title: Cancer driver candidate genes AVL9, DENND5A and NUPL1 contribute to MDCK cystogenesis.
abstract: AVL9, DENND5A and NUPL1 are among the cancer driver candidate genes previously identified via dog-human comparison, and may function in epithelial cell polarity as indicated by bioinformatics analysis. To better understand their cellular functions and roles in cancer, we knocked down each gene in MDCKII cells through shRNA and performed three-dimensional culture. Compared to the control, the knockdown clones developed significantly more abnormal cysts, e.g., cysts with the lumen harboring dead and/or live cells, or cysts having multiple lumens. Further analysis revealed that abnormalities initiated at the first cell division and persisted throughout the entire cystogenesis process. For NUPL1-knockdown cells, abnormal cytogenesis largely arose from faulty cell divisions, notably monopolar spindles or spindles with poorly separated poles. For AVL9- or DENND5A-knockdown cells, abnormalities originated from both aberrant intracellular trafficking and defective mitosis. Moreover, while all knockdown clones displayed an accelerated rate of both cell proliferation and death, only AVL9- and DENND5A-knockdowns, but not NUPL1-knockdown, promoted cell migration. These observations indicate that NUPL1 contributes to bipolar spindle formation, whereas AVL9 and DENND5A participate in both intracellular trafficking and cell cycle progression. Our study shed lights on these genes' normal cellular functions and on how their alteration contributes to carcinogenesis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.|Current Address: Human Oncology & Pathogenesis Program, Memorial Sloan-Kettering Cancer Center, New York.
authors.forename: Jianing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.
authors.forename: Huan
authors.initials: H
authors.lastname: Xiong
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.
authors.forename: Zhongyao
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Genetics & Genome Sciences and Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, Ohio.
authors.forename: Zhenghe
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Department of Cellular Biology, University of Georgia, Athens.
authors.forename: Edward T
authors.initials: ET
authors.lastname: Kipreos
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.
authors.forename: Stephen
authors.initials: S
authors.lastname: Dalton
authors.affiliation: Department of Biochemistry and Molecular Biology, Institute of Bioinformatics, University of Georgia, Athens.
authors.forename: Shaying
authors.initials: S
authors.lastname: Zhao
keywords: AVL9; Apicobasal Polarity; Cytogenesis; DENND5A; MDCK; NUPL1