Significance of Gene Polymorphism and Gene Expression of BACE2 in Swedish Patients with Colorectal Cancer.

INTRODUCTION: ß-site amyloid precursor protein (APP) cleaving enzyme 2 (BACE2) cleaves APP which is ubiquitously expressed in a variety of cell types including cancer cells. BACE2 can process APP in several ways and appears to be involved in the pathogenesis of cancer. Our purpose was to assess the association of mRNA expression and genetic polymorphism of BACE2 in colorectal cancer (CRC) susceptibility and its association to clinicopathological factors in Swedish patients with CRC. METHODS: A total of 720 CRC patients and 470 healthy controls were genotyped for BACE2 gene polymorphism rs2012050, using TaqMan single nucleotide polymorphism (SNP) assays based on polymerase chain reaction. Reverse transcription quantitative PCR was used to investigate the BACE2 gene expression in 192 CRC tissue and 181 paired normal tissue. RESULTS: Assessing clinicopathological factors, we noted that carrying of T allele in C/T and C/T+T/T was significantly associated with a protective role against disseminated cancer and higher lymph node status. Moreover, individuals carrying T/T genotype were significantly more likely to have poorly differentiated cancer. Follow-up data for patients in poorly differentiated cancer and the Kaplan-Meier analysis showed that the cancer-specific survival curves differed between C/C and C/T+T/T for the BACE2 gene polymorphism and that the carriers of the genotype C/C were associated with more favorable prognosis. We found no significant differences in the genotypic frequencies between the patients and healthy controls. BACE2 mRNA level was significantly 2.2-fold upregulated in CRC tissue when compared to noncancerous tissue. A higher BACE2 mRNA level was observed in smaller tumors and in rectal cancer when compared to colon cancer. CONCLUSION: In patients with CRC, our results indicate BACE2 rs2012050 as a useful potential predictor of poor differentiation, disseminated cancer and lymph node status and that the BACE2 mRNA expression is associated to tumor size and cancer location.

Metformin Prescription Associated with Reduced Abdominal Aortic Aneurysm Growth Rate and Reduced Chemokine Expression in a Swedish Cohort.

BACKGROUND: Recent reports suggest that the negative association between diabetes mellitus and abdominal aortic aneurysm (AAA) may be driven by metformin, the world's most common antidiabetic drug rather than diabetes per se. We sought to investigate the association among AAA growth rate, chemokine profile, and metformin prescription in a contemporary Swedish cohort. METHODS: Patients under surveillance for small AAA were identified at 4 Swedish vascular centers with active AAA screening programs. Annual AAA growth rate, medical history, and prescribed medications were recorded for linear regression analysis. In a subset of patients with AAA and control subjects without AAA or diabetes, plasma samples were available and analyzed for 40 inflammatory chemokines. RESULTS: A total of 526 patients were included for AAA growth analysis: 428 without type 2 diabetes mellitus (T2DM), 65 with T2DM and metformin prescription, and 33 with T2DM but without metformin prescription. Patients were included from 2005 to 2017 with mean follow-up of 3.2 (1.7) years and median annual AAA growth rate 1.6 mm, range -4.8 to 15.4 mm. Mean (standard deviation) annual AAA growth rates were 2.3 (2.2) mm in non-T2DM patients versus 1.1 (1.1) mm in patients with T2DM with metformin prescription and 1.6 (1.4) mm among those with T2DM without metformin prescription. With non-T2DM patients as reference in an unadjusted and 2 adjusted models, metformin prescription was significantly associated with reduced AAA growth rate (P < 0.001, P = 0.005, and P = 0.024, respectively), but not T2DM without metformin prescription (P = 0.137, P = 0.331, and P = 0.479, respectively). Among 240 patients with AAA (152 without T2DM, 51 with T2DM and metformin, and 37 with T2DM without metformin) and 59 without AAA or T2DM, metformin prescription was associated with reduced expression of chemokines representing all classes of leukocytes. CONCLUSIONS: Metformin prescription is associated with reduced AAA growth rate, possibly mediated by broad anti-inflammatory effects. A randomized controlled trial is needed to determine what role metformin may play in AAA disease, particularly in the absence of T2DM.

Cysteinyl leukotriene receptor 1 antagonism prevents experimental abdominal aortic aneurysm.

