Targeting Specific Receptors Research Articles

Tracking Effector T Cell Dynamics and Immune Inhibitory Receptors in Patients with Acute Myeloid Leukemia (AML)

Background: Targeting specific immune inhibitory receptors (iRs) with monoclonal antibodies has led to paradigm-shifting treatment practices in a variety of solid cancers. These advances were in part driven by tremendous progress in phenotypic and functional characterization of altered iR expression patterns and memory T cell differentiation states such as exhaustion and senescence. Effector T cell dynamics and iR expression patterns in AML patients (pts) at diagnosis and after induction chemotherapy are not well understood and, if deciphered, are poised to be critically important for optimal integration of therapeutic blockade of various iRs in the clinic.Methods: We analyzed T cell dynamics and iR expression in peripheral blood (PB, n=45) and bone marrow (BM, n=38) cells from 49 pts (median age 60, range 21-76) with newly diagnosed AML. After induction, 36 (73%) pts entered complete remission (CR) whereas 13 (27%) were non responders (NR). Samples were collected at diagnosis, upon recovery after induction and following consolidation/salvage chemotherapy. Using multi-parameter flow cytometry, we characterized the differentiation status (CD45RA, CCR7), and the expression of co-stimulatory receptors (CD27, CD28) and iRs. Our gating strategy excluded NK T cells (CD3+ CD56+) from downstream analyses. Co-expression of iRs was analyzed in combination of 3 (2B4, BTLA, TIM3) or 4 (KLRG-1, CD57, PD-1 and CD160) markers. As a control, we used PB (n=41)/BM (n=16) lymphocytes from healthy controls (HC). Percentage of cells expressing specific markers were log transformed and modeled with mixed-effect linear regression models. Differential response outcomes over time were tested with interaction terms. Co-expression of multiple iRs was also analyzed with SPICE software version 5.3.Results: At diagnosis, AML pts showed significantly lower median frequency of CD8+ naïve (CD45RA+ CCR7+) T cells in PB, but higher frequencies of terminal differentiated effector memory (TEMRA; CD45RA+ CCR7-) and phenotypically senescent CD8+ CD27- CD28- CD57+ T cells. Significantly higher percentages of PB CD4+ and CD8+ T cells were found to express PD1 and 2B4 compared to HC. Additionally, the frequency of PB CD8+ T cells co-expressing 2-4 iRs was significantly higher in the PB of AML pts (Fig.1). Surprisingly, in contrast to PB, the only significant finding in the BM of AML pts at diagnosis was increased frequency of CD8+ CD27- CD28- CD57+ T cells (p<0.001) compared to HC.At the time of hematopoietic recovery from chemotherapy, TEMRAs and CD8+ CD27- CD28- CD57+ T cells significantly decreased in PB and BM of AML pts, compared to pretreatment levels. However, if analyzed by response, frequencies of these populations declined only in CR pts (p<0.001), but remained unchanged in NR pts. Analysis of iR co-expression in relation to the response to chemotherapy and time revealed that the frequency of CD8+ T cells co-expressing multiple IRs decreases in CR pts but increases in NR pts. These response-associated changes in iR co-expression were observed only in BM while, in PB, the iR co-expression profile remained unchanged irrespective of response.Finally, we assessed the effect of diverse pre-treatment factors on T cell composition at AML diagnosis. We found that older age was associated with increased frequency of CD8+ T cells expressing the iR marker KLRG-1 and the senescent T cell phenotype CD8+ CD27- CD28- CD57+ (p<0.001) but age did not affect iR co-expression on T cells in either PB or BM. CMV seropositivity was associated with increased CD8+ TEMRAs in PB and CD8+ T cells co-expressing multiple iRs (mostly Tim3 and 2B4) in both compartments. The effect of sex, cytogenetic risk group, or ELN category was insignificant.Conclusion: Our study provides critical insights into T cell differentiation and iR expression at diagnosis and during the course of treatment in pts with AML. We have identified several dominant expression patterns suggesting that iR signatures are consistent with immune recognition of AML and their role in sculpting the effector T cell responses directed against AML cell populations. However, data need to be interpreted in the context of the anatomical compartment and non-inheritable variables such as CMV and age. While ongoing work is focused on the deciphering significance of IRs expression for the interpretation of T cell functionality, our data support the rationale for therapeutic blocking of iRs in AML. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Biotinylated Cubosomes: A Versatile Tool for Active Targeting and Codelivery of Paclitaxel and a Fluorescein-Based Lipid Dye.

