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Stuckel AJ, Zeng S, Lyu Z, Zhang W, Zhang X, Dougherty U, Mustafi R, Khare T, Zhang Q, Joshi T, Bissonnette M, Khare S. Sprouty4 is epigenetically upregulated in human colorectal cancer. Epigenetics 2023; 18:2145068. [PMID: 36384366 PMCID: PMC9980603 DOI: 10.1080/15592294.2022.2145068] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Sprouty4 (SPRY4) has been frequently reported as a tumor suppressor and is therefore downregulated in various cancers. For the first time, we report that SPRY4 is epigenetically upregulated in colorectal cancer (CRC). In this study, we explored DNA methylation and hydroxymethylation levels of SPRY4 in CRC cells and patient samples and correlated these findings with mRNA and protein expression levels. Three loci within the promoter region of SPRY4 were evaluated for 5mC levels in CRC using the combined bisulfite restriction analysis. In addition, hydroxymethylation levels within SPRY4 were measured in CRC patients. Lastly, DNA methylation and mRNA expression data were extracted from CRC patients in multiple high-throughput data repositories like Gene Expression Omnibus and The Cancer Genome Atlas. Combined in vitro and in silico analysis of promoter methylation levels of SPRY4 clearly demonstrates that the distal promoter region undergoes hypomethylation in CRC patients and is associated with increased expression. Moreover, a decrease in gene body hydroxymethylation and an increase in gene body methylation within the coding region of SPRY4 were found in CRC patients and correlated with increased expression. SPRY4 is epigenetically upregulated in CRC by promoter hypomethylation and hypermethylation within the gene body that warrants future investigation of atypical roles of this established tumor suppressor.
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Affiliation(s)
- Alexei J. Stuckel
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, 65212, USA
| | - Shuai Zeng
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, 65201, USA,Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri, 65201, USA
| | - Zhen Lyu
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, 65201, USA,Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri, 65201, USA
| | - Wei Zhang
- Department of Preventive Medicine and the Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois, 60611, USA
| | - Xu Zhang
- Department of Medicine, University of Illinois, Chicago, Illinois, 60607, USA
| | - Urszula Dougherty
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition; the University of Chicago, Chicago, Illinois, 60637, USA
| | - Reba Mustafi
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition; the University of Chicago, Chicago, Illinois, 60637, USA
| | - Tripti Khare
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, 65212, USA
| | - Qiong Zhang
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, 65212, USA
| | - Trupti Joshi
- Bond Life Sciences Center, University of Missouri, Columbia, Missouri, 65201, USA,Institute for Data Science and Informatics, University of Missouri, Columbia, Missouri, 65211, USA,Department of Health Management and Informatics; School of Medicine, University of Missouri, Columbia, Missouri, 65212, USA
| | - Marc Bissonnette
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition; the University of Chicago, Chicago, Illinois, 60637, USA
| | - Sharad Khare
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, 65212, USA,Harry S. Truman Memorial Veterans’ Hospital, Columbia, Missouri, 65201, USA,CONTACT Sharad Khare Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, Missouri, 65212, USA
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Dougherty U, Mustafi R, Zhu H, Zhu X, Deb D, Meredith SC, Ayaloglu-Butun F, Fletcher M, Sanchez A, Pekow J, Deng Z, Amini N, Konda VJ, Rao VL, Sakuraba A, Kwesi A, Kupfer SS, Fichera A, Joseph L, Hart J, He F, He TC, West-Szymanski D, Li YC, Bissonnette M. Upregulation of polycistronic microRNA-143 and microRNA-145 in colonocytes suppresses colitis and inflammation-associated colon cancer. Epigenetics 2021; 16:1317-1334. [PMID: 33356812 PMCID: PMC8813074 DOI: 10.1080/15592294.2020.1863117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 11/08/2020] [Accepted: 12/07/2020] [Indexed: 12/25/2022] Open
Abstract
Because ADAM17 promotes colonic tumorigenesis, we investigated potential miRNAs regulating ADAM17; and examined effects of diet and tumorigenesis on these miRNAs. We also examined pre-miRNA processing and tumour suppressor roles of several of these miRNAs in experimental colon cancer. Using TargetScan, miR-145, miR-148a, and miR-152 were predicted to regulate ADAM17. miR-143 was also investigated as miR-143 and miR-145 are co-transcribed and associated with decreased tumour growth. HCT116 colon cancer cells (CCC) were co-transfected with predicted ADAM17-regulating miRNAs and luciferase reporters controlled by ADAM17-3'UTR. Separately, pre-miR-143 processing by colonic cells was measured. miRNAs were quantified by RT-PCR. Tumours were induced with AOM/DSS in WT and transgenic mice (Tg) expressing pre-miR-143/miR-145 under villin promoter. HCT116 transfection with miR-145, -148a or -152, but not scrambled miRNA inhibited ADAM17 expression and luciferase activity. The latter was suppressed by mutations in ADAM17-3'UTR. Lysates from colonocytes, but not CCC, processed pre-miR-143 and mixing experiments suggested CCC lacked a competency factor. Colonic miR-143, miR-145, miR-148a, and miR-152 were downregulated in tumours and more moderately by feeding mice a Western diet. Tg mice were resistant to DSS colitis and had significantly lower cancer incidence and tumour multiplicity. Tg expression blocked up-regulation of putative targets of miR-143 and miR-145, including ADAM17, K-Ras, XPO5, and SET. miR-145, miR-148a, and miR-152 directly suppress colonocyte ADAM17 and are down-regulated in colon cancer. This is the first direct demonstration of tumour suppressor roles for miR-143 and miR-145 in an in vivo model of colonic tumorigenesis.
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Affiliation(s)
| | - Reba Mustafi
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Hongyan Zhu
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Xiaorong Zhu
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Dilip Deb
- Department of Medicine, University of Chicago, Chicago IL, USA
| | | | | | | | - Arantxa Sanchez
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Joel Pekow
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Zifeng Deng
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Nader Amini
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Vani J Konda
- Department of Medicine, Baylor University, Dallas, TX, USA
| | - Vijaya L. Rao
- Department of Medicine, University of Chicago, Chicago IL, USA
| | | | - Akushika Kwesi
- Department of Medicine, University of Chicago, Chicago IL, USA
| | - Sonia S Kupfer
- Department of Medicine, University of Chicago, Chicago IL, USA
| | | | - Loren Joseph
- Departments of Pathology, Beth Israel, Harvard Medical School, Boston, MA, USA
| | - John Hart
- Departments of Pathology, University of Chicago, Chicago IL, USA
| | - Fang He
- Departments of Orthopedics, The University of Chicago, Chicago, IL, USA
| | - Tong-Chuan He
- Departments of Orthopedics, The University of Chicago, Chicago, IL, USA
| | | | - Yan Chun Li
- Department of Medicine, University of Chicago, Chicago IL, USA
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Stuckel AJ, Zhang W, Zhang X, Zeng S, Dougherty U, Mustafi R, Zhang Q, Perreand E, Khare T, Joshi T, West-Szymanski DC, Bissonnette M, Khare S. Correction: Stuckel, et al.; Enhanced CXCR4 Expression Associates with Increased Gene Body 5-Hydroxymethylcytosine Modification but Not Decreased Promoter Methylation in Colorectal Cancer. Cancers 2020, 12, 539. Cancers (Basel) 2020; 12:cancers12113104. [PMID: 33114273 PMCID: PMC7690871 DOI: 10.3390/cancers12113104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 10/15/2020] [Indexed: 11/21/2022] Open
Affiliation(s)
- Alexei J. Stuckel
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO 65212, USA; (A.J.S.); (Q.Z.); (E.P.); (T.K.)
| | - Wei Zhang
- Department of Preventive Medicine and The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
| | - Xu Zhang
- Department of Medicine, University of Illinois, Chicago, IL 60607, USA;
| | - Shuai Zeng
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65201, USA; (S.Z.); (T.J.)
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65201, USA
| | - Urszula Dougherty
- Section of Gastroenterology, Hepatology and Nutrition, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Reba Mustafi
- Section of Gastroenterology, Hepatology and Nutrition, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Qiong Zhang
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO 65212, USA; (A.J.S.); (Q.Z.); (E.P.); (T.K.)
| | - Elsa Perreand
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO 65212, USA; (A.J.S.); (Q.Z.); (E.P.); (T.K.)
| | - Tripti Khare
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO 65212, USA; (A.J.S.); (Q.Z.); (E.P.); (T.K.)
| | - Trupti Joshi
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65201, USA; (S.Z.); (T.J.)
- Institute for Data Science and Informatics, University of Missouri, Columbia, MO 65211, USA
- Department of Health Management and Informatics, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Diana C. West-Szymanski
- Section of Gastroenterology, Hepatology and Nutrition, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Marc Bissonnette
- Section of Gastroenterology, Hepatology and Nutrition, Department of Medicine, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Sharad Khare
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Missouri, Columbia, MO 65212, USA; (A.J.S.); (Q.Z.); (E.P.); (T.K.)
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65201, USA
- Correspondence: or
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Stuckel AJ, Zhang W, Zhang X, Zeng S, Dougherty U, Mustafi R, Zhang Q, Perreand E, Khare T, Joshi T, West-Szymanski DC, Bissonnette M, Khare S. Enhanced CXCR4 Expression Associates with Increased Gene Body 5-Hydroxymethylcytosine Modification but not Decreased Promoter Methylation in Colorectal Cancer. Cancers (Basel) 2020; 12:cancers12030539. [PMID: 32110952 PMCID: PMC7139960 DOI: 10.3390/cancers12030539] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/19/2020] [Accepted: 02/24/2020] [Indexed: 12/19/2022] Open
Abstract
In colorectal cancer (CRC), upregulation of the C-X-C motif chemokine receptor 4 (CXCR4) is correlated with metastasis and poor prognosis, highlighting the need to further elucidate CXCR4’s regulation in CRC. For the first time, DNA methylation and 5-hydroxymethylcytosine aberrations were investigated to better understand the epigenetic regulation of CXCR4 in CRC. CXCR4 expression levels were measured using qPCR and immunoblotting in normal colon tissues, primary colon cancer tissues and CRC cell lines. Publicly available RNA-seq and methylation data from The Cancer Genome Atlas (TCGA) were extracted from tumors from CRC patients. The DNA methylation status spanning CXCR4 gene was evaluated using combined bisulfite restriction analysis (COBRA). The methylation status in the CXCR4 gene body was analyzed using previously performed nano-hmC-seal data from colon cancers and adjacent normal colonic mucosa. CXCR4 expression levels were significantly increased in tumor stromal cells and in tumor colonocytes, compared to matched cell types from adjacent normal-appearing mucosa. CXCR4 promoter methylation was detected in a minority of colorectal tumors in the TCGA. The CpG island of the CXCR4 promoter showed increased methylation in three of four CRC cell lines. CXCR4 protein expression differences were also notable between microsatellite stable (MSS) and microsatellite instable (MSI) tumor cell lines. While differential methylation was not detected in CXCR4, enrichment of 5-hydroxymethylcytosine (5hmC) in CXCR4 gene bodies in CRC was observed compared to adjacent mucosa.
