Dual-targeting Strategy Research Articles

A dual-targeted hyaluronic acid-gold nanorod platform with triple-stimuli responsiveness for photodynamic/photothermal therapy of breast cancer

Multi-stimuli-responsive theranostic nanoplatform integrating functions of both imaging and multimodal therapeutics holds great promise for improving diagnosis and therapeutic efficacy. In this study, we reported a pH, glutathione (GSH) and hyaluronidase (HAase) triple-responsive nanoplatform for HER2 and CD44 dual-targeted and fluorescence imaging-guided PDT/PTT dual-therapy against HER2-overexpressed breast cancer. The nanoplatform was fabricated by functionalizing gold nanorods (GNRs) with hyaluronic acid (HA) bearing pendant hydrazide and thiol groups via Au-S bonds, and subsequently chemically conjugating 5-aminolevulinic acid (ALA), Cy7.5 and anti-HER2 antibody onto HA moiety for PDT, fluorescence imaging and active targeting, respectively. The resulting versatile nanoplatform GNR-HA−ALA/Cy7.5-HER2 had uniform sizes, favorable dispersibility, as well as pH, GSH and HAase triple-responsive drug release manner. In vitro studies demonstrated that HER2 and CD44 receptor-mediated dual-targeting strategy could significantly enhance the cellular uptake of GNR-HA−ALA/Cy7.5-HER2. Under near-infrared (NIR) irradiation, MCF-7 cells could efficiently generate reactive oxygen species (ROS) and heat, and be more efficiently killed by a combination of PDT and PTT as compared with individual therapy. Pharmacokinetic and biodistribution studies showed that the nanoplatform possessed a circulation half-life of 1.9 h and could be specifically delivered to tumor tissues with an accumulation ratio of 12.8%. Upon the fluorescence imaging-guided PDT/PTT treatments, the tumors were completely eliminated without obvious side effects. The results suggest that the GNR-HA−ALA/Cy7.5-HER2 holds great potential for breast cancer therapy. Statement of significanceA combination of photodynamic therapy (PDT) and photothermal therapy (PTT) is emerging as a promising cancer treatment strategy. However, its therapeutic efficacy is compromised by the nonspecific delivery and unintended release of photo-responsive agents. Herein, we developed a multifunctional theranostic nanoplatform GNR-HA−ALA/Cy7.5-HER2 with pH, glutathione and hyaluronidase triple-responsive drug release for HER2 and CD44 dual-targeted and fluorescence imaging-guided PDT/PTT therapy against breast cancer. We demonstrated that HER2 and CD44 receptors-mediated dual-targeting strategy significantly enhanced the cellular uptake of GNR-HA−ALA/Cy7.5-HER2. We also demonstrated that the combined PDT/PTT treatment had significantly superior antitumor effect than PDT or PTT alone both in vitro and in vivo. Therefore, GNR-HA−ALA/Cy7.5-HER2 could serve as a promising nanoplatform for HER2-positive breast cancer therapy.

Mitochondria and plasma membrane dual-targeted chimeric peptide for single-agent synergistic photodynamic therapy

Mitochondria and cell membrane play important roles in maintaining cellular activity and stability. Here, a single-agent self-delivery chimeric peptide based nanoparticle (designated as M-ChiP) was developed for mitochondria and plasma membrane dual-targeted photodynamic tumor therapy. Without additional carrier, M-ChiP possessed high drug loading efficacy as well as the excellent ability of producing reactive oxygen species (ROS). Moreover, the dual-targeting property facilitated the effective subcellular localization of photosensitizer protoporphyrin IX (PpIX) to generate ROS in situ for enhanced photodynamic therapy (PDT). Notably, plasma membrane-targeted PDT would enhance the membrane permeability to improve the cellular delivery of M-ChiP, and even directly disrupt the cell membrane to induce cell necrosis. Additionally, mitochondria-targeted PDT would decrease mitochondrial membrane potential and significantly promote the cell apoptosis. Both in vitro and in vivo investigations indicated that this combinatorial PDT in mitochondria and plasma membrane could achieve the therapeutic effect maximization with reduced side effects. The single-agent self-delivery system with dual-targeting strategy was demonstrated to be a promising nanoplatform for synergistic tumor therapy.

