BACKGROUND:Continuous positive airway pressure (CPAP) has failed to reduce cardiovascular risk in obstructive sleep apnoea (OSA) in randomized trials. CPAP increases angiopoietin-2, a lung distension-responsive endothelial proinflammatory marker associated with increased cardiovascular risk. We investigated whether CPAP has unanticipated proinflammatory effects in patients with OSA and cardiovascular disease.METHODS:Patients with OSA (apnoea-hypopnea index [AHI] ≥15 events/h without excessive sleepiness) in the Randomized Intervention with CPAP in Coronary Artery Disease and OSA study were randomized to CPAP or usual care following coronary revascularization. Changes in plasma levels of biomarkers of endothelial (angiopoietin-2, Tie-2, E-selectin, vascular endothelial growth factor [VEGF-A]) and lung epithelial (soluble receptor of advanced glycation end-products [sRAGE]) function from baseline to 12-month follow-up were compared across groups and associations with cardiovascular morbidity and mortality assessed.FINDINGS:Patients with OSA (n = 189; 84% men; age 66 ± 8 years, BMI 28 ± 3.5 kg/m2, AHI 41 ± 23 events/h) and 91 patients without OSA participated. Angiopoietin-2 remained elevated whereas VEGF-A declined significantly over 12 months in the CPAP group (n = 91). In contrast, angiopoietin-2 significantly declined whereas VEGF-A remained elevated in the usual care (n = 98) and OSA-free groups. The changes in angiopoietin-2 and VEGF-A were significantly different between CPAP and usual care, whereas Tie-2, sRAGE and E-selectin were similar. Greater 12-month levels of angiopoietin-2 were associated with greater mortality. Greater CPAP levels were associated with worse cardiovascular outcomes.INTERPRETATION:Greater CPAP levels increase proinflammatory, lung distension-responsive angiopoietin-2 and reduce cardioprotective angiogenic factor VEGF-A compared to usual care, which may counteract the expected cardiovascular benefits of treating OSA.FUNDING:National Institutes of Health/National Heart, Lung, and Blood Institute; Swedish Research Council; Swedish Heart-Lung Foundation; ResMed Foundation.
Rationale: We recently demonstrated that patients with coronary artery disease (CAD) and obstructive sleep apnea (OSA) carrying the tumor necrosis factor-alpha (TNF-α) A allele had increased circulating TNF-α levels compared with the ones carrying the TNF-α G allele. In the current study, we addressed the effect of TNF-α (-308G/A) gene polymorphism on circulating TNF-α levels following continuous positive airway pressure (CPAP) therapy. Methods: This study was a secondary analysis of the RICCADSA trial (NCT00519597) conducted in Sweden. CAD patients with OSA (apnea–hypopnea index) of ≥15 events/h and an Epworth Sleepiness Scale (ESS) score of <10 were randomized to CPAP or no-CPAP groups, and OSA patients with an ESS score of ≥10 were offered CPAP treatment. Blood samples were obtained at baseline and 12-month follow-up visits. TNF-α was measured by immunoassay (Luminex, R&D Systems). Genotyping of TNF-α-308G/A (single nucleotide polymorphism Rs1800629) was performed by polymerase chain reaction–restriction fragment length polymorphism. Results: In all, 239 participants (206 men and 33 women; mean age 64.9 (SD 7.7) years) with polymorphism data and circulating levels of TNF-α at baseline and 1-year follow-up visits were included. The median circulating TNF-α values fell in both groups between baseline and 12 months with no significant within- or between-group differences. In a multivariate linear regression model, a significant change in circulating TNF-α levels from baseline across the genotypes from GA to GA and GA to AA (standardized β-coefficient −0.129, 95% confidence interval (CI) −1.82; −0.12; p = 0.025) was observed in the entire cohort. The association was more pronounced among the individuals who were using the device for at least 4 h/night (n = 86; standardized β-coefficient −2.979 (95% CI −6.11; −1.21); p = 0.004)), whereas no significant association was found among the patients who were non-adherent or randomized to no-CPAP. The participants carrying the TNF-α A allele were less responsive to CPAP treatment regarding the decline in circulating TNF-α despite CPAP adherence (standardized β-coefficient −0.212, (95% CI −5.66; −1.01); p = 0.005). Conclusions: Our results suggest that TNF-α (-308G/A) gene polymorphism is associated with changes in circulating TNF-α levels in response to CPAP treatment in adults with CAD and OSA.
