Urothelial carcinoma associated 1 is a hypoxia-inducible factor-1α-targeted long noncoding RNA that enhances hypoxic bladder cancer cell proliferation, migration, and invasion

Urothelial carcinoma associated 1 (UCA1) has been identified as an oncogenic long noncoding RNA (lncRNA) that is involved in bladder cancer progression and acts as a diagnostic biomarker for bladder carcinoma. Here, we studied the expression and function of lncRNA-UCA1 in the hypoxic microenvironment of bladder cancer. The expression and transcriptional activity of lncRNA-UCA1 were measured by quantitative real-time polymerase chain reaction and luciferase assays. Cell proliferation and apoptosis were evaluated by MTT assays and flow cytometry. Cell migration and invasion were detected by wound healing, migration, and invasion assays. The binding of hypoxia-inducible factor-1α (HIF-1α) to hypoxia response elements (HREs) in the lncRNA-UCA1 promoter was confirmed by electrophoretic mobility shift assay and chromatin immunoprecipitation. HRE mutations were generated by using a site-directed mutagenesis kit, and HIF-1α knockdown was mediated by small interfering RNA. The effect of HIF-1α inhibition by YC-1 on lncRNA-UCA1 expression was also examined. LncRNA-UCA1 was upregulated by hypoxia in bladder cancer cells. Under hypoxic conditions, lncRNA-UCA1 upregulation increased cell proliferation, migration, and invasion and inhibited apoptosis. The underlying mechanism of hypoxia-upregulated lncRNA-UCA1 expression was that HIF-1α specifically bound to HREs in the lncRNA-UCA1 promoter. Furthermore, HIF-1α knockdown or inhibition could prevent lncRNA-UCA1 upregulation under hypoxia. These findings revealed the mechanism of lncRNA-UCA1 upregulation in hypoxic bladder cancer cells and suggested that effective blocking of lncRNA-UCA1 expression in the hypoxic microenvironment of bladder cancer could be a novel therapeutic strategy.

[1]  G. Song,et al.  Role of hypoxia in the hallmarks of human cancer , 2009, Journal of cellular biochemistry.

[2]  G. Semenza,et al.  HIF-1, O2, and the 3 PHDs How Animal Cells Signal Hypoxia to the Nucleus , 2001, Cell.

[3]  Xing Chen,et al.  LncRNADisease: a database for long-non-coding RNA-associated diseases , 2012, Nucleic Acids Res..

[4]  Chen Yang,et al.  Long non-coding RNA UCA1 regulated cell cycle distribution via CREB through PI3-K dependent pathway in bladder carcinoma cells. , 2012, Gene.

[5]  T. Derrien,et al.  Long Noncoding RNAs with Enhancer-like Function in Human Cells , 2010, Cell.

[6]  Thomas Werner,et al.  MatInspector and beyond: promoter analysis based on transcription factor binding sites , 2005, Bioinform..

[7]  S. Diederichs,et al.  Gutschner T , Diederichs S . The hallmarks of cancer : a long non-coding RNA point of view . RNA Biol 9 : 703-719 , 2012 .

[8]  B. Behnam,et al.  Crosstalk between breast cancer stem cells and metastatic niche: emerging molecular metastasis pathway? , 2013, Tumor Biology.

[9]  A. Lazaris,et al.  Hypoxia-inducible factor 1 alpha expression correlates with angiogenesis and unfavorable prognosis in bladder cancer. , 2004, European urology.

[10]  Guangming Lu,et al.  The complexity of bladder cancer: long noncoding RNAs are on the stage , 2013, Molecular Cancer.

[11]  Jeannie T. Lee.  Epigenetic Regulation by Long Noncoding RNAs , 2012, Science.

[12]  Xiaokun Zhao,et al.  Effects of YC-1 on Hypoxia-Inducible Factor 1 Alpha in Hypoxic Human Bladder Transitional Carcinoma Cell Line T24 Cells , 2011, Urologia Internationalis.

