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Publication
Journal: Cytometry Part A
December/12/2004
Abstract
BACKGROUND
Most biological samples are cell mixtures. Some basic questions are still unanswered about analyzing these heterogeneous samples using gene expression microarray technology (MAT). How meaningful is a cell mixture's overall gene expression profile (GEP)? Is it necessary to purify the cells of interest before microarray analysis, and how much purity is needed? How much does the purification itself distort the GEP, and how well can the GEP of a small cell subset be recovered?
METHODS
Model cell mixtures with different cell ratios were analyzed by both spotted and Affymetrix MAT. GEP distortion during cell purification and GEPs of purified cells were studied. CD34+ cord blood cells were purified and analyzed by MAT.
RESULTS
GEPs for mixed cell populations were found to mirror the cell ratios in the mixture. Over 75% pure samples were indistinguishable from pure cells by their overall GEP. Cell purification preserved the GEP. The GEPs of small cell subsets could be accurately recovered by cell sorting both from model cell mixtures and from cord blood.
CONCLUSIONS
Purification of small cell subsets from a mixture prior to MAT is necessary for meaningful results. Even completely hidden GEPs of small cell subpopulations can be recovered by cell sorting.
Publication
Journal: Clinical Cancer Research
September/7/2008
Abstract
Changes in global gene expression patterns in tumor cells following in vivo therapy may vary by treatment and provide added or synergistic prognostic power over pretherapy gene expression profiles (GEP). This molecular readout of drug-cell interaction may also point to mechanisms of action/resistance. In newly diagnosed patients with multiple myeloma (MM), microarray data were obtained on tumor cells prior to and 48 hours after in vivo treatment using dexamethasone (n = 45) or thalidomide (n = 42); in the case of relapsed MM, microarray data were obtained prior to (n = 36) and after (n = 19) lenalidomide administration. Dexamethasone and thalidomide induced both common and unique GEP changes in tumor cells. Combined baseline and 48-hour changes in GEP in a subset of genes, many related to oxidative stress and cytoskeletal dynamics, were predictive of outcome in newly diagnosed MM patients receiving tandem transplants. Thalidomide-altered genes also changed following lenalidomide exposure and predicted event-free and overall survival in relapsed patients receiving lenalidomide as a single agent. Combined with baseline molecular features, changes in GEP following short-term single-agent exposure may help guide treatment decisions for patients with MM. Genes whose drug-altered expression were found to be related to survival may point to molecular switches related to response and/or resistance to different classes of drugs.
Publication
Journal: Expert Review of Gastroenterology and Hepatology
December/9/2012
Abstract
Gastroenteropancreatic neuroendocrine tumors (GEP-NET) are a heterogeneous group of neoplasms that arise from neuroendocrine cells of the GI tract and pancreas. Due to the lack of symptoms in the early stage of the disease and the frequency of nonspecific gastrointestinal symptoms, GEP-NET are difficult to diagnose. This delay in diagnosis often results in patients presenting with advanced disease and thus a poor prognosis. There is an unmet medical need for earlier, more definitive GEP-NET diagnosis. Identification of effective biomarkers to improve GEP-NET diagnosis, as well as to assess treatment efficacy, relapse and prognosis, is important for improving outcomes in GEP-NET. Chromogranin A is currently the most useful general biomarker for the assessment of GEP-NET. This review summarizes the biochemical characteristics of chromogranin A, its specificity and sensitivity for GEP-NET diagnosis, and its use in monitoring treatment effectiveness, disease progression and prognosis.
Publication
Journal: PLoS ONE
August/22/2011
Abstract
BACKGROUND
A large number of gene expression profiling (GEP) studies on prognosis of colorectal cancer (CRC) has been performed, but no reliable gene signature for prediction of CRC prognosis has been found. Bioinformatic enrichment tools are a powerful approach to identify biological processes in high-throughput data analysis.
RESULTS
We have for the first time collected the results from the 23 so far published independent GEP studies on CRC prognosis. In these 23 studies, 1475 unique, mapped genes were identified, from which 124 (8.4%) were reported in at least two studies, with 54 of them showing consisting direction in expression change between the single studies. Using these data, we attempted to overcome the lack of reproducibility observed in the genes reported in individual GEP studies by carrying out a pathway-based enrichment analysis. We used up to ten tools for overrepresentation analysis of Gene Ontology (GO) categories or Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways in each of the three gene lists (1475, 124 and 54 genes). This strategy, based on testing multiple tools, allowed us to identify the oxidative phosphorylation chain and the extracellular matrix receptor interaction categories, as well as a general category related to cell proliferation and apoptosis, as the only significantly and consistently overrepresented pathways in the three gene lists, which were reported by several enrichment tools.
