Published papers

© 2020, © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. The aim of this study was to develop a less invasive and accurate diagnostic system for upper urinary tract urothelial carcinoma (UTUC) based on genome-wide DNA methylation profiling. Genome-wide DNA methylation screening was performed using the Infinium HumanMethylation450 BeadChip, and DNA methylation quantification was verified using pyrosequencing. We analysed 26 samples of normal control urothelial tissue (C), an initial cohort of 62 samples (31 samples of non-cancerous urothelium [N] from UTUC patients and 31 samples of the corresponding UTUCs), a validation cohort of 82 samples (41 N and 41 UTUC samples), and 14 samples of urinary bladder urothelial carcinoma (BUC). In the initial cohort, we identified 2,448 CpG sites showing significant differences in DNA methylation levels between both C and UTUC and N and UTUC, but not showing differences between C and N. Among these CpG sites, 10 were located within CpG islands or their shores and shelves included in genomic domains where DNA methylation levels are stably controlled, allowing discrimination of UTUC even from BUC. Receiver operating characteristic curve analysis for discrimination of UTUC from N in these 10 CpG and neighbouring sites (37 diagnostic panels in total) yielded area under the curve values of 0.959–1.000, with a sensitivity and specificity of 86.6–100% and 93.5–100%, respectively. The diagnostic impact was successfully confirmed in the validation cohort. Our criteria were useful for diagnosis of UTUC, regardless of its clinicopathological features. Application of our criteria to voided urine samples will ultimately allow non-invasive DNA methylation diagnosis of UTUC.

Cell-cell adhesion determines the polarity of cells and participates in the maintenance of the cell societies called tissues. Cell-cell adhesiveness is generally reduced in human cancers. Reduced intercellular adhesiveness allows cancer cells to disobey the social order, resulting in destruction of histological structure, which is the morphological hallmark of malignant tumors. Reduced intercellular adhesiveness is also indispensable for cancer invasion and metastasis. A tumor-suppressor gene product, E-cadherin, and its undercoat proteins, catenins, which connect cadherins to actin filaments, are located at lateral borders, concentrating on adherens junctions, of epithelial cells and establish firm cell-cell adhesion. The E-cadherin cell adhesion system in cancer cells is inactivated by various mechanisms that reflect the morphological and biological characteristics of the tumor. Silencing of the E-cadherin gene by DNA hypermethylation around the promoter region occurs frequently, even in precancerous conditions. In diffuse infiltrating cancers, mutations are found in the genes for E-cadherin and alpha- and beta-catenins. At the invading front of cancers, the E-cadherin cell adhesion system is inactivated by tyrosine phosphorylation of beta-catenin; an oncogene product, c-erbB-2 protein, is found to associate directly with beta-catenin. The E-cadherin cell adhesion system cross-talks with the Wingless/Wnt signaling pathway through beta-catenin, and expression of genes, which participate in cancer morphogenesis, may be regulated in conjunction with the Wingless/Wnt signaling pathway. Dysadherin, a newly identified cancer-associated cell membrane glycoprotein, down-regulates E-cadherin and promotes cancer metastasis. In conclusion, inactivation of the E-cadherin cell adhesion system by both genetic and epigenetic mechanisms plays a significant role during multistage human carcinogenesis.

Prostate cancer mass screening using serum prostate-specific antigen (PSA) has been conducted widely in the world. However, little is known about the true prevalence of prostate cancer in the 'normal' PSA range (4.0 ng/mL or less). The aim of the present study was to elucidate the clinicopathological features of prostate cancer occurring in men with a wide range of PSA levels. The study comprised 349 male patients who underwent radical cystoprostatectomy for bladder cancer. Patients who had had treatment for known prostate cancer were excluded. Tissue specimens were reviewed microscopically. Ninety-one patients (26.1%) were found to have prostate cancer, and 68 (74.7%) of these 91 cancers were considered to be clinically significant. Both increasing patient age and PSA level were significantly correlated with an increased incidence of both all and significant prostate cancers. Sixty-five (21.9%) among 297 patients with PSA < 4.0 ng/mL had prostate cancer, and 45 (69.2%) of the 65 cancers were significant cancers. Eighteen patients had prostate cancers 0.5 mL or more in volume. Among the 18 patients, the PSA level was 4 ng/mL or more in 11, and 3 ng/mL or more in 15. Our study shows that prostate cancer is a common finding in radical cystoprostatectomy specimens excised because of bladder cancers, and a significant proportion of these cancers are clinically significant. PSA still appears to be a useful screening tool for detecting prostate cancers with significant volume. (Cancer Sci 2009; 100: 1880-1884).

