Background: s/Aims: Hepatocellular carcinoma (HCC) is a malignant cancer with an increasing incidence worldwide. Although numerous efforts have been made to identify effective therapies for HCC, current strategies have limitations. We present a new approach for targeting L-arginine and argininosuccinate synthetase 1 (ASS1). Methods: ASS1 expression in HCC cell lines and primary hepatocytes was detected using polymerase chain reaction and western blotting. Proliferation, migration, signaling pathways, and nitric oxide production in HCC cell lines were measured using MTS, colony formation, wound healing, Western blot, and Griess assays. Results: ASS1 expression varied among the HCC cell lines, and cisplatin cytotoxicity was ASS1-dependent. L-arginine alone induced apoptosis in HCC cell lines, regardless of ASS1 expression; however, its effect was enhanced in ASS1-expressing HCC cell lines. Cisplatin cytotoxicity also increased, suggesting that L-arginine acts as a sensitizer to cisplatin in HCC cell lines. ASS1 and L-arginine produced nitric oxide and inhibited key proliferation- and survival-related signaling pathways such as PI3K/Akt and MAPK. Additionally, ASS1 and L-arginine reduced the expression of PKM1 and PKM2 in the glycolysis pathway. Conclusions Our study revealed that ASS1 and L-arginine exhibited anticancer effects in HCC and sensitized cisplatin-resistant HCC cells to chemotherapy. The combination of ASS1 and L-arginine significantly enhanced the anticancer effects, even in HCC cell lines with low or absent ASS1 expression. These findings highlight the critical roles of arginine and ASS1 in HCC and suggest that increasing arginine availability could be a promising therapeutic strategy.

Background: s/Aims: Hepatocellular carcinoma (HCC) is a malignant cancer with an increasing incidence worldwide. Although numerous efforts have been made to identify effective therapies for HCC, current strategies have limitations. We present a new approach for targeting L-arginine and argininosuccinate synthetase 1 (ASS1). Methods: ASS1 expression in HCC cell lines and primary hepatocytes was detected using polymerase chain reaction and western blotting. Proliferation, migration, signaling pathways, and nitric oxide production in HCC cell lines were measured using MTS, colony formation, wound healing, Western blot, and Griess assays. Results: ASS1 expression varied among the HCC cell lines, and cisplatin cytotoxicity was ASS1-dependent. L-arginine alone induced apoptosis in HCC cell lines, regardless of ASS1 expression; however, its effect was enhanced in ASS1-expressing HCC cell lines. Cisplatin cytotoxicity also increased, suggesting that L-arginine acts as a sensitizer to cisplatin in HCC cell lines. ASS1 and L-arginine produced nitric oxide and inhibited key proliferation- and survival-related signaling pathways such as PI3K/Akt and MAPK. Additionally, ASS1 and L-arginine reduced the expression of PKM1 and PKM2 in the glycolysis pathway. Conclusions Our study revealed that ASS1 and L-arginine exhibited anticancer effects in HCC and sensitized cisplatin-resistant HCC cells to chemotherapy. The combination of ASS1 and L-arginine significantly enhanced the anticancer effects, even in HCC cell lines with low or absent ASS1 expression. These findings highlight the critical roles of arginine and ASS1 in HCC and suggest that increasing arginine availability could be a promising therapeutic strategy.

Background: s/Aims: Hepatocellular carcinoma (HCC) is a malignant cancer with an increasing incidence worldwide. Although numerous efforts have been made to identify effective therapies for HCC, current strategies have limitations. We present a new approach for targeting L-arginine and argininosuccinate synthetase 1 (ASS1). Methods: ASS1 expression in HCC cell lines and primary hepatocytes was detected using polymerase chain reaction and western blotting. Proliferation, migration, signaling pathways, and nitric oxide production in HCC cell lines were measured using MTS, colony formation, wound healing, Western blot, and Griess assays. Results: ASS1 expression varied among the HCC cell lines, and cisplatin cytotoxicity was ASS1-dependent. L-arginine alone induced apoptosis in HCC cell lines, regardless of ASS1 expression; however, its effect was enhanced in ASS1-expressing HCC cell lines. Cisplatin cytotoxicity also increased, suggesting that L-arginine acts as a sensitizer to cisplatin in HCC cell lines. ASS1 and L-arginine produced nitric oxide and inhibited key proliferation- and survival-related signaling pathways such as PI3K/Akt and MAPK. Additionally, ASS1 and L-arginine reduced the expression of PKM1 and PKM2 in the glycolysis pathway. Conclusions Our study revealed that ASS1 and L-arginine exhibited anticancer effects in HCC and sensitized cisplatin-resistant HCC cells to chemotherapy. The combination of ASS1 and L-arginine significantly enhanced the anticancer effects, even in HCC cell lines with low or absent ASS1 expression. These findings highlight the critical roles of arginine and ASS1 in HCC and suggest that increasing arginine availability could be a promising therapeutic strategy.

