IRX5 promotes colorectal cancer metastasis by negatively regulating the core components of the RHOA pathway.

Colorectal cancer (CRC) is one of the most common malignant tumors worldwide. As tumor metastasis is the leading cause of death in patients with CRC, it is important to elucidate the molecular mechanisms that drive CRC metastasis. Studies have shown a close relationship between Iroquois homeobox (IRX) family genes and multiple cancers, while the mechanism by which IRX5 promotes CRC metastasis is unclear. Therefore, we focused on the involvement of IRX5 in CRC metastasis. In this study, analyses of clinical data indicated that the expression of IRX5 was coincided with metastatic colorectal tumors tissues and was negatively correlated with the overall survival of patients with CRC. Functional analysis showed that IRX5 promoted the migration and invasion of CRC cells, accompanied by a large number of cellular protrusions. IRX5-overexpressing cells were more likely to form metastatic tumors in nude mice. Further analysis demonstrated that the core components of the RHOA/ROCK1/LIMK1 pathway were significantly inhibited in IRX5-overexpressing cells. Overexpression of LIMK1 effectively reversed the enhanced cellular motility caused by IRX5 overexpression. Moreover, we found that high levels of IRX5 in intestinal tissues were correlated with the inflammatory response. IRX5 was significantly increased in azoxymethane/dextran sodium sulfate intestinal tissue of mice and IRX5-overexpressing may also enhance chemokines CXCL1 and CXCL8. In summary, our findings suggested that IRX5 promoted CRC metastasis by inhibiting the RHOA-ROCK1-LIMK1 axis, which correlates with a poor prognosis.

[1]  Hualing Sun,et al.  IRX5 promotes NF‐κB signalling to increase proliferation, migration and invasion via OPN in tongue squamous cell carcinoma , 2018, Journal of cellular and molecular medicine.

[2]  Zhonghua Ma,et al.  Long noncoding RNA CRNDE promotes colorectal cancer cell proliferation via epigenetically silencing DUSP5/CDKN1A expression , 2017, Cell Death & Disease.

[3]  A. Jemal,et al.  Colorectal cancer statistics, 2017 , 2017, CA: a cancer journal for clinicians.

[4]  Keshu Xu,et al.  Downregulation of miR-377 contributes to IRX3 deregulation in hepatocellular carcinoma. , 2016, Oncology reports.

[5]  Dong Liu,et al.  Iroquois homeobox transcription factor (Irx5) promotes G1/S-phase transition in vascular smooth muscle cells by CDK2-dependent activation , 2016, American journal of physiology. Cell physiology.

[6]  L. Du,et al.  Increased expression of the long noncoding RNA CRNDE-h indicates a poor prognosis in colorectal cancer, and is positively correlated with IRX5 mRNA expression , 2016, OncoTargets and therapy.

[7]  M. Rask-Andersen,et al.  Scrutinizing the FTO locus: compelling evidence for a complex, long-range regulatory context , 2015, Human Genetics.

[8]  Jian Xu,et al.  IRX2-mediated upregulation of MMP-9 and VEGF in a PI3K/AKT-dependent manner. , 2015, Molecular medicine reports.

[9]  T. Kang,et al.  IRX1 hypomethylation promotes osteosarcoma metastasis via induction of CXCL14/NF-κB signaling. , 2015, The Journal of clinical investigation.

[10]  B. Teh,et al.  An eleven gene molecular signature for extra-capsular spread in oral squamous cell carcinoma serves as a prognosticator of outcome in patients without nodal metastases. , 2015, Oral oncology.

[11]  A. Jemal,et al.  Global cancer statistics, 2012 , 2015, CA: a cancer journal for clinicians.

[12]  Dong Liu,et al.  The Proangiogenic Effect of Iroquois Homeobox Transcription Factor Irx3 in Human Microvascular Endothelial Cells , 2014, The Journal of Biological Chemistry.

[13]  E. Batlle,et al.  Iro/IRX transcription factors negatively regulate Dpp/TGF‐β pathway activity during intestinal tumorigenesis , 2014, EMBO reports.

[14]  John M. Mariadason,et al.  RHOA inactivation enhances Wnt signaling and promotes colorectal cancer , 2014, Nature Communications.

[15]  Alexis Gautreau,et al.  Steering cell migration: lamellipodium dynamics and the regulation of directional persistence , 2014, Nature Reviews Molecular Cell Biology.

[16]  M. Hernán,et al.  Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: a randomized clinical trial. , 2014, JAMA.

[17]  Yan Wang,et al.  Knockdown of IRX2 inhibits osteosarcoma cell proliferation and invasion by the AKT/MMP9 signaling pathway. , 2014, Molecular medicine reports.

