Tumor development is associated with decrease of TET gene expression and 5-methylcytosine hydroxylation

The TET (ten-eleven translocation) family of α-ketoglutarate (α-KG)-dependent dioxygenases catalyzes the sequential oxidation of 5-methylcytosine (5mC) to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine and 5-carboxylcytosine, leading to eventual DNA demethylation. The TET2 gene is a bona fide tumor suppressor frequently mutated in leukemia, and TET enzyme activity is inhibited in IDH1/2-mutated tumors by the oncometabolite 2-hydroxyglutarate, an antagonist of α-KG, linking 5mC oxidation to cancer development. We report here that the levels of 5hmC are dramatically reduced in human breast, liver, lung, pancreatic and prostate cancers when compared with the matched surrounding normal tissues. Associated with the 5hmC decrease is the substantial reduction of the expression of all three TET genes, revealing a possible mechanism for the reduced 5hmC in cancer cells. The decrease of 5hmC was also observed during tumor development in different genetically engineered mouse models. Together, our results identify 5hmC as a biomarker whose decrease is broadly and tightly associated with tumor development.

A novel way of visualizing the ductal and aortic arches by real-time three-dimensional ultrasound with live xPlane imaging

OBJECTIVE

To describe a novel method of visualizing the ductal and aortic arches by real-time three-dimensional echocardiography with live xPlane imaging.

METHODS

Live xPlane imaging was used to display the ductal- and aortic-arch views in 107 women with singleton pregnancies, including seven cases with suspected congenital heart defects (CHDs). The three vessels and trachea (3VT) view was obtained in such an orientation that either the pulmonary artery or the aorta was parallel to the direction of the ultrasound beam. The xPlane reference line was then placed across the targeted vessel, which in a normal case would provide an image of the corresponding arch view as a dual-image display.

RESULTS

Once the 3VT view had been obtained, live xPlane imaging showed the aortic and ductal arches in all 100 normal cases. In seven cases with suspected CHD, the 3VT view was abnormal in five cases and normal in the other two. However, the ductal-arch view demonstrated by live xPlane imaging was abnormal in five cases of conotruncal anomalies and normal in two cases in which conotruncal anomalies were excluded. CHDs were confirmed at autopsy following termination of pregnancy in five cases and on postnatal echocardiography in one case. The heart was found postnatally to be normal in one case of suspected CHD; in this case live xPlane imaging showed that the observed abnormal 3VT view was caused by a tortuous course of the thoracic aorta associated with an abnormal diaphragm.

CONCLUSION

Live xPlane imaging is a novel and relatively simple method of visualizing the ductal- and aortic-arch views, and may potentially be a useful tool in the screening of fetal conotruncal and aortic-arch anomalies.

Preliminary experience of endoscopic submucosal tunnel dissection for upper gastrointestinal submucosal tumors

BACKGROUND AND STUDY AIM

Although the majority of submucosal tumors (SMTs) are benign, some do have a malignant potential. Resection of SMTs would aid in establishing the diagnosis and may be curative. Our aim was to examine the feasibility and safety of a novel method for endoscopic resection of upper gastrointestinal SMTs.

PATIENTS AND METHODS

In 12 patients who presented with an upper gastrointestinal SMT of ≤40 mm located in the esophagus or cardia, a submucosal tunnel was endoscopically created starting approximately 5 cm proximal to the lesion. After careful submucosal dissection with carbon dioxide or air insufflation, the SMTs were completely removed, and the entrance of the tunnel closed using endoclips.

RESULTS

SMTs had a mean size of 19.5 mm (range 10-40 mm); eight were located in the esophagus and four in the cardia. SMT resection was successful in all patients with en bloc resection in 10 patients (83.3%) and resection in two pieces in the remaining two patients. The mean time required for the procedure was 48.3 minutes (range 30-60 minutes). Two patients had both pneumothorax and subcutaneous emphysema. All the complications resolved with conservative management.

