Classification of rat mammary carcinoma with large scale in vivo microwave measurements.

Mammary carcinoma, breast cancer, is the most commonly diagnosed cancer type among women. Therefore, potential new technologies for the diagnosis and treatment of the disease are being investigated. One promising technique is microwave applications designed to exploit the inherent dielectric property discrepancy between the malignant and normal tissues. In theory, the anomalies can be characterized by simply measuring the dielectric properties. However, the current measurement technique is error-prone and a single measurement is not accurate enough to detect anomalies with high confidence. This work proposes to classify the rat mammary carcinoma, based on collected large-scale in vivo S[Formula: see text] measurements and corresponding tissue dielectric properties with a circular diffraction antenna. The tissues were classified with high accuracy in a reproducible way by leveraging a learning-based linear classifier. Moreover, the most discriminative S[Formula: see text] measurement was identified, and to our surprise, using the discriminative measurement along with a linear classifier an 86.92% accuracy was achieved. These findings suggest that a narrow band microwave circuitry can support the antenna enabling a low-cost automated microwave diagnostic system.

FOXM1 Inhibitors as Potential Diagnostic Agents: First Generation of a PET Probe Targeting FOXM1 To Detect Triple-Negative Breast Cancer in†vitro and in†vivo.

The FOXM1 protein controls the expression of essential genes related to cancer cell cycle progression, metastasis, and chemoresistance. We hypothesize that FOXM1 inhibitors could represent a novel approach to develop 18 F-based radiotracers for Positron Emission Tomography (PET). Therefore, in this report we describe the first attempt to use 18 F-labeled FOXM1 inhibitors to detect triple-negative breast cancer (TNBC). Briefly, we replaced the original amide group in the parent drug FDI-6 for a ketone group in the novel AF-FDI molecule, to carry out an aromatic nucleophilic (18 F)-fluorination. AF-FDI dissociated the FOXM1-DNA complex, decreased FOXM1 levels, and inhibited cell proliferation in a TNBC cell line (MDA-MB-231). [18 F]AF-FDI was internalized in MDA-MB-231 cells. Cell uptake inhibition experiments showed that AF-FDI and FDI-6 significantly decreased the maximum uptake of [18 F]AF-FDI, suggesting specificity towards FOXM1. [18 F]AF-FDI reached a tumor uptake of SUV=0.31 in MDA-MB-231 tumor-bearing mice and was metabolically stable 60 min post-injection. These results provide preliminary evidence supporting the potential role of FOXM1 to develop PET radiotracers.

A Method to Pre-Screen Rat Mammary Gland Whole-Mounts Prior To RNAscope.

RNAscope is a quantitative in situ gene expression measurement technique that preserves the spatial aspect of intact tissue; thus, allowing for comparison of specific cell populations and morphologies. Reliable and accurate measurement of gene expression in tissue is dependent on preserving RNA integrity and the quantitative nature of RNAscope. The purpose of this study was to determine if the quantitative nature of RNAscope was retained following processing and carmine staining of mammary gland whole-mounts, which are commonly used to identify lesions, such as hyperplasia and ductal carcinoma in situ (DCIS). We were concerned that handling and procedures required to visualize microscopic disease lesions might compromise RNA integrity and the robustness of RNAscope. No effect on the quantitative abilities of RNAscope was detected when mammary gland whole-mounts were pre-screened for lesions of interest prior to RNAscope. This was determined in comparison to tissue that had been formalin-fixed and paraffin embedded (FFPE) immediately after collection. The ability to pre-screen whole-mounts allowed unpalpable diseased lesions to be identified without labor-intensive serial sectioning of tissue samples to find diseased tissue. This method is applicable to evaluate mammary gland whole-mounts during normal mammary gland development, function, and disease progression.

Noninvasive Cancer Diagnosis In Vivo Based on a Viscosity-Activated Near-Infrared Fluorescent Probe.

