抗癌症复合高分子材料的简介.pdf
ReviewAnticancer activity of polyoxomolybdateH.Yanagiea,*,A.Ogatab,S.Mitsuib,T.Hisaa,T.Yamaseb,M.EriguchiaaDepartment of Intellectual Property,Project of Cancer Metastasis Inhibition,Research Center for Advanced Science and Technology,The University of Tokyo,4-6-1 Komaba,Meguro-ku,Tokyo 153-8904,JapanbChemical Research Laboratory,Tokyo Institute of Technology,R1-21,4259 Nagatsuta,Midori-ku,Yokohama 226-8503,and“Creation of bio-devices and bio-systems with chemical and biological molecules for medical use”,CREST,Japan Science and Technology Agency(JST),JapanReceived 8 February 2006;accepted 22 February 2006Available online 30 June 2006AbstractAnticancer polyoxomolybdates have been investigated for medical application of polyoxometalates as discrete cluster anions of metal oxides.NH3Pri6Mo7O243H2O(PM-8)has been recognized as one of significant antitumoral polyoxomolybdates.PM-8 had shown the growth sup-pression against several tumors,for examples,Co-4,human colon cancer,MX-1,human breast cancer,and OAT,human lung cancer.PM-8showed the tumor growth suppression for MKN-45 human gastric cancer in tumor bearing mice.PM-8 inhibited the cell growth of AsPC-1which depended on the dose with showing DNA ladder formation and DNA fragmentation,and positive Hoechst staining indicating apoptosis.The ratio of apoptotic cells on flow cytometry analysis were 35%,and 57%with treatment of PM-8 after 48,and 72 h,respectively.One of theanti-tumor activity of PM-8 result from the activation of apoptotic pathway.It is thought that polyoxomolybdates will be applied as a novel anti-tumor agent especially against cancers which are difficult to be treated clinically.2006 Elsevier SAS.All rights reserved.Keywords:Polyoxomolybdate;Cancer growth inhibition;Apoptosis;Redox reaction1.BackgroundPolyoxometalates,the discrete polymeric anions of earlytransition metal oxide,form a large class of inorganic com-pound with great molecular diversity and significant potentialapplications in analytical chemistry,material science,catalysis,and medicine.Polyoxometalates are negatively charged inor-ganic substances which contain early transitional metal ionssuch as tungsten(W),molybdenum(Mo),vanadium(V),nio-bium(Nb),antimony(Sb),etc.,and which make a cluster withthe surrounding oxygen atoms.Several polyoxometalates has been reported to inhibit thereplication of the human immunodeficiency virus(HIV)16,herpes simplex virus(HSV)710,influenza virus(fluV)11,and respiratory syncytial virus(RSV)12.Also,the anti-bacterial activities against methicillin-resistant Staphylococcusaureus(MRSA)13,Streptococcus pneumoniae 14.Yamase 15,16 had reported that significant antitumoral effectofpolyoxomolybdates,especiallyNH3Pri6Mo7O243H2O(PM-8)was found against MX-1 murine mammary cancer cellline,Meth A sarcoma and MM46 adenocarcinoma.The structurethe anion of PM-8 is constructed large open circles oxygen atomsand small closed circles represent Mo atoms 17.PM-8 is water-soluble and structurally stable in aqueous solutions at pH 5718.The polyoxometalates can usually be isolated as ammoniummetallic,or organometallic salts 19.In vivo or in vitro anti-tumor activity of cyclopentadienyltitanium-containing polyoxotungstates has been investigatedalong with the modification of the well-known antitumoralorgano-titano compound 2023.2.Cancer cell cytotoxicity and tumor growth suppressionof polyoxomolybdateSome polyoxometalates such as PM-8,PM-17,PM-26,andPM-32 were found to exhibit anti-tumor activities against Co-4,MX-1,OAT human cancers and Meth A mouse sarcoma usinghttp:/ 60(2006)349352*Corresponding author.Tel.:+81 3 5452 5436;fax:+81 3 5452 5434.E-mail address:yanagieip.rcast.u-tokyo.ac.jp(H.Yanagie).0753-3322/$-see front matter 2006 Elsevier