Citations

Genetic College Many genomic elements in humans are associated with behavior, including educational attainment. In a genome-wide association study including more than 100,000 samples, Rietveld et al. (p. 1467 , published online 30 May; see the Perspective by Flint and Munafò ) looked for genes related to educational attainment in Caucasians. Small genetic effects at three loci appeared to impact educational attainment.

This white paper, prepared by a working group of the Catholic Medical Association, provides a commentary on a new type of end-of-life document called a POLST form (Physician Orders for Life-Sustaining Treatment) as well as on its model (or “paradigm”) for implementation across the United States. After an introductory section reviewing the origin, goals, and standard defenses of the POLST paradigm and form, the paper offers a critical analysis of POLST, including an analysis of the risks that POLST poses to sound clinical and ethical decision-making. The paper ends with several recommendations to help Catholic healthcare professionals and institutions better address the challenges of end-of-life care with alternatives to POLST.

A Na+ current is present in human jejunal circular smooth muscle cells. The aim of the present study was to determine the role of the cytoskeleton in the regulation of the Na+ current. Whole cell currents were recorded by using standard patch-clamp techniques with Cs+ in the pipette to block K+currents. Cytochalasin D and gelsolin were used to disrupt the actin cytoskeleton and phalloidin to stabilize it. Colchicine was used to disassemble the microtubule cytoskeleton (and intermediate filaments) and paclitaxel to stabilize it. Acrylamide was used to disrupt the intermediate filament cytoskeleton. Perfusion of the recording chamber at 10 ml/min increased peak Na+ current recorded from jejunal smooth muscle cells by 27 ± 3%. Cytochalasin D and gelsolin abolished the perfusion-induced increase in Na+current, whereas incubation with phalloidin, colchicine, paclitaxel, or acrylamide had no effect. In conclusion, the Na+ current expressed in human jejunal circular smooth muscle cells appears to be regulated by the cytoskeleton. An intact actin cytoskeleton is required for perfusion-induced activation of the Na+ current.

Smooth muscle exhibits mechanosensitivity independent of neural input, suggesting that mechanosensitive pathways reside within smooth muscle cells. The native L-type calcium current recorded from human intestinal smooth muscle is modulated by stretch. To define mechanosensitive mechanisms involved in the regulation of smooth muscle calcium entry, we cloned the α1C L-type calcium channel subunit (CaV1.2) from human intestinal smooth muscle and expressed the channel in a heterologous system. This channel subunit retained mechanosensitivity when expressed alone or coexpressed with a β2 calcium channel subunit in HEK-293 or Chinese hamster ovary cells. The heterologously expressed human cardiac α1C splice form also demonstrated mechanosensitivity. Inhibition of kinase signaling did not affect mechanosensitivity of the native channel. Truncation of the α1C COOH terminus, which contains an inhibitory domain and a proline-rich domain thought to mediate mechanosensitive signaling from integrins, did not disrupt mechanosensitivity of the expressed channel. These data demonstrate mechanical regulation of calcium entry through molecularly identified L-type calcium channels in mammalian cells and suggest that the mechanosensitivity resides within the pore forming α1C-subunit.

Abstract Introduction: Multivariable models that predict biochemical recurrence (BCR) can indicate patients at higher risk for developing clinical progression after prostatectomy. However, most patients that experience BCR do not metastasize or die from prostate cancer, making BCR an unreliable surrogate endpoint. In this study we compared the clinical and genomic characteristics of prostatectomy patients in order to better delineate the relationship between BCR and aggressive prostate cancer. Methods: Postoperative patients were retrospectively classified into three outcome groups: NED (no evidence of disease recurrence); BCR-only (patients that experienced BCR but didn't have progressive disease as evidenced by bone or CT scans); and CP (clinical progression with BCR plus positive CT or bone scans). Patient specimens were from the Mayo Clinic Radical Prostatectomy Registry, selected using a nested case-control design with 14 years median follow-up. RNA expression levels from FFPE tumor specimens were measured with 1.4 million feature whole-transcriptome oligonucleotide microarrays on 106 matching patients from each outcome group (total 318 patients). We analyzed the clinical covariates of the outcome groups in a pairwise manner (NED vs. BCR-only; NED vs. CP; CP vs. BCR-only), using a conditional logistic model in univariable and multivariable analyses. We performed feature reduction for the genomic data set using Kruskal-Wallis tests and regularized logistic regression. Principal Component Analysis (PCA) was used to quantify the variance of the genomic data with respect to the patient outcome groups. Results: Our initial hypothesis was that all three outcome groups would have different clinical and genomic characteristics. Univariable analysis of clinical variables failed to show statistically significant differences between NED and BCR-only groups. Multivariable analysis of the clinical variables also failed to show statistically significant differences between NED and BCR-only groups. Among the clinical variables only pathological Gleason score was statistically significant when comparing the BCR-only vs. CP and NED vs. CP groups. Genomic analysis found 363 coding and non-coding features that passed thresholds for differential expression between the three outcome groups. PCA established that the primary source of variance in the genomic data stemmed from the separation of CP from NED and BCR-only patients; whereas only a small amount of variance separates NED and BCR-only groups. The 363 features were further compared in the three outcome groups using Wilcoxon tests, adjusting for false-discovery using Benjamini-Hochberg. At a cutoff of p < 0.001 there were no features differentially expressed between NED and BCR-only, while 52 and 34 statistically significant features were found in the NED vs. CP and CP vs. BCR-only comparisons, respectively. Conclusion: Considering the clinical and genomic results together, we find that: 1) Patients that developed clinical progression were significantly different from those that did not, irrespective of whether they experienced BCR or not; 2) the NED and BCR-only groups were statistically very similar to each other. We therefore conclude that BCR may not be the most appropriate endpoint for predictive models that attempt to stratify patients at risk for progression. This abstract is also presented as Poster B44. Citation Format: Anamaria Crisan, Elai Davicion, R. Jeffery Karnes, Robert B. Jenkins, Mercedeh H. Ghadessi, Christine Buerki, Eric J. Bergstrahl, Nicholas Erho, Ismael A. Vergara, Karla V. Ballman, Peter C. Black, Timothy J. Triche. Biochemical recurrence is not a definitive surrogate endpoint for development of clinically useful predictive models for post-prostatectomy patients [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr PR4.