Background: Increased levels of Vascular Endothelial Growth Factor-A (VEGF-A) are associated with obstructive sleep apnoea (OSA). While VEGF-A is an important mediator of vascular repair in response to local hypoxemia, its overexpression in response to generalized hypoxemia may contribute to vascular disease. It is unclear whether continuous positive airway pressure (CPAP) treatment influences VEGF-A levels in patients with coronary artery disease (CAD) and OSA. Objectives: To evaluate whether CPAP therapy would reduce VEGF-A after 1 year in a revascularized CAD cohort. Methods: OSA patients from the RICCADSA cohort with an AHI ≥15/h and Epworth Sleepiness Scale <10 were randomized to CPAP (n=92) or no-CPAP (n=98). Blood samples were obtained at baseline and 1 year follow-up. VEGF-A was measured by immunoassay (Luminex). Results: Mean CPAP adherence was 3.2±2.8 h/night. CPAP reduced VEGF-A levels compared with controls (table 1).). In a linear regression analysis, allocation to CPAP was associated with the magnitude of change in VEGF-A after adjusting for age, sex, BMI, and baseline VEGF-A (standardized β=0.05 [95%CI, 0.001-0.105], p= 0.047). These changes were greater in patients using CPAP≥4 h/night. Conclusions: CPAP reduces VEGF-A levels in OSA patients after coronary revascularization. The implication of this change for cardiovascular health is unknown.
Obstructive sleep apnea (OSA) is common in patients with coronary artery disease (CAD), in which inflammatory activity has a crucial role. The manifestation of OSA varies significantly between individuals in clinical cohorts; not all adults with OSA demonstrate the same set of symptoms; i.e., excessive daytime sleepiness (EDS) and/or increased levels of inflammatory biomarkers. The further exploration of the molecular basis of these differences is therefore essential for a better understanding of the OSA phenotypes in cardiac patients. In this current secondary analysis of the Randomized Intervention with Continuous Positive Airway Pressure in CAD and OSA (RICCADSA) trial (Trial Registry: ClinicalTrials.gov; No: NCT 00519597), we aimed to address the association of tumor necrosis factor alpha (TNF-α)-308G/A gene polymorphism with circulating TNF-α levels and EDS among 326 participants. CAD patients with OSA (apnea–hypopnea-index (AHI) ≥ 15 events/h; n = 256) were categorized as having EDS (n = 100) or no-EDS (n = 156) based on the Epworth Sleepiness Scale score with a cut-off of 10. CAD patients with no-OSA (AHI < 5 events/h; n = 70) were included as a control group. The results demonstrated no significant differences regarding the distribution of the TNF-α alleles and genotypes between CAD patients with vs. without OSA. In a multivariate analysis, the oxygen desaturation index and TNF-α genotypes from GG to GA and GA to AA as well as the TNF-α-308A allele carriage were significantly associated with the circulating TNF-α levels. Moreover, the TNF-α-308A allele was associated with a decreased risk for EDS (odds ratio 0.64, 95% confidence interval 0.41–0.99; p = 0.043) independent of age, sex, obesity, OSA severity and the circulating TNF-α levels. We conclude that the TNF-α-308A allele appears to modulate circulatory TNF-α levels and mitigate EDS in adults with CAD and concomitant OSA.