Effective and noninvasive cancer diagnosis is expected to ease the burden of continued increased deaths worldwide. Herein, we proposed viscosity of the tumor microenvironment as a biomarker and further develop a versatile optical agent, TBM-V, for monitoring tumor microenvironmental viscosity alterations to achieve cancer diagnosis, therapeutic effect tracking, and anticancer drug screening. When in highly viscous media, near-infrared signals of TBM-V are specifically activated, endowing the probe with the capacity of avoiding biological autofluorescence and achieving high signal-to-noise ratio imaging. The results of vascular imaging disclosed higher fluorescence of the blood vessels in the tumor than the normal ones, implying tumors being pointed out with brighter fluorescence. With the assistance of fluorescence imaging technology, TBM-V achieved noninvasively identifying cancer in vivo with high signal-to-noise ratio imaging. In addition, the capability of TBM-V to evaluate anticancer drug efficacy with viscosity as a robust biomarker was explored. Furthermore, as a proof of concept, screening of the anticancer drugs is also realized through in situ monitoring of the microenvironmental viscosity fluctuations of the tumor with TBM-V. Note that this proposed fluorescence imaging method outperforms the clinical hematoxylin and eosin (H&E) staining assay with the advantageous features of noninvasive and in vivo characteristics. We expected that this unique strategy will reinvigorate the continued perfection of the cancer diagnosis systems.

Acute toxicity analysis of Disarib, an inhibitor of BCL2.

Small molecule inhibitors targeting BCL2 are explored as anticancer therapeutics. Previously, we have reported identification and characterization of a novel BCL2 inhibitor, Disarib. Disarib induced cancer cell death in a BCL2 dependent manner in different cancer cell lines and mouse tumor models when it was administered intraperitoneally. In the present study, using two syngeneic mouse models, breast adenocarcinoma (EAC) and Dalton's lymphoma (DLA), we show that oral administration of Disarib resulted in significant tumor regression in a concentration dependent manner. Importantly, tumor developed in both female and male mice were equally sensitive to Disarib. Further, we have investigated the toxicity of Disarib in normal cells. Single dose toxicity analysis of Disarib in male and female mice after oral administration revealed no significant variations compared to control group for parameters such as body weight, food and water consumption and behavioural changes which were analysed for the entire period of study. Haematological and histopathological analyses also did not show any significant difference from the control groups. Thus, our results reveal safe use of Disarib as a small molecule inhibitor and provide the foundation for investigation of other preclinical studies.

Cytokines of the Lymph and Blood Serum as Markers of Oncogenesis and Efficiency of Therapy in Chemically Induced Breast Cancer in Wistar Rats.

We studied the levels of serum and lymph cytokines involved in the pathogenesis of BC. BC was induced by injection of N-methyl-N-nitrosourea to Wistar rats. The animals underwent surgery, or received polychemotherapy (cyclophosphamide, methotrexate, and 5-fluorouracil), or surgical treatment was combined with polychemotherapy; in a special group, Panagen (fragmented DNA) was added to polychemotherapy. Cytokine concentration in the lymph was measured using Bio-Plex Pro Rat Cytokoness 24-Plex Assay test system (Bio-Rad). In rats with BC, the content of most studied cytokines (IL-1ß, IL-2, IL-4, IL-6, IL-7, IL-12, IL-13, MIP-1α, MIP-3α, RANTES, TNFα, and MCP-1) in the lymph and blood was significantly higher, while the content of IL-10 and GRO/KC was lower than in intact animals. Surgical resection of the tumor led to a significant decrease in the content of both pro- and anti-inflammatory cytokines in the lymph. Polychemotherapy led to a significant decrease in the content of IL-1ß, IL-4, IL-6, IL-7, MIP-1α, MIP-3α, and RANTES in the serum and lymph. Comparison of the cytokine content in the serum and lymph of operated animals after polychemotherapy with and without Panagen showed that the content of most cytokines (IL-5, IL-6, IL-7, IL-10, IL-13, IL-17A , IL-18, GRO/KC, IFNγ, and MIP-3α) was higher after Panagen administration.

Probing and Enhancing Ligand-Mediated Active Targeting of Tumors Using Sub-5 nm Ultrafine Iron Oxide Nanoparticles.

