Identification of the HeLa tumor-associated antigen, p75/150, as intestinal alkaline phosphatase and evidence for its transcriptional regulation.
Prior studies identified a cell-surface antigen, p75/150, that exclusively associated with the tumorigenic phenotype of the HeLa parent and the tumorigenic phenotype of the HeLa parent and the tumorigenic segregants of suppressed, nontumorigenic HeLa x human fibroblast cell hybrids. Candidate p75/150 cDNA clones were isolated from a D98/AH.2 (HeLa) cDNA library using oligonucleotide probes derived from p75/150 partial peptide sequence data. A data base search revealed close similarity of p75/150 with intestinal alkaline phosphatase (IAP) [Berger, J., Garantini, E., Hua, J. C. & Udenfriend, S. (1987) Proc. Natl. Acad. Sci. USA 84, 695-698]. We demonstrate that p75/150 is identical to HeLa IAP by the following criteria: (i) 47/49 amino acid identity of p75 peptide sequence with IAP, (ii) restriction maps for the p75/150 candidate cDNA clone and IAP are identical, (iii) partial DNA sequence analysis of p75/150 candidate cDNA clones revealed complete nucleotide identity with IAP, except for a single nucleotide substitution in the 5' untranslated region, (iv) transfection of a p75/150 cDNA expression vector into the nontumorigenic hybrid, CGL1, yielded p75/150 antibody-positive transfectants that also expressed partially heat-resistant alkaline phosphatase activity. Northern blot analysis demonstrated that high levels of HeLa IAP mRNA were expressed in D98/AH.2 and the tumorigenic segregant CGL4; however, no mRNA was detected in CGL1. Nuclear run-on analyses indicate that HeLa IAP mRNA expression in the HeLa x fibroblast hybrids is regulated at the level of transcription initiation. Furthermore, evidence is discussed supporting the involvement of a chromosome 11 tumor suppressor locus in the regulation of HeLa IAP gene expression.
Latham
K M
KM
Department of Microbiology and Molecular Genetics, University of California-Irvine, College of Medicine 92717.
Stanbridge
E J
EJ
D000199:Actins / Q000235:genetics; D000469:Alkaline Phosphatase / Q000235:genetics* / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000235:genetics*; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D058851:GPI-Linked Proteins; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D005822:Genetic Vectors; D006367:HeLa Cells / Q000201:enzymology / Q000276:immunology; D006801:Humans; D006822:Hybrid Cells / Q000201:enzymology; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D009876:Operon; D014158:Transcription, Genetic; D014162:Transfection
D000199:Actins; D000951:Antigens, Neoplasm; D058851:GPI-Linked Proteins; D015345:Oligonucleotide Probes; C063088:ALPI protein, human; D000469:Alkaline Phosphatase