One Stone Four Birds:A Novel Liposomal Delivery System Multi-functionalized with Ginsenoside Rh2 for Tumor Targeting Therapy

Liposomes hold great potential in anti-cancer drug delivery and the targeting treatment of tumors.However,the clinical therapeutic efficacy of liposomes is still limited by the complexity of tumor microenvironment(TME)and the insufficient accumulation in tumor sites.Meanwhile,the application of cholesterol and polyethylene glycol(PEG),which are usually used to prolong the blood circulation and stabilize the structure of liposomes respectively,has been questioned due to various disadvantages.Herein,we developed a ginsenoside Rh2-based multifunctional liposome system(Rh2-lipo)to effectively address these challenges once for all.Different with the conventional’wooden’liposomes,Rh2-lipo is a much more brilliant carrier with multiple functions.In Rh2-lipo,both cholesterol and PEG were substituted by Rh2,which works as membrane stabilizer,long-circulating stealther,active targeting ligand,and chemotherapy adjuvant at the same time.Firstly,Rh2 could keep the stability of liposomes and avoid the shortcomings caused by cholesterol.Secondly,Rh2-lipo showed a specifically prolonged circulation behavior in the blood.Thirdly,the accumulation of the liposomes in the tumor was significantly enhanced by the interaction of glucose transporter of tumor cells with Rh2.Fourth,Rh2-lipo could remodel the structure and reverse the immunosuppressive environment in TME.When tested in a 4T1 breast carcinoma xenograft model,the paclitaxel-loaded Rh2-lipo realized high efficient tumor growth suppression.Therefore,Rh2-lipo not only innovatively challenges the position of cholesterol as a liposome component,but also provides another innovative potential system with multiple functions for anti-cancer drug delivery.

5-Fluorocytosine–Sugar Conjugates for Glucose Transporter-Mediated Tumor Targeting: Synthesis, Cytotoxicity, and Cellular Uptake Mechanism

Two novel sugar-conjugated 5-fluorocytosine(5-FC)antineoplastic compounds were designed and synthesized to improve the selective drug uptake by targeting the tumor-specific glucose transporter(GLUT).The antitumor activity of these compounds was evaluated in four different human cancer cell lines:A549(human lung cancer cell line),HT29(human colorectal cancer cell line),H460(human lung cancer cell line),and PC3(human prostate cancer cell line).The sugar conjugates exhibited cytotoxicity similar to or higher than 5-FC and 1-hexylcarbamoyl-5-FC in A549,HT29,H460,and PC3.Furthermore,GLUT-mediated transport of the glycoconjugate was investigated with GLUT inhibitor-mediated cytotoxicity analysis in a GLUT-overexpressing HT29 cell line.The cell-killing potency of 5-FC glycoconjugate was found to depend significantly on the GLUT inhibitor,and the cellular uptake of molecules was regulated by GLUT-mediated transport.All the results demonstrate the potential advantages of glycoconjugation for Warburg effect-targeted drug design.

Tumor targeting of ^(125)I-labeled anti-EGFR monoclonal antibody LA22 in HT-29 human colon cancer

Epidermal growth factor receptor (EGFR) plays a critical role in proliferation, apoptosis, angiogenesis, invasiveness and distant metastasis of tumors. In this study, the tumor targeting properties of anti-EGFR monoclonal antibody (mAb) LA22 in a colon cancer mouse model are evaluated. The results from flow cytometry assay and immunofluorescent staining clearly showed that HT-29 human colon cancer cells were EGFR positive, and the binding of mAb LA22 to the HT-29 cell surface was specific. The saturation binding experiment of 125I-LA22 to HT-29 cells revealed that LA22 possessed moderate affinity to EGFR with the Kd value calculated to be 3.28±0.76 nM. The in vivo γ imaging demonstrated the specific accumulation of 125I-LA22 in HT-29 tumor xenografts. The specific tumor targeting properties of mAb LA22 make it a good candidate for tumor targeted radioimmunotherapy of EGFR-positive tumors when it is labeled with therapeutic nuclides, such as 131I, 177Lu, or 90Y.

