HOTAIR Long Noncoding RNA Promotes Gastric Cancer Metastasis through Suppression of Poly r(C)-Binding Protein (PCBP) 1

The objective of this study was to evaluate the role of HOTAIR long noncoding RNA in gastric cancer metastasis. We analyzed HOTAIR expression levels by real-time reverse transcription PCR and Northern blot analysis in 100 gastric tissues (50 gastric cancer tissues and 50 adjacent normal mucosa), and in four gastric cancer cell lines. Transient RNAi-mediated knockdown and pcDNA-mediated overexpression of HOTAIR were performed. Stable shRNA-mediated knockdown and lentiviral-mediated overexpression of HOTAIR were to study the role of HOTAIR on in vivo tumorigenicity and metastatic burden in the context of xenograft assays. Proteomic profiling was performed to decipher differential protein expression in cells with different HOTAIR expression levels. One of the differentially regulated proteins, Poly r(C)-binding protein (PCBP) 1, was subsequently validated and its function evaluated through xenograft assays. Expression of HOTAIR was significantly higher in cancerous tissues than in adjacent normal mucosa. HOTAIR expression levels dictated in vitro and in vivo tumorigenicity and metastatic potential in these cells. PCBP1 and HOTAIR have an inverse relationship, both at expression level and in function. A direct interaction between the two was confirmed through RNA immunoprecipitation coupled with quantitative real-time PCR. PCBP1 was confirmed to be an inhibitor of gastric cancer pathogenesis and as functionally opposite to HOTAIR long noncoding RNA. In conclusion, HOTAIR expression may serve as a potentially important disease biomarker for the identification of high-risk gastric cancer patients. Moreover, our findings provide mechanistic evidence for HOTAIR overexpression and PCBP1 downregulation and the ensuing malignant phenotype in both cultured and xenograft gastric cancer cells. Mol Cancer Ther; 14(5); 1162–70. ©2015 AACR.

[1]  S. Miyano,et al.  Long noncoding RNA HOTAIR regulates polycomb-dependent chromatin modification and is associated with poor prognosis in colorectal cancers. , 2011, Cancer research.

[2]  J. Mattick.  Non‐coding RNAs: the architects of eukaryotic complexity , 2001, EMBO reports.

[3]  J. Rinn,et al.  Many human large intergenic noncoding RNAs associate with chromatin-modifying complexes and affect gene expression , 2009, Proceedings of the National Academy of Sciences.

[4]  Olivier Voinnet,et al.  The long and the short of noncoding RNAs. , 2009, Current opinion in cell biology.

[5]  Zhong Liu,et al.  Long non-coding RNA expression profile in human gastric cancer and its clinical significances , 2013, Journal of Translational Medicine.

[6]  J. Rinn,et al.  Major molecular differences between mammalian sexes are involved in drug metabolism and renal function. , 2004, Developmental cell.

[7]  M. Emadi-Baygi,et al.  Association of HOTAIR expression in gastric carcinoma with invasion and distant metastasis , 2014, Advanced biomedical research.

[8]  J. Rinn,et al.  lincRNAs act in the circuitry controlling pluripotency and differentiation , 2011, Nature.

[9]  G. Hussey,et al.  Transforming Growth Factor-β (TGFβ)-mediated Phosphorylation of hnRNP E1 Induces EMT via Transcript Selective Translational Induction of Dab2 and ILEI , 2010, Nature cell biology.

[10]  J. Rinn,et al.  Scaffold function of long non-coding RNA HOTAIR in protein ubiquitination , 2013, Nature Communications.

[11]  A. Iacoangeli,et al.  BC200 RNA in invasive and preinvasive breast cancer. , 2004, Carcinogenesis.

[12]  Sang Kil Lee,et al.  Long non-coding RNA HOTAIR promotes carcinogenesis and invasion of gastric adenocarcinoma. , 2014, Biochemical and biophysical research communications.

[13]  Gregory J. Hannon,et al.  Small RNAs as Guardians of the Genome , 2009, Cell.

[14]  J. Li,et al.  PCBP1 suppresses the translation of metastasis-associated PRL-3 phosphatase. , 2010, Cancer cell.

[15]  Howard Y. Chang,et al.  Long noncoding RNA HOTAIR reprograms chromatin state to promote cancer metastasis , 2010, Nature.

[16]  Ming Sun,et al.  Lnc RNA HOTAIR functions as a competing endogenous RNA to regulate HER2 expression by sponging miR-331-3p in gastric cancer , 2014, Molecular Cancer.

[17]  Ying-qiang Shi,et al.  The role of surgery in the treatment of gastric cancer , 2010, Journal of surgical oncology.

[18]  D. Moazed.  Small RNAs in transcriptional gene silencing and genome defence , 2009, Nature.

[19]  W. Isaacs,et al.  DD3: a new prostate-specific gene, highly overexpressed in prostate cancer. , 1999, Cancer research.

[20]  Wei Zhang,et al.  Elevated expression of PCGEM1, a prostate-specific gene with cell growth-promoting function, is associated with high-risk prostate cancer patients , 2004, Oncogene.

[21]  J. Rinn,et al.  Large non-coding RNAs: missing links in cancer? , 2010, Human molecular genetics.

[22]  M. Augustus,et al.  PCGEM1, a prostate-specific gene, is overexpressed in prostate cancer. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[23]  Andrew S Brown,et al.  Establishment of a TGFβ-Induced Post-Transcriptional EMT Gene Signature , 2012, PloS one.

[24]  B. Xiao,et al.  Differential expression of microRNA species in human gastric cancer versus non‐tumorous tissues , 2009, Journal of gastroenterology and hepatology.

[25]  David I. Smith,et al.  Long, abundantly expressed non-coding transcripts are altered in cancer. , 2008, Human molecular genetics.

[26]  P. Howe,et al.  Identification of an mRNP complex regulating tumorigenesis at the translational elongation step. , 2011, Molecular cell.

[27]  E. Cantrell.  Lymph nodes and gastric cancer. , 1971, British medical journal.