title: Lentiviral vector-based insertional mutagenesis identifies genes involved in the resistance to targeted anticancer therapies.
abstract: The high transduction efficiency of lentiviral vectors in a wide variety of cells makes them an ideal tool for forward genetics screenings addressing issues of cancer research. Although molecular targeted therapies have provided significant advances in tumor treatment, relapses often occur by the expansion of tumor cell clones carrying mutations that confer resistance. Identification of the culprits of anticancer drug resistance is fundamental for the achievement of long-term response. Here, we developed a new lentiviral vector-based insertional mutagenesis screening to identify genes that confer resistance to clinically relevant targeted anticancer therapies. By applying this genome-wide approach to cell lines representing two subtypes of HER2(+) breast cancer, we identified 62 candidate lapatinib resistance genes. We validated the top ranking genes, i.e., PIK3CA and PIK3CB, by showing that their forced expression confers resistance to lapatinib in vitro and found that their mutation/overexpression is associated to poor prognosis in human breast tumors. Then, we successfully applied this approach to the identification of erlotinib resistance genes in pancreatic cancer, thus showing the intrinsic versatility of the approach. The acquired knowledge can help identifying combinations of targeted drugs to overcome the occurrence of resistance, thus opening new horizons for more effective treatment of tumors.
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy; Current address: Experimental Cancer Genetics, The Wellcome Trust Sanger Institute, Cambridge, UK.
authors.forename: Marco
authors.initials: M
authors.lastname: Ranzani
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy; Current address: Division of Molecular Pathology, The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: Stefano
authors.initials: S
authors.lastname: Annunziato
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Calabria
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Brasca
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Benedicenti
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy.
authors.forename: Pierangela
authors.initials: P
authors.lastname: Gallina
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy; Vita Salute San Raffaele University, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Naldini
authors.affiliation: San Raffaele Telethon Institute for Gene Therapy, San Raffaele Scientific Institute, Milan, Italy. Electronic address: montini.eugenio@hsr.it.
authors.forename: Eugenio
authors.initials: E
authors.lastname: Montini
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics*; D045744:Cell Line, Tumor; D058534:Class I Phosphatidylinositol 3-Kinases; D019008:Drug Resistance, Neoplasm; D000069347:Erlotinib Hydrochloride; D005260:Female; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D000077341:Lapatinib; D016086:Lentivirus / Q000235:genetics; D058990:Molecular Targeted Therapy; D016254:Mutagenesis, Insertional / Q000379:methods*; D010190:Pancreatic Neoplasms / Q000235:genetics*; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics; D011379:Prognosis; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D011799:Quinazolines / Q000494:pharmacology*
chemical_list: D047428:Protein Kinase Inhibitors; D011799:Quinazolines; D000077341:Lapatinib; D000069347:Erlotinib Hydrochloride; D019869:Phosphatidylinositol 3-Kinases; D058534:Class I Phosphatidylinositol 3-Kinases; C484760:PIK3CA protein, human; C497132:PIK3CB protein, human