title: TALEN mediated targeted editing of GM2/GD2-synthase gene modulates anchorage independent growth by reducing anoikis resistance in mouse tumor cells.
abstract: Complex ganglioside expression is highly deregulated in several tumors which is further dependent on specific ganglioside synthase genes. Here, we designed and constructed a pair of highly specific transcription-activator like effector endonuclease (TALENs) to disrupt a particular genomic locus of mouse GM2-synthase, a region conserved in coding sequence of all four transcript variants of mouse GM2-synthase. Our designed TALENs effectively work in different mouse cell lines and TALEN induced mutation rate is over 45%. Clonal selection strategy is undertaken to generate stable GM2-synthase knockout cell line. We have also demonstrated non-homologous end joining (NHEJ) mediated integration of neomycin cassette into the TALEN targeted GM2-synthase locus. Functionally, clonally selected GM2-synthase knockout clones show reduced anchorage-independent growth (AIG), reduction in tumor growth and higher cellular adhesion as compared to wild type Renca-v cells. Insight into the mechanism shows that, reduced AIG is due to loss in anoikis resistance, as both knockout clones show increased sensitivity to detachment induced apoptosis. Therefore, TALEN mediated precise genome editing at GM2-synthase locus not only helps us in understanding the function of GM2-synthase gene and complex gangliosides in tumorigenicity but also holds tremendous potential to use TALENs in translational cancer research and therapeutics.
authors.affiliation: Division of Molecular Medicine, Bose Institute, Kolkata, India.
authors.forename: Barun
authors.initials: B
authors.lastname: Mahata
authors.affiliation: Division of Molecular Medicine, Bose Institute, Kolkata, India.
authors.forename: Avisek
authors.initials: A
authors.lastname: Banerjee
authors.affiliation: Division of Molecular Medicine, Bose Institute, Kolkata, India.
authors.forename: Manjari
authors.initials: M
authors.lastname: Kundu
authors.affiliation: Department of Infectious Diseases and Immunology, CSIR-Indian Institute of Chemical Biology, Kolkata, India.
authors.forename: Uday
authors.initials: U
authors.lastname: Bandyopadhyay
authors.affiliation: Division of Molecular Medicine, Bose Institute, Kolkata, India.
authors.forename: Kaushik
authors.initials: K
authors.lastname: Biswas
mesh_terms: D000818:Animals; D023102:Anoikis / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites; D002448:Cell Adhesion / Q000235:genetics; D045744:Cell Line, Tumor; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D059766:DNA End-Joining Repair; D004720:Endonucleases / Q000235:genetics* / Q000378:metabolism*; D015870:Gene Expression; D055786:Gene Knockout Techniques; D018390:Gene Targeting; D051379:Mice; D017350:N-Acetylgalactosaminyltransferases / Q000737:chemistry / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D011485:Protein Binding; D047368:Tumor Burden
chemical_list: D017350:N-Acetylgalactosaminyltransferases; C023220:(N-acetylneuraminyl)-galactosylglucosylceramide N-acetylgalactosaminyltransferase; D004720:Endonucleases