Folic Acid-Polyethyleneimine-Ethosome as a Potential Tumor Targeting Carrier: Preparation, Characterization and in vitro Evaluation

A novel composite carrier of folic acid(FA)-polyethyleneimine(PEI)-ethosome(Eth)(FA-PEI-Eth)was developed for the treatment of cancers through loading and targeting delivery of multidrug(including gene and other drugs)into cancer cells.Physical and chemical property tests were done to prove the grafting of the composite.Gel retardation test was done to determine the optimal ratio of DNA@PEI complex,and cytocompatibility tests and tumor cell uptake tests were done to evaluate the efficiency of the composite.The results demonstrated that the FA-PEI-Eth could effectively deliver a gene and other drugs into tumor cells simultaneously,and suggested that this composite would be a promising carrier in tumor-targeted therapy applications.

A detachable coating of cholesterol-anchored PEG improves tumor targeting of cell-penetrating peptide-modified liposomes

Cell-penetrating peptides(CPPs)have been widely used to enhance the membrane transloca-tion of various carriers for many years,but the non-specificity of CPPs seriously limits their utility in vivo.In this study,cholesterol-anchored,reduction-sensitive PEG(first synthesized by our laboratory)was applied to develop a co-modified liposome with improved tumor targeting.Following optimization of the formulation,the in vitro and in vivo properties of the co-modified liposome were evaluated.The co-modified liposome had a much lower cellular uptake and tumor spheroid uptake,but a much higher tumor accumulation compared to CPP-modified liposome,indicating the non-specific penetration of CPPs could be attenuated by the outer PEG coating.With the addition of exogenous reducing agent,both the in vitro and in vivo cellular uptake was markedly increased,demonstrating that the reduction-sensitive PEG coating achieved a controllable detachment from the surface of liposomes and did not affect the penetrating abilities of CPPs.The present results demonstrate that the combination of cholestervsitive PEG and CPPs is an ideal alternative for the application of CPP-modified carriers in vivo.

Perspectives on bone-targeted nano-drug carriers for bone tumor treatment

Bone tumour is one of most common primary cancer which exhibits cancerous osteoblastic differentiation and malignant osteoid in patients.At present,chemotherapy(pre-and post-operative)is used as a standard treatment protocol for bone tumour.However,drugs used in the treatment of bone tumour induce high toxicity to normal tissues including anaemia,neutropenia,thrombocytopenia,and heart damage which further reduce the survival rate of patients.Therefore,there is an urgent need to develop a new therapeutic approach for the treatment such that it induce maximum cell killing effect in tumor cells while sparing the healthy bone cells.In this article,some new perspectives were provided on the development of bone-targeted nano-drug carriers for bone cancer treatment.We hope such discussions wouldencourage more detailed and careful studies to support product development of bone-targeted drug carriers for bone cancer treatment.

Preparation and functional characterization of tumor-targeted folic acid-chitosan conjugated nanoparticles loaded with mitoxantrone

Folic acid conjugated chitosan was prepared by cross-linking reaction with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride(EDC), and then used as a template to prepare folic acid-chitosan(FA-CS) conjugated nanoparticles and load mitoxantrone nanoparticles(FA-CSNP/MTX). Drug dissolution testing, CCK-8 method, and confocal microscopy were used to detect their controlled-release capability in different situations and the specific uptake by HONE1 cells. The experimental results show that the nanoparticles have uniform size distribution of 48-58 nm. The highest encapsulation rate of the particles on mitoxantrone hydrochloride(MTX) is(77.5±1.9)%, and the drug loading efficiency is(18.4±0.4)%. The sustained release effect, cell growth inhibition activity and targeting effect of the FA-CS/MTX nanoparticles are good in artificial gastric fluid and intestinal fluid. It is demonstrated that the FA-CSNP system is a potentially useful system for the targeted delivery of anticancer drug MTX.

Tumor targeting of HPMA copolymer conjugates containing sulfadiazine groups

To develop new tumor targeting macromolecular conjugates,poly（HPMA）-SD-APMA-DTPA（HPMA：N-（2-hydroxypropyl）- methacrylamide;APMA：N-（3-ammopropyl）methacrylamide;DTPA：diethylenetriaminepentaacetic acid;SD：sulfadiazine） was synthesized and characterized.The poly（HPMA）-SD-DTPA conjugates were radiolabeled with the radionuclide ^（99m）Tc and tested for uptake by cultured H22 cells in vitro.DTPA-^（99m）Tc（radiotracer 1） and poly（HPMA）-DTPA-^（99m）Tc（radiotracer 2） were also synthesized and characterized for comparison.The uptake of poly（HPMA）-SD-DTPA-^（99m）Tc（radiotracer 3,34.76%） was significantly higher than that of poly（HPMA）-DTPA-^（99m）Tc（16.40%）,indicating that uptake of the poly（HPMA）-SD-DTPA-^（99m）T was active binding.The uptake of poly（HPMA）-DTPA-^（99m）Tc was significantly higher than that of DTPA-^（99m）Tc（2.98%）, suggesting that uptake of the poly（HPMA）-DTPA-^（99m）T was passive binding.The data suggest that the poly（HPMA）-SDAPMA -DTPA conjugates might be useful as tumor targeting macromolecular conjugates.

