Dual Covalent Inhibition of PKM and IMPDH Targets Metabolism in Cutaneous Metastatic Melanoma

Area of Science:

• Oncology
• Metabolic pathways
• Drug resistance

Background:

• Acquired drug resistance is a major hurdle in cancer treatment, particularly in BRAF^V600E cutaneous metastatic melanoma (CMM), where over 50% of patients develop resistance to BRAF inhibitors.
• Metabolic reprogramming in resistant cancer cells significantly impacts treatment outcomes and tumor progression.

Purpose of the Study:

• To identify novel therapeutic strategies targeting metabolic vulnerabilities in CMM to overcome drug resistance.
• To investigate the efficacy of a novel dual-action drug, HA344, against vemurafenib-resistant CMM.

Main Methods:

• Identification of HA344, a covalent inhibitor targeting pyruvate kinase M2 (PKM2) in glycolysis and inosine monophosphate dehydrogenase in de novo guanylate synthesis.
• Assessment of HA344's effect on vemurafenib-sensitive and resistant CMM cell lines in vitro and on CMM xenograft tumor growth in mice.
• Evaluation of synergistic effects between HA344 and BRAF inhibitors.

Main Results:

• HA344 effectively inhibited both glycolysis and guanylate synthesis pathways by targeting PKM2 and inosine monophosphate dehydrogenase, respectively.
• HA344 demonstrated efficacy against both vemurafenib-sensitive and resistant CMM cells in vitro.
• HA344 treatment led to impaired CMM xenograft tumor growth in mice and showed synergistic effects with BRAF inhibitors.

Conclusions:

• HA344's dual targeting of critical metabolic hubs offers a promising therapeutic approach for CMM, including drug-resistant cases.
• The mechanism of action of HA344 suggests potential applications beyond CMM, addressing resistance in a broad spectrum of cancers by targeting deregulated glycolytic and purine synthesis pathways.