Mechanism of PTEN loss mediated cancer development

Mechanism of PTEN loss mediated cancer development

The tumor suppressor PTEN, which antagonizes PI3K signalling, is frequently inactivated in haematologic malignancies. The authors in the journal Nature Communications unravel the main contribution of the PI3K isoform p110ß to leukemic transformation driven by PTEN-loss.

In mice, deletion of PTEN in haematopoietic stem cells (HSCs) causes perturbed haematopoiesis, myeloproliferative neoplasia (MPN) and leukaemia.

Although the roles of the PI3K isoforms have been studied in PTEN-deficient tumours, their individual roles in PTEN-deficient HSCs are unknown.

The authors show that when they delete PTEN in HSCs, p110β ablation prevents MPN, improves HSC function and suppresses leukaemia initiation. Pharmacologic inhibition of p110β in PTEN-deficient mice recapitulates these genetic findings, but suggests involvement of both Akt-dependent and -independent pathways.

Further investigation reveals that a p110β–Rac signalling loop plays a critical role in PTEN-deficient HSCs. Together, these data suggest that myeloid neoplasia driven by PTEN loss is dependent on p110β via p110β–Rac-positive-feedback loop, and that disruption of this loop may offer a new and effective therapeutic strategy for PTEN-deficient leukaemia.
http://www.nature.com/ncomms/2015/151007/ncomms9501/full/ncomms9501.html
Edited

Rating

Unrated
Rating: