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.

Objective: Keratin 19 (K19) expression is a potential predictor of poor prognosis in patients with hepatocellular carcinoma (HCC). To clarify the feature of K19-proficient HCC, we traced epigenetic footprints in cultured cells and clinical materials. Patients and Methods: In vitro, KRT19 promoter methylation was analyzed and 5-aza-2’-deoxycytidine with trichostatin A (TSA) treatment was performed. Among 564 surgically resected HCCs, the clinicopathological relevance of K19-proficent HCCs was performed in comparison with hepatocytic (HepPar-1 and arginase-1), epithelial-mesenchymal transition (E-cadherin and vimentin), biliary differentiation-associated (K7 and NOTCH-1) markers, and epigenetic markers (KRT19 promoter/long interspersed nucleotide element-1 [LINE-1] methylation status). Results: KRT19 promoter methylation was clearly associated with K19 deficiency and 5-aza-2’-deoxycytidine with TSA treatment-stimulated K19 re-expression, implicating DNA methylation as a potential epigenetic process for K19 expression. After excluding HCCs with recurrence, TNM stage as IIIB or greater, preoperative therapy, transplantation, and combined hepatocellular cholangiocarcinoma, we assessed 125 of 564 HCC cases. In this cohort, K19 expression was found in 29 HCCs (23.2%) and corresponded with poor survival following surgery (p = 0.025) and extrahepatic recurrence-free survival (p = 0.017). Compared with K19-deficient HCCs, lower KRT19 promoter methylation level was observed in K19-proficient HCCs (p < 0.0001). Conversely, HCC with genome-wide LINE-1 hypermethylation was frequently observed in K19-proficient HCCs (p = 0.0079). Additionally, K19 proficiency was associated with K7 proficiency (p = 0.043), and reduced E-cadherin and HepPar-1 expression (p = 0.043 and p < 0.0001, respectively). Conclusions: K19-proficient HCC exhibited poor prognosis owing to extrahepatic recurrence, with molecular signatures differing from those in conventional cancer stem cells, providing novel insights of the heterogeneity underlying tumor development.

Objective: Keratin 19 (K19) expression is a potential predictor of poor prognosis in patients with hepatocellular carcinoma (HCC). To clarify the feature of K19-proficient HCC, we traced epigenetic footprints in cultured cells and clinical materials. Patients and Methods: In vitro, KRT19 promoter methylation was analyzed and 5-aza-2’-deoxycytidine with trichostatin A (TSA) treatment was performed. Among 564 surgically resected HCCs, the clinicopathological relevance of K19-proficent HCCs was performed in comparison with hepatocytic (HepPar-1 and arginase-1), epithelial-mesenchymal transition (E-cadherin and vimentin), biliary differentiation-associated (K7 and NOTCH-1) markers, and epigenetic markers (KRT19 promoter/long interspersed nucleotide element-1 [LINE-1] methylation status). Results: KRT19 promoter methylation was clearly associated with K19 deficiency and 5-aza-2’-deoxycytidine with TSA treatment-stimulated K19 re-expression, implicating DNA methylation as a potential epigenetic process for K19 expression. After excluding HCCs with recurrence, TNM stage as IIIB or greater, preoperative therapy, transplantation, and combined hepatocellular cholangiocarcinoma, we assessed 125 of 564 HCC cases. In this cohort, K19 expression was found in 29 HCCs (23.2%) and corresponded with poor survival following surgery (p = 0.025) and extrahepatic recurrence-free survival (p = 0.017). Compared with K19-deficient HCCs, lower KRT19 promoter methylation level was observed in K19-proficient HCCs (p < 0.0001). Conversely, HCC with genome-wide LINE-1 hypermethylation was frequently observed in K19-proficient HCCs (p = 0.0079). Additionally, K19 proficiency was associated with K7 proficiency (p = 0.043), and reduced E-cadherin and HepPar-1 expression (p = 0.043 and p < 0.0001, respectively). Conclusions: K19-proficient HCC exhibited poor prognosis owing to extrahepatic recurrence, with molecular signatures differing from those in conventional cancer stem cells, providing novel insights of the heterogeneity underlying tumor development.