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Affiliation(s)
- Alexei J. Stuckel
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA (Q.Z.); (E.P.); (T.K.)
| | - Wei Zhang
- Department of Preventive Medicine and The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA;
| | - Xu Zhang
- Department of Medicine, University of Illinois, Chicago, IL 60607, USA;
| | - Shuai Zeng
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65201, USA; (S.Z.); (T.J.)
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, MO 65201, USA
| | - Urszula Dougherty
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Reba Mustafi
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Qiong Zhang
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA (Q.Z.); (E.P.); (T.K.)
| | - Elsa Perreand
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA (Q.Z.); (E.P.); (T.K.)
| | - Tripti Khare
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA (Q.Z.); (E.P.); (T.K.)
| | - Trupti Joshi
- Bond Life Sciences Center, University of Missouri, Columbia, MO 65201, USA; (S.Z.); (T.J.)
- Institute for Data Science and Informatics, University of Missouri, Columbia, MO 65211, USA
- Department of Health Management and Informatics, School of Medicine, University of Missouri, Columbia, MO 65212, USA
| | - Diana C. West-Szymanski
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Marc Bissonnette
- Department of Medicine, Section of Gastroenterology, Hepatology and Nutrition, The University of Chicago, Chicago, IL 60637, USA; (U.D.); (R.M.); (D.C.W.-S.); (M.B.)
| | - Sharad Khare
- Department of Medicine, Division of Gastroenterology and Hepatology, University of Missouri, Columbia, MO 65212, USA (Q.Z.); (E.P.); (T.K.)
- Harry S. Truman Memorial Veterans’ Hospital, Columbia, MO 65201, USA
- Correspondence:
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Dougherty U, Mustafi R, Haider HI, Khalil A, Souris JS, Joseph L, Hart J, Konda VJ, Zhang W, Pekow J, Li YC, Bissonnette M. Losartan and Vitamin D Inhibit Colonic Tumor Development in a Conditional Apc-Deleted Mouse Model of Sporadic Colon Cancer. Cancer Prev Res (Phila) 2019; 12:433-448. [PMID: 31088824 DOI: 10.1158/1940-6207.capr-18-0380] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Revised: 04/02/2019] [Accepted: 05/06/2019] [Indexed: 12/20/2022]
Abstract
Colorectal cancer is a leading cause of cancer deaths. The renin-angiotensin system (RAS) is upregulated in colorectal cancer, and epidemiologic studies suggest RAS inhibitors reduce cancer risk. Because vitamin D (VD) receptor negatively regulates renin, we examined anticancer efficacy of VD and losartan (L), an angiotensin receptor blocker. Control Apc+/LoxP mice and tumor-forming Apc+/LoxP Cdx2P-Cre mice were randomized to unsupplemented Western diet (UN), or diets supplemented with VD, L, or VD+L, the latter to assess additive or synergistic effects. At 6 months, mice were killed. Plasma Ca2+, 25(OH)D3, 1α, 25(OH)2D3, renin, and angiotensin II (Ang II) were quantified. Colonic transcripts were assessed by qPCR and proteins by immunostaining and blotting. Cancer incidence and tumor burden were significantly lower in Cre+ VD and Cre+ L, but not in the Cre+ VD+L group. In Apc+/LoxP mice, VD increased plasma 1,25(OH)2D3 and colonic VDR. In Apc+/LoxP-Cdx2P-Cre mice, plasma renin and Ang II, and colonic tumor AT1, AT2, and Cyp27B1 were increased and VDR downregulated. L increased, whereas VD decreased plasma renin and Ang II in Cre+ mice. VD or L inhibited tumor development, while exerting differential effects on plasma VD metabolites and RAS components. We speculate that AT1 is critical for tumor development, whereas RAS suppression plays a key role in VD chemoprevention. When combined with L, VD no longer increases active VD and colonic VDR in Cre- mice nor suppresses renin and Ang II in Cre+ mice, likely contributing to lack of chemopreventive efficacy of the combination.
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Affiliation(s)
| | - Reba Mustafi
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Haider I Haider
- Department of Medicine, University of Chicago, Chicago, Illinois
| | | | - Jeffrey S Souris
- Department of Radiology, University of Chicago, Chicago, Illinois
| | - Loren Joseph
- Department of Pathology, Beth Israel, Harvard Medical School, Boston, Massachusetts
| | - John Hart
- Department of Pathology, University of Chicago, Chicago, Illinois
| | - Vani J Konda
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Wei Zhang
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | - Joel Pekow
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Yan Chun Li
- Department of Medicine, University of Chicago, Chicago, Illinois
| | - Marc Bissonnette
- Department of Medicine, University of Chicago, Chicago, Illinois.
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Bissonnette BM, Dougherty U, Mustafi R, Haider HI, Joseph L, Souris J, Hart JA, Pewkow JR, LI YC. CXCR4 inhibitor, MSX‐122 suppresses AOM‐induced colon cancer in Apc+/Min mouse. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.677.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Pekow J, Meckel K, Dougherty U, Huang Y, Chen X, Almoghrabi A, Mustafi R, Ayaloglu-Butun F, Deng Z, Haider HI, Hart J, Rubin DT, Kwon JH, Bissonnette M. miR-193a-3p is a Key Tumor Suppressor in Ulcerative Colitis-Associated Colon Cancer and Promotes Carcinogenesis through Upregulation of IL17RD. Clin Cancer Res 2017; 23:5281-5291. [PMID: 28600480 DOI: 10.1158/1078-0432.ccr-17-0171] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 05/02/2017] [Accepted: 06/05/2017] [Indexed: 12/30/2022]
Abstract
Purpose: Patients with ulcerative colitis are at increased risk for colorectal cancer, although mechanisms underlying neoplastic transformation are poorly understood. We sought to evaluate the role of microRNAs in neoplasia development in this high-risk population.Experimental Design: Tissue from 12 controls, 9 ulcerative colitis patients without neoplasia, and 11 ulcerative colitis patients with neoplasia was analyzed. miRNA array analysis was performed and select miRNAs assayed by real-time PCR on the discovery cohort and a validation cohort. DNA methylation of miR-193a was assessed. Following transfection of miR-193a-3p, proliferation, IL17RD expression, and luciferase activity of the 3'UTR of IL17RD were measured. Tumor growth in xenografts as well as EGFR signaling were assessed in HCT116 cells expressing IL17RD with either a mutant 3' untranslated region (UTR) or wild-type (WT) 3'UTR.Results: miR-31, miR-34a, miR-106b, and miR-193a-3p were significantly dysregulated in ulcerative colitis-neoplasia and adjacent tissue. Significant down-regulation of miR-193a-3p was also seen in an independent cohort of ulcerative colitis cancers. Changes in methylation of miR-193a or expression of pri-miR-193a were not observed in ulcerative colitis cancer. Transfection of miR-193a-3p resulted in decreased proliferation, and identified IL17RD as a direct target of miR-193a-3p. IL17RD expression was increased in ulcerative colitis cancers, and miR-193a-3p treatment decreased growth and EGFR signaling of HCT116 cells in xenografts expressing both IL17RD with WT 3'UTR compared with cells expressing IL17RD with mutant 3'UTR.Conclusions: miR-193a-3p is downregulated in ulcerative colitis neoplasia, and its loss promotes carcinogenesis through upregulation of IL17RD. These findings provide novel insight into inflammation-driven colorectal cancer and could suggest new therapeutic targets in this high-risk population. Clin Cancer Res; 23(17); 5281-91. ©2017 AACR.
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Affiliation(s)
- Joel Pekow
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois.
| | - Katherine Meckel
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Urszula Dougherty
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Yong Huang
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Xindi Chen
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Anas Almoghrabi
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Reba Mustafi
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Fatma Ayaloglu-Butun
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Zifeng Deng
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - Haider I Haider
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - John Hart
- University of Chicago, Department of Pathology, Chicago, Illinois
| | - David T Rubin
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
| | - John H Kwon
- University of Texas Southwestern, Digestive and Liver Disease Division, Dallas, Texas
| | - Marc Bissonnette
- University of Chicago, Section of Gastroenterology, Hepatology, and Nutrition, Chicago, Illinois
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Mustafi R, Dougherty U, Mustafi D, Ayaloglu-Butun F, Fletcher M, Adhikari S, Sadiq F, Meckel K, Haider HI, Khalil A, Pekow J, Konda V, Joseph L, Hart J, Fichera A, Li YC, Bissonnette M. ADAM17 is a Tumor Promoter and Therapeutic Target in Western Diet-associated Colon Cancer. Clin Cancer Res 2016; 23:549-561. [PMID: 27489286 DOI: 10.1158/1078-0432.ccr-15-3140] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 07/18/2016] [Accepted: 07/25/2016] [Indexed: 12/30/2022]
Abstract
PURPOSE Epidermal growth factor receptors (EGFR) are required for tumor promotion by Western diet. The metalloprotease, ADAM17 activates EGFR by releasing pro-EGFR ligands. ADAM17 is regulated by G-protein-coupled receptors, including CXCR4. Here we investigated CXCR4-ADAM17 crosstalk and examined the role of ADAM17 in tumorigenesis. EXPERIMENTAL DESIGN We used CXCR4 inhibitor, AMD3100 and ADAM17 inhibitor, BMS566394 to assess CXCR4-ADAM17 crosstalk in colon cancer cells. We compared the expression of CXCR4 ligand, CXCL2, and ADAM17 in mice fed Western diet versus standard diet. Separately, mice were treated with marimastat, a broad-spectrum ADAM17 inhibitor, or AMD3100 to assess EGFR activation by ADAM17 and CXCR4. Using Apc-mutant Min mice, we investigated the effects of ADAM17/10 inhibitor INCB3619 on tumorigenesis. To assess the effects of colonocyte ADAM17, mice with ADAM17 conditional deletion were treated with azoxymethane (AOM). ADAM17 expression was also compared in colonocytes from primary human colon cancers and adjacent mucosa. RESULTS CXCL12 treatment activated colon cancer cell EGFR signals, and CXCR4 or ADAM17 blockade reduced this activation. In vivo, Western diet increased CXCL12 in stromal cells and TGFα in colonocytes. Marimastat or AMD3100 caused >50% reduction in EGFR signals (P < 0.05). In Min mice, INCB3619 reduced EGFR signals in adenomas and inhibited intestinal tumor multiplicity (P < 0.05). In the AOM model, colonocyte ADAM17 deletion reduced EGFR signals and colonic tumor development (P < 0.05). Finally, ADAM17 was upregulated >2.5-fold in human malignant colonocytes. CONCLUSIONS ADAM17 is a Western diet-inducible enzyme activated by CXCL12-CXCR4 signaling, suggesting the pathway: Western diet→CXCL12→CXCR4→ADAM17→TGFα→EGFR. ADAM17 might serve as a druggable target in chemoprevention strategies. Clin Cancer Res; 23(2); 549-61. ©2016 AACR.
