Search Results - EGA European Genome-Phenome Archive

Identification and Characterization of Cancer Mutations in Japanese LungAdenocarcinoma without Sequencing of Normal Tissue Counterparts

We analyzed whole-exome sequencing data from 97 Japanese lung adenocarcinomapatients and identified several putative cancer-related genes and pathways. Particularly, we observed that cancer-related mutation patterns were significantly different between different ethnic groups. As previously reported, mutations in the EGFR gene were characteristic to Japanese, while those in the KRAS gene were more frequent in Caucasians. Furthermore, during the course of this analysis, we found that cancer-specific somatic mutations can be detected without sequencing normal tissue counterparts. 64% of the germline variants could be excluded using a total of 217 external Japanese exome datasets. We also show that a similar approach may beused for other three ethnic groups, although the discriminative power depends on the ethnic group. We demonstrate that the ATM gene and the PAPPA2 gene could be identified as cancer prognosis related genes. By bypassing the sequencing of normaltissue counterparts, this approach provides a useful means of not only reducing the time and cost of sequencing but also analyzing archive samples, for which normal tissue counterparts are not available.

Study JGAS000001

Single cell RNA seq of breast cancer stem cells

RNA sequences of breast cancer have been investigated for many patients. Recently it has been shown that there are intra-heterogeneity in tumor tissues. When the tumor cells were sequenced in bulk condition, only the major populations' mRNA will be detected. With respect to breast cancer, it has been also reported that cancer cells can sub-gropued into cancer stem cells and non-cancer stem cells. Although the mRNA expressions' difference between this two groups has been profoundly investigated, whether each group is composed by unique cell or not is yet to be elucidated. Since cancer stem cells are the thought to be the major contributor of metastasis and/or recurrence, we focused on cancer stem cells in this study. We separated cancer cells into cancer stem cells and non-cancer stem cells exploiting cancer stem cell specific surface markers. Thereafter, we sequenced mRNA of cancer stem cells in single cell resolution. From this result, we examined whether these cells can be sub-grouped or not.

Study JGAS000305

Impact of germline pathogenic variants in 27 cancer-predisposing genes on the risk of lymphoma

The application of advanced molecular technology has significantly expanded lymphoma classification, allowing risk stratification and treatment optimization. Limited evidence suggests the presence of a genetic predisposition in lymphoma, indicating the potential for better individualized clinical management based on a novel lymphoma classification. Herein, we examined the impact of germline pathogenic variants in 27 cancer-predisposing genes with lymphoma risk and explored the clinical characteristics of pathogenic variant carriers. This study included 2,066 lymphoma patients and 38,153 cancer-free controls from the Japanese population. Following quality control of sequencing data, samples from 1,982 lymphoma patients and 37,592 controls were further analyzed. Sequencing data of controls were obtained from JGAD000721. Germline pathogenic variants in some cancer-predisposing genes were associated with a high risk of lymphoma. Furthermore, germline pathogenic variants in these genes were especially associated with the higher risk of a certain subtype. These results would provide novel insights concerning monogenic form into lymphoma classification. Some lymphoma patients may benefit from surveillance and targeted treatment like other neoplasms.

Study JGAS000347

BHD-associated kidney cancer

Background Birt-Hogg-Dub? (BHD) syndrome is a hereditary kidney cancer syndrome, which predisposes patients to develop kidney cancer, cutaneous fibrofolliculomas and pulmonary cysts. The responsible gene, FLCN is a tumor suppressor for kidney cancer which plays an important role for energy homeostasis through the regulation of mitochondrial oxidative metabolism. However, how FLCN-deficiency leads to renal tumorigenesis is unclear. Results Whole-exome sequencing analysis of BHD-associated kidney cancer revealed that copy number variations (CNV) of BHD-associated kidney cancer are considerably different from those already reported in sporadic cases. Somatic mutation analysis revealed BHD-associated kidney cancer has quite few common mutations in specific genes; however, chromatin remodeling genes in total were frequently mutated in BHD-associated kidney cancer (17/29 tumors, 59%). Metabolite analysis revealed that glycolysis, pentose phosphate pathway and lipid metabolism were upregulated whereas the rate of beta oxydation and TCA cycle is decreased in BHD-associated kidney cancer compared to normal adjacent kidney. Conclusions BHD-associated kidney cancer displays a unique molecular characteristics which is totally different from that of sporadic kidney cancer, providing the mechanistic insight into tumorigenesis under FLCN deficiency as well as the foundation for the development of novel therapeutics for kidney cancer.

