14-3-3ζ targeting induced senescence in Hep-2 laryngeal cancer cell through deneddylation of Cullin1 in the Skp1-Cullin-F-box protein complex.
Cell Prolif
; 52(5): e12654, 2019 Sep.
Article
in En
| MEDLINE
| ID: mdl-31222857
ABSTRACT
OBJECTIVES:
Despite of the aberrant expression of 14-3-3ζ in head and neck squamous cell carcinoma (HNSCC), little is known about the role of 14-3-3ζ in the regulation of senescence in HNSCC. This study was performed to investigate whether 14-3-3ζ is implicated in senescence evasion of Hep-2 laryngeal cancer cells.METHODS:
The expression of 14-3-3ζ was suppressed using RNA interference strategy. Senescence induction was determined by senescence-associated ß-galactosidase staining and the numbers of promyelocytic leukaemia nuclear body. Real-time PCR, western blotting and immunohistochemistry were applied for the expression of corresponding proteins. Xenograft experiment was performed to show in vivo effect of 14-3-3ζ silencing on tumour growth.RESULTS:
14-3-3ζ silencing significantly induced senescence phenotypes via 27 accumulations. Subsequently, we demonstrated that p27 accumulation is linked to inactivation of SCFSkp2 complex activity, probably due to the deneddylation of cullin-1 (Cul-1) as follows. (a) Neddylated Cul-1 is decreased by 14-3-3ζ silencing. (b) Blocking neddylation using MLN4924 reproduces senescence phenotypes. (c) Knockdown of CSN5, which functions as a deneddylase, was shown to restore the senescence phenotypes induced by 14-3-3ζ depletion. Finally, we demonstrated that 14-3-3ζ depletion effectively hindered the proliferation of Hep-2 cells implanted into nude mice.CONCLUSION:
14-3-3ζ negatively regulates senescence in Hep-2 cells, suggesting that 14-3-3ζ targeting may serve to suppress the expansion of laryngeal cancer via induction of senescence through the Cul-1/SCFSkp2 /p27 axis.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Cullin Proteins
/
F-Box Proteins
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S-Phase Kinase-Associated Proteins
/
14-3-3 Proteins
Limits:
Animals
/
Humans
/
Male
Language:
En
Year:
2019
Type:
Article