Acute Liver Failure Due to Hypereosinophilic Syndrome Accompanied by Duodenal Perforation.

A 78-year-old woman presenting with severe acute liver failure was admitted to our hospital. On screening for the etiology of acute liver failure, it was diagnosed as being due to idiopathic hypereosinophilic syndrome (eosinophil count reported as 4766/µL; 33.8% of the white blood cells). Her medical history included marked eosinophilia, as observed six months prior to this admission. Corticosteroid therapy was initiated. During the clinical course, duodenal perforation occurred but was managed promptly by appropriate surgery. A liver biopsy, following the initiation of corticosteroid therapy, revealed degenerating hepatic cells with mild eosinophilic infiltration. With corticosteroid therapy, the liver function improved.

Colonoscopy reduces colorectal cancer mortality: A multicenter, long-term, colonoscopy-based cohort study.

BACKGROUND: There are limited colonoscopy-based cohort data concerning the effectiveness of colonoscopy in reducing colorectal cancer deaths. The aim of this study was to clarify whether colonoscopy reduces colorectal cancer mortality. METHODS: A cohort of 18,816 patients who underwent colonoscopy without a diagnosis of colorectal cancer between 2001 and 2010 at high colonoscopy procedure volume centers was selected. Patient characteristics and colonoscopy findings were assessed. The main endpoint was colorectal cancer death (all, right-sided, and left-sided cancers), and data were censored at the time of the final visit or the final colonoscopy. The standardized all colorectal, colon, and rectal cancer mortality rates were estimated with reference to those of the general Japanese population. Additional outcome was all- cause death and the standardized all-cause mortality rate was also estimated. RESULTS: The total observed person-year mortality for colorectal cancer was 67,119. Of these, 4, 3, and 1 patients died from colorectal, colon, and rectal cancers, respectively; these values were significantly lower than the number of expected deaths in the general population, estimated to be 53.1, 34.0, and 19.1, respectively. The standardized mortalities for all colorectal, colon, and rectal cancers were 0.08 (95% confidence interval (CI), 0.02-0.17), 0.09 (95% CI, 0.02-0.22), and 0.05 (95% CI, 0.0002-0.21), respectively. There were 586 all-cause deaths (3.11%) during the observation period. The standardized all-cause mortality ratios were 0.22 (95% CI, 0.206-0.23). CONCLUSIONS: The colorectal cancer mortality of patients who received colonoscopy without colorectal cancer diagnosis decreased significantly compared with that of individuals in the general population. These results were compatible even in patients with right-sided colon cancer.

Early Gastric Cancer Recurrence Following Curative Resection Presenting as Biliary Tract Dilatation, Pancreatic Duct Dilatation and Intestinal Wall Thickening.

Early gastric cancer, especially cancer confined to the mucosa (stage T1a), is known to have a high cure rate with rare recurrence. We herein report the case of a 40-year-old female who initially presented with biliary tract dilatation, pancreatic duct dilatation and intestinal wall thickening 3 years after curative resection of pT1aN0 stage gastric cancer. The intestinal resection specimen revealed tumor cells spreading through the subserosa to the submucosa sparing mucosal membrane, which made exploratory laparotomy the only approach to confirm the diagnosis. It is always important to be aware of malignancy recurrence and clinicians should not hesitate to choose exploratory laparotomy to avoid any delay in the diagnosis and treatment.

Distribution of intestinal metaplasia as a predictor of gastric cancer development.

BACKGROUND AND AIM: Helicobacter pylori, gastritis, and intestinal metaplasia (IM) are known risk factors for gastric cancer. In the present study, we conducted a cohort study to evaluate the predictive value of the distribution of IM for gastric cancer development. METHODS: We conducted a retrospective cohort study at a university hospital. From June 1998 to December 2000, we assessed histological gastritis using biopsy specimens, one from the antrum and one from the corpus, from 1450 patients, among whom 729 revisited for follow-up endoscopy. Patients were classified into three groups according to the distribution of IM at initial endoscopy. IM group A had no IM, IM group B had IM in the antrum only, and IM group C had IM in the corpus. The development of gastric cancer was assessed by endoscopic examination. RESULTS: The mean duration of follow-up was 6.7 ± 4.7 years. The cumulative incidence of gastric cancer at 5 years was 1.5% in total and 0.8%, 3.3%, and 2.7% in IM groups A, B, and C, respectively. The IM group was identified as an independent risk factor by multivariate analysis; compared with IM group A, hazard ratios were 3.6 (95% confidence interval [CI] 1.1-12.1) in IM group B and 3.8 (95% CI 1.01-14.1) in IM group C. In IM group C, the incidence of gastric cancer in patients who received eradication therapy was significantly lower than that in patients who did not receive (P = 0.021, log-rank). CONCLUSION: IM is a good predictive marker for the development of gastric cancer.