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Affiliation(s)
- Reba Mustafi
- Department of Medicine, University of Chicago, Chicago IL 60637
| | | | - Devkumar Mustafi
- Department of Radiology, University of Chicago, Chicago IL 60637
| | | | | | | | - Farhana Sadiq
- Department of Medicine, University of Chicago, Chicago IL 60637
| | | | - Haider I Haider
- Department of Medicine, University of Chicago, Chicago IL 60637
| | | | - Joel Pekow
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Vani Konda
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Loren Joseph
- Department of Pathology, University of Chicago, Chicago IL 60637
| | - John Hart
- Department of Pathology, University of Chicago, Chicago IL 60637
| | | | - Yan Chun Li
- Department of Medicine, University of Chicago, Chicago IL 60637
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Pekow J, Meckel K, Dougherty U, Butun F, Mustafi R, Lim J, Crofton C, Chen X, Joseph L, Bissonnette M. Tumor suppressors miR-143 and miR-145 and predicted target proteins API5, ERK5, K-RAS, and IRS-1 are differentially expressed in proximal and distal colon. Am J Physiol Gastrointest Liver Physiol 2015; 308:G179-87. [PMID: 25477374 PMCID: PMC4312953 DOI: 10.1152/ajpgi.00208.2014] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The colon differs regionally in local luminal environment, excretory function, and gene expression. Polycistronic microRNA (miR)-143 and miR-145 are downregulated early in colon cancer. We asked if these microRNAs (miRNAs) might be differentially expressed in the proximal vs. the distal colon, contributing to regional differences in protein expression. Primary transcripts and mature miR-143 and miR-145 were quantified by real-time PCR, putative targets were measured by Western blotting, and DNA methylation was assessed by sequencing bisulfite-treated DNA in proximal and distal normal colonic mucosa as well as colon cancers. Putative targets of these miRNAs were assessed following transfection with miR-143 or miR-145. Mean expression of mature miR-143 and miR-145 was 2.0-fold (P < 0.001) and 1.8-fold (P = 0.03) higher, respectively, in proximal than distal colon. DNA methylation or primary transcript expression of these miRNAs did not differ by location. In agreement with increased expression of miR-143 and miR-145 in proximal colon, predicted targets of these miRNAs, apoptosis inhibitor 5 (API5), ERK5, K-RAS, and insulin receptor substrate 1 (IRS-1), which are cell cycle and survival regulators, were expressed at a lower level in proximal than distal colon. Transfection of HCA-7 colon cancer cells with miR-145 downregulated IRS-1, and transfection of HT-29 colon cancer cells with miR-143 decreased K-RAS and ERK5 expression. In conclusion, miR-143 and miR-145 and the predicted target proteins API5, ERK5, K-RAS, and IRS-1 display regional differences in expression in the colon. We speculate that differences in these tumor suppressors might contribute to regional differences in normal colonic gene expression and modulate site-specific differences in malignant predisposition.
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Affiliation(s)
- Joel Pekow
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Katherine Meckel
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Urszula Dougherty
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Fatma Butun
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Reba Mustafi
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - John Lim
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Charis Crofton
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Xindi Chen
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
| | - Loren Joseph
- 2Department of Pathology, University of Chicago, Chicago, Illinois
| | - Marc Bissonnette
- 1Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago, Chicago, Illinois; and
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10
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Dougherty U, Mustafi R, Sadiq F, Almoghrabi A, Mustafi D, Kreisheh M, Sundaramurthy S, Liu W, Konda VJ, Pekow J, Khare S, Hart J, Joseph L, Wyrwicz A, Karczmar GS, Li YC, Bissonnette M. The renin-angiotensin system mediates EGF receptor-vitamin d receptor cross-talk in colitis-associated colon cancer. Clin Cancer Res 2014; 20:5848-5859. [PMID: 25212605 DOI: 10.1158/1078-0432.ccr-14-0209] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
PURPOSE We previously showed that EGF receptor (EGFR) promotes tumorigenesis in the azoxymethane/dextran sulfate sodium (AOM/DSS) model, whereas vitamin D suppresses tumorigenesis. EGFR-vitamin D receptor (VDR) interactions, however, are incompletely understood. Vitamin D inhibits the renin-angiotensin system (RAS), whereas RAS can activate EGFR. We aimed to elucidate EGFR-VDR cross-talk in colorectal carcinogenesis. EXPERIMENTAL DESIGN To examine VDR-RAS interactions, we treated Vdr(+/+) and Vdr(-/-) mice with AOM/DSS. Effects of VDR on RAS and EGFR were examined by Western blotting, immunostaining, and real-time PCR. We also examined the effect of vitamin D3 on colonic RAS in Vdr(+/+) mice. EGFR regulation of VDR was examined in hypomorphic Egfr(Waved2) (Wa2) and Egfr(wild-type) mice. Angiotensin II (Ang II)-induced EGFR activation was studied in cell culture. RESULTS Vdr deletion significantly increased tumorigenesis, activated EGFR and β-catenin signaling, and increased colonic RAS components, including renin and angiotensin II. Dietary VD3 supplementation suppressed colonic renin. Renin was increased in human colon cancers. In studies in vitro, Ang II activated EGFR and stimulated colon cancer cell proliferation by an EGFR-mediated mechanism. Ang II also activated macrophages and colonic fibroblasts. Compared with tumors from Egfr(Waved2) mice, tumors from Egfr(wild-type) mice showed upregulated Snail1, a suppressor of VDR, and downregulated VDR. CONCLUSIONS VDR suppresses the colonic RAS cascade, limits EGFR signals, and inhibits colitis-associated tumorigenesis, whereas EGFR increases Snail1 and downregulates VDR in colonic tumors. Taken together, these results uncover a RAS-dependent mechanism mediating EGFR and VDR cross-talk in colon cancer.
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Affiliation(s)
| | - Reba Mustafi
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Farhana Sadiq
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Anas Almoghrabi
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Devkumar Mustafi
- Department of Radiology, University of Chicago, Chicago IL 60637
| | - Maggi Kreisheh
- Department of Medicine, University of Chicago, Chicago IL 60637
| | | | - Weicheng Liu
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Vani J Konda
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Joel Pekow
- Department of Medicine, University of Chicago, Chicago IL 60637
| | - Sharad Khare
- Department of Medicine, University of Missouri, Harry S. Truman Memorial Veterans' Hospital, Columbia, MO 65201
| | - John Hart
- Department of Pathology, University of Chicago, Chicago IL 60637
| | - Loren Joseph
- Department of Pathology, University of Chicago, Chicago IL 60637
| | - Alice Wyrwicz
- Center for Basic MR Research, Department of Radiology, NorthShore University Health System, Evanston, IL 60201
| | | | - Yan Chun Li
- Department of Medicine, University of Chicago, Chicago IL 60637
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Mustafi R, Dougherty U, Shah H, Dehghan H, Gliksberg A, Wu J, Zhu H, Joseph L, Hart J, Dive C, Fichera A, Threadgill D, Bissonnette M. Both stromal cell and colonocyte epidermal growth factor receptors control HCT116 colon cancer cell growth in tumor xenografts. Carcinogenesis 2012; 33:1930-9. [PMID: 22791816 DOI: 10.1093/carcin/bgs231] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Colon cancer growth requires growth-promoting interactions between malignant colonocytes and stromal cells. Epidermal growth factor receptors (EGFR) are expressed on colonocytes and many stromal cells. Furthermore, EGFR is required for efficient tumorigenesis in experimental colon cancer models. To dissect the cell-specific role of EGFR, we manipulated receptor function on stromal cells and cancer cells. To assess the role of stromal EGFR, HCT116 human colon cancer cells were implanted into immunodeficient mice expressing dominant negative (DN) Egfr(Velvet/+) or Egfr(+/+). To assess the role of cancer cell EGFR, HCT116 transfectants expressing inducible DN-Egfr were implanted into immunodeficient mice. To dissect EGFR signals in vitro, we examined colon cancer cells in monoculture or in cocultures with fibroblasts for EGFR transactivation and prostaglandin synthase 2 (PTGS2) induction. EGFR signals were determined by blotting, immunostaining and real-time PCR. Tumor xenografts in Egfr(Velvet/+) mice were significantly smaller than tumors in Egfr(+/+) mice, with decreased proliferation (Ki67) and increased apoptosis (cleaved caspase-3) in cancer cells and decreased stromal blood vessels. Mouse stromal transforming growth factor alpha (TGFA), amphiregulin (AREG), PTGS2 and Il1b and interleukin-1 receptor 1 (Il1r1) transcripts and cancer cell beta catenin (CTNNB1) and cyclin D1 (CCND1) were significantly lower in tumors obtained from Egfr(Velvet/+) mice. DN-EGFR HCT116 transfectants also formed significantly smaller tumors with reduced mouse Areg, Ptgs2, Il1b and Il1r1 transcripts. Coculture increased Caco-2 phospho-active ERBB (pERBB2), whereas DN-EGFR in Caco-2 cells suppressed fibroblast PTGS2 and prostaglandin E2 (PGE2). In monoculture, interleukin 1 beta (IL1B) transactivated EGFR in HCT116 cells. Stromal cell and colonocyte EGFRs are required for robust EGFR signals and efficient tumor growth, which involve EGFR-interleukin-1 crosstalk.
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Affiliation(s)
- Reba Mustafi
- Department of Paterson Institute, Manchester, UK
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12
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Pekow JR, Dougherty U, Mustafi R, Zhu H, Kocherginsky M, Rubin DT, Hanauer SB, Hart J, Chang EB, Fichera A, Joseph LJ, Bissonnette M. miR-143 and miR-145 are downregulated in ulcerative colitis: putative regulators of inflammation and protooncogenes. Inflamm Bowel Dis 2012; 18:94-100. [PMID: 21557394 PMCID: PMC3931730 DOI: 10.1002/ibd.21742] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/15/2011] [Accepted: 03/24/2011] [Indexed: 12/11/2022]
Abstract
BACKGROUND miR-143 and miR-145 are believed to function as colon cancer tumor suppressors, as they inhibit colon cancer cell growth and are downregulated in sporadic colonic tumors. We speculated that miR-143 and miR-145 might also be downregulated and contribute to malignant transformation of colonic epithelium in longstanding ulcerative colitis (UC). METHODS Biopsies were obtained 20 cm proximal to the anus from individuals with quiescent UC and from normal controls. RNA and proteins were extracted and measured. miR-143 and miR-145 were quantified by real-time polymerase chain reaction (PCR) and miR-145 was also assessed by in situ hybridization. Putative targets of these miRNAs, K-RAS, API5, MEK-2 (miR-143), and IRS-1 (miR-145) were determined by western blotting. To assess the effects of miR-143 and miR-145 on these predicted targets, HCT116 and HCA-7 colorectal cancer cells were transfected with miR-143 and miR-145 and expression levels of these proteins were measured. RESULTS In UC, miR-143 and miR-145 were significantly downregulated 8.3-fold (3.4-20.1) (P < 0.0001) and 4.3-fold (2.3-7.8) (P < 0.0001), respectively, compared to normal colon. In contrast, IRS-1, K-RAS, API5, and MEK-2 were upregulated in UC, consistent with their assignments as targets of these miRNAs. Furthermore, transfected miR-143 and miR-145 significantly downregulated these proteins in HCT116 or HCA-7 cells. CONCLUSIONS Compared to normal colonic mucosa, in chronic UC miR-143 and miR-145 were significantly downregulated and their predicted targets, IRS-1, K-RAS, API5, and MEK-2 were upregulated. We postulate that loss of these tumor suppressor miRNAs predispose to chronic inflammation and neoplastic progression in IBD.