[13]  K. Zatloukal,et al.  Characterization of HULC, a novel gene with striking up-regulation in hepatocellular carcinoma, as noncoding RNA. , 2007, Gastroenterology.

[14]  E. Rankin,et al.  The role of hypoxia-inducible factors in tumorigenesis , 2008, Cell Death and Differentiation.

[15]  J. Montie,et al.  Bladder Cancer in 2010: How Far have We Come? , 2010, Ca.

[16]  Xu Li,et al.  UCA1, a non‐protein‐coding RNA up‐regulated in bladder carcinoma and embryo, influencing cell growth and promoting invasion , 2008, FEBS letters.

[17]  David J. Arenillas,et al.  JASPAR 2010: the greatly expanded open-access database of transcription factor binding profiles , 2009, Nucleic Acids Res..

[18]  A. Hochberg,et al.  The H19 Non-Coding RNA Is Essential for Human Tumor Growth , 2007, PloS one.

[19]  Sven Diederichs,et al.  The hallmarks of cancer , 2012, RNA biology.

[20]  Michael I. Wilson,et al.  Targeting of HIF-α to the von Hippel-Lindau Ubiquitylation Complex by O2-Regulated Prolyl Hydroxylation , 2001, Science.

[21]  C. Ching,et al.  Expanding therapeutic targets in bladder cancer: the PI3K/Akt/mTOR pathway , 2010, Laboratory Investigation.

[22]  S. Maddika,et al.  Cell survival, cell death and cell cycle pathways are interconnected: implications for cancer therapy. , 2007, Drug resistance updates : reviews and commentaries in antimicrobial and anticancer chemotherapy.

[23]  T. Chou,et al.  Magnolol suppresses hypoxia-induced angiogenesis via inhibition of HIF-1α/VEGF signaling pathway in human bladder cancer cells. , 2013, Biochemical pharmacology.

[24]  Xin-yang Wang,et al.  Roles of HIF-1α in a novel optical orthotopic spontaneous metastatic bladder cancer animal model. , 2012, Urologic oncology.

[25]  Brian Keith,et al.  Hypoxia-Inducible Factors, Stem Cells, and Cancer , 2007, Cell.

[26]  G. Semenza.  Cancer–stromal cell interactions mediated by hypoxia-inducible factors promote angiogenesis, lymphangiogenesis, and metastasis , 2013, Oncogene.

[27]  Wenjing Wu,et al.  Ets-2 Regulates Cell Apoptosis via the Akt Pathway, through the Regulation of Urothelial Cancer Associated 1, a Long Non-Coding RNA, in Bladder Cancer Cells , 2013, PloS one.

[28]  Fan Yang,et al.  Reciprocal regulation of HIF-1α and lincRNA-p21 modulates the Warburg effect. , 2014, Molecular cell.

[29]  J. Loscalzo.  The cellular response to hypoxia: tuning the system with microRNAs. , 2010, The Journal of clinical investigation.

[30]  M. Gospodarowicz.  Combination therapy: Hypoxia modification with radiotherapy for bladder cancer , 2011, Nature Reviews Clinical Oncology.

[31]  W. Wong,et al.  Hypoxia-inducible factors and the response to hypoxic stress. , 2010, Molecular cell.

[32]  Y. Allory,et al.  PI3K/AKT pathway activation in bladder carcinogenesis , 2014, International journal of cancer.

[33]  G. Semenza.  Targeting HIF-1 for cancer therapy , 2003, Nature Reviews Cancer.

[34]  A. Hochberg,et al.  The oncofetal H19 RNA connection: hypoxia, p53 and cancer. , 2010, Biochimica et biophysica acta.

[35]  G. Semenza,et al.  Hypoxia-inducible factor 1 is a basic-helix-loop-helix-PAS heterodimer regulated by cellular O2 tension. , 1995, Proceedings of the National Academy of Sciences of the United States of America.