly at cell interfaces, the more tumorigenic lines exhibited a high proportion of DP in the form of cytoplasmic dots, a distribution reminiscent of that seen in epithelial cells maintained in low levels of extracellular calcium. In 804G cells, which represented the most extreme example of this phenomenon, the majority of DPs were organized as cytoplasmic dots. Electron microscopy revealed intermediate filament (IF)-associated spots in the cytoplasm as well as an elaborate array of IF-associated plaques at the cell-substratum interface. The IF-associated spots in the cytoplasm reacted with anti-DP antibody in immunogold labeling experiments while those at the cell-substratum did not react. In more dense cultures of 804G cells, certain cells stratified and expressed increased amounts of DP followed by the induction of new keratins including those of the skin type. Decreasing extracellular calcium resulted in a rearrangement of DP in each cell line; staining at cell-cell interfaces disappeared and was replaced with a pattern of cytoplasmic dots. These results demonstrate a possible relationship between desmosome assembly and/or maintenance and tumorigenic potential.
AB - The expression and distribution of the desmosomal plaque proteins, desmoplakins (DPs) I and II, were studied in nontumorigenic (RBE-8) and a series of tumorigenic (AY34, R-4909, SS-24B, RBTCC-8, and 804G) rat bladder epithelial cell lines. These cell lines ranged from slow-growing papillary transitional cells (AY34) to rapidly metastatic carcinoma cells (RBTCC-8). DPs I and II were shown by immunoblotting and Northern analysis to be present in nontumorigenic RBE-8 cells as well as in all of the tumorigenic cell lines, albeit in differing amounts. Immunofluorescence microscopy revealed striking differences in DP distribution, corresponding in general with increases in tumorigenic potential. Whereas DPs of normal RBE-8 cells and less tumorigenic AY34 cells were localized predominantly at cell interfaces, the more tumorigenic lines exhibited a high proportion of DP in the form of cytoplasmic dots, a distribution reminiscent of that seen in epithelial cells maintained in low levels of extracellular calcium. In 804G cells, which represented the most extreme example of this phenomenon, the majority of DPs were organized as cytoplasmic dots. Electron microscopy revealed intermediate filament (IF)-associated spots in the cytoplasm as well as an elaborate array of IF-associated plaques at the cell-substratum interface. The IF-associated spots in the cytoplasm reacted with anti-DP antibody in immunogold labeling experiments while those at the cell-substratum did not react. In more dense cultures of 804G cells, certain cells stratified and expressed increased amounts of DP followed by the induction of new keratins including those of the skin type. Decreasing extracellular calcium resulted in a rearrangement of DP in each cell line; staining at cell-cell interfaces disappeared and was replaced with a pattern of cytoplasmic dots. These results demonstrate a possible relationship between desmosome assembly and/or maintenance and tumorigenic potential.
UR - http://www.scopus.com/inward/record.url?scp=0026080785&partnerID=8YFLogxK
U2 - 10.1016/0014-4827(91)90547-8
DO - 10.1016/0014-4827(91)90547-8
M3 - Article
C2 - 1995289
AN - SCOPUS:0026080785
VL - 193
SP - 134
EP - 143
JO - Experimental Cell Research
JF - Experimental Cell Research
SN - 0014-4827
IS - 1
ER -