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Affiliation(s)
- Joel R. Pekow
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | - Urszula Dougherty
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | - Reba Mustafi
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | - Hongyan Zhu
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | | | - David T. Rubin
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | - Stephen B. Hanauer
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | - John Hart
- Department of Pathology, University of Chicago; Chicago, IL
| | - Eugene B. Chang
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
| | | | | | - Marc Bissonnette
- Section of Gastroenterology, Hepatology, and Nutrition, University of Chicago; Chicago, IL
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Dougherty U, Mustafi R, Wang Y, Musch MW, Wang CZ, Konda VJ, Kulkarni A, Hart J, Dawson G, Kim KE, Yuan CS, Chang EB, Bissonnette M. American ginseng suppresses Western diet-promoted tumorigenesis in model of inflammation-associated colon cancer: role of EGFR. Altern Ther Health Med 2011; 11:111. [PMID: 22070864 PMCID: PMC3227598 DOI: 10.1186/1472-6882-11-111] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2011] [Accepted: 11/09/2011] [Indexed: 02/06/2023]
Abstract
Background Western diets increase colon cancer risk. Epidemiological evidence and experimental studies suggest that ginseng can inhibit colon cancer development. In this study we asked if ginseng could inhibit Western diet (20% fat) promoted colonic tumorigenesis and if compound K, a microbial metabolite of ginseng could suppress colon cancer xenograft growth. Methods Mice were initiated with azoxymethane (AOM) and, two weeks later fed a Western diet (WD, 20% fat) alone, or WD supplemented with 250-ppm ginseng. After 1 wk, mice received 2.5% dextran sulfate sodium (DSS) for 5 days and were sacrificed 12 wks after AOM. Tumors were harvested and cell proliferation measured by Ki67 staining and apoptosis by TUNEL assay. Levels of EGF-related signaling molecules and apoptosis regulators were determined by Western blotting. Anti-tumor effects of intraperitoneal compound K were examined using a tumor xenograft model and compound K absorption measured following oral ginseng gavage by UPLC-mass spectrometry. Effects of dietary ginseng on microbial diversity were measured by analysis of bacterial 16S rRNA. Results Ginseng significantly inhibited colonic inflammation and tumorigenesis and concomitantly reduced proliferation and increased apoptosis. The EGFR cascade was up-regulated in colonic tumors and ginseng significantly reduced EGFR and ErbB2 activation and Cox-2 expression. Dietary ginseng altered colonic microbial diversity, and bacterial suppression with metronidazole reduced serum compound K following ginseng gavage. Furthermore, compound K significantly inhibited tumor xenograft growth. Conclusions Ginseng inhibited colonic inflammation and tumorigenesis promoted by Western diet. We speculate that the ginseng metabolite compound K contributes to the chemopreventive effects of this agent in colonic tumorigenesis.
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14
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Wang HL, Hart J, Fan L, Mustafi R, Bissonnette M. Upregulation of glycogen synthase kinase 3β in human colorectal adenocarcinomas correlates with accumulation of CTNNB1. Clin Colorectal Cancer 2011; 10:30-6. [PMID: 21609933 DOI: 10.3816/ccc.2011.n.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
INTRODUCTION Mutations of the adenomatous polyposis coli (APC) tumor suppressor gene or the CTNNB1 protooncogene have been implicated in the initiation of most human colorectal epithelial neoplasms. Glycogen synthase kinase 3β (GSK3B) serves a critical role in regulating their functions by phosphorylating both APC and CTNNB1 to facilitate CTNNB1 degradation. The current studies were performed to investigate whether GSK3B itself is regulated during the process of colorectal tumorigenesis. PATIENTS AND METHODS We examined the expression of GSK3B and CTNNB1 in tissue samples from 24 human colorectal adenocarcinomas by Western immunoblotting analysis, kinase activity assays and immunohistochemistry. Normal colonic mucosa from the same colectomy specimens were used as a reference for comparison. RESULTS We demonstrated that GSK3B expression levels and kinase activities were markedly and significantly increased in colorectal adenocarcinomas in all 24 cases compared with paired adjacent normal-appearing colonic mucosa. These increases correlated with significantly increased expression of CTNNB1 in the same tumors. Similar results were obtained in several cultured human colon cancer cell lines, demonstrating GSK3B levels correlated with CTNNB1 expression. CONCLUSION Though APC and CTNNB1 regulation by GSK3B are frequently disrupted by mutations in colon cancers, our observations suggest that increased functional GSK3B might drive other growth-promoting signals in colorectal tumorigenesis.
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Affiliation(s)
- Hanlin L Wang
- Department of Pathology and Laboratory Medicine, Cedars-Sinai Medical Center, Los Angeles, CA, USA
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15
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Zhu H, Dougherty U, Robinson V, Mustafi R, Pekow J, Kupfer S, Li YC, Hart J, Goss K, Fichera A, Joseph L, Bissonnette M. EGFR signals downregulate tumor suppressors miR-143 and miR-145 in Western diet-promoted murine colon cancer: role of G1 regulators. Mol Cancer Res 2011; 9:960-75. [PMID: 21653642 PMCID: PMC3819602 DOI: 10.1158/1541-7786.mcr-10-0531] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Epidermal growth factor receptors (EGFR) contribute to colonic tumorigenesis in experimental models of colon cancer. We previously showed that EGFR was also required for colonic tumor promotion by Western diet. The goal of this study was to identify EGFR-regulated microRNAs that contribute to diet-promoted colonic tumorigenesis. Murine colonic tumors from Egfr(wt) and hypomorphic Egfr(wa2) mice were screened using micro RNA (miRNA) arrays and miR-143 and miR-145 changes confirmed by Northern, real-time PCR, and in situ analysis. Rodent and human sporadic and ulcerative colitis (UC)-associated colon cancers were examined for miR-143 and miR-145. Effects of EGFR on miR-143 and miR-145 expression were assessed in murine and human colonic cells and their putative targets examined in vitro and in vivo. miR-143 and miR-145 were readily detected in normal colonocytes and comparable in Egfr(wt) and Egfr(wa2) mice. These miRNAs were downregulated in azoxymethane and inflammation-associated colonic tumors from Egfr(wt) mice but upregulated in Egfr(wa2) tumors. They were also reduced in human sporadic and UC colon cancers. EGFR signals suppressed miR-143 and miR-145 in human and murine colonic cells. Transfected miR-143 and miR-145 inhibited HCT116 cell growth in vitro and in vivo and downregulated G(1) regulators, K-Ras, MYC, CCND2, cdk6, and E2F3, putative or established targets of these miRNAs. miRNA targets Ras and MYC were increased in colonic tumors from Egfr(wt) but not Egfr(wa2) mice fed a Western diet. EGFR suppresses miR-143 and miR-145 in murine models of colon cancer. Furthermore, Western diet unmasks the tumor suppressor roles of these EGFR-regulated miRNAs.
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MESH Headings
- Animals
- Antibodies, Monoclonal/pharmacology
- Antibodies, Monoclonal, Humanized
- Azoxymethane/pharmacology
- Cetuximab
- Colitis, Ulcerative/complications
- Colitis, Ulcerative/metabolism
- Colonic Neoplasms/etiology
- Colonic Neoplasms/genetics
- Colonic Neoplasms/metabolism
- Dextran Sulfate/pharmacology
- Diet/adverse effects
- Down-Regulation
- ErbB Receptors/antagonists & inhibitors
- ErbB Receptors/genetics
- ErbB Receptors/metabolism
- G1 Phase/genetics
- Gene Expression Regulation, Neoplastic
- Genes, Tumor Suppressor
- HCT116 Cells
- Humans
- Mice
- MicroRNAs/genetics
- Neoplasms, Experimental/etiology
- Neoplasms, Experimental/genetics
- Neoplasms, Experimental/metabolism
- Rats
- Signal Transduction
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | - Marc Bissonnette
- To Whom Correspondence Should be Addressed: Marc Bissonnette, M.D, Department of Medicine, University of Chicago Hospitals and Clinics, 900 East 57 Street, Chicago, IL 60637; Telephone: (773) 702-8597 FAX: (773) 702-2281
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16
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Zheng W, Wong KE, Zhang Z, Dougherty U, Mustafi R, Kong J, Deb DK, Zheng H, Bissonnette M, Li YC. Inactivation of the vitamin D receptor in APC(min/+) mice reveals a critical role for the vitamin D receptor in intestinal tumor growth. Int J Cancer 2011; 130:10-9. [PMID: 21328347 DOI: 10.1002/ijc.25992] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 01/31/2011] [Indexed: 12/22/2022]
Abstract
Emerging evidence supports an inhibitory role for vitamin D in colorectal carcinogenesis; however, the mechanism remains unclear. The adenomatous polyposis coli (APC)/β-catenin pathway plays a critical role in colorectal carcinogenesis. The purpose of our study is to explore the interactions of vitamin D and APC/β-catenin pathways in intestinal tumor development. APC(min/+) mice with genetic inactivation of the vitamin D receptor (VDR) were generated through breeding. Intestinal tumorigenesis was compared between APC(min/+) and APC(min/+) VDR(-/-) mice at different ages. No differences were seen in the number of small intestinal and colonic tumors between APC(min/+) and APC(min/+) VDR(-/-) mice aged 3, 4, 6 and 7 months. The size of the tumors, however, was significantly increased in APC(min/+) VDR(-/-) mice in all age groups. Immunostaining showed significant increases in β-catenin, cyclin D1, phosphorylated Stat-3 and MSH-2 levels and decreases in Stat-1 in APC(min/+) VDR(-/-) tumors compared to APC(min/+) tumors. These observations suggest that VDR signaling inhibits tumor growth rather than tumor initiation in the intestine. Thus, the increased tumor burden in APC(min/+) VDR(-/-) mice is likely due to the loss of the growth-inhibiting effect of VDR. This study provides strong evidence for the in vivo relevance of the interaction demonstrated in vitro between the vitamin D and β-catenin signaling pathways in intestinal tumorigenesis.
