Brain cortical maturation assessed by magnetic resonance imaging in unaffected or mildly affected fetuses with cytomegalovirus infection

OBJECTIVES

To assess by magnetic resonance imaging (MRI) the cortical maturation pattern in fetuses with cytomegalovirus (CMV) infection with mild or no abnormalities on ultrasound (US) and MRI, and to establish possible differences compared with healthy controls.

METHODS

This was a retrospective case-control study of consecutive pregnancies with a CMV-infected fetus undergoing prenatal MRI as a complementary diagnostic tool in two centers, and a control group of singleton low-risk pregnancies without fetal structural abnormalities, with normal fetal growth and with healthy newborns. CMV infection was confirmed by extraction of CMV-DNA from fetal and neonatal samples. Only fetuses with mild (mildly affected) or no (unaffected) neuroimaging abnormalities on US and MRI were included. MRI measurements of fetal parieto-occipital sulcus, cingulate sulcus and calcarine sulcus depth, Sylvian fissure depth and Sylvian fissure angles were performed and cortical development grading of specific cortical areas and sulci were assessed by one operator who was blinded to CMV infection status. Data were compared between controls and fetuses with CMV infection, using linear regression and non-parametric trend analysis.

RESULTS

Twenty-four CMV-infected fetuses (seven unaffected and 17 mildly affected) and 24 healthy controls that underwent fetal MRI between 27 and 36 weeks' gestation were included. Compared with controls, CMV-infected fetuses showed significantly larger median lateral ventricular width (right side, 7.8 (interquartile range (IQR), 5.9-9.9) mm vs 3.9 (IQR, 2.6-5.3) mm; left side, 7.5 (IQR, 6.0-10.9) mm vs 4.2 (IQR, 3.2-5.3) mm), significantly decreased parieto-occipital sulcus depth (right side, 12.6 (IQR, 11.3-13.5) mm vs 15.9 (IQR, 13.5-17.3) mm; left side, 12.3 (IQR, 10.6-13.5) mm vs 16.0 (IQR, 13.3-17.5) mm) and calcarine sulcus depth (right side, 15.4 (IQR, 14.4-16.3) mm vs 17.5 (IQR, 16.1-18.7) mm; left side, 14.6 (IQR, 14.1-15.6) mm vs 16.7 (IQR, 15.6-18.9) mm) (P < 0.001 for all). Compared with controls, CMV-infected fetuses also had significantly smaller upper (right side, 42.8° (IQR, 35.8-45.8°) vs 48.9° (IQR, 38.4-64.7°); left side, 40.9° (IQR, 34.2-45.8°) vs 48.2° (IQR, 41.9-60.7°)) and lower (right side, 41.6° (IQR, 34.4-49.2°) vs 48.9° (IQR, 40.6-60.9°); left side, 42.2° (IQR, 38.8-46.9°) vs 48.9° (IQR, 39.5-57.5°)) Sylvian fissure angles (P < 0.05 for all). In addition, the mildly affected CMV-infected fetuses had a significantly lower cortical development grading in the temporal and parietal areas, and the parieto-occipital and calcarine sulci compared with healthy fetuses (P < 0.05). These differences persisted when adjusting for gestational age, ipsilateral atrium width, fetal gender and when considering small-for-gestational age as a confounding factor.

CONCLUSIONS

Unaffected and mildly affected CMV-infected fetuses showed delayed cortical maturation compared with healthy controls. These results suggest that congenital CMV infection, even in non-severely affected fetuses that are typically considered of good prognosis, could be associated with altered brain cortical structure. Further research is warranted to better elucidate the correlation of these findings with neurodevelopmental outcomes. © 2022 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Iron status, anemia and functional capacity in adults with congenital heart disease: a single center analysis

Background

Iron is essential to the mitochondrial energy production in cardiomyocytes and its depletion is negatively associated with symptoms, functional capacity, quality of life and outcomes in patients with heart failure – independent of anemia. The relevance of iron deficiency in adults with congenital heart disease however has not been evaluated to date, and we thus aimed to evaluate it in an all-comer cohort of patients with congenital heart disease in correlation with symptoms and functional capacity.

