Investigation of the usefulness of a bile duct biopsy and bile cytology using a hyperspectral camera and machine learning.

To improve the efficiency of pathological diagnoses, the development of automatic pathological diagnostic systems using artificial intelligence (AI) is progressing; however, problems include the low interpretability of AI technology and the need for large amounts of data. We herein report the usefulness of a general-purpose method that combines a hyperspectral camera with machine learning. As a result of analyzing bile duct biopsy and bile cytology specimens, which are especially difficult to determine as benign or malignant, using multiple machine learning models, both were able to identify benign or malignant cells with an accuracy rate of more than 80% (93.3% for bile duct biopsy specimens and 83.2% for bile cytology specimens). This method has the potential to contribute to the diagnosis and treatment of bile duct cancer and is expected to be widely applied and utilized in general pathological diagnoses.

Microsatellite instability: A 2024 update.

Deficient mismatch repair (dMMR) results in microsatellite instability (MSI), a pronounced mutator phenotype. High-frequency MSI (MSI-H)/dMMR is gaining increasing interest as a biomarker for advanced cancer patients to determine their eligibility for immune checkpoint inhibitors (ICIs). Various methods based on next-generation sequencing (NGS) have been developed to assess the MSI status. Comprehensive genomic profiling (CGP) testing can precisely ascertain the MSI status as well as genomic alterations in a single NGS test. The MSI status can be also ascertained through the liquid biopsy-based CGP assays. MSI-H has thus been identified in various classes of tumors, resulting in a greater adoption of immunotherapy, which is hypothesized to be effective against malignancies that possess a substantial number of mutations and/or neoantigens. NGS-based studies have also characterized MSI-driven carcinogenesis, including significant rates of fusion kinases in colorectal cancers (CRCs) with MSI-H that are targets for therapeutic kinase inhibitors, particularly in MLH1-methylated CRCs with wild-type KRAS/BRAF. NTRK fusion is linked to the colorectal serrated neoplasia pathway. Recent advances in investigations of MSI-H malignancies have resulted in the development of novel diagnostic or therapeutic techniques, such as a synthetic lethal therapy that targets the Werner gene. DNA sensing in cancer cells is required for antitumor immunity induced by dMMR, opening up novel avenues and biomarkers for immunotherapy. Therefore, clinical relevance exists for analyses of MSI and MSI-H-associated genomic alterations in malignancy. In this article, we provide an update on MSI-driven carcinogenesis, with an emphasis on unique landscapes of diagnostic and immunotherapeutic strategies.

Elective Cholecystectomy After Endoscopic Gallbladder Stenting for Acute Cholecystitis: A Propensity Score Matching Analysis.

OBJECTIVE: To investigate the influence of endoscopic gallbladder stenting (EGBS) on subsequent cholecystectomy. We retrospectively compared the surgical outcomes of EGBS, followed by elective cholecystectomy with those of immediate cholecystectomy (IC). PATIENTS AND METHODS: A total of 503 patients were included in this study. Patients who underwent EGBS as initial treatment for acute cholecystitis, followed by elective cholecystectomy, were included in the EGBS group and patients who underwent IC during hospitalization were included in the IC group. Propensity score matching analysis was used to compare the surgical outcomes. In addition, the factors that increased the amount of bleeding were examined by multivariate analysis after matching. RESULTS: Fifty-seven matched pairs were obtained after propensity matching the EGBS group and the IC group. The rate of laparoscopic cholecystectomy in the EGBS versus IC groups was 91.2% versus 49.1% ( P < 0.001). The amount of bleeding was 5 mL in the EGBS versus 188 mL in the IC group ( P < 0.001). In the EGBS and IC groups, multivariate analysis of factors associated with more blood loss revealed IC (odds ratio: 4.76, 95% CI: 1.25-20.76, P = 0.022) as an independent risk factor. CONCLUSION: EGBS as the initial treatment for acute cholecystitis and subsequent elective cholecystectomy after the inflammation has disappeared can be performed in minimally invasive procedures and safely.

Increased expression of TNFRSF14 and LIGHT in biliary epithelial cells of patients with primary sclerosing cholangitis.

