Yuko Kusakabe

Histone lysine methyltransferase G9a is a novel epigenetic target for the treatment of hepatocellular carcinoma

Histone H3 lysine 9 dimethylation (H3K9me2) is mainly regulated by the histone lysine methyltransferase G9a and is associated with the repression of transcription. However, both the role of G9a and the significance of H3K9me2 in hepatocellular carcinoma (HCC) cells remain unclear. In this study, we conducted loss-of-function assay of G9a using short-hairpin RNA and pharmacological interference. Knockdown of G9a reduced H3K9me2 levels and impaired both HCC cell growth and sphere formation. However, transforming growth factor β1-induced epithelial mesenchymal transition (EMT) was not suppressed by G9a knockdown. Combined analyses of chromatin immunoprecipitation followed by sequencing and RNA-sequencing led to successful identification of 96 candidate epigenetic targets of G9a. Pharmacological inhibition of G9a by BIX-01294 resulted in both cell growth inhibition and induction of apoptosis in HCC cells. Intraperitoneal administration of BIX-01294 suppressed the growth of xenograft tumors generated by implantation of HCC cells in non-obese diabetic/severe combined immunodeficient mice. Immunohistochemical analyses revealed high levels of G9a and H3K9me2 in 36 (66.7%) and 35 (64.8%) primary HCC tissues, respectively. G9a expression levels were significantly positively correlated with H3K9me2 levels in tumor tissues. In contrast, in non-tumor tissues, G9a and H3K9me2 were only observed in biliary epithelial cells and periportal hepatocytes. In conclusion, G9a inhibition impairs anchorage-dependent and -independent cell growth, but not EMT in HCC cells. Our data indicate that pharmacological interference of G9a might be a novel epigenetic approach for the treatment of HCC.

Transarterial chemoembolization as a substitute to radiofrequency ablation for treating Barcelona Clinic Liver Cancer stage 0/A hepatocellular carcinoma

Background and Aim Transarterial chemoembolization (TACE) is the standard procedure for treating Barcelona clinic liver cancer (BCLC) stage B hepatocellular carcinoma (HCC). However, it is often carried out in the treatment of BCLC stage 0/A HCC for various reasons. This study aimed to elucidate the prognosis for BCLC stage 0/A HCC patients treated with TACE or with radiofrequency ablation (RFA). Materials and Methods The prognosis of 242 BCLC stage 0/A HCC patients within Milan criteria who underwent initially TACE or RFA were retrospectively analyzed using propensity score matching analysis. Results The analyses of baseline patient characteristics revealed that the maximum tumor size and the proportion of BCLC stage A patients were significantly higher in patients treated with TACE than in those treated with RFA (P<0.001 and 0.047, respectively). After adjusting these factors using propensity score matching (1:3 matching), patients treated with TACE (n=32) and those treated with RFA (n=96) were further analyzed. The local recurrence rate was significantly higher in the TACE group than in the RFA group (P<0.001). However, the overall survival (OS) in HCC patients treated with TACE was comparable to that in HCC patients treated with RFA (1 year, 93.5 vs. 95.8%; 3 years, 75.4 vs. 85.8%; 5 years, 61.8 vs. 70.7%; P=0.196). Multivariate analyses followed by univariate analyses revealed that serum bilirubin level (P=0.032), serum albumin level (P=0.008), HBV-DNA (P=0.013), and tumor number (P=0.021) were independent predictors of OS. Conclusion TACE can substitute RFA at least in some patients with BCLC 0/A HCC.

Epigenetic dysregulation in hepatocellular carcinoma: an up-to-date review: Epigenetic dysregulation in HCC

Due to the advances made in research based on next generation sequencers, it is now possible to detect and analyze epigenetic abnormalities associated with cancer. DNA methylation, various histone modifications, chromatin remodeling, and non‐coding RNA‐associated gene silencing are considered to be transcriptional regulatory mechanisms associated with gene expression changes. The breakdown of this precise regulatory system is involved in the transition to cancer. The important role of epigenetic regulation can be observed from the high rate of genetic mutations and abnormal gene expression leading to a breakdown in epigenetic gene expression regulation seen in hepatocellular carcinoma (HCC). Based on an understanding of epigenomic abnormalities associated with pathological conditions, these findings will lead the way to diagnosis and treatment. In particular, in addition to the fact that there are few choices in terms of extant drug therapies aimed at HCC, there are limits to their antitumor effects. The clinical application of epigenetic therapeutic agents for HCC has only just begun, and future developments are expected.

Risk factors of adverse events in endoscopic retrograde cholangiopancreatography for patients aged ≥85 years: Risk factors of adverse events in ERCP

Little is known about the factors that contribute to the occurrence of adverse events in endoscopic retrograde cholangiopancreatography (ERCP) for people aged ≥85 years and safety for the super‐old. Therefore, we decided to identify these factors and to examine whether ERCP is safe in the super‐old.

