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Ko SH, Baeg MK, Ko SY, Jung HS, Kim P, Choi MG. Obesity and Metabolic Unhealthiness Have Different Effects on Colorectal Neoplasms. J Clin Endocrinol Metab 2017; 102:2762-2769. [PMID: 28510711 DOI: 10.1210/jc.2017-00152] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Accepted: 05/02/2017] [Indexed: 02/07/2023]
Abstract
CONTEXT Obesity and insulin resistance are risk factors for colorectal neoplasms (CRN), but data regarding metabolic status, obesity, and CRN are lacking. OBJECTIVE To investigate the relationship between metabolic status, obesity, and CRN in Koreans who underwent colonoscopy. DESIGN Retrospective, cross-sectional. PARTICIPANTS Subjects were divided based on metabolic and obesity criteria, as follows: metabolically healthy nonobese (MHNO), metabolically healthy obese (MHO), metabolically unhealthy nonobese (MUNO), and metabolically unhealthy obese (MUO). MAIN OUTCOME MEASURES Multiple regression was used to identify CRN and advanced CRN risk factors, with the MHNO group as reference. RESULTS A total of 10,235 subjects was included, as follows: 5096 MHNO, 1538 MHO, 1746 MUNO, and 1855 MUO. Of these, 3297 had CRN (32.2%), and 434 (4.2%) had advanced CRN. Number of subjects with CRN in each group were: MHNO 25.8%, MHO 33.9%, MUNO 38.9%, and MUO 42.0% (P for trend < 0.001). Risk of CRN was increased in the MHO [odds ratio (OR) 1.239, 95% confidence interval (CI) 1.082 to 1.418, P = 0.002], the MUNO (OR 1.233, 95% CI 1.086 to 1.400, P = 0.001), and the MUO groups (OR 1.510, 95% CI 1.338 to 1.706, P < 0.001), whereas risk of advanced CRN was increased in the MUNO (OR 1.587, 95% CI 1.222 to 2.062, P = 0.001) and the MUO groups (OR 1.456, 95% CI 1.116 to 1.900, P = 0.006). CONCLUSIONS Obesity increased CRN risk with metabolically unhealthy status adding risk. For advanced CRN, metabolically unhealthy status increased the risk but obesity did not.
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Affiliation(s)
- Sun-Hye Ko
- Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul 05505, South Korea
| | - Myong Ki Baeg
- Department of Internal Medicine, International St. Mary's Hospital, College of Medicine, Catholic Kwandong University, Incheon 22711, South Korea
| | - Seung Yeon Ko
- Department of Surgery, Incheon St. Mary's Hospital, College of Medicine, Catholic University of Korea, Incheon 21431, South Korea
| | - Hee Sun Jung
- Department of Health Promotion, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul 06591, South Korea
| | - Pumsoo Kim
- Department of Internal Medicine, International St. Mary's Hospital, College of Medicine, Catholic Kwandong University, Incheon 22711, South Korea
| | - Myung-Gyu Choi
- Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, Catholic University of Korea, Seoul 06591, South Korea
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Nieto A, Sánchez MA, Martínez E, Rollán E. Immunohistochemical Expression of p53, Fibroblast Growth Factor-b, and Transforming Growth Factor-α in Feline Vaccine-associated Sarcomas. Vet Pathol 2016; 40:651-8. [PMID: 14608018 DOI: 10.1354/vp.40-6-651] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Fifty feline sarcomas associated with vaccine-site injection were evaluated to determine the immunohistochemical expression of p53 protein, basic fibroblast growth factor (FGF-b), and transforming growth factor-α (TGF-α). Forty-one tumors (82%) were fibrosarcomas (FS), eight (16%) were malignant fibrous histiocytomas (MFH), and one (2%) was a chondrosarcoma (CS). Overexpression of p53 protein was observed in the nuclei of tumor cells in 28 (56%) sarcomas; FGF-b expression was found in the cytoplasm of tumor cells in 40 (80%) feline sarcomas, but the staining was more intense in the spindle-shaped cells of FS than in polygonal or round cells of MFH. The single CS faintly expressed FGF-b. The majority of feline vaccine-associated sarcomas (43 of 50, 86%) expressed moderate or intense staining for TGF-α in the cytoplasm of tumor cells. Heterogeneous immunolabeling for p53, FGF-b, and TGF-α was present in neoplastic, multinucleated giant cells. Intense expression of FGF-b was statistically associated with younger cats ( P < 0.01) and with tumors with nodular growth patterns ( P = 0.02). In addition, sarcomas negative for p53 protein expressed FGF-b more frequently than did p53-positive tumors ( P = 0.04). The frequency of FGF-b immunostaining was significantly higher in sarcomas with intense expression of TGF-α ( P = 0.05). Immunohistochemical detection of p53 protein, FGF-b, and TGF-α suggests that these growth-regulating proteins may play different roles in the development of sarcomas associated with vaccine sites.
