Undiagnosed RASopathies in infertile men.

RASopathies are syndromes caused by congenital defects in the Ras/mitogen-activated protein kinase (MAPK) pathway genes, with a population prevalence of 1 in 1,000. Patients are typically identified in childhood based on diverse characteristic features, including cryptorchidism (CR) in >50% of affected men. As CR predisposes to spermatogenic failure (SPGF; total sperm count per ejaculate 0-39 million), we hypothesized that men seeking infertility management include cases with undiagnosed RASopathies.

Detailed longitudinal sampling of glioma stem cells in situ reveals Chr7 gain and Chr10 loss as repeated events in primary tumor formation and recurrence.

Intratumoral heterogeneity at the genetic, epigenetic, transcriptomic, and morphologic levels is a commonly observed phenomenon in many aggressive cancer types. Clonal evolution during tumor formation and in response to therapeutic intervention can be predicted utilizing reverse engineering approaches on detailed genomic snapshots of heterogeneous patient tumor samples. In this study, we developed an extensive dataset for a GBM case via the generation of polyclonal and monoclonal glioma stem cell lines from initial diagnosis, and from multiple sections of distant tumor locations of the deceased patient's brain following tumor recurrence.

A Core Regulatory Circuit in Glioblastoma Stem Cells Links MAPK Activation to a Transcriptional Program of Neural Stem Cell Identity.

Glioblastoma, the most common primary malignant brain tumor, harbors a small population of tumor initiating cells (glioblastoma stem cells) that have many properties similar to neural stem cells. To investigate common regulatory networks in both neural and glioblastoma stem cells, we subjected both cell types to in-vitro differentiation conditions and measured global gene-expression changes using gene expression microarrays. Analysis of enriched transcription factor DNA-binding sites in the promoters of differentially expressed genes was used to reconstruct regulatory networks involved in differentiation.

Identification of molecular pathways facilitating glioma cell invasion in situ.

Gliomas are mostly incurable secondary to their diffuse infiltrative nature. Thus, specific therapeutic targeting of invasive glioma cells is an attractive concept. As cells exit the tumor mass and infiltrate brain parenchyma, they closely interact with a changing micro-environmental landscape that sustains tumor cell invasion.

Micro-environment causes reversible changes in DNA methylation and mRNA expression profiles in patient-derived glioma stem cells.

In vitro and in vivo models are widely used in cancer research. Characterizing the similarities and differences between a patient's tumor and corresponding in vitro and in vivo models is important for understanding the potential clinical relevance of experimental data generated with these models. Towards this aim, we analyzed the genomic aberrations, DNA methylation and transcriptome profiles of five parental tumors and their matched in vitro isolated glioma stem cell (GSC) lines and xenografts generated from these same GSCs using high-resolution platforms.

Histone demethylase Jumonji D3 (JMJD3) as a tumor suppressor by regulating p53 protein nuclear stabilization.

Histone methylation regulates normal stem cell fate decisions through a coordinated interplay between histone methyltransferases and demethylases at lineage specific genes. Malignant transformation is associated with aberrant accumulation of repressive histone modifications, such as polycomb mediated histone 3 lysine 27 (H3K27me3) resulting in a histone methylation mediated block to differentiation. The relevance, however, of histone demethylases in cancer remains less clear.

Effect of brain- and tumor-derived connective tissue growth factor on glioma invasion.

Background: Tumor cell invasion is the principal cause of treatment failure and death among patients with malignant gliomas. Connective tissue growth factor (CTGF) has been previously implicated in cancer metastasis and invasion in various tumors. We explored the mechanism of CTGF-mediated glioma cell infiltration and examined potential therapeutic targets.

Wip1 directly dephosphorylates gamma-H2AX and attenuates the DNA damage response.

The integrity of DNA is constantly challenged throughout the life of a cell by both endogenous and exogenous stresses. A well-organized rapid damage response and proficient DNA repair, therefore, become critically important for maintaining genomic stability and cell survival. When DNA is damaged, the DNA damage response (DDR) can be initiated by alterations in chromosomal structure and histone modifications, such as the phosphorylation of the histone H2AX (the phosphorylated form is referred to as gamma-H2AX).