Study JGAS000115

Establishment of an integrated database for clinical and genomic data in cancer

In this study, to clarify the genomic varieties of MM in Asian population, we planned to investigate the genomic features in Japanese population, represented as an Asian cohort, and preformed the comprehensive genomic analysis of MM cells with newly diagnosed multiple myeloma (NDMM) by means of targeted capture sequencing (TCS) method. In our TCS assay, MM cells are subjected to the detection of following genomic abnormalities; IG rearrangements, IG associated translocations, CNAs, and somatic mutations from 340 genes related to the pathogenesis and therapeutic agent of MM.

Study JGAS000206

Defined Lifestyle and Germline Factors Predispose Asian Populations to Gastric Cancer

Gastric cancer (GC) is one of the leading causes of cancer mortality throughout the world, with the highest incidence in east-Asia. Although the somatic genetics of GC has extensively been characterized by recent advances in cancer genome sequencing, the germline and environmental effects on GC and their ethnic differences have poorly been understood. Here, we performed genomic scale trans-ethnic analysis of 531 GC cases (319 Asian and 212 non-Asians), by integrating east-Asian and public GC datasets. There is one distinct GC subclass with clear alcohol-associated mutation signature and strong Asian specificity, and almost all the cases in the subclass are attributable to alcohol intake behavior, smoking habit, and Asian-specific ALDH2 defective allele. Alcohol-related GCs have low mutation burden and a characteristic immune profile of increased B-cell infiltration into the tumor area in relation to cancer cell-intrinsic CXCL13 chemokine expression. In addition to germline variants of genes involved in BRCA pathways, we found frequent (7.4%) germline CDH1 variants among Japanese GCs. Most of them were attributed to a few recurrent SNVs shared by both Japanese and Koreans, suggesting the existence of common ancestral events and widespread distributions of these pathogenic variants among east-Asian populations. Specifically, approximately one-fifth of diffuse-type GCs were attributable to the combination of alcohol intake and defective-ALDH2 allele or to germline CDH1 variants. These results revealed uncharacterized impacts of germline variants and their interplays with lifestyles in the high incidence areas.

Study JGAS000229

Whole exome sequencing and RNA sequencing of cervical cancer

We designed this study to identify molecular markers involved in the development and prognosis of cervical adenocarcinoma. In this study, we would like to elucidate the molecular biological characteristics of cervical adenocarcinoma in relation to the carcinogenesis of other cervical cancers (squamous cell carcinoma), vaginal and vulvar cancers. In addition, some squamous cell carcinomas of the cervix develop at a young age and have a poor prognosis. Furthermore, small cell carcinoma of the cervix also progresses rapidly and has a poor prognosis, making the establishment of diagnostic and therapeutic methods an urgent task.

Study JGAS000582

Discovering novel mechanisms of taxane resistance in human breast cancer by whole-exome sequencing

Taxanes are key drugs in the treatment of breast cancer, but some breast cancers are resistant to taxanes. Obtaining extensive genomic information in a short time has recently become possible. We used whole exome-sequencing (WES) to investigate mechanisms of taxane resistance in human breast cancer. We selected six patients with breast cancer whose tumors responded well to anthracycline treatment but grew rapidly during neoadjuvant taxane-based chemotherapy. We then performed WES of these samples and identified somatic mutations of candidate genes that are thought to affect taxane resistance.

Study JGAS000370

Research of factors related to diagnosis, progression, prognosis and treatment of hepato-biliary-pancreatic malignancies

Advanced cancers with metastasis and/or recurrence are usually resistant and refractory to treatment. In our studies, whole exome sequencing analysis, comprehensive epigenetic analysis and genome-wide expression analysis were performed using cancerous and non-cancerous tissues derived from multicentric cohort study of hepatocellular carcinoma (HCC). The aim of the studies is identification of the refractoriness-related deriver genes for application to novel molecular targeted therapy and preventive medicine. The studies are intended for refractory HCC. High frequency of the tumor recurrence even after curative resection is one of the major difficulties in the treatment of HCC. According to our previous studies, not the recurrence itself, but the recurrence pattern has critical effects on prognosis of the patient with HCC. Then, we analyzed the cancerous and non-cancerous tissues of primary HCC on the point of the recurrence patterns in accordance with or without Milan criteria. The materials were obtained from thirty three patients underwent curative hepatectomy for HCC at Department of Hepato-Biliary-Pancreatic Surgery, Tokyo Medical and Dental University Hospital. Written informed consent from these patients, as well as the institutional review board approved was obtained. The determination of the refractory HCC group (16 cases) was based on the point of the recurrence patterns in accordance with Milan criteria for the recurrent tumor (solitary <5cm, or up to 3 nodules <3 cm, without major vascular invasion or distant metastasis) that has been proposed as the useful criteria of the liver transplantation for HCC. The cellular DNA was extracted from the cancerous and non-cancerous tissues of primary HCC by the phenol-chloroform method. After SNP certification using Genome-Wide Human SNP Array 6.0 (Affymetrix), whole exome sequencing was performed at the Cancer Institute of JFCR, as the support infrastructure. Exome sequencing was performed using HiSeq 2000 (Illumina), and the obtained reads were mapped to the human reference genome (hg19) using BWA software. GATK software was used for local realignment base call recalibration. Single nucleotide variants (SNVs) and indels were analyzed by MuTect and SomaticIndelDetector, as well as visual confirmation by IGV software.