Construction of Magnetic Resonance Imaging Visible Polymeric Vector for Efficient Tumor Targeted siRNA Delivery

RNA interference(RNAi),known for the highly efficient targeted gene silencing,has been demonstrated to be a promising means for cancer treatment.Meanwhile,an effective approach for siRNA delivery is urgently needed to meet the needs for its clinical application.Herein,we constructed a polymeric vector labeled with superparamagnetic iron oxide(SPIO)for magnetic resonance imaging(MRI)visible siRNA delivery.EGFR antibody was also modified to the surface of nanodrug to enhance the delivery effect.Our results showed that the vector exhibited great siRNA complexation ability and mediated an increased endocytosis of siRNA without obvious cytotoxicity.Besides,both in vitro and in vivo studies evidenced the vector could effectively deliver siRNA into tumor cells,exert highly interfering effect,and show potent MR imaging capacity.The study provides a promising MRI-visible and EGFR targeting delivery system to improve RNAi efficacy for cancer therapy.

Molecular regulation of vasculogenic mimicry in tumors and potential tumor-target therapy

"Vasculogenic mimicry(VM)",is a term that describes the unique ability of highly aggressive tumor cells to express a multipotent,stem cell-like phenotype,and form a pattern of vasculogenic-like networks in threedimensional culture.As an angiogenesis-independent pathway,VM and/or periodic acid-schiff-positive patterns are associated with poor prognosis in tumor patients.Moreover,VM is resistant to angiogenesis inhibitors.Here,we will review the advances in research on biochemical and molecular signaling pathways of VM in tumors and on potential anti-VM therapy strategy.

Development and application of hyaluronic acid in tumor targeting drug delivery

Hyaluronic acid(HA)is a natural polysaccharide that has gained much attention due to its biocompatibility,enzyme degradation capacity and active tumor targeting capacity.Its receptor,CD44,is overexpressed in many kinds of cancers and is associated with tumor progress,infiltration and metastasis.Therefore,many researchers have developed various HA-based drug delivery systems for CD44-mediated tumor targeting.In this review,we systemically overview the basic theory of HA,its receptor and hyaluronidase,then we categorize the studies in HA-based drug delivery systems according to the functions of HA,including tumor-targeting materials,enzyme-sensitive biodegradable modality,pHsensitive component,reduction-sensitive component,and the gel backbone.Finally,the perspective is discussed.

Genetic alteration and mutation profiling of circulating cell-free tumor DNA(cfDNA) for diagnosis and targeted therapy of gastrointestinal stromal tumors

Gastrointestinal stromal tumors(GISTs) have been recognized as a biologically distinctive type of tumor,different from smooth muscle and neural tumors of the gastrointestinal tract.The identification of genetic aberrations in proto-oncogenes that drive the growth of GISTs is critical for improving the efficacy of cancer therapy by matching targeted drugs to specific mutations.Research into the oncogenic mechanisms of GISTs has found that these tumors frequently contain activating gene mutations in either platelet-derived growth factor receptor A(PDGFRA) or a receptor tyrosine protein associated with a mast cell growth factor receptor encoded by the KIT gene.Mutant cancer subpopulations have the potential to disrupt durable patient responses to molecularly targeted therapy for GISTs,yet the prevalence and size of subpopulations remain largely unexplored.Detection of the cancer subpopulations that harbor low-frequency mutant alleles of target proto-oncogenes through the use of molecular genetic methods,such as polymerase chain reaction(PCR) target amplification technology,is hampered by the high abundance of wildtype alleles,which limit the sensitivity of detection of these minor mutant alleles.This is especially true in the case of mutant tumor DNA derived "driver" and "drug-resistant" alleles that are present in the circulating cell-free tumor DNA(cfDNA) in the peripheral blood circulation of GIST patients.So-called "liquid biopsy" allows for the dynamic monitoring of the patients' tumor status during treatment using minimally invasive sampling.New methodologies,such as a technology that employs a xenonucleic acid(XNA) clamping probe to block the PCR amplification of wild-type templates,have allowed improved molecular detection of these low-frequency alleles both in tissue biopsy samples and in cfDNA.These new methodologies could be widely applied for minimally invasive molecular testing in the therapeutic management of GISTs.