BACKGROUND AND AIMS: There is a lack of biliary epithelial molecular markers for primary sclerosing cholangitis (PSC). We analyzed candidates from disease susceptibility genes identified in recent genome-wide association studies (GWAS). METHODS: Expression levels of GWAS genes were analyzed in archival liver tissues of patients with PSC and controls. Immunohistochemical analysis was performed to evaluate expression levels in the biliary epithelia of PSC (N = 45) and controls (N = 12). Samples from patients with primary biliary cholangitis (PBC) were used as disease controls (N = 20). RESULTS: Hepatic expression levels of ATXN2, HHEX, PRDX5, MST1, and TNFRSF14 were significantly altered in the PSC group. We focused on the immune-related receptor, TNFRSF14. Immunohistochemistry revealed that high expression of TNFRSF14 in biliary epithelial cells was observed only in the PSC group. In addition, the expression of LIGHT, which encodes a TNFRSF14-activating ligand, was increased in PSC liver. Immunohistochemistry showed that high expression of LIGHT was more common in PSC biliary epithelia (53%) than in the PBC (15%) or control (0%) groups; moreover, it was positively associated with fibrotic progression, although it was not an independent prognostic factor. CONCLUSIONS: TNFRSF14 and LIGHT are promising candidate markers for PSC.

Post-operative mortality and recurrence patterns in pancreatic cancer according to KRAS mutation and CDKN2A, p53, and SMAD4 expression.

Alterations in KRAS, CDKN2A (p16), TP53, and SMAD4 genes have been major drivers of pancreatic carcinogenesis. The clinical course of patients with pancreatic cancer in relation to these driver alterations has not been fully characterised in large populations. We hypothesised that pancreatic carcinomas with different combinations of KRAS mutation and aberrant expression of CDKN2A, p53, and SMAD4 might show distinctive recurrence patterns and post-operative survival outcomes. To test this hypothesis, we utilised a multi-institutional cohort of 1,146 resected pancreatic carcinomas and assessed KRAS mutations by droplet digital polymerase chain reaction and CDKN2A, p53, and SMAD4 expression by immunohistochemistry. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were computed according to each molecular alteration and the number of altered genes using the Cox regression models. Multivariable competing risks regression analyses were conducted to assess the associations of the number of altered genes with specific patterns of recurrence. Loss of SMAD4 expression was associated with short DFS (multivariable HR, 1.24; 95% CI, 1.09-1.43) and OS times (multivariable HR, 1.27; 95% CI, 1.10-1.46). Compared to cases with 0-2 altered genes, cases with three and four altered genes had multivariable HRs for OS of 1.28 (95% CI, 1.09-1.51) and 1.47 (95% CI, 1.22-1.78), respectively (ptrend < 0.001). Patients with an increasing number of altered genes were more likely to have short DFS time (ptrend = 0.003) and to develop liver metastasis (ptrend = 0.006) rather than recurrence at local or other distant sites. In conclusion, loss of SMAD4 expression and an increasing number of altered genes were associated with unfavourable outcomes in pancreatic cancer patients. This study suggests that the accumulation of the four major driver alterations can confer a high metastatic potential to the liver, thereby impairing post-operative survival among patients with pancreatic cancer.

A novel self-assembling peptide hemostatic gel as rescue therapy for fistula bleeding after endoscopic ultrasound-guided hepaticogastrostomy.

The novel synthetic self-assembling peptide PuraStat has been approved for hemostasis in endoscopic procedures. Nakahara and colleagues describe their application of PuraStat for hemostasis of refractory fistula bleeding after endoscopic ultrasound-guided hepaticogastrostomy. The effective and technically easy procedure is a useful option when hemostasis cannot be achieved by other means.

Clinical Outcomes of Intraductal Papillary Mucinous Neoplasms With Dilatation of the Main Pancreatic Duct.