Methods and results

527 patient cases from one referral center over 2 years were evaluated concerning their iron status, anemia, functional capacity and ejection fraction of their systemic ventricle. 264 were female, 94 had a shunt lesion, 96 had left-sided obstructive lesions, 181 right-sided lesions, while 108 were considered to have complex lesions and 28 were cyanotic. The median age was 34 years, the mean BMI was 25.2±5 kg/m2, 429 patients had a normal ejection fraction and 34 moderately and severely depressed. 35 patients were classified as NYHA III, and 56 as NYHA II, while their functional capacity was evaluated via cardiopulmonary testing with a mean VO2max/kg of 22.6±6.5 and mean 69±17% of the expected. The mean serum iron concentration was 99.4±42.3 mcg/dL, their mean transferrin saturation was 27.36±13%, the mean ferritin concentration was 130.8±185 ng/mL, the mean soluble transfer factor was 1.3±0.66 mg/l and their mean Hemoglobin 14.8±2 mg/dL, while the mean MCV was 88±5.3 and the mean MCHC 33.7±1.4.

40 patients were anemic according to the WHO definition for anemia, in 28 of those patients that was already known. Iron deficiency according to stratified according to ferritin was present in 53 patients. However, when stratified according to the heart failure guidelines definition for iron deficiency 299 patients were found affected. Using the soluble transferrin receptor (sTfR) and sTfR-ferritin index iron deficiency was suspected in 10 additional individuals. Iron deficiency was associated with the ejection fraction (p=0.0001) - patients with moderately or severely depressed systemic ventricular function more often were diagnosed with iron deficiency (p=0.007)-, while it did not correlate with functional NYHA classification (p=0.622) or functional capacity (p=0.1 and 0.057). Iron deficiency was also not found significantly different amongst congenital defects but did correlate with all laboratory iron studies.

Conclusions

In this ambulatory population of adults with congenital heart disease we found an association of ejection fraction with iron deficiency, however no association of iron deficiency with functional capacity. The question arising is if a new definition of iron deficiency anemia in congenital heart disease similar to heart failure would be of clinical value.

Funding Acknowledgement

Type of funding source: None

Oleanolic acid protection against experimental autoimmune myocarditis modulates the microbiota and the intestinal barrier integrity

Background

Autoimmune myocarditis is a cause of dilated cardiomyopathy and heart failure. Recent studies have indicated that leaky gut may allow environmental factors to enter the body and trigger the initiation/development of autoimmune disease. Moreover, there is a growing literature supporting that, beside myocardial fibrosis, a leaky intestinal barrier and gut dysbiosis are pathogenic factors linked to heart failure. The natural triterpene oleanolic acid (OA) has been shown to beneficially influence the severity of the experimental autoimmune myocarditis (EAM), a preclinical model of human myocarditis, via anti-oxidant and immunomodulatory mechanisms. Herein, we investigate gastrointestinal (GI) disturbances and the gut microbiota composition associated with EAM as potential therapeutic target of OA.

Methods and results

BALB/c mice were α-myosin-inmunized to induce EAM and treated with OA (25 mg/kg/day, i.p). On day 21, heart fibrosis and parameters related to gut damage such as oxidative stress (O2- ions, lipid peroxidation), gut permeability (D-lactate; I-FABP), inflammation and mucins were determined in serum and/or colon. Fecal microbial profiles were identified by 16S rRNA gene sequencing analysis. Firstly, histological analysis of hearts showed presence of fibrosis (Sirius Red stain) in EAM mice, whereas these effects were not detectable in myocardium from healthy or OA-treated EAM mice. In addition, OA preserved the mucin-containing goblet cells along the colon (Alcian Blue/PAS stain). Consistently, serum levels of the epithelial gut damage markers, including D-lactate and iFABP were significantly reduced in OA treated-EAM mice. The beneficial OA effects also included a decrease in the pro-inflammatory mediators sPLA2-IIA and IL-1β and a protection from the oxidative stress response (DHE stain and TBARS) in serum and colonic tissue of EAM-mice. Furthermore, gut microbiota composition showed a lower bacterial diversity and different relative abundance of certain bacterial taxa in EAM-mice compared to control mice. The families of Muribaculaceae, Lachnospiraceae, and Ruminococcaceae were significantly affected in EAM mice, and only Muribaculaceae recovered levels similar to the healthy-control group, after treatment with OA.

Conclusion

Our data show that in addition to the heart, the intestinal barrier and gut microbiota are altered in myocarditis, and that OA treatment could ameliorate this profile. Our data contribute to the idea that gut dysbiosis and GI dysfunction influences myocarditis pathogenesis, and provides new findings regarding the beneficial activity of OA in EAM, suggesting that it may be an interesting candidate to be explored for the treatment of human patients.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): MINECO, ISCIII, CIBERCV-ISCIII

P6284The antioxidant MitoQ protects against intestinal disturbances in the experimental autoimmune model of myocarditis

Purpose

Myocarditis and dilated cardiomyopathy represent the acute and chronic phases of an inflammatory disease of the myocardium, for which no standardized treatment is currently available in clinical practice. Myocardial fibrosis an oxidative stress are pathogenic factors associated with these processes. However, new research has found that gut health can be linked to some cardiac conditions. Thus, in this study we investigated whether intestinal disturbances are present in myocarditis, using a murine experimental autoimmune model (EAM) that mimics human myocarditis, as well as the potential beneficial effect of treatment with the mitochondrial antioxidant, MitoQ.