Study JGAS000052

Analysis of chromosomal background of cancerous mutations using a long-read sequencer

In our previous study detecting cancerous complex SVs, we performed whole-genome sequencing of lung cancer clinical samples using PromethION. In this study, its depth and quality was substantially enriched and we conducted the phasing analysis in human lung cancer genomes. In addition, long read and short read RNA-seq was performed for transcriptome analysis.

Study JGAS000349

Germline pathogenic variant and gastric cancer risk

Germline pathogenic variants in some genes have been suggested to be associated with gastric cancer risk, although large-scale evaluations were limited. Herein, we analyzed germline variants in 27 cancer-predisposing genes in 10,426 gastric cancer patients and 38,153 controls from BioBank Japan. Following quality control of sequencing data, samples from 10,366 gastric cancer patients and 37,592 controls were further analyzed. We evaluated the association between pathogenic variants and gastric cancer risk and explored the characteristics of the pathogenic-variant carrier. Nine genes were associated with gastric cancer risk. The germline pathogenic variant carriers showed different clinical and demographic characteristics.

Study JGAS000592

Target sequencing of 27 cancer-predisposing genes and 13 renal cell carcinoma-related genes in Japanese renal cell carcinoma patients

Identifying causative genes via genetic testing is useful for the screening, prevention, and treatment of cancer. Several hereditary syndromes are known to occur in renal cell carcinoma (RCC). However, these evidences came from the European population; it remains unclear how the RCC-related genes and other cancer-predisposing genes contribute to the development RCC in the Japanese population. A case-control study of 14 RCC-related genes and 26 cancer-predisposing genes was performed using 1,563 Japanese patients with RCC and 6,016 controls. Patients were divided into two major histological subtypes of clear cell RCC (ccRCC) or non-clear cell RCC (nccRCC). Gene-based analysis of germline pathogenic variants in patients with each subtype and cancer-free subjects was performed. Following quality control, 1,532 patients with RCC and 5,996 controls were further analyzed. For ccRCC, 52 of 1,283 (4.05%) patients carried pathogenic variants mainly in the cancer-predisposing genes such as TP53 (P = 1.73 �� 10-4; OR, 5.8; 95% CI, 2.2��15.7). Approximately 80% of patients with pathogenic variants in TP53 had p.Ala189Val that was specific in East Asian population. For nccRCC, 14 of 249 (5.62%) patients carried pathogenic variants mainly in the RCC-related genes such as BAP1 (P = 6.27 �� 10-5; OR, Inf; 95% CI, 10.0��Inf), and FH (P = 6.27 �� 10-5; OR, Inf; 95% CI, 10.0��Inf). Our study showed different and population-specific contributions of risk genes between ccRCC and nccRCC in Japanese for better-personalized medicine.

Study JGAS000414

Genomic Profiling Reveals Heterogeneous Populations of Ductal Carcinoma In Situ

Whole Exome Sequencing(WES) and copy number variation(CNV) analysis were performed using breast samples collected from non-invasive breast cancer patients in order to analysis of somatic mutations related to breast tumor phenotypes.

Study JGAS000202

Whole exome sequencing of colorectal cancer

To elucidate immune status of solid tumors including gastrointenstinal cancer, we performed whole exome sequencing of colorectal cancer 7 patients.

