Apr
23
RNA sequencing of cancer reveals novel splicing alterations
Filed Under Publications | Leave a Comment
Breast cancer transcriptome acquires a myriad of regulation changes, and splicing is critical for the cell to “tailor-make” specific functional transcripts. Researchers at The George Washington University systematically revealed splicing signatures of the three most common types of breast tumors using RNA sequencing: TNBC, non-TNBC and HER2-positive breast cancer.
- Discovered subtype specific differentially spliced genes and splice isoforms not previously recognized in human transcriptome.
- Demonstrated that exon skip and intron retention are predominant splice events in breast cancer.
- Found that differential expression of primary transcripts and promoter switching are significantly deregulated in breast cancer compared to normal breast.
- Validated the presence of novel hybrid isoforms of critical molecules like CDK4, LARP1, ADD3, and PHLPP2.
This study provides the first comprehensive portrait of transcriptional and splicing signatures specific to breast cancer sub-types, as well as previously unknown transcripts that prompt the need for complete annotation of tissue and disease specific transcriptome.
- Eswaran J, Horvath A, Godbole S, Reddy SD, Mudvari P, Ohshiro K, Cyanam D, Nair S, Fuqua SA, Polyak K, Florea LD, Kumar R. (2013) RNA sequencing of cancer reveals novel splicing alterations. Sci Rep 3, 1689. [article]
Incoming search terms:
- www paenms seq gob mx
- tcga rsem parameter
- RNA sequencing of cancer reveals novel splicing alterations
- splicing analysis software
- rna seq breast cancer
- transcriptome breast cancer cell line
- phd position transcriptome rna-seq 2013
- splice seq
- splice junctions length statistics
- seqs of breast cancer
Jul
31
Differential Gene Expression in Tamoxifen-Resistant Breast Cancer Cells Revealed by a New Analytical Model of RNA-Seq Data
Filed Under Publications | Leave a Comment
Resistance to tamoxifen (Tam), a widely used antagonist of the estrogen receptor (ER), is a common obstacle to successful breast cancer treatment. While adjuvant therapy with Tam has been shown to significantly decrease the rate of disease recurrence and mortality, recurrent disease occurs in one third of patients treated with Tam within 5 years of therapy. A better understanding of gene expression alterations associated with Tam resistance will facilitate circumventing this problem.
Using an RNA-Seq approach and a new bioinformatics model, a team led by researchers at Penn State University compared the transcriptomes of Tam-sensitive and Tam-resistant breast cancer cells for identification of genes involved in the development of Tam resistance. They identified differential expression of 1215 mRNA and 513 small RNA transcripts clustered into ERα functions, cell cycle regulation, transcription/translation, and mitochondrial dysfunction. The extent of alterations found at multiple levels of gene regulation highlights the ability of the Tam-resistant cells to modulate global gene expression.
Alterations of small nucleolar RNA, oxidative phosphorylation, and proliferation processes in Tam-resistant cells present areas for diagnostic and therapeutic tool development for combating resistance to this anti-estrogen agent.
- Huber-Keener KJ, Liu X, Wang Z, Wang Y, Freeman W, Wu S, Planas-Silva MD, Ren X, Cheng Y, Zhang Y, Vrana K, Liu CG, Yang JM, Wu R.(2012) Differential Gene Expression in Tamoxifen-Resistant Breast Cancer Cells Revealed by a New Analytical Model of RNA-Seq Data. PLoS One 7(7), e41333. [article]
Incoming search terms:
- microRNA ppt
- breast cancer RNA-seq
- tcga rna-seq protocol
- breast cancer rna seq
- raw data that is available from published data sets (except TCGA) for exome seq/whole gen seq/rna seq of CRC
- rna-seq estrogen
- rna-seq human cancer
- rna-seq network r
- TCGA breast cancer splicing
- tcga rna-seq analysis rsem
Jun
20
The Breast Cancer Landscape
Filed Under Publications | Leave a Comment
The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups
The elucidation of breast cancer subgroups and their molecular drivers requires integrated views of the genome and transcriptome from representative numbers of patients.