BACKGROUND & AIMS: Dilatation of the main pancreatic duct (MPD) has been a surgical indication for intraductal papillary mucinous neoplasms (IPMNs). Few studies have investigated long-term outcomes of IPMNs with MPD dilatation. METHODS: Among 3610 patients diagnosed with pancreatic cysts between 1994 and 2021, we identified 2829 IPMN patients, including 282 patients with MPD ≥5 mm, and examined short-term (≤6 months) and long-term risks of pancreatic carcinoma. Utilizing competing risks proportional hazards models, we estimated subdistribution hazard ratios for incidence of pancreatic carcinoma with adjustment for potential confounders. RESULTS: In analyses of short-term outcomes of the 282 patients with MPD dilatation, 72 (26%) patients were diagnosed with pancreatic carcinoma based on surgical or nonsurgical exploration. During long-term follow-up of 168 patients, we documented 24 (14%) patients diagnosed with pancreatic carcinoma (18 with IPMN-derived carcinoma and 6 with concomitant ductal adenocarcinoma). The patients with the MPD = 5-9.9 mm had cumulative incidence rates of pancreatic carcinoma diagnosis of 8.1% (95% confidence interval [CI], 4.3%-13.5%) and 10.0% (95% CI, 5.5%-15.9%) at 2 and 5 years, respectively; and the patients with the MPD ≥10 mm had the corresponding rates of 16.0% (95% CI, 3.6-36.5%) and 33.3% (95% CI, 10.3%-58.8%). The multivariable subdistribution hazard ratios were 2.78 (95% CI, 1.57-4.90) and 7.00 (95% CI, 2.58-19.0) for the MPD = 5-9.9 mm and ≥10 mm (vs <5 mm), respectively. CONCLUSIONS: IPMNs with MPD dilatation at baseline were associated with higher prevalence and incidence of pancreatic carcinoma compared with IPMNs with no MPD dilatation.

HNF1B-driven three-dimensional chromatin structure for molecular classification in pancreatic cancers.

The molecular subtypes of pancreatic cancer (PC), either classical/progenitor-like or basal/squamous-like, are currently a major topic of research because of their direct association with clinical outcomes. Some transcription factors (TFs) have been reported to be associated with these subtypes. However, the mechanisms by which these molecular signatures of PCs are established remain unknown. Epigenetic regulatory processes, supported by dynamic changes in the chromatin structure, are essential for transcriptional profiles. Previously, we reported the importance of open chromatin profiles in the biological features and transcriptional status of PCs. Here, we aimed to analyze the relationships between three-dimensional (3D) genome structures and the molecular subtypes of human PCs using Hi-C analysis. We observed a correlation of the specific elements of 3D genome modules, including compartments, topologically associating domains, and enhancer-promoter loops, with the expression of related genes. We focused on HNF1B, a TF that is implicated in the progenitor subtype. Forced expression of HNF1B in squamous-type PC organoids induced the upregulation and downregulation of genes associated with progenitor and squamous subtypes, respectively. Long-range genomic interactions induced by HNF1B were accompanied by compartment modulation and H3K27ac redistribution. We also found that these HNF1B-induced changes in subtype-related gene expression required an intrinsically disordered region, suggesting a possible involvement of phase separation in compartment modulation. Thus, mapping of 3D structural changes induced by TFs, such as HNF1B, may become a useful resource for further understanding the molecular features of PCs.

Long-term outcomes of endoscopic transpapillary gallbladder drainage using a novel spiral plastic stent in acute calculus cholecystitis.

BACKGROUND: Endoscopic transpapillary gallbladder stenting (EGBS) is considered for patients with contraindications to early surgery for acute calculus cholecystitis. However, evidence regarding the long-term outcomes of EGBS is insufficient to date. The aim of the study was to evaluate the feasibility of EGBS as a bridge to or alternative to surgery when there are contraindications. METHODS: We reviewed the cases of patients who underwent EGBS using a novel spiral-shaped plastic stent for acute calculus cholecystitis between January 2011 and December 2019. We retrospectively evaluated the long-term outcomes of EGBS using a novel spiral-shaped plastic stent. RESULTS: Forty-nine patients were included. The clinical success rate of EGBS was 97%. After EGBS, 25 patients (surgery group) underwent elective cholecystectomy and 24 patients did not (follow-up group). In the surgery group, the median period from EGBS to surgery was 93 days. There was a single late adverse event with cholecystitis recurrence. In the follow-up group, the median follow-up period was 236 days. Late adverse events were observed in eight patients, including recurrence of cholecystitis (four patients), duodenal penetration by the distal stent end (two patients), and distal stent migration (two patient). In the follow-up group, the time to recurrence of biliary obstruction was 527 days. CONCLUSIONS: EGBS with a novel spiral-shaped plastic stent is safe and effective for long-term acute calculus cholecystitis. There is a possibility of EGBS to be a bridge to surgery and a surgical alternative for acute calculus cholecystitis in patients with contraindications to early cholecystectomy.

