1
|
Wali RK, Bianchi L, Kupfer S, De La Cruz M, Jovanovic B, Weber C, Goldberg MJ, Rodriguez LM, Bergan R, Rubin D, Tull MB, Richmond E, Parker B, Khan S, Roy HK. Prevention of colonic neoplasia with polyethylene glycol: A short term randomized placebo-controlled double-blinded trial. PLoS One 2018; 13:e0193544. [PMID: 29617381 PMCID: PMC5884487 DOI: 10.1371/journal.pone.0193544] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Accepted: 01/02/2018] [Indexed: 11/18/2022] Open
Abstract
Chemoprevention represents an attractive modality against colorectal cancer (CRC) although widespread clinical implementation of promising agents (e.g. aspirin/NSAIDS) have been stymied by both suboptimal efficacy and concerns over toxicity. This highlights the need for better agents. Several groups, including our own, have reported that the over-the-counter laxative polyethylene glycol (PEG) has remarkable efficacy in rodent models of colon carcinogenesis. In this study, we undertook the first randomized human trial to address the role of PEG in prevention of human colonic neoplasia. This was a double-blind, placebo-controlled, three-arm trial where eligible subjects were randomized to 8g PEG-3350 (n = 27) or 17g PEG-3350 (n = 24), or placebo (n = 24; maltodextrin) orally for a duration of six months. Our initial primary endpoint was rectal aberrant crypt foci (ACF) but this was changed during protocol period to rectal mucosal epidermal growth factor receptor (EGFR). Of the 87 patients randomized, 48 completed study primary endpoints and rectal EGFR unchanged PEG treatment. Rectal ACF had a trend suggesting potentially reduction with PEG treatment (pre-post change 1.7 in placebo versus -0.3 in PEG 8+ 17g doses, p = 0.108). Other endpoints (proliferation, apoptosis, expression of SNAIL and E-cadherin), previously noted to be modulated in rodent models, appeared unchanged with PEG treatment in this clinical trial. We conclude that PEG was generally well tolerated with the trial failing to meet primary efficacy endpoints. However, rectal ACFs demonstrated a trend (albeit statistically insignificant) for suppression with PEG. Moreover, all molecular assays including EGFR were unaltered with PEG underscoring issues with lack of translatability of biomarkers from preclinical to clinical trials. This data may provide the impetus for future clinical trials on PEG using more robust biomarkers of chemoprevention. Trial registration: ClinicalTrials.gov NCT00828984
Collapse
Affiliation(s)
- Ramesh K. Wali
- Department of Medicine, Boston University Medical Center, Boston, MA, United States of America
| | - Laura Bianchi
- Department of Medicine, NorthShore University HealthSystem, Evanston, IL, United States of America
| | - Sonia Kupfer
- Department of Medicine, University of Chicago, Chicago, IL, United States of America
| | - Mart De La Cruz
- Department of Medicine, Boston University Medical Center, Boston, MA, United States of America
| | - Borko Jovanovic
- Department of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Christopher Weber
- Department of Medicine, University of Chicago, Chicago, IL, United States of America
| | - Michael J. Goldberg
- Department of Medicine, NorthShore University HealthSystem, Evanston, IL, United States of America
| | - L. M. Rodriguez
- National Cancer Institute, Rockville, MD, United States of America
| | - Raymond Bergan
- Department of Medicine, Oregon Health & Science University, Portland, OR, United States of America
| | - David Rubin
- Department of Medicine, University of Chicago, Chicago, IL, United States of America
| | - Mary Beth Tull
- Department of Medicine, Northwestern University, Chicago, IL, United States of America
| | - Ellen Richmond
- National Cancer Institute, Rockville, MD, United States of America
| | - Beth Parker
- Department of Medicine, Boston University Medical Center, Boston, MA, United States of America
| | - Seema Khan
- Department of Medicine, University of Chicago, Chicago, IL, United States of America
| | - Hemant K. Roy
- Department of Medicine, Boston University Medical Center, Boston, MA, United States of America
- * E-mail:
| |
Collapse
|
2
|
Wali RK, Momi N, Dela Cruz M, Calderwood AH, Stypula-Cyrus Y, Almassalha L, Chhaparia A, Weber CR, Radosevich A, Tiwari AK, Latif B, Backman V, Roy HK. Higher Order Chromatin Modulator Cohesin SA1 Is an Early Biomarker for Colon Carcinogenesis: Race-Specific Implications. Cancer Prev Res (Phila) 2016; 9:844-854. [PMID: 27549371 DOI: 10.1158/1940-6207.capr-16-0054] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 08/08/2016] [Indexed: 12/18/2022]
Abstract
Alterations in high order chromatin, with concomitant modulation in gene expression, are one of the earliest events in the development of colorectal cancer. Cohesins are a family of proteins that modulate high-order chromatin, although the role in colorectal cancer remains incompletely understood. We, therefore, assessed the role of cohesin SA1 in colorectal cancer biology and as a biomarker focusing in particular on the increased incidence/mortality of colorectal cancer among African-Americans. Immunohistochemistry on tissue arrays revealed dramatically decreased SA1 expression in both adenomas (62%; P = 0.001) and adenocarcinomas (75%; P = 0.0001). RT-PCR performed in endoscopically normal rectal biopsies (n = 78) revealed a profound decrease in SA1 expression in adenoma-harboring patients (field carcinogenesis) compared with those who were neoplasia-free (47%; P = 0.03). From a racial perspective, colorectal cancer tissues from Caucasians had 56% higher SA1 expression than in African-Americans. This was mirrored in field carcinogenesis where healthy Caucasians expressed more SA1 at baseline compared with matched African-American subjects (73%; P = 0.003). However, as a biomarker for colorectal cancer risk, the diagnostic performance as assessed by area under ROC curve was greater in African-Americans (AUROC = 0.724) than in Caucasians (AUROC = 0.585). From a biologic perspective, SA1 modulation of high-order chromatin was demonstrated with both biophotonic (nanocytology) and chromatin accessibility [micrococcal nuclease (MNase)] assays in SA1-knockdown HT29 colorectal cancer cells. The functional consequences were underscored by increased proliferation (WST-1; P = 0.0002, colony formation; P = 0.001) in the SA1-knockdown HT29 cells. These results provide the first evidence indicating a tumor suppressor role of SA1 in early colon carcinogenesis and as a risk stratification biomarker giving potential insights into biologic basis of racial disparities in colorectal cancer. Cancer Prev Res; 9(11); 844-54. ©2016 AACR.
Collapse
Affiliation(s)
- Ramesh K Wali
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Navneet Momi
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Mart Dela Cruz
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Audrey H Calderwood
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | | | - Luay Almassalha
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Anuj Chhaparia
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | | | - Andrew Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Ashish K Tiwari
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Bilal Latif
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois
| | - Hemant K Roy
- Department of Medicine, Boston University Medical Center, Boston, Massachusetts.
| |
Collapse
|
3
|
Wali RK, Lee AH, Kam JC, Jonsson J, Thatcher A, Poretz D, Ambardar S, Piper J, Lynch C, Kulkarni S, Cochran J, Djurkovic S. Acute Neurological Illness in a Kidney Transplant Recipient Following Infection With Enterovirus-D68: An Emerging Infection? Am J Transplant 2015; 15:3224-8. [PMID: 26228743 DOI: 10.1111/ajt.13398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Revised: 04/28/2015] [Accepted: 05/13/2015] [Indexed: 01/25/2023]
Abstract
We report the first case of enterovirus-D68 infection in an adult living-donor kidney transplant recipient who developed rapidly progressive bulbar weakness and acute flaccid limb paralysis following an upper respiratory infection. We present a 45-year-old gentleman who underwent pre-emptive living-donor kidney transplantation for IgA nephropathy. Eight weeks following transplantation, he developed an acute respiratory illness from enterovirus/rhinovirus that was detectable in nasopharyngeal (NP) swabs. Within 24 h of onset of respiratory symptoms, the patient developed binocular diplopia which rapidly progressed to multiple cranial nerve dysfunctions (acute bulbar syndrome) over the next 24 h. Within the next 48 h, asymmetric flaccid paralysis of the left arm and urinary retention developed. While his neurological symptoms were evolving, the Centers for Disease Control reported that the enterovirus strain from the NP swabs was, in fact, Enterovirus-D68 (EV-D68). Magnetic resonance imaging of the brain demonstrated unique gray matter and anterior horn cell changes in the midbrain and spinal cord, respectively. Constellation of these neurological symptoms and signs was suggestive for postinfectious encephalomyelitis (acute disseminated encephalomyelitis [ADEM]) from EV-D68. Treatment based on the principles of ADEM included intensive physical therapy and other supportive measures, which resulted in a steady albeit slow improvement in his left arm and bulbar weakness, while maintaining stable allograft function.
Collapse
Affiliation(s)
- R K Wali
- Department of Surgery and Medicine, Inova Transplant Center, Falls Church, VA
| | - A H Lee
- Department of Radiology, Inova Health System, Falls Church, VA
| | - J C Kam
- Department of Nephrology, George Washington School of Medicine, Washington, DC
| | - J Jonsson
- Department of Surgery, Inova Transplant Center, Falls Church, VA
| | - A Thatcher
- Department of Surgery, Inova Transplant Center, Falls Church, VA
| | - D Poretz
- Department of Infectious Disease, Inova Health System, Falls Church, VA
| | - S Ambardar
- Department of Infectious Disease, Inova Health System, Falls Church, VA
| | - J Piper
- Department of Surgery, Inova Transplant Center, Falls Church, VA
| | - C Lynch
- Department of Medicine, Virginia Commonwealth University, Richmond, VA
| | - S Kulkarni
- Department of Neurology, Inova Health System, Falls Church, VA
| | - J Cochran
- Department of Neurology, Inova Health System, Falls Church, VA
| | - S Djurkovic
- Department of Pulmonary and Critical Care, Inova Health System, Falls Church, VA
| |
Collapse
|
4
|
Cruz MD, Wali RK, Bianchi LK, Radosevich AJ, Crawford SE, Jepeal L, Goldberg MJ, Weinstein J, Momi N, Roy P, Calderwood AH, Backman V, Roy HK. Colonic mucosal fatty acid synthase as an early biomarker for colorectal neoplasia: modulation by obesity and gender. Cancer Epidemiol Biomarkers Prev 2014; 23:2413-21. [PMID: 25155760 DOI: 10.1158/1055-9965.epi-14-0026] [Citation(s) in RCA: 8] [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] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND We have previously reported that colonic pericryptal microvascular blood flow is augmented in the premalignant colonic epithelium, highlighting the increased metabolic demand of the proliferative epithelium as a marker of field carcinogenesis. However, its molecular basis is unexplored. In this study, we assessed the expression of a regulator of the "lipogenic switch," fatty acid synthase (FASN), in early colon carcinogenesis for its potential biomarker utility for concurrent neoplasia. METHODS FASN expression (IHC) in the colonic epithelium from azoxymethane and polyposis in rat colon (Pirc) models of colorectal cancer was studied. FASN mRNA expression from endoscopically normal rectal mucosa was evaluated and correlated with colonoscopic findings (pathologic confirmation of neoplasia). RESULTS FASN expression progressively increased from premalignant to malignant stage in the azoxymethane model (1.9- to 2.5-fold; P < 0.0001) and was also higher in the adenomas compared with adjacent uninvolved mucosa (1.8- to 3.4-fold; P < 0.001) in the Pirc model. Furthermore, FASN was significantly overexpressed in rectal biopsies from patients harboring adenomas compared with those with no adenomas. These effects were accentuated in male (∼2-fold) and obese patients (1.4-fold compared with those with body mass index < 30). Overall, the performance of rectal FASN was excellent (AUROC of 0.81). CONCLUSIONS FASN is altered in the premalignant colonic mucosa and may serve as a marker for colonic neoplasia present elsewhere. The enhanced effects in men and obesity may have implications for identifying patient subgroups at risk for early-onset neoplasia. IMPACT These findings support the role of rectal FASN expression as a reliable biomarker of colonic neoplasia.
