Identification of a Small Molecule Inhibitor of Hyaluronan Synthesis, DDIT, Targeting Breast Cancer Cells.

Breast cancer is a common cancer in women. Breast cancer cells synthesize large amounts of hyaluronan to assist their proliferation, survival, migration and invasion. Accumulation of hyaluronan and overexpression of its receptor CD44 and hyaluronidase TMEM2 in breast tumors correlate with tumor progression and reduced overall survival of patients. Currently, the only known small molecule inhibitor of hyaluronan synthesis is 4-methyl-umbelliferone (4-MU). Due to the importance of hyaluronan for breast cancer progression, our aim was to identify new, potent and chemically distinct inhibitors of its synthesis. Here, we report a new small molecule inhibitor of hyaluronan synthesis, the thymidine analog 5'-Deoxy-5'-(1,3-Diphenyl-2-Imidazolidinyl)-Thymidine (DDIT). This compound is more potent than 4-MU and displays significant anti-tumorigenic properties. Specifically, DDIT inhibits breast cancer cell proliferation, migration, invasion and cancer stem cell self-renewal by suppressing HAS-synthesized hyaluronan. DDIT appears as a promising lead compound for the development of inhibitors of hyaluronan synthesis with potential usefulness in breast cancer treatment.