Methods and results

EAM was induced in BALB/c mice with a myocardiogenic peptide and mice were treated with MitoQ (50 mg/kg/day, i.p). On day 21 (acute phase), we assessed signs of heart injury (e.g. hypertrophy, fibrosis, oxidative stress) and parameters related to gut damage such as accumulation of reactive oxigen species (superoxide anion: O2·−), inflammation (IL-1β, IL-33, TNFα), microbial translocation (sCD14; intestinal fatty acid binding protein, I-FABP) and mucins in serum and/or intestine. MitoQ teatment significantly reduced the high heart weight/body weight ratio (HW/BW) of EAM mice, a characteristic hallmark of cardiac hyperthropy. Histological analysis of hearts showed presence of fibrosis (Sirius Red stain) and high O2·− levels (DHE stain) in EAM mice whereas these effects were not detectable in cardiac tissue from healthy or MitoQ-treated EAM mice. In addition, the enhanced O2·− ions (DHE stain) and mucin loss (Alcian Blu/PAS stain) found in colon, ileum, jejunum and duodenum sections from EAM mice were attenuated by MitoQ treatment. The systemic markers associated to intestinal barrier disruption, sCD14 and I-FABP, were found strongly increased in serum from EAM mice, and MitoQ prevents this rise. The beneficial MitoQ effects were also associated with a decrease in the pro-inflammatory cytokines TNFα, IL-33 and IL-1β, both in serum and colonic tissue of treated-EAM mice, as well as a reduction of the myeloperoxidase activity in colon, compared with untreated EAM mice.

Conclusion

Our data show that in addition to the heart, the intestinal tissue is also damaged in the preclinical model of experimental autoimmune myocarditis, and that MitoQ treatment could reverse this profile. Since there are systemic markers released from the intestine, therapeutic strategies targeting to prevent the intestinal oxidative stress and its associated gut barrier dysfunction, could contribute to the amelioration of the disease.

Acknowledgement/Funding

SAF2016-81063; CIBERCV

[Diagnosis and treatment of nephrolithiasis and prevention of recurrences]

despite fluctuations, the prevalence of nephrolithiasis has significantly increased during the last decades in industrialized nations worldwide (1 to 15 %), which has a significant impact on the cost of healthcare. This increased prevalence is mainly explained by diet modifications. Environmental, metabolic and genetic factors may also influence the formation of kidney stones. As a consequence, the medical management of this disease is preferentially multidisciplinary and involves urologists, nephrologists, radiologists, biologists and dietitians. Urological management : may be mandatory during any acute and/or remote phase of an episode of renal colic, in case of residual stones. Several techniques are available: insertion of double J stent, extracorporeal shock wave lithotripsy, ureteroscopy (flexible or rigid), percutaneous nephrolithotomy and more occasionally, open surgery. Nephrological management: is justified in the course of the acute episode and aims to identify the causal factor(s) of kidney stones formation. The diagnostic approach involves a thorough interrogation (personal medical and surgical history, details of the kidney stone disease and family medical history) as well as a metabolic assessment. Moreover, given the high rate of recurrence (about 50 % within 5 to 10 years), individualized secondary prevention measures are necessary. The recommendations should take into account the identified risk factors and any metabolic abnormalities.

Abstract P6-08-06: Neoadjuvant tamoxifen therapy synchronizes ERα binding and gene expression profiles