The functionalization of cubosomes with biotin is reported here as an alternative method for the preparation of drug delivery systems capable of active targeting specific receptors that are (over)expressed by cancer cells. We describe the design, synthesis, assembly, and characterization of these novel cubosome nanoparticles by small-angle X-ray scattering (SAXS) and dynamic laser light scattering (DLS) and show their application to human adenocarcinoma cell line HeLa. These cubosomes are stabilized and functionalized with a novel, designed biotin-based block copolymer and are able to simultaneously transport paclitaxel, a potent anticancer drug, and a hydrophobic fluorescent dye in the active targeting of cancer cells. Such biotinylated cubosomes are potentially applicable in diagnosis, drug delivery, and monitoring of the therapeutic response for active targeting versus cancer cells.

Assessment of the enhancement of PLGA nanoparticle uptake by dendritic cells through the addition of natural receptor ligands and monoclonal antibody

Targeting of specific receptors on antigen-presenting cells is an appealing prospect in the production of novel nanoparticulate vaccines. In particular, the targeting of vaccines to dendritic cell (DC) subsets has been shown in models to significantly improve the induction of immune responses. This paper describes the evaluation of natural ligands, mannan and chitosan, and monoclonal antibodies as targeting motifs to enhance uptake of PLGA nanoparticle carriers by bovine DCs. To assess enhancement of uptake after the addition of natural ligands a bovine monocyte derived DC (MoDC) model was used. For the assessment of monoclonal antibody targeting, the model was expanded to include afferent lymph DCs (ALDCs) in a competitive uptake assay. Mannan, proved unsuccessful at enhancing uptake or targeting by MoDCs. Chitosan coated particle uptake could be impeded by the addition of mannan suggesting uptake may be mediated through sugar receptors. Inclusion of monoclonal antibodies specific for the DEC-205 (CD205) receptor increased the number of receptor expressing DCs associated with particles as well as the number of particles taken up by individual cells. These results support the further evaluation of active targeting of nanovaccines to DCs to enhance their immunogenicity in cattle and other large mammalian species including humans.

Computationally modelled receptors for drug monitoring using an optical based biomimetic SPR sensor

Molecularly imprinted polymers (MIPs) were designed using computational simulation for the synthesis of high affinity synthetic receptors to be used for drug recognition and detection in combination with optical based biosensors. The monomer library was screened for the target drug metoprolol based on binding energy between each monomer and the target for the selection of best monomers to develop a successful production recipe. Metoprolol-specific imprinted polymers were then produced using a solid phase synthesis method as nanoparticles. The quality and size of the produced receptors were characterized prior to the affinity testing through a surface plasmon resonance (SPR)-based optical biosensor. High quality synthetic receptors were obtained with the best monomer found using the molecular modelling program. The size of the receptors was found to be ∼169.4nm±3.5 with polydispersity index of 0.3. The target specific receptor was then immobilized on the sensor surface via covalent coupling. Metoprolol which is a β-blocker drug was successfully detected in the range of 1.9ngmL−1–1μgmL−1 with correlation coefficient of 0.97. A regeneration method was developed for the sensor reuse and cross-reactivity studies were conducted using the control drugs. Kinetic data analysis was performed through SPR-2 and Biacore 3000 analysers to determine the affinity between the recognition element and metoprolol. The dissociation constant was found to be 1.35×10−10M using Langmuir binding model. The size and quality of the synthetic receptor were periodically measured during six months to determine the stability. The size of the receptors was found nearly same (171.1nm±5.4) and they still showed high activity for sensor assays. The receptor affinity and capacity towards metoprolol were also confirmed by solid phase extraction (SPE) method coupled with LC–MS. The achieved results highlight the success of computationally modelled receptor with SPR biosensor for pharmaceuticals detection and monitoring. The application of this work can be extended to the separation and detection of drugs from water samples, providing useful information and separation techniques for ecotoxicity studies.

