Targeting c-MYC and gain-of-function p53 through inhibition or degradation of the kinase LZK suppresses the growth of HNSCC tumors.

Abstract

The worldwide annual frequency and lethality of head and neck squamous cell carcinoma (HNSCC) is not improving, and thus, new therapeutic approaches are needed. Approximately 70% of HNSCC cases have either amplification or overexpression of MAP3K13, which encodes the kinase LZK. Here, we found that LZK is a therapeutic target in HNSCC and that small-molecule inhibition of its catalytic function decreased the viability of HNSCC cells with amplified MAP3K13. Inhibition of LZK suppressed tumor growth in MAP3K13-amplified xenografts derived from HNSCC patients. LZK stabilized the transcription factor c-MYC through its kinase activity and gain-of-function mutants of p53 in a kinase-independent manner. We designed a proteolysis-targeting chimera (PROTAC) that induced LZK degradation, leading to decreased abundance of both c-MYC and gain-of-function p53, and reduced the viability of HNSCC cells. Our findings demonstrate that LZK-targeted therapeutics, particularly PROTACs, may be effective in treating HNSCCs with MAP3K13 amplification.