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Affiliation(s)
- Wei Zheng
- Department of General Surgery, Institute of Clinical Medical Research, Hunan Provincial People's Hospital, Changsha, Hunan, China
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Dougherty U, Cerasi D, Taylor I, Kocherginsky M, Tekin U, Badal S, Aluri L, Sehdev A, Cerda S, Mustafi R, Delgado J, Joseph L, Zhu H, Hart J, Threadgill D, Fichera A, Bissonnette M. Epidermal growth factor receptor is required for colonic tumor promotion by dietary fat in the azoxymethane/dextran sulfate sodium model: roles of transforming growth factor-{alpha} and PTGS2. Clin Cancer Res 2009; 15:6780-9. [PMID: 19903783 DOI: 10.1158/1078-0432.ccr-09-1678] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Colon cancer is a major cause of cancer deaths. Dietary factors contribute substantially to the risk of this malignancy. Western-style diets promote development of azoxymethane-induced colon cancer. Although we showed that epidermal growth factor receptors (EGFR) controlled azoxymethane tumorigenesis in standard fat conditions, the role of EGFR in tumor promotion by high dietary fat has not been examined. EXPERIMENTAL DESIGN A/J x C57BL6/J mice with wild-type Egfr (Egfr(wt)) or loss-of-function waved-2 Egfr (Egfr(wa2)) received azoxymethane followed by standard (5% fat) or western-style (20% fat) diet. As F(1) mice were resistant to azoxymethane, we treated mice with azoxymethane followed by one cycle of inflammation-inducing dextran sulfate sodium to induce tumorigenesis. Mice were sacrificed 12 weeks after dextran sulfate sodium. Tumors were graded for histology and assessed for EGFR ligands and proto-oncogenes by immunostaining, Western blotting, and real-time PCR. RESULTS Egfr(wt) mice gained significantly more weight and had exaggerated insulin resistance compared with Egfr(wa2) mice on high-fat diet. Dietary fat promoted tumor incidence (71.2% versus 36.7%; P < 0.05) and cancer incidence (43.9% versus 16.7%; P < 0.05) only in Egfr(wt) mice. The lipid-rich diet also significantly increased tumor and cancer multiplicity only in Egfr(wt) mice. In tumors, dietary fat and Egfr(wt) upregulated transforming growth factor-alpha, amphiregulin, CTNNB1, MYC, and CCND1, whereas PTGS2 was only increased in Egfr(wt) mice and further upregulated by dietary fat. Notably, dietary fat increased transforming growth factor-alpha in normal colon. CONCLUSIONS EGFR is required for dietary fat-induced weight gain and tumor promotion. EGFR-dependent increases in receptor ligands and PTGS2 likely drive diet-related tumor promotion.
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Affiliation(s)
- Urszula Dougherty
- Departments of Medicine, Health Studies, Surgery, and Pathology, University of Chicago, Chicago, Illinois , USA
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Delgado JS, Mustafi R, Yee J, Cerda S, Chumsangsri A, Dougherty U, Lichtenstein L, Fichera A, Bissonnette M. Sorafenib triggers antiproliferative and pro-apoptotic signals in human esophageal adenocarcinoma cells. Dig Dis Sci 2008; 53:3055-64. [PMID: 18512153 DOI: 10.1007/s10620-008-0294-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2008] [Accepted: 04/10/2008] [Indexed: 02/05/2023]
Abstract
BACKGROUND AND PURPOSE Current therapies offer scant benefit to patients with advanced esophageal adenocarcinoma. We investigated the effects of Sorafenib, a multifunctional kinase inhibitor, on several growth regulatory pathways that control cell growth and survival in SEG-1 cells derived from Barrett's adenocarcinoma. METHODS SEG-1 cells were exposed to acidified medium or taurocholic acid, with and without pre-incubation with Sorafenib. Cyclin D1 and E, c-Myc, and Bcl-2 expression levels as well as STAT3 activations were determined by Western blotting. Cyclin D1 mRNA was measured by real-time PCR. Apoptosis was assessed by TUNEL assay. RESULTS Sorafenib significantly inhibited SEG-1 cell proliferation stimulated by acid or bile acid treatments and reduced cell survival. This drug significantly reduced the up-regulations of cyclin D1, cyclin E, c-Myc, and Bcl-2 as well as the activation of STAT3 in SEG-1 cells. CONCLUSIONS These results support a rational basis for future clinical studies to assess the therapeutic benefit of Sorafenib in esophageal adenocarcinoma.
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Affiliation(s)
- Jorge-Shmuel Delgado
- Section of Gastroenterology, Department of Medicine, The University of Chicago Medical Center, MC 4076. 5841 S. Maryland Ave, Chicago, IL, 60637, USA.
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Khare S, Mustafi R, Cerda S, Yuan W, Jagadeeswaran S, Dougherty U, Tretiakova M, Samarel A, Cohen G, Wang J, Moore C, Wali R, Holgren C, Joseph L, Fichera A, Li YC, Bissonnette M. Ursodeoxycholic acid suppresses Cox-2 expression in colon cancer: roles of Ras, p38, and CCAAT/enhancer-binding protein. Nutr Cancer 2008; 60:389-400. [PMID: 18444174 DOI: 10.1080/01635580701883003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
In the azoxymethane (AOM) model of experimental rodent colon cancer, cholic acid and its colonic metabolite deoxycholic acid (DCA) strongly promote tumorigenesis. In contrast, we showed that ursodeoxycholic acid (UDCA), a low abundance bile acid, inhibited AOM tumorigenesis. Dietary UDCA also blocked the development of tumors with activated Ras and suppressed cyclooxygenase-2 (Cox-2) upregulation in AOM tumors. In this study, we compared the effect of dietary supplementation with tumor-promoting cholic acid to chemopreventive UDCA on Cox-2 expression in AOM tumors. Cholic acid enhanced Cox-2 upregulation in AOM tumors, whereas UDCA inhibited this increase and concomitantly decreased CCAAT/enhancer binding protein beta (C/EBPbeta), a transcriptional regulator of Cox-2. In HCA-7 colon cancer cells, DCA activated Ras and increased C/EBPbeta and Cox-2 by a mechanism requiring the mitogen-activated protein kinase p38. UDCA inhibited DCA-induced p38 activation and decreased C/EBPbeta and Cox-2 upregulation. Using transient transfections, UDCA inhibited Cox-2 promoter and C/EBP reporter activation by DCA. Transfection with dominant-negative (17)N-Ras abolished DCA-induced p38 activation and C/EBPbeta and Cox-2 upregulation. Taken together, these studies have identified a transcriptional pathway regulating Cox-2 expression involving Ras, p38, and C/EBPbeta that is inhibited by UDCA. These signal transducers are novel targets of UDCA's chemopreventive actions.
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Affiliation(s)
- Sharad Khare
- Department of Medicine, Loyola University Medical Center, Maywood, Illinois 60153, USA.
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Keswani RN, Chumsangsri A, Mustafi R, Delgado J, Cohen EEW, Bissonnette M. Sorafenib inhibits MAPK-mediated proliferation in a Barrett's esophageal adenocarcinoma cell line. Dis Esophagus 2008; 21:514-21. [PMID: 18840136 DOI: 10.1111/j.1442-2050.2007.00799.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Esophageal adenocarcinoma continues to rise in incidence. Despite recognition of Barrett's metaplasia as the histological precursor, prognosis remains poor. The mitogen-activated protein kinases (MAPK) pathway is activated in Barrett's-associated dysplasia and adenocarcinoma and this activation is, in part, due to acid and bile acid reflux. We investigated the effects of sorafenib, an orally active Raf-inhibitor, on acid and bile acid-stimulated growth and signaling in SEG-1 cells, derived from a Barrett's esophageal cancer. SEG-1 cells were pretreated with sorafenib or vehicle and subsequently stimulated with acid or bile acid. MAPK signals, including phospho-ERK and phospho-p38, as well as cyclin D1 expression were assessed by Western blotting. Cell proliferation was measured by WST-1 colorimetric assay. Acid (pH 3.0-4.0) and bile acid (taurocholate 50-100 micromol/L) activated ERK and p38. Acid and bile acid exposure also increased levels of cyclin D1, a G1 to S cell cycle regulator. Furthermore, acid and taurocholate exposure increased cell proliferation. Sorafenib abrogated MAPK activation and cyclin D1 up-regulation and significantly inhibited cell growth. In summary, sorafenib inhibits acid or bile acid-stimulated Barrett's esophageal cancer cell proliferation by a mechanism involving the MAPK pathway. Our results suggest that sorafenib might be useful in the management of Barrett's-associated dysplasia and adenocarcinoma. These findings provide a foundation for in vivo studies to assess the efficacy of sorafenib in Barrett's-related neoplasia.
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Affiliation(s)
- R N Keswani
- Department of Medicine, Section of Gastroenterology, University of Chicago, Chicago, Illinois, USA
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21
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Sun J, Mustafi R, Cerda S, Chumsangsri A, Xia YR, Li YC, Bissonnette M. Lithocholic acid down-regulation of NF-kappaB activity through vitamin D receptor in colonic cancer cells. J Steroid Biochem Mol Biol 2008; 111:37-40. [PMID: 18515093 PMCID: PMC2587242 DOI: 10.1016/j.jsbmb.2008.01.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 01/14/2008] [Indexed: 12/20/2022]
Abstract
Lithocholic acid (LCA), a secondary bile acid, is a vitamin D receptor (VDR) ligand. 1,25-Dihydroxyvitamin D(3) (1,25(OH)(2)D(3)), the hormonal form of vitamin D, is involved in the anti-inflammatory action through VDR. Therefore, we hypothesize that LCA acts like 1,25(OH)(2)D(3) to drive anti-inflammatory signals. In present study, we used human colonic cancer cells to assess the role of LCA in regulation of the pro-inflammatory NF-kappaB pathway. We found that LCA treatment increased VDR levels, mimicking the effect of 1,25(OH)(2)D(3). LCA pretreatment inhibited the IL-1beta-induced IkappaBalpha degradation and decreased the NF-kappaB p65 phosphorylation. We also measured the production of IL-8, a well-known NF-kappaB target gene, as a read-out of the biological effect of LCA expression on NF-kappaB pathway. LCA significantly decreased IL-8 secretion induced by IL-1beta. These LCA-induced effects were very similar to those of 1,25(OH)(2)D(3.) Thus, LCA recapitulated the effects of 1,25(OH)(2)D(3) on IL-1beta stimulated cells. Mouse embryonic fibroblast (MEF) cells lacking VDR have intrinsically high NF-kappaB activity. LCA pretreatment was not able to prevent TNFalpha-induced IkappaBalpha degradation in MEF VDR (-/-), whereas LCA stabilized IkappaBalpha in MEF VDR (+/-) cells. Collectively, our data indicated that LCA activated the VDR to block inflammatory signals in colon cells.
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Affiliation(s)
- Jun Sun
- Department of Medicine, Gastroenterology and Hepatology, University of Rochester, Rochester, NY 14642, USA.
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22
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Dougherty U, Sehdev A, Cerda S, Mustafi R, Little N, Yuan W, Jagadeeswaran S, Chumsangsri A, Delgado J, Tretiakova M, Joseph L, Hart J, Cohen EEW, Aluri L, Fichera A, Bissonnette M. Epidermal growth factor receptor controls flat dysplastic aberrant crypt foci development and colon cancer progression in the rat azoxymethane model. Clin Cancer Res 2008; 14:2253-62. [PMID: 18413814 DOI: 10.1158/1078-0432.ccr-07-4926] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE Colonic carcinogenesis deranges growth-regulating epidermal growth factor receptors (EGFR). We previously showed that EGFR signals were up-regulated in human aberrant crypt foci (ACF), putative colon cancer precursors. The azoxymethane model of colon cancer recapitulates many aspects of human colonic tumors. Recent studies indicate that flat dysplastic ACF with increased beta-catenin are tumor precursors in this model. We asked, therefore, if EGFR signals are required for flat dysplastic ACF development and cancer progression. EXPERIMENTAL DESIGN Rats received azoxymethane or saline, and standard chow or chow supplemented with gefitinib, an EGFR inhibitor, for 44 weeks. EGFR signals were quantified in normal colon, flat ACF, and tumors by computerized analysis of immunostains and Western blots. K-ras mutations were assessed by PCR and mRNA for egfr ligands by quantitative real-time PCR. RESULTS EGFR inhibition with gefitinib decreased the incidence of flat dysplastic ACF from 66% to 36% and tumors from 71% to 22% (P < 0.05). This inhibitor also reduced the overexpressions of cyclin D1 and Cox-2 in flat ACF. Furthermore, in flat ACF, EGFR blockade decreased the up-regulation of c-Jun, FosB, phosphorylated active signal transducers and activators of transcription 3, and CCAAT/enhancer binding protein-beta, potential regulators of cyclin D1 and Cox-2. In colonic tumors, EGFR blockade significantly decreased angiogenesis, proliferation, and progression while also increasing apoptosis (P < 0.05). Gefitinib also inhibited the activations of extracellular signal-regulated kinase, Src, and AKT pathways in tumors. CONCLUSIONS We have shown for the first time that EGFR promotes the development of flat dysplastic ACF and the progression of malignant colonic tumors. Furthermore, we have mechanistically identified several transcription factors and their targets as EGFR effectors in colonic carcinogenesis.
