Overexpression of paxillin induced by miR-137 suppression promotes tumor progression and metastasis in colorectal cancer

The deregulation of paxillin (PXN) has been involved in the progression and metastasis of different malignancies including colorectal cancer (CRC). miR-137 is frequently suppressed in CRC. PXN is predicted to be a direct target of miR-137 in CRC cells. On this basis, we hypothesized that overexpression of PXN induced by suppression of miR-137 may promote tumor progression and metastasis and predicts poor prognosis. We detected the expression of PXN and miR-137 in clinical tumor tissues by immunohistochemical analysis and real-time PCR, positive PXN staining was observed in 198 of the 247 (80.1%) cases, whereas no or weak PXN staining was observed in the adjacent non-cancerous area. Higher level of PXN messenger RNA (mRNA) and lower level of miR-137 was observed in cancer tissues than adjacent non-cancerous tissues. High expression of PXN and low expression of miR-137 was associated with aggressive tumor phenotype and adverse prognosis. Moreover, the expression of PXN was negatively correlated with miR-137 expression. A dual-luciferase reporter gene assay validated that PXN was a direct target of miR-137. The use of miR-137 mimics or inhibitor could decrease or increase PXN mRNA and protein levels in CRC cell lines. Knockdown of PXN or ectopic expression of miR-137 could markedly inhibit cell proliferation, migration and invasion in vitro and repress tumor growth and metastasis in vivo. Taken together, these results demonstrated that overexpression of PXN induced by suppression of miR-137 promotes tumor progression and metastasis and could serve as an independent prognostic indicator in CRC patients.

[1]  S. Shi,et al.  Increased Expression of Paxillin is Found in Human Oesophageal Squamous Cell Carcinoma: A Tissue Microarray Study , 2008, The Journal of international medical research.

[2]  H. Horvitz,et al.  MicroRNA expression profiles classify human cancers , 2005, Nature.

[3]  F. He,et al.  MiR-137 Targets Estrogen-Related Receptor Alpha and Impairs the Proliferative and Migratory Capacity of Breast Cancer Cells , 2012, PloS one.

[4]  Scott M Langevin,et al.  MicroRNA-137 promoter methylation in oral rinses from patients with squamous cell carcinoma of the head and neck is associated with gender and body mass index. , 2010, Carcinogenesis.

[5]  Phillip D. Zamore,et al.  Ribo-gnome: The Big World of Small RNAs , 2005, Science.

[6]  Zhiwei Wang,et al.  Effects of paxillin on HCT-8 human colorectal cancer cells. , 2011, Hepato-gastroenterology.

[7]  G. Raj,et al.  Paxillin Regulates Androgen- and Epidermal Growth Factor-induced MAPK Signaling and Cell Proliferation in Prostate Cancer Cells* , 2010, The Journal of Biological Chemistry.

[8]  M. Guo,et al.  Epigenetic changes in colorectal cancer , 2013, Chinese journal of cancer.

[9]  S. Robinson,et al.  MicroRNA-137 targets microphthalmia-associated transcription factor in melanoma cell lines. , 2008, Cancer research.

[10]  C. Turner.  Paxillin and focal adhesion signalling , 2000, Nature Cell Biology.

[11]  George A. Calin,et al.  MicroRNAs — the micro steering wheel of tumour metastases , 2009, Nature Reviews Cancer.

[12]  T. Jiang,et al.  miR-137 is frequently down-regulated in glioblastoma and is a negative regulator of Cox-2. , 2012, European journal of cancer.

[13]  M. Tainsky,et al.  Loss of AP‐2 results in downregulation of c‐KIT and enhancement of melanoma tumorigenicity and metastasis , 1998, The EMBO journal.

[14]  A. Jemal,et al.  Cancer Statistics, 2010 , 2010, CA: a cancer journal for clinicians.

[15]  Hsin-Yi Chen,et al.  Brk Activates Rac1 and Promotes Cell Migration and Invasion by Phosphorylating Paxillin , 2004, Molecular and Cellular Biology.

[16]  Ming Fang,et al.  Paxillin expression levels are correlated with clinical stage and metastasis in salivary adenoid cystic carcinoma. , 2010, Journal of oral pathology & medicine : official publication of the International Association of Oral Pathologists and the American Academy of Oral Pathology.

[17]  C. Turner,et al.  Paxillin: adapting to change. , 2004, Physiological reviews.

[18]  M. Basson,et al.  Pressure activates colon cancer cell adhesion via paxillin phosphorylation, Crk, Cas, and Rac1 , 2008, Cellular and Molecular Life Sciences.

[19]  George P Cobb,et al.  microRNAs as oncogenes and tumor suppressors. , 2007, Developmental biology.