CONCLUSIONS
Our pathway-based enrichment analysis of 23 independent gene expression profiling studies on prognosis of CRC identified significantly and consistently overrepresented prognostic categories for CRC. These overrepresented categories have been functionally clearly related with cancer progression, and deserve further investigation.
Publication
Journal: Histochemistry
June/18/1984
Abstract
The pancreas and gastrointestinal tract (GIT) of adults and of an embryonic stage of 11 cm long (about half the length of newborn fish) of the spiny dogfish, Squalus acanthias, were investigated immunocytochemically for the occurrence of the gastro-entero-pancreatic (GEP) neurohormonal peptides. In the pancreas of adult forms 5 endocrine cell types were seen, namely insulin-, somatostatin-, glucagon-, pancreatic polypeptide (PP)- and gastric inhibitory peptide (GIP)-immunoreactive cells. These cell types form scattered islets and were seen sometimes to surround small ducts. GIP-immunoreactivity cells did not occur in glucagon-containing cells. In the mucosa of GIT of adults 18 endocrine cell types were observed, viz. insulin-, somatostatin-, glucagon-, glicentin, PP-, polypeptide YY (PYY)-, vasoactive intestinal polypeptide (VIP)-, GIP-, gastrin C-terminus, CCK-, neurotensin N-terminus-, bombesin/gastrin releasing peptide (GRP)-, substance P-, enkephalin-, alpha-endorphin, beta-endorphin-, serotonin- and calcitonin immunoreactive cells. These cells occurred mostly in the intestine. All these cell types were of the open type, except glucagon- and glicentin-immunoreactive cells in the stomach, which seemed to be of the closed type. In the muscle layers and the submucosa, VIP and substance P- immunoreactive nerves and neurons were observed. In the pancreas of the dogfish embryo only 3 endocrine cell types could be demonstrated, namely insulin-, somatostatin- and glucagon-immunoreactive cells. In the mucosa of the GIT of the embryos studied 12 endocrine cell types were detected, viz. insulin-, somatostatin-, glucagon-, PP-, PYY-, VIP, GIP, gastrin C-terminus-, CCK-, neurotensin N-terminus-, enkephalin- and serotonin immunoreactive cells. The number of these cells, except that of PYY-immunoreactive cells, was lower than that of adults and in some cases their distribution did not correspond with that of adults.
Authors
Publication
Journal: Journal of Thoracic Disease
August/22/2012
Abstract
For patients with identical clinical-pathological characteristics or the same stage of lung cancer, great uncertainties remain regarding how some patients will be cured while other patients will have cancer recurrence, metastasis, or death after surgical resection. Identification of patients at high risk of recurrence, those who are unlikely to respond to specific chemotherapeutic agents, is the rationale for measuring specific biochemical markers. Thus, main investigational studies nowadays are focused in identifying molecular markers of recurrence, beyond pathologic stage, after surgical treatment and factors that can predict a benefit from adjuvant chemotherapy in poor prognosis subgroups, to individualize treatments. Advances in genomics and proteomics have generated many candidate markers with potential clinical value. Gene expression profiling (GEP) by microarray or real-time quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) can be useful in the classification or prognosis of various types of cancer, including lung cancer. A number of prognostic gene expression signatures have been reported to predict survival in non-small cell lung cancer (NSCLC). In this review, we focus on the role of GEP in early-stage NSCLC as predictive and prognostic biomarker and its potential use for a 'personalized' medicine in the years to come.
Publication
Journal: Technology in Cancer Research and Treatment
July/29/2010
Abstract
The large amounts of microarray data provide us a great opportunity to identify gene expression profiles (GEPs) in different tissues or disease states. Disease-specific biomarker genes likely share GEPs that are distinct in disease samples as compared with normal samples. The similarity of the GEPs may be evaluated by Pearson Correlation Coefficient (PCC) and the distinctness of GEPs may be assessed by Kolmogorov-Smirnov distance (KSD). In this study, we used the PCC and KSD metrics for GEPs to identify disease-specific (cancer-specific) biomarkers. We first analyzed and compared GEPs using microarray datasets for smoking and lung cancer. We found that the number of genes with highly different GEPs between comparing groups in smoking dataset was much larger than that in lung cancer dataset; this observation was further verified when we compared GEPs in smoking dataset with prostate cancer datasets. Moreover, our Gene Ontology analysis revealed that the top ranked biomarker candidate genes for prostate cancer were highly enriched in molecular function categories such as 'cytoskeletal protein binding' and biological process categories such as 'muscle contraction'. Finally, we used two genes, ACTC1 (encoding an actin subunit) and HPN (encoding hepsin), to demonstrate the feasibility of diagnosing and monitoring prostate cancer using the expression intensity histograms of marker genes. In summary, our results suggested that this approach might prove promising and powerful for diagnosing and monitoring the patients who come to the clinic for screening or evaluation of a disease state including cancer.