A team led by researchers at the University of Cambridge, UK performed an integrated analysis of copy number and gene expression in a discovery and validation set of 997 and 995 primary breast tumours, respectively, with long-term clinical follow-up. Inherited variants (copy number variants and single nucleotide polymorphisms) and acquired somatic copy number aberrations (CNAs) were associated with expression in ~40% of genes, with the landscape dominated by cis- and trans-acting CNAs. (read more…)
- Curtis C et al. (2012) The genomic and transcriptomic architecture of 2,000 breast tumours reveals novel subgroups. Nature [Epub ahead of print]. [article]
Incoming search terms:
- ion torrent
- breast cancer landscape
- the breast cancer landscape
Feb
15
Groundbreaking Research – mRNA sequencing reveals transcriptomic landscape of breast cancer
Filed Under Publications | Leave a Comment
A team led by researchers at the George Washington University has published a study that is the first of its kind to use mRNA sequencing to look at the expression of genome, at a unprecedented resolution at the current time, in three types of breast cancer. The study titled, “Transcriptomic landscape of breast cancer through mRNA sequencing,” is published in the Feb. 14 edition of the journal, Scientific Reports, a new open access Nature journal for large volume data.
Breast cancer is a heterogeneous disease with a poorly defined genetic landscape, which poses a major challenge in diagnosis and treatment. By massively parallel mRNA sequencing, the team obtained 1.2 billion reads from 17 individual human tissues belonging to TNBC, Non-TNBC, and HER2-positive breast cancers and defined their comprehensive digital transcriptome for the first time. Surprisingly, they identified a high number of novel and unannotated transcripts, revealing the global breast cancer transcriptomic adaptations. Comparative transcriptomic analyses elucidated differentially expressed transcripts between the three breast cancer groups, identifying several new modulators of breast cancer. The study also identified common transcriptional regulatory elements, such as highly abundant primary transcripts, including osteonectin, RACK1, calnexin, calreticulin, FTL, and B2M, and “genomic hotspots” enriched in primary transcripts between the three groups. Thus, this study opens previously unexplored niches that could enable a better understanding of the disease and the development of potential intervention strategies.
(read more… )
- Eswaran J, Cyanam D, Mudvari P, Reddy SDNR, Pakala SB, Nair SS, Florea L, Fuqua SAW, Godbole S, Kumar R. (2012) Transcriptomic landscape of breast cancers through mRNA sequencing. Scientific Reports [Epub ahead of print]. [abstract]
Incoming search terms:
- RNA-seq cancer
- breast cancer rna-seq sample
- mRNA sequencing based transcriptomic analysis and cancer
- types breast cancer
Sep
2
Despite the development of molecular classifications, and prognostic and predictive gene-expression signatures, microarray-based studies have not yielded definitive answers to many of the questions that remain germane for the successful implementation of personalized medicine. Similar challenges are likely to be encountered in translating next-generation sequencing data into clinically useful information.
Needs
- The development of novel high-throughput functional assays that could interrogate the consequences of nucleic acid variations in a large number of loci and in many different genes at the same time are urgently needed in the laboratory.
- The functional significance of mutations affecting non-protein-coding genes will require the development of imaginative new functional assays.
- Training of translational and clinical researchers to understand the intricate complexity of interpreting massively parallel sequencing results and its derivatives, in conjunction with their functional consequences.
Challenges
- The current methods to determine the biological significance of novel nucleic acid variations are tedious and low throughput in the laboratory.
- The bioinformatics tools to distinguish passenger from driver mutations are still nascent.
- These tools’ sensitivity, and specificity can vary according to context, stage of tumor development, and clinical scenario.
- The functional consequences of somatic mutations in tumors may also be amplified or diminished by the genomic background of the host.
- New prognostic signatures or markers could be useful, but those currently on the horizon are unlikely to be sufficiently accurate to safely justify withholding adjuvant chemotherapy.
- No single investigator can fully comprehend and control each of the multitude of analytical steps.
- Translational medicine is a multidisciplinary endeavor; contribution from individual’s with expertise in various fields will be required.
