carbocyanines and Glioma

Precisely locating tumors always proves to be difficult. To find a molecule that can specifically bind to tumor cells is the key. Recently, chlorotoxin (CTX) has been proved to be able to bind to many kinds of tumor cells. The CTX receptor on the cell surface has been demonstrated to be matrix metalloproteinase-2 (MMP-2). Many researchers have combined CTX with other molecules, including 131I, Cy5.5, iron oxide nanoparticles coated by polyethylene glycol (NP-PEG), and so on, and thus synthesized various types of probes that can be detected by gamma-camera, single photon emission computed tomography (SPECT) or magnetic resonance imaging (MRI). With these methods, the binding degree of CTX could be assessed. These studies demonstrated that CTX has a highly specific binding ability, high stability, and security. CTX could also inhibit or kill the tumor cells. A nonviral nanovector has been developed for gene therapy. As a result, it gradually develops into a new method of diagnosis and targeted therapy of tumors. This article reviews the current progress on CTX including the origin, chemical construction, the mechanism of binding with tumor cells, and the application to tumor imaging diagnosis and therapy.

Topics: Brain Neoplasms; Carbocyanines; Chloride Channels; Diagnostic Imaging; Ferric Compounds; Genetic Therapy; Glioma; Humans; Iodine Radioisotopes; Magnetic Resonance Imaging; Matrix Metalloproteinase 2; Nanoparticles; Neoplasm Invasiveness; Neoplasm Metastasis; Polyethylene Glycols; Scorpion Venoms; Tomography, Emission-Computed, Single-Photon

Because of the blood-brain barrier and the high infiltration of glioma cells, the diagnostic accuracy and treatment efficiency of gliomas are still facing challenges. There is an urgent need to explore the integration of diagnostic and therapeutic methods to achieve an accurate diagnosis, guide surgery, and inhibit postoperative recurrence. In this work, we developed a macrophage loaded with a photothermal nanoprobe (MFe

Topics: Animals; Biomimetic Materials; Blood-Brain Barrier; Brain Neoplasms; Carbocyanines; Glioma; Humans; Macrophages; Magnetite Nanoparticles; Male; Materials Testing; Multimodal Imaging; Neoplasms, Experimental; Particle Size; Photothermal Therapy; Porosity; Rats; Rats, Sprague-Dawley; Tumor Cells, Cultured

The efficacy of therapeutics for brain tumors is seriously hampered by multiple barriers to drug delivery, including severe destabilizing effects in the blood circulation, the blood-brain barrier/blood-brain tumor barrier (BBB/BBTB), and limited tumor uptake. Here, a sequential targeting in crosslinking (STICK) nanodelivery strategy is presented to circumvent these important physiological barriers to improve drug delivery to brain tumors. STICK nanoparticles (STICK-NPs) can sequentially target BBB/BBTB and brain tumor cells with surface maltobionic acid (MA) and 4-carboxyphenylboronic acid (CBA), respectively, and simultaneously enhance nanoparticle stability with pH-responsive crosslinkages formed by MA and CBA in situ. STICK-NPs exhibit prolonged circulation time (17-fold higher area under curve) than the free agent, allowing increased opportunities to transpass the BBB/BBTB via glucose-transporter-mediated transcytosis by MA. The tumor acidic environment then triggers the transformation of the STICK-NPs into smaller nanoparticles and reveals a secondary CBA targeting moiety for deep tumor penetration and enhanced uptake in tumor cells. STICK-NPs significantly inhibit tumor growth and prolong the survival time with limited toxicity in mice with aggressive and chemoresistant diffuse intrinsic pontine glioma. This formulation tackles multiple physiological barriers on-demand with a simple and smart STICK design. Therefore, these features allow STICK-NPs to unleash the potential of brain tumor therapeutics to improve their treatment efficacy.

Topics: Animals; Antineoplastic Agents; Blood-Brain Barrier; Boronic Acids; Brain; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Disaccharides; Drug Carriers; Gadolinium DTPA; Glioma; Humans; Hydrogen-Ion Concentration; Kaplan-Meier Estimate; Mice; Mice, Inbred BALB C; Nanoparticles; Transcytosis; Xenograft Model Antitumor Assays

Optical molecular imaging technology that indiscriminately detects intracranial glioblastoma (GBM) can help neurosurgeons effectively remove tumor masses. Transferrin receptor 1 (TfR 1) is a diagnostic and therapeutic target in GBM. A TfR 1-targeted peptide, CRTIGPSVC (CRT), was shown to cross the blood brain barrier (BBB) and accumulate at high levels in GBM tissues. In this study, we synthesized a TfR 1-targeted near-infrared fluorescent (NIRF) probe, Cy5-CRT, for identifying the GBM tissue margin in mouse models.. We initially confirmed the overexpression of TfR 1 in GBM and the tumor-specific homing ability of Cy5-CRT in subcutaneous and orthotopic GBM mouse models. We then examined the feasibility of Cy5-CRT for identifying the tumor margin in orthotopic GBM xenografts. Finally, we compared Cy5-CRT with the clinically used fluorescein sodium in identifying tumor margins.. Cy5-CRT specifically accumulated in GBM tissues and detected the tumor burden with exceptional contrast in mice with orthotopic GBM, enabling fluorescence-guided GBM resection under NIRF live imaging conditions. Importantly, Cy5-CRT recognized the GBM tissue margin more clearly than fluorescein sodium.. The TfR 1-targeted optical probe Cy5-CRT specifically differentiates tumor tissues from the surrounding normal brain with high sensitivity, indicating its potential application for the precise surgical removal of GBM.

