Studies on 17-1A antigen gene regulation in nonexpressing A549 and A431 cells, as compared to expressing pancreatic carcinoma (Capan 2) cells, reveal a complex mechanism of repression of this gene.
Elements controlling high expression of the 17-1A antigen gene in pancreatic carcinoma cells (Capan 2) reside within the two regions: proximal (-193 to +3) and distal (-877 to -518). We demonstrate here that some factors present in nuclear extracts from nonexpressing cells bind specifically to the control elements, important for gene expression. Our results suggest that nonexpressing cells may either lack at least one of the factors necessary for activation or may contain their modified forms. A major difference between expressing and nonexpressing cells was found in the region containing core enhancer sequence. Moreover, nonexpressing cells display a complex pattern of DNA-protein interactions in this region, suggesting that these cells contain factors acting negatively mainly on the enhancer sequence. Our results however, indicate that the mechanism of repression is much more complicated than expected.
Siemieniako
B
B
Institute of Human Genetics, Polish Academy of Sciences, Poznań.
Wiland
E
E
Trzeciak
W H
WH
D000951:Antigens, Neoplasm / Q000096:biosynthesis / Q000235:genetics*; D001483:Base Sequence; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D004273:DNA, Neoplasm / Q000235:genetics; D004268:DNA-Binding Proteins / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D015972:Gene Expression Regulation, Neoplastic; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000378:metabolism; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000473:pathology; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D012334:RNA, Neoplasm / Q000096:biosynthesis; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured / Q000378:metabolism
D000951:Antigens, Neoplasm; D004273:DNA, Neoplasm; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; C050928:carcinoma-associated antigen 17-1A