Benzomorphan and non-benzomorphan agonists differentially alter sigma-1 receptor quaternary structure, as does types of cellular stress

Sigma-1 receptor (S1R) is a calcium-sensitive, ligand-operated receptor chaperone present on the endoplasmic reticulum (ER) membrane. S1R plays an important role in ER-mitochondrial inter-organelle calcium signaling and cell survival. S1R and its agonists confer resilience against various neurodegenerative diseases; however, the molecular mechanism of S1R is not yet fully understood. At resting state, S1R is either in a monomeric or oligomeric state but the ratio of these concentrations seems to change upon activation of S1R. S1R is activated by either cellular stress, such as ER-calcium depletion, or ligands. While the effect of ligands on S1R quaternary structure remains unclear, the effect of cellular stress has not been studied. In this study we utilize cellular and an in-vivo model to study changes in quaternary structure of S1R upon activation. We incubated cells with cellular stressors (H2O2 and thapsigargin) or exogenous ligands, then quantified monomeric and oligomeric forms. We observed that benzomorphan-based S1R agonists induce monomerization of S1R and decrease oligomerization, which was confirmed in the liver tissue of mice injected with (+)-Pentazocine. Antagonists block this effect but do not induce any changes when used alone. Oxidative stress (H2O2) increases the monomeric/oligomeric S1R ratio whereas ER calcium depletion (thapsigargin) has no effect. We also analyzed the oligomerization ability of various truncated S1R fragments and identified the fragments favorizing oligomerization. In this publication we demonstrate that quaternary structural changes differ according to the mechanism of S1R activation. Therefore, we offer a novel perspective on S1R activation as a nuanced phenomenon dependent on the type of stimulus.

Establishment and characterization of a non-gestational choriocarcinoma patient-derived xenograft model

BACKGROUND

Non-gestational choriocarcinoma (NGC) is a rare subtype of malignant germ cell tumour and there is no consensus on its treatment. The lack of suitable preclinical models for NGC is a challenge in drug discovery research. Patient-derived xenograft (PDX) models recapitulate the tumour microenvironment of the original cancer tissue. Therefore, they have received considerable attention for studies on rare cancer. Here, we aimed to establish a PDX model from a patient with recurrent NGC.

METHODS

Fresh NGC tumour tissue was immediately transplanted into a severely immune-deficient mouse (NOD.Cg-Prkdcscid1l2rgtm1Wjl/SzJ) and maintained for more than three in vivo passages. Subsequently, we evaluated the molecular characteristics of the PDX model using immunohistochemistry, polymerase chain reaction, and RNA sequencing. Moreover, the PDX tumours were transplanted into BALB/c nude mice, and we evaluated their sensitivity for cisplatin and methotrexate.

RESULTS

The PDX tumour maintained the morphological features of NGC. Moreover, Immunohistochemistry revealed that the human chorionic gonadotropin, cytokeratin 7, and EpCAM expression levels were similar to those in the primary tumour. Furthermore, serum human chorionic gonadotropin levels were elevated in both the primary tumour and the PDX models. Additionally, using PCR analysis with species-specific primers, we confirmed that the PDX tumour contained human genes and was derived from human tissue. Moreover, the gene expression profile of the NGC was compared with that of epithelial ovarian cancer samples and cell lines, and 568 dysregulated genes in the NGC were extracted. The expression of the dysregulated genes in PDX was significantly correlated with that in the primary tumour (R2 = 0.873, P < 0.001). Finally, we demonstrated that the PDX tumour was sensitive to cisplatin and methotrexate; therefore, its clinical response to the agents was similar to that of the primary tumour.

CONCLUSIONS

We successfully established a PDX model of NGC, to the best of our knowledge, for the first time. The established PDX retained the molecular and transcriptome characteristics of the primary tumour and can be used to predict drug effects. It may facilitate further research and the development of novel therapeutic agents for NGC.

SIGMAR1 Confers Innate Resilience against Neurodegeneration

The sigma-1 receptor (SIGMAR1) is one of a kind: a receptor chaperone protein. This 223 amino acid-long protein is enriched at the mitochondria-associated endoplasmic reticulum membrane (MAM), a specialized microdomain of the endoplasmic reticulum that is structurally and functionally connected to the mitochondria. As a receptor, SIGMAR1 binds a wide spectrum of ligands. Numerous molecules targeting SIGMAR1 are currently in pre-clinical or clinical development. Interestingly, the range of pathologies covered by these studies is broad, especially with regard to neurodegenerative disorders. Upon activation, SIGMAR1 can translocate and interact with other proteins, mostly at the MAM but also in other organelles, which allows SIGMAR1 to affect many cellular functions. During these interactions, SIGMAR1 exhibits chaperone protein behavior by participating in the folding and stabilization of its partner. In this short communication, we will shed light on how SIGMAR1 confers protection against neurodegeneration to the cells of the nervous system and why this ability makes SIGMAR1 a multifunctional therapeutic prospect.

Nucleoporin POM121 signals TFEB-mediated autophagy via activation of SIGMAR1/sigma-1 receptor chaperone by pridopidine