Anticancer activity and antibody-dependent cell-mediated cytotoxicity of novel anti-nucleolin antibodies

Nucleolin arises as a relevant target for cancer therapy, as it is overexpressed at the surface of cancer and angiogenic endothelial cells thus enabling a dual cellular targeting strategy. Immunotherapeutic strategies, albeit of proven therapeutic relevance, have been scarcely explored against this target. Therefore, this work aimed at engineering an anti-nucleolin VHH-based antibody capable of triggering anticancer immune responses. Herein, anti-nucleolin VHHs have been generated upon grafting F3 peptide-derived nucleolin-binding sequences onto a VHH CDR1 or CDR3. One of these nucleolin-binding CDR3-grafted VHH was subsequently fused to a human IgG1 Fc region, enabling a significant antibody-dependent cell-mediated cytotoxicity (ADCC). The generated anti-nucleolin VHH revealed increased binding and antiproliferative effects against cancer cells, relative to the parental VHH, while the VHH-Fc counterpart presented increased cytotoxicity relative to the corresponding VHH. This VHH-Fc also triggered an ADCC effect, in the nanomolar range, against a nucleolin-overexpressing cancer cell line. This effect was evidenced by a 2 or 1.7-fold increase of cell death, in the presence of PBMCs, relative to the parental VHH-Fc or the VHH counterpart, respectively. Overall, these formats represent the first anti-nucleolin VHHs and the first anti-nucleolin antibody with ADCC activity that have been successfully developed.

A dual-target strategy for the detection of Chlamydia trachomatis by real-time PCR

A dual-target strategy for the detection of Chlamydia trachomatis by real-time PCR

A dual-targeting strategy for enhanced drug delivery and synergistic therapy based on thermosensitive nanoparticles

The functionalized nanoparticles have been widely studied and reported as carriers of drug transport recently. Furthermore, many groups have focused more on developing novel and efficient treatment methods, such as photodynamic therapy and photothermal therapy, since both therapies have shown inspiring potential in the application of antitumor. The mentioned treatments exhibited the superiority of cooperative manner and showed the ability to compensate for the adverse effects caused by conventional monotherapy in proposed strategies. In view of the above descriptions, we formulated a thermosensitive drug delivery system, which achieved the enhanced delivery of cisplatin and two photosensitizers (ICG and Ce6) by dual-targeting traction. Drawing on the thin film hydration method, cisplatin and photosensitizers were encapsulated inside nanoparticles. Meanwhile, the targeting peptide cRGD and targeting molecule folate can be modified on the surface of nanoparticles to realize the active identification of tumor cells. The measurements of dynamic light scattering showed that the prepared nanoparticles had an ideal dispersibility and uniform particle size of 102.6 nm. On the basis of the results observed from confocal laser scanning microscope, the modified nanoparticles were more efficient endocytosed by MCF-7 cells as a contrast to SGC-7901 cells. Photothermal conversion-triggered drug release and photo-therapies produced a significant apoptosis rate of 85.9% on MCF-7 cells. The distinguished results made it believed that the formulated delivery system had conducted great efforts and innovations for the realization of concise collaboration and provided a promising strategy for the treatment of breast cancer.

Low-density lipoprotein-cholesterol lowering in individuals at intermediate cardiovascular risk: Percent reduction or target level?

Recommendations for blood cholesterol management differ across different guidelines. Lipid-lowering strategies based on low-density lipoprotein-cholesterol (LDL-c) percent reduction or target concentration may have different effects on the expected cardiovascular benefit in intermediate-risk individuals. We selected individuals between 40 and 75 years of age with 10-year risk for atherosclerotic cardiovascular disease (ASCVD) between 5.0% and <7.5% who underwent a routine health screening. For every subject, we simulated a strategy based on a 40% LDL-c reduction (S40% ) and another strategy based on achieving LDL-c target ≤100 mg/dL (Starget-100 ). The cardiovascular benefit was estimated assuming a 22% relative risk reduction in major cardiovascular events for each 39 mg/dL of LDL-c lowered. The study comprised 1756 individuals (94% men, 52 ± 5 years old). LDL-c and predicted 10-year ASCVD risk would be slightly lower in S40% compared to Starget-100 . The number needed to treat to prevent 1 major cardiovascular event in 10 years (NNT10 ) would be 56 with S40% and 66 with Starget-100 . S40% would prevent more events in individuals with lower baseline LDL-c, whereas Starget-100 would be more protective in those with higher LDL-c. A dual-target strategy (40% minimum LDL-c reduction and achievement of LDL-c ≤100 mg/dL) would be associated with outcomes similar to those expected with the S40% (NNT10 = 55). In an intermediate-risk population, cardiovascular benefit from LDL-c lowering may be optimized by tailoring the treatment according to the baseline LDL-c or by setting a dual-target strategy (fixed dose statin plus achievement of target LDL-c concentration).