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Affiliation(s)
- A Nieto
- Departamento de Patología Animal II, Facultad de Veterinaria, Universidad Complutense de Madrid, 28040 Madrid, Spain
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Agarwal E, Chaudhuri A, Leiphrakpam PD, Haferbier KL, Brattain MG, Chowdhury S. Akt inhibitor MK-2206 promotes anti-tumor activity and cell death by modulation of AIF and Ezrin in colorectal cancer. BMC Cancer 2014; 14:145. [PMID: 24581231 PMCID: PMC3941258 DOI: 10.1186/1471-2407-14-145] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Accepted: 02/20/2014] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND There is extensive evidence for the role of aberrant cell survival signaling mechanisms in cancer progression and metastasis. Akt is a major component of cell survival-signaling mechanisms in several types of cancer. It has been shown that activated Akt stabilizes XIAP by S87 phosphorylation leading to survivin/XIAP complex formation, caspase inhibition and cytoprotection of cancer cells. We have reported that TGFβ/PKA/PP2A-mediated tumor suppressor signaling regulates Akt phosphorylation in association with the dissociation of survivin/XIAP complexes leading to inhibition of stress-dependent induction of cell survival. METHODS IGF1R-dependent colon cancer cells (GEO and CBS) were used for the study. Effects on cell proliferation and cell death were determined in the presence of MK-2206. Xenograft studies were performed to determine the effect of MK-2206 on tumor volume. The effect on various cell death markers such as XIAP, survivin, AIF, Ezrin, pEzrin was determined by western blot analysis. Graph pad 5.0 was used for statistical analysis. P < 0.05 was considered significant. RESULTS We characterized the mechanisms by which a novel Akt kinase inhibitor MK-2206 induced cell death in IGF1R-dependent colorectal cancer (CRC) cells with upregulated PI3K/Akt signaling in response to IGF1R activation. MK-2206 treatment generated a significant reduction in tumor growth in vivo and promoted cell death through two mechanisms. This is the first report demonstrating that Akt inactivation by MK-2206 leads to induction of and mitochondria-to-nuclear localization of the Apoptosis Inducing Factor (AIF), which is involved in caspase-independent cell death. We also observed that exposure to MK-2206 dephosphorylated Ezrin at the T567 site leading to the disruption of Akt-pEzrin-XIAP cell survival signaling. Ezrin phosphorylation at this site has been associated with malignant progression in solid tumors. CONCLUSION The identification of these 2 novel mechanisms leading to induction of cell death indicates MK-2206 might be a potential clinical candidate for therapeutic targeting of the subset of IGF1R-dependent cancers in CRC.
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Affiliation(s)
| | | | | | | | - Michael G Brattain
- Eppley Cancer Center, University of Nebraska Medical Center, 985950 Nebraska Medical Center, Omaha, Nebraska 68198-5950, USA.
