Pilot study demonstrating metabolic and anti-proliferative effects of in vivo anti-oxidant supplementation with N-Acetylcysteine in Breast Cancer

Publication date: Available online 10 October 2017
Source:Seminars in Oncology
Author(s): Daniel Monti, Federica Sotgia, Diana Whitaker Menezes, Madalina Tuluc, Ruth Birbe, Adam Berger, Melissa Lazar, Paolo Cotzia, Rossitza Draganova-Tacheva, Zhao Lin, Marina Domingo-Vidal, Andrew Newberg, Michael P. Lisanti, Ubaldo Martinez-Outschoorn
BackgroundHigh oxidative stress as defined by hydroxyl and peroxyl activity is often found in the stroma of human breast cancers. Oxidative stress induces stromal catabolism, which promotes cancer aggressiveness. Stromal cells exposed to oxidative stress release catabolites such as lactate, which are up-taken by cancer cells to support mitochondrial oxidative phosphorylation. The transfer of catabolites between stromal and cancer cells leads to metabolic heterogeneity between these cells and increased cancer cell proliferation and reduced apoptosis in preclinical models. N-Acetylcysteine (NAC) is an antioxidant, which reduces oxidative stress, reverses stromal catabolism, and stromal-carcinoma cell metabolic heterogeneity resulting in reduced proliferation and increased apoptosis of cancer cells in experimental models of breast cancer. The purpose of this clinical trial was to determine if NAC could reduce markers of stromal-cancer metabolic heterogeneity and markers of cancer cell aggressiveness in human breast cancer.MethodsSubjects with newly diagnosed stage 0 and I breast cancer who were not going to receive neoadjuvant therapy prior to surgical resection were treated with NAC before definitive surgery to assess intra-tumoral metabolic markers. NAC was administered once a week intravenously (IV) at a dose of 150mg/kg and 600mg twice daily orally on the days not receiving NAC IV. Histochemistry (HC) for the stromal metabolic markers monocarboxylate transporter 4 (MCT4) and caveolin-1 (CAV1) and the Ki67 proliferation assay and TUNEL apoptosis assay in carcinoma cells were performed in pre- and post-NAC specimens.ResultsThe range of days on NAC was 14-27 and the mean was 19 days. Post-treatment biopsies showed significant decrease in stromal MCT4 and reduced Ki67 in carcinoma cells. NAC did not significantly change stromal CAV1 and carcinoma TUNEL staining. NAC was well tolerated.ConclusionsNAC as a single agent reduces MCT4 stromal expression, which is a marker of glycolysis in breast cancer with reduced carcinoma cell proliferation. This study suggests that modulating metabolism in the tumor microenvironment has the potential to impact breast cancer proliferation.



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