Publication
Journal: Theranostics
November/3/2014
Abstract
Gastroenteropancreatic neuroendocrine neoplasms are heterogeneous in their clinical behavior and require therapies specially tailored according to staging, grading, origin and expression of peptide receptors. Despite extensive scientific efforts, the therapy options are still not satisfactory. The main reasons are due to the lack of a broad mechanistic knowledge, an insufficient classification of specific diagnostic sub-groups, and predictive markers. GEP-NEN tumors evade early diagnosis because of slow asymptomatic growth behavior and are frequently not detected until metastasized. How signaling networks contribute to tumor progression and how these networks interact remains unclear in large parts. In this review we summarize the knowledge on the growth factor responsive non-angiogenetic pathways in sporadic GEP-NENs, highlight promising mechanistic research approaches, and describe important therapy targets.
Publication
Journal: Clinical Cancer Research
June/26/2017
Abstract
Purpose: Fluorine-18 fluorodeoxyglucose positron emission tomography with CT attenuation correction (18F-FDG PET/CT) is useful in the detection and enumeration of focal lesions and in semiquantitative characterization of metabolic activity (glycolytic phenotype) by calculation of glucose uptake. Total lesion glycolysis (TLG) and metabolic tumor volume (MTV) have the potential to improve the value of this approach and enhance the prognostic value of disease burden measures. This study aims to determine whether TLG and MTV are associated with progression-free survival (PFS) and overall survival (OS), and whether they improve risk assessments such as International Staging System (ISS) stage and GEP70 risk.Experimental Design: 192 patients underwent whole body PET/CT in the Total Therapy 3A (TT3A) trial and were evaluated using three-dimensional region-of-interest analysis with TLG, MTV, and standard measurement parameters derived for all focal lesions with peak SUV above the background red marrow signal.Results: In multivariate analysis, baseline TLG>> 620 g and MTV>> 210 cm3 remained a significant factor of poor PFS and OS after adjusting for baseline myeloma variables. Combined with the GEP70 risk score, TLG>> 205 g identifies a high-risk-behaving subgroup with poor expected survival. In addition, TLG>> 205 g accurately divides ISS stage II patients into two subgroups with similar outcomes to ISS stage I and ISS stage III, respectively.Conclusions: TLG and MTV have significant survival implications at baseline and offer a more precise quantitation of the glycolytic phenotype of active disease. These measures can be assessed more readily than before using FDA-approved software and should be standardized and incorporated into clinical trials moving forward. Clin Cancer Res; 23(8); 1981-7. ©2016 AACR.
Publication
Journal: British Journal of Cancer
March/9/2014
Abstract
BACKGROUND
Gastroenteropancreatic neuroendocrine tumours (GEP-NETs) are heterogeneous with respect to biological behaviour and prognosis. As angiogenesis is a renowned pathogenic hallmark as well as a therapeutic target, we aimed to investigate the prognostic and clinico-pathological role of tissue markers of hypoxia and angiogenesis in GEP-NETs.
METHODS
Tissue microarray (TMA) blocks were constructed with 86 tumours diagnosed from 1988 to 2010. Tissue microarray sections were immunostained for hypoxia inducible factor 1α (Hif-1α), vascular endothelial growth factor-A (VEGF-A), carbonic anhydrase IX (Ca-IX) and somatostatin receptors (SSTR) 1-5, Ki-67 and CD31. Biomarker expression was correlated with clinico-pathological variables and tested for survival prediction using Kaplan-Meier and Cox regression methods.
RESULTS
Eighty-six consecutive cases were included: 51% male, median age 51 (range 16-82), 68% presenting with a pancreatic primary, 95% well differentiated, 51% metastatic. Higher grading (P=0.03), advanced stage (P<0.001), high Hif-1α and low SSTR-2 expression (P=0.03) predicted for shorter overall survival (OS) on univariate analyses. Stage, SSTR-2 and Hif-1α expression were confirmed as multivariate predictors of OS. Median OS for patients with SSTR-2+/Hif-1α-tumours was not reached after median follow up of 8.8 years, whereas SSTR-2-/Hif-1α+ GEP-NETs had a median survival of only 4.2 years (P=0.006).