Negatively charged AuNP modified with monoclonal antibody against novel tumor antigen FAT1 for tumor targeting.

BackgroundHerein, we demonstrated the use of a newly generated anti FAT1 antibody (clone mAB198.3) for intracellular delivery of anionic gold NPs, to form active targeting Au nanoparticles with high payload characteristics.MethodsIn vitro characterizations were determined by DLS, confocal microscopy, TEM, western blot, MALDI-TOF MS/MS analysis, MTT, ICP-MS and flow cytometry analysis. In vivo targeting efficacy was investigated by in vivo bio-imaging study and ICP-MS.ResultsThe specificity of the FAT1 recognition in colon cancer was confirmed by pre-adsorbing mAb198.3, adsorption dramatically abolished the antibody reactivity on colon cancer, thus confirming the binding specificity. The DLS size distribution profile of the AuCOOH, AuCOOH(Cy5)_ mAb198.3, AuCOOH(Cy5)_isotype has showed that the modified gold nanoparticles are well dispersed in water, PBS buffer and cell culture medium with 10 % FBS. By TEM measurement, the size of Au nanoparticles with spherical morphology is about 10–20 nm. AuCOOH_198.3 NPs were stable in an acidic environment, as well as in PBS buffer, cell culture media and media with 10 % serum. MTT results revealed that Au nanoparticles have well biocompatibility. TEM results indicated that conjugation of mAb198.3 on Au nanoparticles can be an effective delivery vehicle for negatively charged gold nanoparticles and increased its intracellular transport. It was also demonstrated by confocal microscopy that AuCOOH(Cy5)_mAb198.3 could attach to the cell membrane in very short time, then gradually delivered into cells. After 4 h incubation, almost all AuCOOH(Cy5)_mAb198.3 have been uptaken into or surrounding the cytoplasm and nucleus. In vivo results showed that only about 20 % of AuCOOH accumulated in tumor site due to EPR effect, while nearly 90 % of AuCOOH_mAb198.3 was found in tumor, providing sufficient evidence for receptor-specific targeting by mAb198.3.ConclusionAccording to in vitro and in vivo research results, the intracellular uptake of negatively charged AuCOOH_mAB198.3 particles is enhanced to a greater extent. Thus, AuCOOH_mAb198.3 holds significant potential to improve the treatment of cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-015-0214-x) contains supplementary material, which is available to authorized users.

Assessing potential peptide targeting ligands by quantification of cellular adhesion of model nanoparticles under flow conditions

Sophisticated drug delivery systems are coated with targeting ligands to improve the specific adhesion to surface receptors on diseased cells. In our study, we developed a method with which we assessed the potential of peptide ligands to specifically bind to receptor overexpressing target cells. Therefore, a microfluidic setup was used where the cellular adhesion of nanoparticles with ligand and of control nanoparticles was observed in parallel under the same experimental conditions. The effect of the ligand on cellular binding was quantified by counting the number of adhered nanoparticles with ligand and differently labeled control nanoparticles on single cells after incubation under flow conditions. To provide easy-to-synthesize, stable and reproducible nanoparticles which mimic the surface characteristics of drug delivery systems and meet the requirements for quantitative analysis, latex beads based on amine-modified polystyrene were used as model nanoparticles. Two short peptides were tested to serve as targeting ligand on the beads by increasing the specific binding to HuH7 cells. The c-Met binding peptide cMBP2 was used for hepatocyte growth factor receptor (c-Met) targeting and the peptide B6 for transferrin receptor (TfR) targeting. The impact of the targeting peptide on binding was investigated by comparing the beads with ligand to different internal control beads: 1) without ligand and tailored surface charge (electrostatic control) and 2) with scrambled peptide and similar surface charge, but a different amino acid sequence (specificity control). Our results demonstrate that the method is very useful to select suitable targeting ligands for specific nanoparticle binding to receptor overexpressing tumor cells. We show that the cMBP2 ligand specifically enhances nanoparticle adhesion to target cells, whereas the B6 peptide mediates binding to tumor cells mainly by nonspecific interactions. All together, we suggest that cMBP2 is a suitable choice for specific receptor targeting whereas the peptide B6 should not be considered as specific targeting moiety.

