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.

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.

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.

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.

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.

pH-sensitive polymeric micelles triggered drug release for extracellular and intracellular drug targeting delivery

Most of the conventional chemotherapeutic agents used for cancer chemotherapy suffer from multidrug resistance of tumor cells and poor antitumor efficacy.Based on physiological differences between the normal tissue and the tumor tissue,one effective approach to improve the efficacy of cancer chemotherapy is to develop pH-sensitive polymeric micellar delivery systems.The copolymers with reversible protonationedeprotonation core units or acid-liable bonds between the therapeutic agents and the micelle-forming copolymers can be used to form pH-sensitive polymeric micelles for extracellular and intracellular drug smart release.These systems can be triggered to release drug in response to the slightly acidic extracellular fluids of tumor tissue after accumulation in tumor tissues via the enhanced permeability and retention effect,or they can be triggered to release drug in endosomes or lysosomes by pH-controlled micelle hydrolysis or dissociation after uptake by cells via the endocytic pathway.The pH-sensitive micelles have been proved the specific tumor cell targeting,enhanced cellular internalization,rapid drug release,and multidrug resistance reversal.The multifunctional polymeric micelles combining extracellular pH-sensitivity with receptor-mediated active targeting strategies are of great interest for enhanced tumor targeting.The micelles with receptor-mediated and intracellular pH targeting functions are internalized via receptor-mediated endocytosis followed by endosomal-pH triggered drug release inside the cells,which reverses multidrug resistance.The pH sensitivity strategy of the polymeric micelles facilitates the specific drug delivery with reduced systemic side effects and improved chemotherapeutical efficacy,and is a novel promising platform for tumor-targeting drug delivery.

Prognostic value and predictive threshold of tumor volume for patients with locally advanced nasopharyngeal carcinoma receiving intensity-modulated radiotherapy

Background: Gross target volume of primary tumor(GTV?P) is very important for the prognosis prediction of patients with nasopharyngeal carcinoma(NPC), but it is unknown whether the same is true for locally advanced NPC patients treated with intensity?modulated radiotherapy(IMRT). This study aimed to clarify the prognostic value of tumor volume for patient with locally advanced NPC receiving IMRT and to ind a suitable cut?of value of GTV?P for prognosis prediction.Methods: Clinical data of 358 patients with locally advanced NPC who received IMRT were reviewed. Receiver oper?ating characteristic(ROC) curves were used to identify the cut?of values of GTV?P for the prediction of diferent end?points [overall survival(OS), local relapse?free survival(LRFS), distant metastasis?free survival(DMFS), and disease?free survival(DFS)] and to test the prognostic value of GTV?P when compared with that of the American Joint Committee on Cancer T staging system.Results: The 358 patients with locally advanced NPC were divided into two groups by the cut?of value of GTV?P as determined using ROC curves: 219(61.2%) patients with GTV?P ≤46.4 mL and 139(38.8%) with GTV?P >46.4 mL. The 3?year OS, LRFS, DMFS, and DFS rates were all higher in patients with GTV?P ≤46.4 mL than in those with GTV?P > 46.4 mL(all P < 0.05). Multivariate analysis indicated that GTV?P >46.4 mL was an independent unfavorable prognostic factor for patient survival. The ROC curve veriied that the predictive ability of GTV?P was superior to that of T category(P < 0.001). The cut?of values of GTV?P for the prediction of OS, LRFS, DMFS, and DFS were 46.4, 57.9, 75.4 and 46.4 mL, respectively.Conclusion: In patients with locally advanced NPC, GTV?P >46.4 mL is an independent unfavorable prognostic indi?cator for survival after IMRT, with a prognostic value superior to that of T category.

Prognostic factors of primary gastrointestinal stromal tumors： a cohort study based on high-volume centers

