Antiangiogenesis-Combined Photothermal Therapy in the Second Near-Infrared Window at Laser Powers Below the Skin Tolerance Threshold

Photothermal agents with strong light absorption in the second near-infrared(NIR-II)region(1000-1350 nm)are strongly desired for successful photothermal therapy(PTT).In this work,titania-coated Au nanobipyramids(NBP@TiO2)with a strong plasmon resonance in the NIR-II window were synthesized.The NBP@TiO2 nanostructures have a high photothermal conversion efficiency of(93.3±5.2)%under 1064-nm laser irradiation.They are also capable for loading an anticancer drug combretastatin A-4 phosphate(CA4P).In vitro PTT studies reveal that 1064-nm laser irradiation can efficiently ablate human lung cancer A549 cells and enhance the anticancer effect of CA4P.Moreover,the CA4P-loaded NBP@TiO2 nanostructures combined with PTT induce a synergistic antiangiogenesis effect.In vivo studies show that such CA4Ploaded NBP@TiO2 nanostructures under mild 1064-nm laser irradiation at an optical power density of 0.4 W cm?2,which is lower than the skin tolerance threshold value,exhibit a superior antitumor effect.This work presents not only the development of the NBP@TiO2 nanostructures as a novel photothermal agent responsive in the NIR-II window but also a unique combined chemo-photothermal therapy strategy for cancer therapy.

Adjuvant heparanase inhibitor PI-88 therapy for hepatocellular carcinoma recurrence

AIM: To demonstrate that administering heparanase inhibitor PI-88 at 160 mg/d is safe and promising in reducing hepatocellular carcinoma(HCC) recurrence for up to 3 year following curative resection. METHODS: A total of 143 patients(83.1% of the 172 participants in the phase Ⅱ study) participated in the follow-up study. Of these patients, 50 had received no treatment, 48 had received 160 mg/d PI-88, and 45 had received 250 mg/d PI-88 during the phase Ⅱ trial. Safety parameters and the following efficacy endpoints were investigated:(1) time to recurrence;(2) diseasefree survival; and(3) overall survival. RESULTS: PI-88 at 160 mg/d delayed the onset and frequency of HCC recurrence, and provided a clinically significant survival advantage for up to 3 years after treatment compared with those of the control group:(1) the recurrence-free rate increased from 50% to 63%, and(2) time to recurrence at the 36 th percentile was postponed by 78%. The efficacy of administering PI-88 at 250 mg/d was confounded by a high dropout rate(11 out of 54 patients). Additionally, subgroup analyses of patients with(1) multiple tumors or a single tumor ≥ 2 cm; and(2) hepatitis B or C revealed that administering PI-88 at 160 mg/d conferred the most significant survival advantage(56.8% improvement in disease-free survival, P = 0.045) for patients with both risk factors for recurrence. CONCLUSION: Administering PI-88 at 160 mg/d is a safe and well-tolerated dosage that may confer significant clinical benefits for patients with HCC.

Optimal combination of antiangiogenic therapy for hepatocellular carcinoma

The success of sorafenib in prolonging survival of patients with hepatocellular carcinoma(HCC) makes therapeutic inhibition of angiogenesis a component of treatment for HCC. To enhance therapeutic efficacy, overcomedrug resistance and reduce toxicity, combination of antiangiogenic agents with chemotherapy, radiotherapy or other targeted agents were evaluated. Nevertheless, the use of antiangiogenic therapy remains suboptimal regarding dosage, schedule and duration of therapy. The issue is further complicated by combination antiangiogenesis to other cytotoxic or biologic agents. There is no way to determine which patients are most likely respond to a given form of antiangiogenic therapy. Activation of alternative pathways associated with disease progression in patients undergoing antiangiogenic therapy has also been recognized. There is increasing importance in identifying, validating and standardizing potential response biomarkers for antiangiogenesis therapy for HCC patients. In this review, biomarkers for antiangiogenesis therapy including systemic, circulating, tissue and imaging ones are summarized. The strength and deficit of circulating and imaging biomarkers were further demonstrated by a series of studies in HCC patients receiving radiotherapy with or without thalidomide.