Purpose: This study aimed to identify clinical and radiologic characteristics that could predict response to atezolizumab-bevacizumab combination therapy in patients with advanced hepatocellular carcinoma (HCC). Materials and Methods: This single-center retrospective study included 108 advanced HCC patients with intrahepatic lesions who were treated with atezolizumab-bevacizumab. Two radiologists independently analyzed imaging characteristics of the index tumor on pretreatment computed tomography. Predictive factors associated with progressive disease (PD) at the best response based on Response Evaluation Criteria in Solid Tumors, ver. 1.1 were evaluated using logistic regression analysis. Progression-free survival (PFS) was estimated by the Kaplan-Meier method and compared with the log-rank test. Results: Of 108 patients with a median PFS of 15 weeks, 40 (37.0%) had PD during treatment. Factors associated with PD included the presence of extrahepatic metastases (adjusted odds ratio [aOR], 4.13; 95% confidence interval [CI], 1.19 to 14.35; p=0.03), the infiltrative appearance of the tumor (aOR, 3.07; 95% CI, 1.05 to 8.93; p=0.04), and the absence of arterial-phase hyperenhancement (APHE) (aOR, 6.34; 95% CI, 2.18 to 18.47; p < 0.001). Patients with two or more of these factors had a PD of 66.7% and a median PFS of 8 weeks, indicating a significantly worse outcome compared to the patients with one or no of these factors. Conclusion In patients with advanced HCC treated with atezolizumab-bevacizumab treatment, the absence of APHE, infiltrative appearance of the intrahepatic tumor, and presence of extrahepatic metastases were associated with poor response and survival. Evaluation of early response may be necessary in patients with these factors.

Background/Aims: Tenofovir disoproxil fumarate (TDF) is known to have a lipid-lowering effect. This is in contrast to tenofovir alafenamide (TAF), which has a lipid-neutral effect. Therefore, concerns have been raised as to whether these differences affect long-term cardiovascular risk. Here, we aimed to evaluate the long-term risk of cardiovascular events in chronic hepatitis B (CHB) patients treated with TAF or TDF. Methods: We retrospectively analyzed 4,124 treatment-naïve CHB patients treated with TDF (n=3,186) or TAF (n=938) between 2012 and 2022. The primary outcome was a composite endpoint of major adverse cardiovascular events (MACE), including myocardial infarction, ischemic stroke, and hospitalization for unstable angina or heart failure. Serial changes in lipid profiles between two treatments were also explored. Results: The median age of the patients was 50.6 years, and 60.6% of the patients were male. At baseline, 486 (11.8%) and 637 (15.4%) of the patients had dyslipidemia and fatty liver, respectively. A total of 42 MACE occurred, with an annual incidence of 0.2%/100 person-years (PYs). At 1, 3, and 5 years, the cumulative risk of MACE was 0.4%, 0.8%, and 1.2% in patients treated with TDF, and 0.2%, 0.7%, and 0.7% in patients treated with TAF, respectively (p=0.538). No significant differences in the risk of MACE were observed between TDF and TAF. A multivariable analysis found that current smoker and a history of cardiovascular events were risk factors associated with an increased risk of MACE. Conclusions Patients treated with TAF had comparable risks of cardiovascular outcomes, defined as MACE, as patients treated with TDF.

Background/Aims: With the wide application of direct-acting antivirals (DAAs) for hepatitis C virus infection, the number of patients achieving a sustained virologic response (SVR) will continue to increase. However, no consensus has been achieved on exempting SVR-achieving patients from hepatocellular carcinoma (HCC) surveillance. Methods: Between 2013 and 2021, 873 Korean patients who achieved SVR following DAA treatment were analyzed. We evaluated the predictive performance of seven noninvasive scores (PAGE-B, modified PAGE-B, Toronto HCC risk index, fibrosis-4, aspartate aminotransferase-toplatelet ratio index, albumin-bilirubin, and age male albumin-bilirubin platelet [aMAP]) at baseline and after SVR. Results: The mean age of the 873 patients (39.3% males) was 59.1 years, and 224 patients (25.7%) had cirrhosis. During 3,542 person-years of follow-up, 44 patients developed HCC, with an annual incidence of 1.24/100 person-years. Male sex (adjusted hazard ratio [AHR], 2.21), cirrhosis (AHR, 7.93), and older age (AHR, 1.05) were associated with a significantly higher HCC risk in multivariate analysis. The performance of all scores at the time of SVR were numerically better than those at baseline as determined by the integrated area under the curve. Timedependent area under the curves for predicting the 3-, 5-, and 7-year risk of HCC after SVR were higher in mPAGE-B (0.778, 0.746, and 0.812, respectively) and aMAP (0.776, 0.747, and 0.790, respectively) systems than others. No patients predicted as low-risk by the aMAP or mPAGE-B systems developed HCC. Conclusions aMAP and mPAGE-B scores demonstrated the highest predictive performance for de novo HCC in DAA-treated, SVR-achieving patients. Hence, these two systems may be used to identify low-risk patients that can be exempted from HCC surveillance.

Background: s/Aims: This study aimed to compare the outcomes of liver resection (LR) and transarterial chemoembolization (TACE) in patients with multinodular hepatocellular carcinoma (HCC) within the Milan criteria who were not eligible for liver transplantation. Methods: We retrospectively analyzed 483 patients with multinodular HCC within the Milan criteria, who underwent either LR or TACE as an initial therapy between 2013 and 2022. The overall survival (OS) in the entire population and recurrence-free survival (RFS) in patients who underwent LR and TACE and achieved a complete response were analyzed. Propensity score (PS) matching analysis was also used for a fair comparison of outcomes between the two groups. Results: Among the 483 patients, 107 (22.2%) and 376 (77.8%) underwent LR and TACE, respectively. The median size of the largest tumor was 2.0 cm, and 72.3% of the patients had two HCC lesions. The median OS and RFS were significantly longer in the LR group than in the TACE group (P<0.01 for both). In the multivariate analysis, TACE (adjusted hazard ratio [aHR], 1.81 and aHR, 2.41) and large tumor size (aHR, 1.43 and aHR, 1.44) were significantly associated with worse OS and RFS, respectively. The PS-matched analysis also demonstrated that the LR group had significantly longer OS and RFS than the TACE group (PS<0.05). Conclusions In this study, LR showed better OS and RFS than TACE in patients with multinodular Barcelona Clinic Liver Cancer stage A HCC. Therefore, LR can be considered an effective treatment option for these patients.