Expression of somatostatin, dopamine, progesterone and growth hormone receptor mRNA in canine cortisol-secreting adrenocortical tumours

Cortisol-secreting adrenocortical tumours (AT) in dogs are characterised by uncontrolled growth and excessive cortisol secretion. Dysregulated hormone receptor expression might be involved in tumour growth and hypersecretion of cortisol. The relative mRNA expression of growth hormone receptor, progesterone receptor, somatostatin receptors (SSTR1–3) and dopamine receptors (DRD1–2 and DRD5) was evaluated in 36 canine ATs and 15 adrenal glands obtained from healthy dogs. Compared with normal adrenal tissue, DRD2 mRNA expression was relatively lower in carcinomas, while SSTR1 mRNA expression was lower in both adenomas and carcinomas. Both of these features might contribute to loss of inhibition of tumour growth and upregulation of cortisol secretion. In canine ATs that had recurred within 30 months of surgical adrenalectomy, a marked increase in expression of DRD1 mRNA was observed. Targeting of specific hormone receptors, expressed by ATs, might be exploited for therapy.

Novel Bifunctional Cyclic Chelator for (89)Zr Labeling-Radiolabeling and Targeting Properties of RGD Conjugates.

Within the last years 89Zr has attracted considerable attention as long-lived radionuclide for positron emission tomography (PET) applications. So far desferrioxamine B (DFO) has been mainly used as bifunctional chelating system. Fusarinine C (FSC), having complexing properties comparable to DFO, was expected to be an alternative with potentially higher stability due to its cyclic structure. In this study, as proof of principle, various FSC-RGD conjugates targeting αvß3 integrins were synthesized using different conjugation strategies and labeled with 89Zr. In vitro stability, biodistribution, and microPET/CT imaging were evaluated using [89Zr]FSC-RGD conjugates or [89Zr]triacetylfusarinine C (TAFC). Quantitative 89Zr labeling was achieved within 90 min at room temperature. The distribution coefficients of the different radioligands indicate hydrophilic character. Compared to [89Zr]DFO, [89Zr]FSC derivatives showed excellent in vitro stability and resistance against transchelation in phosphate buffered saline (PBS), ethylenediaminetetraacetic acid solution (EDTA), and human serum for up to 7 days. Cell binding studies and biodistribution as well as microPET/CT imaging experiments showed efficient receptor-specific targeting of [89Zr]FSC-RGD conjugates. No bone uptake was observed analyzing PET images indicating high in vivo stability. These findings indicate that FSC is a highly promising chelator for the development of 89Zr-based PET imaging agents.

Significance of GABA(A) receptor heterogeneity: clues from developing neurons.

Briefly after the landmark discovery by Hanns Möhler that GABA(A) receptors (GABA(A)R) are the site of action of benzodiazepine site ligands, their distribution in the rodent CNS during development was mapped by autoradiography, demonstrating early and widespread expression of GABA(A)R in the brain and spinal cord. Ten years later, the first studies using subunit-specific antibodies revealed unsuspected heterogeneity in the subunit composition of GABA(A)R in developing brain, with striking regional specificity and rapid changes in expression and subcellular localization correlating with the maturation of neuronal circuits. These data contributed to the wealth of evidence that GABAergic neurotransmission, acting both synaptically and extrasynaptically, modulates major steps of neuronal development (proliferation, migration, differentiation, and circuit formation). In immature neurons, GABA(A)R activation leads to neuronal depolarization and activation of Ca(2+) signals, which mediate many of the developmental effects of GABA. Therefore, GABA(A)R heterogeneity might be essential to fine-tune GABA actions in the dynamics of CNS maturation. Furthermore, since a disturbance of GABAergic function during ontogeny can potentially affect many aspects of CNS maturation and contribute to the etiology of major brain disorders, GABA(A)R heterogeneity provides a substrate for the development of a tailored pharmacology targeting specific receptor subtypes. This chapter provides a brief overview of these issues with a special focus on the seminal contributions of Hanns Möhler to the emergence of these concepts of fundamental relevance in today's neuroscience research and pharmacological developments.

