Transcription of the putative tumor suppressor gene HCCS1 requires binding of ETS-2 to its consensus near the transcription start site.
The hepatocellular carcinoma suppressor 1 (HCCS1) gene was identified by both positional cloning from a predominant region of loss of heterozygosity (17p13.3) in liver cancer and by functional screening for genes affecting cell proliferation in large-scale transfection assays. Its overexpression results in inhibition of cell proliferation in cell culture and tumor growth in nude mice. To understand its transcription regulation, the promoter architecture has been dissected in detail. The major start of transcription was mapped by primer extension to a C residue, 177 nucleotides upstream of the ATG codon. By assessing the promoter activity of a set of linker-scanning mutants of the minimal promoter (-60 to +148 region) in a transient transfection assay, we found that the +1 to + 40 region is critical to HCCS1 gene transcription, containing binding sites for transcription factors NF-kappaB (-21 to +7 and +40 to +26), p53 (+29 to +9) and ETS (+4 to +20 and +23 to +39). Biochemical and molecular analyses revealed that the ETS transcription factors ETS-2 and Elf-1 bind to the two ETS sites in situ and contribute significantly to the transcriptionally active state of the HCCS1 gene, while NF-kappaB, p53 and two other members of the ETS family (ETS-1 and NERF2) appear to play little role. Our observations provide insight into the mechanistic aspects of HCCS1 transcription regulation.
Zhu
Jing De
JD
Laboratory of Cancer Epigenetics and Gene Therapy, The State-Key Laboratory for Oncogenes and Related Genes, Shanghai Cancer Institute, Shanghai Jiaotong University, Shanghai, China. zhujingde@yahoo.com
Fei
Qi
Q
Wang
Peng
P
Lan
Fei
F
Mao
Da Qin
DQ
Zhang
Hong Yu
HY
Yao
Xue Biao
XB
D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D016384:Consensus Sequence; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000235:genetics / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D050787:Proto-Oncogene Protein c-ets-2 / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D024363:Transcription Initiation Site; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism; D033921:Vesicular Transport Proteins
C512897:ELF1 protein, human; C494069:ETS2 protein, human; D016328:NF-kappa B; D009687:Nuclear Proteins; D050787:Proto-Oncogene Protein c-ets-2; C495901:TP53 protein, human; D014157:Transcription Factors; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; C503307:VPS53 protein, human; D033921:Vesicular Transport Proteins