title: In Vivo Loss of Function Screening Reveals Carbonic Anhydrase IX as a Key Modulator of Tumor Initiating Potential in Primary Pancreatic Tumors.
abstract: Reprogramming of energy metabolism is one of the emerging hallmarks of cancer. Up-regulation of energy metabolism pathways fuels cell growth and division, a key characteristic of neoplastic disease, and can lead to dependency on specific metabolic pathways. Thus, targeting energy metabolism pathways might offer the opportunity for novel therapeutics. Here, we describe the application of a novel in vivo screening approach for the identification of genes involved in cancer metabolism using a patient-derived pancreatic xenograft model. Lentiviruses expressing short hairpin RNAs (shRNAs) targeting 12 different cell surface protein transporters were separately transduced into the primary pancreatic tumor cells. Transduced cells were pooled and implanted into mice. Tumors were harvested at different times, and the frequency of each shRNA was determined as a measure of which ones prevented tumor growth. Several targets including carbonic anhydrase IX (CAIX), monocarboxylate transporter 4, and anionic amino acid transporter light chain, xc- system (xCT) were identified in these studies and shown to be required for tumor initiation and growth. Interestingly, CAIX was overexpressed in the tumor initiating cell population. CAIX expression alone correlated with a highly tumorigenic subpopulation of cells. Furthermore, CAIX expression was essential for tumor initiation because shRNA knockdown eliminated the ability of cells to grow in vivo. To the best of our knowledge, this is the first parallel in vivo assessment of multiple novel oncology target genes using a patient-derived pancreatic tumor model.
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA. Electronic address: poren@medimmune.com.
authors.forename: Nabendu
authors.initials: N
authors.lastname: Pore
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA.
authors.forename: Sanjoo
authors.initials: S
authors.lastname: Jalla
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Liu
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA.
authors.forename: Brandon
authors.initials: B
authors.lastname: Higgs
authors.affiliation: ARC-NET Research Centre and Department of Pathology and Diagnostics, University of Verona Medical School, Verona, Italy.
authors.forename: Claudio
authors.initials: C
authors.lastname: Sorio
authors.affiliation: ARC-NET Research Centre and Department of Pathology and Diagnostics, University of Verona Medical School, Verona, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Scarpa
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Hollingsworth
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Tice
authors.affiliation: MedImmune, LLC, Gaithersburg, MD, USA. Electronic address: Michelottie@medimmune.com.
authors.forename: Emil
authors.initials: E
authors.lastname: Michelotti
mesh_terms: D000818:Animals; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases / Q000737:chemistry* / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000502:physiology; D005434:Flow Cytometry; D006801:Humans; D051379:Mice; D018345:Mice, Knockout; D014411:Neoplastic Stem Cells / Q000378:metabolism / Q000473:pathology*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000473:pathology*; D012333:RNA, Messenger / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C499308:Rag2 protein, mouse; D000071231:Carbonic Anhydrase IX; D002256:Carbonic Anhydrases; C492796:Car9 protein, mouse