The c-erbA beta thyroid hormone receptor. Expression and cDNA sequence analysis of the hormone-binding domain in human cancer cell lines.
The human c-erbA beta protooncogene encodes a thyroid hormone receptor (comprising a hormone-binding domain and a DNA-binding domain) which modulates expression of specific genes, such as cell differentiation genes. Using the reverse transcription and polymerase chain reaction (RT-PCR) assay, significant expression of the c-erbA beta gene was detected in the SiHa, CaSki, HeLa cervical carcinoma; Hep3B, PLC/PRF/5, Mahlavu hepatocellular carcinoma; HT-1080 fibrosarcoma cell lines; as well as in normal MRC-5 embryo lung and FS-4 foreskin fibroblast cell lines. However, the Molt-4 leukaemia and Raji Burkitt's lymphoma cell lines exhibited very low levels of c-erbA beta expression. Single-strand conformation polymorphism analysis and direct sequencing of PCR products of the c-erbA beta hormone-binding domain cDNAs of these cell lines revealed identical sequences, but differed from the published human placental c-erbA beta sequence by five single base disparities. Sequencing of an aberrant fragment fortuitously amplified from the HT-1080 cDNA library demonstrated concordance with the cDNA of pregnancy-specific glycoprotein 4, which is related to the tumour marker, carcinoembryonic antigen.
Chow
V T
VT
Department of Microbiology, Faculty of Medicine, National University of Singapore, Kent Ridge.
Lim
S S
SS
Tock
E P
EP
D001483:Base Sequence; D004247:DNA / Q000378:metabolism; D018076:DNA, Complementary / Q000032:analysis; D005347:Fibroblasts; D005786:Gene Expression Regulation; D006801:Humans; D008168:Lung / Q000196:embryology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011257:Pregnancy Proteins / Q000235:genetics; D011485:Protein Binding; D011988:Receptors, Thyroid Hormone / Q000235:genetics*; D014407:Tumor Cells, Cultured
D018076:DNA, Complementary; D011257:Pregnancy Proteins; D011988:Receptors, Thyroid Hormone; D004247:DNA