[18]  A. Jemal,et al.  Cancer treatment and survivorship statistics, 2014 , 2014, CA: a cancer journal for clinicians.

[19]  Sevan Hopyan,et al.  Formation of proximal and anterior limb skeleton requires early function of Irx3 and Irx5 and is negatively regulated by Shh signaling. , 2014, Developmental cell.

[20]  K. Mimori,et al.  Cell Cycle-Dependent Rho GTPase Activity Dynamically Regulates Cancer Cell Motility and Invasion In Vivo , 2013, PloS one.

[21]  Reiko Nishihara,et al.  Long-term colorectal-cancer incidence and mortality after lower endoscopy. , 2013, The New England journal of medicine.

[22]  A. Hoffmann,et al.  Chromatin-bound IκBα regulates a subset of polycomb target genes in differentiation and cancer. , 2013, Cancer cell.

[23]  B. Bruneau,et al.  Cooperative and antagonistic roles for Irx3 and Irx5 in cardiac morphogenesis and postnatal physiology , 2012, Development.

[24]  Z. Fu,et al.  Microcystin-LR promotes melanoma cell invasion and enhances matrix metalloproteinase-2/-9 expression mediated by NF-κB activation. , 2012, Environmental science & technology.

[25]  Yusuke Nakamura,et al.  IRX4 at 5p15 suppresses prostate cancer growth through the interaction with vitamin D receptor, conferring prostate cancer susceptibility. , 2012, Human molecular genetics.

[26]  Lawrence C. LaPointe,et al.  Colorectal Neoplasia Differentially Expressed (CRNDE), a Novel Gene with Elevated Expression in Colorectal Adenomas and Adenocarcinomas. , 2011, Genes & cancer.

[27]  C. Bezzina,et al.  Developmental aspects of cardiac arrhythmogenesis. , 2011, Cardiovascular research.

[28]  S. Adachi,et al.  Rho-kinase inhibitor upregulates migration by altering focal adhesion formation via the Akt pathway in colon cancer cells. , 2011, European journal of pharmacology.

[29]  X. Chen,et al.  Homeobox gene IRX1 is a tumor suppressor gene in gastric carcinoma , 2010, Oncogene.

[30]  M. Bertagnolli,et al.  Molecular origins of cancer: Molecular basis of colorectal cancer. , 2009, The New England journal of medicine.

[31]  E. Van Cutsem,et al.  Cetuximab and chemotherapy as initial treatment for metastatic colorectal cancer. , 2009, The New England journal of medicine.

[32]  C. Plass,et al.  Frequently methylated tumor suppressor genes in head and neck squamous cell carcinoma. , 2008, Cancer research.

[33]  M. Post,et al.  Iroquois genes influence proximo-distal morphogenesis during rat lung development. , 2006, American journal of physiology. Lung cellular and molecular physiology.

[34]  Z. Trajanoski,et al.  Effector memory T cells, early metastasis, and survival in colorectal cancer. , 2005, The New England journal of medicine.

[35]  M. Mareel,et al.  Commutators of PAR-1 signaling in cancer cell invasion reveal an essential role of the Rho–Rho kinase axis and tumor microenvironment , 2005, Oncogene.

[36]  L. Coussens,et al.  Cancer: An inflammatory link , 2004, Nature.

[37]  Anne J. Ridley,et al.  ROCKs: multifunctional kinases in cell behaviour , 2003, Nature Reviews Molecular Cell Biology.

[38]  D. Kass,et al.  Cardiomyopathy in Irx4-Deficient Mice Is Preceded by Abnormal Ventricular Gene Expression , 2001, Molecular and Cellular Biology.

[39]  R. Dildrop,et al.  Organization of mouse Iroquois homeobox genes in two clusters suggests a conserved regulation and function in vertebrate development. , 2000, Genome research.

[40]  B. Kaina,et al.  Rho GTPases are over‐expressed in human tumors , 1999, International journal of cancer.

[41]  P. Proost,et al.  Isolation of the CXC chemokines ENA‐78, GROα and GROγ from tumor cells and leukocytes reveals NH2‐terminal heterogeneity , 1999 .

[42]  A. Billiau,et al.  The neutrophil‐activating proteins interleukin 8 and β‐thromboglobulin: in vitro and in vivo comparison of NH2‐terminally processed forms , 1990, European journal of immunology.

[43]  Jun Liang,et al.  Expression of RhoA and RhoC in colorectal carcinoma and its relations with clinicopathological parameters , 2009, Clinical chemistry and laboratory medicine.