Background: The majority of breast cancer patients are diagnosed with ERα-positive breast cancer. Most ERα-positive patients are treated with adjuvant endocrine therapy — typically tamoxifen or aromatase inhibitors — to block cellular proliferation. Although these treatments are considered successful, resistance is common. Notably, cross-resistance between the two types of therapies is not always observed suggesting molecular heterogeneity and underlining the need for development of personalized treatments. The Anastrozole, Fulvestrant or Tamoxifen Exposure — Response in molecular profile study (AFTER study, NCT00738777) aims to investigate prospectively whether short-term treatment can induce molecular changes indicative of pre-operative therapy response. Study Design: ERα-positive breast cancer patients are included in this open-label multicenter study. Post-menopausal patients are randomized between tamoxifen, anastrozole and fulvestrant and pre-menopausal and male patients receive tamoxifen. Treatment occurs during the pre-operative window between diagnosis and surgery (4±2 weeks). Clinical characteristics collected are ERα/PR and HER2 status as well as lymph-node status. The primary endpoint is the decrease in tumor cell proliferation, as assessed by Ki67 gene expression and published cell proliferation gene expression signatures. All data are collected from both pre- and post-treatment samples. Additionally, we will compare the changes induced by treatment in gene expression, ERα/DNA binding interactions, DNA copy number, endoxifen and estradiol levels. Results: Among 67 patients currently enrolled, we examined the data from the subset of 28 tamoxifen treated patients. ERα and PR levels did not differ significantly between pre- and post-treatment. All tumors were HER2-negative. Proliferation examined by Ki67 (IHC and gene expression, MKI67) was significantly lower in post-treatment samples (P &lt; 0.01). A significant association was identified with the change in gene expression proliferation signature score and change in MKI67 (rho = 0.7, P &lt; 0.001). We identified two samples, which changed from MammaPrint (MP) low-risk to high-risk among 17 pairs with data. One sample's score was on the cutoff for high-risk definition. Interestingly, the second sample also had an increase in Ki67 gene expression and proliferation gene signature score in the post-treatment sample. Overall, ERα/DNA binding interaction regions overlapped significantly more among post-treatment samples as compared to pre-treatment samples (P &lt;0.001). There were 3 samples that increased in MKI67 gene expression after drug exposure. Among these, only the MP low- to high-risk sample had an increase in proliferation gene signature and decrease in ERα/DNA binding interactions. Conclusions: Pre-treatment samples were more variable for both proliferation gene expression signatures and ERα/DNA binding interactions indicating the underlying molecular heterogeneity of the group prior to therapy. This inter-tumor heterogeneity appears to have been lowered by exposure to tamoxifen. Interestingly, not all samples were uniform in their response to tamoxifen exposure as measured by Ki67 and MP scores suggesting samples taken after treatment exposure may be useful for predictive biomarker discovery.

Citation Format: Linn SC, Severson TM, Nevedomskaya E, Peeters J, van Rossum A, Kuilman T, Krijgsman O, Goossens I, Glas A, Koornstra R, Peeper D, Wesseling J, Simon I, Wessels L, Zwart W. Neoadjuvant tamoxifen therapy synchronizes ERα binding and gene expression profiles. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P6-08-06.

[Recurrent episodes of brushite nephrolithiasis revealing primary hyperparathyroidism]

INTRODUCTION

Nephrolithiasis is a frequent disease observed in 1 to 20 % of the general population. This disease predominates in male patients (2:1) and is characterized by a high rate of recurrences (about 50 %).

CASE REPORT

We report the case of a 45-year old male patient who experienced during about ten years recurrent bilateral renal colic episodes due to brushite lithiasis. These stones were treated with multiple extracorporeal shock wave lithotripsy sessions. A pyeloureteral junction syndrome predisposing to bulky stones formation has been put in evidence and required a pyeloplasty. After more than ten years of disease activity, a biochemical screening diagnosed primary hyperparathyroidism (PHPT). Radiological assessment identified a parathyroid gland adenoma. Successful surgical removal of this lesion was followed by resolution of the symptomatic kidney stones formation.

DISCUSSION

PHPT is associated with kidney stones in about 20 % of the patients. Hypercalciuria is the main risk factor of stones formation but other predisposing factors are also probably involved. Patients carrying a polymorphism located in the coding sequence of the calcium-sensing receptor gene or in the regulatory region of this gene seem to experience an increased occurrence of urinary lithiasis.

CONCLUSION

The present case stresses the importance of a metabolic assessment in all patients with recurrent nephrolithiasis, especially in case of bilateral episodes.

[Contribution of clinical biology in the etiological exploration and follow-up of urolithiasis]

Urolithiasis is a frequent pathology with a constantly increasing prevalence in industrial countries. The relapse frequency is around 50 % with a risk of complications. The laboratory input is essential in the determination of the etiology and in the therapeutic monitoring. The morphoconstitutional analysis of the stone is the most important element. It comprises the examination of the stone with binocular loupes and the simultaneous analysis of its crystalline composition. This can be done by different techniques but infrared spectrophotometry is the most powerful. The chemical analysis should be definitely proscribed. The analysis of crystalluria includes the search, the identification and the counting of crystals in fresh morning urines. It is useful for the diagnosis and for the patient follow-up. Finally, the biochemical analyses in urine and serum, in first line or on the basis of the stone composition, are an important part of the etiological exploration and therapeutic monitoring.