Cysteinyl-leukotrienes (cys-LTs) are 5-lipoxygenase-derived lipid mediators involved in the pathogenesis and progression of inflammatory disorders, in particular asthma. We have previously found evidence linking these mediators to increased levels of proteolytic enzymes in tissue specimens of human abdominal aortic aneurysm (AAA). Here we show that antagonism of the CysLT1 receptor by montelukast, an established antiasthma drug, protects against a strong aorta dilatation (>50% increase = aneurysm) in a mouse model of CaCl2-induced AAA at a dose comparable to human medical practice. Analysis of tissue extracts revealed that montelukast reduces the levels of matrix metalloproteinase-9 (MMP-9) and macrophage inflammatory protein-1α (MIP-1α) in the aortic wall. Furthermore, aneurysm progression was specifically mediated through CysLT1 signaling since a selective CysLT2 antagonist was without effect. A significantly reduced vessel dilatation is also observed when treatment with montelukast is started days after aneurysm induction, suggesting that the drug not only prevents but also stops and possibly reverts an already ongoing degenerative process. Moreover, montelukast reduced the incidence of aortic rupture and attenuated the AAA development in two additional independent models, i.e., angiotensin II- and porcine pancreatic elastase-induced AAA, respectively. Our results indicate that cys-LTs are involved in the pathogenesis of AAA and that antagonism of the CysLT1 receptor is a promising strategy for preventive and therapeutic treatment of this clinically silent and highly lethal disease.

Increased cardiovascular mortality in females with the a/a genotype of the SNPs rs1478604 and rs2228262 of thrombospondin-1.

BACKGROUND: Cardiovascular diseases are still the major cause of death in the Western world, with different outcomes between the two genders. Efforts to identify those at risk are therefore given priority in the handling of health resources. Thrombospondins (TSP) are extracellular matrix proteins associated with cardiovascular diseases. The aim of this study was to investigate variations in single nucleotide polymorphisms (SNPs) of TSP-1 and plasma expression, and associations with mortality from a gender perspective. METHODS: A population of 470 community-living persons were invited to participate. The participants were followed for 7.9 years and underwent a clinical examination and blood sampling. SNP analyses of TSP-1 rs1478604 and rs2228262 using allelic discrimination and plasma measurement of TSP-1 using ELISA were performed, RESULTS: During the follow-up period, 135 (28.7%) all-cause and 83 (17.7%) cardiovascular deaths were registered. In the female population, the A/A genotype of rs2228262 and the T/T genotype of rs1478604 exhibited significantly more cardiovascular deaths compared with the A/G and G/G, or the T/C and C/C genotypes amalgamated (rs2228262: 13.7% vs 2.0%; Χ2:5.29; P = 0.02; rs1478604:17.7% vs 4.7%; Χ2:9.50; P = 0.002). Applied in a risk evaluation, the A/A, or T/T genotypes exhibited an increased risk of cardiovascular mortality (rs2228262: HR: 7.1; 95%CI 1.11-45.8; P = 0.04; rs1478604: HR: 3.18; 95%CI 1.35-7.50; p = 0.008). No differences among the three genotypes could be seen in the male group. CONCLUSION: In this study the female group having the A/A genotype of rs2228262, or the T/T genotype of rs1478604 of TSP-1 exhibited higher cardiovascular mortality after a follow-up of almost 8 years. No corresponding genotype differences could be found in the male group. Genotype evaluations should be considered as one of the options to identify individuals at risk. However, this study should be regarded as hypothesis-generating, and more research in the field is needed.

Altered IL-32 Signaling in Abdominal Aortic Aneurysm.

INTRODUCTION AND OBJECTIVE: Interleukin (IL)-32 is a pro-inflammatory cytokine not previously studied in relation to abdominal aortic aneurysm (AAA). The aim of this study was to elucidate the expression and localization of IL-32 in AAA. METHODS: Expression and localization of IL-32 in human aortic tissue was studied with immunohistochemical analysis and Western blot (AAA: n = 5; controls: n = 4). ELISA was used to measure IL-32 in human plasma samples (AAA: n = 140; controls: n = 37) and in media from cultured peripheral blood mononuclear cells (PBMCs) from 3 healthy donors. IL-32 mRNA in PBMCs, endothelial cells, aortic smooth muscle cells (SMCs), and aortic tissue samples of AAA (n = 16) and control aortas (n = 9) was measured with qPCR. RESULTS: IL-32 was predominantly expressed in SMCs and T-cell-rich areas. Highest mRNA expression was observed in the intima/media layer of the AAA. A weaker protein expression was detected in non-aneurysmal aortas. Expression of IL-32 was confirmed in isolated T cells, macrophages, endothelial cells, and SMCs, where expression was also inducible by cytokines such as interferon-γ. There was no difference in IL-32 expression in plasma between patients and controls. CONCLUSION: IL-32 signaling is altered locally in AAA and could potentially play an important role in aneurysm development. Further studies using animal models would be helpful to study its potential role in AAA disease.