Screening tumor-targeting bacteriophage particles by pre-clearing phage display

Phage display technique provides a powerful approach for the discovery of new tumor-specific peptides.However,the peptides isolated through this technique usually did not possess high tumor-specific property.A pre-clearing step was introduced to increase the efficiency of biopanning by removal of particles that could interact with ubiquitously expressed cellular receptors in the non-target organs.The randomized Ph.D-CX7C phage library (Phage III) was first pre-cleared in normal mice to reduce vasculatureor organ-targeting phages to get the pre-cleared phage library,and then the tumor-targeting bacteriophage particles (Phage I) were screened from pre-clearing phage library in S180 tumor-bearing mice.The biodistribution results of 99mTc-labeled phages in mice bearing S180 tumor show that the uptake of 99mTc-labeled Phage I in tumor is high but low in normal organs,and the tumor-to-liver and tumor-to-spleen ratios of 99mTc-labeled Phage I are higher than those of 99mTc-labeled Phage II (tumor-specific phages screened from the original CX7C library) and Phage III (unscreened phages from the original CX7C library).It indicates that the yield of tumor-targeting bacteriophage particles could be improved and the non-specific binding in organs becomes weak.Consequently,the pre-clearing phage display method could improve the yield of positive hits by reducing the non-target organ accumulation of bacteriophage particles.

Therapeutic strategies for targeting the ovarian tumor stroma

Epithelial ovarian cancer is the most lethal type of gynecologic malignancy. Sixty percent of women who are diagnosed with ovarian cancer present with advancedstage disease that involves the peritoneal cavity and these patients have a 5-year survival rate of less than 30%. For more than two decades, tumor-debulking surgery followed by platinum-taxane combination chemotherapy has remained the conventional first-line treatment of ovarian cancer. Although the initial response rate is 70%-80%, most patients with advancedstage ovarian cancer eventually relapse and succumb to recurrent chemoresistant disease. A number of molecular aberrations that drive tumor progression have been identified in ovarian cancer cells and intensive efforts have focused on developing therapeutic agents that target these aberrations. However, increasing evidence indicates that reciprocal interactions between tumor cells and various types of stromal cells also play important roles in driving ovarian tumor progression and that these stromal cells represent attractive therapeutic targets. Unlike tumor cells, stromal cells within the tumor microenvironment are in general geneticallystable and are therefore less likely to become resistant to therapy. This concise review discusses the biological significance of the cross-talk between ovarian cancer cells and three major types of stromal cells(endothelial cells, fibroblasts, macrophages) and the development of new-generation therapies that target the ovarian tumor microenvironment.

Discovering metabolic vulnerability using spatially resolved metabolomics for antitumor small molecule-drug conjugates development as a precise cancer therapy strategy

Against tumor-dependent metabolic vulnerability is an attractive strategy for tumor-targeted therapy.However,metabolic inhibitors are limited by the drug resistance of cancerous cells due to their metabolic plasticity and heterogeneity.Herein,choline metabolism was discovered by spatially resolved metabolomics analysis as metabolic vulnerability which is highly active in different cancer types,and a choline-modified strategy for small molecule-drug conjugates(SMDCs)design was developed to fool tumor cells into indiscriminately taking in choline-modified chemotherapy drugs for targeted cancer therapy,instead of directly inhibiting choline metabolism.As a proof-of-concept,choline-modified SMDCs were designed,screened,and investigated for their druggability in vitro and in vivo.This strategy improved tumor targeting,preserved tumor inhibition and reduced toxicity of paclitaxel,through targeted drug delivery to tumor by highly expressed choline transporters,and site-specific release by carboxylesterase.This study expands the strategy of targeting metabolic vulnerability and provides new ideas of developing SMDCs for precise cancer therapy.