Background: Although Gankyrin is overexpressed in many malignancies, the role of Gankyrin for tumorigenesis and chemoresistance remains to be elucidated in sporadic colorectal cancer (CRC). Aims: We investigate whether Gankyrin affects Adenomatous polyposis coli (Apc) inactivation-induced tumorigenesis and therapeutic response to anti-angiogenic agents. Methods: Epithelial cell-specific APC and/or Gankyrin-deficient mice were used. The patients with metastatic CRC (n = 53) who were enrolled in this study underwent resection of primary cancer followed by systemic chemotherapy containing bevacizumab. We determined whether gene expression in CRC tissues before chemotherapy is associated with radiological responses. Results: Deletion of Gankyrin in epithelial cell reduced the expression of c-Myc, a critical mediator of the APC signaling pathway, and interleukin-6. Gankyrin deficiency decreased the expression of Bmi1, a downstream molecule of c-Myc, and the activity of V-Akt murine thymoma viral oncogene homolog and extracellular signal-regulated protein kinase, leading to reduced Apc inactivation-induced tumorigenesis. Of 53 patients, 38 (72%) had increased Gankyrin expression in tumor cells. The enhanced Gankyrin expression in tumor cells was associated with unfavorable progression-free survival (log-rank test p = 0.026). Conclusion: Gankyrin in epithelial cell contributes to the development of sporadic CRC and the expression could serve as a biomarker to predict therapeutic response in patients with metastatic CRC.

Background: Although Gankyrin is overexpressed in many malignancies, the role of Gankyrin for tumorigenesis and chemoresistance remains to be elucidated in sporadic colorectal cancer (CRC). Aims: We investigate whether Gankyrin affects Adenomatous polyposis coli (Apc) inactivation-induced tumorigenesis and therapeutic response to anti-angiogenic agents. Methods: Epithelial cell-specific APC and/or Gankyrin-deficient mice were used. The patients with metastatic CRC (n = 53) who were enrolled in this study underwent resection of primary cancer followed by systemic chemotherapy containing bevacizumab. We determined whether gene expression in CRC tissues before chemotherapy is associated with radiological responses. Results: Deletion of Gankyrin in epithelial cell reduced the expression of c-Myc, a critical mediator of the APC signaling pathway, and interleukin-6. Gankyrin deficiency decreased the expression of Bmi1, a downstream molecule of c-Myc, and the activity of V-Akt murine thymoma viral oncogene homolog and extracellular signal-regulated protein kinase, leading to reduced Apc inactivation-induced tumorigenesis. Of 53 patients, 38 (72%) had increased Gankyrin expression in tumor cells. The enhanced Gankyrin expression in tumor cells was associated with unfavorable progression-free survival (log-rank test p = 0.026). Conclusion: Gankyrin in epithelial cell contributes to the development of sporadic CRC and the expression could serve as a biomarker to predict therapeutic response in patients with metastatic CRC.

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.

Objective: MicroRNA-372 (miR-372) is reportedly shown to be an oncogene in human testicular germ cell tumors and gastric cancers, but its expression in colorectal cancer (CRC) is not yet determined. This study investigated the clinical significance of miR-372 expression in CRC. Methods: qRT-PCR was used to evaluate miR-372 in 144 CRC patients, and large tumor suppressor 2 (LATS2) expression was also examined as the likely target gene of miR-372. In vitroassays were performed to evaluate the biological function of miR-372. Results: Multivariate analysis indicated that high miR-372 expression was an independent prognostic factor (p = 0.006). High miR-372 expression was associated with synchronous liver metastasis (p = 0.035). We found an inverse relationship between miR-372 and LATS2 by qRT-PCR (p = 0.007) and immunohistochemistry (p = 0.042) using CRC tissue samples. Furthermore, pre-miR-372 led to a decrease in the LATS2 protein and an increase in proliferative activity of LoVo cells. We also found a significant association between low LATS2 expression and liver metastasis (p = 0.042). Conclusions: This study suggested that miR-372 was a novel independent prognostic factor in CRC. Our data suggest that LATS2 may serve as one of the target genes of miR-372 in clinical CRC tissues.

Objective: MicroRNA-372 (miR-372) is reportedly shown to be an oncogene in human testicular germ cell tumors and gastric cancers, but its expression in colorectal cancer (CRC) is not yet determined. This study investigated the clinical significance of miR-372 expression in CRC. Methods: qRT-PCR was used to evaluate miR-372 in 144 CRC patients, and large tumor suppressor 2 (LATS2) expression was also examined as the likely target gene of miR-372. In vitroassays were performed to evaluate the biological function of miR-372. Results: Multivariate analysis indicated that high miR-372 expression was an independent prognostic factor (p = 0.006). High miR-372 expression was associated with synchronous liver metastasis (p = 0.035). We found an inverse relationship between miR-372 and LATS2 by qRT-PCR (p = 0.007) and immunohistochemistry (p = 0.042) using CRC tissue samples. Furthermore, pre-miR-372 led to a decrease in the LATS2 protein and an increase in proliferative activity of LoVo cells. We also found a significant association between low LATS2 expression and liver metastasis (p = 0.042). Conclusions: This study suggested that miR-372 was a novel independent prognostic factor in CRC. Our data suggest that LATS2 may serve as one of the target genes of miR-372 in clinical CRC tissues.