Collapse
Affiliation(s)
- Mart Dela Cruz
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Ramesh K Wali
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts.
| | - Laura K Bianchi
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois
| | - Andrew J Radosevich
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Susan E Crawford
- Department of Pathology, St. Louis University, St. Louis, Missouri
| | - Lisa Jepeal
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Michael J Goldberg
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois
| | - Jaclyn Weinstein
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Navneet Momi
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Priya Roy
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Audrey H Calderwood
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| | - Vadim Backman
- Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Hemant K Roy
- Section of Gastroenterology, Boston University Medical Center, Boston, Massachusetts
| |
Collapse
|
5
|
Wali RK, Hensing TA, Ray DW, Dela Cruz M, Tiwari AK, Radosevich A, Jepeal L, Fernando HC, Litle VR, Charlot M, Momi N, Backman V, Roy HK. Buccal microRNA dysregulation in lung field carcinogenesis: gender-specific implications. Int J Oncol 2014; 45:1209-15. [PMID: 24919547 PMCID: PMC4144027 DOI: 10.3892/ijo.2014.2495] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/13/2014] [Indexed: 12/18/2022] Open
Abstract
MicroRNAs (miRNAs) have been shown to be reliable early biomarkers in a variety of cancers including that of lung. We ascertained whether the biomarker potential of miRNAs could be validated in microscopically normal and easily accessible buccal epithelial brushings from cigarette smokers as a consequence of lung cancer linked ‘field carcinogenesis’. We found that compared to neoplasia-free subjects, a panel of 68 miRNAs were upregulated and 3 downregulated in the normal appearing buccal mucosal cells collected from patients harboring lung cancer (n=76). The performance characteristics of selected miRNAs (with ≥1-fold change) were excellent with an average under the receiver operator characteristic curve (AUROC) of >0.80. Several miRNAs also displayed gender specificity between the groups. These results provide the first proof-of-concept scenario in which minimally intrusive cheek brushings could provide an initial screening tool in a large at-risk population.
Collapse
Affiliation(s)
- Ramesh K Wali
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Thomas A Hensing
- Department of Surgery, NorthShore University Health Systems, Evanston, IL 60201, USA
| | - Daniel W Ray
- Department of Medicine, NorthShore University Health Systems, Evanston, IL 60201, USA
| | - Mart Dela Cruz
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Ashish K Tiwari
- Department of Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Andrew Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60201, USA
| | - Lisa Jepeal
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Hiran C Fernando
- Department of Surgery, Boston University Medical Center, Boston, MA 02118, USA
| | - Virginia R Litle
- Department of Surgery, Boston University Medical Center, Boston, MA 02118, USA
| | - Marjory Charlot
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Navneet Momi
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, IL 60201, USA
| | - Hemant K Roy
- Department of Medicine, Boston University Medical Center, Boston, MA 02118, USA
| |
Collapse
|
6
|
Cherkezyan L, Stypula-Cyrus Y, Subramanian H, White C, Dela Cruz M, Wali RK, Goldberg MJ, Bianchi LK, Roy HK, Backman V. Nanoscale changes in chromatin organization represent the initial steps of tumorigenesis: a transmission electron microscopy study. BMC Cancer 2014; 14:189. [PMID: 24629088 PMCID: PMC3995586 DOI: 10.1186/1471-2407-14-189] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 03/05/2014] [Indexed: 12/16/2022] Open
Abstract
Background Nuclear alterations are a well-known manifestation of cancer. However, little is known about the early, microscopically-undetectable stages of malignant transformation. Based on the phenomenon of field cancerization, the tissue in the field of a tumor can be used to identify and study the initiating events of carcinogenesis. Morphological changes in nuclear organization have been implicated in the field of colorectal cancer (CRC), and we hypothesize that characterization of chromatin alterations in the early stages of CRC will provide insight into cancer progression, as well as serve as a biomarker for early detection, risk stratification and prevention. Methods For this study we used transmission electron microscopy (TEM) images of nuclei harboring pre-neoplastic CRC alterations in two models: a carcinogen-treated animal model of early CRC, and microscopically normal-appearing tissue in the field of human CRC. We quantify the chromatin arrangement using approaches with two levels of complexity: 1) binary, where chromatin is separated into areas of dense heterochromatin and loose euchromatin, and 2) grey-scale, where the statistics of continuous mass-density distribution within the nucleus is quantified by its spatial correlation function. Results We established an increase in heterochromatin content and clump size, as well as a loss of its characteristic peripheral positioning in microscopically normal pre-neoplastic cell nuclei. Additionally, the analysis of chromatin density showed that its spatial distribution is altered from a fractal to a stretched exponential. Conclusions We characterize quantitatively and qualitatively the nanoscale structural alterations preceding cancer development, which may allow for the establishment of promising new biomarkers for cancer risk stratification and diagnosis. The findings of this study confirm that ultrastructural changes of chromatin in field carcinogenesis represent early neoplastic events leading to the development of well-documented, microscopically detectable hallmarks of cancer.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
| |
Collapse
|
7
|
Roy HK, Damania DP, DelaCruz M, Kunte DP, Subramanian H, Crawford SE, Tiwari AK, Wali RK, Backman V. Nano-architectural alterations in mucus layer fecal colonocytes in field carcinogenesis: potential for screening. Cancer Prev Res (Phila) 2013; 6:1111-9. [PMID: 23983085 DOI: 10.1158/1940-6207.capr-13-0138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Current fecal tests (occult blood, methylation, DNA mutations) target minute amounts of tumor products among a large amount of fecal material and thus have suboptimal performance. Our group has focused on exploiting field carcinogenesis as a modality to amplify the neoplastic signal. Specifically, we have shown that endoscopically normal rectal brushings have striking nano-architectural alterations which are detectable using a novel optical technique, partial wave spectroscopic microscopy (PWS). We therefore wished to translate this approach to a fecal assay. We examined mucus layer fecal colonocytes (MLFC) at preneoplastic and neoplastic time points (confirmed with rat colonoscopy) in the azoxymethane (AOM)-treated rat model and conducted PWS analysis to derive the nano-architectural parameter, disorder strength (Ld). We confirmed these results with studies in a genetic model (the Pirc rat). We showed that MLFC appeared microscopically normal, consistent with field carcinogenesis. Ld was elevated at an early time point (5 weeks post-AOM injection, effect size = 0.40, P = 0.024) and plateaued before adenoma formation (10 weeks post-AOM, effect size = 0.66, P = 0.001), with no dramatic increase once tumors developed. We replicated these data in the preneoplastic Pirc rat with an effect size in the MLFC that replicated the rectal brushings (increase vs. age-matched controls of 62% vs. 74%, respectively). We provide the first demonstration of a biophotonics approach to fecal assay. Furthermore, targeting the nano-architectural changes of field carcinogenesis rather than the detection of tumor products may provide a novel paradigm for colorectal cancer screening.
Collapse
Affiliation(s)
- Hemant K Roy
- Boston University School of Medicine, Boston Medical Center, 650 Albany Street, Suite 526, Boston, MA 02118.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Kunte DP, DelaCruz M, Wali RK, Menon A, Du H, Stypula Y, Patel A, Backman V, Roy HK. Dysregulation of microRNAs in colonic field carcinogenesis: implications for screening. PLoS One 2012; 7:e45591. [PMID: 23049818 PMCID: PMC3458063 DOI: 10.1371/journal.pone.0045591] [Citation(s) in RCA: 25] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 08/23/2012] [Indexed: 12/18/2022] Open
Abstract
Colorectal cancer (CRC) screening tests often have a trade-off between efficacy and patient acceptability/cost. Fecal tests (occult blood, methylation) engender excellent patient compliance but lack requisite performance underscoring the need for better population screening tests. We assessed the utility of microRNAs (miRNAs) as markers of field carcinogenesis and their potential role for CRC screening using the azoxymethane (AOM)-treated rat model. We found that 63 miRNAs were upregulated and miR-122, miR-296-5p and miR-503# were downregulated in the uninvolved colonic mucosa of AOM rats. We monitored the expression of selected miRNAs in colonic biopsies of AOM rats at 16 weeks and correlated it with tumor development. We noted that the tumor bearing rats had significantly greater miRNA modulation compared to those without tumors. The miRNAs showed good diagnostic performance with an area under the receiver operator curve (AUROC) of >0.7. We also noted that the miRNA induction in the colonic mucosa was mirrorred in the mucus layer fecal colonocytes isolated from AOM rat stool and the degree of miRNA induction was greater in the tumor bearing rats compared to those without tumors. Lastly, we also noted significant miRNA modulation in the Pirc rats- the genetic model of colon carcinogenesis, both in the uninvolved colonic mucosa and the fecal colonocytes. We thus demonstrate that miRNAs are excellent markers of field carcinogenesis and could accurately predict future neoplasia. Based on our results, we propose an accurate, inexpensive, non-invasive miRNA test for CRC risk stratification based on rectal brushings or from abraded fecal colonocytes.
Collapse
Affiliation(s)
- Dhananjay P. Kunte
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Mart DelaCruz
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Ramesh K. Wali
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Ashwaty Menon
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Hongyan Du
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Yolanda Stypula
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Amir Patel
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois, United States of America
| | - Hemant K. Roy
- Department of Medicine, NorthShore University HealthSystem, Evanston, Illinois, United States of America
- * E-mail:
| |
Collapse
|
9
|
Tiwari AK, Laird-Fick HS, Wali RK, Roy HK. Surveillance for gastrointestinal malignancies. World J Gastroenterol 2012; 18:4507-16. [PMID: 22969223 PMCID: PMC3435775 DOI: 10.3748/wjg.v18.i33.4507] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2012] [Revised: 03/28/2012] [Accepted: 04/12/2012] [Indexed: 02/06/2023] Open
Abstract
Gastrointestinal (GI) malignancies are notorious for frequently progressing to advanced stages even in the absence of serious symptoms, thus leading to delayed diagnoses and dismal prognoses. Secondary prevention of GI malignancies through early detection and treatment of cancer-precursor/premalignant lesions, therefore, is recognized as an effective cancer prevention strategy. In order to efficiently detect these lesions, systemic application of screening tests (surveillance) is needed. However, most of the currently used non-invasive screening tests for GI malignancies (for example, serum markers such as alpha-fetoprotein for hepatocellular carcinoma, and fecal occult blood test, for colon cancer) are only modestly effective necessitating the use of highly invasive endoscopy-based procedures, such as esophagogastroduodenoscopy and colonoscopy for screening purposes. Even for hepatocellular carcinoma where non-invasive imaging (ultrasonography) has become a standard screening tool, the need for repeated liver biopsies of suspicious liver nodules for histopathological confirmation can’t be avoided. The invasive nature and high-cost associated with these screening tools hinders implementation of GI cancer screening programs. Moreover, only a small fraction of general population is truly predisposed to developing GI malignancies, and indeed needs surveillance. To spare the average-risk individuals from superfluous invasive procedures and achieve an economically viable model of cancer prevention, it’s important to identify cohorts in general population that are at substantially high risk of developing GI malignancies (risk-stratification), and select suitable screening tests for surveillance in these cohorts. We herein provide a brief overview of such high-risk cohorts for different GI malignancies, and the screening strategies that have commonly been employed for surveillance purpose in them.
Collapse
|
10
|
Gomes AJ, Ruderman S, DelaCruz M, Wali RK, Roy HK, Backman V. In vivo measurement of the shape of the tissue-refractive-index correlation function and its application to detection of colorectal field carcinogenesis. J Biomed Opt 2012; 17:047005. [PMID: 22559696 PMCID: PMC3382344 DOI: 10.1117/1.jbo.17.4.047005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Polarization-gated spectroscopy is an established method to depth-selectively interrogate the structural properties of biological tissue. We employ this method in vivo in the azoxymethane (AOM)-treated rat model to monitor the morphological changes that occur in the field of a tumor during early carcinogenesis. The results demonstrate a statistically significant change in the shape of the refractive-index correlation function for AOM-treated rats versus saline-treated controls. Since refractive index is linearly proportional to mass density, these refractive-index changes can be directly linked to alterations in the spatial distribution patterns of macromolecular density. Furthermore, we found that alterations in the shape of the refractive-index correlation function shape were an indicator of both present and future risk of tumor development. These results suggest that noninvasive measurement of the shape of the refractive-index correlation function could be a promising marker of early cancer development.
