Oral supplementation with branched-chain amino acid granules prevents hepatocarcinogenesis in patients with hepatitis C-related cirrhosis: A propensity score analysis

Multiple roles of branched-chain amino acid metabolism in tumour progression

Metabolic reprogramming enables tumour cells to sustain their continuous proliferation and adapt to the ever-changing microenvironment. Branched-chain amino acids (BCAAs) and their metabolites are involved in intracellular protein synthesis and catabolism, signal transduction, epigenetic modifications, and the maintenance of oxidative homeostasis. Alterations in BCAA metabolism can influence the progression of various tumours. However, how BCAA metabolism is dysregulated differs among depending on tumour type; for example, it can manifest as decreased BCAA metabolism leading to BCAA accumulation, or as enhanced BCAA uptake and increased catabolism. In this review, we describe the role of BCAA metabolism in the progression of different tumours. As well as discuss how BCAA metabolic reprogramming drives tumour therapy resistance and evasion of the antitumour immune response, and how these pro-cancer effects are achieved in part by activating the mTORC signalling pathway. In-depth investigations into the potential mechanisms by which BCAA metabolic reprogramming affects tumorigenesis and tumour progression can enhance our understanding of the relationship between metabolism and cancer and provide new strategies for cancer therapy.

Serum Branched-Chain Amino Acids and Long-Term Complications of Liver Cirrhosis: Evidence from a Population-Based Prospective Study

BACKGROUND AND AIMS

The role of serum branched-chain amino acids (BCAAs) in long-term liver cirrhosis complication events remains unclear. We aimed to evaluate the associations between serum BCAAs and the risk of liver-related events.

METHODS

We included a total of 64,005 participants without liver cirrhosis complication events at baseline from the UK Biobank. Cox proportional hazards regression models were utilized to estimate multivariable hazard ratios (HRs) and 95% CIs for the incidence of liver cirrhosis complication events, adjusting for potential confounders, including sociodemographic and lifestyle factors. Relationships between serum BCAAs and liver cirrhosis complications were examined using nonparametrically restricted cubic spline regression.

RESULTS

During a median follow-up of 12.7 years, 583 participants developed liver cirrhosis complication events. The multivariable Cox regression model suggested that total BCAAs (HR  =  0.88, 95% CI 0.82-0.95), serum leucine (HR  =  0.88, 95% CI 0.81-0.95), serum isoleucine (HR  =  0.88, 95% CI 0.82-0.96), and serum valine (HR  =  0.87, 95% CI 0.82-0.96) were all independent protective factors for liver cirrhosis complications after adjustment for sociodemographic and lifestyle factors. Cox models with restricted cubic splines showed U-shaped associations between serum valine and liver cirrhosis complication incidence. Serum total BCAA and isoleucine concentrations might reduce the risk of liver cirrhosis complications by raising the risk of (type 2 diabetes mellitus) T2DM.

CONCLUSION

Lower serum BCAA levels exacerbate the long-term risk of liver cirrhosis complications. Future studies should confirm these findings and identify the biological pathways of these associations.

Systematic review with meta-analysis: Branched-chain amino acid supplementation in liver disease

BACKGROUND

Dietary supplementation with branched-chain amino acids (BCAA) is often used in cirrhotic patients to improve nutritional status. We wanted to explore the evidence for BCAA supplementation in chronic liver disease.

METHODS

We searched MEDLINE and EMBASE for studies with BCAA supplementation with the presence of a disease-control group (placebo or no intervention) using search terms 'liver cirrhosis', 'hepatocellular carcinoma', 'branched chain amino acids' and relevant synonyms. Risk of bias was assessed using ROBINS-I and RoB 2.0 tools. Meta-analyses were performed with a random-effects model. Results were reported following EQUATOR guidelines.

RESULTS

Of 3378 studies screened by title and abstract, 54 were included (34 randomized controlled trials, 5 prospective case-control studies, 13 retrospective case-control studies: in total 2308 patients BCAA supplementation, 2876 disease-controls). Risk of bias was high/serious for almost all studies. According to meta-analyses, long-term (at least 6 months) BCAA supplementation in cirrhotic patients significantly improved event-free survival (p = .008; RR .61 95% CI .42-.88) and tended to improve overall survival (p = .05; RR .58 95% CI .34-1.00). Two retrospective studies suggested the beneficial effects during sorafenib for hepatocellular carcinoma. Available studies reported no beneficial effects or contradictory results of BCAA after other specific therapeutic interventions (resection or radiological interventions for hepatocellular carcinoma, liver transplantation, paracentesis or variceal ligation). No convincing beneficial effects of BCAA supplementation on liver function, nutritional status or quality of life were found. No study reported serious side effects of BCAA.