Possible Role and Therapeutic Target of PDGF-D Signalling in Colorectal Cancer.

Platelet-derived growth factor D (PDGF-D) has been shown to mediate cellular processes of importance in cancer progression. This study aimed to investigate the expression and putative involvement of PDGF-D signaling in colorectal carcinogenesis. PDGF-D was expressed in vascular endothelial cells in tumor and normal tissues. PDGF-D stimulation of cells altered genes of importance in carcinogenic processes. In addition, PDGF-D increased the proliferation rate while imatinib inhibited these effects. PDGF-D and its PDGF receptor beta (PDGFR-ß) are expressed in colorectal cancer and blockage of PDGF-D/PDGFR-ß signaling using tyrosine kinase inhibitors, such as imatinib, might be important in inhibiting tumor-promoting actions.

Inflammatory cells, ceramides, and expression of proteases in perivascular adipose tissue adjacent to human abdominal aortic aneurysms.

BACKGROUND: Abdominal aortic aneurysm (AAA) is a deadly irreversible weakening and distension of the abdominal aortic wall. The pathogenesis of AAA remains poorly understood. Investigation into the physical and molecular characteristics of perivascular adipose tissue (PVAT) adjacent to AAA has not been done before and is the purpose of this study. METHODS AND RESULTS: Human aortae, periaortic PVAT, and fat surrounding peripheral arteries were collected from patients undergoing elective surgical repair of AAA. Control aortas were obtained from recently deceased healthy organ donors with no known arterial disease. Aorta and PVAT was found in AAA to larger extent compared with control aortas. Immunohistochemistry revealed neutrophils, macrophages, mast cells, and T-cells surrounding necrotic adipocytes. Gene expression analysis showed that neutrophils, mast cells, and T-cells were found to be increased in PVAT compared with AAA as well as cathepsin K and S. The concentration of ceramides in PVAT was determined using mass spectrometry and correlated with content of T-cells in the PVAT. CONCLUSIONS: Our results suggest a role for abnormal necrotic, inflamed, proteolytic adipose tissue to the adjacent aneurysmal aortic wall in ongoing vascular damage.

Increased arterial blood pressure and vascular remodeling in mice lacking salt-inducible kinase 1 (SIK1).

RATIONALE: In human genetic studies a single nucleotide polymorphism within the salt-inducible kinase 1 (SIK1) gene was associated with hypertension. Lower SIK1 activity in vascular smooth muscle cells (VSMCs) leads to decreased sodium-potassium ATPase activity, which associates with increased vascular tone. Also, SIK1 participates in a negative feedback mechanism on the transforming growth factor-ß1 signaling and downregulation of SIK1 induces the expression of extracellular matrix remodeling genes. OBJECTIVE: To evaluate whether reduced expression/activity of SIK1 alone or in combination with elevated salt intake could modify the structure and function of the vasculature, leading to higher blood pressure. METHODS AND RESULTS: SIK1 knockout (sik1(-/-)) and wild-type (sik1(+/+)) mice were challenged to a normal- or chronic high-salt intake (1% NaCl). Under normal-salt conditions, the sik1(-/-) mice showed increased collagen deposition in the aorta but similar blood pressure compared with the sik1(+/+) mice. During high-salt intake, the sik1(+/+) mice exhibited an increase in SIK1 expression in the VSMCs layer of the aorta, whereas the sik1(-/-) mice exhibited upregulated transforming growth factor-ß1 signaling and increased expression of endothelin-1 and genes involved in VSMC contraction, higher systolic blood pressure, and signs of cardiac hypertrophy. In vitro knockdown of SIK1 induced upregulation of collagen in aortic adventitial fibroblasts and enhanced the expression of contractile markers and of endothelin-1 in VSMCs. CONCLUSIONS: Vascular SIK1 activation might represent a novel mechanism involved in the prevention of high blood pressure development triggered by high-salt intake through the modulation of the contractile phenotype of VSMCs via transforming growth factor-ß1-signaling inhibition.