Topics: Animals; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Disease Models, Animal; Fluorescein; Fluorescent Dyes; Glioma; Mice; Microscopy, Fluorescence; Optical Imaging; Receptors, Transferrin; Xenograft Model Antitumor Assays

Cavitation-facilitated microbubble-mediated focused ultrasound therapy is a promising method of drug delivery across the blood-brain barrier (BBB) for treating many neurological disorders. Unlike ultrasound thermal therapies, during which magnetic resonance thermometry can serve as a reliable treatment control modality, real-time control of modulated BBB disruption with undetectable vascular damage remains a challenge. Here a closed-loop cavitation controlling paradigm that sustains stable cavitation while suppressing inertial cavitation behavior was designed and validated using a dual-transducer system operating at the clinically relevant ultrasound frequency of 274.3 kHz. Tests in the normal brain and in the F98 glioma model in vivo demonstrated that this controller enables reliable and damage-free delivery of a predetermined amount of the chemotherapeutic drug (liposomal doxorubicin) into the brain. The maximum concentration level of delivered doxorubicin exceeded levels previously shown (using uncontrolled sonication) to induce tumor regression and improve survival in rat glioma. These results confirmed the ability of the controller to modulate the drug delivery dosage within a therapeutically effective range, while improving safety control. It can be readily implemented clinically and potentially applied to other cavitation-enhanced ultrasound therapies.

Topics: Acoustics; Animals; Antibiotics, Antineoplastic; Blood-Brain Barrier; Brain Neoplasms; Carbocyanines; Corpus Striatum; Disease Models, Animal; Doxorubicin; Drug Delivery Systems; Fluorescent Dyes; Glioma; Hippocampus; Luminescent Proteins; Magnetic Resonance Imaging; Male; Microbubbles; Molecular Targeted Therapy; Polyethylene Glycols; Rats; Rats, Sprague-Dawley; Transducers; Ultrasonic Therapy; Ultrasonic Waves

Systemically administered chemotherapeutic drugs are often ineffective in the treatment of invasive brain tumors due to poor therapeutic index. Within gliomas, despite the presence of heterogeneously leaky microvessels, dense extracellular matrix and high interstitial pressure generate a "blood-tumor barrier" (BTB), which inhibits drug delivery and distribution. Meanwhile, beyond the contrast MRI-enhancing edge of the tumor, invasive cancer cells are protected by the intact blood-brain barrier (BBB). Here, we tested whether brain-penetrating nanoparticles (BPN) that possess dense surface coatings of polyethylene glycol (PEG) and are loaded with cisplatin (CDDP) could be delivered across both the blood-tumor and blood-brain barriers with MR image-guided focused ultrasound (MRgFUS), and whether this treatment could control glioma growth and invasiveness. To this end, we first established that MRgFUS is capable of significantly enhancing the delivery of ~60nm fluorescent tracer BPN across the blood-tumor barrier in both the 9L (6-fold improvement) gliosarcoma and invasive F98 (28-fold improvement) glioma models. Importantly, BPN delivery across the intact BBB, just beyond the tumor edge, was also markedly increased in both tumor models. We then showed that a CDDP loaded BPN formulation (CDDP-BPN), composed of a blend of polyaspartic acid (PAA) and heavily PEGylated polyaspartic acid (PAA-PEG), was highly stable, provided extended drug release, and was effective against F98 cells in vitro. These CDDP-BPN were delivered from the systemic circulation into orthotopic F98 gliomas using MRgFUS, where they elicited a significant reduction in tumor invasiveness and growth, as well as improved animal survival. We conclude that this therapy may offer a powerful new approach for the treatment invasive gliomas, particularly for preventing and controlling recurrence.

Topics: Animals; Antineoplastic Agents; Brain; Brain Neoplasms; Cadaverine; Carbocyanines; Cell Line, Tumor; Cell Survival; Cisplatin; Drug Delivery Systems; Drug Liberation; Female; Fluorescent Dyes; Glioma; Magnetic Resonance Imaging; Microbubbles; Peptides; Polyethylene Glycols; Rats, Sprague-Dawley; Tumor Burden; Ultrasonic Waves