SAS.All rights reserved.doi:10.1016/j.biopha.2006.06.018SRC assay on tumor bearing mice 24.It had been reported thatNH46Mo7O244H2O and K6Mo7O244H2O were effective,whereas NH3PriCl was ineffective against Meth A tumor bear-ing mice 24.Especially,hexakis(isopropylammonium)hepta-molybdate(V1)NH3Pri6Mo7O243H2O exhibited a signifi-cant inhibition on the growth of Meth A sarcoma.The resultsindicate that the polyoxomolybdate structure of the Mo7O24isapparently of critical significance for the antitumor activity.Anderson structural polyoxometalates and V-shaped heptamo-lybdates have been recognized to exhibit antitumor activities atnon-cytotoxic doses in vivo.If the polyoxometalates exhibittheir redox reactions and adsorption ability in/on the cell,it isnecessary to modify the electron-transfer net work in the biolo-gical system 15,16,19,24.PolyoxotungstateCoW11(CpTi)remarkablydecreasedtumor weight of the rats bearing SSMC-7721(liver cancercell),HL-60(leukemia)and HLC(colon cancer cell)in invivo model.The in vivo antitumor activity of CoW11(CpTi)resembles the antitumor drugs of clinical practice cyclopho-sphamide(CP)and 5-fluorouracil(5-FU),but the toxicity ofCoW11(CpTi)is much lower than the latter 13.Cytotoxic effects of PM-8 on the proliferation of humangastric cancer cell line,MKN45 reveals that IC50values ofPM-8 for 24 and 48 h-treatments were 0.90 and 0.50 mg/ml,respectively.The tumor growth suppression on MKN45 tumorbearing mice by PM-8 became twice compared to the controlgroups after 70 days incubation.PM-8 did not induced anyadverse effects such as body weight loss in the host mice.The cytotoxic effects of PM-8 on the proliferation of humanpancreatic cancer cell line,AsPC-1 reveals that IC50values ofPM-8 for 24 and 48 h-treatments were 1.65 and 0.50 mg/ml,respectively 25.3.Anticancer mechanisms of polyoxomolybdateAntitumor mechanism of polyoxometalates is based on theredox reaction.The MoVO5(OH)site in the Mo7O24frameworkexhibits a strong toxicity in contrast to the d0-configuratedMoVIO6site but the antitumoral potency of the former is simi-lar to that of the latter.This provides a clue to the mechanismof the antitumor activity of the Mo7O246to Mo7O23(OH)6is involved in the antitumor mechanism,which leads torepeated cycles of the redox reaction of Eq.(1)in tumor cells16:Mo7O24?6?e?H!Mo7O23OH?6?(1)Yamase et al.had been reported that the modification ofpolyoxometalates is described as follows;(1)the NH3Prication was replaced by NH4+and K+;(2)the Mo7O246anion was replaced by Cl;(3)the reduction of Mo7O246toHXMo7O246in the tumor cells,leading to the specificity oftumor cell killing by HXMo7O246,seems to reflect the anti-tumor potency of Mo7O246.The strong toxicity of the d1configuration in the Mo7O24framework may be explained bythe reduction of the host cells due to the highly negative oxida-tion potential(0.10-HXMo7O246.The plausible redoxreaction between HxMo7O246and host cells results inMo7O246formation and cytotoxicity(due to the reductionof the host cells).Mo7O246produced in the host cells willbe transmitted to the tumor cells and contribute to the tumorcell killing due to the reproduction of HxMo7O246as a resultoftheredoxreactionwiththetumorcells.NH3Pri6HxMo7O24 exhibited a significant inhibition ongrowth of Meth A sarcoma.This results indicated that thestructure of the Mo7O246is apparently important for antic-ancer activity 16.PM-8 inhibited the cell growth of AsPC-1 with showingDNA ladder formation and DNA fragmentation,apoptoticsmall bodies on Hoechst staining and TUNEL staining.Theflow cytometry analysis reveals that the ratio of apoptoticcells increased with the duration of the PM-8 treatment:35%after 48 h of the PM-8 treatment,and 57%after 72 h,whilethere were no apoptotic