John McPherson

Lats2/Kpm is required for embryonic development, proliferation control and genomic integrity

The Drosophila melanogaster warts/lats tumour suppressor has two mammalian counterparts LATS1/Warts‐1 and LATS2/Kpm. Here, we show that mammalian Lats orthologues exhibit distinct expression profiles according to germ cell layer origin. Lats2−/− embryos show overgrowth in restricted tissues of mesodermal lineage; however, lethality ultimately ensues on or before embryonic day 12.5 preceded by defective proliferation. Lats2−/− mouse embryonic fibroblasts (MEFs) acquire growth advantages and display a profound defect in contact inhibition of growth, yet exhibit defective cytokinesis. Lats2−/− embryos and MEFs display centrosome amplification and genomic instability. Lats2 localizes to centrosomes and overexpression of Lats2 suppresses centrosome overduplication induced in wild‐type MEFs and reverses centrosome amplification inherent in Lats2−/− MEFs. These findings indicate an essential role of Lats2 in the integrity of processes that govern centrosome duplication, maintenance of mitotic fidelity and genomic stability.

UHRF1 is a genome caretaker that facilitates the DNA damage response to γ-irradiation

BackgroundDNA double-strand breaks (DSBs) caused by ionizing radiation or by the stalling of DNA replication forks are among the most deleterious forms of DNA damage. The ability of cells to recognize and repair DSBs requires post-translational modifications to histones and other proteins that facilitate access to lesions in compacted chromatin, however our understanding of these processes remains incomplete. UHRF1 is an E3 ubiquitin ligase that has previously been linked to events that regulate chromatin remodeling and epigenetic maintenance. Previous studies have demonstrated that loss of UHRF1 increases the sensitivity of cells to DNA damage however the role of UHRF1 in this response is unclear.ResultsWe demonstrate that UHRF1 plays a critical role for facilitating the response to DSB damage caused by γ-irradiation. UHRF1-depleted cells exhibit increased sensitivity to γ-irradiation, suggesting a compromised cellular response to DSBs. UHRF1-depleted cells show impaired cell cycle arrest and an impaired accumulation of histone H2AX phosphorylation (γH2AX) in response to γ-irradiation compared to control cells. We also demonstrate that UHRF1 is required for genome integrity, in that UHRF1-depleted cells displayed an increased frequency of chromosomal aberrations compared to control cells.ConclusionsOur findings indicate a critical role for UHRF1 in maintenance of chromosome integrity and an optimal response to DSB damage.

Candidate DNA repair susceptibility genes identified by exome sequencing in high-risk pancreatic cancer

The genetic basis underlying the majority of hereditary pancreatic adenocarcinoma (PC) is unknown. Since DNA repair genes are widely implicated in gastrointestinal malignancies, including PC, we hypothesized that there are novel DNA repair PC susceptibility genes. As germline DNA repair gene mutations may lead to PC subtypes with selective therapeutic responses, we also hypothesized that there is an overall survival (OS) difference in mutation carriers versus non-carriers. We therefore interrogated the germline exomes of 109 high-risk PC cases for rare protein-truncating variants (PTVs) in 513 putative DNA repair genes. We identified PTVs in 41 novel genes among 36 kindred. Additional genetic evidence for causality was obtained for 17 genes, with FAN1, NEK1 and RHNO1 emerging as the strongest candidates. An OS difference was observed for carriers versus non-carriers of PTVs with early stage (≤IIB) disease. This adverse survival trend in carriers with early stage disease was also observed in an independent series of 130 PC cases. We identified candidate DNA repair PC susceptibility genes and suggest that carriers of a germline PTV in a DNA repair gene with early stage disease have worse survival.

Next-Generation Sequencing: A New Revolution in Molecular Diagnostics?

In 1980, Fred Sanger and Walter Gilbert were awarded the Nobel Prize in Chemistry for discovering novel ways for sequencing nucleic acids. In 2003, the human genome sequence was published, an effort that involved more than 3000 scientists from 6 countries. The work took 13 years to complete, at a cost of nearly

WaveCNV: Allele specific Copy Number Alterations in primary tumors and xenograft models from next-generation sequencing

3 billion. Only 6 years later, nucleic acid sequencing technologies have advanced to a stage in which a human genome can be sequenced within weeks at a cost of

Oxoguanine glycosylase 1 (OGG1) protects cells from DNA double-strand break damage following methylmercury (MeHg) exposure

50 000 or less. These new sequencing technologies are about a million times more efficient than standard Sanger sequencing. Now, people are talking about the

Interrogation of Functional Cell-Surface Markers Identifies CD151 Dependency in High-Grade Serous Ovarian Cancer

1000 genome, and there is an X Prize worth

Sensitivity to methylmercury toxicity is enhanced in oxoguanine glycosylase 1 knockout murine embryonic fibroblasts and is dependent on cellular proliferation capacity

10 million for sequencing 100 human genomes within 10 days at a cost of <

Abstract 118: A comprehensive profile of the genomic architecture of curable prostate cancer

10 000 per genome. International organizations are sequencing thousands of cancer genomes to find novel genetic changes, and individuals with money are paying for genomewide association studies in hopes of preventing diseases to which they are predisposed. Although the technologies for high-throughput sequencing are here and although they are being perfected in terms of accuracy and reduced costs, many questions are being raised. Some of these questions are explored below with leading scientists from academia and industry. Karl V. Voelkerding2 : Calculating the cost for sequencing a human genome needs to incorporate the level of sequencing “completeness” or “coverage” that will be required to accurately characterize both sequence and structural variation. Reagent and wet bench labor costs for sequencing a human genome should approach

Abstract 5221: Linking the molecular profile of colorectal tumors to germline genetic and environmental risk factors

5000 or less within three to five years, depending on the technology. It is difficult to price the costs for bioinformatic analysis, currently a lengthy and extensive process that varies depending on the questions being asked. New computational algorithms will definitely streamline this process. Beyond …