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posted on 2024-01-17, 14:20 authored by Joseph L. Sottnik, Madeleine T. Shackleford, Sydney K. Robinson, Fabian R. Villagomez, Shaymaa Bahnassy, Steffi Oesterreich, Junxiao Hu, Zeynep Madak-Erdogan, Rebecca B. Riggins, Bradley R. Corr, Linda S. Cook, Lindsey S. Treviño, Benjamin G. Bitler, Matthew J. Sikora WNT4 variant genotype is associated with active WNT4 signaling and metabolic remodeling in ovarian cancer cells. A, Left, Proliferation assessed by dsDNA quantification 6 days post-transfection with siRNA (siNT = non-targeting control pool). Bars represent mean of 6 biological replicates ± SD; *, P < 0.05, siWNT4 versus siNT, t test with Welch correction. WT versus Var model comparison by t test of mean fold changes for siWNT4 versus siNT. Right, WNT4 mRNA by qPCR in parallel samples, 72 hours after siRNA. Mean of biological triplicate, fold change versus siNT. B, Lysates harvested 72 hours posttransfection. MCL1 levels assessed by densitometry and normalized to total S6 loading control (6). Fold change in normalized MCL1 levels in Variant versus WT genotype cell lines compared by Student t test. C, Metabolites dysregulated 72 hours after WNT4 knockdown (n = 44), as for MM134. D, Fold changes in lipid metabolites. Dashed line on y-axis: FDR = 0.2. E, Pathway enrichment (Metaboanalyst) for metabolites shown in C; K = KEGG, S = SMPDB.
Funding
HHS | NIH | National Cancer Institute (NCI)
Cancer League of Colorado (CLC)
CU | Cancer Center, University of Colorado (CU Cancer Center)
Ovarian Cancer Research Alliance (OCRA)
DOD | USA | MEDCOM | Congressionally Directed Medical Research Programs (CDMRP)
American Cancer Society (ACS)
Golfers Against Cancer (GAC)
CU | Anschutz Medical Campus, University of Colorado (CU AMC)
HHS | National Institutes of Health (NIH)
History
ARTICLE ABSTRACT
Wnt ligand WNT4 is critical in female reproductive tissue development, with WNT4 dysregulation linked to related pathologies including breast cancer (invasive lobular carcinoma, ILC) and gynecologic cancers. WNT4 signaling in these contexts is distinct from canonical Wnt signaling yet inadequately understood. We previously identified atypical intracellular activity of WNT4 (independent of Wnt secretion) regulating mitochondrial function, and herein examine intracellular functions of WNT4. We further examine how convergent mechanisms of WNT4 dysregulation impact cancer metabolism. In ILC, WNT4 is co-opted by estrogen receptor α (ER) via genomic binding in WNT4 intron 1, while in gynecologic cancers, a common genetic polymorphism (rs3820282) at this ER binding site alters WNT4 regulation. Using proximity biotinylation (BioID), we show canonical Wnt ligand WNT3A is trafficked for secretion, but WNT4 is localized to the cytosol and mitochondria. We identified DHRS2, mTOR, and STAT1 as putative WNT4 cytosolic/mitochondrial signaling partners. Whole metabolite profiling, and integrated transcriptomic data, support that WNT4 mediates metabolic reprogramming via fatty acid and amino acid metabolism. Furthermore, ovarian cancer cell lines with rs3820282 variant genotype are WNT4 dependent and have active WNT4 metabolic signaling. In protein array analyses of a cohort of 103 human gynecologic tumors enriched for patient diversity, germline rs3820282 genotype is associated with metabolic remodeling. Variant genotype tumors show increased AMPK activation and downstream signaling, with the highest AMPK signaling activity in variant genotype tumors from non-White patients. Taken together, atypical intracellular WNT4 signaling, in part via genetic dysregulation, regulates the distinct metabolic phenotypes of ILC and gynecologic cancers.
WNT4 regulates breast and gynecologic cancer metabolism via a previously unappreciated intracellular signaling mechanism at the mitochondria, with WNT4 mediating metabolic remodeling. Understanding WNT4 dysregulation by estrogen and genetic polymorphism offers new opportunities for defining tumor biology, precision therapeutics, and personalized cancer risk assessment.