Macroautophagy/autophagy is an essential process for cellular survival and is implicated in many diseases. A critical step in autophagy is the transport of the transcription factor TFEB from the cytosol into the nucleus, through the nuclear pore (NP) by KPNB1/importinβ1. In the C9orf72 subtype of amyotrophic lateral sclerosis-frontotemporal lobar degeneration (ALS-FTD), the hexanucleotide (G4C2)RNA expansion (HRE) disrupts the nucleocytoplasmic transport of TFEB, compromising autophagy. Here we show that a molecular chaperone, the SIGMAR1/Sigma-1 receptor (sigma non-opioid intracellular receptor 1), facilitates TFEB transport into the nucleus by chaperoning the NP protein (i.e., nucleoporin) POM121 which recruits KPNB1. In NSC34 cells, HRE reduces TFEB transport by interfering with the association between SIGMAR1 and POM121, resulting in reduced nuclear levels of TFEB, KPNB1, and the autophagy marker LC3-II. Overexpression of SIGMAR1 or POM121, or treatment with the highly selective and potent SIGMAR1 agonist pridopidine, currently in phase 2/3 clinical trials for ALS and Huntington disease, rescues all of these deficits. Our results implicate nucleoporin POM121 not merely as a structural nucleoporin, but also as a chaperone-operated signaling molecule enabling TFEB-mediated autophagy. Our data suggest the use of SIGMAR1 agonists, such as pridopidine, for therapeutic development of diseases in which autophagy is impaired.Abbreviations: ALS-FTD, amyotrophic lateral sclerosis-frontotemporal dementiaC9ALS-FTD, C9orf72 subtype of amyotrophic lateral sclerosis-frontotemporal dementiaCS, citrate synthaseER, endoplasmic reticulumGSS, glutathione synthetaseHRE, hexanucleotide repeat expansionHSPA5/BiP, heat shock protein 5LAMP1, lysosomal-associated membrane protein 1MAM, mitochondria-associated endoplasmic reticulum membraneMAP1LC3/LC3, microtubule-associated protein 1 light chain 3NP, nuclear poreNSC34, mouse motor neuron-like hybrid cell lineNUPs, nucleoporinsPOM121, nuclear pore membrane protein 121SIGMAR1/Sigma-1R, sigma non-opioid intracellular receptor 1TFEB, transcription factor EBTMEM97/Sigma-2R, transmembrane protein 97.

Level of vascular inflammation is higher in acute coronary syndromes compared to chronic coronary disease

Background

Vascular inflammation has been recognized as one of the key factors in the pathogenesis of acute coronary syndromes (ACS). Peri-coronary adipose tissue (PCAT) attenuation by computed tomography angiography (CTA) has emerged as a marker specific for coronary artery inflammation. We examined the relationship between clinical presentation and coronary artery inflammation assessed by PCAT attenuation and coronary plaque characteristics.

Methods

Patients with ACS or stable angina pectoris (SAP) who underwent pre-intervention coronary CTA and optical coherence tomography (OCT) were enrolled. PCAT attenuation was measured around the culprit lesion and in the proximal 40 mm of all coronary arteries. PCAT attenuation and OCT findings were compared between patients with ACS versus SAP.

Results

Among 471 patients (ACS: 198, SAP: 273), PCAT attenuation was higher in ACS patients than in SAP patients both at the culprit plaque level (−67.5±9.6 Hounsfield unit [HU] vs. −71.5±11.0 HU, p&lt;0.001) and the culprit vessel level (−68.3±7.7 HU vs. −71.1±7.9 HU, p&lt;0.001). The mean PCAT attenuation of all 3 coronary arteries was also significantly higher in ACS patients than in SAP patients (−68.8±6.3 HU vs. −70.5±7.1 HU, p=0.007). After adjusting patient characteristics, not only thin-cap fibroatheroma (OR: 2.44; 95% CI: 1.63–3.65) and macrophages (OR: 2.07; 95% CI: 1.34–3.21) but also PCAT attenuation in the culprit plaque (OR: 1.04; 95% CI: 1.02–1.06) was associated with the clinical presentation of ACS.

Conclusions

PCAT attenuation at culprit plaque, culprit vessel, and pan-coronary levels was higher in ACS patients than in SAP patients. Vascular inflammation appears to play a crucial role in the development of ACS.

Funding Acknowledgement

Type of funding sources: None.

Knocking Out Sigma-1 Receptors Reveals Diverse Health Problems

Sigma-1 receptor (Sig-1R) is a protein present in several organs such as brain, lung, and heart. In a cell, Sig-1R is mainly located across the membranes of the endoplasmic reticulum and more specifically at the mitochondria-associated membranes. Despite numerous studies showing that Sig-1R could be targeted to rescue several cellular mechanisms in different pathological conditions, less is known about its fundamental relevance. In this review, we report results from various studies and focus on the importance of Sig-1R in physiological conditions by comparing Sig-1R KO mice to wild-type mice in order to investigate the fundamental functions of Sig-1R. We note that the Sig-1R deletion induces cognitive, psychiatric, and motor dysfunctions, but also alters metabolism of heart. Finally, taken together, observations from different experiments demonstrate that those dysfunctions are correlated to poor regulation of ER and mitochondria metabolism altered by stress, which could occur with aging.

Activation of the sigma-1 receptor chaperone alleviates symptoms of Wolfram syndrome in preclinical models

The Wolfram syndrome is a rare autosomal recessive disease affecting many organs with life-threatening consequences; currently, no treatment is available. The disease is caused by mutations in the WSF1 gene, coding for the protein wolframin, an endoplasmic reticulum (ER) transmembrane protein involved in contacts between ER and mitochondria termed as mitochondria-associated ER membranes (MAMs). Inherited mutations usually reduce the protein's stability, altering its homeostasis and ultimately reducing ER to mitochondria calcium ion transfer, leading to mitochondrial dysfunction and cell death. In this study, we found that activation of the sigma-1 receptor (S1R), an ER-resident protein involved in calcium ion transfer, could counteract the functional alterations of MAMs due to wolframin deficiency. The S1R agonist PRE-084 restored calcium ion transfer and mitochondrial respiration in vitro, corrected the associated increased autophagy and mitophagy, and was able to alleviate the behavioral symptoms observed in zebrafish and mouse models of the disease. Our findings provide a potential therapeutic strategy for treating Wolfram syndrome by efficiently boosting MAM function using the ligand-operated S1R chaperone. Moreover, such strategy might also be relevant for other degenerative and mitochondrial diseases involving MAM dysfunction.

