摘要:
Dominant negative alleles of human mismatch repair genes can be used to generate hypermutable cells and organisms. By introducing these genes into cells and transgenic animals, new cell lines and animal varieties with novel and useful properties can be prepared more efficiently than by relying on the natural rate of mutation.
摘要:
Dominant negative alleles of human mismatch repair genes can be used to generate hypermutable cells and organisms. By introducing these genes into cells and transgenic animals, new cell lines and animal varieties with novel and useful properties can be prepared more efficiently than by relying on the natural rate of mutation.
摘要:
We determined the sequence of ATRX and DAXX in 447 cancers from various sites. We found mutations most commonly in pediatric glioblastoma multiformae (GBM) (11.1%), adult GBM (6.5%), oligodendrogliomas (7.7%) and medulloblastomas (1.5%); and showed that Alternative Lengthening of Telomeres (ALT), a telomerase-independent telomere maintenance mechanism found in cancers that have not activated telomerase, perfectly correlated with somatic mutations of either gene. In contrast, neuroblastomas, and adenocarcinomas of the ovary, breast, and pancreas were negative for mutations in ATRX and DAXX. Alterations in ATRX or DAXX define a specific molecular pathway that is closely associated with an alternative telomere maintenance function in human cancers.
摘要:
The identification of mutations that are present in a small fraction of DNA templates is essential for progress in several areas of biomedical research. Though massively parallel sequencing instruments are in principle well-suited to this task, the error rates in such instruments are generally too high to allow confident identification of rare variants. We here describe an approach that can substantially increase the sensitivity of massively parallel sequencing instruments for this purpose. One example of this approach, called “Safe-SeqS” for (Safe-Sequencing System) includes (i) assignment of a unique identifier (UID) to each template molecule; (ii) amplification of each uniquely tagged template molecule to create UID-families; and (iii) redundant sequencing of the amplification products. PCR fragments with the same UID are truly mutant (“super-mutants”) if ≧95% of them contain the identical mutation. We illustrate the utility of this approach for determining the fidelity of a polymerase, the accuracy of oligonucleotides synthesized in vitro, and the prevalence of mutations in the nuclear and mitochondrial genomes of normal cells.
摘要:
Genome-wide analysis of copy number changes in breast and colorectal tumors used approaches that can reliably detect homozygous deletions and amplifications. The number of genes altered by major copy number changes—deletion of all copies or amplification of at least twelve copies per cell—averaged thirteen per tumor. These data were integrated with previous mutation analysis of the Reference Sequence genes in these same tumor types to identify genes and cellular pathways affected by both copy number changes and point alterations. Pathways enriched for genetic alterations include those controlling cell adhesion, intracellular signaling, DNA topological change, and cell cycle control. These analysis provide an integrated view of copy number and sequencing alterations on a genome-wide scale and identify genes and pathways that are useful for cancer diagnosis and therapy.
摘要:
Protein kinases are important signaling molecules involved in tumorigenesis. Mutational analysis of the human tyrosine kinase gene family (98 genes) identified somatic alterations in -20% of colorectal cancers, with the majority of mutations occurring in NTRK3, FES, GUCY2F and a previously uncharacterized tyrosine kinase gene called MCCK/MLK4. Most alterations were in conserved residues affecting key regions of the kinase domain. These data represent a paradigm for the unbiased analysis of signal transducing genes in cancer and provide useful targets for therapeutic intervention.
摘要:
There are currently few therapeutic options for patients with pancreatic cancers and new insights into the pathogenesis of this lethal disease are urgently needed. To this end, we performed a comprehensive analysis of the genes altered in 24 pancreatic tumors. First, we determined the sequences of 23,781 transcripts, representing 20,583 protein-encoding genes, in DNA from these tumors. Second, we searched for homozygous deletions and amplifications using microarrays querying ˜one million single nucleotide polymorphisms in each sample. Third, we analyzed the transcriptomes of the same samples using SAGE and next-generation sequencing-by-synthesis technologies. We found that pancreatic cancers contain an average of 63 genetic alterations, of which 49 are point mutations, 8 are homozygous deletions, and 6 are amplifications. Further analyses revealed a core set of 12 regulatory processes or pathways that were each genetically altered in 70% to 100% of the samples. The data suggest that dysregulation of this core set of pathways is responsible for the major features of pancreatic tumorigenesis.
摘要:
The present invention provides a method for detecting mutations in the PALB2 gene in pancreatic cancer patients and in individuals having a family history of pancreatic cancer. Methods are also provided for diagnosing a predisposition to pancreatic cancer, for predicting a patient's response to pancreatic cancer therapies, and for treating pancreatic cancer, based on presence of a PALB2 mutation or abberant PALB2 gene expression in a patient.
摘要:
Phosphatidylinositol 3-kinases (PI3Ks) are known to be important regulators of signaling pathways. To determine whether PI3Ks are genetically altered in cancers, we analyzed the sequences of the P13K gene family and discovered that one family member, PIK3CA, is frequently mutated in cancers of the colon and other organs. The majority of mutations clustered near two positions within the P13K helical or kinase domains. PIK3CA represents one of the most highly mutated oncogenes yet identified in human cancers and is useful as a diagnostic and therapeutic target.
摘要:
Global gene expression patterns have been characterized in normal and cancerous human cells using serial analysis of gene expression (SAGE). Cancer cell-specific, cell-type specific, and ubiquitously expressed genes have been identified. This information can be used to provide combinations of cell type- and cancer-specific gene probes, as well as methods of using these probes to identify particular cell types, screen for useful drugs, reduce cancer-specific gene expression, standardize gene expression, and restore function to a diseased cell or tissue.