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Affiliation(s)
- Urszula Dougherty
- Department of Medicine, University of Chicago Hospitals and Clinics, Chicago, IL 60637, USA
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Fichera A, Little N, Dougherty U, Mustafi R, Cerda S, Li YC, Delgado J, Arora A, Campbell LK, Joseph L, Hart J, Noffsinger A, Bissonnette M. A vitamin D analogue inhibits colonic carcinogenesis in the AOM/DSS model. J Surg Res 2007; 142:239-45. [PMID: 17574271 DOI: 10.1016/j.jss.2007.02.038] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2007] [Revised: 02/20/2007] [Accepted: 02/26/2007] [Indexed: 02/08/2023]
Abstract
BACKGROUND The azoxymethane (AOM) model recapitulates many features of human colon cancer, lacking an inflammatory component. Dextran sulfate sodium (DSS) induces colitis and promotes AOM-induced colon cancer in mice. Vitamin D analogues are anti-inflammatory and chemopreventive in models of colon cancer. Our aim was to evaluate the anti-inflammatory and chemopreventive efficacy of the vitamin D analogue Ro26-2198 in the AOM/DSS model and in vitro in HCA-7 colon cancer cells. MATERIALS AND METHODS A/J mice received Ro26-2198 (0.01 microg/kg body wt/day x 28 days) or vehicle by mini-osmotic pump. Animals were treated with a single dose of AOM (5 mg/kg body wt) or vehicle 1 week after pump insertion. Mice received 3% DSS or water x 7 days beginning week 3. Animals were sacrificed after 8 weeks and colon segments were fixed in formalin or flash-frozen. Hematoxylin and eosin colonic sections were examined for dysplasia and colonic lysates were assessed for c-Myc, cyclooxygenase 2, and phospho-(active) extracellular signal regulated kinase (ERK) by Western blotting. For in vitro studies, HCA-7 cells were treated with Ro26-2198 followed by interleukin-1beta (IL-1beta). Proliferation was measured by WST-1 assay. RESULTS Ro26-2198 delayed the onset of clinical colitis. Several dysplastic foci were present in the AOM/DSS group; none were found in the Ro26-2198 group. Compared with control, AOM/DSS significantly increased c-Myc (15-fold), cyclooxygenase 2 (COX-2) (2.5-fold), and pERK (10-fold), and Ro26-2198 abolished these increases. In vitro, Ro26-2198 inhibited IL-1beta-induced ERK activation and COX-2 induction and decreased HCA-7 cell proliferation. CONCLUSIONS Ro26-2198 inhibited proliferative (ERK, c-Myc) and pro-inflammatory (COX-2) signals and progression to dysplasia, suggesting chemopreventive efficacy in this model of colitis-associated carcinogenesis.
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Affiliation(s)
- Alessandro Fichera
- Department of Surgery, University of Chicago, Chicago, Illinois 60637, USA.
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Fichera A, Little N, Jagadeeswaran S, Dougherty U, Sehdev A, Mustafi R, Cerda S, Yuan W, Khare S, Tretiakova M, Gong C, Tallerico M, Cohen G, Joseph L, Hart J, Turner JR, Bissonnette M. Epidermal growth factor receptor signaling is required for microadenoma formation in the mouse azoxymethane model of colonic carcinogenesis. Cancer Res 2007; 67:827-35. [PMID: 17234795 PMCID: PMC2705749 DOI: 10.1158/0008-5472.can-05-3343] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Colonic carcinogenesis involves the progressive dysregulation of homeostatic mechanisms that control growth. The epidermal growth factor (EGF) receptor (EGFR) regulates colonocyte growth and differentiation and is overexpressed in many human colon cancers. A requirement for EGFR in colonic premalignancy, however, has not been shown. In the current study, we used a specific EGFR antagonist, gefitinib, to investigate this role of the receptor in azoxymethane colonic premalignancy. The azoxymethane model shares many clinical, histologic, and molecular features of human colon cancer. Mice received azoxymethane i.p. (5 mg/kg/wk) or saline for 6 weeks. Animals were also gavaged with gefitinib (10 mg/kg body weight) or vehicle (DMSO) thrice weekly for 18 weeks, a dose schedule that inhibited normal receptor activation by exogenous EGF. Compared with control colonocytes [bromodeoxyuridine (BrdUrd), 2.2+/-1.2%], azoxymethane significantly increased proliferation (BrdUrd, 12.6+/-2.8%), whereas gefitinib inhibited this hyperproliferation (BrdUrd, 6.2+/-4.0%; <0.005). Azoxymethane significantly induced pro-transforming growth factor-alpha (6.4+/-1.3-fold) and increased phospho-(active) EGFR (5.9+/-1.1-fold), phospho-(active) ErbB2 (2.3+/-0.2-fold), and phospho-(active) extracellular signal-regulated kinase (3.3+/-0.4-fold) in premalignant colonocytes. Gefitinib inhibited activations of these kinases by >75% (P<0.05). Gefitinib also significantly reduced the number of large aberrant crypt foci and decreased the incidence of colonic microadenomas from 75% to 33% (P<0.05). Gefitinib concomitantly decreased cell cycle-regulating cyclin D1 and prostanoid biosynthetic enzyme cyclooxygenase-2 in microadenomas, suggesting that these regulators are key targets of EGFR in colonic carcinogenesis. These results show for the first time that EGFR signaling is required for early stages of colonic carcinogenesis. Our findings suggest, moreover, that inhibitors of EGFR might be useful in chemopreventive strategies in individuals at increased risk for colonic malignancies.
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Affiliation(s)
- Alessandro Fichera
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
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25
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Mustafi R, Cerda S, Chumsangsri A, Fichera A, Bissonnette M. Protein Kinase-zeta inhibits collagen I-dependent and anchorage-independent growth and enhances apoptosis of human Caco-2 cells. Mol Cancer Res 2006; 4:683-94. [PMID: 16940160 DOI: 10.1158/1541-7786.mcr-06-0057] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Colonic carcinogenesis is accompanied by abnormalities in multiple signal transduction components, including alterations in protein kinase C (PKC). The expression level of PKC-zeta, an atypical PKC isoform, increases from the crypt base to the luminal surface and parallels crypt cell differentiation in normal colon. In prior studies in the azoxymethane model of colon cancer, we showed that PKC-zeta was down-regulated in rat colonic tumors. In this study, we showed that PKC-zeta is expressed predominantly in colonic epithelial and not stromal cells, and loss of PKC-zeta occurs as early as the adenoma stage in human colonic carcinogenesis. To assess the regulation of growth and differentiation by PKC-zeta, we altered this isoform in human Caco-2 colon cancer cells using stable constitutive or inducible expression vectors, specific peptide inhibitors or small interfering RNA. In ecdysone-regulated transfectants grown on collagen I, ponasterone A significantly induced PKC-zeta expression to 135% of empty vector cells, but did not alter nontargeted PKC isoforms. This up-regulation was accompanied by a 2-fold increase in basal and 4-fold increase in insulin-stimulated PKC-zeta biochemical activity. Furthermore, PKC-zeta up-regulation caused >50% inhibition of cell proliferation on collagen I (P < 0.05). Increased PKC-zeta also significantly enhanced Caco-2 cell differentiation, nearly doubling alkaline phosphatase activity, while inducing a 3-fold increase in the rate of apoptosis (P < 0.05). In contrast, knockdown of this isoform by small interfering RNA or kinase inhibition by myristoylated pseudosubstrate significantly and dose-dependently increased Caco-2 cell growth on collagen I. In transformation assays, constitutively up-regulated wild-type PKC-zeta significantly inhibited Caco-2 cell growth in soft agar, whereas a kinase-dead mutant caused a 3-fold increase in soft agar growth (P < 0.05). Taken together, these studies indicate that PKC-zeta inhibits colon cancer cell growth and enhances differentiation and apoptosis, while inhibiting the transformed phenotype of these cells. The observed down-regulation of this growth-suppressing PKC isoform in colonic carcinogenesis would be predicted to contribute to tumorigenesis.
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Affiliation(s)
- Reba Mustafi
- Department of Medicine, The University of Chicago Hospitals and Clinics, MC 4076, 5841 South Maryland Avenue, Chicago, IL 60637, USA
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26
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Cohen G, Mustafi R, Chumsangsri A, Little N, Nathanson J, Cerda S, Jagadeeswaran S, Dougherty U, Joseph L, Hart J, Yerian L, Tretiakova M, Yuan W, Obara P, Khare S, Sinicrope FA, Fichera A, Boss GR, Carroll R, Bissonnette M. Epidermal growth factor receptor signaling is up-regulated in human colonic aberrant crypt foci. Cancer Res 2006; 66:5656-64. [PMID: 16740703 DOI: 10.1158/0008-5472.can-05-0308] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Aberrant crypt foci (ACF) are collections of abnormal colonic crypts with heterogeneous molecular and pathologic characteristics. Large and dysplastic ACF are putative precursors of colon cancer with neoplastic risk related to increased proliferation. In this study, we examined the role of epidermal growth factor receptor (EGFR) signaling in regulating ACF proliferation. Using magnification chromoendoscopy, we collected large ACF with endoscopic features of dysplasia and separately biopsied adjacent mucosa. Transcript levels were measured by real-time PCR, proteins were assessed by Western blotting, and levels were expressed as fold changes of adjacent mucosa. K-ras and B-Raf mutations were assessed by PCR and Ras activation by the ratio Ras-GTP / (Ras-GTP + Ras-GDP). At the RNA level, 38% of ACF were hyperproliferative, with proliferating cell nuclear antigen (PCNA) mRNA >/=2-fold of adjacent mucosa. Hyperproliferative ACF had significantly increased mRNA levels of EGFR (6.0 +/- 1.7-fold), transforming growth factor-alpha (14.4 +/- 5.0-fold), heparin-binding EGF-like growth factor (4.5 +/- 1.4-fold), cyclin D1 (4.6 +/- 0.7-fold), and cyclooxygenase-2 (COX-2; 9.3 +/- 4.2-fold; P < 0.05). At the protein level, 46% of ACF were hyperproliferative (PCNA, 3.2 +/- 1.2-fold). In hyperproliferative ACF, 44% possessed significant increases in four EGFR signaling components: EGFR (9.5 +/- 1.3-fold), phosphoactive ErbB2 (2.6 +/- 0.4-fold), phosphoactive extracellular signal-regulated kinase (3.7 +/- 1.1-fold), and cyclin D1 (3.4 +/- 0.8-fold; P < 0.05). Ras was activated in 46% of ACF (3.2 +/- 0.4-fold; P < 0.05), but K-ras mutations were present in only 7% of ACF. In contrast to COX-2 mRNA, the protein was not increased in hyperproliferative ACF. In summary, we have shown that ACF with up-regulated PCNA possess increased EGFR signaling components that likely contribute to the enhanced proliferative state of dysplastic-appearing ACF.