Collapse
Affiliation(s)
- Andrew J. Gomes
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60218
| | - Sarah Ruderman
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60218
| | - Mart DelaCruz
- NorthShore University Health System, Department of Internal Medicine, Evanston, Illinois 60218
| | - Ramesh K. Wali
- NorthShore University Health System, Department of Internal Medicine, Evanston, Illinois 60218
| | - Hemant K. Roy
- NorthShore University Health System, Department of Internal Medicine, Evanston, Illinois 60218
| | - Vadim Backman
- Northwestern University, Department of Biomedical Engineering, Evanston, Illinois 60218
- Address all correspondence to: Vadim Backman, Northwestern University, Department of Biomedical Engineering, 2145 Sheridan Road, BME-E310, Evanston, Illinois 60218. Tel: +847 4913536; Fax: +847 4914928; E-mail:
| |
Collapse
|
11
|
Gandhi SR, Tiwari AK, Kunte DP, De la Cruz MA, Stypula Y, Gibson T, Brasky J, Backman V, Wali RK, Roy HK. Association of stem-like cells in gender-specific chemoprevention against intestinal neoplasia in MIN mouse. Oncol Rep 2011; 26:1127-32. [PMID: 21769438 DOI: 10.3892/or.2011.1395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2011] [Accepted: 05/06/2011] [Indexed: 11/05/2022] Open
Abstract
This study was undertaken to examine the gender-sensitivity and chemopreventive responsiveness of celecoxib on intestinal stem-like cells as a biomarker of colon carcino-genesis, using the MIN mouse model. Male and female MIN mice (6-7-weeks old) were randomized to either control diet or to a diet supplemented with celecoxib (1,500 ppm). The animals were euthanized ten weeks later and the intestines were flushed and opened longitudinally to assess tumor count. Small intestinal segments were formalin-fixed and tissue sections were subjected to immunohistochemical evaluation of DCAMKL1, a known marker of stem-like cells. We found that in animals receiving control (AIN 76A diet) alone, female MIN mice had a higher polyp count than males (52.32 ± 13.89 vs. 35.43 ± 16.05; p<0.0005). However, compared to control diet groups, celecoxib supplementation caused a larger reduction in the number of polyps in females than their male cohorts (6.38 ± 1.43 vs. 12.83 ± 6.74; a reduction of 88% in females to 64% in males). Significant differences (p=0.013) were observed in the number of DCAMKL1-stained cells in the crypts of the wild-type (WT) (10.01 ± 1.07 stem cells per high powered field; HPF) compared to the MIN mice (24.15 ± 8.08 stem cells per HPF), illustrating increased stem-like cells in animals that are more prone to neoplasia. DCAMKL1 labeled stem-like cells were equal in number in the male and female groups receiving the control AIN 76A diet alone (females, 25.73 stem-like cells/HPF); males, 24.15 stem-like cells/HPF). However, females showed a greater reduction in the number of DCAMKL1-labeled stem-like cells with celecoxib supplementation than the respective males (16.63 ± 4.23 vs. 21.56 ± 9.06; a reduction of 35.4% in females to 10.7% in males). We conclude that a higher number of stem-like cells in the uninvolved mucosa paralleled tumorigenesis and mirrored greater chemopreventive responsiveness of female MIN mice compared to males.
Collapse
Affiliation(s)
- Seema R Gandhi
- Department of Internal Medicine, NorthShore University Healthsystem, Evanston, IL 60201, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Tiwari AK, Crawford SE, Radosevich A, Wali RK, Stypula Y, Kunte DP, Mutyal N, Ruderman S, Gomes A, Cornwell ML, De La Cruz M, Brasky J, Gibson TP, Backman V, Roy HK. Neo-angiogenesis and the premalignant micro-circulatory augmentation of early colon carcinogenesis. Cancer Lett 2011; 306:205-13. [PMID: 21493000 DOI: 10.1016/j.canlet.2011.03.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 03/07/2011] [Accepted: 03/11/2011] [Indexed: 12/23/2022]
Abstract
Spectroscopic techniques have demonstrated that in the microscopically normal mucosa, there is an increase in mucosal micro-circulation in patients harboring neoplasia elsewhere in the colon (i.e. marker of field carcinogenesis). However, the physiological and molecular basis of this early increase in blood supply (EIBS) has not been elucidated. We, therefore, investigated the microvessel density (MVD) and angiogenic gene expression in the premalignant colonic mucosa from the well-validated azoxymethane (AOM)-treated rat experimental model of colon carcinogenesis. Fisher 344 rats were treated with AOM (15 mg/kg i.p.) or saline and euthanized 14 weeks later (a time-point that precedes carcinoma development). Colon sections were studied for MVD via immunohistochemical assessment for CD31 and location was compared with optical assessment of mucosal hemoglobin with low-coherence enhanced backscattering spectroscopy (LEBS). Finally, we performed a pilot real-time PCR angiogenesis microarray (84 genes) from the microscopically normal colonic mucosa of AOM and age-matched saline treated rats. AOM treatment increased MVD in both the mucosa and submucosa of the rats (125% increase in mucosa; p<0.007, and 96% increase in submucosa; p<0.02) but the increase was most pronounced at the cryptal base consistent with the LEBS data showing maximal hemoglobin augmentation at 200-225 μm depth. Microarray analysis showed striking dysregulation of angiogenic and anti-angiogenic factors. We demonstrate, for the first time, that neo-angiogenesis occurs in the microscopically normal colonic mucosa and was accentuated at the bottom of the crypt. This finding has potential implications as a biomarker for risk-stratification and target for chemoprevention.
Collapse
Affiliation(s)
- Ashish K Tiwari
- Department of Medicine, NorthShore University HealthSystem, Evanston, IL, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
13
|
Qi W, Joshi S, Weber CR, Wali RK, Roy HK, Savkovic SD. Polyethylene glycol diminishes pathological effects of Citrobacter rodentium infection by blocking bacterial attachment to the colonic epithelia. Gut Microbes 2011; 2:267-73. [PMID: 22067938 PMCID: PMC3242793 DOI: 10.4161/gmic.2.5.18256] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 02/03/2023] Open
Abstract
Infections from enteric bacteria such as enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic Escherichia coli (EHEC) are a public health threat worldwide. EPEC and EHEC are extracellular pathogens, and their interaction with host surface receptors is critical to the infection process. We previously demonstrated that polyethylene glycol (PEG) downregulates surface receptors in intestinal cells. Here we show that PEG decreases β1-integrin, the surface receptor in intestinal cells that is critical for EPEC and EHEC attachment. We hypothesized that PEG would inhibit the attachment of these enteric pathogens to host cells and improve clinical signs of infection. We found that attachment of the mouse enteric pathogen Citrobacter rodentium, which belongs to the same group of pathogens as EPEC and EHEC, was attenuated by the concurrent presence of PEG. Pretreatment with PEG, without concurrent presence during infection, also reduced bacterial attachment. This finding was further supported in vivo such as that PEG administered by gavage daily during infection as well as prior to infection significantly decreased C. rodentium in the colon and improved the appearance of the infected colon in mice. In addition, PEG decreased the β1-integrin in colonic mucosa and reduced the C. rodentium-induced activation of epidermal growth factor receptors. PEG also significantly reduced infection-induced colonic inflammation. Finally, PEG efficiently reduced C. rodentium shedding from the colon during infection. In conclusion, PEG can be an efficient and safe preventive agent against EPEC and EHEC infections.
Collapse
Affiliation(s)
- Wentao Qi
- Department of Medicine; Division of Gastroenterology; NorthShore University Research Institute; Evanston; IL USA
| | - Suhasini Joshi
- Department of Medicine; Division of Gastroenterology; NorthShore University Research Institute; Evanston; IL USA
| | | | - Ramesh K Wali
- Department of Medicine; Division of Gastroenterology; NorthShore University Research Institute; Evanston; IL USA
| | - Hemant K Roy
- Department of Medicine; Division of Gastroenterology; NorthShore University Research Institute; Evanston; IL USA
| | - Suzana D Savkovic
- Department of Medicine; Division of Gastroenterology; NorthShore University Research Institute; Evanston; IL USA
| |
Collapse
|
14
|
Radosevich AJ, Turzhitsky VM, Mutyal NN, Rogers JD, Stoyneva V, Tiwari AK, De La Cruz M, Kunte DP, Wali RK, Roy HK, Backman V. Depth-resolved measurement of mucosal microvascular blood content using
low-coherence enhanced backscattering spectroscopy. Biomed Opt Express 2010; 1:1196-1208. [PMID: 21258541 PMCID: PMC3018078 DOI: 10.1364/boe.1.001196] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/07/2010] [Revised: 10/10/2010] [Accepted: 10/17/2010] [Indexed: 05/04/2023]
Abstract
Low-coherence enhanced backscattering (LEBS) spectroscopy is a light scattering technique which uses partial spatial coherence broadband illumination to interrogate the optical properties at sub-diffusion length scales. In this work, we present a post-processing technique which isolates the hemoglobin concentration at different depths within a sample using a single spectroscopic LEBS measurement with a fixed spatial coherence of illumination. We verify the method with scattering (spectralon reflectance standard and polystyrene microspheres) and absorbing (hemoglobin) phantoms. We then demonstrate the relevance of this method for quantifying hemoglobin content as a function of depth within biological tissue using the azoxymethane treated animal model of colorectal cancer.
Collapse
Affiliation(s)
- Andrew J. Radosevich
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Vladimir M. Turzhitsky
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Nikhil N. Mutyal
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Jeremy D. Rogers
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Valentina Stoyneva
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| | - Ashish Kumar Tiwari
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Mart De La Cruz
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Dhananjay P. Kunte
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Ramesh K. Wali
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Hemant K. Roy
- Department of Gastroenterology, Northshore University Healthsystems, Evanston, Illinois 60201, USA
| | - Vadim Backman
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA
| |
Collapse
|
15
|
Wali RK, Kunte DP, Koetsier JL, Bissonnette M, Roy HK. Polyethylene glycol-mediated colorectal cancer chemoprevention: roles of epidermal growth factor receptor and Snail. Mol Cancer Ther 2008; 7:3103-11. [PMID: 18790788 DOI: 10.1158/1535-7163.mct-08-0434] [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] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Polyethylene glycol (PEG) is a clinically widely used agent with profound chemopreventive properties in experimental colon carcinogenesis. We reported previously that Snail/beta-catenin signaling may mediate the suppression of epithelial proliferation by PEG, although the upstream events remain unclear. We report herein the role of epidermal growth factor receptor (EGFR), a known mediator of Snail and overexpressed in approximately 80% of human colorectal cancers, on PEG-mediated antiproliferative and hence antineoplastic effects in azoxymethane (AOM) rats and HT-29 colon cancer cells. AOM rats were randomized to either standard diet or one with 10% PEG-3350 and euthanized 8 weeks later. The colonic samples were subjected to immunohistochemical or Western blot analyses. PEG decreased mucosal EGFR by 60% (P < 0.001). Similar PEG effects were obtained in HT-29 cells. PEG suppressed EGFR protein via lysosmal degradation with no change in mRNA levels. To show that EGFR antagonism per se was responsible for the antiproliferative effect, we inhibited EGFR by either pretreating cells with gefitinib or stably transfecting with EGFR-short hairpin RNA and measured the effect of PEG on proliferation. In either case, PEG effect was blunted, suggesting a vital role of EGFR. Flow cytometric analysis revealed that EGFR-short hairpin RNA cells, besides having reduced membrane EGFR, also expressed low Snail levels (40%), corroborating a strong association. Furthermore, in EGFR silenced cells, PEG effect on EGFR or Snail was muted, similar to that on proliferation. In conclusion, we show that EGFR is the proximate membrane signaling molecule through which PEG initiates antiproliferative activity with Snail/beta-catenin pathway playing the central intermediary function.