Surgical resection is the primary mode for glioma treatment, while gross total resection is difficult to achieve, due to the invasiveness of the gliomas. Meanwhile, the tumor-resection region is closely related to survival rate and life quality. Therefore, we developed optical/magnetic resonance imaging (MRI) bifunctional targeted micelles for glioma so as to delineate the glioma location before and during operation. The micelles were constructed through encapsulation of hydrophobic superparamagnetic iron oxide nanoparticles (SPIONs) with polyethylene glycol-block-polycaprolactone (PEG-b-PCL) by using a solvent-evaporation method, and modified with a near-infrared fluorescent probe, Cy5.5, in addition to the glioma-targeting ligand lactoferrin (Lf). Being encapsulated by PEG-b-PCL, the hydrophobic SPIONs dispersed well in phosphate-buffered saline over 4 weeks, and the relaxivity (r 2) of micelles was 215.4 mM(-1)·s(-1), with sustained satisfactory fluorescent imaging ability, which might have been due to the interval formed by PEG-b-PCL for avoiding the fluorescence quenching caused by SPIONs. The in vivo results indicated that the nanoparticles with Lf accumulated efficiently in glioma cells and prolonged the duration of hypointensity at the tumor site over 48 hours in the MR image compared to the nontarget group. Corresponding with the MRI results, the margin of the glioma was clearly demarcated in the fluorescence image, wherein the average fluorescence intensity of the tumor was about fourfold higher than that of normal brain tissue. Furthermore, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay results showed that the micelles were biocompatible at Fe concentrations of 0-100 μg/mL. In general, these optical/MRI bifunctional micelles can specifically target the glioma and provide guidance for surgical resection of the glioma before and during operation.

Topics: Animals; Carbocyanines; Cell Line, Tumor; Glioma; Lactones; Magnetic Resonance Imaging; Magnetite Nanoparticles; Micelles; Optical Imaging; Polyethylene Glycols; Rats

To improve glioma targeting delivery efficiency and to monitor drug delivery and treatment outcome, a novel tumor microenvironment sensitive size-shrinkable theranostic system was constructed and evaluated. The G-AuNPs-DC-RRGD system was constructed by fabricating small sized gold nanoparticles (AuNPs) onto matrix metalloproteinase-2 (MMP-2) degradable gelatin nanoparticles (GNPs), doxorubicin (DOX) and Cy5.5 were decorated onto AuNPs through a hydrazone bond to enable the system with pH triggered cargoes release, and RRGD, a tandem peptide of RGD and octarginine was surface-modified onto the system to enable it with glioma active targeting ability. In vitro, the size of G-AuNPs-DC-RRGD could effectively shrink from 188.2 nm to 55.9 nm after incubation with MMP-2, while DOX and Cy5.5 were released in a pH dependent manner. Cellular uptake demonstrated that G-AuNPs-DC-RRGD could be effectively taken up by cells with higher intensity than G-AuNPs-DC-PEG. A study of tumor spheroids further demonstrated that the particles with smaller size showed better penetration ability, while RRGD modification could further improve permeability. In vivo, G-AuNPs-DC-RRGD displayed the best glioma targeting and accumulation efficiency, with good colocalization with neovessels. Cy5.5 also was colocalized well with DOX, indicating that Cy5.5 could be used for imaging of DOX delivery.

Topics: Animals; Brain; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Doxorubicin; Drug Carriers; Gelatin; Glioma; Gold; Humans; Hydrogen-Ion Concentration; Matrix Metalloproteinase 2; Metal Nanoparticles; Mice; Mice, Nude; Particle Size; Tissue Distribution; Transplantation, Heterologous; Tumor Microenvironment

The fusion of molecular and anatomical modalities facilitates more reliable and accurate detection of tumors. Herein, we prepared the PEG-Cy5.5 conjugated MnO nanoparticles (MnO-PEG-Cy5.5 NPs) with magnetic resonance (MR) and near-infrared fluorescence (NIRF) imaging modalities. The applicability of MnO-PEG-Cy5.5 NPs as a dual-modal (MR/NIRF) imaging nanoprobe for the detection of brain gliomas was investigated. In vivo MR contrast enhancement of the MnO-PEG-Cy5.5 nanoprobe in the tumor region was demonstrated. Meanwhile, whole-body NIRF imaging of glioma bearing nude mouse exhibited distinct tumor localization upon injection of MnO-PEG-Cy5.5 NPs. Moreover, ex vivo CLSM imaging of the brain slice hosting glioma indicated the preferential accumulation of MnO-PEG-Cy5.5 NPs in the glioma region. Our results therefore demonstrated the potential of MnO-PEG-Cy5.5 NPs as a dual-modal (MR/NIRF) imaging nanoprobe in improving the diagnostic efficacy by simultaneously providing anatomical information from deep inside the body and more sensitive information at the cellular level.

Topics: Animals; Brain; Carbocyanines; Contrast Media; Fluorescence; Glioma; Infrared Rays; Magnetic Resonance Imaging; Male; Manganese Compounds; Mice; Mice, Nude; Molecular Imaging; Nanoparticles; Neoplasms, Experimental; Oxides; Particle Size; Polyethylene Glycols; Surface Properties

Lipopolymer 49, a solid-phase synthesized T-shaped peptide-like oligoamide containing two central oleic acids, 20 aminoethane, and two terminal cysteine units, is identified as very potent and biocompatible small interfering RNA (siRNA) carrier for gene silencing in glioma cells. This carrier is combined with a novel targeting polymer 727, containing a precise sequence of Angiopep 2 targeting peptide, linked with 28 monomer units of ethylene glycol, 40 aminoethane, and two terminal cysteines in siRNA complex formation. Angiopep-polyethylene glycol (PEG)/siRNA polyplexes exhibit good nanoparticle features, effective glioma-targeting siRNA delivery, and intracellular siRNA release, resulting in an outstanding gene downregulation both in glioma cells and upon intravenous delivery in glioma model nude mice without significant biotoxicity. Therefore, this novel siRNA delivery system is expected to be a promising strategy for targeted and safe glioma therapy.