Experimental study of gene therapy with angiostatin gene in pancreatic cancer

Objective: To study the effects of angiostatin (AS) gene mediated by liposome on human pancreatic cancer cell line SW1990. Methods: Angiostatin gene was cloned into the eu- karyotic expression vector pRC/CMV. The recombi- nant of pRC/CMV-AS was introduced into the pan- creatic cancer cell line, SW1990. The mechanism of anti-tumor was studied and tested. Results: The eukaryotic expression vector pRC/ CMV-AS was identified by the restriction digest. pRC/CMV-AS was stably integrated into the target cells and expressed by Western blot and drug-sensi- tivity tests, and inhibited the vascular endothelial cells proliferation in vitro. In addition, the effects of the angiostatin vector on reducing the volume of tumors implanted in nude mouse models were also noted. Conclusion: This study demonstrated that the recom- binant pRC/CMV-AS mediated by liposome may play a potential role in the treatment of pancreatic cancer in the future.

The functions and applications of A7R in anti-angiogenic therapy, imaging and drug delivery systems

Vascular endothelial growth factor receptor 2(VEGFR-2)and neuropilin-1(NRP-1)are two prominent antiangiogenic targets.They are highly expressed on vascular endothelial cells and some tumor cells.Therefore,targeting VEGFR-2 and NRP-1 may be a potential antiangiogenic and antitumor strategy.A7R,a peptide with sequence of Ala-Thr-Trp-Leu-Pro-Pro-Arg that was found by phage display of peptide libraries,can preferentially target VEGFR-2 and NRP-1 and destroy the binding between vascular endothelial growth factor 165(VEGF165)and VEGFR-2 or NRP-1.This peptide is a new potent inhibitor of tumor angiogenesis and a targeting ligand for cancer therapy.This review describes the discovery,function and mechanism of the action of A7R,and further introduces the applications of A7R in antitumor angiogenic treatments,tumor angiogenesis imaging and targeted drug delivery systems.In this review,strategies to deliver different drugs by A7R-modified liposomes and nanoparticles are highlighted.A7R,a new dual targeting ligand of VEGFR-2 and NRP-1,is expected to have efficient therapeutic or targeting roles in tumor drug delivery.

First line anlotinib plus liposomal doxorubicin for locally advanced or metastatic soft tissue sarcoma:A prospective,single-arm trial

Objective:To examine the efficacy and safety of anlotinib as first-line therapy to treat locally advanced or metastatic soft-tissue sarcoma.Methods:This is a single-arm trial.Treatment-naïve patients(≥14 years)with locally advanced or metastatic soft tissue sarcoma were eligible.Each treatment cycle lasted for 3 weeks,and included liposomal doxorubicin(40-50 mg/m^(2))on day 1 and anlotinib(12 mg)on days 8-21.Starting from the 9th cycle,treatment consisted of only anlotinib.Treatment continued until disease progression or intolerable toxicities.The primary efficacy end point was progression-free survival(PFS).Results:Eight patients were enrolled between July 25,2019 and January 8,2020.The median number of treatment cycles was 5.5.Within 5.9 months median follow-up,PFS events occurred in 4(4/8,50%)patients.The median PFS was 11.3 months and the 6-month PFS rate was 56%.No patients attained complete response and 2 patients(fibrosarcoma,1 patient and undifferentiated pleomorphic sarcoma,1 patient)achieved partial response.Three patients(fibrosarcoma,2 patients and synovial sarcoma,1 patient)had stable disease.The objective response rate was 25%(2/8)for the study population,and the disease control rate was 75%(6/8).No new safety concerns emerged.Conclusions:Anlotinib plus liposomal doxorubicin demonstrated antitumor activities in previously untreated locally advanced or metastatic soft tissue sarcomas.Due to the small sample size,further investigations with a larger population should be undertaken to confirm the study findings.