Myosin-1C (MYO1C) is a tumor suppressor candidate located in a region of recurrent losses distal to TP53. Myo1c can tightly and specifically bind to PIP2, the substrate of Phosphoinositide 3-kinase (PI3K), and to Rictor, suggesting a role for MYO1C in the PI3K pathway. This study was designed to examine MYO1C expression status in a panel of well-stratified endometrial carcinomas as well as to assess the biological significance of MYO1C as a tumor suppressor in vitro. We found a significant correlation between the tumor stage and lowered expression of MYO1C in endometrial carcinoma samples. In cell transfection experiments, we found a negative correlation between MYO1C expression and cell proliferation, and MYO1C silencing resulted in diminished cell migration and adhesion. Cells expressing excess of MYO1C had low basal level of phosphorylated protein kinase B (PKB, a.k.a. AKT) and cells with knocked down MYO1C expression showed a quicker phosphorylated AKT (pAKT) response in reaction to serum stimulation. Taken together the present study gives further evidence for tumor suppressor activity of MYO1C and suggests MYO1C mediates its tumor suppressor function through inhibition of PI3K pathway and its involvement in loss of contact inhibition.
Abstract In the previous work, a minimal region of recurrent deletion distal to the Tp53 gene was identified in BDII rat model for endometrial adenocarcinoma and the MYO1C gene was singled out as the tumor suppressor candidate in this region. Myo1c can bind to PIP2, the substrate of PI3-kinase, as well as to the mTOR complex, indicating a role for MYO1C in the PI3-kinase pathway. In this study, we assessed protein levels of 12 members of PI3-kinase/AKT signaling pathways in transient transfected HeLa cells expressing increasing amounts of MYO1C using Western blotting and densitometry analyses. Results revealed decreased protein levels of PTEN, AKT, and phosphorylated AKT, at both residues T308 and S473, and an increased expression of p110α protein in the cells transfected with the MYO1C gene expression constructs compared to the control cells transfected with empty plasmid. We next investigated potential effect of MYO1C protein depletion on serum-induced activation (phosphorylation) of AKT in the MCF10A cells that has de novo expression of MYO1C protein. Following serum stimulation, AKT was rapidly phosphorylated in its residue S473 (pAKTS473) in the cells transfected with MYO1C-siRNA, but with significantly lesser extent in the control cells. Overall, a negative correlation between the protein expression of MYO1C and AKT expression/activation was suggested, signifying a role for MYO1C as a negative regulator of PI3-kinsase/AKT signaling pathway. This is in agreement with the initial hypothesis of involvement of MYO1C in tumorigenesis pathways through its potential tumor suppressor activity. Further studies are required to fully understand the functional contribution of MYO1C to tumor development. Citation Format: Kittichate Visuttijai, Katarina Ejeskär, Afrouz Behboudi. Analyses of protein expression of PI 3-kinase/AKT signaling in response to altered expression of motor protein MYO1C. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2166. doi:10.1158/1538-7445.AM2015-2166
BACKGROUND:Several reports indicate a commonly deleted chromosomal region independent from, and distal to the TP53 locus in a variety of human tumors. In a previous study, we reported a similar finding in a rat tumor model for endometrial carcinoma (EC) and through developing a deletion map, narrowed the candidate region to 700 kb, harboring 19 genes. In the present work real-time qPCR analysis, Western blot, semi-quantitative qPCR, sequencing, promoter methylation analysis, and epigenetic gene expression restoration analyses (5-aza-2'-deoxycytidine and/or trichostatin A treatments) were used to analyze the 19 genes located within the candidate region in a panel of experimental tumors compared to control samples.RESULTS:Real-time qPCR analysis suggested Hic1 (hypermethylated in cancer 1), Inpp5k (inositol polyphosphate-5-phosphatase K; a.k.a. Skip, skeletal muscle and kidney enriched inositol phosphatase) and Myo1c (myosin 1c) as the best targets for the observed deletions. No mutation in coding sequences of these genes was detected, hence the observed low expression levels suggest a haploinsufficient mode of function for these potential tumor suppressor genes. Both Inpp5k and Myo1c were down regulated at mRNA and/or protein levels, which could be rescued in gene expression restoration assays. This could not be shown for Hic1.CONCLUSION:Innp5k and Myo1c were identified as the best targets for the deletions in the region. INPP5K and MYO1C are located adjacent to each other within the reported independent region of tumor suppressor activity located at chromosome arm 17p distal to TP53 in human tumors. There is no earlier report on the potential tumor suppressor activity of INPP5K and MYO1C, however, overlapping roles in phosphoinositide (PI) 3-kinase/Akt signaling, known to be vital for the cell growth and survival, are reported for both. Moreover, there are reports on tumor suppressor activity of other members of the gene families that INPP5K and MYO1C belong to. Functional significance of these two candidate tumor suppressor genes in cancerogenesis pathways remains to be investigated.