Rationale: "Active targeting" based on the ligand-target affinity is a common strategy to precisely deliver nanoparticle (NP) imaging probes or drug carriers to the diseased tissue. However, such ligand-mediated active targeting inevitably takes place with prerequisite "passive targeting", driven by the enhanced permeability and retention (EPR) effect. Thus, the efficiency of active targeting in relation to off-targeted unbound NPs is of great importance in quantitative imaging of tumor biomarkers and delivery. With the notion that easy clearance of off-targeted uIONPs may lead to enhanced active targeting and tumor accumulation, we examined the NP size effect on "active targeting" of the transferrin receptor (TfR) using transferrin (Tf)-conjugated sub-5 nm (3 nm core) ultrafine iron oxide NPs (uIONPs) and larger IONPs (30 nm core). Methods: Green fluorescent dye (FITC)-labeled active targeting uIONPs (FITC-Tf-uIONPs) and red fluorescent dye (TRITC)-labeled passive targeting uIONPs (TRITC-uIONPs) were prepared. FITC-Tf-IONPs and TRITC-IONPs were used as comparison for the NP size effect. Multiphoton imaging, confocal fluorescence imaging, histological staining and computational analysis were applied to track different types of NPs in tumors at 1, 3 and 24 hours after co-injection of equal amounts of paired NPs, e.g., active targeting FITC-Tf-uIONPs and non-targeting TRITC-uIONPs, or FITC-Tf-IONPs and TRITC-IONPs into the same mice bearing 4T1 mouse mammary tumors. Results: Active targeting uIONPs exhibited an almost 6-fold higher level of tumor retention with deeper penetration comparing to non-targeting uIONPs at 24 hours after co-injection. However, accumulation of active targeting IONPs with a 30-nm core is only about 1.15-fold higher than non-targeting IONPs. The enhanced active targeting by uIONPs can be attributed to the size dependent clearance of unbound off-targeted NPs, as majority off-targeted uIONPs were readily cleared from the tumor by intravasation back into tumor blood vessels likely due to high interstitial pressure, even though they are not favorable for macrophage uptake. Conclusion: Ligand-mediated active targeting improves the delivery and accumulation of the sub-5 nm NPs. The improvement on active targeting is size-dependent and facilitated by NPs with sub-5 nm core sizes. Thus, sub-5 nm NPs may serve as favorable platforms for development of NP-based molecular imaging probes and targeted drug carriers.

Topical dual-probe staining using quantum dot-labeled antibodies for identifying tumor biomarkers in fresh specimens.

PURPOSE: Rapid, intra-operative identification of tumor tissue in the margins of excised specimens has become an important focus in the pursuit of reducing re-excision rates, especially for breast conserving surgery. Dual-probe difference specimen imaging (DDSI) is an emerging approach that uses the difference in uptake/clearance kinetics between a pair of fluorescently-labeled stains, one targeted to a biomarker-of-interest and the other an untargeted isotype, to reveal receptor-specific images of the specimen. Previous studies using antibodies labeled with either enhanced Raman particles or organic fluorophores have shown promising tumor vs. normal diagnostic performance. Yet, the unique properties of quantum dot-labeled antibody complexes (QDACs), which provide spectrally-distinct fluorescence emission from a common excitation source, make them ideal candidates for this application. Herein, we evaluate the diagnostic performance of QDAC-based DDSI in excised xenografts. PROCEDURES: Excised fresh specimens of normal tissue and human tumor xenografts with elevated expression of HER2 were stained with a HER2-targeted QDAC and an untargeted QDAC isotype. Stained specimens were imaged on a custom hyperspectral imaging system capable of spectrally separating the quantum dot signatures, and images processed using the DDSI approach. The diagnostic performance of this technique under different incubation temperatures and probe concentrations was evaluated using receiver-operator characteristic analysis. RESULTS: HER2-targeted QDAC-DDSI was able to distinguish HER2(+) tumors from normal tissue with reasonably high diagnostic performance; however, this performance was sensitive to temperature during the staining procedure. Area under the curve values were 0.61 when staining at room temperature but increased to over 0.81 when staining at 37 °C. Diagnostic performance was not affected by increasing stain concentration. CONCLUSIONS: This study is the first to report dual-probe difference imaging of specimens using QDACs and hyperspectral imaging. Our results show promising diagnostic performance under certain conditions, and compel further optimization and evaluation of this intra-operative margin assessment technique.

Metabolomic studies of breast cancer in murine models: A review.