RGD-conjugated solid lipid nanoparticles inhibit adhesion and invasion of αvβ3 integrin-overexpressing breast cancer cells.

αvβ3 integrin receptors expressed on cancer cell surfaces play a crucial role in promoting tumor angiogenesis and cancer cell metastasis. Thus, cyclic arginyl-glycyl-aspartic acid (cRGD) peptides have been explored as a αvβ3 integrin receptor-specific targeting moiety for the targeted delivery of nanoparticle-loaded therapeutics. However, our previous study showed that cyclic RGD could act as a double-edged sword that, on one hand, extended the retention of cRGD-modified solid lipid nanoparticles (RGD-SLNs) at αvβ3 integrin receptor overexpressing breast carcinoma, and yet on the other hand, decreased the amount of tumor accumulation of RGD-SLNs attributable to the greater uptake by the mononuclear phagocyte system (MPS). Therefore, we aimed to optimize the RGD-decorated nanoparticle systems for (1) inhibiting αvβ3 integrin receptor overexpressing tumor cell metastasis and (2) increasing nanoparticle accumulation to tumor site. SLNs with cRGD content ranging from 0 to 10 % mol of total polyethyleneglycol (PEG) chains were synthesized. The binding of RGD-SLNs with αvβ3 integrin receptors increased with increasing cRGD concentration on the nanoparticles. RGD-SLNs were demonstrated to inhibit MDA-MB-231 cell adhesion to fibronectin and invasion through Matrigel. In vivo whole-body fluorescence imaging revealed that 1 % cRGD on the SLNs' surface had maximum tumor accumulation with extended tumor retention among all formulations tested in an orthotopic MDA-MB-231/EGFP breast tumor model. This work has laid a foundation for further development of anticancer drug-loaded optimized cRGD nanoparticle formulations for the treatment of breast cancer metastasis.

Development of a receptor-targeted gene delivery system using CXCR4 ligand-conjugated cross-linking peptides.

Success in gene therapy greatly depends on the efficiency of nucleic acid delivery. Important features of the carriers for gene delivery should include an enhanced transfection ability, targeting of specific receptors and low toxicity. In the present study, we characterized CXCR4-targeted cross-linking peptides modified with an N-terminal fragment of chemokine stromal cell-derived factor-1α as carriers for gene delivery. We studied three variants of DNA/carrier complexes with different targeting ligand content. The physicochemical characteristics of the complexes, including their DNA-binding and protective ability, interaction with glycosaminoglycans and size, were determined. Transfection efficacy was studied in cell lines with different levels of CXCR4 expression (HeLa, A172, CHO, Е.А.hy926) and also in human mesenchymal stem cells (hMSCs). The influence of the ligand content on the efficacy of transfection was studied by means of chlorpromazine blockage of clathrin-mediated endocytosis, competition with CXCR4-antagonist AMD3100, and valproic acid treatment of hMSCs. CXCR4-targeted peptides were evaluated for their physicochemical properties and in vitro transfection capacities. Ligand-modified carriers were found to be 10- to 50-fold more effective than unmodified carriers in CXCR4-positive cells. By contrast, their transfection efficacy in CXCR4-negative cells was similar to unmodified carriers. Experiments with chlorpromazine demonstrated receptor-specific transfection in A172 cells. The transfection efficacy of CXCR4-targeted carriers in AMD3100-treated HeLa cells was reduced by two-fold compared to the untreated control. Valproic acid treatment resulted in a four- to 15-fold increase of transfection efficacy for ligand-modified carriers in hMSCs. CXCR4-targeted cross-linking peptides should be considered as useful tools for nonviral gene delivery into tumor and mesenchymal stem cells.

