Akdeniz University, Medical Faculty, Department of Pharmacology, 07070 Antalya, Turkey.
Vascul Pharmacol. 2013 Sep-Oct;59(3-4):103-11. doi: 10.1016/j.vph.2013.07.008. Epub 2013 Aug 7.
Although the oxidative stress and inflammation are closely related with breast cancer, there is no study directly examining the possible changes in vascular functions in the presence of breast carcinoma. The goal of the present study was to evaluate changes in vascular reactivity in tumor-bearing mice. In this study, highly metastatic breast carcinoma cells which were derived from liver or brain metastasis of 4T1 murine breast carcinoma (4TLM and 4TBM, respectively), and 67NR cells which were tumorigenic but non-metastatic cells were used. Female Balb-c mice 8-10weeks old were divided into following groups: (1) control, (2) injected with 67NR, (3) injected with 4TLM, and (4) injected with 4TBM orthotopically. Thoracic aorta was removed 23-25days after injection of tumor cells. Isometric tension studies were performed in response to potassium chloride (KCl), phenylephrine (Phe), acetylcholine (ACh, an endothelium-dependent vasodilator), and sodium nitroprusside (SNP, an endothelium-independent vasodilator). Endothelial nitric oxide synthase (eNOS), phosphorylated eNOS (Ser 1177) (p-eNOS), gp91(phox), and tumor necrosis factor-α (TNF-α) expressions in aortic tissues were demonstrated by immunohistochemistry. The level of TNF-α in vascular tissue was measured by ELISA. The presence of tumor was resulted in significant inhibition of response to ACh in both 4TLM and 4TBM injected mice, but not 67NR injected mice. Furthermore, both KCl and Phe-induced contraction of thoracic aorta was not changed significantly in tumor-bearing animals. eNOS and p-eNOS expressions decreased while gp91(phox) and TNF-α expressions increased in endothelium of 4TLM and 4TBM mice compared to 67NR injected and control mice. Moreover, TNF-α levels of thoracic aorta in mice with metastatic breast carcinoma were significantly higher than that of 67NR mice. Tumor-induced endothelial dysfunction determined by ACh-induced relaxation improved by superoxide dismutase (SOD), apocynin (a NADPH oxidase inhibitor), and infliximab (a TNF-α monoclonal antibody). The findings of this study suggest that the presence of metastatic breast carcinoma may cause a significant reduction in endothelium-dependent relaxation of thoracic aorta via NADPH oxidase-mediated oxidative stress and TNF-α production.
尽管氧化应激和炎症与乳腺癌密切相关，但目前尚无研究直接检测乳腺癌存在时血管功能的可能变化。本研究旨在评估荷瘤小鼠血管反应性的变化。在这项研究中，使用了源自肝或脑转移的 4T1 乳腺癌（4TLM 和 4TBM，分别）的高转移性乳腺癌细胞以及肿瘤形成但无转移的 67NR 细胞。8-10 周龄的雌性 Balb-c 小鼠分为以下几组：（1）对照组，（2）注射 67NR，（3）注射 4TLM，和（4）注射 4TBM 原位。注射肿瘤细胞 23-25 天后取出胸主动脉。对氯化钾（KCl）、苯肾上腺素（Phe）、乙酰胆碱（ACh，一种内皮依赖性血管舒张剂）和硝普钠（SNP，一种内皮非依赖性血管舒张剂）的等长张力研究。通过免疫组织化学法显示主动脉组织中内皮型一氧化氮合酶（eNOS）、磷酸化 eNOS（Ser1177）（p-eNOS）、gp91（phox）和肿瘤坏死因子-α（TNF-α）的表达。通过 ELISA 测量血管组织中 TNF-α 的水平。4TLM 和 4TBM 注射小鼠的肿瘤存在导致对 ACh 反应明显抑制，但 67NR 注射小鼠没有。此外，荷瘤动物的 KCl 和 Phe 诱导的胸主动脉收缩没有明显变化。与 67NR 注射和对照组小鼠相比，4TLM 和 4TBM 小鼠的 eNOS 和 p-eNOS 表达降低，而 gp91（phox）和 TNF-α 表达增加。此外，转移性乳腺癌小鼠的胸主动脉 TNF-α 水平明显高于 67NR 小鼠。超氧化物歧化酶（SOD）、阿朴肉桂酸（NADPH 氧化酶抑制剂）和英夫利昔单抗（TNF-α 单克隆抗体）可改善肿瘤诱导的内皮功能障碍，由 ACh 诱导的松弛来确定。本研究结果表明，转移性乳腺癌的存在可能通过 NADPH 氧化酶介导的氧化应激和 TNF-α 产生导致胸主动脉内皮依赖性松弛明显减少。