Weigelt B, Pusztai L, Ashworth A, Reis-Filho JS. Challenges translating breast cancer gene signatures into the clinic. Nat Rev Clin Oncol [Epub ahead of print]. [abstract]
Incoming search terms:
- rna seq cancer
- cancer rna-seq
- rna seq chemotherapy
- rnaseq cancer
- rna-seq tumor
- rna-seq cancer nature
- rna-seq and cancer
- rna sequencing and caner
- rna seq in cancer
- what to do with rna-seq and cancer
Feb
9
To identify potential tumor suppressor genes, genome-wide data from exome and transcriptome sequencing were combined to search for genes with loss of heterozygosity and allele-specific expression. The analysis was conducted on the breast cancer cell line HCC1954, and a lymphoblast cell line from the same individual, HCC1954BL.
By comparing exome sequences from the two cell lines, researchers identified loss of heterozygosity events at 403 genes in HCC1954 and at one gene in HCC1954BL. The combination of exome and transcriptome sequence data also revealed 86 and 50 genes with allele specific expression events in HCC1954 and HCC1954BL, which comprise 5.4% and 2.6% of genes surveyed, respectively. Many of these genes identified by loss of heterozygosity and allele-specific expression are known or putative tumor suppressor genes, such as BRCA1, MSH3 and SETX, which participate in DNA repair pathways.
These results demonstrate that the combined application of high throughput sequencing to exome and allele-specific transcriptome analysis can reveal genes with known tumor suppressor characteristics, and a shortlist of novel candidates for the study of tumor suppressor activities.
Zhao Q, Kirkness EF, Caballero OL, Galante PA, Parmigiani RB, Edsall L, Kuan S, Ye Z, Levy S, Vasconcelos AT, Ren B, de Souza SJ, Camargo AA, Simpson AJ, Strausberg RL. (2011) Systematic detection of putative tumor suppressor genes through the combined use of exome and transcriptome sequencing. Genome Biol 11(11), R114. [article]
Incoming search terms:
- exome sequencing and rna-seq
- exome vs transcriptome
- exome rna seq
- RNA seq exome seq
- exome AND transcriptome sequencing
- exome rnaseq
- exome sequencing gene expression
- exome rna sequencing
- rna exome sequencing
- rna seq vs exome cancer
Feb
1
RNA-Seq for Discovery of Gene Fusions
Filed Under Information | 1 Comment
Until recently, chromosomal translocations and fusion genes have been an underappreciated class of mutations in solid tumors. Next-generation sequencing technologies provide an opportunity for systematic characterization of cancer cell transcriptomes, including the discovery of expressed fusion genes resulting from underlying genomic rearrangements.
Using paired-end RNA-seq and improved bioinformatic stratification, researchers at the Institute for Molecular Medicine Finland have discovered a number of novel fusion genes in breast cancer, and identified VAPB-IKZF3 as a potential fusion gene with importance for the growth and survival of breast cancer cells1.
Researchers at Genentech performed single-end RNA-Seq on human prostate adenocarcinoma samples and their corresponding normal tissues, and developed bioinformatics methods to specifically identify transcription-induced chimeras (TICs), a type of gene fusion2. Both prostate and reference samples exhibit a wide range of TIC events and some TIC events, such as MSMB-NCOA4, may play functional roles in cancer.
Deep transcriptional analysis with either single-end or paired-end RNA sequencing can effectively identify gene fusions across the genome.
1. Edgren H, Murumaegi A, Kangaspeska S, Nicorici D, Hongisto V, Kleivi K, Rye IH, Nyberg S, Wolf M, Boerresen-Dale AL, Kallioniemi O. (2011) Identification of fusion genes in breast cancer by paired-end RNA-sequencing. Genome Biol 12(1), R6. [abstract]
2. Nacu S, Yuan W, Kan Z, Bhatt D, Rivers CS, Stinson J, Peters BA, Modrusan Z, Jung K, Seshagiri S, Wu TD. (2011) Deep RNA sequencing analysis of readthrough gene fusions in human prostate adenocarcinoma and reference samples. BMC Med Genomics 4(1), 11. [abstract]
Incoming search terms:
- gene fusion rna-seq
- rna-seq gene fusion
- rna-seq fusion gene
- rna seq gene fusion
- how to identify fusion genes
- gene fusion rnaseq
- rna-seq fusion review
- fusion gene rnaseq review
- rna seq gene discovery
- rna seq application in gene discovery