Collapse
Affiliation(s)
- Ramesh K Wali
- Feinberg School of Medicine at Northwestern University, Department of Internal Medicine, Evanston Northwestern Healthcare, 1001 University Place, Suite 314, Evanston, IL 60201, USA.
| | | | | | | | | |
Collapse
|
16
|
Kunte DP, Wali RK, Koetsier JL, Roy HK. Antiproliferative effect of sulindac in colonic neoplasia prevention: role of COOH-terminal Src kinase. Mol Cancer Ther 2008; 7:1797-806. [PMID: 18644992 DOI: 10.1158/1535-7163.mct-08-0022] [Citation(s) in RCA: 11] [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: 12/31/2022]
Abstract
Although the nonsteroidal anti-inflammatory drugs (NSAID) protection against colorectal cancer is well established, the molecular mechanisms remain unclear. We show herein that induction of the tumor suppressor gene COOH-terminal Src kinase (Csk) by NSAID is important for their antiproliferative and hence chemopreventive effects. In the azoxymethane-treated rat model of experimental colon carcinogenesis, sulindac treatment markedly induced Csk with a corresponding increase in inhibitory phosphorylation of Src (Tyr(527)). Sulindac-mediated Csk induction was replicated in the human colorectal cancer cell line HT-29, with a corresponding suppression of both Src kinase activity (63% of vehicle; P < 0.05) and E-cadherin tyrosine phosphorylation (an in vivo Src target). To determine the importance of Csk in NSAID antiproliferative activity, we stably transfected a Csk-specific short hairpin RNA (shRNA) vector into HT-29 cells, thereby blunting the sulindac-mediated Csk induction. These transfectants were significantly less responsive to the antiproliferative effect of sulindac sulfide (suppression of proliferating cell nuclear antigen was 21 +/- 2.3% in transfectants versus 45 +/- 4.23% in wild-type cells), with a corresponding mitigation of the sulindac-mediated G(1)-S-phase arrest (S-phase cells 48 +/- 3.6% versus 14 +/- 2.8% of vehicle respectively). Importantly, the Csk shRNA cells had a marked decrease in the cyclin-dependent kinase inhibitor p21(cip/waf1), a critical regulator of G(1)-S-phase progression (49% of wild-type cells). Moreover, although sulindac-mediated induction of p21(cip/waf1) was 113% in wild-type HT-29, this induction was alleviated in the Csk shRNA transfectants (65% induction; P < 0.01). Thus, this is the first demonstration that the antiproliferative activity of NSAID is modulated, at least partly, through the Csk/Src axis.
Collapse
Affiliation(s)
- Dhananjay P Kunte
- Feinberg School of Medicine at Northwestern University, Department of Internal Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Suite G208, Evanston, IL 60201, USA
| | | | | | | |
Collapse
|
17
|
Roy HK, Wali RK, Kim Y, Liu Y, Hart J, Kunte DP, Koetsier JL, Goldberg MJ, Backman V. Inducible nitric oxide synthase (iNOS) mediates the early increase of blood supply (EIBS) in colon carcinogenesis. FEBS Lett 2007; 581:3857-62. [PMID: 17658518 PMCID: PMC2913280 DOI: 10.1016/j.febslet.2007.07.012] [Citation(s) in RCA: 21] [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] [Received: 05/09/2007] [Revised: 06/27/2007] [Accepted: 07/03/2007] [Indexed: 11/25/2022]
Abstract
We have recently demonstrated that dramatic alteration in mucosal microvascular blood content termed early increase in blood supply (EIBS) is a hallmark of early colon carcinogenesis. In the current study, we elucidate the mechanism of EIBS by assessing iNOS/nitric oxide axis in the histologically normal colonic mucosa of rats treated with the colon-specific carcinogen, azoxymethane. We demonstrate that there was a strong temporal correlation between EIBS and iNOS expression/activity. Importantly, we also observed that short-term treatment with nitric oxide inhibitor abrogated EIBS. These data indicate that iNOS induction may have a critical role in augmenting the predysplastic mucosal blood supply and thereby fostering colon carcinogenesis.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Medicine, Feinberg School of Medicine at Northwestern University, Section of Gastroenterology, Evanston-Northwestern Healthcare, G208 Evanston Hospital, 2650 Ridge Avenue, Evanston, IL 60201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Wali RK, Mohanlal V, Ramos E, Blahut S, Drachenberg C, Papadimitriou J, Dinits M, Joshi A, Philosophe B, Foster C, Cangro C, Nogueira J, Cooper M, Bartlett ST, Weir MR. Early withdrawal of calcineurin inhibitors and rescue immunosuppression with sirolimus-based therapy in renal transplant recipients with moderate to severe renal dysfunction. Am J Transplant 2007; 7:1572-83. [PMID: 17511682 DOI: 10.1111/j.1600-6143.2007.01825.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Mammalian Target-of-Rapamycin inhibitors (mTOR inhibitors) can be used to replace the calcineurin inhibitors (CNIs) to prevent progression in chronic kidney disease (CKD) following organ transplantation. Discontinuation of tacrolimus in 136 recipients of kidney transplants with progressive renal dysfunction significantly decreased the rate of loss of estimated glomerular filtration rate (eGFR, mL/min/1.73 m(2)) (pre-intervention vs. post-intervention slopes, -0.013 vs. -0.002, p < 0.0001). Discontinuation of tacrolimus was associated with a sustained and significant improvement in graft function (pre-eGFR vs. post-eGFR; 26.0 +/- 1.1 vs. 47.4 +/- 2.1, p < 0.0001) in 74% of patients. This intervention was ineffective if the mean and (median) values of creatinine (mg/dL) and eGFR were 3.8 +/- 0.2 (3.4) and 18.4 +/- 1.9 (22.4), respectively, at the time of conversion therapy. During the follow-up (range, 1.5-34.6, months), a total of 13 patients had their first acute rejection following the conversion therapy, an annual incidence of less than 10% and none of these episodes resulted in graft loss. The salutary effects of sirolimus therapy following discontinuation of tacrolimus in patients with moderate to severe graft dysfunction due to allograft nephropathy even in high-risk patients improves kidney function and prevents acute rejection.
Collapse
Affiliation(s)
- R K Wali
- Division of Nephrology, Department of Medicine, Unniversity of Maryland School of Medicine, Baltimore, MD, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Roy HK, Kunte DP, Koetsier JL, Hart J, Kim YL, Liu Y, Bissonnette M, Goldberg M, Backman V, Wali RK. Chemoprevention of colon carcinogenesis by polyethylene glycol: suppression of epithelial proliferation via modulation of SNAIL/beta-catenin signaling. Mol Cancer Ther 2006; 5:2060-9. [PMID: 16928827 DOI: 10.1158/1535-7163.mct-06-0054] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [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
Polyethylene glycol (PEG) is one of the most potent chemopreventive agents against colorectal cancer; however, the mechanisms remain largely unexplored. In this study, we assessed the ability of PEG to target cyclin D1-beta-catenin-mediated hyperproliferation in the azoxymethane-treated rat model and the human colorectal cancer cell line, HT-29. Azoxymethane-treated rats were randomized to AIN-76A diet alone or supplemented with 5% PEG-8000. After 30 weeks, animals were euthanized and biopsies of aberrant crypt foci and uninvolved crypts were subjected to immunohistochemical and immunoblot analyses. PEG markedly suppressed both early and late markers of azoxymethane-induced colon carcinogenesis (fractal dimension by 80%, aberrant crypt foci by 64%, and tumors by 74%). In both azoxymethane-treated rats and HT-29 cells treated with 5% PEG-3350 for 24 hours, PEG decreased proliferation (45% and 52%, respectively) and cyclin D1 (78% and 56%, respectively). Because beta-catenin is the major regulator of cyclin D1 in colorectal cancer, we used the T-cell factor (Tcf)-TOPFLASH reporter assay to show that PEG markedly inhibited beta-catenin transcriptional activity. PEG did not alter total beta-catenin expression but rather its nuclear localization, leading us to assess E-cadherin expression (a major determinant of beta-catenin subcellular localization), which was increased by 73% and 71% in the azoxymethane-rat and HT-29 cells, respectively. We therefore investigated the effect of PEG treatment on levels of the negative regulator of E-cadherin, SNAIL, and observed a 50% and 75% decrease, respectively. In conclusion, we show, for the first time, a molecular mechanism through which PEG imparts its antiproliferative and hence profound chemopreventive effect.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Internal Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, IL, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Kim YL, Turzhitsky VM, Liu Y, Roy HK, Wali RK, Subramanian H, Pradhan P, Backman V. Low-coherence enhanced backscattering: review of principles and applications for colon cancer screening. J Biomed Opt 2006; 11:041125. [PMID: 16965153 DOI: 10.1117/1.2236292] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The phenomenon of enhanced backscattering (EBS) of light, also known as coherent backscattering (CBS) of light, has been the object of intensive investigation in nonbiological media over the last two decades. However, there have been only a few attempts to explore EBS for tissue characterization and diagnosis. We have recently made progress in the EBS measurements in tissue by taking advantage of low spatial coherence illumination, which has led us to the development of low-coherence enhanced backscattering (LEBS) spectroscopy. In this work, we review the current state of research on LEBS. After a brief discussion of the basic principle of EBS and LEBS, we present an overview of the unique features of LEBS for tissue characterization, and show that LEBS enables depth-selective spectroscopic assessment of mucosal tissue. Then, we demonstrate the potential of LEBS spectroscopy for predicting the risk of colon carcinogenesis and colonoscopy-free screening for colorectal cancer (CRC).
Collapse
Affiliation(s)
- Young L Kim
- Northwestern University, Biomedical Engineering Department, Evanston, Illinois 60208, USA.
| | | | | | | | | | | | | | | |
Collapse
|
21
|
Roy HK, Kim YL, Liu Y, Wali RK, Goldberg MJ, Turzhitsky V, Horwitz J, Backman V. Risk stratification of colon carcinogenesis through enhanced backscattering spectroscopy analysis of the uninvolved colonic mucosa. Clin Cancer Res 2006; 12:961-8. [PMID: 16467111 DOI: 10.1158/1078-0432.ccr-05-1605] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [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: 12/15/2022]
Abstract
INTRODUCTION Our group has been interested in applying advances in biomedical optics to colorectal cancer risk stratification. Through a recent technological breakthrough, we have been able to harness information from enhanced backscattering spectroscopy, an optics phenomenon that allows quantitative, depth-selective analysis of the epithelial microscale/nanoscale architecture. In the present study, we investigated the ability of enhanced backscattering analysis of the preneoplastic mucosa to predict risk of colon carcinogenesis. METHODS Enhanced backscattering analysis was done on intestinal mucosa at preneoplastic time points from two experimental models of colorectal cancer: the azoxymethane-treated rat and the multiple intestinal neoplasia (MIN) mouse. Data were analyzed using two previously validated spectral markers: spectral slope and principle components. We then did a pilot study on mucosal biopsies from 63 subjects undergoing screening colonoscopy. RESULTS In the azoxymethane-treated rat, when compared with saline-treated controls, significant changes in the enhanced backscattering markers were observed as early as 2 weeks after azoxymethane treatment (before the development of aberrant crypt foci and adenomas). Enhanced backscattering markers continued to progress over time in a manner consonant with future neoplasia. These data were replicated in the preneoplastic MIN mouse mucosa. In humans, spectral slopes in the endoscopically normal cecum, midtransverse colon, and rectum were markedly reduced in patients harboring adenomas when compared with those who were neoplasia free. CONCLUSIONS We show, for the first time, that enhanced backscattering analysis of an aliquot of uninvolved mucosa has the potential for predicting neoplastic risk throughout the colon in both experimental colorectal cancer models and humans.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Medicine, Evanston Northwestern Healthcare Research Institute, Feinberg School of Medicine at Northwestern University, Evanston, Illinois 60201, USA.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
Siegel MP, Kim YL, Roy HK, Wali RK, Backman V. Assessment of blood supply in superficial tissue by polarization-gated elastic light-scattering spectroscopy. Appl Opt 2006; 45:335-42. [PMID: 16422163 DOI: 10.1364/ao.45.000335] [Citation(s) in RCA: 10] [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] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
We report the feasibility of monitoring both hemoglobin oxygen saturation and hemoglobin concentration in the superficial layer of tissue using polarization-gated elastic light-scattering spectroscopy. We detail our analysis technique, the experimental validation of our analysis, and the detection of an early increase in blood supply to the superficial layer of colon tissue in human patients with colonic adenomas as well as in an animal model of colon carcinogenesis. To the best of our knowledge, this study represents the first evidence that polarization gating can be used as a spectroscopic tool to quantify hemoglobin concentration as well as oxygen saturation in the uppermost tissue layer.