Unveiling unconventional magnetism at the surface of Sr2RuO4

Materials with strongly correlated electrons often exhibit interesting physical properties. An example of these materials is the layered oxide perovskite Sr₂RuO₄, which has been intensively investigated due to its unusual properties. Whilst the debate on the symmetry of the superconducting state in Sr₂RuO₄ is still ongoing, a deeper understanding of the Sr₂RuO₄ normal state appears crucial as this is the background in which electron pairing occurs. Here, by using low-energy muon spin spectroscopy we discover the existence of surface magnetism in Sr₂RuO₄ in its normal state. We detect static weak dipolar fields yet manifesting at an onset temperature higher than 50 K. We ascribe this unconventional magnetism to orbital loop currents forming at the reconstructed Sr₂RuO₄ surface. Our observations set a reference for the discovery of the same magnetic phase in other materials and unveil an electronic ordering mechanism that can influence electron pairing with broken time reversal symmetry.

Genomic Action of Sigma-1 Receptor Chaperone Relates to Neuropathic Pain

Sigma-1 receptors (Sig-1Rs) are endoplasmic reticulum (ER) chaperones implicated in neuropathic pain. Here we examine if the Sig-1R may relate to neuropathic pain at the level of dorsal root ganglia (DRG). We focus on the neuronal excitability of DRG in a "spare nerve injury" (SNI) model of neuropathic pain in rats and find that Sig-1Rs likely contribute to the genesis of DRG neuronal excitability by decreasing the protein level of voltage-gated Cav2.2 as a translational inhibitor of mRNA. Specifically, during SNI, Sig-1Rs translocate from ER to the nuclear envelope via a trafficking protein Sec61β. At the nucleus, the Sig-1R interacts with cFos and binds to the promoter of 4E-BP1, leading to an upregulation of 4E-BP1 that binds and prevents eIF4E from initiating the mRNA translation for Cav2.2. Interestingly, in Sig-1R knockout HEK cells, Cav2.2 is upregulated. In accordance with those findings, we find that intra-DRG injection of Sig-1R agonist (+)pentazocine increases frequency of action potentials via regulation of voltage-gated Ca2+ channels. Conversely, intra-DRG injection of Sig-1R antagonist BD1047 attenuates neuropathic pain. Hence, we discover that the Sig-1R chaperone causes neuropathic pain indirectly as a translational inhibitor.

Glomerular hyperfiltration with hyperglycemia in the spontaneously diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model

Glomerular hyperfiltration is observed in an early stage of kidney diseases including diabetic nephropathy. A better understanding of pathophysiological changes in glomerular hyperfiltration is essential for development of new therapies to prevent kidney disease progression. In this study, we investigated glomerular changes including glomerular filtration rate (GFR) and glomerular size in the Spontaneously Diabetic Torii (SDT) fatty rat, an obese type 2 diabetic model, and we also evaluated pharmacological effects of the sodium glucose cotransporter 2 inhibitor dapagliflozin on the renal lesions. Dapagliflozin was administered to SDT fatty rats from 5 to 17 weeks of age. Blood and urinary biochemical parameters were periodically measured. GFR was determined by transdermal GFR monitor at 16 weeks of age and histopathological analysis was performed at 17 weeks of age. SDT fatty rat developed severe hyperglycemia and exhibited pathophysiological abnormalities in the kidney, such as an increased GFR, glomerular hypertrophy and tissue lesions. Dapagliflozin achieved good glycemic control during the experimental period, inhibited the increase in GFR, and improved histopathological abnormalities in tubules. These results suggest that the SDT fatty rat is a useful model for analyzing the pathogenesis of diabetic nephropathy during its early stage and dapagliflozin improves not only hyperglycemia but also glomerular hyperfiltration and tubule lesions in SDT fatty rat.

Messenger RNA expression and localization of xenin in the gastrointestinal tract in sheep

The present study aimed to determine the primary sequence of ovine xenin and clarify the mRNA expression and peptide localization of xenin in the gastrointestinal tract in sheep. The colocalization of xenin and glucose-dependent insulinotropic polypeptide was also compared in the antrum and duodenum. Analysis of the nucleotide sequence of ovine xenin revealed a high degree (97.9%) of sequence homology of the sequence between sheep and cattle, and the amino acids sequence determined for ovine xenin coincided (100%) with that of other mammalian species. Real-time quantitative PCR for ovine xenin did not show regional difference in the mRNA expression ratio of xenin. In contrast to the real-time quantitative PCR results, anti-xenin positive cells were abundantly localized in the abomasal antrum (P < 0.01) and at a lesser amount in the duodenum, but no antixenin positive cells were observed in the other regions. Anti-xenin single-positive cells were in a majority in the abomasal antrum, whereas anti-xenin single-positive cells, and anti-GIP single-positive cells, and double-positive cells were even colocalized in the duodenum. These results suggest that abomasal antrum is a major source of xenin in the ovine gastrointestinal tract.

Higher levels of social and material deprivation are associated with higher rates of influenza-like illness-related emergency department visits: Edmonton, Alberta, 2004-2014

OBJECTIVES

Neighbourhood-level deprivation is associated with hospitalization related to respiratory infections; however, hospitalizations exclude many who seek care with less severe respiratory illnesses. Another major seasonal contributor to respiratory illness-associated healthcare burdens are influenza-like illness (ILI)-related emergency department (ED) visits. We investigated associations between area-level social and material deprivation and ILI-related ED use.

STUDY DESIGN

This is a retrospective ecological study.

METHODS

We linked ILI-related ED visit data (2004-2014) for Edmonton, Alberta to a Canadian area-level material and social deprivation index, categorizing deprivation into quintiles. Using a multivariable Poisson model with log population as the offset, we modelled the relationship between visit rates and material and social deprivation adjusting for week and season, age, sex and the interaction between age and sex.

RESULTS

We included 67,585 ILI-related ED visits, representing 1075.5 (95% confidence interval (CI) = 1067.4-1083.6) visits per 100,000 person-years. ILI-related visit rates increased as each of material and social deprivation increased; increases were slightly greater for material deprivation. Comparing the most deprived quintile to the least deprived quintile: for material deprivation, ILI-related ED visit rates were two times higher (rate ratio (RR) = 2.00, 95% CI = 1.96-2.05); and, for social deprivation, one-and-a-half times higher (RR = 1.47, 95% CI = 1.44-1.51).