CONCLUSIONS

Prophylactic BCAA supplementation appears safe and might improve survival in cirrhotic patients.

Effect of dietary branched chain amino acids on liver related mortality: Results from a large cohort of North American patients with advanced HCV infection

Branched chain amino acids (BCAA) supplementation may reduce the incidence of liver failure and hepatocellular carcinoma in patients with cirrhosis. We aimed to determine whether long-term dietary intake of BCAA is associated with liver-related mortality in a well-characterized cohort of North American patients with advanced fibrosis or compensated cirrhosis. We performed a retrospective cohort study using extended follow-up data from the Hepatitis C Antiviral Long-term Treatment against Cirrhosis (HALT-C) Trial. The analysis included 656 patients who completed two Food Frequency Questionnaires. The primary exposure was BCAA intake measured in grams (g) per 1000 kilocalories (kcal) of energy intake (range 3.0-34.8 g/1000 kcal). During a median follow-up of 5.0 years, the incidence of liver-related death or transplantation was not significantly different among the four quartiles of BCAA intake before and after adjustment of confounders (AHR 1.02, 95% CI 0.81-1.27, P-value for trend = 0.89). There remains no association when BCAA was modeled as a ratio of BCAA to total protein intake or as absolute BCAA intake. Finally, BCAA intake was not associated with the risk of hepatocellular carcinoma, encephalopathy or clinical hepatic decompensation. We concluded that dietary BCAA intake was not associated with liver-related outcomes in HCV-infected patients with advanced fibrosis or compensated cirrhosis. The precise effect of BCAA in patients with liver disease warrants further study.

Diet high in branched-chain amino acid promotes PDAC development by USP1-mediated BCAT2 stabilization

BCAT2-mediated branched-chain amino acid (BCAA) catabolism is critical for pancreatic ductal adenocarcinoma (PDAC) development, especially at an early stage. However, whether a high-BCAA diet promotes PDAC development in vivo, and the underlying mechanism of BCAT2 upregulation, remain undefined. Here, we find that a high-BCAA diet promotes pancreatic intraepithelial neoplasia (PanIN) progression in LSL-Kras^G12D/+; Pdx1-Cre (KC) mice. Moreover, we screened with an available deubiquitylase library which contains 31 members of USP family and identified that USP1 deubiquitylates BCAT2 at the K229 site. Furthermore, BCAA increases USP1 protein at the translational level via the GCN2-eIF2α pathway both in vitro and in vivo. More importantly, USP1 inhibition recedes cell proliferation and clone formation in PDAC cells and attenuates pancreas tumor growth in an orthotopic transplanted mice model. Consistently, a positive correlation between USP1 and BCAT2 is found in KC; LSL-Kras^G12D/+; p53^flox/+; Pdx1-Cre mice and clinical samples. Thus, a therapeutic targeting USP1-BCAT2-BCAA metabolic axis could be considered as a rational strategy for treatment of PDAC and precisive dietary intervention of BCAA has potentially translational significance.

Real-world clinical outcomes of sofosbuvir and velpatasvir treatment in HCV genotype 1- and 2-infected patients with decompensated cirrhosis: A nationwide multicenter study by the Japanese Red Cross Liver Study Group

The real-world virological efficacy and safety of interferon-free direct-acting antiviral (DAA) therapy with sofosbuvir (SOF) and velpatasvir (VEL) were assessed in hepatitis C virus (HCV) genotype 1- and 2-infected patients with decompensated cirrhosis. A total of 65 patients with HCV-related decompensated cirrhosis (Child-Pugh score of 7 points or more) who were treated with the SOF/VEL regimen were enrolled. The sustained virological response (SVR) rate and safety profile were analyzed. SVR was defined as undetectable serum HCV RNA at 12 weeks after the end of treatment (SVR12). The percentages of patients with undetectable HCV RNA at 4, 8, and 12 weeks after the start of therapy were 81.2% (95% confidence interval [CI], 69.5-89.9) (52/64), 98.4% (95% CI, 91.2-100.0) (60/61), and 98.5% (95% CI, 91.7-100.0) (64/65), respectively. The overall SVR rate was 92.3% (95% CI, 83.0-97.5) (60/65). Albumin-bilirubin (ALBI) scores decreased during and after treatment (p < 0.001), and there were significant differences between baseline and end of treatment and between baseline and SVR12. Subgroup analyses showed no significant differences in SVR rates according to patient age, sex, HCV genotype (subtype), Child-Pugh classification, modified ALBI grade, presence of ascites, presence of hepatic coma, or history of hepatocellular carcinoma. In all subpopulations, the SVR rates were higher than 80%. There were no severe adverse events associated with the treatment. The SOF/VEL regimen showed good virological efficacy and acceptable safety even in patients with HCV-related decompensated cirrhosis.

