CANCER CHEMISTRY | MAY 012009
`
`Abstract #4467: Targeting tumor microenvironment with
`radiolabeled inhibitors of seprase (FAP\#945;) ©
`
`John Marquis; Jian Wang; Kevin Maresca; Shawn Hillier; Craig Zimmerman; John Joyal; John Babich
`
`'.) Check for updates
`
`=+ Author & Article Information
`Cancer Res (2009) 69 (9_Supplement): 4467.
`
`m Split-Screen ocg Share v Q% Tools v (¥ Versions v
`
`Abstract
`
`Seprase, also know as fibroblast activating protein alpha (FAP\#945;) is a key component of the
`tumor microenvironment. Its expression is normally restricted to fetal mesenchymal tissue and sites
`of wound healing, but is selectively over expressed in the tumor stroma. It is expressed in cancer-
`associated fibroblasts of greater than 90% of human primary epithelial tumors including breast, lung,
`colorectal, gastric, cervical and ovarian cancers, making it an attractive target to exploit for
`noninvasive radioimaging, as well as targeted radiotherapy of cancer. Seprase is an 88 kDa, type II,
`intregral membrane peptidase in the dipeptidyl peptidase-4 (DPP-IV) family of prolyl peptidases. We
`designed, synthesized and evaluated a series of iodine substituted benzamido-glycine-
`boronoproline analogs as seprase antagonists, with the potential to be radiolabeled with either '#| or
`31| for radiodiagnostic or radiotherapeutic use, respectively. lodine was substituted at the three
`positions of the benzene ring, and compounds were assessed for their ability to inhibit the enzymatic
`activity of recombinant human seprase in a fluorescence based assay. Among the most active
`compounds, an ortho-iodine analog (MIP-1231) displayed an IC ;, of 6 nM, whereas even more
`potent para- (MIP-1232) and meta-substituted (MIP-1233) analogs both had IC ;, values of 0.6 nM.
`To examine the selectivity for seprase over other prolyl peptidases, compounds were tested for their
`ability to inhibit the enzymatic activity of prolyl oligopeptidase (POP), the only other endopeptidase
`in this family of peptidases. The 1C;, values of MIP-1231, MIP-1232, and MIP-1233 for POP were
`58, 19, and 7 nM, respectively, with POP/FAP ratios of 10, 32, and 12, respectively. These data
`demonstrate that although the para- and meta- substituted compounds have similar ability to inhibit
`seprase activity, the para- substituted analog displayed better selectivity. To examine binding to
`Sskei rtaos't\a/l?l%nw?/&n eunr%an embryonic kidney (HEK-293) cells were stably transfected with the human
`seprase gene, and highly expressing clones were selected and verified by Western blotting. MIP-
`1232 was radiolabeled with '?| for saturation binding analysis using the stable seprase expressing
`
`Petitioner GE Healthcare — Ex. 1035, p. 1
`
`
`
`
`
`
`
`
`cells. The K, of MIP-1232 for seprase was determined to be 30 nM, whereas there was no specific
`binding to a non-expressing clone. The B, ,, of the seprase expressing cells was determined to be
`approximately 8 pmol/10° cells. In addition, MIP-1232 was shown to inhibit the seprase enzymatic
`activity of the stable seprase expressing cells. These radiolabeled seprase inhibitors are currently
`being evaluated for tumor uptake and tissue distribution in mice bearing seprase expressing HEK-
`293 xenografts, as well as tumors that promote seprase expression in the tumor associated stroma.
`Radiolabeled seprase inhibitors could be exploited for the diagnosis, staging, prognosis, and
`potential treatment of solid tumors.
`
`Citation Information: In: Proc Am Assoc Cancer Res; 2009 Apr 18-22; Denver, CO. Philadelphia
`(PA): AACR; 2009. Abstract nr 4467.
`
`100th AACR Annual Meeting-- Apr 18-22, 2009; Denver, CO
`
`American Association for Cancer Research
`
`Advertisement
`
`View Metrics
`
`Citing Articles Via
`
`Skip to Main Content
`&) Email Alerts
`
`Article Activity Alert
`
`Petitioner GE Healthcare — Ex. 1035, p. 2
`
`
`
`
`
`
`
`
`eTOC Alert
`
`Latest News
`
`Investigators Note Hazards of Cutting NIH Indirect
`
`Costs
`
`CART Cells Can Arm Other Immune Cells By “Nibbling”
`Them
`
`HERS3-Targeted Bispecific Shrinks Rare Cancers with
`NRG1 Fusions
`
`View more recent articles >
`
`Breaking
`
`Judge Extends Freeze on Proposed NIH Cuts
`
`CDC Vaccine Meeting, First Under RFK Jr.’s Tenure,
`Postponed
`
`Woman Remains Cancer-Free 18-Plus Years After CAR
`T-Cell Therapy
`
`View more recent articles >
`
`Research Watch
`
`Neuroendocrine Differentiation Promotes Lung
`
`Tumorigenesis Via Electrical Activity
`
`Disruption of the SKI Complex Confers Dependency on
`PELO in Cancer
`
`Skip to Main Content
`Early Progenitor Myeloid-Derived Suppressor Cells
`
`Promote Glioblastoma
`
`Petitioner GE Healthcare — Ex. 1035, p. 3
`
`
`
`
`
`
`
`
`View more recent articles >
`
`Issues News
`Online First Twitter
`Collections
`
`Online ISSN 1538-7445 Print ISSN 0008-5472
`
`Petitioner GE Healthcare — Ex. 1035, p. 4
`
`
`
`
`
`
`
`
`