CONCLUSIONS

In this pilot study, endoscopic submucosal tunnel dissection (ESTD) of esophageal and cardia SMTs was effective and appeared to be safe. Larger studies that also examine its application for gastric SMTs are warranted.

Regulation of glycolysis and gluconeogenesis by acetylation of PKM and PEPCK

Glycolysis is a catabolic process of glucose hydrolysis needed for energy and biosynthetic intermediates, whereas gluconeogenesis is a glucose production process important for maintaining blood glucose levels during starvation. Although they share many enzymes, these two processes are not simply the reverse of each other and are instead reciprocally regulated. Two key enzymes that regulate irreversible steps in these two processes are pyruvate kinase (PK) and phosphoenolpyruvate carboxy kinase (PEPCK), which catalyze the last and first step of glycolysis and gluconeogenesis, respectively, and are both regulated by lysine acetylation. Acetylation at Lys305 of the PKM (muscle form of PK) decreases its activity and also targets it for chaperone-mediated autophagy and subsequent lysosome degradation. Acetylation of PEPCK, on the other hand, targets it for ubiquitylation by the HECT E3 ligase, UBR5/EDD1, and subsequent proteasomal degradation. These studies established a model in which acetylation regulates metabolic enzymes via different mechanisms and also revealed cross talk between acetylation and ubiquitination. Given that most metabolic enzymes are acetylated, we propose that acetylation is a major posttranslational modifier that regulates cellular metabolism.

Benefits associated with a broad selection of dosage strengths for recombinant factor VIII products

Factor VIII (FVIII) concentrates for haemophilia A patients are dosed according to body weight. This results in a continuous range of prescribed doses, which challenges pharmacies to find dosage strengths closest to the prescribed dose while utilizing the least number of vials. This study was conducted to determine whether a broader selection of FVIII dosage strengths results in improved dispensing accuracy and an increased number of single-vial users. This research retrospectively analyzed a US pharmacy database of prescriptions filled in 2008. Recombinant FVIII (rFVIII) therapies were classified by the range of dosage strengths offered in 2008: Group 1 had three dosage strengths; Group 2 had four dosage strengths; and Group 3 had six dosage strengths. A total of 76,584 dispensed doses of rFVIII for 1,244 patients were included in this analysis. Dispensing accuracy (calculated as both the absolute and relative difference between dispensed and prescribed dose) was significantly better for Group 3 (23.2 IU, 1.2%) than Groups 1 (33.5 IU, 1.6%) and 2 (50.2 IU, 2.4%) (both P < 0.01). In addition, the average number of unique actual rFVIII potencies dispensed per month was highly correlated (-0.977) with dispensing accuracy for each dosage strength group. Among Groups 1, 2 and 3, 23.0%, 44.9% and 73.4% of patients, respectively, had at least one single vial option dispensed (P < 0.0001). A broader selection of rFVIII dosage strengths and more actual rFVIII potencies were associated with improved dispensing accuracy and more single-vial users. This may translate into less waste, cost savings, increased convenience and improved adherence to physician-prescribed regimens.

Effects of acoustic stimuli on neuronal activity in the auditory cortex of the rat

Spontaneous activity of cortical neurons exhibits alternative fluctuations of membrane potential consisting of phased depolarization called "up-state" and persistent hyperpolarization called "down-state" during slow wave sleep and anesthesia. Here, we examined the effects of sound stimuli (noise bursts) on neuronal activity by intracellular recording in vivo from the rat auditory cortex (AC). Noise bursts increased the average time in the up-state by 0.81+/-0.65 s (range, 0.27-1.74 s) related to a 10 s recording duration. The rise times of the spontaneous up-events averaged 69.41+/-18.04 ms (range, 40.10-119.21 ms), while those of the sound-evoked up-events were significantly shorter (p<0.001) averaging only 22.54+/-8.81 ms (range, 9.31-45.74 ms). Sound stimulation did not influence ongoing spontaneous up-events. Our data suggest that a sound stimulus does not interfere with ongoing spontaneous neuronal activity in auditory cortex but can evoke new depolarizations in addition to the spontaneous ones.