cells in control.These results indicatedthat one of the mechanisms of cancer cell cytotoxicity is apop-tosis in the cancer cells.The apoptosis was induced in the man-ner of concentrations of PM-8 25.PM-8 exhibited non-specific weak interaction with DNA26.PM-8 can be distinguished from the antitumor mechanismof a mononuclear metal complex such as CDDP and otherorganometallic compounds,because in case of CDDP the dis-sociation of chloride ligands is followed by binding to N-7atoms of guanine bases in DNA and formation of DNA inter-strand crosslinks at clinically achievable concentration 27,28.It has been shown that Mo7O246interacts with flavinmo-nonucleotide(FMN)to yield the 1:1 Mo7O246-FMN com-plex 8,24.Since FMN is a prosthetic group in a flavoproteinand acts as an electron carrier for the electron transfer(fromNADH to coenzyme Q)coupled with the ATP generation atthe site 1 16,therefore,it has been proposed that the forma-tion of the 1:1 Mo7O246FMN complex in mitochondria onthe tumor cell inhibits ATP generation with a resultant antitu-mor activity 8,11,20.Therefore,it may be point out that theinduction of apoptosis by PM-8 is due to blocking the signalpathway derived from the response of mitochondria.Thesehypothesis reveals that the apoptotic pathway may be asso-ciated with this redox hypothesis 15,19,29.It is well known that the PM-8 exhibited non-specific weakinteraction with DNA,different from the case of 5-FU,or cis-platin(CDDP).The mechanism of anti-tumor activity of 5-FUis unformulation of RNA,and that of CDDP is the DNA inter-strand crosslinks derived from adduction of guanine bases 27,28.It is also well known that there are several pathways forthe apoptosis,such as induction of cytochrome C to caspase 9,the induction of caspase 8 to caspase 3 from external stimula-tions or nuclear signalings,and bcl 2 pathway inductions 30.A novel polyoxotungstate CoW11O39(CpTi)7(Cp=5C5H5)exhibits the highest antitumor activity in vitro among thecyclopentadienyltitanium substituted polyoxometalates investi-gated and has a remarkable inhibitory action on three types ofhuman cancer cells,SSMC-7721,HL-60 and HLC,in vivo.Ithas been reported that-SiW9(CpTi)3can degrade the genomicH.Yanagie et al./Biomedicine&Pharmacotherapy 60(2006)349352350DNA.The-SiW9(CpTi3)may have an ability to specificallycleave DNA or to alter the conformation of DNA molecules,implying that the mechanism of antitumor action is attributableto its ability to cleave DNA or to alter the conformation ofDNA molecules 6,13,23.It is also useful to clarify the mechanism of anti-tumoractivity of polyoxometalates,which would be applied to thetheory of suppression of the genomes of HIV,HSV,fluV,RSV,and MRSA 31.It is necessary to investigate the signalpathway analysis of cytotoxicity of polyoxometalates,in vivomodel of anti-tumor growth,and novel development of drugdelivery systems 32,33 using polyoxometalates.AcknowledgementsThe parts of this study is supported by a grant-in-aid forScientific Research of the Ministry of Education,Science,Sport and Culture(The No.15390389 and 15659308 is to Hir-onobu Yanagie),the Grant of Sato memorial foundation forcancer research(to Hironobu Yanagie),and the Grant of“Crea-tion of bio-devices with chemical and biological molecules formedical for medical use”(CREST)of Japan science and tech-nology agency(JST)(to Toshihiro Yamase).References1Sarafianos SG,Kortz U,Pope MT,Modak MJ.Mechanism of polyoxometalate-mediated inactivation of DNA polymerases:an analysis withHIV-1 reverse transcriptase indicates specificity for the DNA-bindingcleft.Biochem J 1996;319:61926.2Inoue Y,Tokutake Y,Yoshida T,Seto Y,Fujita H,Dan K,et al.Invitro antiviral activity of polyoxomolybdates.Mechanism of inhibitoryeffect of