Risk factors for liver-related mortality of patients with hepatitis C virus after sustained virologic response to direct-acting antiviral agents.

Background and Aim: The aim of this study was to identify the factors associated with liver-related and non-liver-related mortality of patients with hepatitis C virus (HCV) after sustained virologic response (SVR) to direct-acting antiviral agents (DAAs). Methods: We conducted a retrospective, single-center cohort study of HCV patients cured by DAAs. Results: A total of 330 patients with SVR to DAAs were eligible. The median follow-up period was 3.38 years (inter-quartile range: 2.03-4.58). The cumulative liver-related or non-liver-related mortality rates at 1, 3, and 5 years were 0.00 or 1.29%, 2.87 or 3.60%, and 5.10 or 9.46, respectively. Among the liver-related deaths, 9 of the 10 were from liver cancer. Among the non-liver-related deaths, the most common cause was malignancy. Through multivariate analysis using the Cox proportional hazard model, diabetes mellitus (DM, hazard ratio 13.1, 95% confidence interval 2.81-61.3) and a history of hepatocellular carcinoma (HCC, 12.8, 2.76-59.2), independently predicted liver-related death. No variables were associated with non-liver-related death. Conclusion: Our findings suggest that DM and a history of HCC are risk factors for liver-related mortality of HCV patients cured by DAAs. These results indicate that early management of HCV and HCC surveillance of diabetic patients after SVR are important to increase the chance of survival. Further studies are needed to confirm the association of DM and HCC history with survival.

Targeting the Metabolic Rewiring in Pancreatic Cancer and Its Tumor Microenvironment.

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with only a few effective therapeutic options. A characteristic feature of PDAC is its unique tumor microenvironment (TME), termed desmoplasia, which shows extensive fibrosis and extracellular matrix deposition, generating highly hypoxic and nutrient-deprived conditions within the tumor. To thrive in this harsh TME, PDAC undergoes extensive metabolic rewiring that includes the altered use of glucose and glutamine, constitutive activation of autophagy-lysosomal pathways, and nutrient acquisition from host cells in the TME. Notably, these properties support PDAC metabolism and mediate therapeutic resistance, including immune suppression. A deeper understanding of the unique metabolic properties of PDAC and its TME may aid in the development of novel therapeutic strategies against this deadly disease.

Targeting autophagy as a therapeutic strategy against pancreatic cancer.

Macroautophagy (hereafter autophagy) is a catabolic process through which cytosolic components are captured in the autophagosome and degraded in the lysosome. Autophagy plays two major roles: nutrient recycling under starvation or stress conditions and maintenance of cellular homeostasis by removing the damaged organelles or protein aggregates. In established cancer cells, autophagy-mediated nutrient recycling promotes tumor progression, whereas in normal/premalignant cells, autophagy suppresses tumor initiation by eliminating the oncogenic/harmful molecules. Pancreatic ductal adenocarcinoma (PDAC) is a deadly disease that is refractory to most currently available treatment modalities, including immune checkpoint blockade and molecular-targeted therapy. One prominent feature of PDAC is its constitutively active and elevated autophagy-lysosome function, which enables PDAC to thrive in its nutrient-scarce tumor microenvironment. In addition to metabolic support, autophagy promotes PDAC progression in a metabolism-independent manner by conferring resistance to therapeutic treatment or facilitating immune evasion. Besides to cell-autonomous autophagy in cancer cells, host autophagy (autophagy in non-cancer cells) supports PDAC progression, further highlighting autophagy as a promising therapeutic target in PDAC. Based on a growing list of compelling preclinical evidence, there are numerous ongoing clinical trials targeting the autophagy-lysosome pathway in PDAC. Given the multifaceted and context-dependent roles of autophagy in both cancer cells and normal host cells, a deeper understanding of the mechanisms underlying the tumor-promoting roles of autophagy as well as of the consequences of autophagy inhibition is necessary for the development of autophagy inhibition-based therapies against PDAC.

