Background/Objective:Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer death and tumors with an extremely poor prognosis. In the present study, novel biomarker candidates useful for the early diagnosis and prognosis of human invasive PDAC were investigated.Methods:Biomarker candidates were first selected based on the proteomic/bioinformatic and clinico-pathological analyses of 10 and 100 patients with PDAC, respectively, operated at Osaka Metropolitan University Hospital (Exp. 1). Next, the expression and secretion of the target protein and its EV mRNA were investigated in pancreatic cancer cells in vitro and in a Balb/c nude mouse model. In addition, the protein and EV mRNA levels of candidate molecules were measured in the blood serum of 36 PDAC and 10 IPMN patients, and diagnostic significance was assessed (Exp. 2).Results:A significant elevation of peroxiredoxin 3 (PRX3), a mitochondrial matrix protein, was found in PDAC via LC-Ms/Ms analysis. In Exp. 1, PRX3 overexpression was found in PDAC and PanIN lesions and was associated with a tumor infiltrative growth pattern (INFc) and poor overall 1-year patient survival. The prognostic value was significantly improved when PRX3 was combined with serum SPan-1 and DUPAN-2 markers in survival analyses. Furthermore, the PRX3 protein and its extracellular vesicle (EV: exosome and oncosome)-incorporated mRNA were secreted at detectable levels from PANC-1, MIAPaCa-2, and SW1990 cells into the blood of Balb/c nude mice bearing tumors. The overexpression of PRX3 was positively correlated with that of cancer stem cell marker CD44 variant 9 (CD44v9), P-Nrf2, and FOXO3a, as well as the generation of reactive oxygen species. In Exp. 2, a significant increase in PRX3 protein and EV mRNA was detected in the blood serum of PDAC subjects compared to IPMN patients and healthy controls. Significantly higher PRX3 protein levels were found in the IPMN group. The elevation of PRX3 EV mRNA was significantly associated with poor patient survival.Conclusions:These results indicate that PRX3 may become a novel early biomarker for PDAC diagnosis and prognosis.
背景/目的：胰腺导管腺癌（PDAC）是导致癌症死亡的主要原因之一，其预后极差。本研究旨在探索可用于人类侵袭性PDAC早期诊断及预后评估的新型生物标志物候选物。 方法：首先基于大阪公立大学医院手术治疗的10例及100例PDAC患者的蛋白质组学/生物信息学及临床病理学分析，初步筛选出候选生物标志物（实验1）。随后，在体外胰腺癌细胞及Balb/c裸鼠模型中，研究了目标蛋白及其细胞外囊泡（EV）mRNA的表达与分泌情况。此外，检测了36例PDAC患者及10例胰腺导管内乳头状黏液性肿瘤（IPMN）患者血清中候选分子的蛋白及EV mRNA水平，并评估其诊断意义（实验2）。 结果：通过液相色谱-串联质谱（LC-MS/MS）分析发现，线粒体基质蛋白过氧化物氧化还原酶3（PRX3）在PDAC中显著升高。实验1显示，PRX3在PDAC及胰腺上皮内瘤变（PanIN）病变中过表达，且与肿瘤浸润性生长模式（INFc）及患者1年总生存率较差相关。在生存分析中，将PRX3与血清标志物SPan-1及DUPAN-2联合使用时，其预后评估价值显著提升。此外，PANC-1、MIAPaCa-2及SW1990细胞可将PRX3蛋白及其细胞外囊泡（包括外泌体及肿瘤小体）包裹的mRNA分泌至荷瘤Balb/c裸鼠血液中，且达到可检测水平。PRX3的过表达与癌症干细胞标志物CD44变异体9（CD44v9）、磷酸化核因子E2相关因子2（P-Nrf2）、FOXO3a以及活性氧的生成呈正相关。实验2中，与IPMN患者及健康对照组相比，PDAC患者血清中PRX3蛋白及EV mRNA水平显著升高。IPMN组患者的PRX3蛋白水平亦显著较高。PRX3 EV mRNA的升高与患者不良生存率显著相关。 结论：这些结果表明，PRX3可能成为PDAC诊断及预后评估的新型早期生物标志物。
肿瘤(癌症)患者之家