The relationship between treatment-induced hypertension and efficacy of anlotinib in recurrent or metastatic esophageal squamous cell carcinoma

Objective:In this post-hoc analysis,we evaluated anlotinib treatment-induced hypertension as a potential predictive factor of efficacy in esophageal squamous cell carcinoma(ESCC)patients.Methods:A total of 109 patients enrolled in the anlotinib group in a phase 2 trial were included.The tumor response was assessed by computed tomography at week 3,week 6,and then every 6 weeks until progressive disease was observed.The primary endpoint of the study was progression free survival(PFS).The secondary endpoints included overall survival(OS)and objective response rate(ORR).Results:In all patients,the median PFS was 3.02 months[95%confidence interval(CI):2.63–3.65 months]and the OS was 6.11 months(95%CI:4.40–7.79 months).The ORR was 7.34%(95%CI:3.22%–13.95%).A total of 59(54%)patients were diagnosed with treatment-induced hypertension(Group A),and the remaining patients(n=50,46%)were in Group B.Baseline prognostic factors were similar between the 2 groups.Patients in Group A had a longer PFS and OS and higher ORR.When stratifying patients using a previously known history of hypertension,treatment-induced hypertension was a predictor only for patients without previous hypertension,who had longer PFS[hazard ratio(HR):0.40,95%CI:0.24–0.68]and OS(HR:0.37,95%CI:0.21–0.67).Conclusions:We showed,for the first time,a correlation between treatment-induced hypertension and better prognoses in recurrent or metastatic ESCC patients treated with anlotinib,without a previously known history of hypertension.Treatment-induced hypertension may be a simple and low cost predictor for anlotinib antitumor efficacy in these patients,which may also reflect the intended target inhibition.

PREPARATION OF GENE-VIRAL THERAPEUTIC SYSTEM CNHK200-HA AND ITS ANTITUMOR ACTIVITY ON LUNG CANCER

Objective： To develop a novel adenoviral vector system, which combines the advantages of the antiangiogenic gene therapy and virus therapy, and to investigate its antitumor activity on lung cancer. Methods： A new kind of viral vector CNHK200, in which the Elb55kDa gene was deleted and the whole Ela gene was preserved, was constructed. Human angiostatin gene Kringle 1-5 （hA） was amplified and inserted into the genome of the replicative virus CNHK200, generating CNHK200-hA. The expression of hA and its effect on lung cancer cell growth in vitro and in vivo were studied. Results： The novel vector system CNHK200-hA, just like the replicative virus ONYX-015, replicated in p53-deficient tumor cells but not in normal cells, and thus specifically killed tumor cells. In in vitro experiment, both CNHK200-hA and the non-replicative virus Ad-hA could kill tumor cells but the latter needed 100 times more MOI to achieve the same level of cell killing. In in vivo experiment, the therapeutic effect of CNHK200-hA on human lung cancer A549 xenografts in nude mice was significantly better than that of Ad-hA or that of ONYX-015. Conclusion： CNHK200-hA, which carries the angiostatin gene, has the advantages of specific tumor targeting, high expression of transgene in tumor cells and potent antitumor activity.

Inhibitory Effects of TNP-470 in Combination with BCNU on Tumor Growth of Human Glioblastoma Xenografts

This study investigated the effect of TNP-470 in combination with carmustine (BCNU) on the growth of subcutaneously implanted human glioblastoma xenografts in nude mice.Human glioblastoma U-251 cells (1×10 7) were injected into 24 nude mice subcutaneously.The tumor-bearing mice were randomly divided into 4 groups on the seventh day following tumor implantation:TNP-470 group,in which TNP-470 was given 30 mg/kg subcutaneously every other day 7 times;BCNU group,in which 20 mg/kg BCNU were injected into peritoneal cavity per 4 days 3 times;TNP-470 plus BCNU group,in which TNP-470 and BCNU were coadministered in the same manner as in the TNP-470 group and the BCNU group;control group,in which the mice were given 0.2 mL of the mixture including 3% ethanol,5% acacia and 0.9% saline subcutaneously every other day 7 times.The tumor size and weights were measured.The tumor microvessel density (MVD) was determined by immunostaining by using goat-anti-mouse polyclonal antibody CD105.The results showed that on the 21th day following treatment,the volume of xenografts in the TNP-470 plus BCNU group was (108.93±17.63)mm 3,markedly lower than that in the TNP-470 group [(576.10±114.29)mm 3 ] and the BCNU group [(473.01±48.04)mm 3 ] (both P【0.01).And the xenograft volume in these 3 treatment groups was even much lower than that in the control group [(1512.61±470.25) mm 3 ] (all P【0.01).There was no significant difference in the volume of xenografts between the TNP-470 group and the BCNU group (P】0.05).The inhibition rate of the tumor growth in the TNP-470 plus BCNU group was (92.80±11.37)%,notably higher than that in the TNP-470 group [(61.91±6.29)%] and the BCNU group [(68.73±9.65)%] (both P【0.01) on the 21th day following treatment.There was no significant difference in the inhibition rate of tumor growth between the TNP-470 group and the BCNU group (P】0.05).The MVD of xenografts in the TNP-470 plus BCNU group was decreased significantly as compared with that in the TNP-470 group or the BCNU group (both P【0.05).The MVD of xenografts in the 3 treatment groups was markedly reduced as compared with that in the control group (all P【0.05).No significant changes in weights were observed before and after the treatment in each group (all P】0.05).It was concluded that the combination of TNP-470 and BCNU can significantly inhibit the growth of human glioblastoma xenografts in nude mice without evident side effects.

