TY  - JOUR
AB  - BACKGROUND: Human T-cell leukemia virus type 1 (HTLV-1) is an oncogenic retrovirus etiologically associated with adult T-cell leukemia (ATL). The HTLV-1 bZIP factor (HBZ), which is encoded by minus strand of provirus, is expressed in all ATL cases and supports the proliferation of ATL cells. However, the precise mechanism of growth promoting activity of HBZ is poorly understood. RESULTS: In this study, we showed that HBZ suppressed C/EBP? signaling activation induced by either Tax or C/EBP?. As mechanisms of HBZ-mediated C/EBP? inhibition, we found that HBZ physically interacted with C/EBP? and diminished its DNA binding capacity. Luciferase and immunoprecipitation assays revealed that HBZ repressed C/EBP? activation in a Smad3-dependent manner. In addition, C/EBP? was overexpressed in HTLV-1 infected cell lines and fresh ATL cases. HBZ was able to induce C/EBP? transcription by enhancing its promoter activity. Finally, HBZ selectively modulated the expression of C/EBP? target genes, leading to the impairment of C/EBP?-mediated cell growth suppression. CONCLUSION: HBZ, by suppressing C/EBP? signaling, supports the proliferation of HTLV-1 infected cells, which is thought to be critical for oncogenesis.
AU  - Zhao, T
AU  - Coutts, A
AU  - Xu, L
AU  - Yu, J
AU  - Ohshima, K
AU  - Matsuoka, M
DA  - 2013/12/21
DO  - 10.1186/1742-4690-10-159
EP  - 13
JO  - Retrovirology
PB  - BioMed Central
PY  - 2013/12/21
SP  - 1
TI  - HTLV-1 bZIP factor supports proliferation of adult T cell leukemia cells through suppression of C/EBP? signaling.
VL  - 10
Y1  - 2013/12/21
Y2  - 2026/05/01
ER  -