Dual-modified natural high density lipoprotein particles for systemic glioma-targeting drug delivery

Therapeutic outcome for the treatment of glioma was often limited due to the two barriers involved: the blood-brain barrier (BBB) and blood-brain tumor barrier (BBTB). Therefore, the development of nanocarriers that possess both BBB and BBTB permeability and glioma-targeting ability is of great importance for the chemotherapy of glioma. New frontiers in nanomedicine are advancing the research of new biomaterials. Here we constructed a natural high-density lipoprotein particle (HDL)-based drug delivery system with the dual-modification of T7 and dA7R peptide ligand (T7/dA7R-HDL) to achieve the above goals. HDL, the smallest lipoprotein, plays a biological role and is highly suitable as a platform for delivering imaging and therapeutic agents. T7 is a seven-peptide ligand of transferrin receptors (TfR) capable of circumventing the BBB and then targeting glioma. dA7R is a d-peptide ligand of vascular endothelial growth factor receptor 2 (VEGFR 2) overexpressed on angiogenesis, presenting excellent glioma-homing property. 10-Hydroxycamptothecin (HCPT), a hydrophobic anti-cancer drug, was used as the model drug in this study. By combining the dual-targeting delivery effect, the dual-modified HDL displayed higher glioma localization than that of single ligand-modified HDL or free HCPT. After loading with HCPT, T7/dA7R-HDL showed the most favorable anti-glioma effect in vivo. These results demonstrated that the dual-targeting natural nanocarriers strategy provides a potential method for improving brain drug delivery and anti-glioma treatment efficacy.

Platelet-camouflaged nanococktail: Simultaneous inhibition of drug-resistant tumor growth and metastasis via a cancer cells and tumor vasculature dual-targeting strategy.

Multidrug resistance (MDR) poses a great challenge to cancer therapy. It is difficult to inhibit the growth of MDR cancer due to its chemoresistance. Furthermore, MDR cancers are more likely to metastasize, causing a high mortality among cancer patients. In this study, a nanomedicine RGD-NPVs@MNPs/DOX was developed by encapsulating melanin nanoparticles (MNPs) and doxorubicin (DOX) inside RGD peptide (c(RGDyC))-modified nanoscale platelet vesicles (RGD-NPVs) to efficiently inhibit the growth and metastasis of drug-resistant tumors via a cancer cells and tumor vasculature dual-targeting strategy.Methods: The in vitro immune evasion potential and the targeting performance of RGD-NPVs@MNPs/DOX were examined using RAW264.7, HUVECs, MDA-MB-231 and MDA-MB-231/ADR cells lines. We also evaluated the pharmacokinetic behavior and the in vivo therapeutic performance of RGD-NPVs@MNPs/DOX using a MDA-MB-231/ADR tumor-bearing nude mouse model.Results: By taking advantage of the self-recognizing property of the platelet membrane and the conjugated RGD peptides, RGD-NPVs@MNPs/DOX was found to evade immune clearance and target the αvβ3 integrin on tumor vasculature and resistant breast tumor cells. Under irradiation with a NIR laser, RGD-NPVs@MNPs/DOX produced a multipronged effect, including reversal of cancer MDR, efficient killing of resistant cells by chemo-photothermal therapy, elimination of tumor vasculature for blocking metastasis, and long-lasting inhibition of the expressions of VEGF, MMP2 and MMP9 within the tumor.Conclusion: This versatile nanomedicine of RGD-NPVs@MNPs/DOX integrating unique biomimetic properties, excellent targeting performance, and comprehensive therapeutic strategies in one formulation might bring opportunities to MDR cancer therapy.

Improving Tumor Specificity and Anticancer Activity of Dasatinib by Dual-Targeted Polymeric Micelles.

