Small-molecule inhibitors shown to promote robust antitumor immunity

Purdue University researchers have developed a new series of small-molecule inhibitors that enhance antitumor immunity and could serve as anticancer agents. The lead researcher, Zhong-Yin Zhang, pioneered L-32, a quinolone-based inhibitor, which has shown potential in reducing tumor growth and boosting the effectiveness of previous derivatives.

PTPN22, a protein tyrosine phosphatase, plays a crucial role in immune regulation, and mutations in this protein serve as risk factors for multiple autoimmune disorders. By inhibiting PTPN22 with small-molecule inhibitors, Zhang aims to stimulate both innate and adaptive immunity against tumor cells.

Despite PTPN22's known roles in cancer immunity, it has been underexplored as a therapeutic target due to the lack of high-quality small-molecule inhibitors. Zhang's team addressed this gap by creating a novel strategy to develop potent and selective PTP inhibitors, targeting both the active site and nearby unique pockets of the protein.

They identified L-32 from a collection of druglike small molecules and demonstrated its improved potency, selectivity, and cellular efficacy compared to earlier compounds. L-32 also boasts a more favorable pharmacokinetic profile and drug properties, including oral bioavailability.

In syngeneic MC38 tumor models, L-32 has proven superior to previous molecules in reducing tumor growth by promoting robust antitumor immunity, making it a promising lead molecule for novel anticancer agents targeting PTPN22. The next steps for Zhang's research involve optimizing L-32 and evaluating its efficacy in more challenging cancers, such as pancreatic and liver cancers, as well as those resistant to current immunotherapies.