Study JGAS000279

Sequence analysis of colorectal serrated lesions

Recent studies have shown that colorectal serrated lesions, which include sessile serrated adenomas (SSAs) and traditional serrated adenomas (TSAs), are precursors of colorectal cancer. However, the molecular mechanisms underlying the carcinogenesis, particularly in TSAs, remain largely uncharacterized. To clarify their molecular and clinicopathological characteristics, we performed mutation and methylation analyses of cancer-associated genes in 78 serrated lesions, including TSAs, SSAs and microvesicular hyperplastic polyps. Target exon sequence analysis was performed with 39 genes, including genes known to be frequently mutated in colorectal cancers and/or serrated lesions. We also used bisulfite pyrosequencing to assess the methylation status of various cancer-associated genes and marker genes of the CpG island methylator phenotype (CIMP). The prevalence of mutations in genes associated with Wnt signaling was significantly higher in TSAs than SSAs (65% vs. 28%, p < 0.01). Among those, RNF43 mutations were observed in 38% of TSAs and 17% of SSAs. In immunohistochemical studies of 39 serrated lesions, the prevalence of abnormal nuclear ?-catenin accumulation was significantly higher in TSAs (57%) than SSAs (8%) (P = 0.01). SMOC1 methylation was detected in 54% of TSAs but in no SSAs (p < 0.01). Additionally, SMOC1 methylation was more prevalent among TSAs with KRAS mutation (82%) than with BRAF mutation (38%, p = 0.03). Lesions with CIMP-high or RNF43 mutations were detected only in TSAs with BRAF mutation, suggesting two distinct carcinogenic pathways in TSAs. Mutations in genes associated with Wnt signaling play a greater role in the carcinogenesis of TSAs than SSAs.

Study JGAS000217

Genomic profiling identified ERCC2 helicase domain mutations respond to platinum-based neoadjuvant therapy in urothelial bladder cancer

Genomic profiling of tumours enables therapeutic decisions, and identifying drug-matched mutations will prolong survival and prognosis. Here, we generated a custom panel for detecting genetic alterations in 19 patients with urothelial bladder cancer. This panel targeted 71 genes associated with urological cancer. Targeted sequencing was performed on formalin-fixed paraffin-embedded tumour tissues. In this study, we revealed genome profiles and actionable mutations in patients with urothelial bladder cancer.

Study JGAS000241

Elucidation of molecular mechanism of NAFLD-HCC

We aimed to elucidate the interaction between cancer cells and immune cells in the tumor immune microenvironment of non-viral hepatocellular carcinoma.

Study JGAS000311

Homozygous inactivation of CHEK2 is linked to a familial case of multiple primary lung cancer with accompanying cancers in other organs

In clinical practice, there are a number of cancer patients with clear family histories, but not belonging to existing familial malignancies. Recent advances in genomic technologies have enhanced the possibility of identifying causative genes in such cases. Two siblings, an elder sister and a younger brother, were found to have multiple primary lung cancers at the age of 60. The former subsequently developed breast cancer, and had a history of myoma uteri. The latter had initially developed prostate cancer at the age of 59, and had a history of colon cancer. SNP genotyping revealed that approximately 10% of the genomes were homozygous in both patients. Exome sequencing revealed non-synonymous mutations in four genes in the runs of homozygosity: CHEK2, FCGRT, INPP5J, and SFI1. Evolutionary conservation of primary protein structures suggested the functional importance of the CHEK2 mutation, R474C. This mutation altered the tertiary structure of CHK2 by disrupting the salt bridge between R474 and E394. No such structural changes were observed with the other three mutated genes. Subsequent cell-based transfection analysis revealed that CHK2 R474C was unstable and scarcely activated. We concluded that CHEK2 is a causative gene in this case of familial cancer. Although homozygous inactivation of CHEK2 in mice led to cancers in multiple organs, accumulation of additional human cases is needed to establish its pathogenic role in humans.

Study JGAS000057

Development of blood-based biomarkers for precision medicine in castration-resistant prostate cancer

Cell-free DNA (cfDNA) testing is emerging as a tool for cancer precision medicine. However, little is known about the clinical significance of low-frequency variants detected in circulating cell-free tumor DNA (ctDNA) from castration-resistant prostate cancer (CRPC) patients. We conducted targeted sequencing of cfDNA and paired leukocyte DNA from CRPC patients using molecular barcodes, and ctDNA variants with a variant allele frequency ??? 0.1% were detected using an in-house pipeline.