Abstract P3-06-01: Hotspot mutations in PIK3CA are predictive for treatment outcome on aromatase inhibitors but not for tamoxifen

Introduction: PIK3CA is the most frequent (30%) mutated oncogene in breast cancer and may lead to an activation of the PI3K/AKT/mTOR-pathway. Cell lines resistant to tamoxifen have an activated PI3K-pathway. Phase III clinical trials show substantial benefit when mTOR-inhibitors are added to aromatase inhibitor treatment. On the other hand, patients with PIK3CA exon 20 mutation expression signature show better treatment outcome after adjuvant tamoxifen therapy. To address this controversy, we evaluated the PIK3CA mutation status in 1423 primary breast cancer specimens for its relationship with prognosis and treatment outcome after first-line endocrine treatment.

Methods: Hotspot mutations in exon 9 and 20 of PIK3CA were detected by multiplex snapshot analyses. Mutation status in ER-positive tumors was related to metastasis free survival (MFS) in 292 untreated lymph node negative (LNN) patients and time to progression (TTP) in patients with metastatic disease treated with first-line tamoxifen (N = 482) or aromatase inhibitors (AIs; N=103). Whole genome mRNA and miRs expression profiling was performed in the latter patient subset to develop a PIK3CA gene signature in 64 specimens. This was validated in 28 independent ER-positive specimens.

Results: We could evaluate 1371 specimens and detected 437 hotspot mutations for PIK3CA (32%). Mutations in exon 20 were detected in 256 patients (59%), of which 40 cases with a H1047L (16%) and 216 with a H1047R (84%) mutation. Mutations in PIK3CA exon 9 were discovered in 174 patients (41%), with E542K and E545K mutations in 59 (34%) and 105 (60%) cases, respectively, as the most prevalent ones. Finally, 6 patients had PIK3CA double mutations for both exon 9 and 20 and one patient had a E542K and E545K mutation.

Evaluation of the untreated LNN patients for prognosis showed no relationship between MFS and PIK3CA mutations (HR = 1.07 [95% CI: 0.73–1.56]; p = 0.73), neither for exon 9 nor exon 20 compared to wild-type. In the multicenter cohort of 482 patients with advanced disease treated with first-line tamoxifen no link with treatment outcome and PIK3CA mutation status was observed (HR = 1.13 [95% CI: 0.92–1.38]; p = 0.24). However, patients with advanced disease treated with first-line AIs (N = 64) showed a significant longer TTP for patients with a PIK3CA mutation compared to wild-types (HR = 0.46 [95% CI: 0.25–0.87]; p = 0.017).

Expression profiles of mRNAs and miRs were integrated and resulted in signatures for PIK3CA status discovered by pathway (17 genes) and expression analyses (10 genes and 9 miRs). Validation and comparison with published signatures in the 28 independent tumors showed that our 10-genes signature had the highest PIK3CA prediction accuracy (75%), with 60% sensitivity and 78% specificity. Moreover, this signature better associates with TTP (HR = 0.38 [95% CI: 0.20–0.72]; P = 0.003).

Conclusion: Mutations in PIK3CA are not prognostic value in untreated ER-positive LNN patients, not predictive in ER-positive patients with advanced disease treated with first-line tamoxifen therapy, however, are predictive for favourable outcome after first-line AIs. Moreover, we propose an expression signature of 10 genes as a putative biomarker to predict the PI3K status and response to AIs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P3-06-01.

Determining subcellular localization of novel drug targets by transient transfection in COS cells

Genomics-based approaches are increasingly being used to identify disease-associated genes that represent potential new drug targets. As a first step in the validation of genes of unknown function, we describe a method for rapidly determining the subcellular localization of the gene product. If an immunotherapeutic approach is being considered, it is of particular interest to identify targets that are either on the cell-surface or secreted. Transient expression in COS cells combined with immunofluorescent staining provides a semi-high throughput method for determining the subcellular localization of multiple targets in parallel. COS cells are ideal for this purpose since: (i) they transfect easily; (ii) the high levels of expression that can be achieved transiently allow detection after 24 h; and (iii) the relatively large size and spread morphology of these cells allows the subcellular organelles to be easily visualized. To evaluate the system, we show prototype staining patterns for known cytoplasmic,secreted, Golgi-associated, endoplasmic reticulum-associated, and plasma membrane proteins, as well as data for novel targets. The localization of novel secretory and cell-surface proteins as determined by immunofluorescent staining, was confirmed by independent methods.