CONCLUSIONS
We have identified a coherent expression signature by immunohistochemistry that can be used for patient stratification and to optimise treatment decisions in GEP-NETs independently from stage and grading. Tumours with preserved SSTR-2 and low Hif-1α expression have an indolent phenotype and may be offered less aggressive management and less stringent follow up.
Publication
Journal: European Journal of Endocrinology
April/23/2015
Abstract
Neuroendocrine tumors from gastro-pancreatic origin (GEP-NET) can be responsible for liver metastases. Such metastases can be the dominant part of the disease as well due to the tumor burden itself or the symptoms related to such liver metastases. Intra-arterial therapies are commonly used in liver only or liver-dominant disease and encompass trans-arterial chemoembolization (TACE), trans-arterial embolization (TAE), and radioembolization (RE). TACE performed with drug emulsified in Lipiodol has been used for the past 20 years with reported overall survival in the range of 3-4 years, with objective response up to 75%. Response to TACE is higher when treatment is used as a first-line therapy and degree of liver involvement is lower. Benefit of TACE over TAE is unproven in randomized study, but reported in retrospective studies namely in pancreatic NETs. RE provides early interesting results that need to be further evaluated in terms of benefit and toxicity. Radiofrequency ablation allows control of small size and numbered liver metastases, with low invasiveness. Ideal metastases to target are one metastasis <5 cm, or three metastases <3 cm, or a sum of diameter of all metastases below 8 cm. Ablation therapies can be applied in the lung or in the bones when needed, and more invasive surgery should be probably saved for large-size metastases. Even if the indication of image-guided therapy in the treatment of GEP-NET liver metastases needs to be refined, such therapies allow for manageable invasive set of treatments able to address oligometastatic patients in liver, lung, and bones. These treatments applied locally will save the benefit and the toxicity of systemic therapy for more advanced stage of the disease.
Publication
Journal: Cancer Imaging
January/8/2007
Abstract
Neuroendocrine tumours (NETs) are often thought to be rare and rather recherché cancers which are of little concern to the general physician, surgeon or radiologist because of their rarity and esoteric nature. In fact, while relatively uncommon, the total group of gastro-entero-pancreatic (GEP) tumours incorporates the spectrum of all types of carcinoids, including bronchial carcinoids, and the whole gamut of islet-cell tumours. Some of these may present as functioning tumours, with a plethora of hormonal secretions and concomitant clinical syndromes, and GEPs in general have an incidence around 30 per million population per year. This means that in the whole European Union, for example, there will be in the region of 12,000 new patients every year presenting with one or another manifestation of these tumours. Furthermore, the comparatively long survival of many of these patients, compared to more common adenocarcinomas or epithelial tumours, implies that the point prevalence is also not inconsiderable. However, it is undoubtedly true that these tumours can be difficult to identify, especially in their early stages, and it is then that radiological investigation becomes of paramount importance. Having taken into account all these considerations, most investigators would initiate investigation of a suspected or biochemically proven islet-cell tumour with cross-sectional imaging-either CT or MRI. This will clearly identify the larger lesions, allow assessment of the entire abdomen, and provide valuable information on the presence of hepatic metastates.
Publication
Journal: International Journal of Oncology
January/24/2011
Abstract
To improve the prognosis of advanced esophageal cancer, neoadjuvant chemotherapy (NACT) followed by surgery is a promising treatment strategy. NACT has been shown to improve the prognosis of responders. However, non-responders not only suffer from side-effects, but they also lose precious time to take advantage of other possible treatments. Therefore, it is crucial to establish a reliable method that allows prediction of response before chemotherapy. A biopsy sample can provide valuable information on the biological characteristics of an individual esophageal cancer, which can affect chemosensitivity. Comprehensive gene expression profiling (GEP) using oligonucleotide microarray covering 30,000 human probes was performed in 50 pretreatment endoscopic biopsy samples from 25 patients with esophageal squamous cell cancer (ESCC) who underwent cisplatin-based chemotherapy (two samples per patient). Chemotherapeutic responses were evaluated by the reduction rate of the tumor area on CT scans. Responders were defined as patients with reduction rates of ≥50% and non-responders were defined as patients with <50% decrease. The diagnostic system, that predicts responses to chemotherapy, was constructed with the 199 most informative genes, and showed 82% of accuracy. Furthermore, the predictive performance of this system was confirmed using an additional ten samples with an accuracy of 80%. This study shows that GEP of pretreatment ESCC biopsy samples has the potential to predict responses to chemotherapy.