PDGF-D gene polymorphism is associated with increased cardiovascular mortality in elderly men.

BACKGROUND: Platelet-derived growth factor (PDGF) D has been reported to be active in fibroblasts, and in areas of myocardial infarction. In this longitudinal study we evaluated the association between PDGF-D polymorphism and cardiovascular mortality, and attempted to discover whether specific genotype differences regarding risk could be observed, and if gender differences could be seen. METHODS: Four hundred seventy-six elderly community participants were included in this study. All participants underwent a clinical examination, echocardiography, and blood sampling including PDGF-D single nucleotide polymorphism (SNP) analyses of the rs974819 A/A, G/A and G/G SNP. The follow-up time was 6.7 years. RESULTS: No specific genotype of rs974819 demonstrated increased cardiovascular mortality in the total population, however, the male group with genotypes A/A and G/A demonstrated an increased risk that persisted in a multivariate evaluation where adjustments were made for well-known cardiovascular risk factors (2.7 fold compared with the G/G genotype). No corresponding finding was observed in the female group. CONCLUSION: We report here for the first time that the genotypes G/A or A/A of the SNP rs974819 near PDGF-D exhibited a 2.7 fold increased cardiovascular mortality risk in males. Corresponding increased risk could not be observed in either the total population and thus not in the female group. However, the sample size is was small and the results should be regarded as hypothesis-generating, and thus more research in the field is recommended.

Altered PPARγ Coactivator-1 Alpha Expression in Abdominal Aortic Aneurysm: Possible Effects on Mitochondrial Biogenesis.

INTRODUCTION: Abdominal aortic aneurysm (AAA) is a complex and deadly vascular disorder. The pathogenesis of AAA includes destruction and phenotypic alterations of the vascular smooth muscle cells (VSMCs) and aortic tissues. PPARγ coactivator-1 alpha (PGC1α) regulates VSMC migration and matrix formation and is a major inducer of mitochondrial biogenesis and function, including oxidative metabolism. METHODS: Protein and gene expression of PGC1α and markers for mitochondria biogenesis and cell type-specificity were analysed in AAA aortas from humans and mice and compared against control aortas. RESULTS: Gene expression of PPARGC1A was decreased in human AAA and angiotensin (Ang) II-induced AAA in mice when compared to control vessels. However, high expression of PGC1α was detected in regions of neovascularisation in the adventitia layer. In contrast, the intima/media layer of AAA vessel exhibited defective mitochondrial biogenesis as indicated by low expression of PPARGC1A, VDAC, ATP synthase and citrate synthase. CONCLUSION: Our results suggest that mitochondrial biogenesis is impaired in AAA in synthetic SMCs in the media, with the exception of newly formed supporting vessels in the adventitia where the mitochondrial markers seem to be intact. To our knowledge, this is the first study investigating PGC1α and mitochondria biogenesis in AAA.

Prognostic significance of PLA2G4C gene polymorphism in patients with stage II colorectal cancer.

BACKGROUND: Phospholipase A2 Group IV C (PLA2G4C) catalyzes the release of certain fatty acids from phospholipids and plays a role in a range of physiological functions, such as remodeling of cell membranes and the production of prostaglandins. Furthermore, it has been proposed that PLA2G4C plays an important role in breast cancer cell chemotaxis. This study aimed to investigate the effect of a single nucleotide polymorphism (SNP) rs1549637 (T>A) of the PLA2G4C gene on the prognosis of colorectal cancer (CRC). MATERIAL AND METHODS: Whole blood DNA was extracted from 381 patients with CRC and 618 controls, and a TaqMan SNP genotyping assay was used to determine the distribution of the genotypes. Cancer-specific and disease-free survival was analyzed by Kaplan-Meier graphs and by uni- and multivariable Cox regression. RESULTS: The cancer-specific survival differed between the genotypes (p = 0.019) and the carriers of the A allele were associated with the highest risk of CRC death, with a hazard ratio (HR) of 1.72 [95% confidence interval (CI) 1.17-2.53, p = 0.006] compared with homozygous carriers of the T allele. This increased mortality in the carriers with the allele A was especially marked in stage II with an HR of 3.84 (95% CI 1.51-9.78, p = 0.005). CONCLUSION: The A allele in PLA2G4C SNP (rs1549637) is associated with a worse prognosis in patients with CRC, especially in stage II disease, and it could be a potential prognostic biomarker in the planning of individual adjuvant therapy in stage II patients.

