Abstract: The present invention relates to a method for preventing or treating a cancer disease by targeting the epigenetic factor Chromodomain on Y-like 2 (CDYL2). The inventors found that CDYL2 is commonly over-expressed in cancer and high CDYL2 levels correlate with poor prognosis in a number of cancer types even in drug resistant cancer. CDYL2 upregulation in a breast cancer cell line induced migration, invasion, stem-like phenotypes, as well as an epithelial-to-mesenchymal transition (EMT). Due to the importance of EMT and stemness in therapeutic resistance and relapse in cancer, the inventors propose that CDYL2 inhibition will also be beneficial to the treatment of such cancers. Furthermore RNAi inhibition of CDYL2 diminished these same EMT-associated processes in the mesenchymal-like breast cancer cell line.

Abstract: A method of prognosis of patient outcome and of the resistance to a chemotherapy treatment of an individual afflicted by a tumor. The method involves determining the amount of the product of each of at least 21 genes belonging to the group of 160 genes as set forth in SEQ ID NO: 1 to SEQ ID NO: 160.