P16^Ink4a and p21^Cip1/Waf1 promote tumour growth by enhancing myeloid-derived suppressor cells chemotaxis.

ABSTRACT: p16^Ink4a and p21^Cip1/Waf1 act as tumour suppressors through induction of cellular senescence. However, senescence-independent roles of these CDK inhibitors are not well understood. Here, we report an unexpected function of p16^Ink4 and p21^Cip1/Waf1, namely, tumour promotion through chemotaxis. In monocytic myeloid-derived suppressor cells (Mo-MDSCs), p16^Ink4 and p21^Cip1/Waf1 are highly expressed and stimulate CX3CR1 chemokine receptor expression by preventing CDK-mediated phosphorylation and inactivation of SMAD3. Thus, deletion of p16 ^Ink4 and p21 ^Cip1/Waf1 reduces CX3CR1 expression, thereby inhibiting Mo-MDSC accumulation in tumours expressing CX3CL1 and suppressing the tumour progression in mice. Nota

SUBMITTER: Okuma A 

PROVIDER: S-EPMC5727112 | biostudies-literature | 2017 Dec

REPOSITORIES: biostudies-literature