Gender difference in adiponectin associated with cardiovascular mortality.

BACKGROUND: It is important to identify cardiovascular diseases in patients at high risk. To include genetics into routine cardiological patients has therefore been discussed recently. We wanted to evaluate the association between high-molecular weight adiponectin and cardiovascular risk, and secondly in the same population evaluate if specific genotype differences regarding risk could be observed, and thirdly if gender differences could be seen. METHOD: Four hundred seventy-six elderly participants recruited from a rural community were included. All participants underwent a clinical examination, echocardiography, and blood sampling and the single nucleotide polymorphism (SNP) (rs266729) of adiponectin was analysed. Follow-up time was 6.7 years. RESULTS: Those with high serum concentration of adiponectin had a more 2 fold increased cardiovascular risk, and it might be that females exhibits even higher risk where a more than 5 fold increased risk could be seen. The result could be demonstrated even in a multivariate model adjusting for well-known clinical risk factors. However, as the sample size was small the gender differences should be interpreted with caution. In the genotype evaluation the C/C carriers of the female group had a more than 9-fold increased risk of cardiovascular mortality, however the confidence interval was wide. Such genotype difference could not be found in the male group. CONCLUSION: High level of adiponectin was associated with increased cardiovascular risk. Also a gender difference in the genotype evaluation could be seen where the C/C carriers obtained higher risk in the female group but not in the male group. Thus, in order to identify patients at risk early, genetic analyses may add to the armamentarium used in the clinical routine. However, information should be regarded as hypothesis generating as the sample size was small and should stimulate further research in individualized cardiovascular prevention and treatment.

CD93 gene polymorphism is associated with disseminated colorectal cancer.

PURPOSE: Cluster of differentiation 93 (CD93) is involved in apoptosis and inflammation and has a suggested role in angiogenesis, and all of which are involved in the development and dissemination of cancer. We evaluated the expression of CD93 and the association with two single nucleotide polymorphisms (SNPs), rs2749812 and rs2749817, as possible biomarkers in colorectal cancer (CRC). METHODS: Tissue levels and plasma levels of CD93 were measured using an enzyme-linked immunosorbent assay (ELISA). Expression of CD93 was determined by immunohistochemistry, western blot and gene expression analysis. Genotype frequencies were established for the SNPs by real-time polymerase chain reaction (PCR), and the association with tumour stage and survival was analysed. RESULTS: Total CD93 levels were 82% higher (P < 0.001) in tumours compared to matched normal tissues. Mean levels of soluble CD93 in plasma were 30% lower (P < 0.001) in the patients compared to the controls. The T/T genotype of SNP rs2749817 was more common in stage IV patients, with consequently higher risk of CRC death (T/T vs. C/C and C/T; hazard ratio (HR) = 1.73, 95% confidence interval (CI) = 1.11-2.67, P = 0.014), and was associated with a higher risk of CRC recurrence after radical operation (T/T vs. C/C and C/T; HR = 2.07, CI = 1.22-3.51, P = 0.007). CONCLUSIONS: We showed that the T/T genotype of SNP rs2749817 is associated with disseminated cancer at diagnosis and an increased recurrence rate after radical operation. Patients with this genotype may benefit from early identification.

Emerging role and clinical implication of mRNA scavenger decapping enzyme in colorectal cancer.

