Ankyrin Repeat Domain 1, ANKRD1 , a Novel Determinant of Cisplatin Sensitivity Expressed in Ovarian Cancer LyndeeL.Scurr, 1,2 AlexanderD.Guminski, 1,2,3 Yoke-EngChiew, 1,2 RosemaryL.Balleine, 1,5 RaghwaSharma, 4 YingLei, 1,2 KyliePryor, 1,2 GerardV.Wain, 2 AlisonBrand, 2 KarenByth, 6 CatherineKennedy, 1,2 HelenRizos, 1 PaulR.Harnett, 1,3 andAnnadeFazio 1,2 Abstract Purpose: The standardof care for ovarian cancer includes platinum-based chemotherapy. It is not possible, however, to predict clinical platinum sensitivity or to design rational strategies to overcomeresistance.Weusedanovelapproachtoidentifyalteredgeneexpressionassociated with high sensitivity to cisplatin, to define novel targets to sensitize tumor cells to platins and ultimately improve the effectiveness of this widely used class of chemotherapeutics. Experimental Design: Using differential display PCR, we identified genes differentially expressed in a mutagenized cell line with unusual sensitivity to cisplatin.The most highly differentially expressed gene was selected, and its role in determining cisplatin sensitivity was validated by gene transfection and small interfering RNA (siRNA) approaches, by associ- ation of expression levels with cisplatin sensitivity in cell lines, and by association of tumor expression levels with survival in a retrospective cohort of 71patients with serous ovarian adenocarcinoma. Results: Themosthighlydifferentlyexpressedgeneidentifiedwas ANKRD1 ,ankyrinrepeat domain1(cardiacmuscle). ANKRD1 mRNAlevelswerecorrelatedwithplatinumsensitivityincell lines,andmostsignificantly,decreasing ANKRD1 usingsiRNAincreasedcisplatinsensitivity >2-fold. ANKRD1 wasexpressedinthemajorityofovarianadenocarcinomastested(62/71, 87%),andhighertumorlevelsof ANKRD1 werefoundinpatientswithworseoutcome(overall survival, P =0.013). Conclusions: These findings suggest that ANKRD1, agenenotpreviouslyassociatedwith ovariancancerorwithresponsetochemotherapy,isassociatedwithtreatmentoutcome,and decreasing ANKRD1 expression, or function, is a potential strategy to sensitize tumors to platinum-baseddrugs. Platinum compounds are the worldwide standard chemother- apy for epithelial ovarian carcinoma and are also widely used in patients with cancers arising in other reproductive organs, the lung, upper aerodigestive tract, and urothelium. Although these agents are initially effective in the majority of ovarian cancer patients, there are significant differences in the tumor response among individuals. Consequently, although a small subgroup of ovarian cancer patients are cured by primary treatment, the more common experience is disease relapse after a variable interval, and some patients with primary resistant disease progress during first-line chemotherapy (1). Currently, it is not possible to accurately predict the clinical course of ovarian cancer patients, and a better understanding of the molecular pathways involved is needed to improve treatment outcomes. Although platins interact with many intracellular compo- nents, their cytotoxic effect is attributed to the formation of DNA interstrand and intrastrand cross-links (reviewed in ref. 2). These platinum-DNA adducts are recognized by a number of proteins, including those involved in nucleotide excision repair, mismatch repair, and high-mobility-group proteins (such as HMG1 and HMG2). Increasing resolution of these pathways Cancer Therepy: Preclinical Authors’ Affiliations: 1 WestmeadInstituteforCancerResearch,Universityof SydneyattheWestmeadMillenniumInstitute;Departmentsof 2 Gynaecological Oncology, 3 MedicalOncologyandPalliativeCare,and 4 AnatomicalPathology, WestmeadHospital; 5 DepartmentofTranslationalOncology,Westmeadand NepeanHospitals;and 6 WestmeadMillenniumInstitute,Westmead,NewSouth Wales,Australia Received12/18/07;revised4/18/08;accepted5/21/08. Grant support: A.D.GuminskiwassupportedbyaNationalHealthandMedical ResearchCouncilPost-GraduateMedicalScholarship;R.L.BalleineandH.Rizos areCancerInstituteNSWFellows;theWestmeadGynaecologicalOncologyTissue BankisamemberoftheAustralasianBiospecimensNetwork-Oncologygroup whichisfundedbytheAustralianNationalHealthandMedicalResearchCouncil; the project was also funded by the Gynaecological Oncology Research Fund, WestmeadHospital,andtheCancerCouncilNewSouthWales. Thecostsofpublicationofthisarticleweredefrayedinpartbythepaymentofpage charges.Thisarticlemustthereforebeherebymarked advertisement inaccordance with18U.S.C.Section1734solelytoindicatethisfact. Note: SupplementarydataforthisarticleareavailableatClinicalCancerResearch Online(http://clincancerres.aacrjournals.org/). L.L.ScurrandA.D.Guminskicontributedequallytothiswork. Requests for reprints: DepartmentofGynaecologicalOncology,TheUniversity ofSydney,WestmeadHospital,Westmead,NSW2145,Australia.Phone: 61-2- 9845-7376;Fax:61-2-9845-7793;E-mail:anna__defazio@wmi.usyd.edu.au. F 2008AmericanAssociationforCancerResearch. doi:10.1158/1078-0432.CCR-07-5189 www.aacrjournals.org Clin Cancer Res 2008;14(21) November 1, 2008 6924 Research. on April 24, 2020. © 2008 American Association for Cancer clincancerres.aacrjournals.org Downloaded from