Collapse
Affiliation(s)
- Michael P Siegel
- Department of Biomedical Engineering, E310, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
| | | | | | | | | |
Collapse
|
23
|
Roy HK, Kim YL, Wali RK, Liu Y, Koetsier J, Kunte DP, Goldberg MJ, Backman V. Spectral markers in preneoplastic intestinal mucosa: an accurate predictor of tumor risk in the MIN mouse. Cancer Epidemiol Biomarkers Prev 2005; 14:1639-45. [PMID: 16030095 DOI: 10.1158/1055-9965.epi-04-0837] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [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] Open
Abstract
BACKGROUND We have reported recently that microarchitectural analysis of the histologically normal mucosa using a novel optics technology, four-dimensional elastic light scattering fingerprinting (ELF), provided unprecedented sensitivity for early detection of colon carcinogenesis. In the present study, we explored the ability of four-dimensional ELF to identify an inherited predisposition to colorectal cancer, an issue of considerable importance for optimizing population screening strategies. METHODS We used the MIN mouse, a model whose germ line adenomatous polyposis coli truncation leads to spontaneous intestinal tumorigenesis, thus replicating the human syndrome, familial adenomatous polyposis. Spectral markers were assessed by four-dimensional ELF analysis in MIN mice at preneoplastic time points and compared with age-matched controls (C57BL6 mice with wild-type adenomatous polyposis coli). To assess the responsiveness of spectral markers to chemopreventive agents, a subset of MIN mice was supplemented with celecoxib 1,500 ppm. RESULTS Spectral slope, fractal dimension, and principal component 3 were dramatically altered in the uninvolved MIN mouse mucosa at the earliest time points. Furthermore, alteration in spectral variables increased over time, consonant with the microarchitectural underpinnings of subsequent tumorigenesis. Additionally, these markers spatially correlated with future adenoma development (small intestine > colon). Short-term treatment with the potent chemopreventive agent, celecoxib, resulted in near normalization of fractal dimension and principal component 3. CONCLUSIONS We report, for the first time, that spectral markers, assayed by four-dimensional ELF, were able to sensitively identify a genetic predisposition for intestinal tumorigenesis before the occurrence of phenotypic manifestations. Moreover, the reversal of spectral markers by celecoxib treatment supports the neoplastic relevance.
Collapse
Affiliation(s)
- Hemant K Roy
- Feinberg School of Medicine at Northwestern University, Department of Internal Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston, IL 60201, USA.
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Kunte DP, Wali RK, Koetsier JL, Hart J, Kostjukova MN, Kilimnik AY, Pyatkin IG, Strelnikova SR, Roy HK. Down-regulation of the tumor suppressor gene C-terminal Src kinase: An early event during premalignant colonic epithelial hyperproliferation. FEBS Lett 2005; 579:3497-502. [PMID: 15961079 DOI: 10.1016/j.febslet.2005.05.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [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: 03/11/2005] [Revised: 05/03/2005] [Accepted: 05/06/2005] [Indexed: 11/23/2022]
Abstract
Hyperproliferation of the premalignant epithelium is critical for colonic carcinogenesis; however the mechanisms remain largely unexplored. We report herein that prior to occurrence of neoplastic lesions in the azoxymethane-rat model of colon carcinogenesis; the tumor suppressor gene C-terminal Src kinase (Csk) was down-regulated with a concomitant increase in Src activity. Furthermore, pharmacological or genetic (RNA interference) inhibition of Csk resulted in increased proliferation in colon cancer cell lines through the mitogen-activated protein kinase dependent pathway. Thus, we demonstrate, for the first time, that Csk suppression is an important early event in colorectal cancer pathogenesis.
Collapse
Affiliation(s)
- Dhananjay P Kunte
- Department of Internal Medicine, Evanston Northwestern Healthcare, 2650 Ridge Avenue, Evanston, IL 60201, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
BACKGROUND Increased premalignant epithelial microvascular blood content is a common theme in neoplastic transformation; however, demonstration of this phenomenon in colon carcinogenesis has been stymied by methodological limitations. Our group has recently developed a novel optics technology, four dimensional elastic light scattering fingerprinting (4D-ELF), which allows examination of the colonic mucosal architecture with unprecedented accuracy. In this study, we utilised 4D-ELF to probe the preneoplastic colonic microvasculature. METHODS Colonic mucosal blood content was assessed by 4D-ELF at serial preneoplastic time points from azoxymethane (AOM) treated Fisher 344 rats and age matched control animals. We also examined the pretumorigenic intestinal mucosa of the MIN mouse, and compared with wild-type mice. Finally, in a pilot study, we examined superficial blood content from the endoscopically normal mid transverse colon in 37 patients undergoing screening colonoscopy. RESULTS In the AOM treated rat model, augmentation of superficial mucosal and total mucosal/superficial submucosal blood supply preceded the appearance of aberrant crypt foci (ACF) and temporally and spatially correlated with future ACF occurrence. These findings were replicated in MIN mice. The 4D-ELF based results were corroborated with immunoblot analysis for haemoglobin on mucosal scrapings from AOM treated rats. Moreover, 4D-ELF analysis of normal human colonic mucosa indicated that there was a threefold increase in superficial blood in patients who harboured advanced adenomas. CONCLUSION We report, for the first time, that blood content is increased in the colonic microvasculature at the earliest stages of colon carcinogenesis. These findings may provide novel insights into early biological events in colorectal carcinogenesis and have potential applicability for screening.
Collapse
Affiliation(s)
- R K Wali
- Department of Internal Medicine, Evanston-Northwestern Healthcare, Evanston, IL 60201, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
26
|
Abstract
The phenomenon of enhanced backscattering (also known as coherent backscattering), an object of substantial scientific interest, has awaited application to tissue optics for the past two decades. Here we demonstrate, for the first time to our knowledge, depth-resolved spectroscopic elastic light scattering measurements in tissue by use of low-coherence enhanced backscattering (LEBS). We achieve the depth resolution by exploiting the nature of the LEBS peak that contains information about a wide range of tissue depths. We further demonstrate that depth-resolved LEBS spectroscopy has the potential to identify the origin of precancerous transformations in the colon at an early, previously undetectable stage.
Collapse
Affiliation(s)
- Young L Kim
- Department of Biomedical Engineering, Northwestern University, Evanston, Illinois 60208, USA.
| | | | | | | | | | | |
Collapse
|
27
|
Roy HK, Karolski WJ, Wali RK, Ratashak A, Hart J, Smyrk TC. The nonsteroidal anti-inflammatory drug, nabumetone, differentially inhibits beta-catenin signaling in the MIN mouse and azoxymethane-treated rat models of colon carcinogenesis. Cancer Lett 2005; 217:161-9. [PMID: 15617833 DOI: 10.1016/j.canlet.2004.07.042] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2004] [Revised: 07/09/2004] [Accepted: 07/15/2004] [Indexed: 12/16/2022]
Abstract
The mechanisms through which beta-catenin signaling is inhibited during colorectal cancer chemoprevention by nonsteroidal anti-inflammatory agents is incompletely understood. We report that nabumetone decreased uninvolved intestinal mucosal beta-catenin levels in the MIN mouse with a concomitant increase in glycogen synthase kinase (GSK)-3beta levels, an enzyme that targets beta-catenin for destruction. However, in the azoxymethane-treated rat, where beta-catenin is frequently rendered GSK-3beta-insensitive, nabumetone failed to alter beta-catenin levels but did decrease beta-catenin nuclear localization and transcriptional activity as gauged by cyclin D1. In conclusion, we demonstrate that the differential mechanisms for beta-catenin suppression may be determined, at least partly, by GSK-3beta.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Internal Medicine, Evanston-Northwestern Healthcare Research Institute, 1001 University Place, Evanston, IL 60201, USA.
| | | | | | | | | | | |
Collapse
|
28
|
Abstract
Although the phenomenon of coherent backscattering (CBS) in nonbiological media has generated substantial research interest, observing CBS in biological tissue has been extremely difficult. Here we show that the combination of low-spatial-coherence, broadband illumination, and low-temporal-coherence, spectrally resolved detection significantly facilitates CBS observation in biological tissue and other random media with long-transport mean-free path lengths, which have been previously beyond the reach of conventional CBS investigations. Furthermore, we demonstrate that depth-selective, speckle-free, low-coherent backscattering spectroscopy has the potential to diagnose the earliest, previously undetectable, precancerous alterations in the colon by means of probing short light paths.
Collapse
Affiliation(s)
- Young L Kim
- Department of Biomedical Engineering, Northwestern University, #E310, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
| | | | | | | | | |
Collapse
|
29
|
Abstract
Overexpression of the transcriptional repressor, SNAIL, has been implicated in the pathogenesis of a number of malignancies; however, there are no previous reports on the role of SNAIL in colorectal cancers (CRCs). We, therefore, evaluated human CRC specimens for the presence of the SNAIL protein. Immunohistochemical studies were performed using samples obtained from archived CRC paraffin blocks and a tissue array. Tissue sections were probed with a polyclonal antibody to human SNAIL and scored by a gastrointestinal pathologist. SNAIL was not detectable in uninvolved mucosa, but immunoreactivity was evident in 78% of tumors. SNAIL protein expression did not correlate with subsite location or gender, however, SNAIL-positive tumors had an older mean age (58.9 +/- 12.7 versus 49.8 +/- 127; P = 0.028). Furthermore, there was a trend that CRCs with metastatic ability more frequently overexpressed SNAIL (100 versus 65%; P = 0.11). In conclusion, we demonstrate, for the first time, that SNAIL is upregulated in human colon cancer, which potentially may have significance in control of metastasis and possibly serve as a target for chemopreventive agents.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Internal Medicine, Evanston-Northwestern Healthcare, Evanston, Illinois 60201, USA.
| | | | | | | | | |
Collapse
|
30
|
Roy HK, Gulizia J, DiBaise JK, Karolski WJ, Ansari S, Madugula M, Hart J, Bissonnette M, Wali RK. Polyethylene glycol inhibits intestinal neoplasia and induces epithelial apoptosis in Apc(min) mice. Cancer Lett 2004; 215:35-42. [PMID: 15374630 DOI: 10.1016/j.canlet.2004.05.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Revised: 04/27/2004] [Accepted: 05/13/2004] [Indexed: 01/28/2023]
Abstract
Efficacy of a safe and clinically utilized polyethylene glycol formulation (PEG-3350) to suppress intestinal tumors was investigated in the Apc(min) mouse-model of experimental carcinogenesis. Furthermore, based on our previous finding on the induction of apoptosis in HT-29 cells by PEG, we evaluated its ability to stimulate epithelial cell apoptosis in both Apc(min) mouse as well as AOM-treated rat as a potential molecular mechanism of chemoprevention. Twenty-two Apc(min) mice were randomized equally to PEG or vehicle (control) supplementation. Tumors were scored and uninvolved intestinal mucosal apoptosis was assayed using a modified terminal deoxynucleotidyl transferase-mediated nick end-labeling (TUNEL) assay and by immunohistochemical detection of cleaved caspase-3. Supplementation of Apc(min) mice with 10% PEG 3350 (in drinking water) resulted in a 48% (P<0.05) reduction in intestinal tumor burden and induced 2-3 fold increase in mucosal apoptosis. Dietary supplementation of polyethylene glycol (5%) also stimulated colonic mucosal apoptosis 4-5 fold in AOM-treated rats, the regimen that we previously reported to reduce tumor burden by 76% (P<0.05). In summary, we demonstrate, for the first time, that PEG does protect against Apc(min) mouse tumorigenesis. The correlation between pro-apoptotic actions and chemopreventive efficacy of PEG in these models strongly implicates induction of apoptosis as one of the impending mechanisms of chemoprevention.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Medicine, Evanston-Northwestern Healthcare Research Institute, 1001 University Place, Evanston, IL 60201, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Roy HK, Iversen P, Hart J, Liu Y, Koetsier JL, Kim Y, Kunte DP, Madugula M, Backman V, Wali RK. Down-regulation of SNAIL suppresses MIN mouse tumorigenesis: Modulation of apoptosis, proliferation, and fractal dimension. Mol Cancer Ther 2004. [DOI: 10.1158/1535-7163.1159.3.9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
Objectives: Emerging evidence implicates the SNAIL family of transcriptional repressors in cancer development; however, the role of SNAIL in colorectal cancer has not been established. To investigate the importance of SNAIL in colorectal carcinogenesis, we examined the phenotypic and cellular consequences of SNAIL down-regulation in the MIN mouse. Methods: Twenty-eight male MIN mice were randomized to treatment with an antisense phosphorodiamidate morpholino oligomer (AS-PMO) to SNAIL, saline, or a scrambled sequence control for 6 weeks. Tumors were scored and the molecular/cellular effects of anti-SNAIL treatment were evaluated through immunohistochemical analysis of the uninvolved intestinal mucosa for SNAIL and E-cadherin levels along with rates of apoptosis and proliferation. Furthermore, microarchitectural alterations were determined through measurement of fractal dimension. Results: In the uninvolved mucosa, SNAIL AS-PMO treatment moderately decreased SNAIL protein when compared with saline-treated animals (immunohistochemistry scores 3.0 ± 0.8 versus 2.1 ± 0.6, respectively; P = 0.01) with a concomitant increase in E-cadherin expression (1.8 ± 0.6 versus 2.4 ± 0.5; P < 0.05). Anti-SNAIL PMO, but not scramble control, resulted in a significant decrease in both total tumor number and incidence of tumors >2 mm (22% and 54%, respectively; P < 0.05). Furthermore, this was accompanied by an increased apoptosis rate (2-fold), decreased proliferation (3-fold), and normalization of the fractal dimension in the uninvolved intestinal mucosa. Conclusions: We show, for the first time, that SNAIL overexpression is important in intestinal tumorigenesis. While this PMO regimen afforded modest SNAIL suppression and hence tumor reduction, this provides compelling evidence for the role of SNAIL overexpression in colonic neoplasia.