CONCLUSIONS

Higher area-level material and social deprivation were associated with higher ILI-related ED visit rates. These findings can be used to identify areas that may need additional public health and healthcare resources and to improve targeting of prevention strategies. Understanding differentials in healthcare use such as this may be especially relevant to ensuring equity of outcomes for pandemic preparedness planning.

Cocaine-induced endocannabinoid signaling mediated by sigma-1 receptors and extracellular vesicle secretion

Cocaine is an addictive drug that acts in brain reward areas. Recent evidence suggests that cocaine stimulates synthesis of the endocannabinoid 2-arachidonoylglycerol (2-AG) in midbrain, increasing dopamine neuron activity via disinhibition. Although a mechanism for cocaine-stimulated 2-AG synthesis is known, our understanding of 2-AG release is limited. In NG108 cells and mouse midbrain tissue, we find that 2-AG is localized in non-synaptic extracellular vesicles (EVs) that are secreted in the presence of cocaine via interaction with the chaperone protein sigma-1 receptor (Sig-1R). The release of EVs occurs when cocaine causes dissociation of the Sig-1R from ADP-ribosylation factor (ARF6), a G-protein regulating EV trafficking, leading to activation of myosin light chain kinase (MLCK). Blockade of Sig-1R function, or inhibition of ARF6 or MLCK also prevented cocaine-induced EV release and cocaine-stimulated 2-AG-modulation of inhibitory synapses in DA neurons. Our results implicate the Sig-1R-ARF6 complex in control of EV release and demonstrate that cocaine-mediated 2-AG release can occur via EVs.

Long-term crude probabilities of death among breast cancer patients by age and stage: a population-based survival study in Northeastern Spain (Girona-Tarragona 1985-2004)

Background

We provide population-based long-term survival indicators of breast cancer patients by quantifying the observed survival, and the probabilities of death due to breast cancer and to other causes by age and tumor stage at diagnosis.

Methods

We included a total of 10,195 female patients diagnosed before 85 years with invasive primary breast cancer in Girona and Tarragona during the periods 1985–1994 and 1995–2004 and followed-up until December 31st 2014. The survival indicators were estimated at 5, 10, 15 and 20 years of follow-up comparing diagnostic periods.

Results

Comparing diagnostic periods: I) the probability of death due to other causes did not change; II) the 20-year survival for women diagnosed ≤ 49 years increased 13% (1995–2004 = 68%; 1985–1994:55%), whereas their probability of death due to breast cancer decreased at the same pace (1995–2004 = 29%; 1985–1994 = 42%); III) at 10 years of follow-up, decreases in the probabilities of death due to breast cancer across age groups switched from 11 to 17% resulting in a risk of death reduction of 19% after adjusting by stage. During 1995–2004, the stage-specific 10-year probabilities of death due to breast cancer switched from: 3–6% in stage I, 18–20% in stage II, 34–46% in stage III and surpassed 70% in stage IV beyond 5 years after diagnosis.

Conclusions

In our study, women diagnosed with breast cancer had higher long-term probability to die from breast cancer than from other causes. The improvements in treatment and the lead-time bias in detecting cancer in an early stage resulted in a reduction of 19% in the risk of death between diagnostic periods.

Electronic supplementary material

The online version of this article (10.1007/s12094-018-1852-1) contains supplementary material, which is available to authorized users.

Synovial mesenchymal stem cells from osteo- or rheumatoid arthritis joints exhibit good potential for cartilage repair using a scaffold-free tissue engineering approach

OBJECTIVE

To assess whether synovial mesenchymal stem cells (SMSCs) from patients with osteoarthritis (OA) or rheumatoid arthritis (RA) can be used as an alternative cell source for cartilage repair using allogenic tissue engineered construct (TEC).

METHODS

Twenty-five patients (17 female, average age 61.8 years) were divided according to their pathology (control trauma group; N = 6, OA group; N = 6) and RA patients were subdivided into two groups to evaluate the impact of biologics in accordance with whether treated with biologics [Bio(+)RA; N = 7] or not [Bio(-)RA; N = 6]. We compared the following characteristics among these groups: (1) The cell proliferation capacity of SMSCs; (2) The influence of passage number on features of SMSCs; (3) The weight and volume of TEC from the same number of SMSCs; (4) Inflammatory cytokine gene expressions levels of TEC; (5) The chondrogenic potential of TEC; and (6) Osteochondral repair using TEC in athymic nude rats.

RESULTS

SMSCs from the four groups exhibited equivalent features in the above evaluation items. In in vivo studies, the TEC-treated repair tissues for all groups exhibited significantly better outcomes than those for the untreated group and no significant differences among the four TEC groups.

CONCLUSION

SMSCs from OA or RA patients are no less appropriate for repairing cartilage than those from trauma patients and thus, may be an effective source for allogenic cell-based cartilage repair.

Anatomy of the inferior extensor retinaculum and its role in lateral ankle ligament reconstruction: a pictorial essay

The inferior extensor retinaculum (IER) is an aponeurotic structure, which is in continuation with the anterior part of the sural fascia. The IER has often been used to augment the reconstruction of the lateral ankle ligaments, for instance in the Broström-Gould procedure, with good outcomes reported. However, its anatomy has not been described in detail and only a few studies are available on this structure. The presence of a non-constant oblique supero-lateral band appears to be important. This structure defines whether the augmentation of the lateral ankle ligaments reconstruction is performed using true IER or only the anterior part of the sural fascia. It is concluded that the use of this structure will have an impact on the resulting ankle stability.

