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Heaton, A. R.

Publications and source records attributed to Heaton, A. R..

2 recordsLinked to original sources

Atovaquone-induced therapeutic rewiring of melanoma metabolism

Melanoma continues to be the deadliest form of skin cancer, emphasizing the need for new therapeutic strategies. Targeting tumor metabolism, particularly oxidative phosphorylation (OXPHOS) has emerged as a promising approach due its role in melanoma tumor survival, metastasis, and treatment resistance. In this study, we investigate the metabolic and antitumor effects of atovaquone, an FDA-approved and safe OXPHOS inhibitor that has not been previously tested in melanoma. We show that atovaquone rapidly and effectively inhibits OXPHOS and impairs glycolysis in melanoma, leading to metabolic reprogramming observed via metabolic imaging and marked depletion in energy (ATP) stores. Atovaquone also induces oxidative stress, evidenced by increased reactive oxygen species levels, DNA damage, and upregulation of antioxidant proteins. Moreover, atovaquone reduced melanoma cell viability and migration in vitro, and slowed tumor growth in vivo. Notably, these effects were observed in both BRAF-wild-type and mutant melanoma models, suggesting its potential as an effective treatment across different subtypes. Our study identifies atovaquone as a metabolic disruptor with antitumor activity against melanoma, supporting further investigation as a repurposed therapeutic strategy.

cancer biology↗

Quantifying in vivo collagen reorganization during immunotherapy in murine melanoma with second harmonic generation imaging

SignificanceIncreased collagen linearization and deposition during tumorigenesis can impede immune cell infiltration and lead to tumor metastasis. Although melanoma is well studied in immunotherapy research, studies that quantify collagen changes during melanoma progression and treatment are lacking. AimImage in vivo collagen in preclinical melanoma models during immunotherapy and quantify the collagen phenotype in treated and control mice. ApproachSecond harmonic generation imaging of collagen was performed in mouse melanoma tumors in vivo over a treatment time-course. Animals were treated with a curative radiation and immunotherapy combination. Collagen morphology was quantified over time at an image and single fiber level using CurveAlign and CT-FIRE software. ResultsIn immunotherapy-treated mice, collagen reorganized toward a healthy phenotype, including shorter, wider, curlier collagen fibers, with modestly higher collagen density. Temporally, collagen fiber straightness and length changed late in treatment (Day 9 and 12) while width and density changed early (Day 6) compared to control mice. Single fiber level collagen analysis was most sensitive to the changes between treatment groups compared to image level analysis. ConclusionsQuantitative second harmonic generation imaging can provide insight into collagen dynamics in vivo during immunotherapy, with key implications in improving immunotherapy response in melanoma and other cancers.

cancer biology↗