Study JGAS000330

Mutational anysis of breast cancer stem cells

Exome sequences of breast cancer have been investigated for many patients. Recently it has been shown that there are intra-heterogeneity in tumor tissues. When the tumor cells were sequenced in bulk condition, only the major populations�� (clones��) mutations will be detected. Based on cancer stem theory, each populations�� cells are derived from each cancer stem cells, which their numbers are not so different among different clones. Here, we separated cancer cells into cancer stem cells and non-cancer stem cells exploiting cancer stem cell specific surface markers. By comping two groups�� mutation, we identified mutations, which were only detected in stem cell population. These mutations could be the mutations in cells of small size populations, and maybe the important mutations to understand the heterogeneity of tumor tissues, progression, and/or prediction for the outcome to therapies.

Study JGAS000304

Molecular Profiling and Sequential Somatic Mutation Shift in Hypermutator Tumors Harboring POLE Mutations

Defective DNA polymerase ? (POLE) proofreading leads to extensive somatic mutations that exhibits biased mutational properties; however, the characteristics of POLE-mutated tumors remain unclear. In present study, we described a molecular profile using whole exome sequencing based on the transition of somatic mutations in 10 POLE-mutated solid tumors that obtained from 2,42 Japanese patients. The bias of accumulated variations in this mutant was quantified to follow a pattern of somatic mutations, thereby classifying the sequential mutation shift into three periods. During the period prior to occurrence of the aberrant POLE, no accumulation of mutations in cancer-related genes was observed, whereas PTEN was highly mutated in conjunction with or subsequent to the event, suggesting that POLE and PTEN mutations were responsible for the development of POLE-mutated tumors. Furthermore, homologous recombination was restored after occurring PTEN mutations. Our strategy for estimation of the footprint of somatic mutations may provide new insight toward the understanding of mutation-driven tumorigenesis.

Study JGAS000130

comprehensive genetic analysis and database construction for head and neck cancer

The main purpose is to conduct comprehensive genetic analysis of head and neck malignant tumor tissue and patient-derived blood, and to construct a database for it. By analyzing these databases, we aim to clinically identify recurrence and metastasis prediction markers and establish new molecular target therapies.

Study JGAS000214

Establishment of xenogfafts and cultured cell lines from clinical samples

The purpose of the present study was to clarify the presence or absence of alterations in the molecular properties of patient-derived xenografts (PDXs) with up to eight passages in endometrial carcinomas. Alterations in the proportion of immunohistochemically positive/negative cells for PAX8, estrogen receptor, PAX2, and PTEN were observed in established PDXs of endometrioid carcinomas and carcinosarcomas, whereas proportions of cells with AE1/AE3, TP53, ARID1A PMS2, and MSH6 were maintained. Variants of cancer-associated genes in PDX compared to those in the parental tumors were examined in two cases, a frameshift deletion in BRCA1 was observed in the parental tumor tissue, and additional genomic alterations were found in the PDXs of this case. Genomic and phenotypic alterations in endometrial carcinoma PDXs relative to the parental tumors were observed and were partly associated with endometrial cancer-specific characteristics in cellular differentiation and gene mutations.

Study JGAS000585

Identification of therapeutic target molecules for prostate cancer by using next generation sequencer

Comprehensive transcriptional characterization of cancer tissues can reveal important molecular signatures associated with the disease progression. Long non-coding RNA (LncRNA) has a diversity of functions such as transcription, epigenetic and gene regulation in cancer cells including prostate cancer cells. Here, we performed directional RNA-sequence (RNA-seq) on clinical samples obtained from prostate cancer (PC) and lethal castration-resistant PC (CRPC) patients to identify novel molecular signatures including protein coding genes and non-coding RNAs induced in CRPC tissues.

Study JGAS000198

Comprehensive assay for the molecular profiling of cancer by target enrichment from formalin-fixed paraffin-embedded specimens

Tumor molecular profiling is becoming a standard of care for patients with cancer, but the optimal platform for cancer sequencing remains undetermined. We established a comprehensive assay, the Todai OncoPanel (TOP), which consists of DNA and RNA hybridization capture-based next-generation sequencing panels. A novel method for target enrichment, named the junction capture method, was developed for the RNA panel to accurately and cost-effectively detect 365 fusion genes as well as aberrantly spliced transcripts. The TOP RNA panel can also measure the expression profiles of an additional 109 genes. The TOP DNA panel was developed to detect single nucleotide variants and insertions/deletions for 464 genes, to calculate tumor mutation burden and microsatellite instability status, and to infer chromosomal copy number. Clinically relevant somatic mutations were identified in 32.2% (59/183) of patients by prospective TOP testing, signifying the clinical utility of TOP for providing personalized medicine to cancer patients.

Study JGAS000164

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