Loss of histone demethylase KDM6B enhances aggressiveness of pancreatic cancer through downregulation of C/EBPα.

Genetic mutations in pancreatic ductal adenocarcinoma (PDAC) with critical roles have been well examined. The recent discovery of alterations in genes encoding histone modifiers suggests their possible roles in the complexity of cancer development. We previously reported loss of heterozygosity of the KDM6B gene, which encodes a histone demethylase for trimethylated histone H3 lysine 27, a repressive chromatin mark, in PDAC cells. In this study, we demonstrated that loss of KDM6B enhanced aggressiveness of PDAC cells. KDM6B has been regarded as a tumor suppressor that mediates oncogenic KRAS-induced senescence. Consistently, KDM6B was highly expressed in pancreatic precancerous lesions (pancreatic intraepithelial neoplasms); then, the expression decreased as the malignant grade progressed. We found that knockdown of KDM6B in PDAC cells promoted tumor sphere formation and increased peritoneal dissemination and liver metastasis in vivo. Microarray and chromatin immunoprecipitation analysis implicated CEBPA for aggressiveness induced by KDM6B knockdown. CEBPA knockdown recapitulated the phenotypic change of PDAC cells after KDM6B knockdown, which was reversed by forced expression of C/EBPα. Moreover, similar protein expression patterns of KDM6B and C/EBPα in human PDAC emphasized their functional correlation. Notably, pharmacological inhibition of the H3K27 methylase EZH2 in PDAC cells inhibited tumor sphere formation along with the upregulation of CEBPA expression, and this effect was impaired in KDM6B knockdown cells, highlighting the role for KDM6B in the activation of CEBPA. Together, our results propose a significant role for the KDM6B-C/EBPα axis in the PDAC phenotype.

Histone demethylase KDM4C regulates sphere formation by mediating the cross talk between Wnt and Notch pathways in colonic cancer cells.

Alterations in genes coding for histone modifiers are found in human cancers, suggesting that histone modification is involved in malignant features of neoplastic cells. This study showed that a histone demethylase KDM4C is significant for colonosphere formation by mediating the cross talk between oncogenic pathways through a feed-forward mechanism. The expression of KDM4C gene was increased in spheres from colorectal cancer (CRC) cells and the knockdown (KD) of KDM4C eliminated colonosphere formation. We found that the KD of ß-catenin, an important oncogenic factor in CRC, resulted in not only decreased sphere formation but also impaired upregulation of KDM4C gene in spheres. ß-Catenin bound to the KDM4C promoter, suggesting that KDM4C is involved in the sphere-forming ability downstream of ß-catenin in CRC cells. Microarray analysis identified the JAG1 gene that codes for a notch ligand Jagged1 responsible for sphere formation as a target of KDM4C. KDM4C KD decreased the expression of JAG1 gene, and the downregulation of JAG1 gene recapitulated the impaired colonosphere formation. JAG1 is also a target of ß-catenin, and chromatin immunoprecipitation analysis showed the binding of ß-catenin and KDM4C onto the JAG1 promoter during colonosphere formation. Importantly, KDM4C KD ruined the recruitment of ß-catenin onto the JAG1 promoter independently of the H3-K9 methylation status and blunted JAG1 expression during sphere formation. These data indicate that KDM4C maintains the sphere-forming capacity in CRCs by mediating the ß-catenin-dependent transcription of JAG1 in a feed-forward manner.

Loss of 5-hydroxymethylcytosine is accompanied with malignant cellular transformation.

