Citations

Abstract Growing evidence supports a role for the unfolded protein response (UPR) in carcinogenesis; however, the precise molecular mechanisms underlying this phenomenon remain elusive. Herein, we identified the circadian clock PER1 mRNA as a novel substrate of the endoribonuclease activity of the UPR sensor IRE1α. Analysis of the mechanism shows that IRE1α endoribonuclease activity decreased PER1 mRNA in tumor cells without affecting PER1 gene transcription. Inhibition of IRE1α signaling using either siRNA-mediated silencing or a dominant-negative strategy prevented PER1 mRNA decay, reduced tumorigenesis, and increased survival, features that were reversed upon PER1 silencing. Clinically, patients showing reduced survival have lower levels of PER1 mRNA expression and increased splicing of XBP1, a known IRE-α substrate, thereby pointing toward an increased IRE1α activity in these patients. Hence, we describe a novel mechanism connecting the UPR and circadian clock components in tumor cells, thereby highlighting the importance of this interplay in tumor development. Cancer Res; 73(15); 4732–43. ©2013 AACR.

Accumulating pre-clinical data suggests that matrix metalloproteinase (MMP) expression plays a critical role in the pathophysiology of secondary brain injury. We conducted a prospective multimodal monitoring study in order to characterize the temporal MMP response after severe traumatic brain injury (TBI) in eight critically ill humans and its relationship with outcomes. High-cutoff, cerebral microdialysis ( n =8); external ventricular drainage ( n =3); and arterial and jugular venous bulb catheters were used to collect microdialysate, cerebrospinal fluid, and arterial and jugular bulb blood over 6 days. Levels of MMP-8 and -9 were initially high in microdialysate and then gradually declined over time. After these MMPs decreased, a spike in the microdialysate levels of MMP-2 and -3 occurred, followed by a gradual rise in the microdialysate concentration of MMP-7. Use of generalized estimating equations suggested that MMP-8 concentration in microdialysate was associated with mortality ( p =0.019) and neurological outcome at hospital discharge ( p =0.013). Moreover, the mean microdialysate concentration of MMP-8 was 2.4-fold higher among those who died after severe TBI than in those who survived. Mean microdialysate levels of MMP-8 also rose with increasing intracranial pressure (ICP), whereas those of MMP-7 decreased with increasing cerebral perfusion pressure (CPP). Significant changes in the mean microdialysate concentrations of MMP-1, -2, -3, and -9 and MMP-1, -2, -3, -7, and -9 also occurred with increases in microdialysate glucose and the lactate/pyruvate ratio, respectively. These results imply that monitoring of MMPs following severe TBI in humans is feasible, and that their expression may be associated with clinical outcomes, ICP, CPP, and cerebral metabolism.

Background and Study Aims. The presence of an implantable electromechanical cardiac device (IED) has long been considered a relative contraindication to the performance of video capsule endoscopy (CE). The primary aim of this study was to evaluate the safety of CE in patients with IEDs. A secondary purpose was to determine whether IEDs have any impact on images captured by CE.Patients and Methods.A retrospective chart review of all patients who had a capsule endoscopy at Mayo Clinic in Scottsdale, AZ, USA, or Rochester, MN, USA, (January 2002 to June 2010) was performed to identify CE studies done on patients with IEDs. One hundred and eighteen capsule studies performed in 108 patients with IEDs were identified and reviewed for demographic data, method of preparation, and study data.Results.The most common indications for CE were obscure gastrointestinal bleeding (77%), anemia (14%), abdominal pain (5%), celiac disease (2%), diarrhea (1%), and Crohn’s disease (1%). Postprocedure assessments did not reveal any detectable alteration on the function of the IED. One patient with an ICD had a 25-minute loss of capsule imaging due to recorder defect. Two patients with LVADs had interference with capsule image acquisition.Conclusions.CE did not interfere with IED function, including PM, ICD, and/or LVAD and thus appears safe. Additionally, PM and ICD do not appear to interfere with image acquisition but LVAD may interfere with capsule images and require that capsule leads be positioned as far away as possible from the IED to assure reliable image acquisition.