3D visualization of subcellular structures of Schizosaccharomyces pombe by hard X-ray tomography

Cellular structures of the fission yeast, Schizosaccharomyces pombe, were examined by using hard X-ray tomography. Since cells are nearly transparent to hard X-rays, Zernike phase contrast and heavy metal staining were introduced to improve image contrast. Through using such methods, images taken at 8 keV displayed sufficient contrast for observing cellular structures. The cell wall, the intracellular organelles and the entire structural organization of the whole cells were visualized in three-dimensional at a resolution better than 100 nm. Comparison between phase contrast and absorption contrast was also made, indicating the obvious advantage of phase contrast for cellular imaging at this energy. Our results demonstrate that hard X-ray tomography with Zernike phase contrast is suitable for cellular imaging. Its unique abilities make it have potential to become a useful tool for revealing structural information from cells, especially thick eukaryotic cells.

Abstract P3-08-01: The Influence of the BAD Apoptosis Pathway on Breast Cancer Progression and Relapse-Free Survival after Adjuvant Treatment

Objective. The phosphorylation status of the BCL2 Antagonist of Cell Death (BAD) protein influences cell survival and apoptosis. BAD phosphorylation is determined by the relative activity of a series of kinases and phosphatases within the BAD pathway. We therefore sought to evaluate the influence that expression of the BAD apoptosis pathway has on breast cancer progression and on clinical outcome in a series of breast cancer patients.

Methods. We used Principal components analysis to derive a BAD-pathway gene expression signature with a corresponding “pathway score” representing overall gene expression levels for BAD pathway genes. The BAD-pathway signature score was evaluated in clinical-genomic breast cancer datasets obtained from a total of 502 patients, including intra-ductal hyperplasia (n=8), ductal carcinoma in-situ (n=30), and three separate data sets of invasive ductal carcinoma patient samples (n=23, n=286, n=155). The influence of the BAD-pathway signature score on breast cancer progression and relapse-free survival was evaluated by student's t-test and Kaplan Meier/log-rank test, respectively.

Results. We developed a 48-gene BAD-pathway signature, the expression score of which decreased with progression from intra-ductal hyperplasia through ductal carcinoma in-situ and invasive ductal carcinoma (p=0.0004). Furthermore, BAD-pathway signature score was associated with relapse free survival from breast cancer in two independent clinical-genomic datasets (n=286, p=0.01; n=155, p=0.02). Conclusions.BAD pathway gene expression is associated with breast cancer progression and disease-free survival. The pathway represents an appealing human cancer prognostic biomarker and therapeutic target. Figures available in online version.

Long non-coding RNA ANRIL is required for the PRC2 recruitment to and silencing of p15(INK4B) tumor suppressor gene

A 42 kb region on human chromosome 9p21 encodes for three distinct tumor suppressors, p16(INK4A), p14(ARF) and p15(INK4B), and is altered in an estimated 30-40% of human tumors. The expression of the INK4A-ARF-INK4B gene cluster is silenced by polycomb during normal cell growth and is activated by oncogenic insults and during aging. How the polycomb is recruited to repress this gene cluster is unclear. Here, we show that expression of oncogenic Ras, which stimulates the expression of p15(INK4B) and p16(INK4A), but not p14(ARF), inhibits the expression of ANRIL (antisense non-coding RNA in the INK4 locus), a 3.8 kb-long non-coding RNA expressed in the opposite direction from INK4A-ARF-INK4B. We show that the p15(INK4B) locus is bound by SUZ12, a component of polycomb repression complex 2 (PRC2), and is H3K27-trimethylated. Notably, depletion of ANRIL disrupts the SUZ12 binding to the p15(INK4B) locus, increases the expression of p15(INK4B), but not p16(INK4A) or p14(ARF), and inhibits cellular proliferation. Finally, RNA immunoprecipitation demonstrates that ANRIL binds to SUZ12 in vivo. Collectively, these results suggest a model in which ANRIL binds to and recruits PRC2 to repress the expression of p15(INK4B) locus.