Multifaceted role of branched-chain amino acid metabolism in cancer

Metabolic reprogramming fulfils increased nutrient demands and regulates numerous oncogenic processes in tumors, leading to tumor malignancy. Branched-chain amino acids (BCAAs, i.e., valine, leucine, and isoleucine) function as nitrogen donors to generate macromolecules such as nucleotides and are indispensable for human cancer cell growth. The cell-autonomous and non-autonomous roles of altered BCAA metabolism have been implicated in cancer progression and the key proteins in the BCAA metabolic pathway serve as possible prognostic and diagnostic biomarkers in human cancers. Here we summarize how BCAA metabolic reprogramming is regulated in cancer cells and how it influences cancer progression.

Impact of Branched-Chain Amino Acid Granule Therapy in Patients with Hepatocellular Carcinoma Who Have Normal Albumin Levels and Low Branched-Chain Amino Acid to Tyrosine Ratios

Serum albumin has been reported to be a useful indicator of liver function and branched-chain amino acid (BCAA) therapy is associated with a lower incidence of hepatocellular carcinoma (HCC). We investigated the impact of BCAA granule therapy on overall survival and disease-specific survival in patients with normal albumin levels and low BCAA to tyrosine ratio (BTR)s who had treatment-naïve HCC. Overall survival and disease-specific survival was analyzed in 78 patients with HCC who were treated (n = 27) or not treated (n = 51) with BCAAs. Twenty-six patients died during the follow-up period. There were 19, 5, and 2 patients who died due to HCC, hepatic failure, and non-liver-related disease, respectively. Multivariate analysis for factors associated with overall survival indicated that BCAA therapy was independently associated with good prognosis in patients with HCC (hazard ratio [HR], 0.317; 95% confidence interval [CI], 0.123-0.813; P = 0.017). In addition, multivariate analysis using competing risks methods indicated that BCAA therapy is independently associated with reduction of disease-specific mortality (HR, 0.216; 95% CI, 0.068-0.689; P = 0.001). In conclusion, BCAA therapy improved both overall survival and disease-specific survival in HCC patients with low BTRs despite having normal albumin levels.

Branched-chain amino acids prevent hepatic fibrosis and development of hepatocellular carcinoma in a non-alcoholic steatohepatitis mouse model

Oral supplementation with branched-chain amino acids (BCAA; leucine, isoleucine, and valine) in patients with liver cirrhosis potentially suppresses the incidence of hepatocellular carcinoma (HCC) and improves event-free survival. However, the detailed mechanisms of BCAA action have not been fully elucidated. BCAA were administered to atherogenic and high-fat (Ath+HF) diet-induced nonalcoholic steatohepatitis (NASH) model mice. Liver histology, tumor incidence, and gene expression profiles were evaluated. Ath+HF diet mice developed hepatic tumors at a high frequency at 68 weeks. BCAA supplementation significantly improved hepatic steatosis, inflammation, fibrosis, and tumors in Ath+HF mice at 68 weeks. GeneChip analysis demonstrated the significant resolution of pro-fibrotic gene expression by BCAA supplementation. The anti-fibrotic effect of BCAA was confirmed further using platelet-derived growth factor C transgenic mice, which develop hepatic fibrosis and tumors. In vitro, BCAA restored the transforming growth factor (TGF)-β1-stimulated expression of pro-fibrotic genes in hepatic stellate cells (HSC). In hepatocytes, BCAA restored TGF-β1-induced apoptosis, lipogenesis, and Wnt/β-Catenin signaling, and inhibited the transformation of WB-F344 rat liver epithelial stem-like cells. BCAA repressed the promoter activity of TGFβ1R1 by inhibiting the expression of the transcription factor NFY and histone acetyltransferase p300. Interestingly, the inhibitory effect of BCAA on TGF-β1 signaling was mTORC1 activity-dependent, suggesting the presence of negative feedback regulation from mTORC1 to TGF-β1 signaling. Thus, BCAA induce an anti-fibrotic effect in HSC, prevent apoptosis in hepatocytes, and decrease the incidence of HCC; therefore, BCAA supplementation would be beneficial for patients with advanced liver fibrosis with a high risk of HCC.