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Chowdhury S, Ongchin M, Sharratt E, Dominguez I, Wang J, Brattain MG, Rajput A. Intra-tumoral heterogeneity in metastatic potential and survival signaling between iso-clonal HCT116 and HCT116b human colon carcinoma cell lines. PLoS One 2013; 8:e60299. [PMID: 23560089 PMCID: PMC3613369 DOI: 10.1371/journal.pone.0060299] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 02/25/2013] [Indexed: 02/02/2023] Open
Abstract
Background Colorectal cancer (CRC) metastasis is a leading cause of cancer-related deaths in the United States. The molecular mechanisms underlying this complex, multi-step pathway are yet to be completely elucidated. Recent reports have stressed the importance of intra-tumoral heterogeneity in the development of a metastatic phenotype. The purpose of this study was to characterize the intra-tumoral phenotypic heterogeneity between two iso-clonal human colon cancer sublines HCT116 and HCT116b on their ability to undergo metastatic colonization and survive under growth factor deprivation stress (GFDS). Materials and Methods HCT116 and HCT116b cells were transfected with green fluorescence protein and subcutaneously injected into BALB/c nude male mice. Once xenografts were established, they were excised and orthotopically implanted into other male BALB/c nude mice using microsurgical techniques. Animal tissues were studied for metastases using histochemical techniques. Microarray analysis was performed to generate gene signatures associated with each subline. In vitro assessment of growth factor signaling pathway was performed under GFDS for 3 and 5 days. Results Both HCT116 and HCT116b iso-clonal variants demonstrated 100% primary tumor growth, invasion and peritoneal spread. However, HCT116 was highly metastatic with 68% metastasis observed in liver and/or lungs compared to 4% in HCT116b. Microarray analysis revealed an upregulation of survival and metastatic genes in HCT116 cells compared to HCT116b cells. In vitro analysis showed that HCT116 upregulated survival and migratory signaling proteins and downregulated apoptotic agents under GFDS. However, HCT116b cells effectively showed the opposite response under stress inducing cell death. Conclusions We demonstrate the importance of clonal variation in determining metastatic potential of colorectal cancer cells using the HCT116/HCT116b iso-clonal variants in an orthotopic metastatic mouse model. Determination of clonal heterogeneity in patient tumors can serve as useful tools to identify clinically relevant biomarkers for diagnostic and therapeutic assessment of metastatic colorectal cancer.
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Affiliation(s)
- Sanjib Chowdhury
- Eppley Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
- * E-mail: (AR); (SC)
| | - Melanie Ongchin
- Department of Surgery, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Elizabeth Sharratt
- Department of Pharmacology & Therapeutics, Roswell Park Cancer Institute, Buffalo, New York, United States of America
| | - Ivan Dominguez
- Department of Surgery, State University of New York at Buffalo, Buffalo, New York, United States of America
| | - Jing Wang
- Eppley Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Michael G. Brattain
- Eppley Cancer Center, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Ashwani Rajput
- Division of Surgical Oncology, Department of Surgery, University of New Mexico Health Sciences Center, Albuquerque, New Mexico, United States of America
- * E-mail: (AR); (SC)
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Barba M, Sperati F, Stranges S, Carlomagno C, Nasti G, Iaffaioli V, Caolo G, Mottolese M, Botti G, Terrenato I, Vici P, Serpico D, Giordano A, D’Aiuto G, Crispo A, Montella M, Capurso G, Delle Fave G, Fuhrman B, Botti C, De Placido S. Fasting glucose and treatment outcome in breast and colorectal cancer patients treated with targeted agents: results from a historic cohort. Ann Oncol 2012; 23:1838-45. [PMID: 22100694 PMCID: PMC3387821 DOI: 10.1093/annonc/mdr540] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 10/03/2011] [Accepted: 10/05/2011] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND We investigated pretreatment fasting glucose as a predictor of patients' important outcomes in breast and colorectal cancers undergoing targeted therapies. PATIENTS AND METHODS In a historic cohort of 202 breast and 218 colorectal cancers treated with targeted agents from 1998 to 2009, we used the Kaplan-Meier method and the log-rank test to estimate survival through tertiles of fasting glucose and the Cox proportional hazards model for multivariate analysis stratified by primary site of cancer and including gender, age and body mass index. RESULTS The median follow-up was 20 months (1-128). At 60 months, 65% of patients in the lowest tertile of fasting glucose did not experiment disease progression compared with 34% in the highest tertile (P=0.001). Seventy-six percent of females in the lowest tertile showed no progression compared with 49% in the top tertiles (P=0.015). In multivariate analysis, fasting glucose was a significant predictor of time to disease progression only in breast cancer patients in the first tertile compared with the third (P=0.017). CONCLUSIONS We found evidence of a predictive role of pretreatment fasting glucose in the development of resistance in breast cancer patients treated with targeted agents. Prospective studies are warranted to confirm our findings.
