Background and Aim: Immune checkpoint inhibitors are promising agents for the treatment of hepatocellular carcinomas (HCC) refractory to conventional therapies. To enhance the efficacy of this treatment, immunological and molecular characteristics of HCC with programmed cell death ligand 1 (PD-L1) should be explored. Methods: Clinical backgrounds, PD-L1 expression, and the amount of CD8+ tumor-infiltrating mononuclear cells (TIMCs) were analyzed in 154 HCCs. The expression of 3 stem cell markers and co-inhibitory receptors on tumor cells and TIMCs, respectively, were examined by immunohistochemical analysis. Somatic mutations in the 409 cancer-associated genes and TERT promoter were determined; HCCs were classified based on the presence of gene alterations affecting the 8 oncogenic pathways. The results were validated using the dataset from the Cancer Genome Atlas. Results: The expression of PD-L1 in the HCCs was positively correlated with progressive tumor features, the presence of cytokeratin 19 (CK19), Sal-like protein 4 (SALL4), and the mutations of genes involving the phosphatidyl inositol 3-kinase (PI3K)-Akt pathway. Although CD8+ cells were densely infiltrated in PD-L1-positive tumors, these TIMCs frequently expressed multiple co-inhibitory receptors. However, a subset of PD-L1-positive tumors characterized by activating mutations of the PI3K-Akt pathway showed a low degree of TIMCs. Conversely, PD-L1-negative HCCs were associated with mutations in the β-catenin pathway and a small number of TIMCs, although the expression of co-inhibitory receptors was rare. Conclusions: PD-L1-positive HCCs frequently showed an inflamed phenotype with stem cell features; a subset of PD-L1-positive HCCs with mutations in the PI3K-Akt pathway showed a non-inflamed phenotype. In HCCs with dense infiltration of TIMCs, CD8+ cells expressed multiple co-inhibitory receptors, suggesting T cell exhaustion. On the other hand, PD-L1-negative HCCs showed mutations leading to β-catenin activation and exhibited a non-inflamed background. These characteristics should be taken into consideration for developing novel combination therapies using immune checkpoint inhibitors.

Background and Aim: Immune checkpoint inhibitors are promising agents for the treatment of hepatocellular carcinomas (HCC) refractory to conventional therapies. To enhance the efficacy of this treatment, immunological and molecular characteristics of HCC with programmed cell death ligand 1 (PD-L1) should be explored. Methods: Clinical backgrounds, PD-L1 expression, and the amount of CD8+ tumor-infiltrating mononuclear cells (TIMCs) were analyzed in 154 HCCs. The expression of 3 stem cell markers and co-inhibitory receptors on tumor cells and TIMCs, respectively, were examined by immunohistochemical analysis. Somatic mutations in the 409 cancer-associated genes and TERT promoter were determined; HCCs were classified based on the presence of gene alterations affecting the 8 oncogenic pathways. The results were validated using the dataset from the Cancer Genome Atlas. Results: The expression of PD-L1 in the HCCs was positively correlated with progressive tumor features, the presence of cytokeratin 19 (CK19), Sal-like protein 4 (SALL4), and the mutations of genes involving the phosphatidyl inositol 3-kinase (PI3K)-Akt pathway. Although CD8+ cells were densely infiltrated in PD-L1-positive tumors, these TIMCs frequently expressed multiple co-inhibitory receptors. However, a subset of PD-L1-positive tumors characterized by activating mutations of the PI3K-Akt pathway showed a low degree of TIMCs. Conversely, PD-L1-negative HCCs were associated with mutations in the β-catenin pathway and a small number of TIMCs, although the expression of co-inhibitory receptors was rare. Conclusions: PD-L1-positive HCCs frequently showed an inflamed phenotype with stem cell features; a subset of PD-L1-positive HCCs with mutations in the PI3K-Akt pathway showed a non-inflamed phenotype. In HCCs with dense infiltration of TIMCs, CD8+ cells expressed multiple co-inhibitory receptors, suggesting T cell exhaustion. On the other hand, PD-L1-negative HCCs showed mutations leading to β-catenin activation and exhibited a non-inflamed background. These characteristics should be taken into consideration for developing novel combination therapies using immune checkpoint inhibitors.

