Genomes and Genes
RNA Binding Protein CUGBP2 in Intestinal Epithelium
Principal Investigator: Shrikant Anant
Abstract: DESCRIPTION (provided by applicant): The broad goal of this application is to understand the mechanisms by which RNA binding protein CUGBP2 regulates gene expression at the posttranscriptional level of mRNA stability and translation in intestinal epithelial cells. Overexpression of the protein in cancer cells results in cell death. We have determined that CUGBP2 interacts with AU-rich sequences in the 3'untranslated region of cyclooxygenase-2 and Mcl-1 mRNAs and upon binding downregulates the translation of both mRNAs. We have also determined that CUGBP2 levels are decreased in cancer cells but its expression is elevated in cells undergoing mitotic catastrophe. In addition, CUGBP2 is regulated at the levels of transcription by three different promoters. Activation from promoters located upstream from the commonly used proximal promoter results in the inclusion of additional amino acids in the N-terminus of the protein. Our studies suggest that the consequence of this addition is differences in cellular localization of the protein, but more importantly in the activity of the protein. The variants with the added amino acids do not affect cell viability. In addition, there are differential effects on target gene splicing with the three variants. Based on these observations, we have proposed to determine three aims. In Aim 1, we will determine the mechanism(s) by which the three CUGBP2 promoters are regulated. In addition, CUGBP2 is regulated at the posttranscriptional level of alternative splicing resulting in the novel inclusion of one intron in the 5'untranslated region. We will identify the cis-acting sequences and trans-acting factors regulating this process. In Aim 2, we will determine the cellular functions of CUGBP2. We have identified cellular factors that bind to CUGBP2. We will perform systematic deletion and fine mutagenesis to identify the domains in CUGBP2 that are involved in RNA:protein and protein:protein interactions. In addition, we will determine the CUGBP2 domains that regulate CUGBP2 localization under basal conditions and when the cells are exposed to 3-irradiation. We will also determine the effect of these interactions on CUGBP2 mediated RNA splicing, mRNA stability and translation regulation. In Aim 3, we will determine whether the CUGBP2 gene is both a novel tumor suppressor and a protooncogene. We will determine the expression levels of the three isoforms in a panel of human colon tumors. Furthermore, we will determine whether the different CUGBP2 isoforms affect tumor behavior in xenograft models. Completion of these experiments should give us a better understanding of how the RNA binding protein CUGBP2 functions in normal epithelial cells, and whether changes in the CUGBP2 expression that is observed in tumor cells is responsible for tumor behavior. PUBLIC HEALTH RELEVANCE: Colorectal cancer is the leading in cancer related deaths in the United States. Understanding how the normal cell progresses to a cancer will aid in our developing novel therapies for both diseases. We have identified a protein, CUGBP2 whose expression is lost in cancer cells. Restoring the protein into the cancer cell kills the cells. We are in the process of identifying how the gene expressing CUGBP2 is silenced in cancer cells so that we can determine ways to reverse the process. This might stop or slow down the tumorigenesis.
Funding Period: ----------------2009 - ---------------2011-
more information: NIH RePORT
- Reg IV activates the epidermal growth factor receptor/Akt/AP-1 signaling pathway in colon adenocarcinomasKumar S Bishnupuri
Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri 63110, USA
Gastroenterology 130:137-49. 2006..However, in vitro signal transduction pathway(s) utilized by Reg IV are not yet known...
- CDK-4 inhibitor P276 sensitizes pancreatic cancer cells to gemcitabine-induced apoptosisDharmalingam Subramaniam
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
Mol Cancer Ther 11:1598-608. 2012..Taken together, these data suggest that P276-Gem combination is a novel potent therapeutic agent that can target the Akt-mTOR signaling pathway to inhibit both tumor growth and angiogenesis...
- Honokiol in combination with radiation targets notch signaling to inhibit colon cancer stem cellsSivapriya Ponnurangam
Department of Molecular and Integrative Physiology, The University of Kansas Medical Center, Kansas City, Kansas 66160, USA
Mol Cancer Ther 11:963-72. 2012..These studies warrant further clinical evaluation for the combination of honokiol and IR for treating colon cancers...
- DCAMKL-1 regulates epithelial-mesenchymal transition in human pancreatic cells through a miR-200a-dependent mechanismSripathi M Sureban
Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
Cancer Res 71:2328-38. 2011..Moreover, they demonstrate a functional role for DCAMKL-1 in pancreatic cancer. Together, our results rationalize DCAMKL-1 as a therapeutic target for eradicating pancreatic cancers...