KRAS variant allele frequency, but not mutation positivity, associates with survival of patients with pancreatic cancer.

KRAS mutation is a major driver of pancreatic carcinogenesis and will likely be a therapeutic target. Due to lack of sensitive assays for clinical samples of pancreatic cancer with low cellularity, KRAS mutations and their prognostic association have not been fully examined in large populations. In a multi-institutional cohort of 1162 pancreatic cancer patients with formalin-fixed paraffin-embedded tumor samples, we undertook droplet digital PCR (ddPCR) for KRAS codons 12/13/61. We examined detection rates of KRAS mutations by clinicopathological parameters and survival associations of KRAS mutation status. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were computed using the Cox regression model with adjustment for potential confounders. KRAS mutations were detected in 1139 (98%) patients. The detection rate did not differ by age of tissue blocks, tumor cellularity, or receipt of neoadjuvant chemotherapy. KRAS mutations were not associated with DFS or OS (multivariable HR comparing KRAS-mutant to KRAS-wild-type tumors, 1.04 [95% CI, 0.62-1.75] and 1.05 [95% CI, 0.60-1.84], respectively). Among KRAS-mutant tumors, KRAS variant allele frequency (VAF) was inversely associated with DFS and OS with HRs per 20% VAF increase of 1.27 (95% CI, 1.13-1.42; ptrend <0.001) and 1.31 (95% CI, 1.16-1.48; ptrend <0.001), respectively. In summary, ddPCR detected KRAS mutations in clinical specimens of pancreatic cancer with high sensitivity irrespective of parameters potentially affecting mutation detections. KRAS VAF, but not mutation positivity, was associated with survival of pancreatic cancer patients.

Inhibiting SCAP/SREBP exacerbates liver injury and carcinogenesis in murine nonalcoholic steatohepatitis.

Enhanced de novo lipogenesis mediated by sterol regulatory element-binding proteins (SREBPs) is thought to be involved in nonalcoholic steatohepatitis (NASH) pathogenesis. In this study, we assessed the impact of SREBP inhibition on NASH and liver cancer development in murine models. Unexpectedly, SREBP inhibition via deletion of the SREBP cleavage-activating protein (SCAP) in the liver exacerbated liver injury, fibrosis, and carcinogenesis despite markedly reduced hepatic steatosis. These phenotypes were ameliorated by restoring SREBP function. Transcriptome and lipidome analyses revealed that SCAP/SREBP pathway inhibition altered the fatty acid (FA) composition of phosphatidylcholines due to both impaired FA synthesis and disorganized FA incorporation into phosphatidylcholine via lysophosphatidylcholine acyltransferase 3 (LPCAT3) downregulation, which led to endoplasmic reticulum (ER) stress and hepatocyte injury. Supplementation with phosphatidylcholines significantly improved liver injury and ER stress induced by SCAP deletion. The activity of the SCAP/SREBP/LPCAT3 axis was found to be inversely associated with liver fibrosis severity in human NASH. SREBP inhibition also cooperated with impaired autophagy to trigger liver injury. Thus, excessively strong and broad lipogenesis inhibition was counterproductive for NASH therapy; this will have important clinical implications in NASH treatment.

MNX1-HNF1B Axis Is Indispensable for Intraductal Papillary Mucinous Neoplasm Lineages.