Objective： We aimed to evaluate the clinicopathologic characteristics, immunohistochemical expression and prognostic factors of patients with primary gastrointestinal stromal tumors（GISTs）.Methods： Data from 2,570 consecutive GIST patients from four medical centers in China（January2001–December 2015） were reviewed. Survival curves were constructed by the Kaplan-Meier method, and Cox regression models were used to identify independent prognostic factors.Results： Of the included patients, 1,375（53.5%） were male, and the patient age range was 18 to 95（median, 58）years. The tumors were mostly found in the stomach（64.5%）, small intestine（25.1%） and colorectal region（5.1%）.At the time of diagnosis, the median tumor size was 4.0（range： 0.1–55.0） cm, and the median mitotic index per 50 high power fields（HPFs） was 3（range： 0–254）. Of the 2,168 resected patients, 2,009（92.7%） received curative resection. According to the modified National Institutes of Health（NIH） classification, 21.9%, 28.9%, 14.1% and35.1% were very low-, low-, intermediate-and high-risk tumors, respectively. The rate of positivity was 96.4% for c-Kit, 87.1% for CD34, 96.9% for delay of germination 1（DOG-1）, 8.0% for S-100, 31.0% for smooth muscle actin（SMA） and 5.1% for desmin. However, the prognostic value of each was limited. Multivariate analysis showed that age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors. Furthermore, we found that high-risk patients benefited significantly from postoperative imatinib（P〈0.001）, whereas intermediate-risk patients did not（P=0.954）.Conclusions： Age, tumor size, mitotic index, tumor site, occurrence of curative resection and postoperative imatinib were independent prognostic factors in patients with GISTs. Moreover, determining whether intermediate-risk patients can benefit from adjuvant imatinib would be of considerable interest in future studies.

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

Harnessing bacteria for tumor therapy:Current advances and challenges

After a century of standstill,bacteria-based tumor therapy has resurged recently benefiting from the revolution of tumor immunotherapy,which provides unique solutions to tackle the obstacles of traditional tumor treatments.Obligate and facultative anaerobes with active tropism can selectively colonize at tumor sites and suppress tumor growth via different mechanisms,serving as attractive tools for tumor treatment either as a monotherapy or combining with other therapies for synergistic anti-tumor effects.In this critical review,we introduce the recent advances of bacteria-based tumor therapy from the following aspects.First,the general properties of bacteria are reviewed emphasizing on their structural components related to tumor immunotherapy,and the main bacteria that have been used in tumor therapy are listed.Then,the benefits of bacteria for tumor therapy are illustrated,such as tumor targetability,deep penetration,and facile genetic engineering for attenuation,enhanced efficacy,as well as bioimaging.Next,anti-tumor mechanisms of bacteria are summarized,which refer to intrinsic tumoricidal activities,immune activation,bacteria metabolism,and their capability to regulate gut microbiota homeostasis.Moreover,bacteria could act as carriers to deliver various types of therapeutics to achieve combination therapy with improved efficacy.In addition,several challenges for anti-tumor applications of bacteria are discussed regarding the delivery,efficacy and safety issues,and potential solutions are also provided.Finally,the possible improvements and perspectives are discussed in the end,which provide a guideline for the design of advanced bacteria-based tumor therapeutics in the future.

Recent progress on nanoparticle-based drug delivery systems for cancer therapy

The development of cancer nanotherapeutics has attracted great interest in the recent decade. Cancer nanotherapeutics have overcome several limitations of conventional therapies, such as nonspecific biodistribution, poor water solubility, and limited bioavailability. Nanoparticles with tuned size and surface characteristics are the key components of nanotherapeutics, and are designed to passively or actively deliver anti-cancer drugs to tumor cells. We provide an overview of nanoparticle-based drug delivery methods and cancer therapies based on tumor-targeting delivery strategies that have been developed in recent years.

Effect of the structure of ginsenosides on the in vivo fate of their liposomes

To utilize themultiple functions and give full play of ginsenosides,a variety of ginsenosides with different structures were prepared into liposomes and evaluated for their effect on the stability,pharmacokinetics and tumor targeting capability of liposomes.The results showed that the position and number of glycosyl groups of ginsenosides have significant effect on the in vitro and in vivo properties of their liposomes.The pharmacokinetics of ginsenosides liposomes indicated that the C-3 sugar group of ginsenosides is beneficial to their liposomes for longer circulation in vivo.The C-3 and C-6 glycosyls can enhance the uptake of their liposomes by 4T1 cells,and the glycosyls at C-3 position can enhance the tumor active targeting ability significantly,based on the specific binding capacity to Glut 1 expressed on the surface of 4T1 cells.According to the results in the study,ginsenoside Rg3 and ginsenoside Rh2 are potential for exploiting novel liposomes because of their cholesterol substitution,long blood circulation and tumor targeting capabilities.The results provide a theoretical basis for further development of ginsenoside based liposome delivery systems.

