Methotrexate-based PROTACs as DHFR-specific chemical probes

Author:

Rana, Sandeep

Dranchak, Patricia

Dahlin, Jayme L

Lamy, Laurence

Li,Wenqing

Oliphant, Erin

Shrimp, Jonathan H

Rajacharya, Girish H

Tharakan, Ravi

Holland, David O

Whitten, Apryl S

Wilson, Kelli M

Singh, Pankaj K

Durum,Scott

Tao, Dingyin

Rai, Ganesha

Inglese, James
Author Address

Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, MD 20850, USA., Center for Cancer Research, National Cancer Institute, NIH, Frederick, MD, USA., Department of Oncology Science, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA., Department of Oncology Science, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA; OU Health Stephenson Center, University of Oklahoma Health Science Center, Oklahoma City, OK 73104, USA., Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, MD 20850, USA. Electronic address: bantukallug@mail.nih.gov., Division of Preclinical Innovation, National Center for Advancing Translational Sciences, NIH, Rockville, MD 20850, USA; Metabolic Medicine Branch, National Human Genome Research Institute, NIH, Bethesda, MD 20892, USA. Electronic address: jinglese@mail.nih.gov.,

Abstract:

Methotrexate (MTX) is a tight-binding dihydrofolate reductase (DHFR) inhibitor, used as both an antineoplastic and immunosuppressant therapeutic. MTX, like folate undergoes folylpolyglutamate synthetase-mediated gamma-glutamylation, which affects cellular retention and target specificity. Mechanisms of MTX resistance in cancers include a decrease in MTX poly-gamma-glutamylation and an upregulation of DHFR. Here, we report a series of potent MTX-based proteolysis targeting chimeras (PROTACs) to investigate DHFR degradation pharmacology and one-carbon biochemistry. These on-target, cell-active PROTACs show proteasome- and E3 ligase-dependent activity, and selective degradation of DHFR in multiple cancer cell lines. By comparison, treatment with MTX increases cellular DHFR protein expression. Importantly, these PROTACs produced distinct, less-lethal phenotypes compared to MTX. The chemical probe set described here should complement conventional DHFR inhibitors and serve as useful tools for studying one-carbon biochemistry and dissecting complex polypharmacology of MTX and related drugs. Such compounds may also serve as leads for potential autoimmune and antineoplastic therapeutics.

See More

Author Address