氧化应激被认为是肾细胞癌（RCC）发展和进展的因素。确定蛋白质的氧化和硝化修饰并定义其在透明细胞肾癌（ccRCC）中的作用可以帮助制定靶向治疗策略以减轻蛋白质损伤。本研究旨在调查氧化/硝化应激的状态并探讨其在发展和进展过程中的作用。研究组由48例新诊断的ccRCC和30例健康对照组组成。测定了氧化应激标志物-高级氧化蛋白产物（AOPP）、巯基、Amadori反应产物、3-硝基酪氨酸、硝酸盐/亚硝酸盐、丙二醛（MDA）、4-羟基-2-己烯酰肼和总抗氧化能力（TAC）的血清水平。此外，评估了肿瘤根据TNM分级、组织学分级以及血管侵袭对应激标志物水平的影响。ccRCC组的Amadori产物、3-硝基酪氨酸和硝酸盐/亚硝酸盐水平升高，而巯基和TAC水平降低。AOPP、Amadori和3-硝基酪氨酸水平随肿瘤的病理分期增加而增加，巯基和TAC水平降低。在对肿瘤进行进一步的组织学评估时，我们发现巯基水平降低，MDA水平增加。在有血管侵袭的患者中，硝酸盐/亚硝酸盐和MDA水平明显升高，相比之下，无血管侵袭的患者中这些水平较低。氧化应激随根据TNM和组织学分级评估的疾病进展而增加。这些结果表明ccRCC中存在系统性氧化应激，提示抗氧化剂的治疗应用。

Oxidative stress is believed to be a factor in the development and progression of renal cell carcinoma (RCC). The identification of the oxidative and nitrosative modification of proteins and the definition of their roles in clear cell RCC (ccRCC) may be helpful in the elaboration of targeted therapeutic approaches to mitigate protein damage. This study aimed to investigate the status of oxidative/nitrosative stress and to explore its role in the development and progression. The studied group consisted of 48 newly diagnosed ccRCC and 30 healthy controls. Serum levels of oxidative stress markers-advanced oxidation protein products (AOPP), thiol groups, Amadori reaction products, 3-nitrotyrosine, nitrate/nitrite, malondialdehyde (MDA), 4-hydroxy-2-nonenal and total antioxidant capacity (TAC)-were determined. Additionally, associations between tumour stage assessed according to TNM classification, histological grade, and the effect of the presence of angioinvasion on the level of stress markers were evaluated. The levels of Amadori products, 3-nitrotyrosine, and nitrate/nitrite were elevated, while the levels of thiol groups and TAC decreased in the ccRCC group. The levels of AOPP, Amadori, and 3-nitrotyrosine increased, and thiol groups and TAC levels decreased with the increasing pathological stage of the tumour. In the case of advanced histological assessment of the tumour, we found decreasing levels of thiol groups and increasing levels of MDA. In patients with angioinvasion, nitrate/nitrite and MDA levels were significantly elevated compared to those in patients without angioinvasion. Oxidative stress increased with the progression of the disease assessed according to the TNM and histological grade. These results demonstrate systemic oxidative stress in ccRCC, suggesting the therapeutic application of antioxidants.