Potential Molecular Mechanisms on the Role of the Sigma-1 Receptor in the Action of Cocaine and Methamphetamine

The sigma-1 receptor (Sig-1R) is an endoplasmic reticulum membrane protein that involves a wide range of physiological functions. The Sig-1R has been shown to bind psychostimulants including cocaine and methamphetamine (METH) and thus has been implicated in the actions of those psychostimulants. For example, it has been demonstrated that the Sig-1R antagonists mitigate certain behavioral and cellular effects of psychostimulants including hyperactivity and neurotoxicity. Thus, the Sig-1R has become a potential therapeutic target of medication development against drug abuse that differs from traditional monoamine-related strategies. In this review, we will focus on the molecular mechanisms of the Sig-1R and discuss in such a manner with a hope to further understand or unveil unexplored relations between the Sig-1R and the actions of cocaine and METH, particularly in the context of cellular biological relevance.

Survival in stage I-III breast cancer patients by surgical treatment in a publicly funded health care system

BACKGROUND

Recent investigations of breast cancer survival in the United States suggest that patients who receive mastectomy have poorer survival than those who receive breast-conserving surgery (BCS) plus radiotherapy, despite clinically established equivalence. This study investigates breast cancer survival in the publicly funded health care system present in Alberta, Canada.

PATIENTS AND METHODS

Surgically treated stage I-III breast cancer cases diagnosed in Alberta from 2002 to 2010 were included. Demographic, treatment and mortality information were collected from the Alberta Cancer Registry. Unadjusted overall and breast cancer-specific mortality was assessed using Kaplan-Meier and cumulative incidence curves, respectively. Cox proportional hazards models were used to calculate stage-specific mortality hazard estimates associated with surgical treatment received.

RESULTS

A total of 14 939 cases of breast cancer (14 633 patients) were included in this study. The unadjusted 5-year all-cause survival probabilities for patients treated with BCS plus radiotherapy, mastectomy, and BCS alone were 94% (95% CI 93% to 95%), 83% (95% CI 82% to 84%) and 74% (95% CI 70% to 78%), respectively. Stage II and III patients who received mastectomy had a higher all-cause (stage II HR = 1.36, 95% CI 1.13-1.48; stage III HR = 1.74, 95% CI 1.24-2.45) and breast cancer-specific (stage II HR = 1.39, 95% CI 1.09-1.76; stage III HR = 1.79, 95% CI 1.21-2.65) mortality hazard compared with those who received BCS plus radiotherapy, adjusting for patient and clinical characteristics. BCS alone was consistently associated with poor survival.

CONCLUSIONS

Stage II and III breast cancer patients diagnosed in Alberta, Canada, who received mastectomy had a significantly higher all-cause and breast cancer-specific mortality hazard compared with those who received BCS plus radiotherapy. We suggest greater efforts toward educating and encouraging patients to receive BCS plus radiotherapy rather than mastectomy when it is medically feasible and appropriate.

Abstract P4-08-01: Effects of exercise during adjuvant chemotherapy on clinical outcomes in early stage breast cancer

Background: Observational studies suggest that physical activity following a diagnosis of breast cancer may be associated with a lower risk of recurrence and death. Some studies also suggest possible effect modification by disease stage, body mass index, and receptor status. To date, however, there are no randomized trials examining the effects of exercise on disease outcomes in any cancer patient group. Here, we report an exploratory follow-up of disease outcomes from the Supervised Trial of Aerobic versus Resistance Training (START). Patients and Methods: The START Trial was a Canadian multicenter trial that randomized 242 breast cancer patients starting adjuvant chemotherapy to either usual care (n = 82) or supervised aerobic (n = 78) or resistance (n = 82) exercise for the duration of their chemotherapy. The primary efficacy endpoint for this exploratory analysis was disease-free survival (DFS). Secondary endpoints were overall survival (OS), distant disease-free survival (DDFS), and recurrence-free interval (RFI). The two exercise arms were combined for the analysis (n = 160) and selected subgroups were explored. Results: After a median follow-up of 89 months (IQR 81 to 96), there were 25/160 (15.6%) DFS events in the exercise groups and 18/82 (22.0%) in the control group (log-rank p = 0.21). Eight-year DFS was 82.7% for the exercise groups compared with 75.6% for the control group (Hazard ratio [HR] = 0.68, 95% CI = 0.37-1.24). There were 13/160 (8.1%) deaths in the exercise groups and 11/82 (13.4%) in the control group (log-rank p = 0.21). Eight-year OS was 91.2% in the exercise groups compared with 82.7% in the control group (HR = 0.60, 95% CI = 0.27 to 1.33. There were 20/160 (12.5%) DDFS events in the exercise groups and 16/82 (19.5%) in the control group (log-rank p = 0.15). Eight-year DDFS was 86.7% in the exercise groups compared with 78.3% in the control group (HR = 0.62, 95% CI = 0.32 to 1.19). Finally, there were 20/160 (12.5%) RFI events in the exercise groups and 17/82 (20.7%) in the control group (Gray's p = 0.095). Eight-year cumulative incidence of RFI was 12.6% in the exercise groups compared with 21.6% in the control group (HR = 0.58, 95% CI = 0.30 to 1.11). Subgroup analyses for DFS and RFI suggested stronger effects for women who were overweight/obese, had stage II/III cancer, receptor positive tumors, HER2 positive tumors, received taxane-based chemotherapies, and received at least 85% of their intended chemotherapy dose-intensity. The most notable subgroup effect was for patients who received optimal chemotherapy dosing with a borderline significant effect for DFS (HR = 0.50, 95% CI = 0.25 to 1.01) and a significant effect for RFI (HR = 0.38, 95% CI = 0.18 to 0.81). Conclusions: In this exploratory follow-up of the START Trial, there was a suggestion that exercise during adjuvant chemotherapy may improve several efficacy endpoints although none achieved statistical significance. Nevertheless, the magnitude of the effects appear to be meaningful with absolute 8-year survival differences between 7% and 9% and relative rate reductions between 30% and 40%. The START Trial provides the first randomized data to suggest that adding exercise to standard chemotherapy for breast cancer may improve outcomes. A definitive phase III trial is warranted.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-08-01.