BACKGROUND: Metabolomic strategies have been extensively used to search for biomarkers of disease, including cancer, in biological complex mixtures such as cells, tissues and biofluids. In breast cancer research, murine models are of great value and metabolomics has been increasingly applied to characterize tumor or organ tissues, or biofluids, for instance to follow-up metabolism during cancer progression or response to specific therapies. SCOPE OF REVIEW: This review briefly introduces the different murine models used in breast cancer research and proceeds to present the metabolomic studies reported so far to describe the deviant metabolic behavior associated to breast cancer, in each type of model: xenografts (cell- or patient-derived), spontaneous (naturally-occurring or genetically engineered) and carcinogen-induced. The type of sample and strategies followed are identified, as well as the main findings from of study. MAJOR CONCLUSIONS: Metabolomics has gradually become relevant in characterizing murine models of breast cancer, using either Nuclear Magnetic Resonance (NMR) or Mass Spectromety (MS). Both tissue and biofluids are matrixes of interest in this context, although in some type of models, reports have focused primarily on the former. The aims of tissue studies have comprised the search for mechanistic knowledge of carcinogenesis, metastasis development and response/resistance to therapies. Biofluid metabolomics has mainly aimed at finding non-invasive biomarkers for early breast cancer detection or prognosis determination. GENERAL SIGNIFICANCE: Metabolomics provides exquisite detail on murine tumor and systemic metabolism of breast cancer. This knowledge paves the way for the discovery of new biomarkers, potentially translatable to in vivo non-invasive patient follow-up.

TLR5 is a new reporter for triple-negative breast cancer indicated by radioimmunoimaging and fluorescent staining.

Triple-negative breast cancer (TNBC) is a highly aggressive tumour that lacks marker for targeted diagnosis. Recently, it was reported that toll-like receptor 5 (TLR5) was associated with some kind of tumours, especially in TNBC, but whether it could be used as a non-invasive monitoring target is not fully understood. Here, we established TLR5- 4T1 cell line with lentivirus-shRNA-TLR5 knock-down transfection (with tag GFP, green fluorescent protein, TLR5- 4T1) and control TLR5+ 4T1 cell line with negative control lentivirus transfection. The effect of TLR5 down-regulation was detected with qPCR and Western blot. 125 I-anti-TLR5 mAb and control isotype 125 I-IgG were prepared and injected to TLR5+/- 4T1-bearing mice models, respectively. Whole-body phosphor-autoradiography, fluorescence imaging and biodistribution were performed. Furthermore, ex vivo tumour TLR5 expression was proved through immunohistochemistry staining. We found that 125 I-anti-TLR5 mAb could bind to TLR5+ 4T1 with high affinity and specificity. Whole-body phosphor-autoradiography after 125 I-anti-TLR5 mAb injection showed TLR5+ 4T1 tumour images in 24 hours, more clearly in 48 hours. Radioactivities in tumour tissues were positively related with TLR5 expression. Biodistribution assay showed that 125 I-anti-TLR5 mAb was mainly metabolized through the liver and kidney, and 125 I-anti-TLR5 mAb was much more accumulated in TLR5+ 4T1 tumour than TLR5- 4T1. In vivo fluorescence imaging successfully showed tumour tissues clearly both in TLR5+ and TLR5- 4T1 mice compared with lentivirus untreated 4T1 tumour. Immunohistochemistry staining showed that TLR5 expression in tumours was indeed down-regulated in TLR5- 4T1 mice. Our results indicated that 125 I-antiTLR5 mAb was an ideal agent for non-invasive imaging of TLR5+ tumours; TLR5 may be as a novel molecular target for TNBC non-invasive diagnosis.

YAP1 overexpression is associated with poor prognosis of breast cancer patients and induces breast cancer cell growth by inhibiting PTEN.

YES-associated protein 1 (YAP1) plays a key role as a transcriptional coactivator in the Hippo tumor suppressor pathway. YAP1 is overexpressed in a variety of cancers and is considered to be encoded by a proto-oncogene. However, the role of YAP1 remains debatable, because both gain and loss of YAP1 expression have both been reported in breast cancer (BC). Here, we found that elevated expression of YAP1 mRNA in BC was negatively correlated with relapse-free, distant metastases-free and overall survival rates. We then knocked down or overexpressed YAP1 in human BC cells, and examined cell proliferation, apoptosis, and tumorigenic ability in vivo. We identified that YAP1 promotes cell growth and inhibits cell apoptosis of BC through the phosphatase and tensin homolog deleted on chromosome 10-AKT signaling pathway, and thus suggest that YAP1 might serve as a new target for inhibiting BC progression.

