title: The p53 Target Gene SIVA Enables Non-Small Cell Lung Cancer Development.
abstract: Although p53 transcriptional activation potential is critical for its ability to suppress cancer, the specific target genes involved in tumor suppression remain unclear. SIVA is a p53 target gene essential for p53-dependent apoptosis, although it can also promote proliferation through inhibition of p53 in some settings. Thus, the role of SIVA in tumorigenesis remains unclear. Here, we seek to define the contribution of SIVA to tumorigenesis by generating Siva conditional knockout mice. Surprisingly, we find that SIVA loss inhibits non-small cell lung cancer (NSCLC) development, suggesting that SIVA facilitates tumorigenesis. Similarly, SIVA knockdown in mouse and human NSCLC cell lines decreases proliferation and transformation. Consistent with this protumorigenic role for SIVA, high-level SIVA expression correlates with reduced NSCLC patient survival. SIVA acts independently of p53 and, instead, stimulates mTOR signaling and metabolism in NSCLC cells. Thus, SIVA enables tumorigenesis in a p53-independent manner, revealing a potential new cancer therapy target.
  
  
  CONCLUSIONS
  These findings collectively reveal a novel role for the p53 target gene SIVA both in regulating metabolism and in enabling tumorigenesis, independently of p53. Importantly, these studies further identify SIVA as a new prognostic marker and as a potential target for NSCLC cancer therapy.
authors: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
authors: Jeanine L
authors: JL
authors: Van Nostrand
authors: Department of Biology, Ecole Normale Supérieure de Lyon, Lyon, France.
authors: Alice
authors: A
authors: Brisac
authors: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
authors: Stephano S
authors: SS
authors: Mello
authors: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
authors: Suzanne B R
authors: SB
authors: Jacobs
authors: Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California.
authors: Richard
authors: R
authors: Luong
authors: Division of Radiation and Cancer Biology, Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California. Department of Genetics, Stanford University School of Medicine, Stanford, California. attardi@stanford.edu.
authors: Laura D
authors: LD
authors: Attardi
mesh_terms: D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000235:genetics*; D001343:Autophagy / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D004195:Disease Models, Animal; D004734:Energy Metabolism / Q000235:genetics; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D023061:Gene Order; D018390:Gene Targeting; D056426:Genetic Loci; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics; D058570:TOR Serine-Threonine Kinases / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
chemical_list: D051017:Apoptosis Regulatory Proteins; C117307:KRAS protein, human; C106549:SIVA1 protein, human; D016159:Tumor Suppressor Protein p53; D058570:TOR Serine-Threonine Kinases; D016283:Proto-Oncogene Proteins p21(ras)