Impact of the branched-chain amino acid to tyrosine ratio and branched-chain amino acid granule therapy in patients with hepatocellular carcinoma: A propensity score analysis

BACKGROUND AND AIM

It has been reported that the branched-chain amino acid (BCAA) to tyrosine ratio (BTR) is a useful indicator of liver function and BCAA therapy is associated with a decreased incidence of hepatocellular carcinoma (HCC). However, there has not been sufficient research on the relationship between BTR and the effects of BCAA therapy after initial treatment of HCC. We investigated the impact of BTR and BCAA therapy on survival in patients with HCC.

METHODS

A total of 315 patients with HCC who were treated (n = 66) or not treated (n = 249) with BCAA were enrolled; of these, 66 were selected from each group using propensity score matching. Survival from liver-related mortality was analyzed.

RESULTS

In patients who did not receive BCAA therapy (n = 249), multivariate analysis for factors associated with survival indicated that low BTR (≤ 4.4) was independently associated with poor prognosis in patients with HCC (hazard ratio, 1.880; 95% confidence interval, 1.125-3.143; P = 0.016). In addition, among patients selected by propensity score matching (n = 132), multivariate analysis indicated that BCAA therapy was independently associated with good prognosis in patients with HCC (hazard ratio, 0.524; 95% confidence interval, 0.282-0.973; P = 0.041). BTR was not significantly associated with survival.

CONCLUSIONS

Intervention involving BCAA therapy improved survival in patients with HCC versus untreated controls, regardless of BTR. In addition, low BTR was associated with poor prognosis in patients who did not receive BCAA therapy.

Hepatitis C-related liver cirrhosis - strategies for the prevention of hepatic decompensation, hepatocarcinogenesis, and mortality

Liver cirrhosis (LC) is a critical stage of chronic liver disease, including that caused by hepatitis C virus (HCV). In the absence of antiviral therapy, 67%-91% of patients with HCV-related LC patients die of liver-related causes, including hepatocellular carcinoma (HCC) and liver failure. Among the therapeutic strategies used to prevent liver-related complications in these patients is standard therapy with pegylated interferon and ribavirin, which induces a sustained virological response (SVR) in 25% of HCV genotype 1-infected patients and in 69% of patients infected with genotypes 2 and 3. SVR in patients with HCV-related LC has been associated with reduced rates of hepatic decompensation, HCC, and mortality. More recently developed direct-acting antiviral agents have shown excellent antiviral efficacy, with preliminary data demonstrating that an interferon-free regimen that includes these direct-acting antiviral agents achieved SVR in more than 50% of patients with HCV genotype 1 LC. Branched-chain amino acid supplementation, improvement of insulin resistance, and the use of β-blockers for portal hypertension may also reduce liver-related complications. Here, we review advances in antiviral and adjunctive therapies for improved outcomes in patients with HCV-associated LC.

Pharmaceutical and nutraceutical approaches for preventing liver carcinogenesis: chemoprevention of hepatocellular carcinoma using acyclic retinoid and branched-chain amino acids

The poor prognosis for patients with hepatocellular carcinoma (HCC) is associated with its high rate of recurrence in the cirrhotic liver. Therefore, more effective strategies need to be urgently developed for the chemoprevention of this malignancy. The malfunction of retinoid X receptor α, a retinoid receptor, due to phosphorylation by Ras/mitogen-activated protein kinase is closely associated with liver carcinogenesis and may be a promising target for HCC chemoprevention. Acyclic retinoid (ACR), a synthetic retinoid, can prevent HCC development by inhibiting retinoid X receptor α phosphorylation and improve the prognosis for this malignancy. Supplementation with branched-chain amino acids (BCAA), which are used to improve protein malnutrition in patients with liver cirrhosis, can also reduce the risk of HCC in obese cirrhotic patients. In experimental studies, both ACR and BCAA exert suppressive effects on HCC development and the growth of HCC cells. In particular, combined treatment with ACR and BCAA cooperatively inhibits the growth of HCC cells. Furthermore, ACR and BCAA inhibit liver tumorigenesis associated with obesity and diabetes, both of which are critical risk factors for HCC development. These findings suggest that pharmaceutical and nutraceutical approaches using ACR and BCAA may be promising strategies for preventing HCC and improving the prognosis of this malignancy.