© 2017 The Author(s). DBTSS (Database of Transcriptional Start Sites)/DBKERO (Database of Kashiwa Encyclopedia for human genome mutations in Regulatory regions and their Omics contexts) is the database originally initiated with the information of transcriptional start sites and their upstream transcriptional regulatory regions. In recent years, we updated the database to assist users to elucidate biological relevance of the human genome variations or somatic mutations in cancers which may affect the transcriptional regulation. In this update, we facilitate interpretations of disease associated genomic variation, using the Japanese population as a model case. We enriched the genomic variation dataset consisting of the 13,368 individuals collected for various genome-wide association studies and the reference epigenome information in the surrounding regions using a total of 455 epigenome datasets (four tissue types from 67 healthy individuals) collected for the International Human Epigenome Consortium (IHEC). The data directly obtained from the clinical samples was associated with that obtained from various model systems, such as the drug perturbation datasets using cultured cancer c

Tumor stem cells with self-renewal and multipotent capacity play critical roles in the initiation and progression of cancer. Recently, a new 3-D culture system known as organoid culture has been developed, allowing Lgr5-positive stem cells to form organoids that resemble the properties of original tissues. Here we established organoids derived from intestinal tumors of Apcmin/+ mice and normal intestinal epithelia of C57BL/6J mice and investigated the roles of microRNA (miRNA) in intestinal tumor organoids. The results of microarray analyses revealed that expression of the cluster miRNAs, miR-194 and miR-215 was markedly suppressed in intestinal tumor organoids in comparison with organoids derived from normal intestinal epithelia. Enforced expression of miR-194 resulted in inhibition of E2f3, a positive regulator of the cell cycle and growth suppression of intestinal tumor organoids. In addition, enforced expression of miR-215 suppressed the cancer stem cell signature through downregulation of intestinal stem cell markers including Lgr5. These findings indicate that the miRNA cluster including miR-194 and miR-215 plays important roles in suppressing the growth and attenuating the stemness of intestinal tumor organoids.

© Author(s) 2018. Background: Sporadic nonampullary duodenal adenocarcinoma is a rare malignant neoplasm in which poor prognosis is often associated with delayed diagnosis. Objective: A case-control study was designed to evaluate the clinical and endoscopic characteristics of patients with nonampullary duodenal epithelial tumours (NADETs). Methods: Patients with NADETs were chronologically divided into a discovery and a validation sets. Two age- and sex-matched control individuals for each case in the discovery set were randomly selected from individuals without NADET. A prediction model for the presence of NADET, constructed in the discovery set, was evaluated in the validation set. Results: In total, 368 adenomas, 81 adenocarcinomas, and 314 controls were analysed. Current smoking, Barrett oesophagus, fundic gland polyps, history of malignant disease, and absence of dyslipidaemia were independently associated with the presence of NADET. The combination of these five factors enabled significant discrimination for NADET in the bulb with a sensitivity of 0.81 in the validation set. We also showed that duodenal adenocarcinomas in the bulb had greater invasive potential than adenocar

© 2019 American Society of Clinical Oncology. Purpose Usual interstitial pneumonia (UIP) is a risk factor for lung carcinogenesis. This study was performed to characterize mutagenesis and mutational target genes underlying lung carcinogenesis in patients with UIP. Patients and Methods A cohort of 691 Japanese patients with lung adenocarcinoma (LADC), of whom 54 had UIP and 637 did not, was studied for driver oncogene aberrations. Whole-exome analysis was performed for 296 cases, including 51 with UIP, to deduce mutagenic processes and identify commonly affected genes. Logistic regression analysis was used to detect associations of gene aberrations with clinicopathological factors. Results The EGFR mutation was markedly less prevalent in patients with LADC with UIP than in those without (1.9% [one of 54] v. 49.9% [318 of 637]; P <.001), even in heavy smokers (25.3% [38 of 150] of patients with > 40 pack-years; P <.001). Mutational signature analysis indicated that UIP-positive LADCs develop through accumulation of single-nucleotide and indel mutations caused by smoking. Pulmonary surfactant system genes (PSSGs) NKX2-1/TTF1, SFTPA1, SFTPA2, SFTPB, and SFTPC were identified as targets for mutations (preferentially indels), and mutations were specifically associated with shorter overall survival of patients with UIP-positive LADC, independent of pathologic stage (hazard ratio, 4.9; 95% CI, 1.7 to 14.4; P =.0037). Conclusion LADCs with UIP develop through mutational events caused by smoking, independently of EGFR mutation. PSSGs were identified as a mutational target and as a novel prognostic factor in UIP-positive LADC. PSSG deficiency might increase the malignancy of tumor cells by increasing the tumor-promoting effects of UIP.