Background Development of breast cancer is a multistage process influenced by hormonal and environmental factors as well as by genetic background. The search for genes underlying this malignancy has recently been highly productive, but the etiology behind this complex disease is still not understood. In studies using animal cancer models, heterogeneity of the genetic background and environmental factors is reduced and thus analysis and identification of genetic aberrations in tumors may become easier. To identify chromosomal regions potentially involved in the initiation and progression of mammary cancer, in the present work we subjected a subset of experimental mammary tumors to cytogenetic and molecular genetic analysis. Methods Mammary tumors were induced with DMBA (7,12-dimethylbenz[a]anthrazene) in female rats from the susceptible SPRD-Cu3 strain and from crosses and backcrosses between this strain and the resistant WKY strain. We first produced a general overview of chromosomal aberrations in the tumors using conventional kartyotyping (G-banding) and Comparative Genome Hybridization (CGH) analyses. Particular chromosomal changes were then analyzed in more details using an in-house developed BAC (bacterial artificial chromosome) CGH-array platform. Results Tumors appeared to be diploid by conventional karyotyping, however several sub-microscopic chromosome gains or losses in the tumor material were identified by BAC CGH-array analysis. An oncogenetic tree analysis based on the BAC CGH-array data suggested gain of rat chromosome (RNO) band 12q11, loss of RNO5q32 or RNO6q21 as the earliest events in the development of these mammary tumors. Conclusions Some of the identified changes appear to be more specific for DMBA-induced mammary tumors and some are similar to those previously reported in ACI rat model for estradiol-induced mammary tumors. The later group of changes is more interesting, since they may represent anomalies that involve genes with a critical role in mammary tumor development. Genetic changes identified in this work are at very small scales and thus may provide a more feasible basis for the identification of the target gene(s). Identification of the genes underlying these chromosome changes can provide new insights to the mechanisms of mammary carcinogenesis.
Endometrial adenocarcinoma (EAC) is the most common form of malignancy in the female genital tract, ranking as the fourth leading form of invasive tumors that affect women. The BDII inbred rat strain has been used as a powerful tumor model in studies of the genetic background of EAC. Females from the BDII strain are prone to develop tumors with an incidence of more than 90%. Development of EAC in BDII female rats has similarities in pathogenesis, histopathological, and molecular properties to that of human, and thus represents a unique model for analysis of EAC tumorigenesis and for comparative studies in human EACs. In a previous study, a set of rat EAC cell lines derived from tumors developed in female crossprogenies between BDII and nonsusceptible rat strains were analyzed by spectral karyotyping (SKY). Here we present an analysis with specific focus on the impact of different genetic backgrounds on the rate and occurrence of genetic aberrations in experimental tumors using data presented in the previous report. We could reveal that the ploidy state, and the abundance and type of structural as well as numerical change differed between the two genetic setups. We have also identified chromosomes harboring aberrations independent of genetic input from the nonsusceptible strains, which provide valuable information for the identification of the genes involved in the development of EAC in the BDII model as well as in human endometrial tumors. © 2012 Wiley Periodicals, Inc.
Review on CRTC1 (CREB regulated transcription coactivator 1), with data on DNA, on the protein encoded, and where the gene is implicated.
Review on Skin: Clear cell hidradenoma of the skin (CCH), with data on clinics, and the genes involved.