Topics: Adaptor Proteins, Signal Transducing; Animals; Apoptosis Regulatory Proteins; Brain; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Disease Models, Animal; Down-Regulation; Drug Delivery Systems; Electrophoresis, Agar Gel; Endocytosis; Gene Silencing; Gene Transfer Techniques; Glioma; Humans; Mice, Nude; Nanoparticles; Oxidation-Reduction; Peptides; Polyethylene Glycols; Polymerase Chain Reaction; Polymers; RNA, Messenger; RNA, Small Interfering; Transfection

To establish red-green dual-color fluorescence glioma model in nude mice and to explore its practical values.. CM-DiI-stained rat glioma C6 cells (C6-CM- DiI cells) expressing red fluorescence were inoculated into the brain of athymic nude mice expressing green fluorescence protein (NC-C57BL/6J-EGFP). Then the whole-body dual-color fluorescence imaging was detected dynamically. Finally whole brains of the tumor-bearing mice were removed and 5 µm thick serial frozen slices were made. Light microscopy, fluorescence microscopy and confocal laser scanning microscopy were performed to observe the transplanted tumor tissue structure and fluorescent cells.. Tumor mass with red fluorescence increased gradually under continuous in-vivo fluorescence imaging monitoring. Under the fluorescence microscope, cells with red, green and yellow fluorescence were observed in the frozen sections of transplanted tumor tissue and the mutual structural relationship among them could be defined. The tumor cells migration, implantation and cell fusion between transplanted tumor cells and host cells could be observed. It could be distinguished according to the fluorescence, that blood vessels of tumor-origin displayed red fluorescence, blood vessels of host-origin displayed green fluorescence and mosaic blood vessels appeared yellow fluorescence. It was depicted that host innate astrocytes and oligodendrocytes in the microenvironment at the tumor periphery could be activated and dedifferentiated into nestin-positive cells.. In contrast to traditional animal model, the dual-color fluorescence imaging of nude mouse models of glioma possesses enormous advantages in investigating tumor mass in-vivo fluorescence imaging, tumor cells migration and metastasis, tumor angiogenesis and reactive activation of host innate cells in the microenvironment at tumor periphery, thus, has highly practical application value.

Topics: Animals; Astrocytes; Brain Neoplasms; Carbocyanines; Cell Fusion; Cell Line, Tumor; Cell Movement; Disease Models, Animal; Fluorescent Dyes; Glioma; Green Fluorescent Proteins; Luminescent Proteins; Mice; Mice, Inbred C57BL; Mice, Nude; Microscopy, Confocal; Microscopy, Fluorescence; Neoplasm Transplantation; Neovascularization, Pathologic; Nestin; Oligodendroglia; Rats; Red Fluorescent Protein

Glioma is the most common primary brain tumor and causes a disproportionate level of morbidity and mortality across a wide range of individuals. From previous clinical practices, definition of glioma margin is the key point for surgical resection. In order to outline the exact margin of glioma and provide a guide effect for the physicians both at pre-surgical planning stage and surgical resection stage, pH/temperature sensitive magnetic nanogels conjugated with Cy5.5-labled lactoferrin (Cy5.5-Lf-MPNA nanogels) were developed as a promising contrast agent. Due to its pH/te mperature sensitivity, Cy5.5-Lf-MPNA nanogels could change in its hydrophilic/hydrophobic properties and size at different pH and temperatures. Under physiological conditions (pH 7.4, 37 °C), Cy5.5-Lf-MPNA nanogels were hydrophilic and swollen, which could prolong the blood circulation time. In the acidic environment of tumor tissues (pH 6.8, 37 °C), Cy5.5-Lf-MPNA nanogels became hydrophobic and shrunken, which could be more easily accumulated in tumor tissue and internalized by tumor cells. In addition, lactoferrin, an effective targeting ligand for glioma, provides active tumor targeting ability. In vivo studies on rats bearing in situ glioma indicated that the MR/fluorescence imaging with high sensitivity and specificity could be acquired using Cy5.5-Lf-MPNA nanogels due to active targeting function of the Lf and enhancement of cellular uptake by tailoring the hydrophilic/hydrophobic properties of the nanogels. With good biocompatibility shown by cytotoxicity assay and histopathological analysis, Cy5.5-Lf-MPNA nanogels are hopeful to be developed as a specific and high-sensitive contrast agent for preoperative MRI and intraoperative fluorescence imaging of glioma.