Melatonin: A Powerful Integrative Adjunctive Agent for Oncology

Melatonin is an established hormone supplement and has been well recognized for its effect on the circadian cycle to improve sleep, REM (rapid eye movement), and aiding in jetlag recovery. The utility of melatonin extends beyond sleep aid, however. This hormone also possesses less well-known antioxidant action and even robust anticancer activity. Melatonin may be a key supplement for addressing age-related neurologic decline while serving as a valuable adjunctive cancer treatment that reduces drug resistance in tumors and downregulates angiogenesis. In immunotherapy, melatonin activates Natural Killer (NK) cells nested within tumoral tissue and does not have the side effect profile of other immunoreactive agents used for chemotherapy. Since melatonin is found in high concentrations in the brain and other hormone-linked tissues, the relevance of melatonin is increased for the treatment of estrogen-linked cancers. The immunomodulatory effect of melatonin may also help with chronic inflammation seen in patients with autoimmune disorders. All of these effects together represent a unique and versatile therapeutic agent for integrative medicine. No other commercially available drug possesses all of these therapeutic mechanisms while having a very minimal side effect profile and being considered overall to be safe to use. Currently, melatonin is underutilized in medicine, especially in the field of integrative oncology and represents a crucial supportive adjuvant to improve the lives of patients.

Fabrication of microwave-sensitized nanospheres of covalent organic framework with apatinib for tumor therapy

A new nanocomposite of hollow covalent organic framework(COF)conjugated with the apatinib(AP)and loading microwave-sensitizer(ionic liquid,IL)was prepared by layer by layer(LBL)method and hyaluronic acid(HA)coating,named as COF-AP-IL@HA.AP loading rate in COF hollow-spheres(~30 nm shell thickness)was~40.3%,due to the interactions of hydrogen andπ-πbonds between AP and COF shell,and acidic environment destroyed COF structure,promoting AP release.Microwave sensitization of loaded IL in COF hollow-spheres could enhance the microwave heat-effect,and combined AP therapeutic ability,leading to their higher inhibitation on tumor,due to targeting ability of HA and the local release of apatinib.88.9%of inhibition rate of COF-AP-IL@HA under microwave on the in vivo tumor was significantly higher than those without microwave(12.3%)and COF-IL@HA with microwave(37.5%),indicating a synergism of sensitized microwave hyperthermia and AP therapy on the reduced expression of VEGF via the downregulation pathway of hypoxia inducible factor.These results indicated that COF-AP-IL@HA was potential to the application in the combination therapy of tumor of the sensitized microwave hyperthermia and apatinib.

Manipulation of immune-vascular crosstalk:new strategies towards cancer treatment

Tumor vasculature is characterized by aberrant structure and function,resulting in immune suppressive profiles of tumor microenvironment through limiting immune cell infiltration into tumors,endogenous immune surveillance and immune cell function.Vascular normalization as a novel therapeutic strategy tends to prune some of the immature blood vessels and fortify the structure and function of the remaining vessels,thus improving immune stimulation and the efficacy of immunotherapy.Interestingly,the presence of"immune-vascular crosstalk"enables the formation of a positive feedback loop between vascular normalization and immune reprogramming,providing the possibility to develop new cancer therapeutic strategies.The applications of nanomedicine in vascular-targeting therapy in cancer have gained increasing attention due to its specific physical and chemical properties.Here,we reviewed the recent advances of effective routes,especially nanomedicine,for normalizing tumor vasculature.We also summarized the development of enhancing nanoparticle-based anticancer drug delivery via the employment of transcytosis and mimicking immune cell extravasation.This review explores the potential to optimize nanomedicine-based therapeutic strategies as an alternative option for cancer treatment.

