Zinc-finger protein 768 (ZNF768) is an emerging transcription factor regulating cell proliferation and senescence. Although the role of ZNF768 in regulating cell fate decision has been demonstrated in Show more
Zinc-finger protein 768 (ZNF768) is an emerging transcription factor regulating cell proliferation and senescence. Although the role of ZNF768 in regulating cell fate decision has been demonstrated in vitro, its importance in controlling physiological and pathophysiological processes in vivo is still unclear. Here, we report the generation of a transgenic mouse model allowing the conditional overexpression of ZNF768. This was achieved by inserting an inverted Znf768 coding sequence surrounded by heterologous Cre recognition sites in the Gt(ROSA)26Sor mouse locus (FLExZnf768). To study the impact linked to systemic overexpression of ZNF768, mice carrying the FLExZnf768 allele were crossed with CMV-Cre mice to produce a whole-body ZNF768 transgenic mouse (WB-ZNF768-Tg). As expected, WB-ZNF768-Tg mice showed higher ZNF768 levels in various tissues. These mice were born at the expected Mendelian ratio and did not display apparent phenotypes. Because ZNF768 levels are often overexpressed in cancer, we assessed tumor development in WB-ZNF768-Tg mice. However, ZNF768 overexpression was not sufficient to promote 3-methylcholantrene-induced fibrosarcoma and KRAS Show less
RAS proteins are GTPases that lie upstream of a signaling network impacting cell fate determination. How cells integrate RAS activity to balance proliferation and cellular senescence is still incomple Show more
RAS proteins are GTPases that lie upstream of a signaling network impacting cell fate determination. How cells integrate RAS activity to balance proliferation and cellular senescence is still incompletely characterized. Here, we identify ZNF768 as a phosphoprotein destabilized upon RAS activation. We report that ZNF768 depletion impairs proliferation and induces senescence by modulating the expression of key cell cycle effectors and established p53 targets. ZNF768 levels decrease in response to replicative-, stress- and oncogene-induced senescence. Interestingly, ZNF768 overexpression contributes to bypass RAS-induced senescence by repressing the p53 pathway. Furthermore, we show that ZNF768 interacts with and represses p53 phosphorylation and activity. Cancer genomics and immunohistochemical analyses reveal that ZNF768 is often amplified and/or overexpressed in tumors, suggesting that cells could use ZNF768 to bypass senescence, sustain proliferation and promote malignant transformation. Thus, we identify ZNF768 as a protein linking oncogenic signaling to the control of cell fate decision and proliferation. Show less