title: Pleckstrin homology domain-containing protein PHLDB3 supports cancer growth via a negative feedback loop involving p53.
abstract: The tumour suppressor p53 transactivates the expression of its target genes to exert its functions. Here, we identify a pleckstrin homology domain-containing protein (PHLDB3)-encoding gene as a p53 target. PHLDB3 overexpression increases proliferation and restrains apoptosis of wild-type p53-harboring cancer cells by reducing p53 protein levels. PHLDB3 binds to MDM2 (mouse double minute 2 homolog) and facilitates MDM2-mediated ubiquitination and degradation of p53. Knockdown of PHLDB3 more efficiently inhibits the growth of mouse xenograft tumours derived from human colon cancer HCT116 cells that contain wild type p53 compared with p53-deficient HCT116 cells, and also sensitizes tumour cells to doxorubicin and 5-Fluorouracil. Analysis of cancer genomic databases reveals that PHLDB3 is amplified and/or highly expressed in numerous human cancers. Altogether, these results demonstrate that PHLDB3 promotes tumour growth by inactivating p53 in a negative feedback fashion and suggest PHLDB3 as a potential therapeutic target in various human cancers.
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Department of Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Tengfei
authors.initials: T
authors.lastname: Chao
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Xiang
authors.initials: X
authors.lastname: Zhou
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Bo
authors.identifier: 0000-0002-4933-6424
authors.initials: B
authors.lastname: Cao
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Peng
authors.initials: P
authors.lastname: Liao
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Hongbing
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Hee-Won
authors.initials: HW
authors.lastname: Park
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Shelya X
authors.initials: SX
authors.lastname: Zeng
authors.affiliation: Department of Biochemistry &Molecular Biology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.|Tulane Cancer Center, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Lu
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects / Q000235:genetics; D001483:Base Sequence; D049109:Cell Proliferation / Q000187:drug effects; D025461:Feedback, Physiological / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D055785:Gene Knockdown Techniques; D045325:HCT116 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation / Q000235:genetics; D009363:Neoplasm Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000235:genetics / Q000473:pathology*; D000070539:Pleckstrin Homology Domains; D011485:Protein Binding / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D054875:Ubiquitination / Q000187:drug effects
chemical_list: D000970:Antineoplastic Agents; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; C000628219:PHLDB3 protein, human; D016159:Tumor Suppressor Protein p53; D051736:Proto-Oncogene Proteins c-mdm2