A novel bradykinin-related dodecapeptide (RVALPPGFTPLR) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis) exhibiting unusual structural and functional features.

Bradykinin-related peptides (BRPs) are significant components of the defensive skin secretions of many anuran amphibians, and these secretions represent the source of the most diverse spectrum of such peptides so far encountered in nature. Of the many families of bioactive peptides that have been identified from this source, the BRPs uniquely appear to represent homologues of counterparts that have specific distributions and receptor targets within discrete vertebrate taxa, ranging from fishes through mammals. Their broad spectra of actions, including pain and inflammation induction and smooth muscle effects, make these peptides ideal weapons in predator deterrence. Here, we describe a novel 12-mer BRP (RVALPPGFTPLR-RVAL-(L1, T6, L8)-bradykinin) from the skin secretion of the Fujian large-headed frog (Limnonectes fujianensis). The C-terminal 9 residues of this BRP (-LPPGFTPLR) exhibit three amino acid substitutions (L/R at Position 1, T/S at Position 6 and L/F at Position 8) when compared to canonical mammalian bradykinin (BK), but are identical to the kinin sequence present within the cloned kininogen-2 from the Chinese soft-shelled turtle (Pelodiscus sinensis) and differ from that encoded by kininogen-2 of the Tibetan ground tit (Pseudopodoces humilis) at just a single site (F/L at Position 8). These data would imply that the novel BRP is an amphibian defensive agent against predation by sympatric turtles and also that the primary structure of the avian BK, ornithokinin (RPPGFTPLR), is not invariant within this taxon. Synthetic RVAL-(L1, T6, L8)-bradykinin was found to be an antagonist of BK-induced rat tail artery smooth muscle relaxation acting via the B2-receptor.

Inhibitory Effect of Prostaglandin E2 on the Migration of Nasal Fibroblasts

Objectives: Fibroblast migration is crucial for normal wound repair after sinonasal surgery. Prostaglandin E2 (PGE2) is a potent inhibitor of fibroblast functions including chemotaxis, proliferation, and matrix production. The purpose of this study was to determine whether PGE2 affects the migration of nasal fibroblasts and to investigate the mechanism of action of PGE2 on nasal fibroblasts. Methods: Primary cultures of nasal fibroblasts were established from inferior turbinate samples. Fibroblast migration was evaluated with scratch assays. Reverse transcription-polymerase chain reaction was performed for E-prostanoid (EP)1, EP2, EP3 and EP4 receptors. EP receptor-selective agonists and antagonists were used to evaluate receptor functions. Stimulatory G (Gs) proteins were activated to evaluate mechanisms. Intracellular cyclic adenosine monophosphate (cAMP) levels were measured by enzyme-linked immunosorbent assay, and fibroblast cytoskeletal structures were visualized with immunocytochemistry. Results: PGE2 significantly reduced the migration of nasal fibroblasts. Agonists selective for the EP2 and EP4 receptors significantly reduced the nasal fibroblast migration. Antagonists of the EP2 and EP4 receptors inhibited the effect of PGE2 on nasal fibroblast migration. Activation of Gs protein and adenyl cyclase reduced nasal fibroblast migration. Conclusions: PGE2 inhibited the migration of nasal fibroblasts via the EP2 and EP4 receptors, and this inhibition was mediated by cAMP elevation. Targeting specific EP receptors could offer therapeutic opportunities for conditions such as delayed wound healing after nasal surgery.