Inhibition of tumor growth in xenografted nude mice with adenovirus-mediated endostatin gene comparison with recombinant endostatin protein

Background Inhibition of tumor growth by endostatin has been shown to be an effective strategy in cancer therapy in mice However, its widespread application has been hampered by difficulties in a large scale production of the recombinant endostatin protein, rapid loss bioactivity of the protein, and the cumbersome daily administration These limitations could be resolved by in vivo delivery and expression of the endostatin gene In this study, we observed the effect and advantage of endostatin gene therapy mediated by a recombinant adenoviral vector (Ad/hEndo) on the growth of hepatocellular carcinoma BEL 7402 xenografted tumors, comparison with recombinant endostatin protein Methods Hepatocellular carcinoma BEL 7402 cells were inoculated subcutaneously in the flank of Balb/c nude mice Nine days after tumor cell inoculation, animals were given a cycle of four courses of intra tumoral injections of Ad/hEndo of 5×10 8 pfu (low dose group) and 1×10 9 pfu (high dose group) at intervals of six days, respectively Recombinant human endostatin protein (rhEndo) was administrated daily subcutaneously at a dose of 10 mg·kg 1 ·d 1 at a site nearby the tumor for ten days The expression of endostatin mRNA in tumor tissue was analyzed by reverse transcription polymerase chain reaction (RT PCR) after Ad/hEndo injection Dynamic changes of concentration of endostatin protein in tumor tissue were quantitated by enzyme linked immunosorbent assay (ELISA) Results After 4 courses of treatment, the tumor growth rates of high dose treated group with 1×10 9 pfu of Ad/hEndo were inhibited by 42 26% compared with the Ad/ LacZ control group ( P =0 001) and by 46 26% compared with the NIH buffer control group ( P =0 003), respectively However, in this study, Ad/hEndo at low dose of 5×10 8 pfu failed to demonstrate significant inhibition of tumor growth, compared with control groups After daily administration of recombinant human endostatin protein (rhEndo) for 9 days, the ratio of T/C (rhEndo group versus PBS group) was less than 47% However, two days after rhEndo treatment ceased, the ratio of T/C was more than 50% The peak of expression of endostatin mRNA in tumor tissue was at 2 or 3 days after administration intratumorally with Ad/hEndo of 1×10 9 pfu and gradually dropped undetectable by day 7 Dynamic analysis of endostatin concentration in tumor tissue showed that the highest level of mRNA is up at the third day after injection, and dropped to basal level three weeks later Conclusions Endostatin gene therapy mediated by a recombinant adenoviral vector had significantly inhibited the growth of hepatocellular carcinoma BEL 7402 xenografted tumors at a high dose of 1×10 9 pfu compared with other groups The analysis of dynamic expression of endostatin in vivo indicated that Ad/hEndo had acquired a high level, relatively long term expression in vivo and bioactivity capability

Improving antitumor immunity using antiangiogenic agents:Mechanistic insights,current progress,and clinical challenges