Immunohistochemical analysis of IMP3 and p53 expression in endoscopic ultrasound-guided fine needle aspiration and resected specimens of pancreatic diseases

BACKGROUND Insulin-like growth factor II messenger ribonucleic acid-binding protein 3 (IMP3) is a valuable marker that distinguishes malignant from benign lesions and predicts prognosis. METHODS First, we evaluated IMP3 expression in 77 resected specimens of pancreatic ductal adenocarcinoma (PDAC), intraductal papillary mucinous neoplasm (IPMN), and chronic pancreatitis (CP). Eleven PDAC patients preoperatively underwent endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Survival analysis of IMP3 and clinicopathological factors was performed. IMP3 and p53 expression was evaluated in another 127 EUS-FNA samples of solid pancreatic masses to compare the diagnostic value of routine and immunohistochemical staining. RESULTS IMP3 expression was detected in 72.3%, 50%, 20%, and 0% of PDAC, malignant IPMN, benign IPMN, and CP, respectively. Evaluation of IMP3 expression in EUS-FNA specimens coincided with that in resected specimens in 10 of 11. IMP3 expression correlated with tumor differentiation in PDAC samples (p = .006) and with poor prognosis through univariate analysis (p = .045). Tumor differentiation and lymph node metastasis were significantly associated with poor prognosis through multivariate analysis. In EUS-FNA specimens, the sensitivity, specificity, and accuracy of cytohistological analysis were 80.8%, 100%, and 85.0%, respectively. IMP3 and p53 expression were detected in 80.8% and 44.9% of malignant and 0% and 5% of benign lesions. Combined with IMP3 immunostaining, the sensitivity, specificity and accuracy of cytohistological analysis significantly increased to 87.9%, 100%, and 90.8% (p = .016), respectively. Meanwhile, p53 staining had no impact on the results. CONCLUSIONS IMP3 immunohistochemical staining can improve the diagnostic accuracy of EUS-FNA for malignant pancreatic tumors.

Henoch-Schönlein Purpura Complicated by Hepatocellular Carcinoma

Although Henoch-Schönlein purpura (HSP) is known to be accompanied by malignancies, cases with hepatobiliary cancer are extremely rare. A 62-year-old man with palpable purpura rapidly extending to both lower legs was admitted to our hospital. He was undergoing follow-up for cirrhosis caused by chronic hepatitis B virus infection and hepatocellular carcinoma (HCC). He had renal dysfunction with hematuria and proteinuria and abdominal pain. Based on the clinical presentation and skin biopsy findings, he was diagnosed with HSP. The administration of steroids resulted in the rapid improvement of the patients symptoms and he was discharged 12 days after admission.

Successful Treatment of Hepatocellular Carcinoma Complicated by Fanconi Anemia

A 42-year-old woman with liver tumors was referred to our hospital. Her condition was complicated by Fanconi anemia, and she had undergone total laryngectomy 8 years ago. On admission, contrast-enhanced computed tomography revealed hypervascular tumors in the right hepatic lobe. Ultrasound-guided tumor biopsy revealed that the tumor comprised moderately differentiated hepatocellular carcinoma. Although the patient exhibited preserved liver function (Child-Pugh A), complete blood count revealed severe pancytopenia. Eventually, the tumor was successfully treated by transcatheter arterial embolization (TAE). Both platelet transfusion and systemic administration of antibiotics were performed. She was discharged 35 days after TAE.

Comparison of endoscopic papillary balloon dilatation and endoscopic sphincterotomy for bile duct stones

Endoscopic treatment for bile duct stones is low-invasive and currently considered as the first choice of the treatment. For the treatment of bile duct stones, papillary treatment is necessary, and the treatments used at the time are broadly classified into two types; endoscopic papillary balloon dilatation where bile duct closing part is dilated with a balloon and endoscopic sphincterotomy (EST) where bile duct closing part is incised. Both procedures have advantages and disadvantages. Golden standard is EST, however, there are patients with difficulty for EST, thus we must select the procedure based on understanding of the characteristics of the procedure, and patient backgrounds.

Prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis by pancreatic duct stenting using a loop-tipped guidewire

AIM To examine whether it is possible to prevent the occurrence of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in patients experiencing difficulties with selective biliary duct cannulation by pancreatic duct stenting using a loop-tipped guidewire. METHODS Procedure success rate, frequency of unintended insertion of the guidewire into side branches of the pancreatic duct, and incidence of procedural accidents were examined using a loop-tipped guidewire (Group A, 20 patients), and a conventional straight-type guidewire (Group B, 20 patients). RESULTS The success rate of the procedure was 100% in both groups. Unintended insertion of the guidewire into a side branch of the pancreatic duct occurred 0.056 ± 0.23 (0-1) times in Group A and 2.3 ± 1.84 (0-5) times in Group B; thus, unintended insertion of the guidewire into a side branch of the pancreatic duct was seen significantly less frequently in Group A. There were no procedural accidents in Group A, whereas pancreatitis occurred in one Group B patient; however, the difference between the two groups was not statistically significant. The serum amylase level after ERCP was 257.15 ± 136.4 (88-628) IU/L in Group A, and 552.05 ± 534.57 (101-2389) IU/L in Group B, showing a significantly lower value in Group A. Hyperamylasemia was found in two patients (10%) in Group A, and nine (45%) in Group B, showing a significantly lower value in Group A. CONCLUSION The results suggest that in patients who experience difficulties with biliary cannulation, the use of a loop-tipped guidewire for pancreatic duct stenting may assist with the prevention of post-ERCP pancreatitis, and thereby to a reduction of the risk of post-ERCP pancreatitis or hyperamylasemia.