- Doublecortin and CaM kinase-like-1 and leucine-rich-repeat-containing G-protein-coupled receptor mark quiescent and cycling intestinal stem cells, respectivelyRandal May
Department of Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
Stem Cells 27:2571-9. 2009..Moreover, DCAMKL-1 can be used to isolate normal small intestinal stem cells and represents a novel research tool for regenerative medicine and cancer therapy...
- Translation regulatory factor RBM3 is a proto-oncogene that prevents mitotic catastropheS M Sureban
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126, USA
Oncogene 27:4544-56. 2008..These data demonstrate that the RNA stabilizing and translation regulatory protein RBM3 is a novel proto-oncogene that induces transformation when overexpressed and is essential for cells to progress through mitosis...
- Gastrin-mediated interleukin-8 and cyclooxygenase-2 gene expression: differential transcriptional and posttranscriptional mechanismsDharmalingam Subramaniam
Department of Internal Medicine, The University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
Gastroenterology 134:1070-82. 2008..Here, we have determined the intracellular mechanisms mediating gastrin-dependent gene expression...
- Diphenyl difluoroketone: a curcumin derivative with potent in vivo anticancer activityDharmalingam Subramaniam
Section of Digestive Diseases and Nutrition, Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73126, USA
Cancer Res 68:1962-9. 2008..Taken together, these data suggest that the novel curcumin-related compound EF24 is a potent antitumor agent that induces caspase-mediated apoptosis during mitosis and has significant therapeutic potential for gastrointestinal cancers...
- CUGBP2 downregulation by prostaglandin E2 protects colon cancer cells from radiation-induced mitotic catastropheGopalan Natarajan
Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
Am J Physiol Gastrointest Liver Physiol 294:G1235-44. 2008..Taken together, these data demonstrate that PGE(2) protects colon cancer cells from IR-induced mitotic catastrophe in part through suppression of CUGBP2 expression...
- Azoxymethane protects intestinal stem cells and reduces crypt epithelial mitosis through a COX-1-dependent mechanismTerrence E Riehl
Division of Gastroenterology, Department of Internal Medicine, Washington University School of Medicine, St Louis, Missouri, USA
Am J Physiol Gastrointest Liver Physiol 291:G1062-70. 2006..This suggests that COX-1-derived PGE(2) may play a key role in the early phase of intestinal tumorigenesis in response to DNA damage and suggests that COX-1 may be a potential therapeutic target in this model of colon cancer...
- Dysregulation of Reg gene expression occurs early in gastrointestinal tumorigenesis and regulates anti-apoptotic genesKumar S Bishnupuri
Division of Gastroenterology, Siteman Cancer Center, Washington University School of Medicine, St Louis, Missouri 63110, and Massachusetts General Hospital, Boston, USA
Cancer Biol Ther 5:1714-20. 2006..Furthermore, increased expression of Reg genes, specifically Reg IV contribute to adenoma formation and lead to increased resistance to apoptotic cell death in CRC...
- EP4 mediates PGE2 dependent cell survival through the PI3 kinase/AKT pathwayRobert J George
Washington University School of Medicine, Department of Internal Medicine, St Louis, Missouri 63110, USA
Prostaglandins Other Lipid Mediat 83:112-20. 2007..These findings have critical implications regarding the mechanism and potential application of PGE(2) receptor specific inhibition in cancer therapy...
- Functional antagonism between RNA binding proteins HuR and CUGBP2 determines the fate of COX-2 mRNA translationSripathi M Sureban
Department of Medicine, University of Oklahoma Health Science Center, Oklahoma City, Oklahoma 73104, USA
Gastroenterology 132:1055-65. 2007..This study aimed to determine the antagonism between these proteins on COX-2 expression...
- Translation inhibition during cell cycle arrest and apoptosis: Mcl-1 is a novel target for RNA binding protein CUGBP2Dharmalingam Subramaniam
Dept of Medicine, Univ of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, USA
Am J Physiol Gastrointest Liver Physiol 294:G1025-32. 2008..Taken together, these data demonstrate that CUGBP2 inhibits Mcl-1 expression by inhibiting Mcl-1 mRNA translation, resulting in driving the cells to apoptosis during the G(2) phase of the cell cycle...