To improve tumor targetability and drug efficacy and decrease drug resistance of dasatinib (DSB), the multifunctional micellar nanoparticles that combined the matrix metalloproteinase 2 (MMP2)-sensitive tumor (site) targeting with folate receptor-mediated tumor (cell) targeting were developed. Two major functional polymers, polyethylene glycol (5000 Da)-MMP2-sensitive peptide-phosphoethanolamine (PEG5k-pp-PE) and folic acid-polyethylene glycol (2000 Da)-phosphoethanolamine (FA-PEG2k-PE), were synthesized to construct the dual-targeted micellar nanoparticles (MMP/FR micelles). In the absence of MMP2, the FA was shielded by PEG5k and the MMP/FR micelles showed low bioactivity. In the presence of MMP2, the nanoparticulate structure, stability, and cargo release profile of the MMP/FR micelles were not significantly affected, however, the MMP2-mediated PEG5k deshielding and FA exposure remarkably increased the cellular uptake and anticancer activity of the micelles in the MMP2 and FR expressing (MMP2+/FR+) cells, including multidrug resistant (MDR) cancer cells, rather than the MMP2- and FR- cells. In the 3D MDR tumor spheroids, the significant MMP2-dependent tissue penetration, uptake and cytotoxicity of the MMP/FR micelles were also observed. Furthermore, in the in vivo biodistribution study, the MMP2 and FR dual targeting strategy could significantly prolong the systemic circulation, decrease the nonspecific distribution in nontumor tissues, and increase the tumor accumulation of the polymeric micelles in a melanoma xenograft mouse model. The MMP2-sensitive FR-targeted micelles might have great potential as a tumor-targeted platform for delivery of molecular targeted therapeutics.

Trispecific antibodies for CD16A-directed NK cell engagement and dual-targeting of tumor cells.

Bispecific antibodies that redirect the lytic activity of cytotoxic immune effector cells, such as T- and NK cells, onto tumor cells have emerged as a highly attractive and clinically validated treatment modality for hematological malignancies. Advancement of this therapeutic concept into solid tumor indications, however, is hampered by the scarcity of targetable antigens that are surface-expressed on tumor cells but demonstrate only limited expression on healthy tissues. To overcome this limitation, the concept of dual-targeting, i.e. the simultaneous targeting of two tumor-expressed surface antigens with limited co-expression on non-malignant cells, with multispecific antibodies has been proposed to increase tumor selectivity of antibody-induced effector cell cytotoxicity. Here, a novel CD16A (FcγRIIIa)-directed trispecific, tetravalent antibody format, termed aTriFlex, is described, that is capable of redirecting NK cell cytotoxicity to two surface-expressed antigens. Using a BCMA/CD200-based in vitro model system, the potential use of aTriFlex antibodies for dual-targeting and selective induction of NK cell-mediated target cell lysis was investigated. Bivalent bispecific target cell binding was found to result in significant avidity gains and up to 17-fold increased in vitro potency. These data suggest trispecific aTriFlex antibodies may support dual-targeting strategies to redirect NK cell cytotoxicity with increased selectivity to enable targeting of solid tumor antigens.

Targeting the tumor and its associated stroma: One and one can make three in adoptive T cell therapy of solid tumors

Adoptive T cell therapy (ACT) has become a promising immunotherapeutic option for cancer patients. The proof for ACT therapeutic efficacy was first obtained with allogenic T cells and then reproduced with T cells isolated from patients’ tumor samples (i.e. tumor-infiltrating lymphocytes). It is now clear that specificity of ACT products can be educated by genetically engineering T cells with classical T Cell Receptors (TCR) or chimeric antigen receptors (CAR). To date a poor accessibility of the tumor mass and a hostile microenvironment, influenced by genetic and epigenetic instability, mainly limit ACT therapeutic efficacy in the case of solid tumors. Available data indicate that these hurdles might be overcome by combinatorial therapeutic strategies targeting the tumor and its associated stroma. Here we review some of the available dual targeting strategies focusing on given combination of TCR/CAR-redirected T cell products and their association with drugs targeting the tumor-vessel and/or epigenetic modifiers, with the ability to sensitize tumors to T cell recognition. Existing data have proven synergistic effects in combined settings (one and one can indeed make three) and suggest that further benefit might be achieved by additional combinatorial therapeutic approaches (could one+one+one make ten?) in ACT of solid tumor.

Dual Targeting of Mesenchymal and Amoeboid Motility Hinders Metastatic Behavior.