Noninvasive estimation of fibrosis progression overtime using the FIB-4 index in chronic hepatitis C

The FIB-4 index is a simple formula to predict liver fibrosis based on the standard biochemical values (AST, ALT and platelet count) and age. We here investigated the utility of the index for noninvasive prediction of progression in liver fibrosis. The time-course alteration in the liver fibrosis stage between paired liver biopsies and the FIB-4 index was examined in 314 patients with chronic hepatitis C. The average interval between liver biopsies was 4.9 years. The cases that showed a time-course improvement in the fibrosis stage exhibited a decrease in the FIB-4 index, and those that showed deterioration in the fibrosis stage exhibited an increase in the FIB-4 index with a significant correlation (P < 0.001). Increase in the ΔFIB-4 index per year was an independent predictive factor for the progression in liver fibrosis with an odds ratio of 3.90 (P = 0.03). The area under the receiver operating characteristic curve of the ΔFIB-4 index/year for the prediction of advancement to cirrhosis was 0.910. Using a cut-off value of the ΔFIB-4 index/year <0.4 or ≥ 0.4, the cumulative incidence of fibrosis progression to cirrhosis at 5 and 10 years was 34% and 59%, respectively in patients with the ΔFIB-4 index/year ≥0.4, whereas it was 0% and 3% in those with the ΔFIB-4 index/year <0.4 (P < 0.001). In conclusion, measurement of the time-course changes in the FIB-4 index is useful for the noninvasive and real-time estimation of the progression in liver fibrosis.

The `genetic benefits' of female multiple mating reconsidered

In many animals, males can generally increase their fitness by mating with many mates, but females cannot produce more offspring than the number of their eggs. In spite of this restriction, females often mate with more than one male. In species without any male-provided resource benefits, females are thought to obtain some `genetic benefits' from males that enhance offspring quality. The evolution of female multiple mating is often confused with the issue of female mate choice, but mate choice is actually possible in the single-mating situation. Therefore, we still need to explain the possible advantage of multiple mating over single mating.

PMA-induced GCMa phosphorylation stimulates its transcriptional activity and degradation

Glial cells missing Drosophila homolog a (GCMa) is a member of the GCM transcription factor family and plays critical roles in trophoblast differentiation and placental functions. It is well established that the cyclic AMP (cAMP)-dependent pathway induces the expression and transcriptional activity of GCMa by regulating post-translational modifications of GCMa, which results in enhancement of trophoblast differentiation. We previously observed that phorbol 12-myristate 13-acetate (PMA) stimulates phosphorylation of GCMa on serines 328, 378 and 383 through the protein kinase C (PKC)- and mitogen-activated protein kinase kinase (MEK)/extracellular signalregulated kinase (ERK)-dependent pathway, which decreases the protein stability of GCMa. Here we report that PMA increases the ubiquitination level of GCMa, dependent on the phosphorylation of GCMa on serines 328, 378 and 383. We found that this phosphorylation also stimulates the transcriptional activity of GCMa. Our data indicate that the PMA-induced PKC- and MEK/ERKdependent pathway enhances the degradation as well as the transcriptional activity of GCMa. We also examined the impact of this signaling pathway on trophoblasts and the results suggest that the PKC- and MEK/ERK-dependent pathway is involved in the regulation of trophoblast differentiation.

Biochemical responses to dietary α-linolenic acid restriction proceed differently among brain regions in mice

Previously, we noted that the dietary restriction of α-linolenic acid (ALA, n-3) for 4 weeks after weaning brought about significant decreases in the BDNF content and p38 MAPK activity in the striatum of mice, but not in the other regions of the brain, compared with an ALA- and linoleic acid (LNA, n-6)-adequate diet. In this study, we examined whether a prolonged dietary manipulation induces biochemical changes in other regions of the brain as well. Mice were fed a safflower oil (SAF) diet (ALA-restricted, LNA-adequate) or a perilla oil (PER) diet (containing adequate amounts of ALA and LNA) for 8 weeks from weaning. The docosahexaenoic acid (DHA, 22:6n-3) contents and p38 MAPK activities in the cerebral cortex, striatum and hippocampus were significantly lower in the SAF group. The BDNF contents and protein kinase C (PKC) activities in the cerebral cortex as well as in the striatum, but not in the hippocampus, were significantly lower in the SAF group. These data indicate that the biochemical changes induced by the dietary restriction of ALA have a time lag in the striatum and cortex, suggesting that the signal is transmitted through decreased p38 MAPK activity and BDNF content and ultimately decreased PKC activity.

PMA induces GCMa phosphorylation and alters its stability via the PKC- and ERK-dependent pathway

The glial cells missing a (GCMa) transcription factor plays a pivotal role in the placental development by regulating the expression of several genes in the placenta that are responsible for the proper formation of the syncytiotrophoblast. It is well known that the function of GCMa is regulated at both transcriptional and post-translational levels by the cyclic AMP (cAMP)/protein kinase A (PKA)-dependent pathway, the activation of which increases the GCMa protein level and leads to trophoblast differentiation into the syncytiotrophoblast. However, little is known about the regulatory control of GCMa by PKC-dependent signaling mechanism(s). To investigate whether GCMa is regulated by PKC-dependent pathway, we treated the human choriocarcinoma JEG-3 cells with phorbol 12-myristate 13-acetate (PMA) and studied its effect on the GCMa protein using a monoclonal anti-GCMa antibody we prepared. PMA caused a transient decrease in the endogenous GCMa protein level in JEG-3 cells that was accompanied by an increase in GCMa phosphorylation. The phosphorylation and degradation of GCMa by PMA treatment was effectively reduced by pretreatment with protein kinase C (PKC) inhibitors and a mitogen-activated protein kinase (MAPK) kinase (MEK) inhibitor, indicating a PKC- and MEK-dependent mechanism. Furthermore, we identified the serine residues 328, 378 and 383 to be the phosphorylation sites on GCMa that are involved in the PMA-induced degradation of GCMa. Our data demonstrate for the first time that GCMa is phosphorylated by the PKC- and MEK/extracellular signal-regulated kinase (ERK)-dependent mechanism, and that this phosphorylation is involved in its degradation process.