Cancer immunotherapy,especially immune checkpoint blockade(ICB),has revolutionized oncology.However,only a limited number of patients benefit from immunotherapy,and some cancers that initially respond to immunotherapy can ultimately relapse and progress.Thus,some studies have investigated combining immunotherapy with other therapies to overcome resistance to monotherapy.Recently,multiple preclinical and clinical studies have shown that tumor vasculature is a determinant of whether immunotherapy will elicit an antitumor response;thus,vascular targeting may be a promising strategy to improve cancer immunotherapy outcomes.A successful antitumor immune response requires an intact“Cancer-Immunity Cycle,”including T cell priming and activation,immune cell recruitment,and recognition and killing of cancer cells.Angiogenic inducers,especially vascular endothelial growth factor(VEGF),can interfere with activation,infiltration,and function of T cells,thus breaking the“Cancer-Immunity Cycle.”Together with immunostimulation-regulated tumor vessel remodeling,VEGF-mediated immunosuppression provides a solid therapeutic rationale for combining immunotherapy with antiangiogenic agents to treat solid tumors.Following the successes of recent landmark phase III clinical trials,therapies combining immune checkpoint inhibitors(ICIs)with antiangiogenic agents have become first-line treatments for multiple solid tumors,whereas the efficacy of such combinations in other solid tumors remains to be validated in ongoing studies.In this review,we discussed synergies between antiangiogenic agents and cancer immunotherapy based on results from preclinical and translational studies.Then,we discussed recent progress in randomized clinical trials.ICI-containing combinations were the focus of this review because of their recent successes,but combinations containing other immunotherapies were also discussed.Finally,we attempted to define critical challenges in combining ICIs with antiangiogenic agents to promote coordination and stimulate collaboration within the research community.

Efficacy and safety of first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer： a meta-analysis

Background What benefits and toxicities patients acquire from the use of bevacizumab combined with first-line chemotherapy remains controversial.This study was performed to evaluate the efficacy and safety of first-line chemotherapy plus bevacizumab in patients with metastatic colorectal cancer （mCRC）.Methods Several databases,including PubMed,Embase,and Cochrane Library,were searched up to April 30,2013.Eligible studies were only randomized,controlled trials （RCTs） with a direct comparison between mCRC patients treated with and without bevacizumab.Overall risk ratio （RR）,hazard ratio （HR）,odds ratio （OR）,and 95％ confidence intervals （CO were calculated employing fixed or random-effects models depending on the heterogeneity of the included trials.Results Six RCTs,including 1582 patients in chemotherapy plus bevacizumab group and 1484 patients in chemotherapyalone group,were included.Overall,the addition of bevacizumab to first-line chemotherapy increased overall response rate （ORR） by 4.5％,prolonged both progression-free survival （PFS） and overall survival （OS）,and increased the rate of total Grades 3 or 4 adverse events （G3/4AEs） by 6.9％.Significant differences were found in ORR （RR=1.22 （95％ CI 1.01-1.46）,P=0.03）,PFS （HR=0.60 （95％ Cl 0.47-0.77）,P ＜0.0001）,OS （HR=0.83 （95％ Cl 0.70-0.97）,P=0.02）,and any G3/4AEs （OR=1.56 （95％ Cl 1.29-1.89）,P ＜0.00001）.Conclusion Bevacizumab is a valuable addition to the current first-line chemotherapy regimens used in patients with mCRC,because of conferring a significant improvement in ORR,PFS,and OS,even though it increased adverse events.

Antioxidant, antiangiogenic and antiproliferative activities of root methanol extract of Calliandra portoricensis in human prostate cancer cells

OBJECTIVE： Prostate cancer（PCa） is a major health concern. Calliandra portoricensis（CP） is traditionally known for its analgesic, anti-ulcerogenic and anticonvulsant properties. However, its antiproliferative properties for PCa still need to be investigated. METHODS： Antioxidant activities of CP were determined by 1,1-diphenyl-2-picryhydrazyl（DPPH） and hydroxyl（OH-） radicals-scavenging methods. PC-3 and LNCa P（androgen-refractory and androgendependent PCa-derived cell lines） were cultured and treated with CP（10, 50 and 100 μg/m L）. Effects of CP on cells were determined by cytotoxicity assay（lactate dehydrogenase, LDH） and viability assay（sodium 3′-[1-（phenylaminocarbonyl）-3,4-tetrazolium]-bis（4-methoxy-6-nitro） benzene sulfonic acid hydrate, XTT）. DNA fragmentation was detected by cell death detection enzyme-linked immunosorbent assay plus kit. CP was tested as an inhibitor of angiogenesis using chicken chorioallantoic membrane（CAM） assay. RESULTS： CP showed significant scavenging of DPPH and OH- radicals. CP significantly（P〈0.05） inhibited lipid peroxidation in a dose-dependent manner. Precisely, CP（10, 50 and 100 μg/m L） inhibited PC-3 and LNCa P growth by 7%, 74% and 92%, and 27%, 73%, and 85% respectively at 48 h. CP had low toxicity in vitro at its half inhibitory concentration dose. Detection of cell death induced by CP at 50 μg/m L showed higher enrichment factors in LNCa P（7.38±0.95） than PC-3（3.48±0.55）. Also, treatment with CP（50 μg/m L） significantly reduced network of vessels in CAM, suggesting its antiangiogenic potential. CONCLUSION： Calliandra portoricensis elicited antioxidant, antiangiogenic and antiproliferative effects in PCa cells.