BACKGROUND:Genomic alterations are common features of cancer cells, and some of these changes are proven to be neoplastic-specific. Such alterations may serve as valuable tools for diagnosis and classification of tumors, prediction of clinical outcome, disease monitoring, and choice of therapy as well as for providing clues to the location of crucial cancer-related genes.Endometrial carcinoma (EC) is the most frequently diagnosed malignancy of the female genital tract, ranking fourth among all invasive tumors affecting women. Cytogenetic studies of human ECs have not produced very conclusive data, since many of these studies are based on karyotyping of limited number of cases and no really specific karyotypic changes have yet been identified. As the majority of the genes are conserved among mammals, the use of inbred animal model systems may serve as a tool for identification of underlying genes and pathways involved in tumorigenesis in humans. In the present work we used spectral karyotyping (SKY) to identify cancer-related aberrations in a well-characterized experimental model for spontaneous endometrial carcinoma in the BDII rat tumor model.RESULTS:Analysis of 21 experimental ECs revealed specific nonrandom numerical and structural chromosomal changes. The most recurrent numerical alterations were gains in rat chromosome 4 (RNO4) and losses in RNO15. The most commonly structural changes were mainly in form of chromosomal translocations and were detected in RNO3, RNO6, RNO10, RNO11, RNO12, and RNO20. Unbalanced chromosomal translocations involving RNO3p was the most commonly observed structural changes in this material followed by RNO11p and RNO10 translocations.CONCLUSION:The non-random nature of these events, as documented by their high frequencies of incidence, is suggesting for dynamic selection of these changes during experimental EC tumorigenesis and therefore for their potential contribution into development of this malignancy. Comparative molecular analysis of the identified genetic changes in this tumor model with those reported in the human ECs may provide new insights into underlying genetic changes involved in EC development and tumorigenesis.
Animal cancer models reduce genetic background heterogeneity and thus, may facilitate identification and analysis of specific genetic aberrations in tumor cells. Rat and human mammary glands have high similarity in physiology and show comparable hormone responsiveness. Thus, spontaneous and carcinogen (e.g., NMU and DMBA)‐induced rat mammary models are valuable tools for genetic studies of breast cancer. In NMU‐induced rat mammary tumors, activating mutations in Hras codon 12 have frequently been reported and are supposed to contribute to the mammary carcinogenic process. Involvement of Ras mutations in DMBA‐induced tumors is less clear. In the present study we investigated the mutation status of the three Ras genes, Hras , Kras , and Nras , in DMBA‐induced rat mammary tumors. We examined codons 12, 13, and 61 of all three genes for mutations in 71 tumors using direct sequencing method that in experimental conditions is sensitive enough to detect single nucleotide mutations even when present in only 25% of the test sample. No activating Ras gene mutation was found. Thus, in contrast to NMU‐induced rat mammary tumor, tumorigenesis in DMBA‐induced rat mammary tumors seems to be independent on activating mutations in the Ras genes. Our finding suggests that the genetic pathways selected in mammary tumor development are influenced by and perhaps dependent on the identity of the inducing agent, again emphasizing the importance of tumor etiology on the genetic changes in the tumor cells. © 2008 Wiley‐Liss, Inc.
Female rats of the BDII/Han inbred strain are prone to spontaneously develop endometrial carcinomas (EC) that in cell biology and pathogenesis are very similar to those of human. Human EC are classified into two major groups: Type I displays endometroid histology, is hormone-dependent, and characterized by frequent microsatellite instability and PTEN, K-RAS, and CTNNB1 (beta-Catenin) mutations; Type II shows non-endometrioid histology, is hormone-unrelated, displays recurrent TP53 mutation, CDKN2A (P16) inactivation, over-expression of ERBB2 (Her2/neu), and reduced CDH1 (Cadherin 1 or E-Cadherin) expression. However, many human EC have overlapping clinical, morphologic, immunohistochemical, and molecular features of types I and II. The EC developed in BDII rats can be related to type I tumors, since they are hormone-related and histologically from endometrioid type. Here, we combined gene sequencing (Pten, Ifr1, and Ctnnb1) and real-time gene expression analysis (Pten, Cdh1, P16, Erbb2, Ctnnb1, Tp53, and Irf1) to further characterize molecular alterations in this tumor model with respect to different subtypes of EC in humans. No mutation in Pten and Ctnnb1 was detected, whereas three tumors displayed sequence aberrations of the Irf1 gene. Significant down regulation of Pten, Cdh1, p16, Erbb2, and Ctnnb1 gene products was found in the tumors. In conclusion, our data suggest that molecular features of spontaneous EC in BDII rats can be related to higher-grade human type I tumors and thus, this model represents an excellent experimental tool for research on this malignancy in human.