Topics: Acrylic Resins; Animals; Biocompatible Materials; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Fluorescence; Glioma; History, 20th Century; Hydrogen-Ion Concentration; Lactoferrin; Magnetic Phenomena; Magnetic Resonance Imaging; Male; Materials Testing; Mice; Nanogels; NIH 3T3 Cells; Particle Size; Polyethylene Glycols; Polyethyleneimine; Rats; Rats, Wistar; Staining and Labeling; Temperature

Ultrasound (US) and microbubbles can be used to facilitate cellular uptake of drugs through a cavitationinduced enhancement of cell membrane permeability. The mechanism is, however, still incompletely understood. A direct contact between microbubbles and cell membrane is thought to be essential to create membrane perturbations lasting from seconds to minutes after US exposure of the cells. A recent study showed that the effect may even last up to 8 h after cavitation (with residual permeability up to 24 h after cavitation). In view of possible membrane damage, the purpose of this study was to further investigate the evolution of cell viability in the range of the 24-h temporal window. Furthermore, a description of the functional changes in tumor cells after US exposure was initiated to obtain a better understanding of the mechanism of membrane perturbation after sonication with microbubbles. Our results suggest that US does not reduce cell viability up to 24 h post-exposure. However, a perturbation of the entire cell population exposed to US was observed in terms of enzymatic activity and characteristics of the mitochondrial membrane. Furthermore, we demonstrated that US cavitation induces a transient loss of cell membrane asymmetry, resulting in phosphatidylserine exposure in the outer leaflet of the cell membrane.

Topics: Acridine Orange; Animals; Annexin A5; Carbocyanines; Cell Line, Tumor; Cell Membrane; Cell Survival; Fluoresceins; Fluorescent Dyes; Glioma; Microbubbles; Microscopy, Fluorescence; Rats; Sonication; Tetrazolium Salts; Thiazoles

Glioblastoma (GBM), the most common malignant brain tumor, is among the most lethal neoplasms, with a median survival of approximately 1 year. Prognosis is poor since GBMs possess a strong migratory and highly invasive potential, making complete surgical resection impossible. Reduced expression of carboxypeptidase E (CPE), a neuropeptide-processing enzyme, in a cell death-resistant glioma cell line and lower CPE expression levels in the cohort of GBM samples of The Cancer Genome Atlas compared to normal brain control specimens prompted us to analyze the function of CPE as a putative tumor suppressor gene. In our samples, CPE was also reduced in GBM compared to normal brain with the strongest loss in cells surrounding hypoxic tumor areas as well as in most glioma cell lines and primary glioma cells. In our cohort of glioma patients, loss of CPE predominantly occurred in glioblastomas and was associated with worse prognosis. In glioma cells, CPE overexpression was significantly reduced, whereas knockdown or inhibition enhanced glioma cell migration and invasion. The decreased migratory potential following CPE overexpression was paralleled by altered cellular morphology, promoting a transition to focal adhesions and associated stress fibers. In contrast to the decreased migration, high CPE levels were associated with higher proliferative rates. As microenvironmental regulation cues, we identified CPE as being downregulated upon hypoxia or glucose deprivation. Our findings indicate an oxygen- and nutrition-dependent anti-migratory, but pro-proliferative role of CPE in gliomas with prognostic impact for patient survival, thereby contributing to the understanding of the "go or grow" hypothesis in gliomas.

Topics: Animals; Brain Neoplasms; Carbocyanines; Carboxypeptidase H; Cell Adhesion; Cell Hypoxia; Cell Line, Tumor; Cell Movement; Cell Proliferation; Disease Models, Animal; Gene Expression Regulation, Neoplastic; Glial Fibrillary Acidic Protein; Glioma; Glucose; Humans; Mice; Mice, Inbred C57BL; Neoplasm Invasiveness; RNA, Messenger; RNA, Small Interfering; Stress, Physiological; Succinates; Survival Analysis; Time Factors

To further understand the biological significance of amplifications for glioma development and recurrencies, we characterized amplicon frequency and size in low-grade glioma and amplicon stability in vivo in recurring glioblastoma. We developed a 12q13-21 amplicon-specific genomic microarray and a bioinformatics amplification prediction tool to analyze amplicon frequency, size, and maintenance in 40 glioma samples including 16 glioblastoma, 10 anaplastic astrocytoma, 7 astrocytoma WHO grade 2, and 7 pilocytic astrocytoma. Whereas previous studies reported two amplified subregions, we found a more complex situation with many amplified subregions. Analyzing 40 glioma, we found that all analyzed glioblastoma and the majority of pilocytic astrocytoma, grade 2 astrocytoma, and anaplastic astrocytoma showed at least one amplified subregion, indicating a much higher amplification frequency than previously suggested. Amplifications in low-grade glioma were smaller in size and displayed clearly different distribution patterns than amplifications in glioblastoma. One glioblastoma and its recurrencies revealed an amplified subregion of 5 Mb that was stable for 6 years. Expression analysis of the amplified region revealed 10 overexpressed genes (i.e., KUB3, CTDSP2, CDK4, OS-9, DCTN2, RAB3IP, FRS2, GAS41, MDM2, and RAP1B) that were consistently overexpressed in all cases that carried this amplification. Our data indicate that amplifications on 12q13-21 (a) are more frequent than previously thought and present in low-grade tumors and (b) are maintained as extended regions over long periods of time.