Publication
Journal: Endocrine-Related Cancer
March/24/2012
Abstract
Somatostatin (SS) and dopamine (DA) receptors have been highlighted as two critical regulators in the negative control of hormonal secretion in a wide group of human endocrine tumors. Both families of receptors belong to the superfamily of G protein-coupled receptors and share a number of structural and functional characteristics. Because of the generally reported high expression of somatostatin receptors (SSTRs) in neuroendocrine tumors (NET), somatostatin analogs (SSA) have a pronounced role in the medical therapy for this class of tumors, especially pituitary adenomas and well-differentiated gastroenteropancreatic NET (GEP NET). Moreover, NET express not only SSTR but also frequently dopamine receptors (DRs), and DA agonists targeting the D(2) receptor (D(2)) have been demonstrated to be effective in controlling hormone secretion and cell proliferation in in vivo and in vitro studies. The treatment with SSAs combined with DA agonists has already been demonstrated efficacious in a subgroup of patients with GH-secreting pituitary adenomas and few reported cases of carcinoids. The recent availability of new selective and universal SSA and DA agonists, as well as the chimeric SS/DA compounds, may shed new light on the potential role of SSTR and D(2) as combined targets for biotherapy in NET. This review provides an overview of the latest studies evaluating the expression of SSTR and DR in NET, focusing on their co-expression and the possible clinical implications of such co-expression. Moreover, the most recent insights in SSTR and D(2) pathophysiology and the future perspectives for treatment with SSA, DA agonists, and SS/DA chimeric compounds are discussed.
Publication
Journal: Theranostics
June/19/2020
Abstract
Immune-checkpoint blockades (ICBs) have been routinely implemented to treat metastatic urothelial cancer (mUC), whereas robust biomarkers are urgently warranted. Herein, we explored latent promising biomarkers based on 348 pretreatment mUC samples from IMvigor210. Methods: The genome, transcriptome, immunome, and metabolome were systemically analyzed using the external TCGA dataset for validation. Kaplan-Meier and ROC curve analyses were performed to estimate the predictive capacity of M1-macrophage infiltration. Chi-square/Spearman/Mann Whitney U test are used to determine its correlation to genetic, biochemical, and clinicopathological parameters. Results: M1 frequency is a robust biomarker for predicting the prognosis and response to ICBs, which is non-inferior to tumor mutation burden (TMB) or tumor neoantigen burden (TNB), and exceeds CD8 T cells, T cell inflamed gene expression profile (GEP), and PD-L1 expression. Moreover, M1 infiltration is associated with immune phenotypes (AUC = 0.785) and is negatively correlated with immune exclusion. Additionally, transcriptomic analysis showed immune activation in the high-M1 subgroup, whereas it showed steroid and drug metabolism reprograming in the M1-deficient subset, which characterized the limited sensitivity to ICB therapy. Notably, investigation of the corresponding intrinsic genomic profiles highlighted the significance of TP53 and FGFR alterations. Conclusions: M1 infiltration is a robust biomarker for immunotherapeutic response and immunophenotype determination in an mUC setting. Innate immunity activation involving macrophage polarization remodeling and anti-FGFR mutations may be promising strategies for synergy with anti-PD-L1 treatments and may help prolong the clinical survival of patients with mUC.
Keywords: immune checkpoint blockade; immunophenotype; macrophage; urothelial cancer.
Publication
Journal: PLoS ONE
February/4/2014
Abstract
Multiple myeloma (MM) is characterized by complex genetic abnormalities whose complexity signifies varying degree of chromosomal instability (CIN). In this study, we introduced a novel CIN measure, chromosome instability genome event count (CINGEC), which considered both copy number aberrations and interstitial breakpoints from high-resolution genome-wide assays. When assessed in two aCGH MM datasets, higher CINGEC was associated with poor survival. We then derived a CINGEC-associated gene expression profile (GEP) signature, CINGECS, using a dataset that has both aCGH and GEP. Genes in CINGECS were mainly involved in DNA damage responses besides in aneuploidy and other generic oncogenic processes contrary to other CIN associated GEP signatures. Finally, we confirmed its survival association in three GEP datasets that encompassed newly diagnosed patients treated with transplant-based protocol with or without novel agents for induction as well as relapsed patients treated with bortezomib. Furthermore, CINGECS was independent of many GEP-based prognostic signatures. In conclusion, our novel CIN measure has definite biological and clinical significance in myeloma.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
December/8/2002
Abstract
The Rab3 GDP/GTP exchange protein (Rab3 GEP) activates the Rab3 small GTP-binding protein (G protein) family, including Rab3A that is an important member controlling synaptic vesicle trafficking. Here, we examined the role of Rab3 GEP in regulating neurotransmitter release in autapses of mouse hippocampal neurons in culture. The release probability was markedly reduced in Rab3 GEP-/- neurons, whereas the readily releasable pool size was not different between WT and Rab3 GEP-/- neurons, indicating that Rab3 GEP up-regulates a postdocking step of synaptic exocytosis. Because Rab3A reportedly down-regulates Ca(2+)-triggered fusion of synaptic vesicles, these results provide evidence for a role of Rab3 GEP in the postdocking process distinct from Rab3A activation.
