Overexpression of Snail induces epithelial–mesenchymal transition and a cancer stem cell–like phenotype in human colorectal cancer cells

Epithelial–mesenchymal transition (EMT) is a critical process providing tumor cells with the ability to migrate and escape from the primary tumor and metastasize to distant sites. Recently, EMT was shown to be associated with the cancer stem cell (CSC) phenotype in breast cancer. Snail is a transcription factor that mediates EMT in a number of tumor types, including colorectal cancer (CRC). Our study was done to determine the role of Snail in mediating EMT and CSC function in CRC. Human CRC specimens were stained for Snail expression, and human CRC cell lines were transduced with a retroviral Snail construct or vector control. Cell proliferation and chemosensitivity to oxaliplatin of the infected cells were determined by the MTT (colorimetric 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay. Migration and invasion were determined in vitro using modified Boyden chamber assays. EMT and putative CSC markers were analyzed using Western blotting. Intravenous injection of tumor cells was done to evaluate their metastatic potential in mice. Snail was overexpressed in human CRC surgical specimens. This overexpression induced EMT and a CSC‐like phenotype in human CRC cells and enhanced cell migration and invasion (P < 0.002 vs. control). Snail overexpression also led to an increase in metastasis formation in vivo (P < 0.002 vs. control). Furthermore, the Snail‐overexpressing CRC cells were more chemoresistant to oxaliplatin than control cells. Increased Snail expression induces EMT and the CSC‐like phenotype in CRC cells, which enhance cancer cell invasion and chemoresistance. Thus, Snail is a potential therapeutic target in metastatic CRC.

[1]  B. Obrink,et al.  Cell-cell contacts mediated by E-cadherin (uvomorulin) restrict invasive behavior of L-cells , 1991, The Journal of cell biology.

[2]  S. Weiss,et al.  A multipotent EGF-responsive striatal embryonic progenitor cell produces neurons and astrocytes , 1992, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[3]  W. Bodmer,et al.  Mutated epithelial cadherin is associated with increased tumorigenicity and loss of adhesion and of responsiveness to the motogenic trefoil factor 2 in colon carcinoma cells. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[4]  A. G. Herreros,et al.  The transcription factor Snail is a repressor of E-cadherin gene expression in epithelial tumour cells , 2000, Nature Cell Biology.

[5]  W. Bodmer,et al.  Hypermethylation of the promoter region of the E-cadherin gene (CDH1) in sporadic and ulcerative colitis associated colorectal cancer , 2001, Gut.

[6]  Birgit Luber,et al.  Differential expression of the epithelial-mesenchymal transition regulators snail, SIP1, and twist in gastric cancer. , 2002, The American journal of pathology.

[7]  M. Nieto,et al.  The snail superfamily of zinc-finger transcription factors , 2002, Nature Reviews Molecular Cell Biology.

[8]  S. Ramaswamy,et al.  Twist, a Master Regulator of Morphogenesis, Plays an Essential Role in Tumor Metastasis , 2004, Cell.

[9]  M. Hung,et al.  Dual regulation of Snail by GSK-3β-mediated phosphorylation in control of epithelial–mesenchymal transition , 2004, Nature Cell Biology.

[10]  Robert D Cardiff,et al.  The transcriptional repressor Snail promotes mammary tumor recurrence. , 2005, Cancer cell.

[11]  K. Miyazaki,et al.  Snail accelerates cancer invasion by upregulating MMP expression and is associated with poor prognosis of hepatocellular carcinoma , 2005, British Journal of Cancer.

[12]  Michael Dean,et al.  Tumour stem cells and drug resistance , 2005, Nature Reviews Cancer.

[13]  T. Smyrk,et al.  The Transcriptional Repressor SNAIL Is Overexpressed in Human Colon Cancer , 2005, Digestive Diseases and Sciences.

[14]  J. Nesland,et al.  Snail, Slug, and Smad‐interacting protein 1 as novel parameters of disease aggressiveness in metastatic ovarian and breast carcinoma , 2005, Cancer.

[15]  L. Ellis,et al.  Chronic Oxaliplatin Resistance Induces Epithelial-to-Mesenchymal Transition in Colorectal Cancer Cell Lines , 2006, Clinical Cancer Research.

[16]  J. Thiery,et al.  Complex networks orchestrate epithelial–mesenchymal transitions , 2006, Nature Reviews Molecular Cell Biology.