Topics: Adult; Aged; Blotting, Southern; Carbocyanines; Child; Child, Preschool; Chromosomes, Artificial, Bacterial; Chromosomes, Human, Pair 12; Computational Biology; Cosmids; DNA, Neoplasm; Female; Gene Amplification; Gene Expression Regulation, Neoplastic; Genes, Neoplasm; Glioma; Humans; In Situ Hybridization, Fluorescence; Male; Middle Aged; Oligonucleotide Array Sequence Analysis

Toward the goal of developing an optical imaging contrast agent that will enable surgeons to intraoperatively distinguish cancer foci from adjacent normal tissue, we developed a chlorotoxin:Cy5.5 (CTX:Cy5.5) bioconjugate that emits near-IR fluorescent signal. The probe delineates malignant glioma, medulloblastoma, prostate cancer, intestinal cancer, and sarcoma from adjacent non-neoplastic tissue in mouse models. Metastatic cancer foci as small as a few hundred cells were detected in lymph channels. Specific binding to cancer cells is facilitated by matrix metalloproteinase-2 (MMP-2) as evidenced by reduction of CTX:Cy5.5 binding in vitro and in vivo by a pharmacologic blocker of MMP-2 and induction of CTX:Cy5.5 binding in MCF-7 cells following transfection with a plasmid encoding MMP-2. Mouse studies revealed that CTX:Cy5.5 has favorable biodistribution and toxicity profiles. These studies show that CTX:Cy5.5 has the potential to fundamentally improve intraoperative detection and resection of malignancies.

Topics: Animals; Brain Neoplasms; Carbocyanines; Fluorescent Dyes; Glioma; Humans; Matrix Metalloproteinase 2; Mice; Microscopy, Fluorescence; Neoplasms; Neovascularization, Pathologic; Photons; Rats; Scorpion Venoms

The photophysical, electrochemical and spectroscopic characteristics of a conjugate of 3-devinyl-3-(1'-hexyloxyethyl)pyropheophorbide-a (HPPH) and a cyanine dye have been investigated both as a linked conjugate and as individual components. A photoexcitation of the HPPH moiety of the conjugate results in electron transfer from the singlet excited state of HPPH (1HPPH*) to the cyanine dye as well as that from the cyanine dye to 1HPPH* and is followed in both cases by facile back electron transfer to the ground state as indicated by time-resolved fluorescence and transient absorption measurements. Intersystem crossing to the triplet excited state (3HPPH*) competes with the electron transfer and 3HPPH* is quenched by oxygen to produce singlet oxygen (1O2), leading to specific covalent cross-linking of the nonactivated signal transducer and activator of transcription (STAT-3). In contrast to excitation of the HPPH moiety, photoexcitation of the cyanine dye unit results in a strong emission at 875 nm, which can be used for efficient tumor imaging. Compared to HPPH alone, the presence of the cyanine dye moiety in the conjugate produces a significantly higher uptake in tumors than in skin. Thus, the HPPH-cyanine dye conjugate can be used as a dual tumor imaging and photodynamic therapy agent.

Topics: Animals; Carbocyanines; Chlorophyll; Cross-Linking Reagents; Electrochemistry; Fluorescence; Glioma; Mice; Mice, Nude; Molecular Structure; Neoplasm Transplantation; Oxidation-Reduction; Photochemotherapy; Photosensitizing Agents; Singlet Oxygen; STAT3 Transcription Factor

This communication describes a design of cell-permeable near-infrared fluorogenic substrates for imaging beta-lactamase expression in living mammalian cells. This design is based on fluorescence energy transfer resonance and utilizes a peracetylated d-glucosamine to facilitate the transport of the near-infrared probe across cell membranes. This new type of fluorogenic probe may also be applied to image gene expression in living animals.

Topics: Acetylation; Animals; beta-Lactamases; Carbocyanines; Cell Line, Tumor; Cell Membrane Permeability; Cephalosporins; Fluorescence Resonance Energy Transfer; Fluorescent Dyes; Glioma; Glucosamine; Rats; Spectroscopy, Near-Infrared; Transfection

A multifunctional nanoprobe capable of targeting glioma cells, detectable by both magnetic resonance imaging and fluorescence microscopy, was developed. The nanoprobe was synthesized by coating iron oxide nanoparticles with covalently bound bifunctional poly(ethylene glycol) (PEG) polymer, which were subsequently functionalized with chlorotoxin and the near-infrared fluorescing molecule Cy5.5. Both MR imaging and fluorescence microscopy showed significant preferential uptake of the nanoparticle conjugates by glioma cells. Such a nanoprobe could potentially be used to image resections of glioma brain tumors in real time and to correlate preoperative diagnostic images with intraoperative pathology at cellular-level resolution.