Rates of initial virological suppression and subsequent virological failure after initiating highly active antiretroviral therapy: the impact of aboriginal ethnicity and injection drug use

Objectives:

To compare rates of initial virological suppression and subsequent virological failure by Aboriginal ethnicity after starting highly active antiretroviral therapy (HAART).

Methods:

We conducted a retrospective cohort study of antiretroviral-naïve HIV-patients starting HAART in January 1999-June 2005 (baseline), followed until December 31, 2005 in Alberta, Canada. We compared the odds of achieving initial virological suppression (viral load <500 copies/mL) by Aboriginal ethnicity using logistic regression and, among those achieving suppression, rates of virological failure (the first of two consecutive viral loads > 1000 copies/mL) by Aboriginal ethnicity using cumulative incidence curves and Cox proportional hazards models. Sex, injection drug use as an HIV exposure category (IDU), baseline age, CD4 cell count, viral load, calendar year, and HAART regimen were considered as potential confounders.

Results:

Of 461 study patients, 37% were Aboriginal and 48% were IDUs; 71% achieved initial virological suppression and were followed for 730.4 person-years. After adjusting for confounding variables, compared to non-Aboriginals with other exposures, the odds of achieving initial virological suppression were lower for Aboriginal IDUs (odds ratio (OR)=0.33, 95% CI=0.19-0.60, p=0.0002), non-Aboriginal IDUs (OR=0.30, 95% CI=0.15-0.60, p=0.0006), and Aboriginals with other exposures (OR=0.38, 95% CI=0.21-0.67, p=0.0009). Among those achieving suppression, Aboriginals experienced higher virological failure rates ≥1 year after suppression (hazard ratio=3.35, 95% CI=1.68-6.65, p=0.0006).

Conclusions:

Future research should investigate adherence among Aboriginals and IDUs treated with HAART and explore their treatment experiences to assess ways to improve outcomes.

Referral rate to oncologists and its variation by hospital for colorectal cancer patients

BACKGROUND

Recent population-based studies in Alberta, Canada, found that approximately 50% of patients with stage III colon or stages II/III rectal adenocarcinoma did not receive guideline-recommended treatment (surgery plus chemotherapy or chemoradiation); a primary reason was not having an oncologist consult. We assessed the relationship between the hospital where the surgery was performed and the probability of a patient not having an oncologist consult.

METHODS

All patients diagnosed with stage III colon or stage II/III rectal adenocarcinoma between 2002 and 2005 in Alberta who had surgery were identified from the Alberta Cancer Registry and included in the study. Multivariable logistic regression modeling with hospitals as random effects was used to estimate cancer-type-specific odds ratios of not having an oncologist consult for each hospital, adjusted for age, sex, and comorbidities, relative to the overall nonconsultation rate.

RESULTS

Overall, 21% of stage III colon, 25% of stage II rectal, and 13% of stage III rectal adenocarcinoma patients did not have an oncologist consult. Rates varied appreciably across hospitals and between cancer types within hospitals, even after the case-mix adjustment (adjusted odds ratios of nonconsultation ranged from 0.4 to 8.1). Small hospitals that performed 12 or fewer surgeries had nearly 100% consultation rates.

CONCLUSIONS

The variation in oncologist-consult rates, particularly for stage II rectal cancer patients, is concerning. We are presenting the findings to the surgical community and discussing interventions to improve oncologist-consult rates.

Development of novel rat model for high-fat and high-cholesterol diet-induced steatohepatitis and severe fibrosis progression in SHRSP5/Dmcr

OBJECTIVES

Patients with nonalcoholic fatty liver disease are increasing worldwide, and preventive measures are an urgent need and primary concern today.

AIM

This study aimed to develop and clarify the usefulness of the SHRSP5/Dmcr rat, derived from a stroke-prone spontaneously hypertensive rat, as a novel animal model for time-course analysis of steatohepatitis and the severe fibrosis progression often observed in the disease.

METHODS

Ten-week-old male SHRSP5/Dmcr rats were divided into six groups: half were fed a high-fat and high-cholesterol-containing diet (HFC diet), and the others the control, stroke-prone (SP) diet for 2, 8, and 14 weeks.

RESULTS

The HFC diet significantly increased serum transaminase and gamma glutamyl transpeptidase activities, tumor necrosis factor alpha levels, and serum and hepatic total cholesterol levels over time. In contrast, this diet decreased serum albumin, glucose, and adiponectin levels throughout or the later stage of the feeding period, but did not influence serum insulin levels. Histopathologically, the HFC diet increased microvesicular steatosis, and focal or spotty necrosis with lymphocyte infiltrations were observed in the liver at 2 weeks, macrovesicular steatosis, ballooned hepatocytes with Mallory-Denk body formation in some, and multilobular necrosis and fibrosis at 8 weeks. Interestingly, this fibrosis formed a honeycomb network at 14 weeks. These changes are very similar to those observed in patients with non-alcoholic steatohepatitis.

CONCLUSIONS

SHRSP5/Dmcr rats appear to be a useful model for analyzing the time-dependent changes of HFC diet-induced steatohepatitis and fibrosis progression.

Adherence to treatment guidelines in stage II/III rectal cancer in Alberta, Canada

AIMS

Evidence suggests that pre- and/or postoperative treatment benefits patients with stage II/III rectal cancer. This study aimed to quantify treatment patterns and adherence to treatment guidelines, and to identify barriers to having a consultation with an oncologist and barriers to receiving treatment in stage II/III rectal cancer, in a publicly funded medical care system.

MATERIALS AND METHODS

Patients with surgically treated stage II/III rectal adenocarcinoma, diagnosed from 2002 to 2005 in Alberta, a Canadian province with a population of 3 million, were included. Demographic and treatment information from the Alberta Cancer Registry were linked to data from electronic medical records, hospital discharge data and the 2001 Canadian Census. The study outcomes were 'not having an oncologist consultation' and 'not receiving guideline-based treatment'. The relative risks of the two outcomes in association with patient characteristics were estimated using multivariable log-binomial regression.