Publication
Journal: Investigative Ophthalmology and Visual Science
May/26/2011
Abstract
OBJECTIVE
To evaluate with the use of corneal topographic data the differences between total corneal power calculated using ray tracing (TCP) and the Gaussian formula (GEP) in normal eyes, eyes that previously underwent laser in situ keratomileusis/photorefractive keratectomy (LASIK/PRK), and theoretical models.
METHODS
TCP and GEP using mean instantaneous curvature were calculated over the central 4-mm zone in 94 normal eyes, 61 myopic-LASIK/PRK eyes, and 9 hyperopic-LASIK/PRK eyes. A corneal model was constructed to assess the incident angles at the posterior corneal surface for both refracted rays and parallel rays. Corneal models with varying parameters were also constructed to investigate the differences between mean TCP and GEP (4-mm zone), and an optical design software validation was performed.
RESULTS
The TCP values tended to be less than GEP in normal and myopic-LASIK/PRK eyes, with the opposite relationship in some hyperopic-LASIK/PRK eyes having the highest anterior surface curvature. The difference between TCP and GEP was a function of anterior surface instantaneous radii of curvature and posterior/anterior ratio in postrefractive surgery eyes but not in normal eyes. In model corneas, posterior incident angles with parallel rays were greater than those with refracted rays, producing an overestimation of negative effective posterior corneal power; differences in magnitude between TCP and GEP increased with decreasing ratio of posterior/anterior radii of curvature, consistent with clinical results.
CONCLUSIONS
In eyes after refractive surgery, calculating posterior corneal power using the Gaussian formula and its paraxial assumptions introduces errors in the calculation of total corneal power. This may generate errors in intraocular lens power calculation when using the Gaussian formula after refractive surgery.
Publication
Journal: GMS German Medical Science
February/21/2010
Abstract
Nowadays, drug research and surveillance after authorisation becomes more and more important for several reasons. Non-interventional studies (NIS) investigate various aspects of drug use including efficacy and safety under real life conditions. Such kind of health services research should be on a high scientific, methodological and organisational level. Therefore accompanying measures to improve or to keep the quality are highly recommended. The aim of quality management is: first to avoid bias of results by using an appropriate study design and an adequate data analysis, second to assure authenticity, completeness and validity of the data and third to identify and resolve deficiencies at an early stage. Basic principles are laid down in corresponding guidelines and recommendations of authorities, institutes and societies. Various guidelines for good epidemiological practice (GEP) were published by the U.S. Food and Drug Administration (FDA) and international and regional societies for epidemiology. In addition in Germany the Federal Institute for Drugs and Medical Devices (BfArM) together with the Paul Ehrlich Institute (PEI) and the German Association of Research-Based Pharmaceutical Companies (VFA) have published respectively recommendations dealing with quality aspects of non-interventional observational studies. Key points are the advanced publishing of information about the project, developing of a study plan/protocol containing the scientific objectives, a sample size justification and a description of the planned analyses and the publishing of a summary of the results timely after completion of the study. The quality of the data can be improved by using standardized case report forms (CRF) and the CRF should be reviewed and tested before start of study by some participants. A source data verification (SDV) should be performed in randomly selected centres - in between 2% and 5% of the centres depending on the number of participating centres. Before start of statistical analysis a statistical analysis plan (SAP) should be created. The use of standardized tables and figures is highly recommended. The basis of the report writing should be the STROBE-statement "Strengthening the Reporting of Observational studies in Epidemiology Initiative" containing a checklist of 22 points to be covered in the report. The development of own standard operating procedures (SOP) describing the processes during planning, conduct and evaluation of a non-interventional study as well as the quality management and the regular training of all involved people is also highly recommended. All accompanying measures to improve or to keep the quality of the NIS should not violate the concept of non-intervention.
Publication
Journal: Arzneimittel-Forschung
October/25/2004
Abstract
OBJECTIVE
The purpose of the study was to evaluate the therapeutic efficacy and safety of long-term complementary therapy in primary, non-metastatic mammary carcinoma patients in UICC stage I-III with a standardized European mistletoe extract (Viscum album L., Iscador, "mistletoe extract") given in addition to conventional adjuvant oncologic therapy (i.e. chemo-, radio-, and hormonal therapy; "conventional therapy").
