Skip Header

You are using a version of browser that may not display all the features of this website. Please consider upgrading your browser.

A key role of the hSNF5/INI1 tumour suppressor in the control of the G1-S transition of the cell cycle.

Versteege I., Medjkane S., Rouillard D., Delattre O.

The hSNF5/INI1 gene encodes a member of the SWI/SNF chromatin remodelling complexes. It was recently identified as a tumour suppressor gene mutated in sporadic and hereditary Malignant Rhabdoid Tumours (MRT). However, the role of hSNF5/INI1 loss-of-function in tumour development is still unknown. Here, we show that the ectopic expression of wild-type hSNF5/INI1, but not that of truncated versions, leads to a cell cycle arrest by inhibiting the entry into S phase of MRT cells. This G1 arrest is associated with down-regulation of a subset of E2F targets including cyclin A, E2F1 and CDC6. This arrest can be reverted by coexpression of cyclin D1, cyclin E or viral E1A, whereas it cannot be counteracted by pRB-binding deficient E1A mutants. Moreover, hSNF5/INI1 is not able to arrest cells lacking a functional pRB. These observations suggest that the hSNF5/INI1-induced G1 arrest is dependent upon the presence of a functional pRB. However, the observation that a constitutively active pRB can efficiently arrest MRT cells indicates that hSNF5/INI1, at the difference of the ATPase subunits of the SWI/SNF complex, is dispensable for pRB function. Altogether, these data show that hSNF5/INI1 is a potent regulator of the entry into S phase, an effect that may account for its tumour suppressor role.

Oncogene 21:6403-6412(2002) [PubMed] [Europe PMC]

UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

We'd like to inform you that we have updated our Privacy Notice to comply with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.

Do not show this banner again