抗肿瘤分子靶向药物致化疗相关性腹泻的研究进展

化疗相关性腹泻(CRD)可导致治疗效果和患者依从性降低,影响肿瘤患者的长期治疗结局,甚至危及生命。除传统化疗药物外,许多分子靶向药物也可导致CRD,包括小分子表皮生长因子受体(EGFR)抑制剂、抗EGFR单克隆抗体、磷酸肌醇3-激酶抑制剂、血管内皮细胞生长因子受体小分子抑制剂、BCR-ABL1和KIT抑制剂、人表皮生长因子受体2靶点抑制剂、周期蛋白依赖性激酶抑制剂、抗体-药物偶联物等多种分子靶向药物。其发生机制可能与分子靶向治疗药物引起肠黏膜损伤或肠炎等有关,临床表现为大便频率增加和/或松散不成形,患者常伴有产气过多和/或肠绞痛。不同药物引起的CRD发生率不同,临床应重视病史采集和鉴别诊断,积极干预并进行动态评估,加强患者教育,以及时发现和预防肠毒性的发生。

Molecular neuro-oncology and development of targeted therapeutic strategies for brain tumors

Brain tumors are a diverse group of malignancies that remain refractory to conventional treatment approaches.Molecular neuro-oncologyhas now begun to clarify the transformed phenotype of brain tumors and identify oncogenic pathways that might be amenable to targetedtherapy.Activity of the phosphoinositide 3;kinase(PI3K)/Akt pathway is often upregulated in brain tumors due to excessive stimu-lation by growth factor receptors and Ras.Loss of function of the tumor suppressor gene PTEN also frequently contributesto

Exosomes derived from tumor adjacent fibroblasts efficiently target pancreatic tumors

The application of extracellular vesicles,particularly exosomes(EXs),is rapidly expanding in the field of medicine,owing to their remarkable properties as natural carriers of biological cargo.This study investigates utilization of exosomes derived from stromal cells of tumor adjacent normal tissues(NAF-EXs)for personalized medicine,which can be derived at the time of diagnosis by endoscopic ultrasound.Herein,we show that exosomes(EXs)derived from NAFs demonstrate differential bio-physical characteristics,efficient cellular internalization,drug loading efficiency,pancreatic tumor targeting and delivery of payloads.NAF-derived EXs(NAF-EXs)were used for loading ormeloxifene(ORM),a potent anti-cancer and desmoplasia inhibitor as a model drug.We found that ORM maintains normal fibroblast cell phenotype and renders them incompatible to be triggered for a CAF-like phenotype,which may be due to regulation of Ca^(2+) influx in fibroblast cells.NAF-EXs-ORM effectively blocked oncogenic signaling pathways involved in desmoplasia and epithelial mesenchymal transition(EMT)and repressed tumor growth in xenograft mouse model.In conclusion,our data suggests preferential tropism of NAF-EXs for PDAC tumors,thus imply feasibility of developing a novel personalized medicine for PDAC patients using autologous NAF-EXs for improved therapeutic outcome of anti-cancer drugs.Additionally,it provides the opportunity of utilizing this biological scaffold for effective therapeutics in combination with standard therapeutic regimen.

Transferrin receptor-targeted immunostimulant for photodynamic immunotherapy against metastatic tumors through b-catenin/CREB interruption

The immunosuppressive phenotype of tumor cells extensively attenuates the immune activation effects of traditional treatments.In this work,a transferrin receptor(TfR)targeted immunostimulant(PTI)is fabricated for photodynamic immunotherapy against metastatic tumors by interrupting b-catenin signal pathway.To synthesize PTI,the photosensitizer conjugated TfR targeting peptide moiety(Palmitic-K(PpIX)-HAIYPRH)is unitized to encapsulate the transcription interrupter of ICG-001.On the one hand,the recognition of PTI and TfR can promote drug delivery into tumor cells to destruct primary tumors through photodynamic therapy and initiate an immunogenic cell death with the release of tumorassociated antigens.On the other hand,PTI will interrupt the binding between b-catenin andcAMP response element-binding protein(CREB),regulating the gene transcription to downregulate programmed death ligand 1(PD-L1)while upregulating CeC motif chemokine ligand 4(CCL4).Furthermore,the elevated CCL4 can recruit the dendritic cells to present tumor-specific antigens and promote T cells activation and infiltration,and the downregulated PD-L1 can avoid the immune evasion of tumor cells and activate systemic anti-tumor immunity to eradicate lung metastasis.This work may inspire the development of antibody antibody-free strategy to activate systemic immune response in consideration of immunosuppressive conditions.