Long-term control of vancomycin-resistant Enterococcus faecium at the scale of a large multihospital institution: a seven-year experience

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Long-term control of vancomycin-resistant Enterococcus faecium at the scale of a large multihospital institution: a seven-year experience

Repeated outbreaks of vancomycin-resistant Enterococcus faecium (VRE) occurred between 2004 and 2010 in Assistance Publique--Hôpitaux de Paris (AP-HP), a 23,000-bed multi-hospital institution. From August 2004 to December 2005, the French guidelines for preventing cross-transmission of multiresistant bacteria were applied. Because the number of VRE cases continued to increase, an institutional control programme was implemented from January 2006 onwards: it foresees stopping transfer of VRE and contact patients, separating VRE and contact patients in distinct cohorts, intervention of a central infection control team to support local teams, and quick application of measures as soon as first VRE cases are identified. Between August 2004 and December 2010, 45 VRE outbreaks occurred in 21 of the 38 AP-HP hospitals, comprising 533 cases. Time series analysis showed that the mean number of cases increased by 0.8 cases per month (95% confidence interval (CI): 0.3 to 1.3, p=0.001) before, and decreased by 0.7 cases per month after implementation of the programme (95% CI: -0.9 to -0.5, p<0.001), resulting in a significant trend change of -1.5 cases per month (95% CI: -2.1 to -0.9, p<0.001). The number of cases per outbreak was significantly lower after implementation of the programme. A sustained and coordinated strategy can control emerging bacteria at the level of a large regional multihospital institution.

Dynamic protein-DNA recognition: beyond what can be seen

Traditionally, specific DNA recognition is thought to rely on static contacts with the bases or phosphates. Recent results, however, indicate that residues far outside the binding context can crucially influence selectivity or binding affinity via transient, dynamic interactions with the DNA binding interface. These regions usually do not adopt a well-defined structure, even when bound to DNA, and thus form a fuzzy complex. Here, we propose the existence of a dynamic DNA readout mechanism, wherein distant segments modulate conformational preferences, flexibility or spacing of the DNA binding motifs or serve as competitive partners. Despite their low sequence similarity, these intrinsically disordered regions are often conserved at the structural level, and exploited for regulation of the transcription machinery via protein-protein interactions, post-translational modifications or alternative splicing.

Active site residue involvement in monoamine or diamine oxidation catalysed by pea seedling amine oxidase

The structures of copper amine oxidases from various sources show good similarity, suggesting similar catalytic mechanisms for all members of this enzyme family. However, the optimal substrates for each member differ, depending on the source of the enzyme and its location. The structural factors underlying substrate selectivity still remain to be discovered. With this in view, we examined the kinetic behaviour of pea seedling amine oxidase with cadaverine and hexylamine, the first bearing two, and the second only one, positively charged amino group. The dependence of K(m) and catalytic constant (k(c)) values on pH, ionic strength and temperature indicates that binding of the monoamine is driven by hydrophobic interactions. Instead, binding of the diamine is strongly facilitated by electrostatic factors, controlled by polar side-chains and two titratable residues present in the active site. The position of the docked substrate is also essential for the participation of titratable amino acid residues in the following catalytic steps. A new mechanistic model explaining the substrate-dependent kinetics of the reaction is discussed.

Independent validation of a prognostic genomic profile (ColoPrint) for stage II colon cancer (CC) patients

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Background: Adjuvant therapy is not routinely recommended for stage II CC patients but may be considered for high-risk patients. In this study we aim to independently validate a genomic profile that was developed to identify high-risk patients and can assist in treatment decisions.

Methods: An 18-gene profile had been developed using gene expression data from whole genome Agilent 44K oligonucleotide arrays and was validated in samples from an independent cohort of 206 CC patients and in in-silico datasets (Salazar et al. JCO 2010 in press). The profile was translated into a robust diagnostic test (ColoPrint) using customized 8-pack arrays. For this study, 233 patients who underwent curative resection (R0) for colon cancer stages II or III at the Klinikum rechts der Isar from 1987 to 2003 were selected. Fresh frozen tissues, clinical parameters and follow-up data for all patients were available. The samples were hybridized and the ColoPrint index was determined for all samples blinded from the clinical data.

