Combined therapeutic targeting of the KLK/MMP9 axis as a novel therapy for metastatic cancer

Growing evidence suggests that kallikrein-related protease 6 (KLK6) is a key factor driving the invasion and migration of some primary tumors. This increase of tumor cell migration and invasion has been linked to the activation of KLK6 by matrix metalloproteinase-9 (MMP-9), making both proteins potential targets for therapeutic intervention. Dual-specific agents that can inhibit the activities of both targets have enhanced potential compared to single-targeted agents due to the differential expression of these disease markers in different tissues and patients, and the ability of this expression to change over time.
In this research we are developing a new class of dual-specific KLK6/MMP9 inhibitors. The inhibitors combine the N-terminal domain of tissue inhibitors of metalloproteinase-2 (N-TIMP2) and a synthetic small molecule (DKFZ 938) specifically engineered to inhibit KLK6. Our strategy was based on incorporating a noncanonical amino acid (NCAA) into N-TIMP2 to enable site specific conjugation to the small molecule. For that, we incorporated the NCAA propargyl lysine (PrK) at position S31 of N-TIMP2, which does not interfere with the N-TIMP2-MMP-9 binding interface. Next, we performed a click reaction between N-TIMP2-S31PrK and DKFZ 938 to generate the N-TIMP2-DKFZ 938 conjugate, which demonstrated a potent inhibitory function against both KLK6 and MMP9. We now plan to test the inhibitory activity of the conjugate in cell and in vivo and develop it as anti-cancer therapeutic.