Characterization of triple-negative breast cancer preclinical models provides functional evidence of metastatic progression.

Triple-negative breast cancer (TNBC), an aggressive, metastatic and recurrent breast cancer (BC) subtype, currently suffers from a lack of adequately described spontaneously metastatic preclinical models that faithfully reproduce the clinical scenario. We describe two preclinical spontaneously metastatic TNBC orthotopic murine models for the development of advanced therapeutics: an immunodeficient human MDA-MB-231-Luc model and an immunocompetent mouse 4T1 model. Furthermore, we provide a broad range of multifactorial analysis for both models that could provide relevant information for the development of new therapies and diagnostic tools. Our comparisons uncovered differential growth rates, stromal arrangements and metabolic profiles in primary tumors, and the presence of cancer-associated adipocyte infiltration in the MDA-MB-231-Luc model. Histopathological studies highlighted the more rapid metastatic spread to the lungs in the 4T1 model following a lymphatic route, while we observed both homogeneous (MDA-MB-231-Luc) and heterogeneous (4T1) metastatic spread to axillary lymph nodes. We encountered unique metabolomic signatures in each model, including crucial amino acids and cell membrane components. Hematological analysis demonstrated severe leukemoid and lymphoid reactions in the 4T1 model with the partial reestablishment of immune responses in the immunocompromised MDA-MB-231-Luc model. Additionally, we discovered ß-immunoglobulinemia and increased basal levels of G-CSF correlating with a metastatic switch, with G-CSF also promoting extramedullary hematopoiesis (both models) and causing hepatosplenomegaly (4T1 model). Overall, we believe that the characterization of these preclinical models will foster the development of advanced therapeutic strategies for TNBC treatment, especially for the treatment of patients presenting both, primary tumors and metastatic spread.

Upregulation of circ-UBAP2 predicts poor prognosis and promotes triple-negative breast cancer progression through the miR-661/MTA1 pathway.

Recently, a large number of studies have shown that circular RNA (circRNA) is involved in the development and progression of human cancer. However, its role in triple-negative breast cancer (TNBC) remains largely unknown. In this study, a novel circRNA, circ-UBAP2 (hsa_circ_0001846), was shown to be markedly upregulated in TNBC. Moreover, high circ-UBAP2 expression was closely associated with larger tumour size (p = 0.003), advanced TNM stage (p = 0.005), lymph node metastasis (p = 0.002), and unfavourable prognosis (p = 0.0256). Functionally, lentivirus-mediated stable knockdown of circ-UBAP2 dramatically weakened the ability of TNBC cells to proliferate and migrate and induced apoptosis in vitro and in vivo. Regarding the mechanism, we found that circ-UBAP2 was mainly observed in the cytoplasm and was capable of sponging miRNA-661 to increase the expression of the oncogene MTA1. Additionally, silencing of miRNA-661 or overexpression of MTA1 could partially rescue the attenuated malignant phenotype caused by circ-UBAP2 knockdown. Taken together, our data reveal that circ-UBAP2 plays a vital regulatory role in TNBC via the miR-661/MTA1 axis and may serve as a promising therapeutic target for TNBC patients.

Correlation between stress drop and applied strain as a biomarker for tumor detection.

This is the first study to measure the viscoelastic behavior of tumor tissues using stepwise compression-relaxation testing, and investigate the measured (Δσ-ε) relation between stress drop (Δσ) and applied strain (ε) as a biomarker for tumor detection. Stepwise compression-relaxation testing was implemented via a 2D tactile sensor to measure stress drop at each applied strain of a sample. Pearson correlation analysis was conducted to quantify the measured Δσ-ε relation as slope of stress drop versus applied strain (m=Δσ/ε) and coefficient of determination (R2). The measured results on soft materials revealed no dependency of coefficient of determination on the testing parameters and dependency of slope on them. Three groups of tissues: five mouse breast tumor (BT) tissues ex vivo, two mouse pancreatic tumor (PT) tissues in vivo and six normal tissues, were measured by using different testing parameters. Coefficient of determination was found to show significant difference among the center, edge and outside sites of all the BT tissues, and no difference between the BT outside sites and the normal tissues. Coefficient of determination also revealed significant difference between before and after treatment of the PT tissues, and no difference between the PT tissues after treatment and the normal tissues. Moreover, coefficient of determination of the PT tissues before treatment was found to be significantly different from that of the BT center sites, but slope failed to capture their difference. Dummy tumors made of silicon rubbers were found to behave differently from the native tumors. By removing the need of fitting the time-dependent data with a viscoelastic model, this study offered a time-efficient solution to quantifying the viscosity for tumor detection.