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Affiliation(s)
- Greg Cohen
- Department of Medicine, University of Chicago, Illinois, USA
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27
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Cerda SR, Mustafi R, Little H, Cohen G, Khare S, Moore C, Majumder P, Bissonnette M. Protein kinase C delta inhibits Caco-2 cell proliferation by selective changes in cell cycle and cell death regulators. Oncogene 2006; 25:3123-38. [PMID: 16434969 DOI: 10.1038/sj.onc.1209360] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PKC-delta is a serine/threonine kinase that mediates diverse signal transduction pathways. We previously demonstrated that overexpression of PKC-delta slowed the G1 progression of Caco-2 colon cancer cells, accelerated apoptosis, and induced cellular differentiation. In this study, we further characterized the PKC-delta dependent signaling pathways involved in these tumor suppressor actions in Caco-2 cells overexpressing PKC-delta using a Zn2+ inducible expression vector. Consistent with a G1 arrest, increased expression of PKC-delta caused rapid and significant downregulation of cyclin D1 and cyclin E proteins (50% decreases, P<0.05), while mRNA levels remained unchanged. The PKC agonist, phorbol 12-myristate 13-acetate (TPA, 100 nM, 4 h), induced two-fold higher protein and mRNA levels of p21(Waf1), a cyclin-dependent kinase (cdk) inhibitor in PKC-delta transfectants compared with empty vector (EV) transfected cells, whereas the PKC-delta specific inhibitor rottlerin (3 microM) or knockdown of this isoenzyme with specific siRNA oligonucleotides blocked p21(Waf1) expression. Concomitantly, compared to EV control cells, PKC-delta upregulation decreased cyclin D1 and cyclin E proteins co-immunoprecipitating with cdk6 and cdk2, respectively. In addition, overexpression of PKC-delta increased binding of cdk inhibitor p27(Kip1) to cdk4. These alterations in cyclin-cdks and their inhibitors are predicted to decrease G1 cyclin kinase activity. As an independent confirmation of the direct role PKC-delta plays in cell growth and cell cycle regulation, we knocked down PKC-delta using specific siRNA oligonucleotides. PKC-delta specific siRNA oligonucleotides, but not irrelevant control oligonucleotides, inhibited PKC-delta protein by more than 80% in Caco-2 cells. Moreover, PKC-delta knockdown enhanced cell proliferation ( approximately 1.4-2-fold, P<0.05) and concomitantly increased cyclin D1 and cyclin E expression ( approximately 1.7-fold, P<0.05). This was a specific effect, as nontargeted PKC-zeta was not changed by PKC-delta siRNA oligonucleotides. Consistent with accelerated apoptosis in PKC-delta transfectants, compared to EV cells, PKC-delta upregulation increased proapoptotic regulator Bax two-fold at mRNA and protein levels, while antiapoptotic Bcl-2 protein was decreased by 50% at a post-transcriptional level. PKC-delta specific siRNA oligonucleotides inhibited Bax protein expression by more than 50%, indicating that PKC-delta regulates apoptosis through Bax. Taken together, these results elucidate two critical mechanisms regulated by PKC-delta that inhibit cell cycle progression and enhance apoptosis in colon cancer cells. We postulate these antiproliferative pathways mediate an important tumor suppressor function for PKC-delta in colonic carcinogenesis.
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Affiliation(s)
- S R Cerda
- Department of Medicine, Division of Gastroenterology, University of Chicago, Chicago, IL 60637, USA.
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28
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Cerda SR, Bissonnette M, Scaglione-Sewell B, Lyons MR, Khare S, Mustafi R, Brasitus TA. PKC-delta inhibits anchorage-dependent and -independent growth, enhances differentiation, and increases apoptosis in CaCo-2 cells. Gastroenterology 2001; 120:1700-12. [PMID: 11375951 DOI: 10.1053/gast.2001.24843] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Previous studies showed decreased protein kinase C (PKC)-delta expression in azoxymethane-induced rat and sporadic human colonic tumors. To elucidate the role of PKC-delta on the neoplastic phenotype of human colon cancer cells, we established stable transfectants of this isoenzyme in CaCo-2 cells. METHODS Human PKC-delta complementary DNA was subcloned into 2 distinct metallothionein-regulated expression vectors. Polyclonal populations of PKC-delta transfectants were characterized by Western blotting. PKC-delta activity was measured in situ using a PKC-delta-specific substrate. Proliferation was determined by Coulter counter, and cell cycle distribution was analyzed by flow cytometry. In vitro transformation was assessed by growth in soft agar and differentiation by changes in alkaline phosphatase and sucrase isomaltase. Apoptosis was evaluated by 4',6-diamidino-2-phenylindole dihydrochloride and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling staining. RESULTS In the presence of Zn(2+), PKC-delta transfectants expressed a 4-fold increase in the protein and a 2-fold increase in activity of PKC-delta. PKC-delta transfectants exhibited a 30% decrease (P < 0.05) in cell growth and an enhanced differentiation phenotype. Increased PKC-delta expression induced a significant G0/G1 arrest, inhibited anchorage-independent growth (50%, P < 0.05), and caused a 2-fold increase in apoptosis (P < 0.05). CONCLUSIONS Our studies show that increased expression of PKC-delta inhibits anchorage-dependent and -independent growth, while inducing cellular differentiation and limiting survival of this human colon cancer cell line.
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Affiliation(s)
- S R Cerda
- Division of Gastroenterology, Department of Medicine, University of Chicago, Chicago, Illinois, USA
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29
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Wali RK, Skarosi S, Hart J, Zhang Y, Dolan ME, Moschel RC, Nguyen L, Mustafi R, Brasitus TA, Bissonnette M. Inhibition of O(6)-methylguanine-DNA methyltransferase increases azoxymethane-induced colonic tumors in rats. Carcinogenesis 1999; 20:2355-60. [PMID: 10590233 DOI: 10.1093/carcin/20.12.2355] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Azoxymethane (AOM) causes O(6)-methylguanine adduct formation which leads to G-->A transitions. Their repair is carried out by O(6)-methylguanine-DNA methyltransferase (MGMT). To evaluate the importance of this repair event in AOM-induced carcinogenesis, we examined the effect of O(6)-benzylguanine (BG), a potent inhibitor of MGMT, on colonic tumor development. Rats were treated weekly for 2 weeks at 0 and 24 h with BG (60 mg/kg body wt i.p.) or vehicle (40% polyethylene glycol, PEG-400), followed 2 h after the first dose of BG with AOM (15 mg/kg body wt) or vehicle (saline) i.p. Rats were killed 35 weeks later and tumors harvested and DNA extracted. In the AOM-treated groups, BG caused a significant increase in tumor incidence with tumors in 65.9%, versus 30.8% in the AOM/PEG-treated group (P < 0.05). In the BG/AOM group there was also a significant increase in tumor multiplicity, with 2.3 tumors/tumor-bearing rat, versus 1.6 tumors/tumor- bearing rat in the AOM/PEG group (P < 0.05). Since O(6)-methylguanine adducts can cause activating mutations in the K-ras and beta-catenin genes, we examined the effects of BG on these mutations. In the BG group there were seven mutations in codon 12 or 13 of exon 1 of the K-ras gene in 51 tumors examined, compared with no K-ras mutations in 17 tumors analyzed in the AOM/PEG group (P = 0.12). In the BG/AOM group there were 10 mutations in exon 3 of the beta-catenin gene among 48 tumors evaluated, compared with six mutations in 16 tumors analyzed in the PEG/AOM group (P = 0.16). In summary, MGMT inhibition increases AOM-induced colonic tumor incidence and multiplicity in rats.
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Affiliation(s)
- R K Wali
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
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30
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Schwartz JL, Mustafi R, Hughes A, DeSombre ER. DNA and chromosome breaks induced by iodine-123-labeled estrogen in Chinese hamster ovary cells. Radiat Res 1996; 146:151-8. [PMID: 8693065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The effects of the Auger electron-emitting isotope 123I, covalently bound to estrogen, on DNA single- and double-strand breakage and on chromosome breakage was determined in estrogen receptor-positive Chinese hamster ovary (CHO-ER) cells. Exposure to the 123I-labeled estrogen induced both single- and double-strand breaks with a ratio of single- to double-strand breaks of 2.8. The corresponding ratio with 60Co gamma rays was 15.6. The dose response was biphasic, suggesting either that receptor sites are saturated at high doses, or that there is a nonrandom distribution of breaks induced by the 123I-labeled estrogen. The 123I-labeled estrogen treatment induced chromosome aberrations with an efficiency of about 1 aberration for each 1000 disintegrations per cell. This corresponds to the mean lethal dose of 123I-labeled estrogen for these cells, suggesting that the lethal event induced by the Auger electron emitter bound to estrogen is a chromosome aberration. Most of the chromosome-type aberrations were dicentrics and rings, suggesting that 123I-labeled estrogen-induced chromosome breaks are rejoined. The F ratio, the ratio of dicentrics to centric rings, was 5.8 +/- 1.7, which is similar to that seen with high-LET radiations. Our results suggest that 123I bound to estrogen is an efficient clastogenic agent, the cytotoxic damage produced by 123I bound to estrogen is very like damage induced by high-LET radiation, and the 123I in the estrogen receptor-DNA complex is probably in proximity to the sugar-phosphate backbone of the DNA.
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Affiliation(s)
- J L Schwartz
- Center for Mechanistic Biology and Biotechnology, Argonne National Laboratory, Illinois 60439-4833, USA
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Schwartz JL, Mustafi R, Hughes A, DeSombre ER. DNA and Chromosome Breaks Induced by Iodine- 123-Labeled Estrogen in Chinese Hamster Ovary Cells. Radiat Res 1996. [DOI: 10.2307/3579587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schwartz JL, Mustafi R, Beckett MA, Weichselbaum RR. DNA double-strand break rejoining rates, inherent radiation sensitivity and human tumour response to radiotherapy. Br J Cancer 1996; 74:37-42. [PMID: 8679455 PMCID: PMC2074601 DOI: 10.1038/bjc.1996.312] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The relationship between DNA double-strand break rejoining rates, inherent radiation sensitivity and tumour response to radiation therapy was determined for a group of 25 squamous cell carcinoma (SCC) and eight sarcoma (SAR) tumours. DNA double-strand break frequencies were measured by neutral filter elution in first passage following explant tumour samples after in vitro exposure to 100 Gy of 60Co gamma-rays. There was no significant difference between SCC and SAR tumour cells in their sensitivity to break induction, but in a 1 h time period SAR tumour cells rejoined significantly fewer breaks than SCC tumour cells, consistent with the greater sensitivity of SAR and suggesting that differences in rates of break rejoining account for the different distributions of radiosensitivities seen when different tumour types are compared. The percentage of breaks rejoined in 1 h in these tumour samples correlated well with D(o) and with the beta component of the survival curve, measured in vitro by clonogenic assay in tumour cell lines established from the tumour samples, but not with SF2 or the alpha component of the survival curve. The rates of DNA double-strand break rejoining therefore appear to influence the exponential portion of survival curves and probably the interactions between breaks. The percentage of breaks rejoined in 1 h was higher in SCC tumours that subsequently failed radiotherapy and, although the differences were not significant, they suggest that rates of break rejoining are an important component of tumour response to radiation therapy.
