Identification of E2F1 as a positive transcriptional regulator for delta-catenin.
delta-Catenin is upregulated in human carcinomas. However, little is known about the potential transcriptional factors that regulate delta-catenin expression in cancer. Using a human delta-catenin reporter system, we have screened several nuclear signaling modulators to test whether they can affect delta-catenin transcription. Among beta-catenin/LEF-1, Notch1, and E2F1, E2F1 dramatically increased delta-catenin-luciferase activities while beta-catenin/LEF-1 induced only a marginal increase. Rb suppressed the upregulation of delta-catenin-luciferase activities induced by E2F1 but did not interact with delta-catenin. RT-PCR and Western blot analyses in 4 different prostate cancer cell lines revealed that regulation of delta-catenin expression is controlled mainly at the transcriptional level. Interestingly, the effects of E2F1 on delta-catenin expression were observed only in human cancer cells expressing abundant endogenous delta-catenin. These studies identify E2F1 as a positive transcriptional regulator for delta-catenin, but further suggest the presence of strong negative regulator(s) for delta-catenin in prostate cancer cells with minimal endogenous delta-catenin expression.
Kim
Kwonseop
K
Department of Anatomy and Cell Biology, The Brody School of Medicine, East Carolina University, 600 Moye Street, Greenville, NC 27834, USA.
Oh
Minsoo
M
Ki
Hyunkyoung
H
Wang
Tao
T
Bareiss
Sonja
S
Fini
M Elizabeth
ME
Li
Dawei
D
Lu
Qun
Q
D051177:Catenins; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D045744:Cell Line, Tumor; D050687:E2F1 Transcription Factor / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008297:Male; D010750:Phosphoproteins / Q000378:metabolism*; D011471:Prostatic Neoplasms / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D015533:Transcriptional Activation; D000095002:Delta Catenin
D051177:Catenins; D015815:Cell Adhesion Molecules; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D010750:Phosphoproteins; D000095002:Delta Catenin