[20]  D. DeFranco,et al.  The Group 3 LIM domain protein paxillin potentiates androgen receptor transactivation in prostate cancer cell lines. , 2003, Cancer research.

[21]  Yu-hong Li,et al.  DNA polymeraseη protein expression predicts treatment response and survival of metastatic gastric adenocarcinoma patients treated with oxaliplatin-based chemotherapy , 2010, Journal of Translational Medicine.

[22]  D. Xie,et al.  Clinicopathological significance of expression of paxillin, syndecan-1 and EMMPRIN in hepatocellular carcinoma. , 2005, World journal of gastroenterology.

[23]  K. Murakami,et al.  Transcription factor recognition surface on the RNA polymerase alpha subunit is involved in contact with the DNA enhancer element. , 1996, The EMBO journal.

[24]  Michael D Schaller,et al.  Paxillin: a focal adhesion-associated adaptor protein , 2001, Oncogene.

[25]  C. Croce,et al.  MicroRNA signatures in human cancers , 2006, Nature Reviews Cancer.

[26]  C. Boland,et al.  Epigenetic silencing of miR-137 is an early event in colorectal carcinogenesis. , 2010, Cancer research.

[27]  M. Malumbres,et al.  Control of cell proliferation pathways by microRNAs , 2008, Cell cycle.

[28]  M. Tatsuta,et al.  Reduced expression of focal adhesion kinase in liver metastases compared with matched primary human colorectal adenocarcinomas. , 2001, Clinical cancer research : an official journal of the American Association for Cancer Research.

[29]  C. Croce,et al.  A microRNA expression signature of human solid tumors defines cancer gene targets , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[30]  J. Inazawa,et al.  Exploration of tumor-suppressive microRNAs silenced by DNA hypermethylation in oral cancer. , 2008, Cancer research.

[31]  Ya‐Wen Cheng,et al.  Paxillin predicts survival and relapse in non-small cell lung cancer by microRNA-218 targeting. , 2010, Cancer research.

[32]  Anupama E. Gururaj,et al.  p21-activated kinases in cancer , 2006, Nature Reviews Cancer.

[33]  Chang-Zheng Chen,et al.  MicroRNAs as oncogenes and tumor suppressors. , 2005, The New England journal of medicine.

[34]  Anton J. Enright,et al.  Human MicroRNA Targets , 2004, PLoS biology.

[35]  E. Schaefer,et al.  Multiple stimuli induce tyrosine phosphorylation of the Crk-binding sites of paxillin. , 2001, The Biochemical journal.

[36]  T. S. Panetti,et al.  Tyrosine phosphorylation of paxillin, FAK, and p130CAS: effects on cell spreading and migration. , 2002, Frontiers in bioscience : a journal and virtual library.

[37]  C. Burge,et al.  Prediction of Mammalian MicroRNA Targets , 2003, Cell.

[38]  D. Bartel.  MicroRNAs Genomics, Biogenesis, Mechanism, and Function , 2004, Cell.

[39]  K. Gunsalus,et al.  Combinatorial microRNA target predictions , 2005, Nature Genetics.

[40]  N. Dubrawsky.  Cancer statistics , 1989, CA: a cancer journal for clinicians.

[41]  L. Ellis,et al.  APOBEC3G promotes liver metastasis in an orthotopic mouse model of colorectal cancer and predicts human hepatic metastasis. , 2011, The Journal of clinical investigation.

[42]  A. Leibovitz,et al.  Classification of human colorectal adenocarcinoma cell lines. , 1976, Cancer research.

[43]  R. Pillai.  MicroRNA function: multiple mechanisms for a tiny RNA? , 2005, RNA.

[44]  Y. Kudo,et al.  Invasion and Metastasis of Oral Cancer Cells Require Methylation of E-Cadherin and/or Degradation of Membranous β-Catenin , 2004, Clinical Cancer Research.

[45]  F. Slack,et al.  Oncomirs — microRNAs with a role in cancer , 2006, Nature Reviews Cancer.

[46]  X. Chen,et al.  miR‐137 targets Cdc42 expression, induces cell cycle G1 arrest and inhibits invasion in colorectal cancer cells , 2011, International journal of cancer.

[47]  William Ignace Wei,et al.  Mature miR-184 as Potential Oncogenic microRNA of Squamous Cell Carcinoma of Tongue , 2008, Clinical Cancer Research.

[48]  A. Sparks,et al.  The Genomic Landscapes of Human Breast and Colorectal Cancers , 2007, Science.

[49]  A. Moscona.  Squamous metaplasia and keratinization of chorionic epithelium of the chick embryo in egg and in culture , 1959 .

[50]  R. Salgia,et al.  Paxillin expression and amplification in early lung lesions of high-risk patients, lung adenocarcinoma and metastatic disease , 2010, Journal of Clinical Pathology.