METHODS
The multicenter, comparative, retrolective, pharmaco-epidemiological cohort study with parallel groups design and randomly selected centers was carried out according to Good Epidemiological Practice (GEP) rules. The test group patients received subcutaneous mistletoe extract injections for at least three months in addition to the conventional therapy, while the control group was treated with conventional therapy only. The patients were followed up for at least three years or until death. The primary endpoint for efficacy was the overall incidence of adverse drug reactions (ADRs) attributed to the conventional therapy. Secondary endpoints were symptoms associated with disease and treatment, as well as the survival. All end-points were adjusted to baseline imbalance, therapy regimen and other confounders by the logistic regression or the Cox proportional hazard regression. Safety was assessed by the number of patients with ADRs attributed to the mistletoe extract treatment, the ADR severity and the evaluation of a possible tumor enhancement.
RESULTS
1442 patients (710 tests and 732 controls) were eligible for the "per protocol" analysis of efficacy and safety. At baseline, the mistletoe extract group had a more advanced disease and worse prognostic factors profile. After a median follow up of 67 vs. 61 months, and a median mistletoe extract therapy duration of 52 months, significantly fewer test group patients (16.3%) than control patients (54.1%) developed one or more ADRs attributed to the conventional therapy (adjusted odds ratio (95% confidence interval, CI): OR = 0.47 (0.32-0.67), p < 0.001). In the mistletoe extract group, several symptoms more frequently disappeared, and the overall estimated survival was significantly longer (adjusted mortality hazard ratio (95% CI): HR = 0.46 (0.22-0.96), p = 0.038). Systemic ADRs attributed to the mistletoe extract treatment developed 0.8%, and local ADRs 17.3% of the patients. The ADR severity was mild to intermediate (WHO/CTC grade 1-2). Severe mistletoe extract therapy-related ADRs or tumor enhancement were not observed.
CONCLUSIONS
The results of the present study confirmed the safety of the complementary therapy of patients with primary, non-metastatic mammary carcinoma with a standardized mistletoe extract and showed considerably fewer ADRs attributed to concurrent conventional therapy, as well as reduced disease and treatment-associated symptoms, and suggested a prolonged overall survival in the mistletoe extract group as compared with controls.
Publication
Journal: Journal of Biological Chemistry
June/20/2005
Abstract
The cellular positive transcription elongation factor b (P-TEFb), containing cyclin T1 and cyclin-dependent kinase 9 (CDK9), interacts with the human immunodeficiency virus, type 1 (HIV-1) regulatory protein Tat to enable viral transcription and replication. Cyclin T1 is an unusually long cyclin and is engaged by cellular regulatory proteins. Previous studies showed that the granulin/epithelin precursor (GEP) binds the histidine-rich region of cyclin T1 and inhibits P-TEFb function. GEP is composed of repeats that vary in sequence and properties. GEP also binds directly to Tat. Here we show that GEP and some of its constituent granulin repeats can inhibit HIV-1 transcription via Tat without directly binding to cyclin T1. The interactions of granulins with Tat and cyclin T1 differ with respect to their binding sites and divalent cation requirements, and we identified granulin repeats that bind differentially to Tat and cyclin T1. Granulins DE and E bind Tat but do not interact directly with cyclin T1. These granulins are present in complexes with Tat and P-TEFb in which Tat forms a bridge between the cellular proteins. Granulins DE and E repress transcription from the HIV-1 LTR and gene expression from the viral genome, raising the possibility of developing granulin-based inhibitors of viral infection.
Publication
Journal: World Journal of Surgery
January/6/2015
Abstract
BACKGROUND
Neuroendocrine neoplasias (NEN) of the gastroenteropancreatic (GEP) system frequently present with metastatic deposits. The proliferation marker Ki-67 is used for diagnosis and to assess the prognosis of disease. The aim of our study was to evaluate the usefulness of Ki-67 % in the assessment of NEN patients with regard to their disease stage in clinical practice. Additionally, a comparative analysis of Ki-67 levels among different sites of disease was performed.
METHODS
This retrospective study included patients with GEP NEN referred to our center from 2010 to 2012. The NEN diagnosis was confirmed by standard histopathology. Ki-67 immunohistochemistry was done on paraffin-embedded sections using an automated Leica immunohistochemistry machine. NEN grading was carried out according to European Neuroendocrine Tumor Society recommendations (low grade [G1] to intermediate grade [G2], well to moderately differentiated neuroendocrine neoplasms; high-grade [G3], moderately to poorly differentiated neuroendocrine neoplasms). Results of tumor staging and grading were correlated. In a subgroup of cases, comparative analysis of Ki-67 levels in different sites of disease was carried out.