Chemokine Regulation of Neutrophil Infiltration of Skin Wounds

Significance: Efficient recruitment of neutrophils to an injured skin lesion is an important innate immune response for wound repair. Defects in neutrophil recruitment lead to impaired wound healing. Recent Advances: Chemokines and chemokine receptors are known to regulate neutrophil recruitment. Recent research advances reveal more mechanistic details about the regulation of chemokines and chemokine receptors on neutrophil egress from bone marrow, transmigration into the wound site, spatial navigation toward the necrotic skin tissue, and apoptosis-induced clearance by efferocytosis. Critical Issues: Skin injury triggers local and systemic alterations in the expression of multiple chemotactic molecules and the magnitude of chemokine receptor-mediated signaling. The responses of a number of CXC and CX3C chemokines and their receptors closely associate with the temporal and spatial recruitment of neutrophils to wound sites during the inflammatory phase and promote the clearance of necrotic neutrophils during the transition into the proliferative phase. Functional aberrancy in these chemokines and chemokine receptor systems is recognized as one of the important mechanisms underlying the pathology of impaired wound healing. Future Directions: Future research should aim to investigate the therapeutic modulation of neutrophil activity through the targeting of specific chemokines or chemokine receptors in the early inflammatory phase to improve clinical management of wound healing.

Cardiology patient page. Breast cancer chemotherapy and your heart.

Breast cancer is the most commonly diagnosed cancer in women. One in 8 women is diagnosed with breast cancer. Over the past 2 decades, death from breast cancer has decreased. As a result, today there are ≈3 000 000 breast cancer survivors in the United States, a number that will increase in the coming years. Increased breast cancer survivorship has occurred in part as a result of improved breast cancer treatments. Breast cancer treatments include the following: 1. Chemotherapy involves drugs that are intended to kill the cancer cells or stop them from dividing. In many cases, chemotherapy includes a class of chemotherapies called anthracyclines . 2. Surgery involves removal of the breast tumor. How much of the breast is removed depends on the size of the tumor and location of tumor and other factors. 3. Radiation uses high-energy radioactive beams and often accompanies surgery to lower the chance cancer will recur in the breast or nearby lymph nodes. 4. Targeted therapies target specific receptors that are highly expressed on cancer cells. For instance, some breast cancer types have a receptor called HER2. As a result, novel therapies have been developed that target HER2. One such example is trastuzumab (Herceptin). 5. Breast cancer treatments are often used in combination to provide the highest chance for a cure. Although these therapies have increased the survival of cancer patients, some may cause cardiotoxicity or damage to the heart. Cardiotoxicity can occur in various forms and can include damage to the heart muscle itself, the heart arteries, or the heart …

Potentials and challenges of active targeting at the tumor cells by engineered polymeric nanoparticles.

Tumor targeted therapy has brought a new hope to the cancer patients. With the recent advances in nanotechnology and growing knowledge on unique cancer biomarkers, it is now possible to manipulate the surface architecture of polymeric nanoscale delivery systems with targeting moieties, such as antibodies, antibody fragments, specific molecules, small peptides, RNA aptamers etc. to target specific receptors and antigens present exclusively or overexpressed on the tumor cell surface or on the tumor endothelial cell surface. These modified polymeric nanoparticles deliver the loaded chemotherapeutics preferentially to the tumor tissue and not to the healthy tissue. This ensures highly targeted treatment without severe side effects which are normally experienced by the cancer patients in case of conventional chemotherapy. Such specifically constructed polymeric nanocarriers with improved tumor targeting profile are now regarded as engineered polymeric nanoparticles, which have become one of the prime areas of drug delivery research in recent times. This review describes specific approaches used in recent years to construct engineered polymeric nanoparticles, their emerging potential for cancer therapy and recent advances in tumor targeting. An equal attention has been devoted to the fundamental problems encountered in practical fields which limit their clinical use and industrial production.

Inhibitory effect of prostaglandin E(2) on the migration of nasal fibroblasts.