Purpose It has been suggested that PTEN, a negative regulator of PI3K/AKT signaling, is involved in tumor sensitivity to trastuzumab. We investigated the association between tumor PTEN protein expression and disease-free survival (DFS) of patients randomly assigned to receive chemotherapy alone (arm A) or chemotherapy with sequential (arm B) or concurrent trastuzumab (arm C) in the phase III early-stage human epidermal growth factor receptor 2 (HER2) –positive trial—North Central Cancer Treatment Group (NCCTG) N9831. Patients and Methods The intensity and percentage of invasive cells with cytoplasmic PTEN staining were determined in tissue microarray sections containing three cores per block (n = 1,286) or in whole tissue sections (WS; n = 516) by using standard immunohistochemistry (138G6 monoclonal antibody). Tumors were considered positive for PTEN (PTEN-positive) if any core or WS had any invasive cells with ≥ 1+ staining. Median follow-up was 6.0 years. Results Of 1,802 patients included in this analysis (of 3,505 patients registered to N9831), 1,342 (74%) had PTEN-positive tumors. PTEN positivity was associated with hormone receptor negativity (χ2 P < .001) and nodal positivity (χ2 P = .04). PTEN did not have an impact on DFS within the various arms. Comparing DFS of arm C to arm A, patients with PTEN-positive and PTEN-negative tumors had hazard ratios (HRs) of 0.65 (P = .003) and 0.47 (P = .005), respectively (interaction P = .16). For arm B versus arm A, patients with PTEN-positive and PTEN-negative tumors had HRs of 0.70 (P = .009) and 0.85 (P = .44), respectively (interaction P = .47). Conclusion In contrast to selected preclinical and limited clinical studies suggesting a decrease in trastuzumab sensitivity in patients with PTEN-negative tumors, our data show benefit of adjuvant trastuzumab for patients with HER2-positive breast cancer, independent of tumor PTEN status.

The signaling molecule adenosine has been implicated in attenuating acute lung injury (ALI). Adenosine signaling is terminated by its uptake through equilibrative nucleoside transporters (ENTs). We hypothesized that ENT‐dependent adenosine uptake could be targeted to enhance adenosine‐mediated lung protection. To address this hypothesis, we exposed mice to high‐pressure mechanical ventilation to induce ALI. Initial studies demonstrated time‐dependent repression of ENT1 and ENT2 transcript and protein levels during ALI. To examine the contention that ENT repression represents an endogenous adaptive response, we performed functional studies with the ENT inhibitor dipyridamole. Dipyridamole treatment (1 mg/kg; EC 50 =10 μM) was associated with significant increases in ALI survival time (277 vs. 395 min; P <0.05). Subsequent studies in gene‐targeted mice for Ent1 or Ent2 revealed a selective phenotype in Ent2 ‐/‐ mice, including attenuated pulmonary edema and improved gas exchange during ALI in conjunction with elevated adenosine levels in the bronchoalveolar fluid. Furthermore, studies in genetic models for adenosine receptors implicated the A 2B adenosine receptor (Adora2b) in mediating ENT‐dependent lung protection. Notably, dipyridamole‐dependent attenuation of lung inflammation was abolished in mice with alveolar epithelial Adora2b gene deletion. Our newly identified crosstalk pathway between ENT2 and alveolar epithelial Adora2b in lung protection during ALI opens possibilities for combined therapies targeted to this protein set.—Eckle, T., Hughes, K., Ehrentraut, H., Brodsky, K. S., Rosenberger, P., Choi, D.‐S., Ravid, K., Weng, T., Xia, Y., Blackburn, M. R.Eltzschig, H. K., Crosstalk between the equilibrative nucleoside transporter ENT2 and alveolar Adora2b adenosine receptors dampens acute lung injury. FASEB J. 27, 3078–3089 (2013). www.fasebj.org