Project description:Of the multiple anatomical sites represented in oral cancer, squamous cell carcinoma of the tongue (TSCC) shows the highest incidence among younger age group. Chewing betel leaf, areca nut & slaked lime and smoking tobacco are common practises in India which have direct clinical implication in TSCC carcinogenesis. Here, for the first time we define the landscape of genomic alterations in TSCC from the Indian diaspora which would help to identify novel therapeutic targets for clinical intervention and define the genetic basis for TSCC. We performed high throughput sequencing of fifty four tongue samples using whole exome sequencing (n=47, 23 paired normal tumor and 1 unpaired) and transcriptome sequencing (n=17, 10 tumor and 5 normal). Mutation, copy number analysis were carried out using exome sequencing data and transcriptome analysis provided expressed genes and transcript fusions in tongue cancer patients. Further, integrated analysis were performed to identify biologically relevant alterations. Our preliminary analysis revealed presence of most frequently altered mutations in TSCC which includes mutations in TP53, NOTCH1, CDKN2A, USP6, KMT2D etc, consistent with literature. We observed high frequency of CG/T(GC/A) transversions in non-CpG islands, a signature associated with tobacco exposure. Somatic copy number analysis revealed copy number gain in known hallmarks such as CCND1, MYC, ORAOV1 genes along with copy number alteration in novel genes. Significant positive correlation was observed in the genes harbouring copy number gains and showing increased expression.
Project description:Background: Whole exome sequencing (WES) has been proven to serve as a valuable basis for various applications such as variant calling and copy number variation (CNV) analyses. For those analyses the read coverage should be optimally balanced throughout protein coding regions at sufficient read depth. Unfortunately, WES is known for its uneven coverage within coding regions due to GC-rich regions or off-target enrichment. Results: In order to examine the irregularities of WES within genes, we applied Agilent SureSelectXT exome capture on human samples and sequenced these via Illumina in 2x101 paired-end mode. As we suspected the sequenced insert length to be crucial in the uneven coverage of exome captured samples, we sheared 12 genomic DNA samples to two different DNA insert size lengths, namely 130 and 170 bp. Interestingly, although mean coverages of target regions were clearly higher in samples of 130 bp insert length, the level of evenness was more pronounced in 170 bp samples. Moreover, merging overlapping paired-end reads revealed a positive effect on evenness indicating overlapping reads as another reason for the unevenness. In addition, mutation analysis on a subset of the samples was performed. In these isogenic subclones almost twofold mutations were failed in the 130 bp samples when compared to the 170 bp samples. Visual inspection of the discarded mutation sites exposed low coverages at the sites embedded in high amplitudes of coverage depth in the affected region. Conclusions: Producing longer insert reads could be a good strategy to achieve better uniform read coverage in coding regions and hereby enhancing the effective sequencing yield to provide an improved basis for further variant calling and CNV analyses.
Project description:The incidence of esophageal adenocarcinoma (EAC) has risen 600% over the last 30 years. With an extremely poor five-year survival rate of only 15%, identification of new therapeutic targets for EAC is of great importance. Here, we analyze the mutation spectra from the whole exome sequencing of 149 EAC tumors/normal pairs, 15 of which have also been subjected to whole genome sequencing. We identify a novel mutational signature in EACs defined by a high prevalence of A to C transversions at Ap*A dinucleotides. Statistical analysis of the exome data identified 26 genes that are mutated at a significant frequency. Of these 26 genes, only four (TP53, CDKN2A, SMAD4, and PIK3CA) have been previously implicated in EAC. The novel significantly mutated genes include several chromatin modifying factors and candidate contributors to EAC: SPG20, TLR4, ELMO1, and DOCK2. Notably, functional analyses of EAC-derived mutations in ELMO1 increase cellular invasion. Therefore, we suggest a new hypothesis about the potential activation of the RAC1 pathway to be a contributor to EAC tumorigenesis. The study aimed to analyze 150 primary, human esophageal adenocarcinoma samples by whole genome and whole exome sequencing (which will be deposited to dbGAP following the TCGA practice). RNA expression data was used to determine gene expression in 14 of the samples analyzed by whole genome sequencing. No normals were analyzed.
Project description:Of the multiple anatomical sites represented in oral cancer, squamous cell carcinoma of the tongue (TSCC) shows the highest incidence among younger age group. Chewing betel leaf, areca nut & slaked lime and smoking tobacco are common practises in India which have direct clinical implication in TSCC carcinogenesis. Here, for the first time we define the landscape of genomic alterations in TSCC from the Indian diaspora which would help to identify novel therapeutic targets for clinical intervention and define the genetic basis for TSCC. We performed high throughput sequencing of fifty four tongue samples using whole exome sequencing (n=47, 23 paired normal tumor and 1 unpaired) and transcriptome sequencing (n=17, 10 tumor and 5 normal). Mutation, copy number analysis were carried out using exome sequencing data and transcriptome analysis provided expressed genes and transcript fusions in tongue cancer patients. Further, integrated analysis were performed to identify biologically relevant alterations. Our preliminary analysis revealed presence of most frequently altered mutations in TSCC which includes mutations in TP53, NOTCH1, CDKN2A, USP6, KMT2D etc, consistent with literature. We observed high frequency of CG/T(GC/A) transversions in non-CpG islands, a signature associated with tobacco exposure. Somatic copy number analysis revealed copy number gain in known hallmarks such as CCND1, MYC, ORAOV1 genes along with copy number alteration in novel genes. Significant positive correlation was observed in the genes harbouring copy number gains and showing increased expression.
Project description:We collected blood samples of two non-obstructive azoospermia patients, and performed whole exome sequencing to explore the causal mutations for male infertility.
Project description:We generated meso-scale grids from mouse back skin by collecting paired whole-exome sequencing (WES) and bulk RNA sequencing (bulk RNA), retaining coordinate information to preserve spatial context across the grids. Grids were derived from untreated mice (UN, n = 4), mice treated with the cell-cycle activator TPA for twelve weeks (TO, n = 3), and mice treated with the carcinogen DMBA followed by repeated TPA until the first visible papilloma (DT, n = 3). Cumulatively, we collected 690 bulk RNA and 476 WES samples, the majority of which are paired. All DT animals developed papillomas, whereas no macroscopic skin alterations were observed in UN or TO mice.
Project description:Hypertrophic cardiomyopathy (HCM) is an extremely insidious, lethal disease caused by genetic variation and characterized by cardiac hypertrophy. It has been studied for nearly 70 years since its discovery, but its cause of the disease remains a mystery. Here, aiming to identify pathogenic genes that causes HCM, 14 patients with HCM were collected and whole exome sequencing (WES) of peripheral blood DNA was performed.