[17]  M. Diehn,et al.  Cancer stem cells and radiotherapy: new insights into tumor radioresistance. , 2006, Journal of the National Cancer Institute.

[18]  Mark W. Dewhirst,et al.  Glioma stem cells promote radioresistance by preferential activation of the DNA damage response , 2006, Nature.

[19]  M. Raaijmakers,et al.  Preferential expression of a high number of ATP binding cassette transporters in both normal and leukemic CD34+CD38− cells , 2006, Leukemia.

[20]  C. Theillet,et al.  Snail and Slug Play Distinct Roles during Breast Carcinoma Progression , 2006, Clinical Cancer Research.

[21]  Anne E Carpenter,et al.  The Spemann organizer gene, Goosecoid, promotes tumor metastasis , 2006, Proceedings of the National Academy of Sciences.

[22]  H. Kajiyama,et al.  Chemoresistance to paclitaxel induces epithelial-mesenchymal transition and enhances metastatic potential for epithelial ovarian carcinoma cells. , 2007, International journal of oncology.

[23]  Héctor Peinado,et al.  Snail, Zeb and bHLH factors in tumour progression: an alliance against the epithelial phenotype? , 2007, Nature Reviews Cancer.

[24]  M. Todaro,et al.  Colon cancer stem cells dictate tumor growth and resist cell death by production of interleukin-4. , 2007, Cell stem cell.

[25]  G. Z. Cheng,et al.  Twist transcriptionally up-regulates AKT2 in breast cancer cells leading to increased migration, invasion, and resistance to paclitaxel. , 2007, Cancer research.

[26]  X. Guan,et al.  CD133+ HCC cancer stem cells confer chemoresistance by preferential expression of the Akt/PKB survival pathway , 2008, Oncogene.

[27]  L. Ellis,et al.  Neuropilin-2–Mediated Tumor Growth and Angiogenesis in Pancreatic Adenocarcinoma , 2008, Clinical Cancer Research.

[28]  Wenjun Guo,et al.  The Epithelial-Mesenchymal Transition Generates Cells with Properties of Stem Cells , 2008, Cell.

[29]  A. Puisieux,et al.  Generation of Breast Cancer Stem Cells through Epithelial-Mesenchymal Transition , 2008, PloS one.

[30]  Eric S. Lander,et al.  Identification of Selective Inhibitors of Cancer Stem Cells by High-Throughput Screening , 2009, Cell.

[31]  R. Huang,et al.  Epithelial-Mesenchymal Transitions in Development and Disease , 2009, Cell.

[32]  H. Ford,et al.  Six1 expands the mouse mammary epithelial stem/progenitor cell pool and induces mammary tumors that undergo epithelial-mesenchymal transition. , 2009, The Journal of clinical investigation.

[33]  Raghu Kalluri,et al.  The basics of epithelial-mesenchymal transition. , 2009, The Journal of clinical investigation.

[34]  A. Ghanate,et al.  Snail and Slug Mediate Radioresistance and Chemoresistance by Antagonizing p53‐Mediated Apoptosis and Acquiring a Stem‐Like Phenotype in Ovarian Cancer Cells , 2009, Stem cells.

[35]  Yi-Wei Chen,et al.  Aldehyde dehydrogenase 1 is a putative marker for cancer stem cells in head and neck squamous cancer. , 2009, Biochemical and biophysical research communications.

[36]  Jose M. Silva,et al.  SNAI1 expression in colon cancer related with CDH1 and VDR downregulation in normal adjacent tissue , 2009, Oncogene.

[37]  M. Todaro,et al.  Aurora-a is essential for the tumorigenic capacity and chemoresistance of colorectal cancer stem cells. , 2010, Cancer research.

[38]  G Spagnoli,et al.  Prognostic impact of the expression of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and ALDH1 in colorectal cancer , 2010, British Journal of Cancer.

[39]  S. Agarwal,et al.  In situ identification of putative cancer stem cells by multiplexing ALDH1, CD44, and cytokeratin identifies breast cancer patients with poor prognosis. , 2010, The American journal of pathology.

[40]  Shih-Hwa Chiou,et al.  SNAIL regulates interleukin-8 expression, stem cell-like activity, and tumorigenicity of human colorectal carcinoma cells. , 2011, Gastroenterology.

[41]  L. Ellis,et al.  Chronic exposure of colorectal cancer cells to bevacizumab promotes compensatory pathways that mediate tumour cell migration , 2011, British Journal of Cancer.