血液代謝體變化和肝細胞癌致癌進程的關係

Abstract

背景及目的：過去研究發現B型肝炎感染者及未感染者，肝細胞癌患者及未發生肝細胞癌者體內的代謝情況會有明顯不同，因此我們認為B型肝炎病毒造成慢性感染者體內代謝的變化和後續發展成肝細胞癌有關。於是本研究利用回溯性長期多時點研究設計來探討B型肝炎病毒帶原者於發生肝細胞癌之前長期代謝體輪廓的變化。 材料與方法：本研究從過去1143人的病例對照世代資料庫中隨機選取71名肝細胞癌病患及71名未發病個案，該病例對照世代樣本皆為B型肝炎病毒帶原且年齡介於30-65歲之男性個案。71對樣本依據進入研究之年份及年齡進行個別配對，並於1989-2006年的追蹤時間中依據抽血時間進行2-6個時點的配對(追蹤時間中位數：8.69年)。血漿的代謝體實驗是利用一維度氫原子NMR(nuclear magnetic resonance)質譜來進行，並且會利用PCA(principal component analysis)及OPLS- DA(orthogonal projections to latent structures discriminant analysis)的方式去進行分組的鑑別。後續會利用GEE(generalized estimating equation)模式去探討長期的代謝體變化和肝細胞癌及病毒因子間的關係，同時也會利用代謝分子群集分析來辨識何種生物路徑受到影響。 結果：從基線的檢定可以發現，formate、citrate、pyruvate、tyrosine、isopropanol、creatinine、valine及leucine等8個代謝小分子顯著於兩組的分布不同(P值皆≤0.0649)，表示能量代謝及支鍊族胺基酸的代謝可能受到B型肝炎病毒影響。具體而言，formate、citrate、pyruvate等能量代謝相關的代謝小分子會顯著的於肝細胞癌組增加；而valine及leucine支鍊族胺基酸會顯著的於肝細胞癌組降低。能量代謝相關之代謝分子濃度的上升和B型肝炎病毒之長期病毒量有顯著的正相關。 結論：本研究發現能量代謝路徑相關分子濃度上升及支鏈族胺基酸的代謝分子濃度下降，可能和發展成B型肝炎相關肝細胞癌有關。

Background & Aims: Studies have shown distinct metabolic profiles in hepatitis B virus (HBV)-infected vs. uninfected persons, and in patients with hepatocellular carcinoma (HCC) vs. those without. We hypothesized that changes in metabolic pathways may mediate the effect of chronic HBV infection during the development of HCC. A retrospective longitudinal repository study was designed to longitudinally explore associations between metabolomics profiles and viral factors and HCC risk. Materials and Methods: In a case-cohort study database of 1143 hepatitis B surface antigen-positive men aged 30-65 years, we randomly selected 71 HCC cases and 71 matched controls with blood drawn 2 to 6 times before diagnosis of HCC from 1989 to 2006 (median follow-up: 8.69 years). Cases and controls were matched for by entry year, age at recruitment, and blood collection time. Plasma metabolomics profiling was performed by 1D 1H NMR (nuclear magnetic resonance) spectroscopy. PCA and OPLS-DA was used in global profiles of pattern recognition. Generalized estimating equation (GEE) models were performed to explore the longitudinal relationship between specific metabolites and HCC or viral factors. Metabolite set enrichment analysis was used to identify and interpret patterns of human metabolite concentration changes in a biological pathway. Result: We showed that baseline plasma metabolomics patterns were significantly different between HCC cases and controls. Eight baseline discriminatory metabolites (including formate, citrate, pyruvate, tyrosine, isopropanol, creatinine, valine, and leucine) were associated with HCC (all p-values≤0.0649), indicating that diverse pathways were altered, including energy metabolism and branched-chain amino acid metabolism. Specifically, metabolites related to energy metabolism, including citrate, pyruvate, and formate were significantly increased in the HCC cases vs. controls, while metabolites related to branched-chain amino acid metabolism, including valine and leucine were significantly were decreased in the HCC cases vs. controls. The serum concentrations of energy related metabolites increased and this up-regulation trend associated with longitudinal HBV viral load. Conclusion: This study showed that metabolic alterations, including increased energy metabolism and decreased branched-chain amino acid group, may be associated with the development of HBV-related HCC risk.