PURPOSE: Metastasis to regional lymph nodes through the lymphatic vessels is a common step in the progression of cancer. Recent evidence suggests that tumor production of vascular endothelial growth factor-C (VEGF-C) promotes lymphagiogenesis, which in turn promotes lymphatic metastasis. Nitric oxide (NO) may also increase metastatic ability in human cancers. EXPERIMENTAL DESIGN: Nitrite/nitrate levels and VEGF-C production were assessed in MDA-MB-231 breast cancer cells after induction and/or inhibition of NO synthesis. Formation of nitrotyrosine, a biomarker for peroxynitrate formation from NO in vivo, was analyzed in primary human breast carcinoma with long-term follow-up. The relationship between nitrotyrosine levels and lymph node status, VEGF-C immunoreactivity, and other established clinicopathologic variables, as well as prognosis, was analyzed. RESULTS: Production of nitrite/nitrate and VEGF-C in MDA-MB-231 cells was increased by treatment with the NO donor DETA NONOate. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester eliminated this increase. High-grade nitrotyrosine staining was observed in 57.5% (65 of 113) of the invasive breast carcinomas. Nitrotyrosine levels were significantly correlated with VEGF-C immunoreactivity and lymph node metastasis. Survival curves determined by the Kaplan-Meier method showed that high nitrotyrosine levels were associated with reduced disease-free and overall survival. In multivariate analysis, high nitrotyrosine levels emerged as a significant independent predictor for overall survival. CONCLUSIONS: Our data showed a role for NO in stimulating VEGF-C expression in vitro. Formation of its biomarker nitrotyrosine was also correlated with VEGF-C expression and lymph node metastasis. Furthermore, high nitrotyrosine levels may serve as a significant prognostic factor for long-term survival in breast cancer.
PURPOSE: Metastasis to regional lymph nodes through the lymphatic vessels is a common step in the progression of cancer. Recent evidence suggests that tumor production of vascular endothelial growth factor-C (VEGF-C) promotes lymphagiogenesis, which in turn promotes lymphatic metastasis. Nitric oxide (NO) may also increase metastatic ability in humancancers. EXPERIMENTAL DESIGN:Nitrite/nitrate levels and VEGF-C production were assessed in MDA-MB-231 breast cancer cells after induction and/or inhibition of NO synthesis. Formation of nitrotyrosine, a biomarker for peroxynitrate formation from NO in vivo, was analyzed in primary humanbreast carcinoma with long-term follow-up. The relationship between nitrotyrosine levels and lymph node status, VEGF-C immunoreactivity, and other established clinicopathologic variables, as well as prognosis, was analyzed. RESULTS: Production of nitrite/nitrate and VEGF-C in MDA-MB-231 cells was increased by treatment with the NO donorDETA NONOate. The NO synthase inhibitor N(G)-nitro-l-arginine methyl ester eliminated this increase. High-grade nitrotyrosine staining was observed in 57.5% (65 of 113) of the invasive breast carcinomas. Nitrotyrosine levels were significantly correlated with VEGF-C immunoreactivity and lymph node metastasis. Survival curves determined by the Kaplan-Meier method showed that high nitrotyrosine levels were associated with reduced disease-free and overall survival. In multivariate analysis, high nitrotyrosine levels emerged as a significant independent predictor for overall survival. CONCLUSIONS: Our data showed a role for NO in stimulating VEGF-C expression in vitro. Formation of its biomarker nitrotyrosine was also correlated with VEGF-C expression and lymph node metastasis. Furthermore, high nitrotyrosine levels may serve as a significant prognostic factor for long-term survival in breast cancer.
Authors: Ubaldo E Martinez-Outschoorn; Renee M Balliet; Dayana B Rivadeneira; Barbara Chiavarina; Stephanos Pavlides; Chenguang Wang; Diana Whitaker-Menezes; Kristin M Daumer; Zhao Lin; Agnieszka K Witkiewicz; Neal Flomenberg; Anthony Howell; Richard G Pestell; Erik S Knudsen; Federica Sotgia; Michael P Lisanti Journal: Cell Cycle Date: 2010-08-28 Impact factor: 4.534