Chromosomal protein HMGN1 enhances the heat shock-induced remodeling of Hsp70 chromatin.

The nucleosome-binding protein HMGN1 affects the structure and function of chromatin; however, its role in regulating specific gene expression in living cells is not fully understood. Here we use embryonic fibroblasts from Hmgn1(+/+) and Hmgn1(-/-) mice to examine the effect of HMGN1 on the heat shock-induced transcriptional activation of Hsp70, a well characterized gene known to undergo a rapid chromatin re-structuring during transcriptional activation. We find that loss of HMGN1 decreases the levels of Hsp70 transcripts at the early stages of heat shock.

Chromosomal protein HMGN1 modulates the phosphorylation of serine 1 in histone H2A.

Here we demonstrate that HMGN1, a nuclear protein that binds specifically to nucleosomes, modulates the level of histone H2A phosphorylation. In Hmgn1-/- cells, loss of HMGN1 elevates the steady-state levels of H2AS1ph throughout the cell cycle. In vitro, HMGN1 reduces the rate of Rsk2- and Msk1-mediated phosphorylation of nucleosomal, but not free, histone H2A.

Chemical inhibition of Wip1 phosphatase contributes to suppression of tumorigenesis.

Wip1 is an amplified oncogene whose deletion causes a tumor resistant phenotype in mice. These observations provide justification for a search for Wip1 chemical inhibitors as potential anticancer drugs. Here we report a group of Wip1 inhibitors with anticancer properties both in vitro and in vivo.

The autoimmune suppressor Gadd45alpha inhibits the T cell alternative p38 activation pathway.

The p38 MAP kinase (MAPK) is phosphorylated and activated by upstream MAPK kinases. T cells have an alternative pathway in which T cell receptor-activated tyrosine kinase Zap70 phosphorylates p38 on Tyr323. Mice lacking Gadd45alpha, a small p38-binding molecule, develop a lupus-like autoimmune disease.

Gadd45a regulates matrix metalloproteinases by suppressing DeltaNp63alpha and beta-catenin via p38 MAP kinase and APC complex activation.

The p53-regulated growth arrest and DNA damage-inducible gene product Gadd45a has been recently identified as a key factor protecting the epidermis against ultraviolet radiation (UVR)-induced skin tumors by activating p53 via the stress mitogen-activated protein kinase (MAPK) signaling pathway. Herein we identify Gadd45a as an important negative regulator of two oncogenes commonly over-expressed in epithelial tumors: the p53 homologue DeltaNp63alpha and beta-catenin. DeltaNp63alpha is one of the several p63 isoforms and is the predominant species expressed in basal epidermal keratinocytes.

Helix-hairpin-helix motifs confer salt resistance and processivity on chimeric DNA polymerases.

Helix-hairpin-helix (HhH) is a widespread motif involved in sequence-nonspecific DNA binding. The majority of HhH motifs function as DNA-binding modules with typical occurrence of one HhH motif or one or two (HhH)(2) domains in proteins. We recently identified 24 HhH motifs in DNA topoisomerase V (Topo V).

The complete genome of hyperthermophile Methanopyrus kandleri AV19 and monophyly of archaeal methanogens.

We have determined the complete 1,694,969-nt sequence of the GC-rich genome of Methanopyrus kandleri by using a whole direct genome sequencing approach. This approach is based on unlinking of genomic DNA with the ThermoFidelase version of M. kandleri topoisomerase V and cycle sequencing directed by 2'-modified oligonucleotides (Fimers).

The domain organization and properties of individual domains of DNA topoisomerase V, a type 1B topoisomerase with DNA repair activities.

Topoisomerase V (Topo V) is a type IB (eukaryotic-like) DNA topoisomerase. It was discovered in the hyperthermophilic prokaryote Methanopyrus kandleri and is the only topoisomerase with associated apurinic/apyrimidinic (AP) site-processing activities. The structure of Topo V in the free and DNA-bound states was probed by limited proteolysis at 37 degrees C and 80 degrees C.