Collapse
Affiliation(s)
- Hemant K. Roy
- 1Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois
| | | | - John Hart
- 3Department of Pathology, University of Chicago Hospitals, Chicago, Illinois; and
| | - Yang Liu
- 4Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Jennifer L. Koetsier
- 1Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois
| | - Young Kim
- 4Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Dhanajay P. Kunte
- 1Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois
| | - Madhavi Madugula
- 1Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois
| | - Vadim Backman
- 4Biomedical Engineering Department, Northwestern University, Evanston, Illinois
| | - Ramesh K. Wali
- 1Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, Evanston, Illinois
| |
Collapse
|
32
|
Roy HK, Iversen P, Hart J, Liu Y, Koetsier JL, Kim Y, Kunte DP, Madugula M, Backman V, Wali RK. Down-regulation of SNAIL suppresses MIN mouse tumorigenesis: modulation of apoptosis, proliferation, and fractal dimension. Mol Cancer Ther 2004; 3:1159-65. [PMID: 15367710] [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: 04/30/2023]
Abstract
OBJECTIVES Emerging evidence implicates the SNAIL family of transcriptional repressors in cancer development; however, the role of SNAIL in colorectal cancer has not been established. To investigate the importance of SNAIL in colorectal carcinogenesis, we examined the phenotypic and cellular consequences of SNAIL down-regulation in the MIN mouse. METHODS Twenty-eight male MIN mice were randomized to treatment with an antisense phosphorodiamidate morpholino oligomer (AS-PMO) to SNAIL, saline, or a scrambled sequence control for 6 weeks. Tumors were scored and the molecular/cellular effects of anti-SNAIL treatment were evaluated through immunohistochemical analysis of the uninvolved intestinal mucosa for SNAIL and E-cadherin levels along with rates of apoptosis and proliferation. Furthermore, microarchitectural alterations were determined through measurement of fractal dimension. RESULTS In the uninvolved mucosa, SNAIL AS-PMO treatment moderately decreased SNAIL protein when compared with saline-treated animals (immunohistochemistry scores 3.0 +/- 0.8 versus 2.1 +/- 0.6, respectively; P=0.01) with a concomitant increase in E-cadherin expression (1.8 +/- 0.6 versus 2.4 +/- 0.5; P < 0.05). Anti-SNAIL PMO, but not scramble control, resulted in a significant decrease in both total tumor number and incidence of tumors >2 mm (22% and 54%, respectively; P < 0.05). Furthermore, this was accompanied by an increased apoptosis rate (2-fold), decreased proliferation (3-fold), and normalization of the fractal dimension in the uninvolved intestinal mucosa. CONCLUSIONS We show, for the first time, that SNAIL overexpression is important in intestinal tumorigenesis. While this PMO regimen afforded modest SNAIL suppression and hence tumor reduction, this provides compelling evidence for the role of SNAIL overexpression in colonic neoplasia.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Internal Medicine, Evanston Northwestern Healthcare Research Institute, 1001 University Place, Evanston, IL 60201, USA.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
33
|
Abstract
Coherent backscattering (CBS) of light in random media has been previously investigated by use of coherent light sources. Here we report a novel method of CBS measurement that combines low spatial coherence, broadband illumination, and spectrally resolved detection. We show that low spatial coherence illumination leads to an anomalously broad CBS peak and a dramatic speckle reduction; the latter is further facilitated by low temporal coherence detection. Thus CBS can be observed in biological tissue and other media that previously were beyond the reach of conventional CBS measurements. We also demonstrate, for the first time to our knowledge, spectroscopic analysis of CBS. CBS spectroscopy may find important applications in probing random media such as biological tissue in which depth-selective measurements are crucial.
Collapse
Affiliation(s)
- Young L Kim
- Department of Biomedical Engineering, Department of Gastroenterology, Northwestern University, Evanston, Illinois 60208, USA.
| | | | | | | | | | | |
Collapse
|
34
|
Roy HK, Liu Y, Wali RK, Kim YL, Kromine AK, Goldberg MJ, Backman V. Four-dimensional elastic light-scattering fingerprints as preneoplastic markers in the rat model of colon carcinogenesis. Gastroenterology 2004; 126:1071-81; discussion 948. [PMID: 15057746 DOI: 10.1053/j.gastro.2004.01.009] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.7] [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 Identification of preneoplastic changes in histologically normal epithelium (the "field effect") could provide a powerful screening tool for colorectal cancer. However, to date, reliable detection has not been possible. We have recently developed a new generation of optical technology, 4-dimensional elastic light-scattering fingerprinting (4D-ELF), which enables us to probe the nanoscale/microscale architecture of living cells. We therefore investigated whether 4D-ELF would be able to identify preneoplastic changes in the colonocytes of the azoxymethane (AOM)-treated rat model of colon carcinogenesis. METHODS Forty-eight Fisher 344 rats were randomized to either 2 weekly injections of AOM or saline. Animals were killed 2-20 weeks after the second injection of AOM. Colons were removed and subjected to 4D-ELF analysis, with a subset undergoing assessment of aberrant crypt foci (ACF). All AOM-treated animals were compared with age-matched saline-treated controls. RESULTS AOM-induced ACF became apparent at approximately 4-6 weeks and continued to increase over time. ACF were predominantly located in the distal colon. At 2 weeks (before development of ACF), there were marked changes in a number of 4D-ELF signatures. The relevance to carcinogenesis of these 4D-ELF-detected microarchitectural abnormalities is supported by their spatial and temporal correlation with subsequent development of ACF. All changes reported were highly statistically significant. CONCLUSIONS We show that probing the nanoscale cellular architecture with 4D-ELF provided an unprecedented tool for detecting the earliest stages of colon carcinogenesis. Future studies are necessary to explore the clinical applicability of this technology and elucidate the biological determinants of these microarchitectural changes.
Collapse
Affiliation(s)
- Hemant K Roy
- Department of Internal Medicine, Evanston-Northwest Healthcare, Northwestern Univerity, IL 60201, USA.
| | | | | | | | | | | | | |
Collapse
|
35
|
Khare S, Cerda S, Wali RK, von Lintig FC, Tretiakova M, Joseph L, Stoiber D, Cohen G, Nimmagadda K, Hart J, Sitrin MD, Boss GR, Bissonnette M. Ursodeoxycholic acid inhibits Ras mutations, wild-type Ras activation, and cyclooxygenase-2 expression in colon cancer. Cancer Res 2003. [PMID: 12839936 DOI: 10.1016/s0016-5085(03)83066-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
K-ras mutations occur frequently in colon cancer and contribute to autonomous growth. In the azoxymethane (AOM) model of colon cancer, in addition to K-ras mutations, we have shown that wild-type (WT) Ras can be activated by upstream pathways, including, e.g., signaling by ErbB receptors. Tumors with mutant or activated WT Ras had increased cyclooxygenase-2 (Cox-2) expression. We have also shown that ursodeoxycholic acid (UDCA) prevented AOM-induced colon cancer and suppressed Cox-2 induction. In this study, we examined the role of Ras in Cox-2 inhibition by UDCA. Rats were fed AIN-76A chow alone, or supplemented with 0.4% UDCA, and received 20 mg/kg AOM i.p. weekly x 2 weeks. At 40 weeks, rats were sacrificed, and tumors were harvested. K-ras mutations were assessed by primer-mediated RFLP, allele-specific oligonucleotide hybridization, and direct DNA sequencing. Ras was immunoprecipitated and defined as activated if [Ras - GTP/(Ras - GTP + Ras - GDP)] was >3 SD above normal colonocytes. Cox-2 mRNA was determined by reverse transcription-PCR, and protein expression was assessed by Western blotting and immunostaining. In the AOM alone group, Ras was activated by mutations in 8 of 30 (27%) tumors, and WT Ras was activated in 7 of 30 (23%) tumors. UDCA significantly suppressed the incidence of tumors with mutant Ras (1 of 31, 3.2%; P < 0.05) and totally abolished the development of tumors with activated WT Ras (0 of 10; P < 0.05). In the AOM alone group, Cox-2 was up-regulated >50-fold in tumors with normal Ras activity and further enhanced in tumors with mutant or signaling-activated Ras. UDCA significantly inhibited Cox-2 protein and mRNA levels in tumors with normal Ras activity. In summary, we have shown for the first time that UDCA suppressed the development of tumors with Ras mutations and blocked activation of WT Ras. Furthermore, UDCA inhibited Cox-2 induction by Ras-dependent and -independent mechanisms.
Collapse
Affiliation(s)
- Sharad Khare
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Khare S, Cerda S, Wali RK, von Lintig FC, Tretiakova M, Joseph L, Stoiber D, Cohen G, Nimmagadda K, Hart J, Sitrin MD, Boss GR, Bissonnette M. Ursodeoxycholic acid inhibits Ras mutations, wild-type Ras activation, and cyclooxygenase-2 expression in colon cancer. Cancer Res 2003; 63:3517-23. [PMID: 12839936] [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: 03/03/2023]
Abstract
K-ras mutations occur frequently in colon cancer and contribute to autonomous growth. In the azoxymethane (AOM) model of colon cancer, in addition to K-ras mutations, we have shown that wild-type (WT) Ras can be activated by upstream pathways, including, e.g., signaling by ErbB receptors. Tumors with mutant or activated WT Ras had increased cyclooxygenase-2 (Cox-2) expression. We have also shown that ursodeoxycholic acid (UDCA) prevented AOM-induced colon cancer and suppressed Cox-2 induction. In this study, we examined the role of Ras in Cox-2 inhibition by UDCA. Rats were fed AIN-76A chow alone, or supplemented with 0.4% UDCA, and received 20 mg/kg AOM i.p. weekly x 2 weeks. At 40 weeks, rats were sacrificed, and tumors were harvested. K-ras mutations were assessed by primer-mediated RFLP, allele-specific oligonucleotide hybridization, and direct DNA sequencing. Ras was immunoprecipitated and defined as activated if [Ras - GTP/(Ras - GTP + Ras - GDP)] was >3 SD above normal colonocytes. Cox-2 mRNA was determined by reverse transcription-PCR, and protein expression was assessed by Western blotting and immunostaining. In the AOM alone group, Ras was activated by mutations in 8 of 30 (27%) tumors, and WT Ras was activated in 7 of 30 (23%) tumors. UDCA significantly suppressed the incidence of tumors with mutant Ras (1 of 31, 3.2%; P < 0.05) and totally abolished the development of tumors with activated WT Ras (0 of 10; P < 0.05). In the AOM alone group, Cox-2 was up-regulated >50-fold in tumors with normal Ras activity and further enhanced in tumors with mutant or signaling-activated Ras. UDCA significantly inhibited Cox-2 protein and mRNA levels in tumors with normal Ras activity. In summary, we have shown for the first time that UDCA suppressed the development of tumors with Ras mutations and blocked activation of WT Ras. Furthermore, UDCA inhibited Cox-2 induction by Ras-dependent and -independent mechanisms.
