Cell adhesion regulates melanoma specific differentiation and interactions with the 3' region of the tyrosinase gene.
Decreased attachment to substratum has now been found to increase melanosome formation and cell-cell interaction in B16 melanoma. Since melanosome formation involves tyrosinase gene expression, we assayed for differential RNA expression by hybridization with probes from the distal ends of this gene, detecting unequal reactivity only with the 3' end probe. The same DNA showed binding of 2 nuclear proteins of 50 and 60 kd in unanchored cells, in contrast with a decreased binding of the 60 kd species, in nuclear extracts from attached cells. No comparable differences were detected with a gamma-actin DNA of identical length, suggesting that the changes observed are sequence-specific. Our studies suggest that the adhesion-mediated modulation of pigmentation in B16 melanoma correlates with differential macromolecular interactions with the 3' end of the tyrosinase gene.
Morasso
M I
MI
Centre of Microbiology and Cell Biology, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela.
Rieber
M S
MS
Gil
F
F
Rieber
M
M
D000818:Animals; D002448:Cell Adhesion; D002449:Cell Aggregation; D002454:Cell Differentiation; D002460:Cell Line; D004273:DNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D005353:Fibronectins; D015971:Gene Expression Regulation, Enzymologic; D015972:Gene Expression Regulation, Neoplastic; D008546:Melanoma, Experimental / Q000201:enzymology / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*; D051379:Mice; D014442:Monophenol Monooxygenase / Q000235:genetics*; D009687:Nuclear Proteins / Q000378:metabolism
D004273:DNA, Neoplasm; D005353:Fibronectins; D009687:Nuclear Proteins; D014442:Monophenol Monooxygenase