A critical role for Mnt in Myc-driven T-cell proliferation and oncogenesis.
نویسندگان
چکیده
Mnt (Max's next tango) is a Max-interacting transcriptional repressor that can antagonize both the proproliferative and proapoptotic functions of Myc in vitro. To ascertain the physiologically relevant functions of Mnt and to help define the relationship between Mnt and Myc in vivo, we generated a series of mouse strains in which Mnt was deleted in T cells in the absence of endogenous c-Myc or in the presence of ectopic c-Myc. We found that apoptosis caused by loss of Mnt did not require Myc but that ectopic Myc expression dramatically decreased the survival of both Mnt-deficient T cells in vivo and Mnt-deficient MEFs in vitro. Consequently, Myc-driven proliferative expansion of T cells in vitro and thymoma formation in vivo were prevented by the absence of Mnt. Consistent with T-cell models, mouse embryo fibroblasts (MEFs) lacking Mnt were refractory to oncogenic transformation by Myc. Tumor suppression caused by loss of Mnt was linked to increased apoptosis mediated by reactive oxygen species (ROS). Thus, although theoretically and experimentally a Myc antagonist, the dominant physiological role of Mnt appears to be suppression of apoptosis. Our results redefine the physiological relationship between Mnt and Myc and requirements for Myc-driven oncogenesis.
منابع مشابه
MYC needs MNT
MYC family members c-MYC, N-MYC and L-MYC are amplified, translocated and otherwise deregulated in numerous and diverse tumor types. These events, which typically lead to constitutively increased MYC, provide a proliferative advantage to cells by boosting anabolic metabolism and supporting cell cycle progression. However, the proliferative response to excessive MYC is countered in many cell typ...
متن کاملMNT and Emerging Concepts of MNT-MYC Antagonism
MYC family proteins play fundamental roles in stem and progenitor cell homeostasis, morphogenesis and cancer. As expected for proteins that profoundly affect the fate of cells, the activities of MYC are regulated at a multitude of levels. One mechanism with the potential to broadly affect the activities of MYC is transcriptional antagonism by a group of MYC-related transcriptional repressors. F...
متن کاملThe transcriptional repressor dMnt is a regulator of growth in Drosophila melanogaster.
The Myc-Max-Mad/Mnt network of transcription factors has been implicated in oncogenesis and the regulation of proliferation in vertebrate cells. The identification of Myc and Max homologs in Drosophila melanogaster has demonstrated a critical role for dMyc in cell growth control. In this report, we identify and characterize the third member of this network, dMnt, the sole fly homolog of the mam...
متن کاملMnt–Max to Myc–Max complex switching regulates cell cycle entry
The c-Myc oncoprotein is strongly induced during the G0 to S-phase transition and is an important regulator of cell cycle entry. In contrast to c-Myc, the putative Myc antagonist Mnt is maintained at a constant level during cell cycle entry. Mnt and Myc require interaction with Max for specific DNA binding at E-box sites, but have opposing transcriptional activities. Here, we show that c-Myc in...
متن کاملEffect of valproic acid on JAK/STAT pathway, SOCS1, SOCS3, Bcl-xL, c-Myc, and Mcl-1 gene expression, cell growth inhibition and apoptosis induction in human colon cancer HT29 cell line.
Background and aim: Cytokines are a large family of protein messengers. These proteins induce various cellular responses. Janus kinases (JAKs) are mediators of cytokine, activated JAKs phosphorylate signal transducers, and activators of transcription (STAT) proteins that regulate cell differentiation, proliferation, and apoptosis. Aberrant JAK/STAT signaling is involved in the oncogenesis of se...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 109 48 شماره
صفحات -
تاریخ انتشار 2012