Results: Patients in this study had a median age of 64 years and median follow-up of 97 months. The median number of resected lymph nodes was 21, giving an indirect measure of the quality of surgery. In the 135 stage II patients, ColoPrint identified most patients (73%) as low risk. The 5-year distant-metastasis free survival was 95% for low-risk patients and 80% for high-risk patients. In the univariate analysis, ColoPrint was the only significant parameter to predict the development of distant metastasis with a HR of 4.1 (95% CI 1.31-13.01, p=0.009). Using clinical parameters from the ASCO recommendation (T4, perforation, less than 12 LN assessed and/ or high grade) for the identification of high-risk patients was not significant (HR 2.3; 95% CI 0.68-7.53, p=0.18) and did not add power to the ColoPrint classification. These results are in good agreement with results from the first independent validation.

Conclusions: ColoPrint is able to predict the development of distant metastasis of stage II colon cancer patients and facilitates the identification of patients who may be safely managed without chemotherapy.

[Table: see text]

Integrated Genomic Profiling of Endocrine Therapy Response in Advanced Breast Cancer

PurposeIn hormone receptor positive breast cancer the response rates for endocrine treatment, i.e. tamoxifen (TAM) or aromatase inhibitors (AIs), are only 50 to 70% in the advanced disease setting. The overall aim of this retrospective study is to identify a molecular signature using integrated genomic profiling to improve prediction of endocrine treatment outcome in the advanced disease setting.ObjectivesA) To compare mRNA expression profiles of TAM- and AI-treated patients and to identify genes and pathways associated with treatment outcome.B) To discover miRNA and mRNA signatures predictive for AI response.Patients and MethodsFresh frozen Estrogen Receptor (ER)-positive primary breast cancer specimens from patients with advanced disease treated with first-line AIs (N=55) or TAM (N=109) were analyzed. Expression profiles of 670 miRNAs and 44K mRNAs were generated using multiplex qRT-PCR and microarrays. Profiles were related to clinical response and time to progression (TTP). Statistical and bio-informatic tools were applied to discover and combine markers into an integrated genomic predictive signature. The nearest centroid prediction method of BRB-ArrayTools (Version3.7.0) was used to assess the predictive value.ResultsThe quality controlled and informative expression profiles of 277 miRNAs and 14112 mRNAs in 50 AI-treated tumors and 10433 mRNAs in 101 TAM-treated tumors were included for further analysis in the discovery phase.Global testing of mRNAs linked to Biocarta pathways demonstrated the involvement of the interferon pathway in endocrine therapy response in both AI- and TAM-treated patients. Using BRB-ArrayTools survival analysis to find genes associated with TTP (P&lt;0.05), we identified 1002 mRNAs in AI-treated and 662 mRNAs in TAM-treated tumors to be significantly related with TTP.The overlap of 40 mRNAs between AI- and TAM-treatment was defined as a mRNA signature for endocrine treatment outcome. In TAM-treated patients this classifier has a 69% accuracy (63% sensitivity, 74% specificity), an odds ratio for clinical benefit of 4.69 (95% CI 1.99-11.05, P&lt;0.001) and a hazard ratio for TTP of 0.17 (95% CI 0.10-0.29, P&lt;0.001). In AI-treated patients, this 40mRNA signature has a performance of 78% accuracy (84% sensitivity, 62% specificity) and significantly predicts clinical benefit (odds ratio = 8.27, 95% CI 2.00-34.3, P=0.004) and TTP (hazard ratio = 0.07, 95% CI 0.02-0.22, P&lt;0.001).After statistical analysis a 16 miRNAs classifier for AI-treatment outcome was identified with a performance of 78% accuracy (89% sensitivity, 46% specificity). This classifier significantly predicts clinical benefit (Odds ratio = 7.07, 95% CI 1.57-31.9, P=0.011) and TTP (hazard ratio = 0.24, 95% CI 0.09-0.61, P=0.003).The genomic mRNA and miRNA signatures are currently integrated and validated in additional samples as well as “in silico” on tumors treated with neo-adjuvant AI (Miller et al, JCO 2009).ConclusionThis is the first study that combines miRNA and mRNA profiling in an attempt to define an integrated genomic signature for endocrine treatment outcome. Additional prospective multicenter studies are needed to confirm the predictive value of this signature.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3029.

