Biology subjects

Zolkind, P.

Publications and source records attributed to Zolkind, P..

4 recordsLinked to original sources

bioRxiv2025

Pyrimethamine and a potent analogue WCDD115 inhibit NRF2 by suppressing DHFR and one-carbon metabolism

Nuclear factor erythroid 2-related factor 2 (NFE2L2/NRF2) is a critical mediator of the cellular oxidative stress response. Aberrant activation of NRF2 is common in lung and upper aerodigestive cancers, where it promotes tumor initiation and progression and confers resistance to chemotherapy, radiation therapy, and immune checkpoint inhibitors. As such, NRF2 therapeutic inhibitors are actively being sought. We previously reported that the antiparasitic drug Pyrimethamine (PYR) inhibits NRF2 in cell lines and in a NRF2-inducible genetically engineered mouse model. Here we design, synthesize, and define structure-activity relationships across a series of 25 PYR-based derivatives to reveal WCDD115 as a 22-fold more potent inhibitor of NRF2 (57nM versus 1.2{micro}M). PYR is known to inhibit plasmodial and human dihydrofolate reductase (DHFR). We found that WCDD115 inhibits hDHFR with 31-fold greater potency than PYR (144nM versus 4.49{micro}M). Metabolomics showed strong similarities between PYR, WCDD115 and methotrexate. Genetic, pharmacological and metabolic epistasis studies reveal that DHFR inactivation is required for NRF2 suppression by WCDD115 and PYR. Global and targeted proteomics revealed overlapping profiles for WCDD115, PYR and methotrexate, including suppression of NRF2 oxidative stress response and activation of TP53 and the DNA damage response. Therefore, PYR and a novel potent derivative WCDD115 are effective, indirect inhibitors of NRF2 and its antioxidant functions. These data underscore the importance of one- carbon metabolism for the NRF2 signaling pathway and support a new therapeutic strategy to suppress NRF2-driven cancer biology.

cancer biology↗

bioRxiv2024

Suppression of NRF2-dependent cancer growth by a covalent allosteric molecular glue

The NRF2 transcription factor is constitutively active in cancer where it functions to maintain oxidative homeostasis and reprogram cellular metabolism. NRF2-active tumors exhibit NRF2-dependency and resistance to chemo/radiotherapy. Here we characterize VVD-065, a first-in-class NRF2 inhibitor that acts via an unprecedented allosteric molecular glue mechanism. In the absence of stress or mutation, NRF2 is rapidly degraded by the KEAP1-CUL3 ubiquitin-ligase complex. VVD-065 specifically and covalently engages C151 on KEAP1, which in turn promotes KEAP1-CUL3 complex formation, leading to enhancement of NRF2 degradation. Previously reported C151-directed compounds decrease KEAP1-CUL3 interactions and stabilize NRF2, thus establishing KEAP1_C151 as a tunable regulator of the KEAP1-CUL3 complex and NRF2 stability. VVD-065 inhibited NRF2-dependent tumor growth and sensitized cancers to chemo/radiotherapy, supporting an open Phase I clinical trial (NCT05954312).

cancer biology↗

bioRxiv2023

Targeted proteomic quantitation of NRF2 signaling and predictive biomarkers in HNSCC

The NFE2L2/NRF2 oncogene and transcription factor drives a gene expression program that promotes cancer progression, metabolic reprogramming, immune evasion and chemoradiation resistance. Patient stratification by NRF2 activity may guide treatment decisions to improve outcome. Here, we developed a mass spectrometry (MS)-based targeted proteomics assay based on internal standard triggered parallel reaction monitoring (IS-PRM) to quantify 69 NRF2 pathway components and targets as well as 21 proteins of broad clinical significance in head and neck squamous cell carcinoma (HNSCC). We improved the existing IS-PRM acquisition algorithm, called SureQuant, to increase throughput, sensitivity, and precision. Testing the optimized platform on 27 lung and upper aerodigestive cancer cell models revealed 35 NRF2 responsive proteins. In formalin-fixed paraffin-embedded (FFPE) HNSCCs, NRF2 signaling intensity positively correlated with NRF2 activating mutations and with SOX2 protein expression. PD-L2/CD273 and protein markers of T-cell infiltration correlated positively with one another and with human papilloma virus (HPV) infection status. p16/CDKN2A protein expression positively correlated with the HPV oncogenic E7 protein, and confirmed the presence of translationally active virus. This work establishes a clinically actionable HNSCC protein biomarker assay capable of quantifying over 600 peptides from frozen or FFPE archived tissues in under 90 minutes.

cancer biology↗

bioRxiv2021

Comparative Multiomic Analysis Reveals Low T Cell Infiltration as the Primary Feature of Tobacco Use in HPV(+) Oropharyngeal Cancer

PurposeTobacco use is an independent adverse prognostic feature in human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (OPSCC). Despite this, the biologic features associated with tobacco use have not been systematically investigated in this population. We sought to characterize the genomic and immunologic features of HPV(+) OPSCC associated with tobacco use and adverse oncologic outcomes. Experimental DesignWhole exome sequencing of 47 primary HPV(+) OPSCC tumors was performed to investigate mutational differences associated with tobacco exposure. To characterize the tumor immune microenvironment (TIME), targeted mRNA hybridization was performed and immunohistochemical (IHC) staining was used to validate these findings. ResultsLow expression of transcripts in a T cell-inflamed gene expression profile (TGEP) was associated with tobacco use at the time of diagnosis and lower overall and disease-free survival. Tobacco use was associated with an increased proportion of T>C substitutions and a lower proportion of mutational signatures typically observed in HPV(+) OPSCC tumors, but was not associated with increases in mutational burden or the rate of recurrent oncogenic mutations. ConclusionsIn HPV(+) OPSCC, low T cell infiltration of primary tumors is associated with current tobacco use and worse oncologic outcomes. Rather than an increased mutational burden, tobaccos primary and clinically relevant association is immunosuppression of the primary TIME. An objective clinical assay like the TGEP, which quantifies immune infiltration of the primary TIME, may have value for HPV(+) OPSCC risk stratification in future clinical trials.

cancer biology↗