Collapse
Affiliation(s)
- Sharad Khare
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Wali RK, Kong J, Sitrin MD, Bissonnette M, Li YC. Vitamin D receptor is not required for the rapid actions of 1,25-dihydroxyvitamin D3 to increase intracellular calcium and activate protein kinase C in mouse osteoblasts. J Cell Biochem 2003; 88:794-801. [PMID: 12577313 DOI: 10.1002/jcb.10432] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [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: 11/09/2022]
Abstract
The rapid, non-genomic actions of 1,25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] have been well described, however, the role of the nuclear vitamin D receptor (VDR) in this pathway remains unclear. To address this question, we used VDR(+/+) and VDR(-/-) osteoblasts isolated from wild-type and VDR null mice to study the increase in intracellular calcium ([Ca(2+)](i)) and activation of protein kinase C (PKC) induced by 1,25(OH)(2)D(3). Within 1 min of 1,25(OH)(2)D(3) (100 nM) treatment, an increase of 58 and 53 nM in [Ca(2+)](i) (n = 3) was detected in VDR(+/+) and VDR(-/-) cells, respectively. By 5 min, 1,25(OH)(2)D(3) caused a 2.1- and 1.9-fold increase (n = 6) in the phosphorylation of PKC substrate peptide acetylated-MBP(4-14) in VDR(+/+) and VDR(-/-) osteoblasts. The 1,25(OH)(2)D(3)-induced phosphorylation was abolished by GF109203X, a general PKC inhibitor, in both cell types, confirming that the secosteroid induced PKC activity. Moreover, 1,25(OH)(2)D(3) treatment resulted in the same degree of translocation of PKC-alpha and PKC-delta, but not of PKC-zeta, from cytosol to plasma membrane in both VDR(+/+) and VDR(-/-) cells. These experiments demonstrate that the 1,25(OH)(2)D(3)-induced rapid increases in [Ca(2+)](i) and PKC activity are neither mediated by, nor dependent upon, a functional nuclear VDR in mouse osteoblasts. Thus, VDR is not essential for these rapid actions of 1,25(OH)(2)D(3) in osteoblasts.
Collapse
Affiliation(s)
- Ramesh K Wali
- Evanston Northwestern Healthcare, Evanston, Illinois 60201, USA
| | | | | | | | | |
Collapse
|
38
|
Wali RK, Khare S, Tretiakova M, Cohen G, Nguyen L, Hart J, Wang J, Wen M, Ramaswamy A, Joseph L, Sitrin M, Brasitus T, Bissonnette M. Ursodeoxycholic acid and F(6)-D(3) inhibit aberrant crypt proliferation in the rat azoxymethane model of colon cancer: roles of cyclin D1 and E-cadherin. Cancer Epidemiol Biomarkers Prev 2002; 11:1653-62. [PMID: 12496057] [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: 02/28/2023] Open
Abstract
We have previously demonstrated that ursodeoxycholic acid(UDCA) and a fluorinated analogue of vitamin D(3), F(6)-D(3),inhibited colonic carcinogenesis in the azoxymethane (AOM) model. Generalized colonic mucosal hyperproliferation and aberrant crypt foci (ACF) are intermediate biomarkers of colon cancer. Using these biomarkers, in this study we examined the anticarcinogenic mechanisms of these chemopreventive agents. Rats were maintained on AIN-76A chow or supplemented with 0.4% UDCA or F(6)-D(3) (2.5 nmol/kg chow) and treated weekly with AOM 20 mg i.p./kg wt or saline x 2 weeks. F(6)-D(3) was continued for an additional 2 weeks and UDCA for the duration of the study. At 40 weeks, animals received bromodeoxyuridine (BrdUrd) i.p. 2 h before sacrifice. A portion of each tumor was fixed in formalin and the remainder flash frozen. Colons were divided longitudinally and half-fixed in formalin and half in ethanol. The size and location of methylene blue-stained ACF were recorded. Cell proliferation (BrdUrd labeling) and apoptosis (terminal deoxynucleotidyl transferase-mediated nick end labeling assay) were measured in colonic crypts and tumors. Protein expression levels of several regulators of cell proliferation were analyzed by immunostaining and Western blotting. Colonic crypt cyclin D1 and E-cadherin mRNA levels were measured by real-time PCR. In saline injected controls, neither UDCA nor F(6)-D(3) alone had any effect on cytokinetic parameters or on the expression of mitogenic regulators. AOM significantly increased the proliferation (percentage of BrdUrd-positive cells) of both ACF (23.1 +/- 1.7%) and non-ACF crypts (17.6 +/- 1.6%), compared with normal colonic crypts (4.5 +/- 0.8%; P < 0.05). This hyperproliferation was accompanied by a 5-fold increase in cyclin D1 and >50% decrease in E-cadherin protein (P < 0.05) in ACF, both of which are predicted to be growth-enhancing alterations. UDCA and F(6)-D(3) significantly (P < 0.05) inhibited AOM-induced crypt cell hyperproliferation, ACF development, and tumor burden. These chemopreventive agents also significantly blocked AOM-induced alterations in cyclin D1 and E-cadherin protein in ACF and tumors. In ACF, changes in mRNA levels of cyclin D1, but not E-cadherin, paralleled alterations in protein expression. Cyclooxygenase-2 and inducible nitric oxide synthase were increased in AOM tumors but not in ACF, and these changes were blocked by UDCA and F(6)-D(3). UDCA and F(6)-D(3) significantly inhibited ACF development and hyperproliferation, in part, by preventing carcinogen-induced alterations in cyclin D1 and E-cadherin. In established tumors, UDCA and F(6)-D(3) also limited inductions of cyclooxygenase-2 and inducible nitric oxide synthase, which together with their effects on cyclin D1 and E-cadherin, contribute to their chemopreventive actions.
Collapse
Affiliation(s)
- Ramesh K Wali
- Department of Medicine, University of Chicago Hospitals and Clinics, Chicago, Illinois 60637, USA
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
39
|
Wali RK, Stoiber D, Nguyen L, Hart J, Sitrin MD, Brasitus T, Bissonnette M. Ursodeoxycholic acid inhibits the initiation and postinitiation phases of azoxymethane-induced colonic tumor development. Cancer Epidemiol Biomarkers Prev 2002; 11:1316-21. [PMID: 12433708] [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: 02/27/2023] Open
Abstract
Colonic tumorigenesis involves the processes of initiation and promotion/progression from normal epithelial cells to tumors. Studies in both humans and experimental models of colon cancer indicate that secondary bile acids promote tumor development. In contrast, we have demonstrated previously that another bile acid, ursodeoxycholic acid (UDCA), inhibits the development of azoxymethane (AOM)-induced colon cancer in rats. More recently, we have shown that UDCA inhibits AOM-induced hyperproliferation, and aberrant crypt formation and growth. In our previous studies, we supplemented UDCA throughout the experiment. The efficacy of a chemopreventive agent may depend on the timing of administration, which has important clinical implications. In the present investigation, we examined the ability of UDCA, when administered only in the initiation or the promotion/progression phase, to block tumor development. Male Fisher 344 rats were divided in a 2 x 3 factorial design, with animals receiving AOM or vehicle, and fed an unsupplemented diet or diet supplemented with 0.4% UDCA in the initiation or promotion/progression phase. Thirty-two weeks later, rats were sacrificed and tumor histology determined, and colons were examined for aberrant crypt foci (ACF). In the carcinogen-treated dietary control group, tumor incidence was 72.3%, and tumor multiplicity was 1.9 tumors per tumor-bearing rat. UDCA, in the initiation or promotion/progression phase, significantly decreased tumor incidence to 46.2% and 38.4% (P < 0.05), respectively; and tumor multiplicity to 1.4 and 1.3 tumors per tumor-bearing rat (P < 0.05), respectively. UDCA did not alter tumor size, histology, or location, although there were trends for smaller tumors and less advanced histological grades in the group given UDCA during the promotion phase. UDCA, in the initiation but not the promotion phase, inhibited ACF formation and growth. In summary, UDCA significantly inhibited AOM-induced colonic carcinogenesis during either tumor initiation or in the promotion/progression phase. In contrast, UDCA inhibited ACF formation only when administered in the initiation phase, suggesting that the mechanisms of chemoprevention by this bile acid differ in these two phases.
Collapse
Affiliation(s)
- Ramesh K Wali
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | | | | | |
Collapse
|
40
|
Bissonnette M, Khare S, von Lintig FC, Wali RK, Nguyen L, Zhang Y, Hart J, Skarosi S, Varki N, Boss GR, Brasitus TA. Mutational and nonmutational activation of p21ras in rat colonic azoxymethane-induced tumors: effects on mitogen-activated protein kinase, cyclooxygenase-2, and cyclin D1. Cancer Res 2000; 60:4602-9. [PMID: 10969813] [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: 02/17/2023]
Abstract
Azoxymethane (AOM)-induced colonic carcinogenesis involves a number of mutations, including those in the K-ras gene and CTNNB1, that codes for beta-catenin. Prior in vitro studies have also demonstrated that wild type p21(K-ras) can be activated by epigenetic events. We identified 15 K-ras mutations in 14 of 84 AOM-induced colonic tumors by three independent methods. By single strand conformational polymorphism, we also observed mutations in 22 of 68 tumors in exon 3 of CTNNB1. A highly sensitive method was then used to measure p21ras activation levels. All tumors assayed possessing K-ras mutations had significantly higher p21ras activation levels (8.8 +/- 1.5%; n = 13) compared with that of control colon (3.7 +/- 0.4; n = 6; P < 0.05) or tumors without such mutations (4.2 +/- 0.4%; n = 70; P < 0.05). Among tumors with wild-type K-ras, there was a subset of tumors (18 of 70) that had significantly higher p21ras activation levels (8.0 +/- 0.9%; n = 18) compared with control colons. In three of four tumors examined with activated wild-type p21ras, we observed increased c-erbB-2 receptor expression and decreased Ras-GAP expression. In contrast, only one of eight tumors examined with wild-type ras and nonactivated p21ras demonstrated these alterations. Mitogen-activated protein kinase (MAPK) activation and cyclooxygenase-2 (COX-2) expression were increased in tumors with mutated or activated wild-type p21ras, compared with their nonactivated counterparts. Although beta-catenin mutations did not alter COX-2 expression or MAPK activity, mutations in either K-ras or beta-catenin significantly increased cyclin D1 expression. In contrast, in tumors with wild-type but activated p21-ras, cyclin D1 expression was not enhanced. Thus, the spectrum of changes in MAPK, COX-2, and cyclin D1 is distinct among tumors with ras or beta-catenin mutations or nonmutational activation of p21ras.
Collapse
|
41
|
|
42
|
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: 15] [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.
Collapse
Affiliation(s)
- R K Wali
- Department of Medicine, University of Chicago, Chicago, IL 60637, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
43
|
Abstract
Hypertension is the most common public health challenge in the United States because of its prevalence and associated increase in comorbid cardiovascular diseases. Yearly expenses related directly or indirectly to the treatment and detection of hypertension in the United States are approximately $10 billion, excluding the enormous yearly financial burden of $259 billion and the social burden from heart disease and stroke, which remain the first and third leading causes of death, respectively, in the United States. Despite the importance of these observations, blood pressure is poorly controlled in the United States.
