TCC Cell Lines Research Articles

Bacillus Calmette-Guerin Abrogates in Vitro Invasion and Motility of Human Bladder Tumor Cells via Fibronectin Interaction

Intravesical bacillus Calmette-Guerin (BCG) has been shown to be an effective treatment for superficial transitional cell carcinoma of the bladder (TCC). The mechanisms by which BCG limits tumor cell activity have thus far been unclear.We investigated the interaction between BCG and invasive human TCC cell line EJ in an in vitro invasion assay. We observed that BCG inhibited the invasion of EJ cells through an artificial basement membrane. In terms of the steps involved in tumor cell invasion, i.e. attachment, proteolysis, and motility, BCG was found to limit tumor cell motility. Attachment and proliferation of tumor cells were not affected by BCG.The effects of BCG on tumor cell migration were mediated by fibronectin (FN), a basement membrane glycoprotein component. Abrogation of BCG-FN-tumor cell interactions with anti-FN antibodies eliminated the ability of BCG to block tumor cell invasion. Fibronectin appears to link BCG and tumor cells via independent FN binding receptors to separate domains of the FN molecule.The molecular mechanism by which BCG may limit tumor cell motility may be its ability to protect against the formation of specific FN sequences as a result of protease cathepsin B digestion. A 31kD and 27kD FN band were absent from purified or tumor cell associated cathepsin B digestion when incubated in the presence of BCG, but present in the absence of BCG. Furthermore when purified from SDS polyacrylamide gel electrophoresis, the fragments were shown to have motility stimulating activity for the invasive EJ cells.These findings suggest that BCG functions as a potent inhibitor of tumor cell invasion. We conclude that BCG-fibronectin-tumor cell interactions may have a direct influence on the invasive mechanisms, such as motility, of tumor cells.

Monoclonal antibodies to antigens associated with transitional cell carcinoma of the human urinary bladder. II. Identification of the cellular target structures by immunoprecipitation and SDS-PAGE analysis.

The cellular target structures for six monoclonal antibodies raised against cultured human bladder carcinoma cells (TCC) were investigated. The specificities of these antibodies when tested against a large panel of cells have been described in the companion paper. Radiolabeled cell lysates were precipitated with the different monoclonal antibodies bound to protein A (Staphylococcus aureus) on a matrix of Sepharose beads. The precipitates were separated by sodium dodecyl sulfate- gel electrophoresis (SDS-PAGE) and analyzed by autoradiography. The antibodies 4B5, 7E9, and 14B11 have previously been found to react in a similar way with TCC-targets and some non-TCC tumor cells, but not with normal urothelial cells or cells of hematopoietic origin. When tested with lysates of a TCC-cell line (TCCSuP) a strong 92K band and a weak 23K band were precipitated with any one of these antibodies. These polypeptides were expressed on the cell surface and were not linked by disulfide bonds. Depletion experiments confirmed that the three antibodies recognized the same antigens. Another antibody (4E8) probably directed to a differentiation antigen present on both urothelial and melanoma cells detected two high molecular polypeptides, 190K and 170K. Antibodies from the S2C6 hybridoma, which displayed a distinct dual specificity for TCC- targets and for malignant or transformed cells of B cell origin, precipitated a 50K component from extracts of either TCC- or B cell-derived cell lines. Antibodies produced by the S2A9 hybridoma were shown to bind to a framework epitope of the HLA-A, B, C heavy chain.

Lectins as Probes for Identification of Tumor-Associated Antigens on Urothelial and Colonic Carcinoma Cell Lines

In the search for tumor-associated antigens, seven lec-tins were used to investigate the cellular distribution of membrane-associated glycoproteins on a panel of human cells derived from tumor or normal tissues. Surface labelled lysates of the different cells were precipitated with the lectins and the precipitates were separated on SDS-PAGE. Comparison of the autoradiographic patterns revealed that a La-reactive 115K glycopeptide (gp 115) was present on transitional-cell carcinoma cells of the urinary bladder, on two spontaneously transformed urothelial cell lines and on a melanoma cell line. Gp 115 was absent from a non-transformed urothelial cell line, a squamous bladder carcinoma line and five unrelated cell lines of miscellaneous tissue origin. When precipitation was performed with a rabbit antiserum raised against the La-reactive components of a TCC cell line the same distribution of gp 115 was observed. From Helix pomatia hemagglutinin (HP) precipitates a 150K glycopolypeptide co-migrating with a previously described HP-reactive differentiation antigen associated with human T cells was present on one of the urothelial cell lines and on a colon carcinoma cell line. When different extracts depleted of ConA binding glycopeptides were compared, a group of three antigens (32K, 35K and 40K) were identified in the extracts of the colon carcinoma cell line, HT29. These antigens were shared by two other colon carcinoma cell lines but were absent from the unrelated cells of our panel. Furthermore, an extensively absorbed rabbit anti-HT29 serum specifically precipitated one of these antigens (35K) from the three colon cell lines.

Lectins as probes for identification of tumor-associated antigens on urothelial and colonic carcinoma cell lines.

In the search for tumor-associated antigens, seven lectins were used to investigate the cellular distribution of membrane-associated glycoproteins on a panel of human cells derived from tumor or normal tissues. Surface labelled lysates of the different cells were precipitated with the lectins and the precipitates were separated on SDS-PAGE. Comparison of the autoradiographic patterns revealed that a La-reactive 115K glycopeptide (gp 115) was present on transitional-cell carcinoma cells of the urinary bladder, on two spontaneously transformed urothelial cell lines and on a melanoma cell line. Gp 115 was absent from a non-transformed urothelial cell line, a squamous bladder carcinoma line and five unrelated cell lines of miscellaneous tissue origin. When precipitation was performed with a rabbit antiserum raised against the La-reactive components of a TCC cell line the same distribution of gp 115 was observed. From Helix pomatia hemagglutinin (HP) precipitates a 150K glycopolypeptide co-migrating with a previously described HP-reactive differentiation antigen associated with human T cells was present on one of the urothelial cell lines and on a colon carcinoma cell line. When different extracts depleted of ConA binding glycopeptides were compared, a group of three antigens (32K, 35K and 40K) were identified in the extracts of the colon carcinoma cell line, HT29. These antigens were shared by two other colon carcinoma cell lines but were absent from the unrelated cells of our panel. Furthermore, an extensively absorbed rabbit anti-HT29 serum specifically precipitated one of these antigens (35K) from the three colon cell lines.