Oxidized redox state, a new potential biomarker for prostate cancer progression

 描述（由申请人提供）：前列腺癌（PCa）是全球范围内日益常见的恶性肿瘤;进展为晚期癌症是高度不可预测的，因此需要新的临床相关生物标志物或诊断工具。更好地了解PCa的病理进展将有助于开发更敏感和特异的生物标志物。根据对人前列腺癌组织分析的初步结果，与邻近良性组织相比，具有高Gleason评分的原发性前列腺癌和转移性前列腺癌中氧化还原状态和硫氧还蛋白1（Trx 1）蛋白水平的翻译后修饰显著增加。我们推测，氧化还原状态的增加是由于前列腺癌的氧化还原失衡，导致活性氧/活性氮的产生增加，氧化DNA损伤，肿瘤抑制基因突变，表观遗传变化，以及随后的前列腺癌进展。为了充分理解氧化的氧化还原状态和PCa进展的关系，第一步涉及确定患者样品中氧化的氧化还原状态与PCa进展的相关性。在特定目标1中，将构建具有不同病理阶段的人PCA-肿瘤微阵列，用氧化损伤产物染色，并使用Vectra/Nuance系统进行分析。此外，与相邻良性上皮前列腺组织相比，将在具有不同病理阶段的人前列腺冷冻组织中测量硫醇氧化还原对。明确PCa的氧化还原状态及其与疾病分期的相关性 是必要的第一步，以确定1）氧化的氧化还原状态是否可以潜在地用作PCa诊断的生物标志物和2）氧化的氧化还原状态是否是PCa进展的原因或结果。目标1中氧化还原状态的生化分析是时间和劳动密集型的，并且需要大量的组织。为了克服这些问题，Special Aim 2将评估TEMPOL增强MRI是否可能用于诊断体内前列腺癌的细胞内氧化还原状态。TEMPOL可以通过不同的氧化剂氧化成相应的氧代铵阳离子，并且其顺磁性可以通过MRI捕获。氧化组织将比还原组织表现出更长寿命的MRI信号。我们将用原位异种移植LNCaP-luc-M6或PC 3 M-luc-C6细胞扫描裸鼠，以评估TEMPOL增强MRI的可能性和有效性。据我们所知，本提案将是第一个1）尝试将组织氧化还原状态与患者样品中PCa的侵袭性相关联和2）使用尖端技术，TEMPOL增强MRI来可视化氧化还原状态和PCa的诊断。在完成这些研究后，更好地了解PCa病理/代谢进展可能有助于开发更敏感、更相关和更特异的生物标志物，用于早期预测或预后临床癌症进展的患者。

 DESCRIPTION (provided by applicant): Prostate cancer (PCa) is an increasingly common malignancy worldwide; progression to advanced cancer is highly unpredictable, resulting in a need for new clinically relevant biomarkers or diagnosis tools. A better understanding of PCa pathologic progression would allow development of more sensitive and specific biomarkers. Based on preliminary results from analyses of human PCa tissues, oxidized redox state and posttranslational modification of thioredoxin 1 (Trx1) protein levels were significantly increased in primary PCa with high Gleason scores and metastatic PCa in comparison to adjacent benign tissues. We hypothesize that increased oxidized redox state is contributed to redox imbalance in PCa, leading to increased production of reactive oxygen species/reactive nitrogen species, oxidative DNA damage, mutation of tumor suppressor genes, epigenetic changes, and subsequent PCa progression. To fully understand the relationship of oxidized redox state and PCa progression, a first step involves determining the correlation of oxidized redox state with PCa progression in patient samples. In Specific Aim 1, human PCa-tumor microarrays with different pathological stages will be constructed, stained with oxidative damage products and analyzed using Vectra/Nuance system. Additionally, thiol redox couples will be measured in human prostate frozen tissues with different pathological stages compared to adjacent benign epithelial prostate tissues. Defining the redox state of PCa and its correlation with disease stage is a necessary first step to determine 1) if oxidized redox state may potentially be used as biomarker for PCa diagnosis and 2) whether oxidized redox state is the cause or consequence of PCa progression. Biochemical analyses of redox state in Aim 1 are time-and labor-intensive and require a large amount of tissues. To overcome these problems, Specific Aim 2 will evaluate if TEMPOL-enhanced MRI could potentially be used in the diagnosis of intracellular redox state of prostate cancer in vivo. TEMPOL can undergo oxidation to the corresponding oxoammonium cation by variant oxidants and its paramagnetism property can be captured by MRI. Oxidizing tissues will exhibit longer-lived MRI signal than reducing tissues. We will scan nude mice with orthotopic xenograft transplant LNCaP-luc-M6 or PC3M-luc-C6 cells to evaluate the possibility and validity of TEMPOL-enhanced MRI. To our knowledge, the present proposal will be the first to 1) attempting correlate tissue redox status with the aggressiveness of PCa in patient samples and 2) use cutting edge technique, TEMPOL enhanced MRI to visualize redox state and diagnosis of PCa. Upon completion of these studies, a better understanding of PCa pathologic/metabolic progression may allow development of more sensitive, more relevant, and more specific biomarkers for early prediction or prognosis of those patients destined for clinical cancer progression.