Optoacoustics delineates murine breast cancer models displaying angiogenesis and vascular mimicry.

BACKGROUND: Optoacoustic tomography (OT) of breast tumour oxygenation is a promising new technique, currently in clinical trials, which may help to determine disease stage and therapeutic response. However, the ability of OT to distinguish breast tumours displaying different vascular characteristics has yet to be established. The aim of the study is to prove OT as a sensitive technique for differentiating breast tumour models with manifestly different vasculatures. METHODS: Multispectral OT (MSOT) was performed in oestrogen-dependent (MCF-7) and oestrogen-independent (MDA-MB-231) orthotopic breast cancer xenografts. Total haemoglobin (THb) and oxygen saturation (SO2MSOT) were calculated. Pathological and biochemical evaluation of the tumour vascular phenotype was performed for validation. RESULTS: MCF-7 tumours show SO2MSOT similar to healthy tissue in both rim and core, despite significantly lower THb in the core. MDA-MB-231 tumours show markedly lower SO2MSOT with a significant rim-core disparity. Ex vivo analysis revealed that MCF-7 tumours contain fewer blood vessels (CD31+) that are more mature (CD31+/aSMA+) than MDA-MB-231. MCF-7 presented higher levels of stromal VEGF and iNOS, with increased NO serum levels. The vasculogenic process observed in MCF-7 was consistent with angiogenesis, while MDA-MB-231 appeared to rely more on vascular mimicry. CONCLUSIONS: OT is sensitive to differences in the vascular phenotypes of our breast cancer models.

Network Representation of T-Cell Repertoire- A Novel Tool to Analyze Immune Response to Cancer Formation.

The T cell repertoire potentially presents complexity compatible, or greater than, that of the human brain. T cell based immune response is involved with practically every part of human physiology, and high-throughput biology needed to follow the T-cell repertoire has made great leaps with the advent of massive parallel sequencing [1]. Nevertheless, tools to handle and observe the dynamics of this complexity have only recently started to emerge [e.g., 2, 3, 4] in parallel with sequencing technologies. Here, we present a network-based view of the dynamics of the T cell repertoire, during the course of mammary tumors development in a mouse model. The transition from the T cell receptor as a feature, to network-based clustering, followed by network-based temporal analyses, provides novel insights to the workings of the system and provides novel tools to observe cancer progression via the perspective of the immune system. The crux of the approach here is at the network-motivated clustering. The purpose of the clustering step is not merely data reduction and exposing structures, but rather to detect hubs, or attractors, within the T cell receptor repertoire that might shed light on the behavior of the immune system as a dynamic network. The Clone-Attractor is in fact an extension of the clone concept, i.e., instead of looking at particular clones we observe the extended clonal network by assigning clusters to graph nodes and edges to adjacent clusters (editing distance metric). Viewing the system as dynamical brings to the fore the notion of an attractors landscape, hence the possibility to chart this space and map the sample state at a given time to a vector in this large space. Based on this representation we applied two different methods to demonstrate its effectiveness in identifying changes in the repertoire that correlate with changes in the phenotype: (1) network analysis of the TCR repertoire in which two measures were calculated and demonstrated the ability to differentiate control from transgenic samples, and, (2) machine learning classifier capable of both stratifying control and trangenic samples, as well as to stratify pre-cancer and cancer samples.

Synthesis and evaluation of radioiodinated 1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}piperidin-4-amine derivatives for platelet-derived growth factor receptor ß (PDGFRß) imaging.