Background: Several studies suggest the role of circulating microRNAs (miRNAs) as biomarkers of hepatocellular carcinoma (HCC). However, the serum miRNA profile associated with the response to sorafenib remains to be elucidated. The aim of this study was to clarify the specific miRNAs in serum that could predict the early response of HCC to sorafenib treatment. Summary: Analyzing the sera from 16 HCC patients, we selected five miRNAs that showed differences in serum levels between patients with and without tumor responses among 179 known secretory miRNAs by using locked nucleic acid probe-based quantitative PCR. Through further analysis using a validation cohort that included 53 HCC patients who underwent sorafenib treatment and 8 healthy control subjects, we found that miR-181a-5p and miR-339-5p showed significant differences in serum levels among patients with partial response (PR), stable disease (SD), and progressive disease (PD), where PR patients showed the highest and PD the lowest levels. We also analyzed the factors associated with disease control (DC; PR or SD) 3 months after the initiation of sorafenib treatment; patients with DC showed a significantly higher level of serum miR-181a-5p than non-DC patients or healthy control subjects (p = 0.0349 and 0.0180 for DC vs. non-DC and control vs. non-DC by Tukey-Kramer test, respectively). We further conducted multivariate analysis among HCC patients with Barcelona Clinic Liver Cancer stage C using extrahepatic metastasis, serum decarboxyprothrombin, and miR-181a-5p levels as covariables; serum miR-181a-5p was the only independent factor for achieving DC (p = 0.0092, odds ratio 0.139, and 95% confidence interval 0.011-0.658). In addition, miR-181a-5p level was also the only independent factor affecting overall survival (p = 0.0194, hazard ratio 0.267, and 95% confidence interval 0.070-0.818). Key Messages: A high serum level of miR-181a-5p before treatment is associated with DC after the initiation of sorafenib.

Background: Several studies suggest the role of circulating microRNAs (miRNAs) as biomarkers of hepatocellular carcinoma (HCC). However, the serum miRNA profile associated with the response to sorafenib remains to be elucidated. The aim of this study was to clarify the specific miRNAs in serum that could predict the early response of HCC to sorafenib treatment. Summary: Analyzing the sera from 16 HCC patients, we selected five miRNAs that showed differences in serum levels between patients with and without tumor responses among 179 known secretory miRNAs by using locked nucleic acid probe-based quantitative PCR. Through further analysis using a validation cohort that included 53 HCC patients who underwent sorafenib treatment and 8 healthy control subjects, we found that miR-181a-5p and miR-339-5p showed significant differences in serum levels among patients with partial response (PR), stable disease (SD), and progressive disease (PD), where PR patients showed the highest and PD the lowest levels. We also analyzed the factors associated with disease control (DC; PR or SD) 3 months after the initiation of sorafenib treatment; patients with DC showed a significantly higher level of serum miR-181a-5p than non-DC patients or healthy control subjects (p = 0.0349 and 0.0180 for DC vs. non-DC and control vs. non-DC by Tukey-Kramer test, respectively). We further conducted multivariate analysis among HCC patients with Barcelona Clinic Liver Cancer stage C using extrahepatic metastasis, serum decarboxyprothrombin, and miR-181a-5p levels as covariables; serum miR-181a-5p was the only independent factor for achieving DC (p = 0.0092, odds ratio 0.139, and 95% confidence interval 0.011-0.658). In addition, miR-181a-5p level was also the only independent factor affecting overall survival (p = 0.0194, hazard ratio 0.267, and 95% confidence interval 0.070-0.818). Key Messages: A high serum level of miR-181a-5p before treatment is associated with DC after the initiation of sorafenib.