BACKGROUND & AIMS: Chromatin architecture governs cell lineages by regulating the specific gene expression; however, its role in the diversity of cancer development remains unknown. Among pancreatic cancers, pancreatic ductal adenocarcinoma (PDAC) and intraductal papillary mucinous neoplasms (IPMN) with an associated invasive carcinoma (IPMNinv) arise from 2 distinct precursors, and their fundamental differences remain obscure. Here, we aimed to assess the difference of chromatin architecture regulating the transcriptional signatures or biological features in pancreatic cancers. METHODS: We established 28 human organoids from distinct subtypes of pancreatic tumors, including IPMN, IPMNinv, and PDAC. We performed exome sequencing (seq), RNA-seq, assay for transposase-accessible chromatin-seq, chromatin immunoprecipitation-seq, high-throughput chromosome conformation capture, and phenotypic analyses with short hairpin RNA or clustered regularly interspaced short palindromic repeats interference. RESULTS: Established organoids successfully reproduced the histology of primary tumors. IPMN and IPMNinv organoids harbored GNAS, RNF43, or KLF4 mutations and showed the distinct expression profiles compared with PDAC. Chromatin accessibility profiles revealed the gain of stomach-specific open regions in IPMN and the pattern of diverse gastrointestinal tissues in IPMNinv. In contrast, PDAC presented an impressive loss of accessible regions compared with normal pancreatic ducts. Transcription factor footprint analysis and functional assays identified that MNX1 and HNF1B were biologically indispensable for IPMN lineages. The upregulation of MNX1 was specifically marked in the human IPMN lineage tissues. The MNX1-HNF1B axis governed a set of genes, including MYC, SOX9, and OLFM4, which are known to be essential for gastrointestinal stem cells. High-throughput chromosome conformation capture analysis suggested the HNF1B target genes to be 3-dimensionally connected in the genome of IPMNinv. CONCLUSIONS: Our organoid analyses identified the MNX1-HNF1B axis to be biologically significant in IPMN lineages.

Updates in the Field of Submucosal Endoscopy.

Submucosal endoscopy (third-space endoscopy) can be defined as an endoscopic procedure performed in the submucosal space. This procedure is novel and has been utilized for delivery to the submucosal space in a variety of gastrointestinal diseases, such as a tumor, achalasia, gastroparesis, and subepithelial tumors. The main submucosal endoscopy includes peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, and endoscopic submucosal tunnel dissection. Submucosal endoscopy has been used as a viable alternative to surgical techniques because it is minimally invasive in the treatment and diagnosis of gastrointestinal diseases and disorders. However, there is limited evidence to prove this. This article reviews the current applications and evidence regarding submucosal endoscopy while exploring the possible future clinical applications in this field. As our understanding of these procedures improves, the future of submucosal endoscopy could be promising in the fields of diagnostic and therapeutic endoscopy.

Cell fate analysis of zone 3 hepatocytes in liver injury and tumorigenesis.

BACKGROUND & AIMS: Liver lobules are typically subdivided into 3 metabolic zones: zones 1, 2, and 3. However, the contribution of zonal differences in hepatocytes to liver regeneration, as well as to carcinogenic susceptibility, remains unclear. METHODS: We developed a new method for sustained genetic labelling of zone 3 hepatocytes and performed fate tracing to monitor these cells in multiple mouse liver tumour models. RESULTS: We first examined changes in the zonal distribution of the Wnt target gene Axin2 over time using Axin2-Cre ERT2 ;Rosa26-Lox-Stop-Lox-tdTomato mice (Axin2;tdTomato). We found that following tamoxifen administration at 3 weeks of age, approximately one-third of total hepatocytes that correspond to zone 3 were labelled in Axin2;tdTomato mice; the tdTomato+ cell distribution closely matched that of the zone 3 marker CYP2E1. Cell fate analysis revealed that zone 3 hepatocytes maintained their own lineage but rarely proliferated beyond their liver zonation during homoeostasis; this indicated that our protocol enabled persistent genetic labelling of zone 3 hepatocytes. Using this system, we found that zone 3 hepatocytes generally had high neoplastic potential, which was promoted by constitutive activation of Wnt/ß-catenin signalling in the pericentral area. However, the frequency of zone 3 hepatocyte-derived tumours varied depending on the regeneration pattern of the liver parenchyma in response to liver injury. Notably, Axin2-expressing hepatocytes undergoing chronic liver injury significantly contributed to liver regeneration and possessed high neoplastic potential. Additionally, we revealed that the metabolic phenotypes of liver tumours were acquired during tumorigenesis, irrespective of their spatial origin. CONCLUSIONS: Hepatocytes receiving Wnt/ß-catenin signalling from their microenvironment have high neoplastic potential, and Wnt/ß-catenin signalling is a potential drug target for the prevention of hepatocellular carcinoma. LAY SUMMARY: Lineage tracing revealed that zone 3 hepatocytes residing in the pericentral niche have high neoplastic potential. Under chronic liver injury, hepatocytes receiving Wnt/ß-catenin signalling broadly exist across all hepatic zones and significantly contribute to liver tumorigenesis as well as liver regeneration. Wnt/ß-catenin signalling is a potential drug target for the prevention of hepatocellular carcinoma.