RESULTS

Of a total of 910 surgically treated stage II/III rectal adenocarcinoma patients, 748 (82%) had a consultation with an oncologist and 414 (45.5%) received treatment. Pre-/post-surgical treatment modalities and timing varied; 96 (10.5%) received neoadjuvant treatment only, 389 (42.7%) received adjuvant treatment only, 119 (13.1%) received both, and 306 (33.6%) had surgery alone. Factors related to not having a consultation with an oncologist included older age, co-morbidities, cancer stage II and region of residence. Older age was the most significantly associated factor with not receiving treatment (relative risk=2.23; 95% confidence interval: 1.89, 2.64).

CONCLUSIONS

Disparities exist in the receipt of treatment in stage II/III rectal cancer. Factors such as age, region of residence and stage should not be barriers to consulting an oncologist to discuss or receive treatment. The reasons for these disparities need to be identified and addressed.

Testosterone-lowering activity of canola and hydrogenated soybean oil in the stroke-prone spontaneously hypertensive rat

Canola and some other types of oil unusually shorten the survival of stroke-prone spontaneously hypertensive rats (SHRSP), compared with soybean oil, perilla oil and animal fats. Since differential effects of canola and soybean oil on steroid hormone metabolism were suggested by a preliminary DNA microarray analysis as a reason for this, the steroid hormone levels in the serum and tissues of SHRSP fed different oils were investigated. The testosterone levels in the serum and the testes were found to be significantly lower in the canola oil group than in the soybean oil group, while no significant differences were detected in the corticosterone and estradiol levels in tissues. In a second experiment, it was found that hydrogenated soybean oil, with a survival-shortening activity comparable to that of canola oil, also decreased the testosterone level in testes to a similar degree. The testosterone-lowering activity of canola and hydrogenated soybean oil observed in SHRSP was considered in relation to other factors possibly affecting the physiology of SHRSP.

Glucose-lowering agents and cancer mortality rates in type 2 diabetes: assessing effects of time-varying exposure

AIMS/HYPOTHESIS

We explored the relationship between glucose-lowering agents and cancer mortality rates in type 2 diabetes patients, hypothesising a decreased risk of cancer mortality with metformin use and a dose-risk gradient for insulin therapy.

METHODS

This was a population-based cohort study using administrative data from Saskatchewan Health, Canada. We identified new users of metformin or sulfonylureas from 1 January 1991 to 31 December 1996, with follow-up until death, departure from the province or 31 December 1999. Cox regression analyses were used to estimate the HR of death from cancer, accounting for time-varying exposure to metformin, sulfonylurea, and exogenous insulin therapy.

RESULTS

We identified 10,309 new users of metformin or sulfonylurea. The average follow-up was 5.4 (1.9) years, during which 407 (4.0%) cancer deaths occurred. Adjusting for age, sex and chronic disease score, the adjusted HR for metformin use was 0.80 (95% CI 0.65-0.98) compared with sulfonylurea monotherapy users. Adjusted HRs for subsequent insulin use were 2.22 (0.99-5.00), 3.33 (2.26-4.89) and 6.40 (4.69-8.73) for <3, 3 to 11 and > or = 12 insulin dispensations/year, respectively, compared with patients not on insulin. We observed a similar risk gradient among the sub-cohort of new insulin users.

CONCLUSIONS/INTERPRETATION

Our results support previous reports of a decreased risk of cancer outcomes associated with metformin use relative to sulfonylurea monotherapy. We also provide new evidence of a gradient of cumulative insulin dispensations and cancer mortality rates.

Clinical features of cases of influenza A (H1N1)v in Osaka prefecture, Japan, May 2009

This report describes the clinical characteristics of influenza A(H1N1)v virus infection in Osaka. By the end of May, 171 cases had been reported in Osaka. Most patients were from one school. No patient had a serious underlying medical condition.Clinical symptoms were mild and resembled those of seasonal influenza. The sensitivity of the rapid antigen test was 77%. Antivirals were given to the majority of the cases. Early antiviral treatment may have shortened the duration of fever.

Epidemiology of influenza A(H1N1)v virus infection in Japan, May - June 2009

Between 9 May and 4 June 2009, a total of 401 laboratory-confirmed cases of influenza A(H1N1)v virus were reported in Japan, from 16 of the 47 Japanese prefectures. The two areas most affected were Osaka prefecture and Kobe city where outbreaks in high schools occurred leading to school closures. To date all cases have had symptoms consistent with seasonal influenza and no severe or fatal cases have been reported.

The virtues of a deliberately mis-specified disease model in demonstrating a gene-environment interaction

OBJECTIVES

This study seeks to assess the impact of measurement errors in cumulative exposure on estimates of a gene-environment interaction in a nested case-control study in occupational epidemiology. In the approach considered here, exposure intensity is assessed at the group level and the exposure duration individually (both with error). Genetic susceptibility is assumed to be known exactly. Differences in "gene" are assumed to affect disease risk only in exposed subjects.

METHODS

Three data analysis strategies were considered: one using a correctly specified disease model (exposure and exposure-gene interaction), and two using mis-specified disease models, one with "gene" as the only risk factor ("gene-only" model) and the other with main effects of both gene and exposure along with their interaction ("full" model).

RESULTS

In simulations, estimates of the gene-environment interaction based on the correctly specified disease model were greatly attenuated and power was diminished appreciably even when errors in exposure were modest. Significant associations were detected more frequently in the gene-only model when errors in exposure were large. When the "full" mis-specified model was fitted to the simulated data, it yielded erratic estimates. This is illustrated in an analysis of the interaction of cumulative exposure to organophosphate pesticides and paraoxonase gene on the risk of chronic neuropsychological effects among farmers who dip sheep.

CONCLUSION

If "gene" contributes to disease risk only in the presence of exposure, the existence of the gene-environment interaction can be efficiently inferred from a deliberately mis-specified "gene-only" disease model in nested case-control studies.