Clinical procedure for colon carcinoma tissue sampling directly affects the cancer marker-capacity of VEGF family members

Background: mRNA levels of members of the Vascular Endothelial Growth Factor family (VEGF-A, -B, -C, -D, Placental Growth Factor/PlGF) have been investigated as tissue-based markers of colon cancer. These studies, which used specimens obtained by surgical resection or colonoscopic biopsy, yielded contradictory results. We studied the effect of the sampling method on the marker accuracy of VEGF family members. Methods: Comparative RT-qPCR analysis was performed on healthy colon and colon carcinoma samples obtained by biopsy (n = 38) or resection (n = 39) to measure mRNA expression levels of individual VEGF family members. mRNA levels of genes encoding the eicosanoid enzymes cyclooxygenase 2 (COX2) and 5-lipoxygenase (5-LOX) and of genes encoding the hypoxia markers glucose transporter 1 (GLUT-1) and carbonic anhydrase IX (CAIX) were included as markers for cellular stress and hypoxia. Results: Expression levels of COX2, 5-LOX, GLUT-1 and CAIX revealed the occurrence in healthy colon resection samples of hypoxic cellular stress and a concurrent increment of basal expression levels of VEGF family members. This increment abolished differential expression of VEGF-B and VEGF-C in matched carcinoma resection samples and created a surgery-induced underexpression of VEGF-D. VEGF-A and PlGF showed strong overexpression in carcinoma samples regardless of the sampling method. Conclusions: Sampling-induced hypoxia in resection samples but not in biopsy samples affects the marker-reliability of VEGF family members. Therefore, biopsy samples provide a more accurate report on VEGF family mRNA levels. Furthermore, this limited expression analysis proposes VEGF-A and PlGF as reliable, sampling procedure insensitive mRNA-markers for molecular diagnosis of colon cancer

Molecular imaging of tumor-associated angiogenesis using a novel magnetic resonance imaging contrast agent targeting αvβ3 integrin

The recent introduction of biological anticancer therapy has renewed the interest in functional imaging of tumor-associated angiogenesis (TAA) as a tool to monitor early therapy response. The present study evaluated imaging of TAA using P1227, a novel, small molecular magnetic resonance imaging (MRI) probe targeting alpha(v)beta(3) integrin. HT29 human colorectal cancers were grown in athymic mice. Dynamic MRI was performed using a three-dimensional VIBE sequence up to 110 min after injection of P1227 or gadolinium-tetraazacyclododecane tetraacetic acid (Gd-DOTA). Specificity was assessed by using P1227 1 h after intravenous administration of the alpha(v)beta(3) inhibitor cilengitide. Regions of interest were drawn encompassing the tumor rim and normal muscle. Imaging data were compared with microvessel density and alpha(v)beta(3) expression. Using P1227, specific enhancement of the angiogenic tumor rim, but not of normal muscle, was observed, whereas Gd-DOTA enhanced tumor and normal muscle. After administering cilengitide, enhancement with P1227, but not with DOTA, was significantly suppressed during the first 20 min. When using P1227, a significant correlation was observed between normalized enhancement of the tumor rim and immunohistochemical alpha(v)beta(3) integrin expression. Molecular MRI using a small monogadolinated tracer targeting alpha(v)beta(3) integrin and moderate magnetic field strength holds promise in assessing colorectal TAA

Noninvasive monitoring of radiotherapy-induced microvascular changes using dynamic contrast enhanced magnetic resonance imaging (DCE-MRI) in a colorectal tumor model

To examine dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) with a macromolecular contrast agent (P792) to visualize effects of radiotherapy (RT) on microvascular leakage in a colorectal cancer model.Journal Articleinfo:eu-repo/semantics/publishe

The Belgian Virtual Tumorbank: A Tool for Translational Cancer Research

Background: Biobanks play a critical role in cancer research by providing high quality biological samples for research. However, the availability of tumor samples in single research institutions is often limited, especially for rare cancers. In order to facilitate the search for samples scattered among different Belgian institutions, a nationwide virtual tumorbank project was launched and is operational since February 2012. The Belgian Virtual Tumorbank (BVT) network encompasses the tumor biobanks from eleven Belgian university hospitals that collect and store residual human tumor samples locally and is coordinated by the Belgian Cancer Registry.Materials and Methods: A web application was developed and consists of two modules. The registration module (BVTr) centralizes the tumor sample data from the local partner biobanks. The catalog module (BVTc) allows researchers to trace the tumor samples in the 11 tumor biobanks. The BVTc contains patient, medical and technical data, but excludes identifying information to ensure privacy of individuals. Automatic and manual controls guarantee high quality data on the samples requested by scientists for research purposes in oncology. A major advantage of the BVT network is that the available data can be linked to the data of the Belgian Cancer Registry for quality control purposes.Results: Currently, more than 92,000 registrations are available in the catalog. Twenty-seven percent of the residual primary tumor samples originate from breast tissue, but also less frequent localisations such as head and neck (4%), male genital organs (1.7%), and urinary tract (1%) are available. In addition to the residual tumor tissue samples, also other available material can be stored and registered by the local biobanks. The most common type is corresponding normal tissue (19%).Other frequently available materials are plasma, blood, serum, DNA, and buffy coat. Even PBMCs, RNA, cytology, and urine are available in some cases.Discussion and Conclusion: The BVT catalog is a valuable source of information for oncology research and the ultimate goal is to promote multidisciplinary cancer research (i.e., pathogenesis, disease prediction, prevention, diagnosis, treatment, and prognosis) for the benefit of all cancer patients