- Novel intestinal splice variants of RNA-binding protein CUGBP2: isoform-specific effects on mitotic catastropheSatish Ramalingam
Dept of Medicine, Univ of Oklahoma Health Sciences Ctr, 920 Stanton L Young Blvd, WP1360, Oklahoma City, OK 73126, USA
Am J Physiol Gastrointest Liver Physiol 294:G971-81. 2008..Taken together, these data demonstrate that cells expressing CUGBP2 variant 1 undergo apoptosis during mitosis, suggesting mitotic catastrophe...
- Translational inhibition of colonic epithelial heat shock proteins by IFN-gamma and TNF-alpha in intestinal inflammationShien Hu
The Martin Boyer Laboratories, Department of Medicine, University of Chicago IBD Research Center, Chicago, Illinois, USA
Gastroenterology 133:1893-904. 2007..We examined the expression and regulation of iHsp in human and experimental inflammatory bowel diseases (IBD) and in vitro...
- Loss of p21Waf1/Cip1/Sdi1 enhances intestinal stem cell survival following radiation injuryRobert J George
Department of Internal Medicine, Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri, USA
Am J Physiol Gastrointest Liver Physiol 296:G245-54. 2009..Furthermore, the increase in crypt survival is associated with increased numbers of Msi-1- and survivin-expressing cells in regenerative crypts...
- 3,5-bis(2,4-difluorobenzylidene)-4-piperidone, a novel compound that affects pancreatic cancer growth and angiogenesisDharmalingam Subramaniam
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, KS 66160, USA
Mol Cancer Ther 10:2146-56. 2011..Taken together, these data suggest that DiFiD is a novel potent therapeutic agent that can target different aspects of the Notch signaling pathway to inhibit both tumor growth and angiogenesis...
- Honokiol radiosensitizes colorectal cancer cells: enhanced activity in cells with mismatch repair defectsZhiyun He
Department of Medicine, Lanzhou University Second Hospital, Gansu Province, China
Am J Physiol Gastrointest Liver Physiol 301:G929-37. 2011..These data demonstrate that honokiol is highly effective in radiosensitizing colorectal cancer cells, especially those with a mismatch repair defect...
- Crocetin: an agent derived from saffron for prevention and therapy for cancerWilliam G Gutheil
Pharmaceutical Sciences, School of Pharmacy, University of Missouri Kansas City, MO, USA
Curr Pharm Biotechnol 13:173-9. 2012..This review discusses the studies on cancer preventive potential of crocetin and its future use as an anticancer agent...
- RNA binding protein CUGBP2/CELF2 mediates curcumin-induced mitotic catastrophe of pancreatic cancer cellsDharmalingam Subramaniam
Department of Molecular and Integrative Physiology, University of Kansas Medical Center, Kansas City, Kansas, United States of America
PLoS ONE 6:e16958. 2011..Here, we have determined that curcumin modulates the expression of RNA binding protein CUGBP2 to inhibit pancreatic cancer growth...
- The curcuminoid CLEFMA selectively induces cell death in H441 lung adenocarcinoma cells via oxidative stressKaustuv Sahoo
Department of Pharmaceutical Sciences, University of Oklahoma Health Science Center, 1110 North Stonewall Avenue, Oklahoma, OK 73117, USA
Invest New Drugs 30:558-67. 2012..Based on these results, we conclude that induction of ROS is critical for the antiproliferative activity of CLEFMA and the Nrf2-mediated oxidative stress response fails to salvage H441 cells...
- Cancer stem cells: a novel paradigm for cancer prevention and treatmentDharmalingam Subramaniam
Medicine and Cell Biology, University of Oklahoma Health Sciences Center, 920 Stanton L Young Boulevard, WP1345, Oklahoma City, OK 73104, USA
Mini Rev Med Chem 10:359-71. 2010..Dietary phytochemicals possess anti-cancer properties and represent a promising approach for the prevention and treatment of many cancers...
- Reg IV regulates normal intestinal and colorectal cancer cell susceptibility to radiation-induced apoptosisKumar S Bishnupuri
Division of Gastroenterology, Washington University School of Medicine, St Louis, Missouri 63110, USA
Gastroenterology 138:616-26, 626.e1-2. 2010..Human CRC cells expressing higher levels of Reg IV gene and its protein product (Reg IV) are resistant to conventional therapies, including irradiation (IR). However, the underlying mechanism is not well defined...