The KRAB-containing zinc-finger transcriptional regulator ZBRK1 activates SCA2 gene transcription through direct interaction with its gene product, ataxin-2.

Gene transcription is controlled by transcriptional regulators acting with specific co-regulators to allow gene activation and repression. Here, we report the identification of the KRAB-containing zinc-finger transcriptional regulator, ZBRK1, as an interaction partner of the SCA2 gene product ataxin-2. Furthermore, we discovered that an elevated ZBRK1 level resulted in increased ataxin-2 levels, whereas interference on transcriptional and protein levels of ZBRK1 yielded reduced ataxin-2 levels, suggesting that a complex comprising ZBRK1 and ataxin-2 regulates SCA2 gene transcription. A bioinformatic analysis utilizing the known ZBRK1 consensus DNA-binding motif revealed ZBRK1-binding sites in the SCA2 promoter. These predicted sites were experimentally validated by chromatin-immunoprecipitation experiments along with luciferase-based promoter analyses corroborating that SCA2 gene transcription is controlled by a ZBRK1/ataxin-2 complex. Finally, we demonstrate that SCA2 gene transcription is significantly reduced in colon tumors possessing low ZBRK1 transcripts. Thus, our results provide first evidence that ataxin-2 acts as a co-regulator of ZBRK1 activating its own transcription, thereby representing the first identified ZBRK1 co-activator.

Stimulation of acupoint ST-34 acutely improves gait performance in geriatric patients during rehabilitation: A randomized controlled trial.

OBJECTIVE: To determine whether a specific regimen of acupoint stimulation improved gait performance in geriatric patients. DESIGN: Multiple-blinded, randomized, controlled intervention trial. SETTING: Geriatric ward rehabilitation. PARTICIPANTS: 60 geriatric patients during rehabilitation. INTERVENTIONS: Both groups received a 1-time acupoint stimulation according to randomization. Stimulation of a verum acupoint (verum treatment) according to principles of traditional Chinese medicine was compared with a technically identical needle application on a nonacupoint (control treatment) in the control group. MAIN OUTCOME MEASURES: Descriptive parameters were documented by valid, established tests. Gait performance was objectively measured by an electronic walkway before needling and after needling. RESULTS: All gait parameters showed statistically significant improvement after verum treatment compared with control treatment (velocity, cadence, stride length, cycle time, step time, single support, double support: P values all <.05) except for the base of support (P=.163). Effect sizes achieved by 1-time stimulation of an acupoint were low and ranged from .08 to .24. No severe adverse clinical events related to the intervention occurred. CONCLUSIONS: Study results showed that a 1-time administration of a specific acupoint stimulation regimen statistically significantly improved gait performance during geriatric ward rehabilitation. If sustainability of effects can be documented, acupuncture may prove to be an inexpensive intervention that may mildly improve motor performance in frail geriatric patients.

Genomics and epigenomics of colorectal cancer.

Colorectal cancer is one of the most common cancer types worldwide and accounts for approximately 600,000 deaths annually. Work over the last decades has uncovered a number of tumor-suppressor and oncogenes which are frequently mutated and might thus be responsible for the malignant transformation. However, only with the development of new high-throughput technologies systematic analyses of the genome and epigenomes became feasible. While data generation has increased exponential, we are now faced with new challenges to transform these data into useful models that help predicting the outcome of genomic aberrations and to develop novel diagnostic and therapeutic strategies. As a basis for the modeling it is essential to understand and integrate current knowledge. We review previous and current ideas in colorectal cancer development and focus on a pathway oriented view. We show that colorectal cancer is a multilayer complex disease affecting the genome as well as the epigenome with direct consequences on the gene and microRNA (miRNA) expression signatures. The goal is to illustrate the current principles of colorectal cancer pathogenesis and to illustrate the need for elaborate computer modeling systems.

High-throughput miRNA and mRNA sequencing of paired colorectal normal, tumor and metastasis tissues and bioinformatic modeling of miRNA-1 therapeutic applications.

MiRNAs are discussed as diagnostic and therapeutic molecules. However, effective miRNA drug treatments with miRNAs are, so far, hampered by the complexity of the miRNA networks. To identify potential miRNA drugs in colorectal cancer, we profiled miRNA and mRNA expression in matching normal, tumor and metastasis tissues of eight patients by Illumina sequencing. We validated six miRNAs in a large tissue screen containing 16 additional tumor entities and identified miRNA-1, miRNA-129, miRNA-497 and miRNA-215 as constantly de-regulated within the majority of cancers. Of these, we investigated miRNA-1 as representative in a systems-biology simulation of cellular cancer models implemented in PyBioS and assessed the effects of depletion as well as overexpression in terms of miRNA-1 as a potential treatment option. In this system, miRNA-1 treatment reverted the disease phenotype with different effectiveness among the patients. Scoring the gene expression changes obtained through mRNA-Seq from the same patients we show that the combination of deep sequencing and systems biological modeling can help to identify patient-specific responses to miRNA treatments. We present this data as guideline for future pre-clinical assessments of new and personalized therapeutic options.

Genome-wide DNA methylation events in TMPRSS2-ERG fusion-negative prostate cancers implicate an EZH2-dependent mechanism with miR-26a hypermethylation.

UNLABELLED: Prostate cancer is the second most common cancer among men worldwide. Alterations in the DNA methylation pattern can be one of the leading causes for prostate cancer formation. This study is the first high-throughput sequencing study investigating genome-wide DNA methylation patterns in a large cohort of 51 tumor and 53 benign prostate samples using methylated DNA immunoprecipitation sequencing. Comparative analyses identified more than 147,000 cancer-associated epigenetic alterations. In addition, global methylation patterns show significant differences based on the TMPRSS2-ERG rearrangement status. We propose the hypermethylation of miR-26a as an alternative pathway of ERG rearrangement-independent EZH2 activation. The observed increase in differential methylation events in fusion-negative tumors can explain the tumorigenic process in the absence of genomic rearrangements. SIGNIFICANCE: In contrast to TMPRSS2-ERG -rearranged tumors, the pathomechanism for gene fusion-negative tumors is completely unclear. Using a sequencing-based approach, our work uncovers significant global epigenetic alterations in TMPRSS2-ERG gene fusion-negative tumors and provides a mechanistic explanation for the tumor formation process.

TLR2 has a detrimental role in mouse transient focal cerebral ischemia.

A significant up-regulation of Toll-like-receptor (TLR) mRNAs between 3 and 48 h reperfusion time after induction of transient focal cerebral ischemia for 1h was revealed by applying global gene expression profiling in postischemic mouse brains. Compared to TLR4 and TLR9, TLR2 proved to be the most significantly up-regulated TLR in the ipsilateral brain hemisphere. TLR2-protein was found to be expressed mainly in microglia in the postischemic brain tissue, but also in selected endothelial cells, neurons, and astrocytes. Additionally, TLR2-related genes with pro-inflammatory and pro-apoptotic capabilities were induced. Therefore we hypothesized that TLR2-signaling could exacerbate the primary brain damage after ischemia. Two days after induction of transient focal cerebral ischemia (1h), we found a significant decrease of the infarct volume in TLR2 deficient mice compared to wild type mice (75+/-5 vs. 42+/-7 mm(3)). We conclude that TLR2 up-regulation and TLR2-signaling are important events in focal cerebral ischemia and contribute to the deterioration of ischemic damage.