© 2020 International Institute of Anticancer Research. All rights reserved. Background/Aim: Uterine leiomyosarcoma (Ut- LMS) is a refractory tumor that repeatedly recurs with hematogenous metastasis, which may be due to the presence of drug-resistant tumor stem cells. Its treatment is limited to surgical procedures. We previously reported that Ut-LMS spontaneously developed in mice deficient in the proteasome component low-molecular mass polypeptide 2 (LMP2). We showed that LMP2 expression was significantly attenuated specifically in human Ut-LMS. The aim of this study was to investigate the role of LMP2 in hematogenous metastasis using xenograft models with tumor stem-like cells. Materials and Methods: We isolated tumor stem-like cells from LMP2- negative primary human Ut-LMS cells established from a human Ut-LMS tissue using the side population (SP) procedure. These cells were used to develop xenograft models with tumor stem-like cells. Results: Human Ut-LMS stem-like cells showed stronger hematogenous metastatic potential than normal Ut-LMS cells. Tumor stem-like cells also had the potential to differentiate into vascular endothelial cells through VEGF-A signaling. Conclusion: These results reflect frequent hematogenous metastasis by human Ut-LMS in clinical settings, and may lead to the development of treatments that inhibit hematogenous metastasis in Ut-LMS.

© 2021, The Author(s). Purpose: The present study was conducted to clarify the clinicopathological impacts of DNA methylation alterations on pancreatic ductal adenocarcinoma (PDAC). Methods: Genome-wide DNA methylation screening was performed using the Infinium HumanMethylation450 BeadChip, and DNA methylation quantification was verified using pyrosequencing. We analyzed fresh-frozen tissues from an initial cohort (17 samples of normal control pancreatic tissue [C] from 17 patients without PDAC, and 34 samples of non-cancerous pancreatic tissue [N] and 82 samples of cancerous tissue [T] both obtained from 82 PDAC patients) and formalin-fixed paraffin-embedded T samples from 34 patients in a validation cohort. Results: The DNA methylation profiles of N samples tended to differ from those of C samples, and 91,907 probes showed significant differences in DNA methylation levels between C and T samples. Epigenetic clustering of T samples was significantly correlated with a larger tumor diameter and early recurrence (ER), defined as relapse within 6 months after surgery. Three marker CpG sites, applicable to formalin-fixed paraffin-embedded surgically resected materials regardless of their tumor cell content, were identified for prediction of ER. The sensitivity and specificity for detection of patients belonging to the ER group using a panel combining these three marker CpG sites, including a CpG site in the CDK14 gene, were 81.8% and 71.7% and 88.9% and 70.4% in the initial and validation cohorts, respectively. Conclusion: These findings indicate that DNA methylation alterations may have a clinicopathological impact on PDAC. Application of our criteria will ultimately allow prediction of ER after surgery to improve the outcome of PDAC patients.

Background and study aims  Recent advances in endoscopic equipment and diagnostic techniques have improved the detection of dysplasia in the inflamed mucosa of patients with ulcerative colitis (UC). However, it remains difficult to endoscopically identify flat-type dysplasia which has been formerly recognized as invisible dysplasia. Patients and methods  In this retrospective, single-center study, we endoscopically identified 10 cases of flat-type-predominant dysplasia by targeted biopsy among 38 intramucosal dysplasia lesions from patients with UC who underwent surgical or endoscopic resection from 2007 to 2017. Their endoscopic and histological features were examined, including color changes, intramucosal vascular density/size, and vascular endothelial growth factor (VEGF) expression. Results  All flat-type-predominant dysplasias were endoscopically recognized as demarcated red-colored areas and histologically diagnosed as low- (LGDs) or high-grade dysplasias (HGDs). Immunohistochemical examination using resected specimens revealed that flat-type dysplasia was characterized by significantly increased CD34-positive vascular density (LGDs, 1.7-fold, P < 0.01; HGDs, 2.2-fold, P  < 0.01) and size (LGDs, 1.03-fold, P  < 0.01; HGDs, 1.11-fold, P  < 0.01) in the mucosa, compared to adjacent non-neoplastic areas. Increased numbers of vessels were observed at the base of the mucosa in LGDs, whereas HGDs contained increased/enlarged vessels throughout the mucosa. Moreover, VEGF expression was elevated in all dysplastic epithelia. Conclusions  Demarcated red-colored areas, histologically characterized by an increased vascular density/size in the mucosa, are an endoscopic sign of formerly invisible flat-type dysplasia in patients with UC and should be considered for targeted biopsy. Prospective studies focusing on the mucosal color change for their early detection would be desirable in the future.