Oncogene expression cloning by retroviral transduction of adenovirus E1A-immortalized rat kidney RK3E cells: transformation of a host with epithelial features by c-MYC and the zinc finger protein GKLF.
The function of several known oncogenes is restricted to specific host cells in vitro, suggesting that new genes may be identified by using alternate hosts. RK3E cells exhibit characteristics of epithelia and are susceptible to transformation by the G protein RAS and the zinc finger protein GLI. Expression cloning identified the major transforming activities in squamous cell carcinoma cell lines as c-MYC and the zinc finger protein gut-enriched Kruppel-like factor (GKLF)/epithelial zinc finger. In oral squamous epithelium, GKLF expression was detected in the upper, differentiating cell layers. In dysplastic epithelium, expression was prominently increased and was detected diffusely throughout the entire epithelium, indicating that GKLF is misexpressed in the basal compartment early during tumor progression. The results demonstrate transformation of epithelioid cells to be a sensitive and specific assay for oncogenes activated during tumorigenesis in vivo, and identify GKLF as an oncogene that may function as a regulator of proliferation or differentiation in epithelia.
Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, 35294-3300, USA.
K W
KW
Foster
S
S
Ren
I D
ID
Louro
S M
SM
Lobo-Ruppert
P
P
McKie-Bell
W
W
Grizzle
M R
MR
Hayes
T R
TR
Broker
L T
LT
Chow
J M
JM
Ruppert
D017500:Adenovirus E1A Proteins / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D002472:Cell Transformation, Viral; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D004847:Epithelial Cells; D018628:Gene Dosage; D015870:Gene Expression; D015723:Gene Library; D005822:Genetic Vectors; D006801:Humans; D007668:Kidney / Q000166:cytology; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D008969:Molecular Sequence Data; D008979:Moloney murine leukemia virus; D015513:Oncogene Proteins / Q000235:genetics; D009857:Oncogenes; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics*; D051381:Rats; D015534:Trans-Activators; D014157:Transcription Factors / Q000235:genetics*; D014407:Tumor Cells, Cultured; D000071676:Zinc Finger Protein GLI1; D016335:Zinc Fingers
D017500:Adenovirus E1A Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C000715467:KLF4 protein, human; C000715469:Klf4 protein, rat; D000090062:Kruppel-Like Factor 4; D051741:Kruppel-Like Transcription Factors; D015513:Oncogene Proteins; D016271:Proto-Oncogene Proteins c-myc; D015534:Trans-Activators; D014157:Transcription Factors; D000071676:Zinc Finger Protein GLI1