Dysregulated DNA methylation followed by abnormal gene expression is an epigenetic hallmark in cancer. DNA methylation is catalyzed by DNA methyltransferases, and the aberrant expression or mutations of DNA methyltransferase genes are found in human neoplasm. The enzymes for demethylating 5-methylcytosine were recently identified, and the biological significance of DNA demethylation is a current focus of scientific attention in various research fields. Ten-eleven translocation (TET) proteins have an enzymatic activity for the conversion from 5-methylcytosine to 5-hydroxymethylcytosine (5-hmC), which is an intermediate of DNA demethylation. The loss-of-function mutations of TET2 gene were reported in myeloid malignancies, suggesting that impaired TET-mediated DNA demethylation could play a crucial role in tumorigenesis. It is still unknown, however, whether DNA demethylation is involved in biological properties in solid cancers. Here, we show the loss of 5-hmC in a broad spectrum of solid tumors: for example, a significant reduction of 5-hmC was found in 72.7% of colorectal cancers (CRCs) and 75% of gastric cancers compared to background tissues. TET1 expression was decreased in half of CRCs, and a large part of them was followed by the loss of 5-hmC. These findings suggest that the amount of 5-hmC in tumors is often reduced via various mechanisms, including the downregulation of TET1. Consistently, in the in vitro experiments, the downregulation of TET1 was clearly induced by oncogene-dependent cellular transformation, and loss of 5-hmC was seen in the transformed cells. These results suggest the critical roles of aberrant DNA demethylation for oncogenic processes in solid tissues.

Altered composition of fatty acids exacerbates hepatotumorigenesis during activation of the phosphatidylinositol 3-kinase pathway.

BACKGROUND & AIMS: Some clinical findings have suggested that systemic metabolic disorders accelerate in vivo tumor progression. Deregulation of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway is implicated in both metabolic dysfunction and carcinogenesis in humans; however, it remains unknown whether the altered metabolic status caused by abnormal activation of the pathway is linked to the protumorigenic effect. METHODS: We established hepatocyte-specific Pik3ca transgenic (Tg) mice harboring N1068fs*4 mutation. RESULTS: The Tg mice exhibited hepatic steatosis and tumor development. PPARγ-dependent lipogenesis was accelerated in the Tg liver, and the abnormal profile of accumulated fatty acid (FA) composition was observed in the tumors of Tg livers. In addition, the Akt/mTOR pathway was highly activated in the tumors, and in turn, the expression of tumor suppressor genes including Pten, Xpo4, and Dlc1 decreased. Interestingly, we found that the suppression of those genes and the enhanced in vitro colony formation were induced in the immortalized hepatocytes by the treatment with oleic acid (OA), which is one of the FAs that accumulated in tumors. CONCLUSIONS: Our data suggest that the unusual FA accumulation has a possible role in promoting in vivo hepato-tumorigenesis under constitutive activation of the PI3K pathway. The Pik3ca Tg mice might help to elucidate molecular mechanisms by which metabolic dysfunction contributes to in vivo tumor progression.

Gastric cancer cell line Hs746T harbors a splice site mutation of c-Met causing juxtamembrane domain deletion.

Receptor tyrosine kinases (RTKs) are involved in oncogenesis and disease progression for many cancers. Inhibitors targeting them are vigorously developed and some of them are tested in the clinical setting. Amplifications of certain RTKs (c-Met, FGFR2 and ErbB2) have been associated with human gastric cancer progression. According to our genome-wide scans of genetic lesions in 34 gastric cancer cell lines using high-density single-nucleotide polymorphism genotyping microarrays, we confirmed that the c-met locus was amplified in four gastric cancer cell lines (Hs746T, MKN45, NUGC4 and SNU5). It was reported that somatic mutation is occasionally detected in tumor samples of a certain type of cancer with gene amplification. Previous reports showed gastric cancers harbored mutations of FGFR2 and ErbB2, but c-Met oncogenic mutation had not yet been reported. We performed mutational analysis of the cytoplasmic domains of c-Met using the genome DNA of the gastric cancer cell lines, and found that Hs746T cells had a splice site mutation of exon 14. By cDNA sequencing and Western blotting, we showed that the mutation caused juxtamembrane domain deletion. Previously, this mutation had been detected only in lung cancer specimens and this deletion resulted in the loss of Cbl E3-ligase binding causing decreased ubiquitination and delayed down-regulation. In conclusion, four gastric cancer cell lines harbored amplification of c-met locus, and among them, Hs746T had a putative oncogenic mutation with amplification. This information will be useful for screening of inhibitors targeting gastric cancer with c-Met aberration.