Aberrant connectivity is implicated in many neurological and psychiatric disorders, including Alzheimer’s disease and schizophrenia. However, other than a few disease-associated candidate genes, we know little about the degree to which genetics play a role in the brain networks; we know even less about specific genes that influence brain connections. Twin and family-based studies can generate estimates of overall genetic influences on a trait, but genome-wide association scans (GWASs) can screen the genome for specific variants influencing the brain or risk for disease. To identify the heritability of various brain connections, we scanned healthy young adult twins with high-field, high-angular resolution diffusion MRI. We adapted GWASs to screen the brain’s connectivity pattern, allowing us to discover genetic variants that affect the human brain’s wiring. The association of connectivity with the SPON1 variant at rs2618516 on chromosome 11 (11p15.2) reached connectome-wide, genome-wide significance after stringent statistical corrections were enforced, and it was replicated in an independent subsample. rs2618516 was shown to affect brain structure in an elderly population with varying degrees of dementia. Older people who carried the connectivity variant had significantly milder clinical dementia scores and lower risk of Alzheimer’s disease. As a posthoc analysis, we conducted GWASs on several organizational and topological network measures derived from the matrices to discover variants in and around genes associated with autism ( MACROD2 ), development ( NEDD4 ), and mental retardation ( UBE2A ) significantly associated with connectivity. Connectome-wide, genome-wide screening offers substantial promise to discover genes affecting brain connectivity and risk for brain diseases.

Abstract Purpose: Controversy exists about CYP2D6 genotype and tamoxifen efficacy. Experimental Design: A matched case–control study was conducted using the Austrian Breast and Colorectal Cancer Study Group Trial 8 (ABCSG8) that randomized postmenopausal women with estrogen receptor (ER)-positive breast cancer to tamoxifen for 5 years (arm A) or tamoxifen for 2 years followed by anastrozole for 3 years (arm B). Cases had disease recurrence, contralateral breast cancer, second non–breast cancer, or died. For each case, controls were identified from the same treatment arm of similar age, surgery/radiation, and tumor–node—metastasis (TNM) stage. Genotyping was conducted for alleles associated with no (PM; *3, *4, *6), reduced (IM; *10, and *41), and extensive (EM: absence of these alleles) CYP2D6 metabolism. Results: The common CYP2D6*4 allele was in Hardy–Weinberg equilibrium. In arm A during the first 5 years of therapy, women with two poor alleles [PM/PM: OR, 2.45; 95% confidence interval (CI), 1.05–5.73, P = 0.04] and women with one poor allele (PM/IM or PM/EM: OR, 1.67; 95% CI, 0.95–2.93; P = 0.07) had a higher likelihood of an event than women with two extensive alleles (EM/EM). In years 3 to 5 when patients remained on tamoxifen (arm A) or switched to anastrozole (arm B), PM/PM tended toward a higher likelihood of a disease event relative to EM/EM (OR, 2.40; 95% CI, 0.86–6.66; P = 0.09) among women on arm A but not among women on arm B (OR, 0.28; 95% CI, 0.03–2.30). Conclusion: In ABCSG8, the negative effects of reduced CYP2D6 metabolism were observed only during the period of tamoxifen administration and not after switching to anastrozole. Clin Cancer Res; 19(2); 500–7. ©2012 AACR.

Hyperkinetic movement disorders are uncommon after acute ischemic stroke. Since these movement disorders are rarely the initial manifestation of acute cerebral ischemia, their presence may result in diagnostic uncertainty or it may inappropriately delay intravenous thrombolytic therapy for ischemic stroke. Hemichorea–hemiballism (HC-HB) is one of the more frequently encountered hyperkinetic movement disorders occurring in conjunction with stroke. Although HC-HB may result from a stroke mimic, the acute onset should prompt rapid evaluation and consideration for the presence of stroke along with its time-dependent therapies including recombinant tissue plasminogen activator (rtPA). In this article, we describe a case of a patient with acute cerebral ischemia presenting clinically with HC-HB, who was given intravenous rtPA therapy despite an initially negative, early diffusion-weighted magnetic resonance imaging (MRI). Follow-up brain MRI performed 24 hours after the initiation of thrombolytic therapy confirmed acute infarction in the contralateral striatum. The patient had near-complete resolution of her HC-HB on discharge and had no complications related to the administration of intravenous rtPA.