Collapse
Affiliation(s)
- R K Wali
- Division of Nephrology N3W143, University of Maryland Hospital, 22 S. Greene Street, Baltimore, MD 21201, USA
| | | |
Collapse
|
44
|
Khare S, Bissonnette M, Scaglione-Sewell B, Wali RK, Sitrin MD, Brasitus TA. 1,25-dihydroxyvitamin D3 and TPA activate phospholipase D in Caco-2 cells: role of PKC-alpha. Am J Physiol 1999; 276:G993-G1004. [PMID: 10198344 DOI: 10.1152/ajpgi.1999.276.4.g993] [Citation(s) in RCA: 8] [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] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] and 12-O-tetradecanoylphorbol 13-acetate (TPA) both activated phospholipase D (PLD) in Caco-2 cells. GF-109203x, an inhibitor of protein kinase C (PKC) isoforms, inhibited this activation by both of these agonists. 1,25(OH)2D3 activated PKC-alpha, but not PKC-beta1, -betaII, -delta, or -zeta, whereas TPA activated PKC-alpha, -beta1, and -delta. Chronic treatment with TPA (1 microM, 24 h) significantly reduced the expression of PKC-alpha, -betaI, and -delta and markedly reduced the ability of 1,25(OH)2D3 or TPA to acutely stimulate PLD. Removal of Ca2+ from the medium, as well as preincubation of cells with Gö-6976, an inhibitor of Ca2+-dependent PKC isoforms, significantly reduced the stimulation of PLD by 1,25(OH)2D3 or TPA. Treatment with 12-deoxyphorbol-13-phenylacetate-20-acetate, which specifically activates PKC-betaI and -betaII, however, failed to stimulate PLD. In addition, the activation of PLD by 1,25(OH)2D3 or TPA was markedly reduced or accentuated in stably transfected cells with inhibited or amplified PKC-alpha expression, respectively. Taken together, these observations indicate that PKC-alpha is intimately involved in the stimulation of PLD in Caco-2 cells by 1,25(OH)2D3 or TPA.
Collapse
Affiliation(s)
- S Khare
- Department of Medicine, University of Chicago, Chicago, Illinois 60637, USA
| | | | | | | | | | | |
Collapse
|
45
|
Bolt MJ, Mailloux RJ, Rasenick MM, Wali RK, Skarosi S, Bissonnette M, Brasitus TA, Sitrin MD. Expression of G protein alpha subunits in normal rat colon and in azoxymethane-induced colonic neoplasms. Gastroenterology 1998; 115:1494-503. [PMID: 9834277 DOI: 10.1016/s0016-5085(98)70028-9] [Citation(s) in RCA: 7] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
BACKGROUND & AIMS Heterotrimeric G proteins are important in growth-regulating signal transduction. The aim of this study was to characterize the relative expression of G protein alpha subunits in rat colonocytes, colonocyte antipodal plasma membranes, and colonic neoplasms. METHODS Antipodal plasma membranes were prepared from isolated colonocytes. Azoxymethane was administered to rats to induce colonic neoplasms. K-ras mutations in the neoplasms were determined by oligonucleotide hybridization and confirmed by primer mediated-restriction fragment length polymorphism. Colonocyte and tumor homogenates or membranes were probed for Galpha subunits by Western blotting with isoform-specific antibodies. RESULTS The expressions of Galphai2, alphai3, and alphaq/11 were significantly enriched in the basolateral compared with brush border fraction of colonic antipodal plasma membranes. In neoplasms without K-ras mutations, the expression of Galphai2 increased 4-fold, Galphas(long) increased 2.5-fold, and Galphai3 increased 1.5-2-fold. Expression did not differ among tumor grades. K-ras mutations were associated with lowered expression of G proteins, especially Galphao. CONCLUSIONS In colonocytes, Galpha subunits are localized primarily in basolateral plasma membranes. The increased expressions of Galphai2 and, to a lesser degree, Galphai3 and Galphas(long) in tumors was independent of tumor grade but was modulated by the presence of K-ras mutations.
Collapse
Affiliation(s)
- M J Bolt
- Department of Medicine, University of Chicago, Chicago, Illinois, 60637, USA
| | | | | | | | | | | | | | | |
Collapse
|
46
|
Wali RK, Bissonnette M, Skarosi S, Khare S, Sitrin M, Brasitus TA. 1,25-Dihydroxyvitamin D3 targets PKC-betaII but not PKC-alpha to the basolateral plasma membranes of rat colonocytes. Biochem Biophys Res Commun 1998; 250:48-52. [PMID: 9735329 DOI: 10.1006/bbrc.1998.9260] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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] [Indexed: 11/22/2022]
Abstract
Prior studies by our laboratory have shown that 1, 25-dihydroxyvitamin D3 activated PKC-alpha, but not PKC-delta, -epsilon, or -zeta, in normal rat colonocytes. In the present studies we demonstrate for the first time that this secosteroid also activated PKC-betaII, another DAG- and Ca2+-dependent PKC isoform recently shown to be present in these cells. Moreover, this activation of PKC-betaII by 1,25-dihydroxyvitamin D3 treatment of isolated colonocytes was shown to be lost in cells from vitamin D-deficient rats and, at least partially, restored by repleting these animals with this secosteroid for 7 days. Under basal conditions, the expression of PKC-alpha and -betaII in brush-border membranes was comparable to their respective expression in basolateral plasma membranes of rat colonocytes. In contrast, the expression of PKC-delta was significantly greater in brush-border membranes, whereas PKC-epsilon and -zeta were enriched in the basolateral plasma membranes. Furthermore, 1,25-dihydroxyvitamin D3 specifically induced the translocation of PKC-betaII, but not PKC-alpha, to the basolateral, but not brush-border plasma membranes of rat colonocytes, via a pp60(c-src)-dependent mechanism.
Collapse
Affiliation(s)
- R K Wali
- Department of Medicine, University of Chicago, Chicago, Illinois, 60637, USA
| | | | | | | | | | | |
Collapse
|
47
|
|
48
|
Scaglione-Sewell B, Abraham C, Bissonnette M, Skarosi SF, Hart J, Davidson NO, Wali RK, Davis BH, Sitrin M, Brasitus TA. Decreased PKC-alpha expression increases cellular proliferation, decreases differentiation, and enhances the transformed phenotype of CaCo-2 cells. Cancer Res 1998; 58:1074-81. [PMID: 9500474] [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: 02/06/2023]
Abstract
Previous studies have shown that PKC-alpha protein expression is decreased in sporadic human colon cancers, as well as in colonic tumors of rats induced by chemical carcinogens. To elucidate the potential role of PKC-alpha on several phenotypic characteristics of colon cancer cells, we have transfected cDNAs for PKC-alpha in sense or antisense orientations into CaCo-2 cells, a human colonic adenocarcinoma cell line. Transfected clones were isolated that demonstrated approximately 3-fold increases (sense transfectants) and approximately 95% decreases (antisense transfectants) in PKC-alpha expression with no significant alterations in other PKC isoforms. Transfection of CaCo-2 cells with PKC-alpha in the antisense orientation resulted in enhanced proliferation and decreased differentiation, as well as in a more aggressive transformed phenotype compared with empty vector-transfected control cells. In contrast, cells transfected with PKC-alpha cDNA in the sense orientation demonstrated decreased proliferation, enhanced differentiation, and an attenuated tumor phenotype compared with these control cells. These data show that alterations in the expression of PKC-alpha induce changes in the proliferation, differentiation, and tumorigenicity of CaCo-2 cells. Furthermore, these findings indicate that loss of PKC-alpha expression in sporadic human and chemically induced colonic cancers may confer a relative growth advantage during colonic malignant transformation.
Collapse
|
49
|
Khare S, Bolt MJ, Wali RK, Skarosi SF, Roy HK, Niedziela S, Scaglione-Sewell B, Aquino B, Abraham C, Sitrin MD, Brasitus TA, Bissonnette M. 1,25 dihydroxyvitamin D3 stimulates phospholipase C-gamma in rat colonocytes: role of c-Src in PLC-gamma activation. J Clin Invest 1997; 99:1831-41. [PMID: 9109427 PMCID: PMC508007 DOI: 10.1172/jci119350] [Citation(s) in RCA: 58] [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] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Our laboratory has previously demonstrated that 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) rapidly stimulated polyphosphoinositide (PI) hydrolysis, raised intracellular Ca2+, and activated two Ca2+-dependent protein kinase C (PKC) isoforms, PKC-alpha and -betaII in the rat large intestine. We also showed that the direct addition of 1,25(OH)2D3 to isolated colonic membranes failed to stimulate PI hydrolysis, but required secosteroid treatment of intact colonocytes, suggesting the involvement of a soluble factor. Furthermore, this PI hydrolysis was restricted to the basal lateral plasma membrane of these cells. In the present studies, therefore, we examined whether polyphosphoinositide-phospholipase C-gamma (PI-PLC-gamma), a predominantly cytosolic isoform of PI-PLC, was involved in the hydrolysis of colonic membrane PI by 1,25(OH)2D3. This isoform has been shown to be activated and membrane-associated by tyrosine phosphorylation. We found that 1,25(OH)2D3 caused a significant increase in the biochemical activity, particulate association, and the tyrosine phosphorylation of PLC-gamma, specifically in the basal lateral membranes. This secosteroid also induced a twofold increase in the activity of Src, a proximate activator of PLC-gamma in other cells, with peaks at 1 and 9 min in association with Src tyrosine dephosphorylation. 1,25(OH)2D3 also increased the physical association of activated c-Src with PLC-gamma. In addition, Src isolated from colonocytes treated with 1,25(OH)2D3, demonstrated an increased ability to phosphorylate exogenous PLC-gamma in vitro. Inhibition of 1,25(OH)2D3-induced Src activation by PP1, a specific Src family protein tyrosine kinase inhibitor, blocked the ability of this secosteroid to stimulate the translocation and tyrosine phosphorylation of PLC-gamma in the basolateral membrane (BLM). Src activation was lost in D deficiency, and was reversibly restored with the in vivo repletion of 1,25(OH)2D3. These studies demonstrate for the first time that 1,25(OH)2D3 stimulates PLC-gamma as well as c-Src in rat colonocytes, and indicate that PLC-gamma is a direct substrate of secosteroid-activated c-Src in these cells.
Collapse
Affiliation(s)
- S Khare
- Department of Medicine of the University of Chicago, Illinois 60637, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Wali RK, Bissonnette M, Khare S, Aquino B, Niedziela S, Sitrin M, Brasitus TA. Protein kinase C isoforms in the chemopreventive effects of a novel vitamin D3 analogue in rat colonic tumorigenesis. Gastroenterology 1996; 111:118-26. [PMID: 8698190 DOI: 10.1053/gast.1996.v111.pm8698190] [Citation(s) in RCA: 16] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND & AIMS We recently showed that dietary supplementation with an analogue of 1alpha,25-dihydroxy-vitamin D3, 1alpha,25-dihydroxy-16-ene-23-yne-26,27 F6-vitamin D3 (RO24-5531), reduced the incidence of colonic tumors in rats treated with azoxymethane (AOM). The aim of this study was to determine whether alterations in specific isoforms of protein kinase C (PKC) are involved in this phenomenon. METHODS Protein abundance and subcellular distribution of several PKC isoforms were examined and compared in AOM-induced tumors of rats fed control and RO24-5531-supplemented diets. RESULTS In both AOM-induced colonic adenomas and carcinomas, a significant down-regulation of PKC-alpha, -delta, and -zeta and an up-regulation of PKC-beta11 were found compared with control colonocytes. Dietary RO24-5531 preserved the expression of PKC-zeta and increased the abundance of PKC-epsilon in carcinogen-induced adenomas. CONCLUSIONS Because identical changes in specific isoforms of PKC were found in AOM-induced adenomas and carcinomas, these alterations may be involved in the early stage(s) of colonic malignant transformation. Moreover, the ability of RO24-5531 to block the changes in PKC-zeta induced by AOM, as well as to up-regulate PKC-epsilon, may underlie its ability to prevent adenomas from progressing to carcinomas.
Collapse
Affiliation(s)
- R K Wali
- Department of Medicine, University of Chicago Hospitals and Clinics, Illinois. USA
| | | | | | | | | | | | | |
Collapse
|