Up-regulated expression of Notch1 and Jagged1 in human colon adenocarcinoma

Deregulated expression of Notch molecules is observed in many malignant tumors, however, the expression of Notch1 and Jagged1 in colon adenocarcinoma is still unknown. This study is to investigate the expression of Notch1 and Jagged1 in human colon adenocarcinoma. Sixty-five human colon adenocarcinoma and 60 adjacent nontumor colon tissue sections were detected by immunohistochemistry. Ten paired fresh surgical human colon adenocarcinoma and adjacent nontumor colon samples were analyzed by Western blot and RT-PCR. Both Notch1 and Jagged1 were expressed in the cytoplasm of neoplastic cells of colon adenocarcinoma tissue. The protein and mRNA levels of both molecules were higher in colon adenocarcinoma than in adjacent nontumor tissue. Moreover, Notch1 was positively correlated with tumor stage. This investigation demonstrates that Notch1 and Jagged1 are up-regulated in human colon adenocarcinoma and suggests that Notch1/Jagged1 signaling might play a role in the development of colon adenocarcinoma.

Operational definitions improve reliability of the age-related white matter changes scale

BACKGROUND AND PURPOSE

Although the age-related white matter changes (ARWMC) scale has been advocated to be applicable to both MRI and CT for assessing the severity of WMC, its inter-rater reliability on CT is only fair. We aimed to operationalize the ARWMC scale and investigate the effect of this operationalization on the reliability and validity on MRI and CT.

METHODS

Operational definitions of the ARWMC scale were derived from Erkinjuntti research criteria for subcortical vascular dementia and Scheltens scale. Using original and operationalized ARWMC scale, eight observers recorded the time for rating per MRI and per CT. We investigated the inter-rater and intrarater reliability as well as validity against volume using data from 97 stroke patients.

RESULTS

Inter-rater reliability of the operationalized scale on CT (0.874, 95% confidence interval [0.780-0.934]) was better than the original scale (0.569, 95% confidence interval [0.247-0.775]). Its intrarater reliability on CT (0.869) and reliability on MRI (inter-rater: 0.860; intrarater: 0.838) was comparable with the original scale (CT intrarater: 0.750 and on MRI inter-rater: 0.845; intrarater: 0.853). The time required to administer the operationalized scale (4'2″ for MRI and 1'18″ for CT) was similar to that of the original scale (3'56″ for MRI and 1'16″ for CT). The original scale and operationalized scale also significantly correlated with WMC volume (operationalized scale ρ = 0.613, P < 0.001, original scale ρ = 0.638, P < 0.001).

CONCLUSION

Operational definitions improve the inter-rater reliability of ARWMC scale on CT, and it correlates with volumetric measurement.

Crystal growth, structure, and physical properties of Ln(Ag, Al, Si)₂ (Ln = Ce and Gd)

Single crystals of CeM₂ and GdM₂ (M = Ag, Al, and Si) were grown by the flux growth technique and characterized by means of single crystal x-ray diffraction, magnetic susceptibility, resistivity, and heat capacity measurements. CeM₂ and GdM₂ crystallize in the tetragonal I4(1)/amd space group with the α-ThSi₂ structure type with lattice parameters a ~4.2 Å and c ~14.4 Å. Curie-Weiss behavior is observed for both analogues with CeM₂ ordering first ferromagnetically at 11 K with a second antiferromagnetic transition at 8.8 K while GdM₂ orders antiferromagnetically at 24 K. Heat capacity measurements on CeM₂ show two magnetic transitions at 10.8 and 8.8 K with an electronic specific heat coefficient, γ(0), of ~53 mJ K(-2) mol(-1). The entropy at the magnetic transition is less than the expected Rln2 for CeM₂, reinforcing the assertions of an enhanced mass state and Kondo behavior being observed in the resistivity.