Nakamura Yasushi, Yasuoka Hironao, Tsujimoto Masahiko, Yoshidome Katsuhide, Nakahara Masaaki, Nakao Kazuyasu, Nakamura Misa, Kakudo Kennichi
Department of Pathology, Wakayama Medical University, Wakayama City, Wakayama, Japan.
Clin Cancer Res. 2006 Feb 15;12(4):1201-7. doi: 10.1158/1078-0432.CCR-05-1269.
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.
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.
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.
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.
癌细胞通过淋巴管转移至区域淋巴结是癌症进展过程中的常见步骤。近期证据表明，肿瘤产生的血管内皮生长因子C（VEGF-C）可促进淋巴管生成，进而促进淋巴转移。一氧化氮（NO）也可能增强人类癌症的转移能力。
在诱导和/或抑制NO合成后，评估MDA-MB-231乳腺癌细胞中的亚硝酸盐/硝酸盐水平及VEGF-C的产生。对长期随访的原发性人类乳腺癌进行分析，检测硝基酪氨酸（体内由NO形成过氧亚硝酸盐的生物标志物）的形成情况。分析硝基酪氨酸水平与淋巴结状态、VEGF-C免疫反应性以及其他既定临床病理变量之间的关系，以及与预后的关系。
用NO供体DETA NONOate处理后，MDA-MB-231细胞中亚硝酸盐/硝酸盐及VEGF-C的产生增加。NO合酶抑制剂N(G)-硝基-L-精氨酸甲酯消除了这种增加。在113例浸润性乳腺癌中，57.5%（65例）观察到高级别硝基酪氨酸染色。硝基酪氨酸水平与VEGF-C免疫反应性及淋巴结转移显著相关。采用Kaplan-Meier法确定的生存曲线显示，高硝基酪氨酸水平与无病生存期和总生存期缩短相关。在多变量分析中，高硝基酪氨酸水平是总生存期的显著独立预测因素。
我们的数据表明NO在体外刺激VEGF-C表达中发挥作用。其生物标志物硝基酪氨酸的形成也与VEGF-C表达及淋巴结转移相关。此外，高硝基酪氨酸水平可能是乳腺癌长期生存的重要预后因素。
