A novel p70 S6 kinase-microRNA biogenesis axis mediates multicellular spheroid formation in ovarian cancer progression.

ABSTRACT: Ovarian cancer is the leading cause of death of all gynecologic tumors, associated with widespread peritoneal dissemination and malignant ascites. Key to this is the ability to form multicellular spheroids (MCS); however, the tumor-specific factors that regulate MCS formation are unclear. p70 S6 kinase (p70S6K), which is a downstream effector of phosphatidylinositol 3-kinase/Akt, is frequently constitutively active in ovarian carcinoma. Here we identify p70S6K as a vital regulator of MCS formation. We also uncover a new mechanism of p70S6K function as a component of the microRNA biogenesis machinery in this process. We show that p70S6K phosphorylates, and inhibits the interaction of tristetraprolin (TTP) and Dicer that promotes the expression of a subset of miRNAs, including the maturation

SUBMITTER: Lam SS 

PROVIDER: S-EPMC5122372 | biostudies-literature | 2016 Jun

REPOSITORIES: biostudies-literature