Commonly upregulated in human cancers, the scaffolding protein NEDD9/HEF1 is a known regulator of mesenchymal migration and cancer cell plasticity. However, the functional role of NEDD9 as a regulator of different migration/invasion modes in the context of breast cancer metastasis is currently unknown. Here, it is reported that NEDD9 is necessary for both mesenchymal and amoeboid individual cell migration/invasion in triple-negative breast cancer (TNBC). NEDD9 deficiency results in acquisition of the amoeboid morphology, but severely limits all types of cell motility. Mechanistically, NEDD9 promotes mesenchymal migration via VAV2-dependent Rac1 activation, and depletion of VAV2 impairs the ability of NEDD9 to activate Rac1. In addition, NEDD9 supports a mesenchymal phenotype through stimulating polymerization of actin via promoting CTTN phosphorylation in an AURKA-dependent manner. Interestingly, an increase in RhoA activity in NEDD9-depleted cells does not facilitate a switch to functional amoeboid motility, indicating a role of NEDD9 in the regulation of downstream RhoA signaling effectors. Simultaneous depletion of NEDD9 or inhibition of AURKA in combination with inhibition of the amoeboid driver ROCK results in an additional decrease in cancer cell migration/invasion. Finally, we confirmed that a dual targeting strategy is a viable and efficient therapeutic approach to hinder the metastasis of breast cancer in xenograft models, showcasing the important need for further clinical evaluation of this regimen to impede the spread of disease and improve patient survival.Implications: This study provides new insight into the therapeutic benefit of combining NEDD9 depletion with ROCK inhibition to reduce tumor cell dissemination and discovers a new regulatory role of NEDD9 in the modulation of VAV2-dependent activation of Rac1 and actin polymerization. Mol Cancer Res; 15(6); 670-82. ©2017 AACR.

A precision-guided MWNT mediated reawakening the sunk synergy in RAS for anti-angiogenesis lung cancer therapy.

Multi-walled carbon nanotube (MWNT) with its versatility has exhibited tremendous superiority in drug delivery. Despite plenty of researches on MWNT based delivery systems, precision-guided assistances to maximize their profitable properties are still lacking in substantive progress. We developed here a dual-targeting and co-delivery system based on MWNT for antiangiogenesis therapy in lung cancer which aimed at renin-angiotensin system (RAS) dysregulation by synergistically conducting angiotensin II type 1 receptor (AT1R) and type 2 receptor (AT2R) pathway. In this work, iRGD peptide connected to polyethyleneimine (PEI) was linked to MWNT skeleton, accompanying with candesartan (CD) conjugated to MWNT mediated by cystamine (SS). The functionalized MWNT is assembled with plasmid AT2 (pAT2) to form iRGD-PEI-MWNT-SS-CD/pAT2 complexes. iRGD and CD act as pilots for complexes to dually target symbolic ανβ3-integrin and AT1R both overexpressed on tumor angiogenic endothelium and lung cancer cell. CD as chemotherapy showed synergistic downregulation of VEGF when combining of pAT2 and efficiently inhibited angiogenesis. iRGD-PEI-MWNT-SS-CD/pAT2 complexes greatly appreciated drug activities by changing drug distribution and exhibited remarkable tumor growth suppression in A549 xenograft nude mice. Our work presents that such dual-targeting strategy highly improves the delivery performance of MWNT and open a new avenue for RAS related lung cancer therapy.

Dual inhibition of IGF1R and ER enhances response to trastuzumab in HER2 positive breast cancer cells.

Although HER2 targeted therapies have improved prognosis for HER2 positive breast cancer, HER2 positive cancers which co-express ER have poorer response rates to standard HER2 targeted therapies, combined with chemotherapy, than HER2 positive/ER negative breast cancer. Administration of hormone therapy concurrently with chemotherapy and HER2 targeted therapy is generally not recommended. Using publically available gene expression datasets we found that high expression of IGF1R is associated with shorter disease-free survival in patients whose tumors are ER positive and HER2 positive. IGF1R is frequently expressed in HER2 positive breast cancer and there is significant evidence for crosstalk between IGF1R and both HER2 and ER. Therefore, we evaluated the therapeutic potential of targeting ER and IGF1R in cell line models of HER2/ER/IGF1R positive breast cancer, using tamoxifen and two IGF1R targeted tyrosine kinase inhibitors (NVP-AEW541 and BMS-536924). Dual inhibition of ER and IGF1R enhanced growth inhibition in the four HER2 positive cell lines tested and caused an increase in cell cycle arrest in G1 in BT474 cells. In addition, combined treatment with trastuzumab, tamoxifen and either of the IGF1R TKIs enhanced response compared to dual targeting strategies in three of the four HER2 positive breast cancer cell lines tested. Furthermore, in a cell line model of trastuzumab-resistant HER2 positive breast cancer (BT474/Tr), tamoxifen combined with an IGF1R TKI produced a similar enhanced response as observed in the parental BT474 cells suggesting that this combination may overcome acquired trastuzumab resistance in this model. Combining ER and IGF1R targeting with HER2 targeted therapies may be an alternative to HER2 targeted therapy and chemotherapy for patients with HER2/ER/IGF1R positive breast cancer.

