CRL4DCAF4 E3 ligase-mediated degradation of MEN1 transcriptionally reactivates hTERT to sustain immortalization in colorectal cancer cells

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Telomerase reactivation is implicated in approximately 85% of human cancers, yet its underlying mechanism remains elusive. In this study, we elucidate that the Cullin RING Ubiquitin Ligase 4 (CRL4) complex drives the reactivation of human telomerase reverse transcriptase (hTERT) in colorectal cancer (CRC) by degrading the tumor suppressor, menin 1 (MEN1). Our data show that, in noncancerous intestinal epithelial cells, the transcription factor specificity protein 1 (Sp1) recruits both the histone acetyltransferase p300 and MEN1 to suppress hTERT expression, thus maintaining telomere shortness post-cell division. Inflammation-induced microenvironments trigger an activation of the CRL4DCAF4 E3 ligase, leading to MEN1 ubiquitination and degradation in CRC cells. This process nullifies MEN1's inhibitory action, reactivates hTERT expression at the transcriptional level, interrupts telomere shortening, and spurs uncontrolled cellular proliferation. Notably, MEN1 overexpression in CRC cells partially counteracts these oncogenic phenotypes. NSC1517, an inhibitor of the CRL4DCAF4 complex identified through high-throughput screening from a plant-derived chemical pool, hinders MEN1 degradation, attenuates hTERT expression, and suppresses tumor growth in mouse xenograft models. Collectively, our research elucidates the transcriptional mechanism driving hTERT reactivation in CRC. Targeting the CRL4DCAF4 E3 ligase emerges as a promising strategy to counteract cancer cell immortalization and curb tumor progression.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - year:2024

Enthalten in:

Carcinogenesis - (2024) vom: 04. Apr.

Sprache:

Englisch

Beteiligte Personen:

Ao, Zhimin [VerfasserIn]
Xiao, Dan [VerfasserIn]
Wu, Jing [VerfasserIn]
Sun, Ji [VerfasserIn]
Liu, Hong [VerfasserIn]

Links:

Volltext

Themen:

CRL4DCAF4 E3 ligase
Colorectal cancer
HTERT
Journal Article
MEN1
NSC1517

Anmerkungen:

Date Revised 04.04.2024

published: Print-Electronic

Citation Status Publisher

doi:

10.1093/carcin/bgae024

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM370627490