A novel tumor-targeting treatment strategy uses energy restriction via co-delivery of albendazole and nanosilver

Although nanotechnology has been rapidly developed and applied in tumor targeting, the outcome of chemotherapy remains greatly restricted by the toxicity of cytotoxic drugs in normal tissues and cells. Therefore, the development of alternative delivery systems, with few side effects in normal cells, has attracted increasing attention. Energy restriction is a novel and promising approach to cancer treatment, which can restrict tumor growth via inhibition of cellular energy metabolism. In this study, a novel tumor targeting system, based on folate-conjugated bovine serum albumin （BSA）, was developed to co-deliver albendazole and nanosilver simultaneously, to restrain the energy metabolism of tumor cells. This nanosystem showed stronger anti-tumor efficacy than those using nanoparticles without folic acid modification, nanosilver, or albendazole, both in vitro and in vivo. This nanosystem depleted cellular ATP via direct inhibition of glycolytic enzymes and mitochondrial damage, resulting in inhibition of proliferation, cell-cycle arrest, and apoptosis of tumor cells. The enhanced anti-tumor activity contributed to the tumor-targeting ability of this system, resulting in specific energy inhibition in tumor cells. Toxicity evaluation was performed to confirm the safety of this system. This nanosystem provides an efficient and safe strate~ for tumor therapy.

Targeting neuropilin-1 interactions is a promising anti-tumor strategy

Neuropilins(NRP1 and NRP2)are multifunctional receptor proteins that are involved in nerve,blood vessel,and tumor development.NRP1 was first found to be expressed in neurons,but subsequent studies have demonstrated its surface expression in cells from the endothelium and lymph nodes.NRP1 has been demonstrated to be involved in the occurrence and development of a variety of cancers.NRP1 interacts with various cytokines,such as vascular endothelial growth factor family and its receptor and transforming growth factor p i and its receptor,to affect tumor angiogenesis,tumor proliferation,and migration.In addition,NRP1+regulatory T cells(Tregs)play an inhibitory role in tumor immunity.High numbers of NRP1+Tregs were associated with cancer prognosis.Targeting NRP1 has shown promise,and antagonists against NRP1 have had therapeutic efficacy in preliminary clinical studies.NRP1 treatment modalities using nanomaterials,targeted drugs,oncolytic viruses,and radio-chemotherapy have gradually been developed.Hence,we reviewed the use of NRP1 in the context of tumorigenesis,progression,and treatment.

Selection of DNA aptamer that specific binding human carcinoembryonic antigen in vitro

Objective：To select the specific aptamer of carcinoembryonic antigen （CEA）, one of the most attractive molecule for cancer target therapy and imaging. Methods： Seven rounds in vitro selection were performed against the purified CEA protein. Ligand-mediated target purification and Co-immunoprecipitation were adopted to verify the specific binding of the aptamer to the purified and native protein separately. Results：The CEA-specific aptamer which can bind both the purified and native protein with the high specificity was obtained. Conclusion：This is the first time the CEA specific apatmer was produced. The results in this study provides the preliminary evidence for further investigation and application of CEA-aptamer in the future.

Preparation and functional study of pH-sensitive amorphous calcium phosphate nanocarriers

Recently,multifunctional nanoparticles have shown great prospects in cancer treatment,which have the ability to simultaneously deliver the drug,image and target tumor cells.In this paper,we designed a luminescent nanoparticles platform based on hydrothermal hyaluronic acid/amorphous calcium phosphate(HA-FCNs/ACP)with multifunctional properties for drug delivery,bio-imaging,and targeting treatment.HA-FCNs/ACP shows an ability to load curcumin(Cur)with pH-sensitive responsive drug release behavior and excellent biocompatibility.HA-FCNs/ACP dispersed in the cytoplasm through the overexpressed CD44 receptor that is actively targeted into human lung cancer cells(A549 cells).Meanwhile,the viability of A549 cells was significantly inhibited in vitro.The prepared HA-FCNs and HA-FCNs/ACP both exhibit excellent targeted bioimaging performance on cancer cells.Hence,the as-prepared nanoparticles have promising applications in treating tumor disease.