RESULTS
One hundred sixty-one GEP NEN patients were included in the study. Metastatic disease was seen in 46.1 % (53/115) of G1 tumors, 77.8 % (28/36) of G2 tumors, and 100 % of (10/10) G3 tumors (p = 0.0002). When stratified according to primary tumor site, metastatic disease was documented in 42.9 % (36/84) of patients with pancreatic NEN and in 91.9 % (34/37) of those with small intestinal primary. Stage IV metastatic disease was present in 27.8 % (32/115) and 72.2 % (26/36) of the G1 and G2 tumors, respectively, and in 90 % (9/10) of the G3 tumors. Assessment of the Ki-67 index for a subset of cases at metastatic sites as well as the primary tumor site showed discrepancies in 35.3 % cases. In 7/9 (77.8 %) patients with liver metastases, Ki-67 % was higher in the liver lesions than in the primary tumor.
CONCLUSIONS
Patients with GEP NEN exhibiting a high Ki-67 proliferation index present with metastatic disease in the vast majority of cases. Depending upon the primary tumor site, metastases are to be expected also in tumors with low Ki-67 %, although they are considered less aggressive. Different disease sites may express heterogeneous Ki-67 levels.
Publication
Journal: Journal of Biological Chemistry
January/25/1999
Abstract
The Rab3 small G protein subfamily (Rab3) consists of four members, Rab3A, -B, -C, and -D. We have recently isolated and characterized the Rab3 regulators, GDP/GTP exchange protein (GEP) and GTPase activating protein (GAP), both of which are specific for the Rab3 subfamily. Rab3 GEP stimulates the conversion of the GDP-bound inactive form to the GTP-bound active form, whereas Rab3 GAP stimulates the reverse reaction. Of the four members of the Rab3 subfamily, evidence is accumulating that Rab3A is involved in Ca2+-dependent exocytosis, particularly in neurotransmitter release. We first analyzed the subcellular localization of Rab3 GEP and GAP in rat brain. Subcellular fractionation analysis showed that both Rab3 GEP and GAP were enriched in the synaptic soluble fraction. Immunocytochemical analysis in primary cultured rat hippocampal neurons showed that both Rab3 GEP and GAP were concentrated at the presynaptic nerve terminals. We then examined whether Rab3 GEP and GAP were involved in Ca2+-dependent exocytosis by use of human growth hormone (GH) co-expression assay system of cultured PC12 cells. Overexpression of the deletion mutant of Rab3 GEP possessing the catalytic activity reduced the high K+-induced GH release without affecting the basal GH release, whereas that of the deletion mutant lacking the catalytic activity showed no effect on the high K+-induced GH release. In contrast, overexpression of Rab3 GAP or its deletion mutant possessing the catalytic activity did not affect the high K+-induced GH release or the basal GH release. These results indicate that Rab3 GEP and GAP are colocalized with Rab3A at the synaptic release sites and suggest that they regulate the activity of Rab3A and are involved in Ca2+-dependent exocytosis.
Publication
Journal: Cancer Treatment Reviews
August/4/2011
Abstract
BACKGROUND
Neuroendocrine carcinomas of unknown primary (NCUP) represent a specific subset with relatively favorable prognosis. Data on biology, management and outcome of NCUP patients have not been systematically reviewed neither compared to those of neuroendocrine tumors of known primary.
METHODS
We systematically reviewed all publications studying neuroendocrine CUP patients and presented a single center retrospective patient series. In addition, we analyzed and specified the similarities and/or differences between NCUP and other neuroendocrine malignancies.
RESULTS
Five hundred patients with NCUP constituted a heterogeneous cohort in terms of histology, grade, anatomic site and tumor biology in published series and were managed mostly with platinum-based regimens. Among 294 patients with available outcome data, a median survival of 15.5 months (range 11.6-40) was observed. Comparative analysis with neuroendocrine solid tumors (NET) revealed that poorly-differentiated NCUP share an aggressive natural history and a dismal prognosis similar to high grade pulmonary and extrapulmonary neuroendocrine carcinomas (Large Cell Neuroendocrine bronchial Carcinomas, LCNEC and poorly differentiated gastroenteropancreatic tumors, GEP-NET). Well differentiated NCUP reveal a more indolent course with a survival range resembling that of typical and atypical pulmonary carcinoids, well differentiated gastrointestinal NETs and limited small cell lung carcinomas.
CONCLUSIONS
No evidence for distinct biology or outcome of NCUP patients emerged when histological grade was matched for known primary NETs. The high heterogeneity of the NCUP subgroup limits the potential for identification of reliable prognosticators and hinders development of novel targeted therapies.
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