Jin Jonghwa, Son Minsoo, Kim Hyeyoon, Kim Hyeyeon, Kong Seong-Ho, Kim Hark Kyun, Kim Youngsoo, Han Dohyun
Department of Biomedical Engineering, Seoul National University College of Medicine, 28 Yongon-Dong, Jongno-gu, Seoul, Republic of Korea; Institute of Medical & Biological Engineering, Seoul National University College of Medicine, 28 Yongon-Dong, Jongno-gu, Seoul, Republic of Korea.
Proteomics core facility, Biomedical Research Institute, Seoul National University Hospital, 71 Daehak-ro, Jongno-gu, Seoul, Republic of Korea.
Clin Biochem. 2018 Jun;56:55-61. doi: 10.1016/j.clinbiochem.2018.04.003. Epub 2018 Apr 11.
Malignant ascites is a sign of peritoneal seeding, which is one of the most frequent forms of incurable distant metastasis. Because the development of malignant ascites is associated with an extremely poor prognosis, determining whether it resulted from peritoneal seeding has critical clinical implications in diagnosis, choice of treatment, and active surveillance. At present, the molecular characterizations of malignant ascites are especially limited in case of gastric cancer. We aimed to identify malignant ascites-specific proteins that may contribute to the development of alternative methods for diagnosis and therapeutic monitoring and also increase our understanding of the pathophysiology of peritoneal seeding.
DESIGN & METHODS: First, comprehensive proteomic strategies were employed to construct an in-depth proteome of ascitic fluids. Label-free quantitative proteomic analysis was subsequently performed to identify candidates that can differentiate between malignant ascitic fluilds of gastric cancer patients from benign ascitic fluids. Finally, two candidate proteins were verified by ELISA in 84 samples with gastric cancer or liver cirrhosis.
Comprehensive proteome profiling resulted in the identification of 5347 ascites proteins. Using label-free quantification, we identified 299 proteins that were differentially expressed in ascitic fluids between liver cirrhosis and stage IV gastric cancer patients. In addition, we identified 645 proteins that were significantly expressed in ascitic fluids between liver cirrhosis and gastric cancer patients with peritoneal seeding. Finally, Gastriscin and Periostin that can distinguish malignant ascites from benign ascites were verified by ELISA.
This study identified and verified protein markers that can distinguish malignant ascites with or without peritoneal seeding from benign ascites. Consequently, our results could be a significant resource for gastric cancer research and biomarker discovery in the diagnosis of malignant ascites.
恶性腹水是腹膜种植的征象，腹膜种植是不可治愈的远处转移最常见的形式之一。由于恶性腹水的发生与极差的预后相关，因此确定其是否由腹膜种植引起在诊断、治疗选择和主动监测方面具有关键的临床意义。目前，在胃癌病例中，恶性腹水的分子特征尤其有限。我们旨在鉴定恶性腹水特异性蛋白，这些蛋白可能有助于开发诊断和治疗监测的替代方法，并增进我们对腹膜种植病理生理学的理解。
首先，采用综合蛋白质组学策略构建腹水的深度蛋白质组。随后进行无标记定量蛋白质组分析，以鉴定能够区分胃癌患者恶性腹水与良性腹水的候选蛋白。最后，通过酶联免疫吸附测定法（ELISA）在84例胃癌或肝硬化样本中验证了两种候选蛋白。
综合蛋白质组分析鉴定出5347种腹水蛋白。通过无标记定量分析，我们鉴定出299种在肝硬化患者和IV期胃癌患者的腹水中差异表达的蛋白。此外，我们还鉴定出645种在肝硬化患者和有腹膜种植的胃癌患者的腹水中显著表达的蛋白。最后，通过ELISA验证了能区分恶性腹水与良性腹水的胃泌素和骨膜蛋白。
本研究鉴定并验证了可区分有无腹膜种植的恶性腹水与良性腹水的蛋白标志物。因此，我们的研究结果可能成为胃癌研究和恶性腹水诊断中生物标志物发现的重要资源。