Topics: Animals; Brain Neoplasms; Carbocyanines; Cell Line, Tumor; Ferric Compounds; Glioma; Humans; Magnetic Resonance Imaging; Microscopy, Confocal; Microscopy, Electron, Transmission; Microscopy, Fluorescence; Models, Chemical; Myocytes, Cardiac; Nanostructures; Nanotechnology; Phantoms, Imaging; Polyethylene Glycols; Rats; Scorpion Venoms

Although liposomes have been used as a vehicle for delivery of therapeutic agents in oncology, their efficacy in targeting brain tumors has been limited due to poor penetration through the blood-brain barrier. Because convection-enhanced delivery (CED) of liposomes may improve the therapeutic index for targeting brain tumors, we conducted a three-stage study: stage 1 established the feasibility of using in vivo magnetic resonance imaging (MRI) to confirm adequate liposomal distribution within targeted regions in normal rat brain. Liposomes colabeled with gadolinium (Gd) and a fluorescent indicator, 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine-5,5'-disulfonic acid [DiI-DS; formally DiIC(18)(3)-DS], were administered by CED into striatal regions. The minimum concentration of Gd needed for monitoring, correlation of infused volume with distribution volume, clearance of infused liposome containing Gd and DiI-DS (Lip/Gd/DiI-DS), and potential local toxicity were evaluated. After determination of adequate conditions for MRI detection in normal brain, stage 2 evaluated the feasibility of in vivo MRI monitoring of liposomal distribution in C6 and 9L-2 rat glioma models. In both models, the distribution of Lip/Gd/DiI-DS covering the tumor mass was well defined and monitored with MRI. Stage 3 was designed to develop a clinically relevant treatment strategy in the 9L-2 model by infusing liposome containing Gd (Lip/Gd), prepared in the same size as Lip/Gd/DiI-DS, with Doxil, a liposomal drug of similar size used to treat several cancers. MRI detection of Lip/Gd coadministered with Doxil provided optimum CED parameters for complete coverage of 9L-2 tumors. By permitting in vivo monitoring of therapeutic distribution in brain tumors, this technique optimizes local drug delivery and may provide a basis for clinical applications in the treatment of malignant glioma.

Topics: Animals; Antibiotics, Antineoplastic; Brain; Brain Neoplasms; Carbocyanines; Convection; Doxorubicin; Fluorescent Dyes; Gadolinium; Glioma; Gliosarcoma; Liposomes; Magnetic Resonance Imaging; Male; Rats; Rats, Sprague-Dawley; Tissue and Organ Procurement

Polyunsaturated fatty acids (PUFAs) can influence tumor growth and migration, both in vitro and in vivo. The PUFA gamma-linolenic acid (GLA) has been reported to improve the poor prognosis associated with human gliomas, although its effects at sublethal concentrations on residual cells postsurgery are poorly understood. The study investigated the effects sublethal PUFA doses (90 or 150 microM) may have on rat C6 glioma cell energy metabolism, since an adequate energy supply is essential for cell proliferation, migration, and apoptosis. Of note was the identification of mitochondrial heterogeneity in relation to the mitochondrial membrane potential (MMP), which has been suggested but unproven in previous studies. GLA and eicosapentaenoic acid (EPA) caused significant changes in cellular fatty acid composition and increased the percentage of cells with a low MMP after a 96-h exposure period. The presence of PUFAs inhibited C6 cell proliferation and migration, although apoptosis was not induced. The protein expression and activity of glucose-6-phosphate dehydrogenase was increased after 96-h incubation with 90 microM GLA and EPA and would allow redox regulation through increased NADPH production, permitting the maintenance of adequate intracellular reduced glutathione concentrations and limiting rates of lipid peroxidation and reactive oxygen species generation. Neither NADP(+)-isocitrate dehydrogenase nor NADP(+)-malate dehydrogenase activity responded to PUFAs, suggesting it is glucose-6-phosphate dehydrogenase that is the principal source of NADPH in C6 cells. These data compliment studies showing that higher concentrations of GLA induced glioma cell death and tumor regression and suggest that GLA treatment could be useful for the inhibition of residual cell proliferation and migration after surgical removal of the tumor mass.

Topics: Animals; Annexin A5; Benzimidazoles; Blotting, Western; Carbocyanines; Cell Movement; Cells, Cultured; Cytochromes c; DNA Fragmentation; Ethidium; Fatty Acids, Unsaturated; Fluorescent Antibody Technique; Fluorescent Dyes; Gas Chromatography-Mass Spectrometry; Glioma; Glucosephosphate Dehydrogenase; Membrane Potentials; Microscopy, Confocal; Mitochondria; Mitosis; Rats; Time Factors

Lipid-coated microbubbles (LCM) administered intravenously (i.v.) to rats bearing brain tumor, specifically enhance tumor visualization by ultrasound [1]. In order to understand the basis for this observation, we have examined the interactions of LCM with glioblastoma (C6) and gliosarcoma (9L) tumor cells in vivo and in vitro. LCM and LCM labeled with the fluorescent lipophilic dye 3,3'-dioctadecyloxacarbocyanine perchlorate (diO) were administered to rats bearing brain tumor. LCM and diO-labeled LCM were found principally at the tumor site with no evidence of label in the surrounding normal brain tissue. Analysis of the tumor by confocal laser scanning microscopy revealed that labeled LCM were inside the tumor cells. Similar analysis of LCM interactions with C6 and 9L cells in culture showed that LCM first adsorb at the surface of the cells, and with time became localized inside the cells. Binding and internalization proceeded faster at 37 degrees C than at room temperature (RT). Staining of live cells with N-(3-((2,4-dinitrophenyl)amino)propyl)-N-(3-aminopropyl) methylamine dihydrochloride (DAMP), a dye that recognizes acidic compartments, showed that the majority of internalized LCM was associated with compartments containing DAMP. If the same uptake mechanism were operative in vivo, it would indicate that a portion of LCM bypasses the reticuloendothelial system and become endocytosed directly by tumor cells.