CXCR4 Peptide Conjugated Au-Fe2O3 Nanoparticles for Tumor-targeting Magnetic Resonance Imaging

Peptide-functionalized Au-Fe2O3 nanoparticles（termed as anti-CXCR4-Au-Fe2O3 NPs） have been constructed through conjugation of dumbbell-like Au-Fe203 NPs with C-X-C motif chemokine receptor 4（CXCR4） binding cyclic peptide. One dumbbelMike Au-Fe2O3NP composes an Au NP[（3.3±0.3） nm in diameter] for conjugating CXCR4 binding cyclic peptide through Au-S covalent bond and a Fe2O3 NP[（8.7±0.8） nm in diameter] for using as T2-weighted magnetic resonance imaging（MRI） contrast agent. The anti-CXCR4-Au-Fe2O3 NPs have reasonable biocompatibility and integration of T2-weighted MRI contrast and tumor-targeting functionalities. The anti- CXCR4-Au-Fe2O3 NPs exhibit strong interactions with two kinds of breast tumor cells, MCF-7 cells and MDA-MB-231 cells, and high negative contrast in MRI of MDA-MB-231 tumor bearing mouse with 62% decreasing of MRI signal, indicating that the anti-CXCR4-Au-Fe2O3 NPs can recognize tumor with high efficacy and specificity.

Enhanced lysosome escape mediated by 1,2-dicarboxylic-cyclohexene anhydride-modified poly-L-lysine dendrimer as a gene delivery system

Antisense oligodeoxynucleotide(ASODN)can directly interfere a series of biological events of the target RNA derived from tumor cells through Watson-Crick base pairing,in turn,plays antitumor therapeutic roles.In the study,a novel HIF-1αASODN-loaded nanocomposite was formulated to efficiently deliver gene to the target RNA.The physicochemical properties of nanocomposite were characterized using TEM,FTIR,DLS and zeta potentials.The mean diameter of resulting GEL-DGL-FA-ASODN-DCA nanocomposite was about 170–192 nm,and according to the agarose gel retardation assay,the loading amount of ASODN accounted for 166.7 mg/g.The results of cellular uptake showed that the nanocomposite could specifically target to HepG2 and Hela cells.The cytotoxicity assay demonstrated that the toxicity of vectors was greatly reduced by using DCA to reversibly block the cationic DGL.The subcellular distribution images clearly displayed the lysosomal escape ability of the DCA-modified nanocomposite.In vitro exploration of molecular mechanism indicated that the nanocomposite could inhibit m RNA expression and HIF-1αprotein translation at different levels.In vivo optical images and quantitative assay testified that the formulation accumulated preferentially in the tumor tissue.In vivo antitumor efficacy research confirmed that this nanocomposite had significant antitumor activity and the tumor inhibitory rate was 77.99%.These results manifested that the GEL-DGL-FA-ASODNDCA nanocomposite was promising in gene therapeutics for antitumor by interacting directly with target RNA.

Current strategies for improving limitations of proteolysis targeting chimeras

Proteolysis targeting chimeras(PROTACs)are bifunctional degrader molecules via hijacking the ubiquitinproteasome system(UPS)to specifically eliminate targeted proteins.PROTACs have gained momentum as a new modality of attractive technologies in the drug discovery landscape,since it allows to degrade disease-related proteins effectively.Although some PROTACs drugs reached the clinical research,they are still facing some bottlenecks and challenges that should not be neglected,such as poor oral bioavailability and potential toxic side effects.To overcome these limitations,herein,we provide an overview of recent strategies for improving the durability of PROTACs by enhancing cell permeability and reducing toxic side effects.Meanwhile,the impact of these strategies on improving oral bioavailability as well as their advantages and drawbacks will also be discussed.This review will give a useful reference toolbox for PROTACs design and further promote its clinical application.

Interleukin-6: a villain in the drama of pancreatic cancer development and progression

BACKGROUND： Pancreatic ductal adenocarcinoma（PDAC）is a devastating malignancy with a poor prognosis and little treatment options. The development and progression of the disease is fostered by inflammatory cells and cytokines. One of these cytokines is interleukin-6（IL-6）, which plays an important role in a wide range of biologic activities.DATA SOURCES： A systematic search of PubMed was performed to identify relevant studies using key words such as interleukin-6,inflammatory cytokines, inflammation and pancreatic cancer or PDAC. Articles related to IL-6 and pancreatic cancer were systematically reviewed.RESULTS： IL-6 is elevated in the serum of pancreatic cancer patients and correlates with cachexia, advanced tumor stage and poor survival. Its expression is enhanced by hypoxia and proteins involved in pancreatic cancer development like Kras,mesothelin or ZIP4. IL-6 in turn contributes to the generation of a pro-tumorigenic microenvironment and is probably involved in angiogenesis and metastasis. In experimental mouse models of PDAC, IL-6 was important for the development and progression of precursor lesions.CONCLUSION： IL-6 emerges as a key player in pancreatic cancer development and progression, and hence should be considered as a new therapeutic target.