BACKGROUND: Turnover of RNA is a regulated process that in part controls gene expression. This process is partly controlled by the scavenger decapping enzyme (DcpS). This study aimed to investigate the expression of DcpS in colorectal cancer (CRC) tissue, to evaluate its prognostic significance in patients with CRC and to investigate potentially targeted genes by DcpS. METHODS: Immunohistochemical analysis was used to determine localization of DcpS in normal and CRC tissue, western blot analysis for quantification of protein expression and qPCR for mRNA expression in normal and CRC tissue and expression in cell lines after silencing using siRNA. Gene array analysis was used to study regulation of genes after silencing of DcpS. Proliferation was studied using BRDU. RESULTS: DcpS expression was localized to the epithelial cells of both control and cancer tissue. Tumor and paired control tissue samples from 100 patients who underwent surgical resection for primary colorectal adenocarcinomas were utilized. mRNA and protein of DcpS was significantly up-regulated in the patients with CRC and the mRNA level was higher in rectal cancer tissue compared to colon cancer tissue (p < 0.05). Lowest tertile levels of DcpS mRNA in cancer tissue was associated with a decreased cancer-specific survival rate with a hazard ratio (HR) of 4.7 (95% CI=1.02-12.3), independent of disease stage. The low level of DcpS mRNA was a predictor of poorer survival in patients with rectal and disseminated cancer and in patients receiving adjuvant treatment (p < 0.05). After silencing DcpS in Caco-2 cancer cells, altered expression of several genes associated with RNA, cell cycle regulation, alternative splicing and microRNA was observed and resulted in 23% increase in proliferation. CONCLUSIONS: These results indicate that DcpS has potential as a prognostic factor for CRC but further studies in a broader cohort are warranted to evaluate the significance of the findings in the clinic.

Association of Clinicopathological Factors With MMP13 (rs2252070) Gene Polymorphism in Swedish Patients With Colorectal Cancer.

BACKGROUND/AIM: Matrix metalloproteinase 13 (MMP13) has been reported to be involved in tumor development and progression, including of colorectal cancer (CRC). This study aimed at evaluating whether the MMP13 rs2252070 gene polymorphism is associated with clinicopathological factors and its influence on long-term survival in Swedish patients with CRC. PATIENTS AND METHODS: A total of 723 patients with CRC were genotyped using TaqMan single nucleotide polymorphism assays based on polymerase chain reaction. RESULTS: Assessing clinicopathological factors, we demonstrated that having the G/G genotype for MMP13 rs2252070 was significantly associated with poor differentiation, higher serum level of carcinoembryonic antigen and higher lymph node status. Moreover, the presence of a G allele was significantly related to larger tumor size in rectal cancer but had a significantly protective role against mucinous cancer, perineural invasion and lymphovascular invasion. Kaplan-Meier analysis showed no difference between genotypes regarding cancer-specific survival. CONCLUSION: Our findings highlight the potential of MMP13 rs2252070 polymorphism as a useful predictor of poor differentiation, serum level of carcinoembryonic antigen, lymph node status, tumor size, mucinous cancer, perineural invasion and lymphovascular invasion in patients with CRC.

Sustained IFN signaling is associated with delayed development of SARS-CoV-2-specific immunity.

Plasma RNAemia, delayed antibody responses and inflammation predict COVID-19 outcomes, but the mechanisms underlying these immunovirological patterns are poorly understood. We profile 782 longitudinal plasma samples from 318 hospitalized patients with COVID-19. Integrated analysis using k-means reveals four patient clusters in a discovery cohort: mechanically ventilated critically-ill cases are subdivided into good prognosis and high-fatality clusters (reproduced in a validation cohort), while non-critical survivors segregate into high and low early antibody responders. Only the high-fatality cluster is enriched for transcriptomic signatures associated with COVID-19 severity, and each cluster has distinct RBD-specific antibody elicitation kinetics. Both critical and non-critical clusters with delayed antibody responses exhibit sustained IFN signatures, which negatively correlate with contemporaneous RBD-specific IgG levels and absolute SARS-CoV-2-specific B and CD4+ T cell frequencies. These data suggest that the "Interferon paradox" previously described in murine LCMV models is operative in COVID-19, with excessive IFN signaling delaying development of adaptive virus-specific immunity.

Increased expression of leukotriene C4 synthase and predominant formation of cysteinyl-leukotrienes in human abdominal aortic aneurysm.

