Liang Yuh-Jin, Teng Wei, Chen Chih-Li, Sun Cheng-Pu, Teng Rui-Dung, Huang Yen-Hua, Liang Kung-Hao, Chen Yi-Wen, Lin Chung-Chih, Su Chien-Wei, Tao Mi-Hua, Wu Jaw-Ching
Translational Research DivisionMedical Research DepartmentTaipei Veterans General HospitalTaipeiTaiwan, ROC.
Cancer Progression Research CenterNational Yang-Ming UniversityTaipeiTaiwan, ROC.
Hepatology. 2021 Aug;74(2):641-655. doi: 10.1002/hep.31789. Epub 2021 May 26.
PreS mutants of HBV have been reported to be associated with HCC. We conducted a longitudinal study of the role of HBV preS mutations in the development of HCC, particularly in patients with chronic hepatitis B (CHB) having low HBV DNA or alanine aminotransferase (ALT) levels, and investigated the effects of secretion-defective preS2 deletion mutant (preS2ΔMT) on hepatocyte damage in vitro and liver fibrosis in vivo.
Association of preS mutations with HCC in 343 patients with CHB was evaluated by a retrospective case-control follow-up study. Effects of preS2ΔMT on HBsAg retention, endoplasmic reticulum (ER) stress, calcium accumulation, mitochondrial dysfunction, and liver fibrosis were examined. Multivariate analysis revealed a significant association of preS mutations with HCC (HR, 3.210; 95% CI, 1.072-9.613; P = 0.037) including cases with low HBV DNA or ALT levels (HR, 2.790; 95% CI, 1.133-6.873; P = 0.026). Antiviral therapy reduced HCC risk, including cases with preS mutations. PreS2ΔMT expression promoted HBsAg retention in the ER and unfolded protein response (UPR). Transmission electron microscopic examination, MitoTracker staining, real-time ATP assay, and calcium staining of preS2ΔMT-expressing cells revealed aberrant ER and mitochondrial ultrastructure, reduction of mitochondrial membrane potential and ATP production, and calcium overload. Serum HBV secretion levels were ~100-fold lower in preS2ΔMT-infected humanized Fah-/-/ Rag2-/-/Il2rg-/- triple knockout mice than in wild-type HBV-infected mice. PreS2ΔMT-infected mice displayed up-regulation of UPR and caspase-3 and enhanced liver fibrosis.
PreS mutations were significantly associated with HCC development in patients with CHB, including those with low HBV DNA or ALT levels. Antiviral therapy reduced HCC occurrence in patients with CHB, including those with preS mutations. Intracellular accumulation of mutated HBsAg induced or promoted ER stress, calcium overload, mitochondrial dysfunction, impaired energy metabolism, liver fibrosis, and HCC.
据报道，乙肝病毒（HBV）的前S区突变与肝细胞癌（HCC）有关。我们开展了一项纵向研究，以探讨HBV前S区突变在HCC发生发展中的作用，特别是在乙肝病毒脱氧核糖核酸（HBV DNA）或丙氨酸氨基转移酶（ALT）水平较低的慢性乙型肝炎（CHB）患者中，并研究分泌缺陷型前S2缺失突变体（preS2ΔMT）对体外肝细胞损伤和体内肝纤维化的影响。
通过一项回顾性病例对照随访研究，评估了343例CHB患者中前S区突变与HCC的相关性。研究了preS2ΔMT对乙肝表面抗原（HBsAg）滞留、内质网（ER）应激、钙蓄积、线粒体功能障碍和肝纤维化的影响。多因素分析显示，前S区突变与HCC显著相关（风险比[HR]，3.210；95%置信区间[CI]，1.072 - 9.613；P = 0.037），包括HBV DNA或ALT水平较低的病例（HR，2.790；95% CI，1.133 - 6.873；P = 0.026）。抗病毒治疗降低了HCC风险，包括存在前S区突变的病例。preS2ΔMT的表达促进了HBsAg在内质网中的滞留和未折叠蛋白反应（UPR）。对表达preS2ΔMT的细胞进行透射电子显微镜检查、线粒体示踪染色、实时三磷酸腺苷（ATP）检测和钙染色，结果显示内质网和线粒体超微结构异常、线粒体膜电位和ATP生成减少以及钙超载。在感染preS2ΔMT的人源化Fah-/-/Rag2-/-/Il2rg-/-三基因敲除小鼠中，血清HBV分泌水平比感染野生型HBV的小鼠低约100倍。感染preS2ΔMT的小鼠表现出UPR和半胱天冬酶-3上调以及肝纤维化加重。
前S区突变与CHB患者的HCC发生发展显著相关，包括HBV DNA或ALT水平较低的患者。抗病毒治疗降低了CHB患者的HCC发生率，包括存在前S区突变的患者。突变型HBsAg在细胞内的蓄积诱导或促进了内质网应激、钙超载、线粒体功能障碍、能量代谢受损、肝纤维化和HCC。