FTI-277 and GGTI-289 induce apoptosis via inhibition of the Ras/ERK and Ras/mTOR pathway in head and neck carcinoma HEp-2 and HSC-3 cells.

PURPOSE: Head and neck squamous cell carcinoma (HNSCC) is a major malignancy worldwide. Ras overexpression in HNSCC is known to promote tumor cell growth; therefore, inhibition of Ras activation could lead to tumor growth suppression in HNSCC patients. Here, we investigated the effect of FTI-277, a farnesyl transferase inhibitor, and GGTI-287, a geranyltransferase 1 inhibitor, on the Ras signaling pathway in HNSCC cell lines-HEp-2 and HSC-3. METHODS: Cell viability was analyzed using the trypan blue staining exclusion assay. The apoptosis of cells was assessed by flow cytometry and caspase activation analysis. The expression levels of proteins were examined using western blot analysis. RESULTS: FTI-277 and GGTI-287 induced cell death, enhanced caspase 3 activity, and increased the number of annexin V-positive cells in HEp-2 and HSC-3 cells. FTI-277 and GGTI-287 induced apoptosis in HSC-3 cells at much lower concentrations than that in HEp-2 cells. FTI-277 and GGTI-287 decreased the concentration of phosphorylated ERK1/2 and mTOR via membrane localization of Ras and enhanced Bim expression. Furthermore, FTI-277 and GGTI-287 induced cell death in v-H-Ras-transfected NIH3T3 (NW7) cells and not in empty vector-transfected NIH3T3 (NV20) cells. CONCLUSION: FTI-277 and GGTI-287 may be useful as potential therapeutic agents for treating HNSCC patients; moreover, farnesyl transferase and geranylgeranyltransferase 1 inhibitors can be further developed as anticancer agents.

TET1 upregulation drives cancer cell growth through aberrant enhancer hydroxymethylation of HMGA2 in hepatocellular carcinoma.

Ten-eleven translocation 1 (TET1) is an essential methylcytosine dioxygenase of the DNA demethylation pathway. Despite its dysregulation being known to occur in human cancer, the role of TET1 remains poorly understood. In this study, we report that TET1 promotes cell growth in human liver cancer. The transcriptome analysis of 68 clinical liver samples revealed a subgroup of TET1-upregulated hepatocellular carcinoma (HCC), demonstrating hepatoblast-like gene expression signatures. We performed comprehensive cytosine methylation and hydroxymethylation (5-hmC) profiling and found that 5-hmC was aberrantly deposited preferentially in active enhancers. TET1 knockdown in hepatoma cell lines decreased hmC deposition with cell growth suppression. HMGA2 was highly expressed in a TET1high subgroup of HCC, associated with the hyperhydroxymethylation of its intronic region, marked as histone H3K4-monomethylated, where the H3K27-acetylated active enhancer chromatin state induced interactions with its promoter. Collectively, our findings point to a novel type of epigenetic dysregulation, methylcytosine dioxygenase TET1, which promotes cell proliferation via the ectopic enhancer of its oncogenic targets, HMGA2, in hepatoblast-like HCC.