Canonical Wnt is inhibited by targeting one-carbon metabolism through methotrexate or methionine deprivation

Abstract

The nutrient-sensing metabolite S-adenosylmethionine (SAM) controls one-carbon metabolism by donating methyl groups to biochemical building blocks, DNA, RNA, and protein. Our recent work uncovered a requirement for cytoplasmic arginine methylation during Wnt signaling through the activity of protein arginine methyltransferase 1 (PRMT1), which transfers one-carbon groups from SAM to many protein substrates. Here, we report that treatments that decrease levels of the universal methyl donor SAM were potent inhibitors of Wnt signaling and of Wnt-induced digestion of extracellular proteins in endolysosomes. Thus, arginine methylation provides the canonical Wnt pathway with metabolic sensing properties through SAM. The rapid accumulation of Wnt-induced endolysosomes within 30 minutes was inhibited by the depletion of methionine, an essential amino acid that serves as the direct substrate for SAM production. We also found that methionine is required for GSK3 sequestration into multivesicular bodies through microautophagy, an essential step in Wnt signaling activity. Methionine starvation greatly reduced Wnt-induced endolysosomal degradation of extracellular serum proteins. Similar results were observed by addition of nicotinamide (vitamin B3), which serves as a methyl group sink. Methotrexate, a pillar in the treatment of cancer since 1948, decreases SAM levels. We show here that methotrexate blocked Wnt-induced endocytic lysosomal activity and reduced canonical Wnt signaling. Importantly, the addition of SAM during methionine depletion or methotrexate treatment was sufficient to rescue endolysosomal function and Wnt signaling. Inhibiting the Wnt signaling pathway by decreasing one-carbon metabolism provides a platform for designing interventions in Wnt-driven disease.

Methionine improves feather follicle development in chick embryos by activating Wnt/β-catenin signaling

“…Several signaling molecules have been found to participate in the formation and development of follicles, and these include Wnt/β-catenin, Sonic Hedgehog, bone morphogenetic proteins, and Notch ( Harris et al., 2010 ; Ouji et al., 2013 ; Ouspenskaia et al., 2016 ; Cheng et al., 2018 ). Albrecht et al. (2019) proved that Met deficiency causes a decrease in Wnt/β-catenin activity in vitro.…”

“…Current studies on the effects of L- or DL-Met on the development of feather follicles are limited to descriptions of characteristics and molecular mechanisms have rarely been reported. Albrecht et al. (2019) revealed that L-Met deletion disrupts Wnt/β-catenin signaling in HeLa cells, and this disruption can be rescued by S-adenosylmethionine ( SAM , a direct metabolite of Met) supplementation during Met depletion.…”

The complexity of the serine glycine one-carbon pathway in cancer

“…2). Conversely, methotrexate could be used to treat Wnt-driven malignancies by suppressing SAM levels and blocking arginine methylation (Albrecht et al, 2019). Similarly, inhibiting the synthesis or utilization of SAM could curtail acquired resistance by preventing transdifferentiation mechanisms and by effectively removing TICs that might cause cancer recurrence (Reina-Campos et al, 2019;Visvader and Lindeman, 2008;Wang et al, 2019).…”

S-adenosylhomocysteine hydrolase regulates anterior patterning inDugesia japonica

“…It is known that Notum is regulated by β-catenin and change in spatial expression of Notum suggests potential changes in β-catenin activity [35]. Given the recently shown importance of methylation and one-carbon metabolism in canonical Wnt signaling by De Robertis group, we speculate that disruption of the methionine cycle may lead to failure in planarian body plan maintenance via changes in Wnt signaling [36], [37]. Although we did not find β-catenin target genes among differentially expressed genes in AdOx-adapted worms, it does not exclude possible changes in post-translational regulation.…”