A peptide fusion protein inhibits angiogenesis and tumor growth by blocking VEGF binding to KDR

Vascular endothelial growth factor (VEGF) binding to its tyrosine kinase receptors (KDR/FLK1, Flt-1) induces angiogenesis. In search of the peptides blocking VEGF binding to its receptor KDR/FLK1 to inhibit tumor-angiogenesis and growth, we screened a phage display pep-tide library with KDR as target protein, and some candidate peptides were isolated. In this study, we cloned the DNA fragment coding the peptide K237 from the library, into a vector pQE42 to express fusion protein DHFR-K237 in E. coli M15. The affection of fusion protein DHFR-K237 on endothelial cell proliferation and angiogenesis was investigated. In vitro, DHFR-K237 could completely block VEGF binding to KDR and significantly inhibit the VEGF-medi-ated proliferation of the human vascular endothelial cells. In vivo, DHFR-K237 inhibited angiogenesis in chick embryo chorioa- llantoric membrane and tumor growth in nude mice. These results suggest that K237 is an effective antagonist of VEGF binding to KDR, and could be a potential agent

Angiostatin K(1-3) gene for treatment of human gliomas: an experimental study

To discuss the feasibility of gene therapy of human glioma by antiangiogenesis method Methods Angiostatin K(1 3) cDNA with secretive signal was inserted into the polylinker sites of eukaryotic expression vector pcDNA3 to construct pcDNA SAK(1 3) The vector was transfected into human SHG44 glioma cells by lipofectamine and the positive clone was screened by G418 The biological characteristics of glioma cells were examined by electronmicroscope and flow cytometry The activity of angiostatin K(1 3) protein expressed by SHG44 cells was examined by the bovine micrangium endotheliocyte inhibition assay and immunofluorescence assay When SHG44 cells were implanted into the strata subcutaneum of nude mice, tumor necrosis and micrangium were calculated immunohistochemically and electronmicroscopically for determining their charac^teristics and validity in gene therapy of human glioma by antiangiogenesis method Results The eukaryotic expression vector pcDNA SAK(1 3) was successfully constructed and transfected into glioma cells The cells expressed angiostatin K(1 3) protein, and their tumorigenesis and angiogenesis in nude mice were greatly reduced Conclusion Angiostatin K(1 3) gene is feasible to treat human glioma This experiment lays a foundation for gene therapy of the other solid tumors by antiangiogenesis method

Ultrasound activatable antiangiogenic sonosensitizer for VEGFR associated glioblastoma tumor models

Angiogenic signaling pathway is a major contributing factor in cancer recurrence and progression,which can cause significantly reduced treatment outcomes,especially in the oxygen-dependent photo-and sonodynamic therapies.VEGF and its receptor(VEGFR)play a crucial role in angiogenesis progression;precisely,upregulated VEGF signaling ismainly associated with angiogenesis progression in many types of cancers.Herein,we report a sunitinib-conjugated sonosensitizer(TK-RB:tyrosine kinase-rose bengal)to enhance the anticancer efficacy through VEGF inhibitionmediated antiangiogenesis in conjunction with cellular/tumor damage by ROS generated under ultrasound irradiation.TK-RB reveals good selectivity and cytotoxicity toward VEGFR-positive cells(U87MG)over VEGFR-negative cells(MCF-7).The fluorescent imaging analysis in vivo/ex vivo and the tumor growth investigation in nude mice with U87MG glioblastoma tumor xenografts demonstrate that rose bengal having tyrosine kinase inhibitor(TK-RB)provides an enhanced antitumor effect.The current strategy will make a great contribution to optimizing anticancer performance by utilizing sonodynamic therapy together with antiangiogenics in several different malignancies.