GSyellow, a multifaceted tag for functional protein analysis in monocot and dicot plants

The ability to tag proteins has boosted the emergence of generic molecular methods for protein functional analysis. Fluorescent protein tags are used to visualize protein localization, and affinity tags enable the mapping of molecular interactions by, for example, tandem affinity purification or chromatin immunoprecipitation. To apply these widely used molecular techniques on a single transgenic plant line, we developed a multifunctional tandem affinity purification tag, named GS(yellow), which combines the streptavidin-binding peptide tag with citrine yellow fluorescent protein. We demonstrated the versatility of the GS(yellow) tag in the dicot Arabidopsis (Arabidopsis thaliana) using a set of benchmark proteins. For proof of concept in monocots, we assessed the localization and dynamic interaction profile of the leaf growth regulator ANGUSTIFOLIA3 (AN3), fused to the GS(yellow) tag, along the growth zone of the maize (Zea mays) leaf. To further explore the function of ZmAN3, we mapped its DNA-binding landscape in the growth zone of the maize leaf through chromatin immunoprecipitation sequencing. Comparison with AN3 target genes mapped in the developing maize tassel or in Arabidopsis cell cultures revealed strong conservation of AN3 target genes between different maize tissues and across monocots and dicots, respectively. In conclusion, the GS(yellow) tag offers a powerful molecular tool for distinct types of protein functional analyses in dicots and monocots. As this approach involves transforming a single construct, it is likely to accelerate both basic and translational plant research

The membrane-localized protein kinase MAP4K4/TOT3 regulates thermomorphogenesis

Plants respond to mild warm temperature conditions by increased elongation growth of organs to enhance cooling capacity, in a process called thermomorphogenesis. To this date, the regulation of thermomorphogenesis has been exclusively shown to intersect with light signalling pathway. To identify regulators of thermomorphogenesis that are conserved in flowering plants, we map changes in protein phosphorylation in both dicots and monocots exposed to warm temperature. We identify MITOGEN-ACTIVATED PROTEIN KINASE KINASE KINASE KINASE4 (MAP4K4)/TARGET OF TEMPERATURE3 (TOT3) as a regulator of thermomorphogenesis that impinges on brassinosteroid signalling in Arabidopsis thaliana. In addition, we show that TOT3 plays a role in thermal response in wheat, a monocot crop. Altogether, the conserved thermal regulation by TOT3 expands our knowledge of thermomorphogenesis beyond the well-studied pathways and can contribute to ensuring food security under a changing climate

The Diaphragm and Lubricant Gel for Prevention of Cervical Sexually Transmitted Infections: Results of a Randomized Controlled Trial

BACKGROUND: We evaluated the effectiveness of the Ortho All-Flex Diaphragm, lubricant gel (Replens) and condoms compared to condoms alone on the incidence of chlamydial and gonococcal infections in an open-label randomized controlled trial among women at risk of HIV/STI infections. METHODS: We randomized 5045 sexually-active women at three sites in Southern Africa. Participants who tested positive for curable STIs were treated prior to enrollment as per local guidelines. Women were followed quarterly and tested for Chlamydia trachomatis (CT) or Neisseria gonorrhoeae (GC) infection by nucleic-acid amplification testing (Roche Amplicor) using first-catch urine specimens. STIs detected at follow-up visits were treated. We compared the incidence of first infection after randomization between study arms in both intent-to-treat (ITT) and per-protocol populations. FINDINGS: Baseline demographic, behavioral and clinical characteristics were balanced across study arms. Nearly 80% of participants were under 35 years of age. Median follow-up time was 21 months and the retention rate was over 93%. There were 471 first chlamydia infections, 247 in the intervention arm and 224 in the control arm with an overall incidence of 6.2/100 woman-years (wy) (relative hazard (RH) 1.11, 95% Confidence Interval (CI): 0.93-1.33; p = 0.25) and 192 first gonococcal infections, 95 in the intervention arm and 97 in the control arm with an overall incidence of 2.4/100wy (RH 0.98, 95%CI: 0.74-1.30; p = 0.90). Per protocol results indicated that when diaphragm adherence was defined as "always use" since the last visit, there was a significant reduction in the incidence of GC infection among women randomized to the intervention arm (RH 0.61, 95%CI: 0.41-0.91, P = 0.02). INTERPRETATION: There was no difference by study arm in the rate of acquisition of CT or GC. However, our per-protocol results suggest that consistent use of the diaphragm may reduce acquisition of GC. TRIAL REGISTRATION: ClinicalTrials.gov NCT00121459