BrivanibAlaninate,aDualInhibitorofVascularEndothelialGrowth FactorReceptorandFibroblastGrowthFactorReceptorTyrosine Kinases,InducesGrowthInhibitioninMouse ModelsofHumanHepatocellularCarcinoma HungHuynh, 1 VanChanhNgo, 1 JosephFargnoli, 4 MarkAyers, 5 KheeCheeSoo, 2 HengNungKoong, 2 ChoonHuaThng, 1 HockSooOng, 2 AlexanderChung, 2 PierceChow, 3 PamelaPollock, 6 SaraByron, 6 andEvelynTran 1 Abstract Purpose: Hepatocellularcarcinoma(HCC)isthefifthmostcommonprimaryneoplasm;surgery is the only curative option but 5-year survival rates are only 25% to 50%.Vascular endothelial growthfactor(VEGF)andfibroblastgrowthfactor(FGF)areknowntobeinvolvedingrowth andneovascularizationof HCC.Therefore, agents that target these pathways may be effective in the treatment of HCC.The aim of this study was to determine the antineoplastic activity of brivanibalaninate,adualinhibitorofVEGFreceptor(VEGFR)andFGFreceptor(FGFR)signaling pathways. ExperimentalDesign: Six different s.c. patient-derived HCC xenografts were implanted into mice.Tumor growth was evaluated in mice treated with brivanib compared with control.The effects of brivanib on apoptosis and cell proliferation were evaluated by immunohistochemistry.TheSK-HEP1andHepG2cellswereusedtoinvestigatetheeffectsof brivanib on theVEGFR-2 and FGFR-1signalingpathways in vitro.Westernblottingwasusedto determinechangesinproteinsinthesexenograftsandcelllines. Results: Brivanibsignificantlysuppressedtumorgrowthinfiveofsixxenograftlines.Further- more,brivanib^inducedgrowthinhibitionwasassociatedwithadecreaseinphosphorylated VEGFR-2 atTyr 1054/1059 , increasedapoptosis, reduced microvessel density, inhibitionof cell proliferation, and down-regulation of cell cycle regulators.The levels of FGFR-1and FGFR-2 expressioninthesexenograftlines werepositivelycorrelated withits sensitivity tobrivanib- inducedgrowthinhibition.InVEGF-stimulatedandbasicFGFstimulatedSK-HEP1cells,brivanib significantlyinhibitedVEGFR-2,FGFR-1,extracellularsignal-regulatedkinase1/2,andAktphos- phorylation. Conclusion: Thisstudyprovidesastrongrationaleforclinicalinvestigationofbrivanibinpatients withHCC. Hepatocellular carcinoma (HCC) is the fifth most common primary neoplasm, accounting for approximately 667,000 deaths worldwide annually (1, 2). Recurrence, metastasis, or the development of new primary tumors is the most common cause of mortality for patients with HCC (3, 4). Surgery is the only proven potentially curative therapy for HCC; however, only 10% to 20% of patients undergo surgery because of poor liver function, metastases, or both (5–7), and of those having surgery, the 5-year survival rate is only 25% to 50%. Several chemotherapeutic agents have been evaluated for the treatment of HCC; however, no single or combination chemotherapy regimen is particularly effective (8). Doxorubicin is the most widely used agent in HCC; studies have shown a 4% to 10.5% response rate in patients with HCC (9, 10). However, the overall response rate, but not overall survival, was shown to double when doxorubicin was given in combination with cisplatin, IFN, and 5-fluorouracil (10). The multitargeted tyrosine kinase inhibitor sorafenib (Nexavar, Bayer and Onyx Pharmaceuticals), which inhibits vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor recep- tor, raf, c-kit, and flt-3, has been shown to inhibit HCC-induced proliferation and angiogenesis (11). More recently, sorafenib has been shown to provide a significant improvement in overall Cancer Therapy: Preclinical Authors’Affiliations: 1 LaboratoryofMolecularEndocrinology,DivisionofCellular andMolecularResearch,NationalCancerCentre;Departmentsof 2 GeneralSurgery and 3 Experimental Surgery, Singapore General Hospital, Singapore, Singapore; 4 DiscoveryBiologyand 5 DiscoveryMedicineandClinicalPharmacology,Bristol- Myers Squibb, Princeton, NewJersey; and 6 Cancerand Cell Biology Division, TranslationalGenomicsResearchInstitute,Phoenix,Arizona Received2/25/08;revised4/24/08;accepted5/7/08. Grantsupport: SingaporeCancerSyndicategrantsSCS-AS0032,SCS-HS0021, andSCS-AMS0086(H.Huynh). Thecostsofpublicationofthisarticleweredefrayedinpartbythepaymentofpage charges.Thisarticlemustthereforebeherebymarked advertisement inaccordance with18U.S.C.Section1734solelytoindicatethisfact. Requestsforreprints: HungHuynh,Laboratoryof Molecular Endocrinology, DivisionofCellularandMolecularResearch,NationalCancerCentreofSingapore, Singapore169610,Singapore.Phone:65-436-8347;Fax:65-226-5694;E-mail: cmrhth@nccs.com.sg. F 2008AmericanAssociationforCancerResearch. doi:10.1158/1078-0432.CCR-08-0509 www.aacrjournals.org ClinCancerRes2008;14(19)October1,2008 6146 Downloaded from http://aacrjournals.org/clincancerres/article-pdf/14/19/6146/1978133/6146.pdf by guest on 19 June 2022