Molecular mechanisms of TGFbeta signaling

Our aim is to elucidate molecular mechanisms involved in TGFb signaling in breast cancer.

TGFb has both tumor suppressor (inhibits growth and induces apoptosis) and tumor promoting (stimulates invasiveness and metastasis) effects in cancer.

TGFb binds to type I and type II serine/threonine kinase receptors (TbRI and TbRII, respectively), and induces signaling via Smad molecules acting as transcription factors.We will perform a whole genome CRISPR-Cas9 screen to identify modulators of Smad signaling.

We expect to identify genes encoding proteins that affect pro-tumorigenic and tumor suppressive TGFb signaling pathways.

The mechanism of action of identified genes will be determined using cell culture-based assays for TbRI, TbRII and Smad activation, trafficking or stability.

In addition, their effects on cell proliferation, survival, migration, invasion and epithelial-mesenchymal transition, will be determined.In parallel, we will perform a proteomic screen for posttranslational modifications (PTM:s) of Smads involved in TGFb signaling (Smad2, 3, 4 and 7), using mass spectrometry.

Identified candidate PTM:s will be characterized with regard to their effects on Smad activation, nucleocytoplasmic shuttling and stability.Identified pro-tumorigenic and tumor suppressive mechanisms will be further validated using mouse tumor models.Our goal is to make possible the development of clinically useful, selective TGFb antagonists, inhibiting only the protumorigenic signaling pathways.