Leukotrienes (LTs) are arachidonic acid-derived lipid mediators involved in the pathogenesis and progression of diverse inflammatory disorders. The cysteinyl-leukotrienes LTC(4), LTD(4), and LTE(4) are important mediators of asthma, and LTB(4) has recently been implicated in atherosclerosis. Here we report that mRNA levels for the three key enzymes/proteins in the biosynthesis of cysteinyl-leukotrienes, 5-lipoxygenase (5-LO), 5-LO-activating protein (FLAP), and LTC(4) synthase (LTC(4)S), are significantly increased in the wall of human abdominal aortic aneurysms (AAAs). In contrast, mRNA levels of LTA(4) hydrolase, the enzyme responsible for the biosynthesis of LTB(4), are not increased. Immunohistochemical staining of AAA wall revealed focal expression of 5-LO, FLAP, and LTC(4)S proteins in the media and adventitia, localized in areas rich in inflammatory cells, including macrophages, neutrophils, and mast cells. Human AAA wall tissue converts arachidonic acid and the unstable epoxide LTA(4) into significant amounts of cysteinyl-leukotrienes and to a lesser extent LTB(4). Furthermore, challenge of AAA wall tissue with exogenous LTD(4) increases the release of matrix metalloproteinase (MMP) 2 and 9, and selective inhibition of the CysLT1 receptor by montelukast blocks this effect. The increased expression of LTC(4)S, together with the predominant formation of cysteinyl-leukotrienes and effects on MMPs production, suggests a mechanism by which LTs may promote matrix degradation in the AAA wall and identify the components of the cysteinyl-leukotriene pathway as potential targets for prevention and treatment of AAA.

Clinicopathological and prognostic value of CD44 gene polymorphism (rs187115) in Swedish patients with colorectal cancer.

Cluster of differentiation (CD) 44 plays a crucial role in apoptosis, cell-cell interactions, angiogenesis, metastasis and proliferation. The aim of the present study was to examine the influence of CD44 gene polymorphism rs187115 on colorectal cancer (CRC) susceptibility and the association with various clinical features including long-term survival in Swedish patients with CRC. Genotypes were screened, using TaqMan single nucleotide polymorphism (SNP) assays based on polymerase chain reaction, in 612 CRC patients and 575 healthy controls.The carriers of G allele, genotypes (AG + GG), were found to be associated with an increased risk of CRC with an odds ratio (OR) of 1.35 (95% confidence interval (CI) = 1.01-1.81; p = 0.039) and found to be more common in patients with mucinous cancer compared with non-mucinous cancer, OR = 1.69 (95% CI = 1.02-2.80; p = 0.011). By using Kaplan-Meier analysis, the patients with genotype GG showed shorter cancer-specific and recurrence free survival with a hazard ratio (HR) of 1.25 (95% CI = 1.02-1.54; p = 0.036) and 1.52 (95% CI = 1.12-2.06; p = 0.007), respectively, in comparison with the carriers of A allele (AG + AA). The present findings demonstrated that the variant G allele of CD44 gene polymorphism rs187115 was related to risk for CRC and associated to mucinous cancer and predict worse prognosis in Swedish patients with CRC.

Impaired splicing of fibronectin is associated with thoracic aortic aneurysm formation in patients with bicuspid aortic valve.

OBJECTIVE: Thoracic aortic aneurysm is a common complication in patients with bicuspid aortic valve (BAV). Alternatively spliced extra domain A (EDA) of fibronectin (FN) has an essential role in tissue repair. Here we analyze the expression of FN spliceforms in dilated and nondilated ascending aorta of tricuspid aortic valve (TAV) and BAV patients. METHODS AND RESULTS: The mRNA expression was analyzed in the ascending aorta by Affymetrix Exon arrays in patients with TAV (n=40) and BAV (n=69). EDA and extra domain B (EDB) expression was increased in dilated aorta from TAV patients compared with nondilated aorta (P<0.001 and P<0.05, respectively). In contrast, EDA expression was not increased in dilated aorta from BAV patients (P=0.25), whereas EDB expression was upregulated (P<0.01). The expression of EDA correlated with maximum aortic diameter in TAV (ρ=0.58) but not in BAV (ρ=0.15) patients. Protein analyses of EDA-FN showed concordant results. Transforming growth factor-ß treatment influenced the splicing of FN and enhanced the formation of EDA-containing FN in cultured medial cells from TAV patients but not in cells derived from BAV patients. Gene set enrichment analysis together with multivariate and univariate data analyses of mRNA expression suggested that differences in the transforming growth factor-ß signaling pathway may explain the impaired EDA inclusion in BAV patients. CONCLUSIONS: Decreased EDA expression may contribute to increased aneurysm susceptibility of BAV patients.