Development and validation of a robust prognostic and predictive signature for colorectal cancer (CRC) patients

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Background: Between 25 and 35% of stage II CRC patients will experience a recurrence of their disease and may benefit from adjuvant chemotherapy. Official guidelines give suggestions but no clear recommendation for best risk stratification. Here we describe the development a robust signature that predicts disease relapse and can assist in treatment decisions. Methods: Fresh frozen tumor tissues from 180 patients with stage I, II and III colorectal cancer undergoing surgery were analyzed using high density Agilent 44K oligonucleotide arrays. Median FU was 70.2 months; 85% of patients did not receive adjuvant chemotherapy. Unsupervised hierarchical clustering based on full-genome gene expression measurement indicated the existence of 3 main colon molecular subclasses. Survival analysis of the 3 classes showed that subtype C (n= 27) had a poor outcome and subtype A (n= 48) good outcome. Only the intermediate group B (n=104) was used to develop a signature by using a cross validation procedure to score all genes for their association with 5-yr distant metastasis free survival (DMFS) and subsequently applied to all samples (n=180). The obtained gene signature was further validated on an independent cohort of 178 stage II + III colon samples. Results: A set of 38 prognosis related gene probes showed robust DMFS association in over 50% of all iterations in the Training Set of 180 samples. The gene signature was validated on an independent cohort of 178 samples from stage II + III colon cancer patients. The profile classified 61% of the validation samples as low-risk and 39% as high-risk. The low- and high-risk samples showed a significant difference in DMFS with a HR of 3.19 (P= 8.5e-4). Five-year DMFS rates were 89% (95%CI 83–95) for low-risk and 62% (95%CI 50–77) for high-risk samples. Moreover, the profile showed a significant performance within stage II (P=0.0058) and III (P=0.036) only samples. The performance of the profile was significant for both untreated (P=0.0082) and treated patients (P=0.016) suggesting that its power is independent of treatment benefits. Conclusions: ColoPrint is able to predict the prognosis of stage II and III colon cancer patients and facilitates the identification of patients who would benefit from adjuvant chemotherapy.

[Table: see text]

EPIC-DB: a proteomics database for studying Apicomplexan organisms

Background

High throughput proteomics experiments are useful for analyzing the protein expression of an organism, identifying the correct gene structure of a genome, or locating possible post-translational modifications within proteins. High throughput methods necessitate publicly accessible and easily queried databases for efficiently and logically storing, displaying, and analyzing the large volume of data.

Description

EPICDB is a publicly accessible, queryable, relational database that organizes and displays experimental, high throughput proteomics data for Toxoplasma gondii and Cryptosporidium parvum. Along with detailed information on mass spectrometry experiments, the database also provides antibody experimental results and analysis of functional annotations, comparative genomics, and aligned expressed sequence tag (EST) and genomic open reading frame (ORF) sequences. The database contains all available alternative gene datasets for each organism, which comprises a complete theoretical proteome for the respective organism, and all data is referenced to these sequences. The database is structured around clusters of protein sequences, which allows for the evaluation of redundancy, protein prediction discrepancies, and possible splice variants. The database can be expanded to include genomes of other organisms for which proteome-wide experimental data are available.

Conclusion

EPICDB is a comprehensive database of genome-wide T. gondii and C. parvum proteomics data and incorporates many features that allow for the analysis of the entire proteomes and/or annotation of specific protein sequences. EPICDB is complementary to other -genomics- databases of these organisms by offering complete mass spectrometry analysis on a comprehensive set of all available protein sequences.

Substrate preference of transglutaminase 2 revealed by logistic regression analysis and intrinsic disorder examination

Tissue transglutaminase (TG2) catalyzes the Ca(2+)-dependent posttranslational modification of proteins via formation of isopeptide bonds between their glutamine and lysine residues. Although substrate specificity of TG2 has been studied repeatedly at the sequence level, no clear consensus sequences have been determined so far. With the use of the extensive structural information on TG2 substrate proteins listed in TRANSDAB Wiki database, a slight preference of TG2 for glutamine and lysine residues situated in turns could be observed. When the spatial environment of the favored glutamine and lysine residues was analyzed with logistic regression, the presence of specific amino acid patterns was identified. By using the occurrence of the predictor amino acids as selection criteria, several polypeptides were predicted and later identified as novel in vitro substrates for TG2. By studying the sequence of TG2 substrate proteins lacking available crystal structure, the strong favorable influence on substrate selection of the presence of substrate glutamine and lysine residues in intrinsically disordered regions could also be revealed. The collected structural data have provided novel understanding of how this versatile enzyme selects its substrates in various cell compartments and tissues.

[Experimental nephrology unit: overview and research projects]

After a short historical background of the Laboratory, the main research topics--renal toxicology, physiopathology of renal interstitial fibrosis and hormonology--are described in the perspective of a partnership between research clinicians and full time scientists. National as well as international scientific collaborations underline the need of combining expertises, stimulating also the training of youngest colleagues to the experimental approach of their future discipline.