Platelet-derived growth factor receptor ß (PDGFRß) is a transmembrane tyrosine kinase receptor and it is upregulated in various malignant tumors. Radiolabeled PDGFRß inhibitors can be a convenient tool for the imaging of tumors overexpressing PDGFRß. In this study, [125I]-1-{5-iodo-2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinoline-8-yl}piperidin-4-amine ([125I]IIQP) and [125I]-N-3-iodobenzoyl-1-{2-[5-(2-methoxyethoxy)-1H-benzo[d]imidazol-1-yl]quinolin-8-yl}-piperidin-4-amine ([125I]IB-IQP) were designed and synthesized, and their potential as PDGFRß imaging agents was evaluated. In cellular uptake experiments, [125I]IIQP and [125I]IB-IQP showed higher uptake by PDGFRß-positive cells than by PDGFRß-negative cells, and the uptake in PDGFRß-positive cells was inhibited by co-culture with PDGFRß ligands. The biodistribution of both radiotracers in normal mice exhibited hepatobiliary excretion as the main route. In mice inoculated with BxPC3-luc (PDGFRß-positive), the tumor uptake of radioactivity at 1h after the injection of [125I]IIQP was significantly higher than that after the injection of [125I]IB-IQP. These results indicated that [125I]IIQP can be a suitable PDGFRß imaging agent. However, further modification of its structure will be required to obtain a more appropriate PDGFRß-targeted imaging agent with a higher signal/noise ratio.

Genome-wide screen for differentially methylated long noncoding RNAs identifies Esrp2 and lncRNA Esrp2-as regulated by enhancer DNA methylation with prognostic relevance for human breast cancer.

The majority of long noncoding RNAs (lncRNAs) is still poorly characterized with respect to function, interactions with protein-coding genes, and mechanisms that regulate their expression. As for protein-coding RNAs, epigenetic deregulation of lncRNA expression by alterations in DNA methylation might contribute to carcinogenesis. To provide genome-wide information on lncRNAs aberrantly methylated in breast cancer we profiled tumors of the C3(1) SV40TAg mouse model by MCIp-seq (Methylated CpG Immunoprecipitation followed by sequencing). This approach detected 69 lncRNAs differentially methylated between tumor tissue and normal mammary glands, with 26 located in antisense orientation of a protein-coding gene. One of the hypomethylated lncRNAs, 1810019D21Rik (now called Esrp2-antisense (as)) was identified in proximity to the epithelial splicing regulatory protein 2 (Esrp2) that is significantly elevated in C3(1) tumors. ESRPs were shown previously to have a dual role in carcinogenesis. Both gain and loss have been associated with poor prognosis in human cancers, but the mechanisms regulating expression are not known. In-depth analyses indicate that coordinate overexpression of Esrp2 and Esrp2-as inversely correlates with DNA methylation. Luciferase reporter gene assays support co-expression of Esrp2 and the major short Esrp2-as variant from a bidirectional promoter, and transcriptional regulation by methylation of a proximal enhancer. Ultimately, this enhancer-based regulatory mechanism provides a novel explanation for tissue-specific expression differences and upregulation of Esrp2 during carcinogenesis. Knockdown of Esrp2-as reduced Esrp2 protein levels without affecting mRNA expression and resulted in an altered transcriptional profile associated with extracellular matrix (ECM), cell motility and reduced proliferation, whereas overexpression enhanced proliferation. Our findings not only hold true for the murine tumor model, but led to the identification of an unannotated human homolog of Esrp2-as which is significantly upregulated in human breast cancer and associated with poor prognosis.

Distinct ON/OFF fluorescence signals from dual-responsive activatable nanoprobes allows detection of inflammation with improved contrast.

Visualization of biochemical changes associated with disease is of great clinical significance, as it should allow earlier, more accurate diagnosis than structural imaging, facilitating timely clinical intervention. Herein, we report combining stimuli-responsive polymers and near-infrared fluorescent dyes (emission max: 790 nm) to create robust activatable fluorescent nanoprobes capable of simultaneously detecting acidosis and oxidative stress associated with inflammatory microenvironments. The spectrally-resolved mechanism of fluorescence activation allows removal of unwanted background signal (up to 20-fold reduction) and isolation of a pure activated signal, which enables sensitive and unambiguous localization of inflamed areas; target-to-background ratios reach 22 as early as 3 h post-injection. This new detection platform could have significant clinical impact in early detection of pathologies, individual tailoring of drug therapy, and image-guided tumor resection.