PM-104(NH4)12H2(Eu4(MoO4)(H2O)16(Mo7O24)4)13H2O onhuman immunodeficiency virus type 1.Antiviral Res 1993;20(4):31731.3Inoue Y,Fujimoto Y,Sugiyama M,Yoshida T,Yamase T.Structureactivity correlationship and strain specificity of polyoxometalates inanti-human immunodeficiency virus activity.Biol Pharm Bull 1995;18(7):9961000.4Kim GS,Judd DA,Hill CL,Schinazi RF.Synthesis,characterization,and biological activity of a new potent class of anti-HIV agents,theperoxonibium-substituted heteropolytungstates.J Med Chem 1994;37(6):81620.5Cholewa M,Legge GJ,Weigold H,Holan G,Birch CJ.The use of ascanning proton microprobe to observe anti-HIV drugs within cells.Life Sci 1994;54(21):160712.6Weeks MS,Hill CL,Schinazi RF.Synthesis,characterization,and anti-human immunodeficiency virus activity of water-solution salts of poly-oxotungstate anions with covalently attached organic groups.J MedChem 1992;35(7):121621.7Fukuma M,Seto Y,Yamase T.In vitro antiviral activity of polyoxo-tungstate(PM-19)and other polyoxometalates against herpes simplexvirus.Antiviral Res 1991;16(4):32739.8Ikeda S,Nishiya S,Yamamoto A,Yamase T,Nishimura C,De ClercqE.Activity of the Keggin polyoxotungstate PM-19 against herpes sim-plex virus type 2 infection in immunosuppressed mice:role of perito-neal macrophage activation.J Med Virol 1993;41(3):1915.9Dan K,Miyashita K,Seto Y,Fujita H,Yamase T.Mechanism of theprotective effect of heteropolyoxotungstate against herpes simplexvirus type 2.Pharmacology 2003;67:839.10Dan K,Miyashita K,Seto Y,Fujita H,Yamase T.The memory effectof heteropolyoxotungstate(PM-19)pretreatment on infection by herpessimplex virus at the penetration stage.Pharmacological Reseach 2002;46(4):35762.11Shigeta S,Mori S,Watanabe J,Soeda S,Takahashi K,Yamase T.Synergistic anti-influenza virus A(H1N1)activity of PM-523(poly-oxometalate)and rebavirin in vitro and in vivo.Antimicrob Agens Che-mother 1997;41(7):14237.12Kimura K,Ishioka K,Hashimoto K,Mori S,Suzutani T,Bowlin TL,et al.Isolation and characterization of NMSO3-resistant mutants ofrespiratory syncytial virus.Antivir Res 2004;61(3):16571.13Fukuda N,Yamase T,Tajima Y.Inhibitory effect of polyoxotungstateson the production of penicillin-binding proteins and beta-lactamaseagainst methicillin-resistant Staphylococcus aureus.Biol Pharm Bull1999;22(5):46370.14Fukuda N,Yamase T.In vitro antibacterial activity of vanadate andvanadyl compounds against Streptcoccus pneumoniae.Biol PharmBull 1997;20(8):92730.15Yamase T.Polyoxometalates for molecular devices:antitumor activityand luminescence.Mol Eng 1993;3:24162.16Yamase T.Medical chemistry of polyoxometalates.Part 1.Potent anti-tumor activity of polyoxomolybdates on animal transplantable tumorsand human cancer xenograft.Inorg Chim Acta 1988;151:158.17Ohashi Y,Yanagi K,Sasada Y,Yamase T.Crystal structure and photo-chemistry of isopolymolybdates.I.The crystal structure of hexakis(pro-pylammonium)heptamolybdate(VI)trihydrate and hexakis(isopropy-lammonium)heptamolybdate(VI)trihydrate.Bull Chem Soc Jpn 1982;55:125460.18Yamase T,Ikawa T.Photochemical study of the alkylammoniummolybdates.III.Preparation and properties.Bull Chem Soc Jpn 1977;50(3):7469.19Yamase T.Antitumoral and antiviral polyoxometalates(inorganic dis-crete polymer of metal oxide).CRC Press 1996;1:36573.20Maier F,Hesse B,Kopf H.Tumor inhibition by metallocenes:effect oftitanocene,zirconocene,and hafnocene dichlorides on Ehrlich ascitestumor in mice.Cancer research.Clin Oncol 1980;96:4351.21Wang X,Liu J,Li J.Synthesis,characterization and in vitro antitumoractivity of diorganometallo complexes-keggin anions.Inorg ChemCommun 2001;7:3724.22Wang X,Liu,Jingfu,Li J,Yang Y,Liu,Jutao,Li B,Pope MT.Synth-esis and antitumor activity of cyclopentadienyltitanium substituted poly-oxotun
