Division of Biochemistry, Faculty of Pharmacy and Graduate School of Pharmaceutical Science, Keio University, Tokyo, 105-8512, Japan.
Department of Surgery, National Center for Global Health and Medicine, Tokyo, 162-8655, Japan.
Sci Rep. 2021 May 19;11(1):10589. doi: 10.1038/s41598-021-89963-1.
Liver cancer is the fourth leading cause of cancer-related death. Hepatocellular carcinoma (HCC) is a primary liver cancer that results from chronic hepatitis caused by multiple predisposing factors such as viral infection, alcohol consumption, and non-alcoholic fatty liver disease. Accumulating studies have indicated that dysfunction of the gut epithelial barrier and hepatic translocation of gut microbes may be implicated in the pathogenesis of HCC. However, the translocated bacteria in HCC patients remains unclear. Here, we characterised tumour-associated microbiota in patients with liver cancer and focused on HCC. We observed that the number of amplicon sequence variants in tumour-associated microbiota was significantly higher compared with that in non-tumour regions of the liver. The tumour-associated microbiota consisted of Bacteroidetes, Firmicutes, and Proteobacteria as the dominant phyla. We identified an unclassified genus that belonged to the Bacteroides, Romboutsia, uncultured bacterium of Lachnospiraceae as a signature taxon for primary liver cancer. Additionally, we identified Ruminococcus gnavus as a signature taxon for HCC patients infected with hepatitis B and/or hepatitis C viruses. This study suggests that tumour microbiota may contribute to the pathology of HCC.
肝癌是癌症相关死亡的第四大主要原因。肝细胞癌 (HCC) 是一种原发性肝癌，由多种诱发因素引起的慢性肝炎导致，如病毒感染、饮酒和非酒精性脂肪肝疾病。越来越多的研究表明，肠道上皮屏障功能障碍和肠道微生物向肝脏的易位可能与 HCC 的发病机制有关。然而，肝癌患者易位的细菌仍不清楚。在这里，我们对肝癌患者的肿瘤相关微生物群进行了特征描述，并重点研究了 HCC。我们观察到，肿瘤相关微生物群中的扩增子序列变异数明显高于肝脏非肿瘤区域。肿瘤相关微生物群主要由拟杆菌门、厚壁菌门和变形菌门组成。我们鉴定出一个未分类的属，属于拟杆菌门、罗氏菌属、毛螺菌科未培养菌，是原发性肝癌的特征分类群。此外，我们还鉴定出直肠真杆菌是乙型肝炎和/或丙型肝炎病毒感染的 HCC 患者的特征分类群。本研究表明，肿瘤微生物群可能有助于 HCC 的病理学。
