Targeting the MAtrix REgulating MOtif, MAREMO, abolishes hallmarks of cancer

Tumor targeted therapies have been largely inefficient due to lack of concomitant effects on the tumor microenvironment (TME). We investigated the MAtrix REgulating MOtif (MAREMO) mimicking peptide MP5, that inhibits the pro-tumorigenic extracellular matrix (ECM) molecule tenascin-C, using immunocompetent autologous breast cancer bearing mice. MP5 treatment led to tumor regression and reduced tumor cell dissemination. Several cancer hallmarks were abolished such as tumor cell promoting growth suppression and inhibition of plasticity enhancing responsiveness to death inducers. MP5 acts on other TME players leading to blood vessel normalization and depletion of fibroblasts diminishing the ECM as an orchestrator of immune suppression, causing immune cell infiltration and reactivation of anti-tumor immunity involving IFNgamma. Thus, targeting the tumor matrix using MAREMO in tenascin-C represents a powerful novel anti-cancer strategy.