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Affiliation(s)
- J L Schwartz
- Center for Mechanistic Biology and Biotechnology, Argonne National Laboratory, Illinois 60439-4833, USA
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Becker MA, Smith PR, Taylor W, Mustafi R, Switzer RL. The genetic and functional basis of purine nucleotide feedback-resistant phosphoribosylpyrophosphate synthetase superactivity. J Clin Invest 1995; 96:2133-41. [PMID: 7593598 PMCID: PMC185862 DOI: 10.1172/jci118267] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The genetic and functional basis of phosphoribosylpyrophosphate synthetase (PRS) superactivity associated with purine nucleotide inhibitor-resistance was studied in six families with this X chromosome-linked purine metabolic and neurodevelopmental disorder. Cloning and sequencing of PRS1 and PRS2 cDNAs, derived from fibroblast total RNA of affected male patients by reverse transcription and PCR amplification, demonstrated that each PRS1 cDNA contained a distinctive single base substitution predicting a corresponding amino acid substitution in the PRS1 isoform. Overall, the array of substitutions encompassed a substantial portion of the translated sequence of PRS1 cDNA. Plasmid-mediated expression of variant PRS1 cDNAs in Escherichia coli BL21 (DE3/pLysS) yielded recombinant mutant PRS1s, which, in each case, displayed a pattern and magnitude of purine nucleoside diphosphate inhibitor-resistance comparable to that found in cells of the respective patient. Kinetic analysis of recombinant mutant PRS1s showed that widely dispersed point mutations in the X chromosome-linked PRPS1 gene encoding the PRS1 isoform result in alteration of the allosteric mechanisms regulating both enzyme inhibition by purine nucleotides and activation by inorganic phosphate. The functional consequences of these mutations provide a tenable basis for the enhanced production of phosphoribosylpyrophosphate, purine nucleotides, and uric acid that are the biochemical hallmarks of PRS superactivity.
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Affiliation(s)
- M A Becker
- Department of Medicine, University of Chicago, Illinois 60637, USA
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Abstract
The effect of the DNA polymerase inhibitors adenine 9-beta-arabinofuranoside (ara-A), cytosine 1-beta-arabinofuranoside (ara-C), and aphidicolin on X-radiation sensitivity was studied in a group of exponentially growing squamous cell carcinoma cell lines. The tumour cell lines varied in radiation sensitivity, with D0 (radiation sensitivity) values ranging from 1.0 to 3.9 Gy. The addition of non-toxic concentrations of ara-A 30 min before irradiation and removal 30 min after irradiation potentiated cell killing in five of eight cell lines. Four of these five responsive cell lines were relatively radioresistant lines, having D0 > 2.0 Gy. One of the cell lines was more radiosensitive (D0 = 1.4 Gy). Ara-A was also effective in potentiating killing in the radioresistant cell lines even when added 60 min after irradiation. Pre- or post-treatment with ara-A had no effect on X-ray sensitivity of the other three relatively sensitive cell lines (D0 ranging from 1.0 to 1.3 Gy). Both ara-C and aphidicolin were effective in potentiating X-ray sensitivity in JSQ-3, a relatively resistant cell line that was sensitized by ara-A treatment, but they had no effect on the X-ray sensitivity of SCC-61, a relatively radiosensitive cell line that was insensitive to ara-A effects on X-ray response. At the concentrations used, the polymerase inhibitors were equally effective in inhibiting DNA synthesis.
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Affiliation(s)
- R Mustafi
- Department of Radiation and Cellular Oncology, University of Chicago, Illinois 60637
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Schwartz JL, Moan E, Mustafi R, Fink L, Yasui LS. Faster rates of DNA unwinding under alkaline conditions in xrs-5 cells may reflect chromatin structure alterations. Mutat Res 1992; 282:13-7. [PMID: 1374151 DOI: 10.1016/0165-7992(92)90067-r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The Chinese hamster ovary (CHO) cell line xrs-5 is a radiation-sensitive mutant isolated from CHO-K1 cells. The radiation sensitivity is associated with a defect in DNA double-strand break rejoining. The DNA alkaline unwinding technique was used to measure the DNA single-strand breakage caused by gamma-rays in xrs-5 and CHO-K1 cells. Greater rates of DNA unwinding were found in xrs-5 cells as compared to CHO-K1. Independent measurement of DNA strand breakage by DNA filter elution or pulsed-field gel electrophoresis failed to show any difference between the two cell lines. The greater rate of unwinding in xrs-5 cells may reflect an alteration in chromosome structure.
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Affiliation(s)
- J L Schwartz
- Biological and Medical Research Division, Argonne National Laboratory, IL 60439
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Hallahan DE, Virudachalam S, Schwartz JL, Panje N, Mustafi R, Weichselbaum RR. Inhibition of Protein Kinases Sensitizes Human Tumor Cells to Ionizing Radiation. Radiat Res 1992. [DOI: 10.2307/3578035] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Hallahan DE, Virudachalam S, Schwartz JL, Panje N, Mustafi R, Weichselbaum RR. Inhibition of protein kinases sensitizes human tumor cells to ionizing radiation. Radiat Res 1992; 129:345-50. [PMID: 1542722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Protein kinase C (PKC) is activated rapidly and transiently following ionizing radiation exposure and is postulated to activate downstream nuclear signal transducers. Inhibition of this enzyme attenuates radiation-mediated expression of the c-jun and Egr-1/zif-268 genes which are associated with cellular proliferation. To investigate further the role of PKC in the radiation response of human tumor cell lines, two human squamous cell carcinoma cell lines, SQ-20B and JSQ-3, were exposed to graded doses of X rays in the presence of staurosporine, sangivamycin, or H7, all PKC inhibitors. The protein kinase inhibitors staurosporine and sangivamycin produced dose-dependent cytotoxicity in cells of the SQ-20B and JSQ-3 cell lines while H7 did not. Nontoxic concentrations of sangivamycin (10 nM) and staurosporine (1 nM), added to cell cultures from 1 to 7 h before X irradiation, enhanced cell killing by radiation in both cell lines. Maximal sensitization of killing occurred when inhibitors were added 1 h prior to irradiation. The enhanced radiation-induced cell killing was not due to any measurable alteration in the induction or rejoining of DNA single- or double-strand breaks as determined by alkaline and neutral filter elution assays. These data suggest that protein kinase activity is important for cell survival following radiation exposure, although the specific role of PKC in radiation responses is unknown.
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Affiliation(s)
- D E Hallahan
- Department of Radiation and Cellular Oncology, University of Chicago, Illinois 60637
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Schwartz JL, Mustafi R, Beckett MA, Czyzewski EA, Farhangi E, Grdina DJ, Rotmensch J, Weichselbaum RR. Radiation-induced DNA double-strand break frequencies in human squamous cell carcinoma cell lines of different radiation sensitivities. Int J Radiat Biol 1991; 59:1341-52. [PMID: 1677380 DOI: 10.1080/09553009114551211] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
DNA neutral (pH 9.6) filter elution was used to measure radiation-induced DNA double-strand break (dsb) frequencies in eight human squamous cell carcinoma cell lines with radiosensitivities (D0) ranging from 1.07 to 2.66 Gy and D values ranging from 1.46 to 4.08 Gy. The elution profiles of unirradiated samples from more radiosensitive cell lines were all steeper in slope than the profiles from resistant cells. The shapes of the dsb induction curves were curvilinear and there was some variability from cell line to cell line in the dose-response for the induction of DNA dsb after exposures to 5-100 Gy 60Co gamma-rays. There was no relation between the shapes of the survival curves and the shapes of the dose-responses for the induction of DNA dsb. At low doses (5-25 Gy), three out of four of the more sensitive cell lines (D less than 2.5 Gy) had larger initial break frequencies than the more resistant lines (D greater than 3.0 Gy). Although the low-dose (5-25 Gy) elution results were variable, they do suggest that DNA neutral elution will detect differences between sensitive and resistant tumour cells in initial DNA dsb frequencies.
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Affiliation(s)
- J L Schwartz
- Division of Biological and Medical Research, Argonne National Laboratory, IL 60439-4833
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Schwartz JL, Mustafi R, Beckett MA, Weichselbaum RR. Prediction of the Radiation Sensitivity of Human Squamous Cell Carcinoma Cells Using DNA Filter Elution. Radiat Res 1990. [DOI: 10.2307/3577650] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Schwartz JL, Mustafi R, Beckett MA, Weichselbaum RR. Prediction of the radiation sensitivity of human squamous cell carcinoma cells using DNA filter elution. Radiat Res 1990; 123:1-6. [PMID: 2371374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Radioresistant tumor cells are found in tumor specimens from patients in whom radiotherapy has failed or whose tumors have recurred after therapy. This suggests that inherent cellular radioresistance may in part underlie the failure of radiotherapy, and therefore determination of the presence of resistant cells within a tumor might be a useful predictor of response to radiation therapy. Most standard clonogenic assays of radiation response are time-consuming, and alternative assays of radiation response are being sought. In an earlier publication (J. L. Schwartz et al., Int. J. Radiat. Oncol. Biol. Phys. 15, 907-912, 1988), we reported that radioresistant human tumor cells rejoin DNA double-strand breaks, as measured by DNA neutral filter elution (pH 9.6), faster than more sensitive cell lines. To determine whether DNA elution might have potential as a rapid predictive assay, we examined the relationship between the rate of DNA double-strand break rejoining and radiosensitivity in nine first-passage-after-explant squamous cell carcinomas under conditions that minimized the influence of nontumor and nonclonogenic cells. The frequency of DNA double-strand breaks measured 1 h after irradiation with 100 Gy 60Co gamma rays was used as an estimate of relative rejoining rate. This number is a reflection of both the initial DNA double-strand break frequency and the amount of repair that occurs in 1 h. The relative break frequency was compared to radiosensitivity as measured by standard clonogenic survival assays in later passages (p3-p14) of these same cells. A significant relationship (r = 0.61, P less than 0.01) was found between break frequency measured in first-passage cells and radiosensitivity measured in later passages, suggesting that the neutral elution assay as described here has some promise as a relatively rapid assay of the radiosensitivity of human tumor cells.
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Affiliation(s)
- J L Schwartz
- Department of Radiation and Cellular Oncology, University of Chicago, Illinois 60637
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