Context-dependent therapeutic targeting of ovarian cancer metastasis using TG2 small molecule inhibitors

Ovarian cancer (OC) is the leading cause of death among gynecological malignancies. Due to the insidious symptoms, it is diagnosed in late stages when the cancer cells have already disseminated. A major issue in the management of this disease is that OC tumors develops resistance to drugs used in front line treatment. Over the past decade, several studies have reported tissue transglutaminase (TG2) overexpression in cancer. Specifically, in OC, TG2 has been shown to promote all stages of tumor progression. TG2 was found to be highly expressed in ovarian cancer stem cells and linked to chemotherapy resistance. Our recent data suggest decreased tumor burden concurrently with increased infiltration, activation and effector functions of T cells, and loss of immunosuppressive signals in the tumor microenvironment resulting in development of an anti-tumorigenic phenotype in TG2 knock-out mice. The physiological roles of TG2 are regulated by cellular context and localization. At the plasma membrane, TG2 binds to the gelatin-binding domain of fibronectin (FN) with high affinity and this complex provides a binding site for beta 1 and beta 3 integrins thus increasing cells capacity to attach and migrate onto the metastatic niche. In this project we aim at developing new inhibitors targeting the TG2-FN interaction. We propose new drug development activities for testing second generation compounds with improved pharmacokinetics features and to assess TG2 inhibitors’ potential to be used as anti-metastatic drugs in combination with other chemo- and immune-therapeutic agents.