Topics: Animals; Brain Neoplasms; Carbocyanines; Craniotomy; Dinitrobenzenes; Endocytosis; Fluorescent Dyes; Glioma; Gliosarcoma; Liposomes; Microscopy, Confocal; Microscopy, Fluorescence; Microspheres; Neoplasm Transplantation; Organelles; Rats; Rats, Inbred F344; Rats, Sprague-Dawley; Staining and Labeling; Tumor Cells, Cultured

Confrontation cultures between glioma spheroids and brain cell aggregates are well established in glioma research, and the model reflects several similarities to the in vivo brain tumour invasive process. The lipid-binding fluorescent carbocyanine dyes DiO (3,3'-dioctadecyloxacarbocyanine perchlorate) and DiI (1,1'-dioctadecyl-3,3,3,'3,'-tetramethylinocarbocyanine perchlorate) are widely used in cell biology as tracers for studying cell movement. Mature brain cell aggregates grown from fetal rat brain cells, and spheroids initiated from two glioma cell lines (GaMg and D-54Mg) were stained with DiO and DiI, respectively. Penetration of DiI and DiO into the tumour spheroids and brain aggregates was studied by confocal laser scanning microscopy (CLSM). After 48 h of dye exposures, the tracers had almost completely penetrated the tumour spheroids and brain aggregates. Light-microscopic sections of the specimens indicated that the dye incorporation had little effect on cellular morphology. Cell migration from DiI stained D-54Mg and GaMg spheroids was similar to that observed from unstained spheroids. Growth was also unaffected after 48 h of DiI exposure. Gioma cell invasion was assessed by CLSM using co-cultures of DiI -stained spheroids and DiO-stained brain cell aggregates. Optical sections revealed a gradual decrease in remaining brain volume, indicating a progressive invasive process. Single tumour cells were identified deep within the brain aggregates. In addition normal brain cells were also identified in the tumour spheroids. It is concluded that vital staining can be used to identify both normal cells and tumour cells during tumour cell invasion in vitro. The method may provide the possibility for studying the kinetics of single normal and tumour cell movement in individual tumour/brain co-cultures.

Topics: Animals; Brain; Brain Neoplasms; Carbocyanines; Cell Aggregation; Cell Division; Cell Movement; Coculture Techniques; Fetus; Fluorescent Dyes; Glioma; Humans; Microscopy, Confocal; Neoplasm Invasiveness; Rats; Rats, Inbred Strains; Tumor Cells, Cultured

Low-density lipoprotein (LDL) is a carrier of the cholesterol found in human plasma. Cells utilize cholesterol for membrane synthesis by taking up LDL via receptor-mediated endocytosis. In the present study, interactions of LDL with human malignant glioma cell lines (U-251 MG and KMG-5) were investigated biochemically and morphologically. The LDL, labeled with the fluorescent dyes 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (DiI) and fluorescein isothiocyanate (FITC), was internalized by both cell processes and cell bodies. Reductive methylation of DiI-labeled LDL, which abolishes the ability of the cell to bind to the LDL receptor, prevented the internalization of the cholesterol moiety of LDL. Cellular binding of 125I-LDL to U-251 MG cells at 4 degrees C revealed the presence of a specific saturable-associated receptor (dissociation constant (Kd) approximately 38 micrograms/ml). Endocytic uptake of 125I-LDL or 3H-cholesterol oleate-labeled LDL (3H-LDL) at 37 degrees C demonstrated the cell-associated 125I-LDL and 3H-LDL increase. The intracellular degradation of protein moiety increased linearly with time. Reductive methylation of 3H-LDL led to a remarkable decrease in the cell-associated cholesterol moiety of LDL. The difference in uptake of the cholesterol moiety of LDL between U-251MG cells and KMG-5 cells showed that the U-251MG cells, which proliferate more actively than KMG-5 cells, take up more of the cholesterol moiety of LDL than do the KMG-5 cells. Thus, LDL cholesterol seems to be endocytosed predominantly via the LDL receptor present on the plasma membrane of malignant glioma cells. In addition, for growth, these cells may require large amounts of the cholesterol moiety of LDL.

Topics: Brain Neoplasms; Carbocyanines; Cholesterol, LDL; Endocytosis; Fluorescein-5-isothiocyanate; Fluoresceins; Glioma; Humans; Microscopy, Fluorescence; Radioligand Assay; Receptors, LDL; Thiocyanates; Tumor Cells, Cultured

Topics: Benzothiazoles; Carbocyanines; Cations; Cell Line; Fluorescent Dyes; Glioma; Hybrid Cells; Membrane Potentials; Neoplasms, Experimental; Neuroblastoma; Prostaglandins; Prostaglandins D; Serotonin