The effect of thrombospondin on oral squamous carcinoma cell invasion of collagen.
BACKGROUND
Thrombospondin (TSP), a cell matrix protein, and transforming growth factor beta (TGF-beta), a growth regulatory protein, play roles in tumor progression. The purpose of this study was to investigate the effects of TSP and TGF-beta on tumor cell invasion.


METHODS
Tumor cell invasion assays were performed using a modified Boyden chamber apparatus with collagen-coated membranes. The KB oral carcinoma cell line was studied in serum-free media. Invasion was measured as the summation of the number of cells in five representative low-power fields (x 100) traversing the collagen barrier after a 3-hour incubation period. The effects of antibodies against TSP, TGF-beta and the cysteine-serine-valine-threonine-cysteine-glycine (CSVTCG)-specific TSP receptor were also evaluated.


RESULTS
TSP caused a dose-dependent stimulation of tumor cell invasion. Antibodies against TSP, its CSVTCG-specific receptor, and TGF-beta inhibited TSP-promoted invasion by 50% to 71%.


CONCLUSIONS
TSP and its CSVTCG-specific receptor promote KB cell invasion of collagen through the production and/or activation of TGF-beta.
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D018955:CD36 Antigens / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D002294:Carcinoma, Squamous Cell / Q000378:metabolism / Q000473:pathology*; D015815:Cell Adhesion Molecules / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D002452:Cell Count; D003094:Collagen / Q000187:drug effects* / Q000378:metabolism; D016895:Culture Media, Serum-Free; D015194:Diffusion Chambers, Culture; D018450:Disease Progression; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007074:Immunoglobulin G; D016023:Integrins / Q000187:drug effects / Q000276:immunology / Q000502:physiology; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000276:immunology / Q000494:pharmacology*; D008567:Membranes, Artificial; D008858:Microscopy, Phase-Contrast; D009062:Mouth Neoplasms / Q000378:metabolism / Q000473:pathology*; D009361:Neoplasm Invasiveness; D011076:Polycarboxylate Cement; D019699:Thrombospondins; D016212:Transforming Growth Factor beta / Q000276:immunology / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D018955:CD36 Antigens; D015815:Cell Adhesion Molecules; D016895:Culture Media, Serum-Free; D007074:Immunoglobulin G; D016023:Integrins; D008562:Membrane Glycoproteins; D008567:Membranes, Artificial; D011076:Polycarboxylate Cement; D019699:Thrombospondins; D016212:Transforming Growth Factor beta; C005506:polycarbonate; D003094:Collagen