Cyclic-RGDyC functionalized liposomes for dual-targeting of tumor vasculature and cancer cells in glioblastoma: An in vitro boron neutron capture therapy study.

The efficacy of boron neutron capture therapy depends on the selective delivery of 10B to the target. Integrins αvβ3 are transmembrane receptors over-expressed in both glioblastoma cells and its neovasculature. In this study, a novel approach to dual-target glioblastoma vasculature and tumor cells was investigated. Liposomes (124 nm) were conjugated with a αvβ3 ligand, cyclic arginine-glycine-aspartic acid-tyrosine-cysteine peptide (c(RGDyC)-LP) (1% molar ratio) through thiol-maleimide coupling. Expression of αvβ3 in glioblastoma cells (U87) and human umbilical vein endothelial cells (HUVEC), representing tumor angiogenesis, was determined using Western Blotting with other cells as references. The results showed that both U87 and HUVEC had stronger expression of αvβ3 than other cell types, and the degree of cellular uptake of c(RGDyC)-LP correlated with the αvβ3-expression levels of the cells. In contrast, control liposomes without c(RGDyC) showed little cellular uptake, regardless of cell type. In an in vitro boron neutron capture therapy study, the c(RGDyC)-LP containing sodium borocaptate generated more rapid and significant lethal effects to both U87 and HUVEC than the control liposomes and drug solution. Interestingly, neutron irradiated U87 and HUVEC showed different types of subsequent cell death. In conclusion, this study has demonstrated the potential of a new dual-targeting strategy using c(RGDyC)-LP to improve boron neutron capture therapy for glioblastoma.

Clinical Pharmacology and Translational Aspects of Bispecific Antibodies.

Clinical Pharmacology and Translational Aspects of Bispecific Antibodies.

Succinimide Formation from an NGR-Containing Cyclic Peptide: Computational Evidence for Catalytic Roles of Phosphate Buffer and the Arginine Side Chain.

The Asn-Gly-Arg (NGR) motif and its deamidation product isoAsp-Gly-Arg (isoDGR) have recently attracted considerable attention as tumor-targeting ligands. Because an NGR-containing peptide and the corresponding isoDGR-containing peptide target different receptors, the spontaneous NGR deamidation can be used in dual targeting strategies. It is well known that the Asn deamidation proceeds via a succinimide derivative. In the present study, we computationally investigated the mechanism of succinimide formation from a cyclic peptide, c[CH2CO-NGRC]-NH2, which has recently been shown to undergo rapid deamidation in a phosphate buffer. An H2PO4− ion was explicitly included in the calculations. We employed the density functional theory using the B3LYP functional. While geometry optimizations were performed in the gas phase, hydration Gibbs energies were calculated by the SM8 (solvation model 8) continuum model. We have found a pathway leading to the five-membered ring tetrahedral intermediate in which both the H2PO4− ion and the Arg side chain act as catalyst. This intermediate, once protonated at the NH2 group on the five-membered ring, was shown to easily undergo NH3 elimination leading to the succinimide formation. This study is the first to propose a possible catalytic role for the Arg side chain in the NGR deamidation.

The selective MEK1 inhibitor Selumetinib enhances the antitumor activity of everolimus against renal cell carcinoma in vitro and in vivo.