Fibroblast migration is crucial for normal wound repair after sinonasal surgery. Prostaglandin E2 (PGE2) is a potent inhibitor of fibroblast functions including chemotaxis, proliferation, and matrix production. The purpose of this study was to determine whether PGE2 affects the migration of nasal fibroblasts and to investigate the mechanism of action of PGE2 on nasal fibroblasts. Primary cultures of nasal fibroblasts were established from inferior turbinate samples. Fibroblast migration was evaluated with scratch assays. Reverse-transcription polymerase chain reaction was performed for E prostanoid (EP) 1, EP2, EP3, and EP4 receptors. EP receptor-selective agonists and antagonists were used to evaluate receptor functions. Stimulatory G (Gs) proteins were activated to evaluate mechanisms. Intracellular cyclic adenosine monophosphate (cAMP) levels were measured by ELISA, and fibroblast cytoskeletal structures were visualized with immunocytochemistry. PGE2 significantly reduced the migration of nasal fibroblasts. Agonists selective for the EP2 and EP4 receptors significantly reduced the nasal fibroblast migration. Antagonists of the EP2 and EP4 receptors inhibited the effect of PGE2 on nasal fibroblast migration. Activation of Gs protein and adenyl cyclase reduced nasal fibroblast migration. PGE2 inhibited the migration of nasal fibroblasts via the EP2 and EP4 receptors, and this inhibition was mediated by cAMP elevation. Targeting specific EP receptors could offer therapeutic opportunities for conditions such as delayed wound healing after nasal surgery.

Endospanin 1 silencing in the hypothalamic arcuate nucleus contributes to sustained weight loss of high fat diet obese mice.

Leptin targets specific receptors (OB-R) expressed in the hypothalamus to regulate energy balance. Leptin decreases food intake in normal weight individuals, but this effect is blunted in obese subjects who are characterized by a state of leptin resistance. The prevention of leptin resistance is one of the major goals of obesity research. Recently, we identified endospanin 1 as a negative regulator of OB-R, which by interacting with OB-R retains the receptor inside the cell. We show here that in obese mice endospanin 1 is upregulated in the hypothalamic arcuate nucleus (ARC), the major brain structure involved in body weight regulation, suggesting that endospanin 1 is implicated in obesity development and/or the installation of leptin resistance. In contrast, silencing of endospanin 1 with lentiviral vectors in the ARC of obese mice fully restores leptin responsiveness when combined with a switch to ad libitum fed chow diet. The recovery of central leptin sensitivity is accompanied by sustained body weight loss and amelioration of blood lipid parameters and steatosis. Collectively, our results define endospanin 1 as a novel therapeutic target against obesity.

Establishing regional specificity of neuroestrogen action

The specificity of estrogen signaling in brain is defined at one level by the types and distributions of receptor molecules that are activated by estrogens. At another level, as our understanding of the neurobiology of the estrogen synthetic enzyme aromatase has grown, questions have emerged as to how neuroactive estrogens reach specific target receptors in functionally relevant concentrations. Here we explore the spatial specificity of neuroestrogen signaling with a focus on studies of songbirds to provide perspective on some as-yet unresolved questions. Studies conducted in both male and female songbirds have helped to clarify these interesting facets of neuroestrogen physiology.

Immune synapse targeting of specific recycling receptors by the intraflagellar transport system

T cell activation requires sustained signaling at the immune synapse, a specialized interface with the antigen-presenting cell (APC) that assembles following T cell antigen receptor (TCR) engagement by major histocompatibility complex (MHC)-bound peptide. Central to sustained signaling is the continuous recruitment of TCRs to the immune synapse. These TCRs are partly mobilized from an endosomal pool by polarized recycling. We have identified IFT20, a component of the intraflagellar transport (IFT) system that controls ciliogenesis, as a central regulator of TCR recycling to the immune synapse. Here, we have investigated the interplay of IFT20 with the Rab GTPase network that controls recycling. We found that IFT20 forms a complex with Rab5 and the TCR on early endosomes. IFT20 knockdown (IFT20KD) resulted in a block in the recycling pathway, leading to a build-up of recycling TCRs in Rab5(+) endosomes. Recycling of the transferrin receptor (TfR), but not of CXCR4, was disrupted by IFT20 deficiency. The IFT components IFT52 and IFT57 were found to act together with IFT20 to regulate TCR and TfR recycling. The results provide novel insights into the mechanisms that control TCR recycling and immune synapse assembly, and underscore the trafficking-related function of the IFT system beyond ciliogenesis.