Renal cell carcinoma (RCC) is a urologic malignant cancer and often diagnosed at an advanced stage, which results in high mortality. Targeted therapy may improve the quality of life and survival of patients who are not suitable for nephrectomy. Everolimus, an mTOR inhibitor, is currently used as sequential or second-line therapy for RCC refractory to Sunitinib or sorafenib. However, its efficiency is palliative. In this study, we evaluated whether the antitumor activity of everolimus against RCC is enhanced by selumetinib, a selective MEK1 inhibitor. We discovered that everolimus in combination with selumetinib synergistically inhibited the proliferation of Caki-1, 786-O and 769-P cells in vitro. Mechanistically, this combination decreased p-RPS6 and p-4E-BP1 dramatically, which causes G1 cell cycle arrest and prevents reactivation of AKT and ERK. In vivo, the antitumor efficacy and pharmacodynamic biomarkers of the combination therapy were recapitulated in Caki-1 xenograft model. In addition, this combination treatment potently inhibited angiogenesis in xenograft models by impairing VEGF secretion from tumor cells. Our findings provide a sound evidence that combination of everolimus and selumetinib is a potential dual-targeted strategy for renal cell carcinoma.

A Nanosystem of Amphiphilic Oligopeptide-Drug Conjugate Actualizing Both αvβ3 Targeting and Reduction-Triggered Release for Maytansinoid.

To design a prodrug-based self-assembling nanosystem with both ligand targeting and stimuli-responsive features, and elucidate the superiority of each targeting strategy and the synergistic effect between them, we synthesized four small molecule amphiphilic peptide-drug conjugates (APDCs) using maytansinoid (DM1) as a cytotoxic agent, cRGDfK as a homing peptide, and disulfide (SS) or thioether (SMCC) as linker. Owing to their amphiphilicity, the APDCs could self-assemble into nanoparticles (APDC@NPs) which were evaluated in vitro in three different cell lines and in vivo in tumor-bearing C57BL/6 mice. The RSSD@NPs showed the strongest interaction with αvβ3 integrin, highest cell uptake and intracellular free drug level, and best antitumor efficacy in vitro and in vivo, while it shared the same goodness with other test nanosystems in terms of high drug loading, EPR effect and free of potentially toxic polymers. Especially, the in vivo efficacy of RSSD@NPs was 2 fold of free DM1 which is too cytotoxic to be a drug, while the active targeted APDC@NPs demonstrated acceptable system, tissue and blood compatibility. In αvβ3-positive cells or tumors, the RGD targeting contributed much more than disulfide in anticancer effect. The maximum synergism of the two strategies reached to 22 fold in vitro and 3 fold in vivo. Generally, the active targeting, prodrug and nanosystem could significantly decrease the toxicity of free DM1 and improve its therapy outcome via combining active targeting, prodrug and nanopreparation, especially the dual targeting strategies and their synergism.

Dual-Targeting Magnetic PLGA Nanoparticles for Codelivery of Paclitaxel and Curcumin for Brain Tumor Therapy.

Chemotherapy is one of the most important strategies for glioma treatment. However, the "impermeability" of the blood-brain barrier (BBB) impedes most chemotherapeutics from entering the brain, thereby rendering very few drugs suitable for glioma therapy, letting alone application of a combination of chemotherapeutics. Thereby, there is a pressing need to overcome the obstacles. A dual-targeting strategy was developed by a combination of magnetic guidance and transferrin receptor-binding peptide T7-mediated active targeting delivery. The T7-modified magnetic PLGA nanoparticle (NP) system was prepared with co-encapsulation of the hydrophobic magnetic nanoparticles and a combination of drugs (i.e., paclitaxel and curcumin) based on a "one-pot" process. The combined drugs yielded synergistic effects on inhibition of tumor growth via the mechanisms of apoptosis induction and cell cycle arrest, displaying significantly increased efficacy relative to the single use of each drug. Dual-targeting effects yielded a >10-fold increase in cellular uptake studies and a >5-fold enhancement in brain delivery compared to the nontargeting NPs. For the in vivo studies with an orthotopic glioma model, efficient brain accumulation was observed by using fluorescence imaging, synchrotron radiation X-ray imaging, and MRI. Furthermore, the antiglioma treatment efficacy of the delivery system was evaluated. With application of a magnetic field, this system exhibited enhanced treatment efficiency and reduced adverse effects. All mice bearing orthotopic glioma survived, compared to a 62.5% survival rate for the combination group receiving free drugs. This dual-targeting, co-delivery strategy provides a potential method for improving brain drug delivery and antiglioma treatment efficacy.