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Affiliation(s)
- M. Barba
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, Temple University, Philadelphia, USA
- Human Health Foundation, Spoleto-Terni
| | - F. Sperati
- Department of Epidemiology, Regina Elena National Cancer Institute, Rome, Italy
| | - S. Stranges
- Health Sciences Research Institute, University of Warwick Medical School, Coventry, UK
| | - C. Carlomagno
- Department of Medical Oncology and Endocrinology, Federico II Medical School of Naples, Naples
| | - G. Nasti
- Department of Colorectal Medical Oncology, G. Pascale National Cancer Institute, Naples
| | - V. Iaffaioli
- Department of Colorectal Medical Oncology, G. Pascale National Cancer Institute, Naples
| | - G. Caolo
- Department of Epidemiology, Regina Elena National Cancer Institute, Rome, Italy
| | - M. Mottolese
- Department of Pathology, Regina Elena National Cancer Institute, Rome
| | - G. Botti
- Departmental Unit of Pathology and Cytopathology, G. Pascale National Cancer Institute, Naples
| | - I. Terrenato
- Department of Epidemiology, Regina Elena National Cancer Institute, Rome, Italy
| | - P. Vici
- Division of Medical Oncology B, Regina Elena National Cancer Institute, Rome; Departments of
| | - D. Serpico
- Department of Medical Oncology and Endocrinology, Federico II Medical School of Naples, Naples
| | - A. Giordano
- Sbarro Institute for Cancer Research and Molecular Medicine, Center for Biotechnology, Temple University, Philadelphia, USA
- Human Health Foundation, Spoleto-Terni
| | | | - A. Crispo
- Epidemiology, G. Pascale National Cancer Institute, Naples
| | - M. Montella
- Epidemiology, G. Pascale National Cancer Institute, Naples
| | - G. Capurso
- Digestive and Liver Disease Unit, II Medical School, University La Sapienza, Rome
| | - G. Delle Fave
- Digestive and Liver Disease Unit, II Medical School, University La Sapienza, Rome
| | - B. Fuhrman
- Department of Epidemiology, Regina Elena National Cancer Institute, Rome, Italy
| | - C. Botti
- Department of Surgery, Regina Elena National Cancer Institute, Rome, Italy
| | - S. De Placido
- Department of Medical Oncology and Endocrinology, Federico II Medical School of Naples, Naples
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Phosphorylated Insulin Like Growth Factor-I Receptor Expression and Its Clinico-Pathological Significance in Histologic Subtypes of Human Thyroid Cancer. Exp Biol Med (Maywood) 2009; 234:372-86. [DOI: 10.3181/0809-rm-284] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Overexpression of insulin-like growth factor-I receptor (IGF-IR) is seen in a multitude of human thyroid cancers and correlates with poor prognosis. However, recent studies suggest that low phospho-IGF-IR (pIGF-IR) expression rather than its overexpression may be an indicator of poorly differentiated disease. No previous study has evaluated the expression of pIGF-IR to determine if activation or loss of expression of this receptor is associated with thyroid tumor progression. Accordingly, a quantitative immunohistochemical (IHC) method was used to evaluate the clinico-pathological significance of pIGF-IR expression in archival samples of human thyroid carcinomas. Quantitative analysis of pIGF-IR levels revealed a significant difference in the median index of pIGF-IR between different histological subtypes of thyroid cancer ( P < 0.001). Specifically, the median pIGF-IR index of differentiated thyroid cancers was significantly higher than the median index of other poorly differentiated thyroid cancer ( P < 0.001). This was further confirmed in individual tumor sections of thyroid carcinoma where anaplastic and differentiated components co-existed. No significant difference was noted in the pIGF-IR index of tumors grouped by size or stage but a trend towards lower mean pIGF-IR index was noted in older patients. Our data indicates that pIGF-IR is upregulated in a majority of follicular thyroid carcinomas, suggesting it may be a potential target for therapy for patients with this disease. In addition, since low pIGF-IR expression was found to correlate with aggressive human thyroid carcinoma, it also suggests that IGF-IR may not be needed for progression of anaplastic thyroid carcinoma possibly because other cell signaling pathways are activated, obviating the need for IGF-IR signaling. However, more mechanistic studies would be necessary to substantiate the possibility that pIGF-IR may be important for differentiation of thyroid tissues and is lost with disease progression.
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Daniel CR, Bostick RM, Flanders WD, Long Q, Fedirko V, Sidelnikov E, Seabrook ME. TGF-alpha expression as a potential biomarker of risk within the normal-appearing colorectal mucosa of patients with and without incident sporadic adenoma. Cancer Epidemiol Biomarkers Prev 2009; 18:65-73. [PMID: 19124482 DOI: 10.1158/1055-9965.epi-08-0732] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Transforming growth factor-alpha (TGF-alpha), a stimulatory growth factor and member of the epidermal growth factor family, is a mediator of oncogenesis and malignant progression in colorectal carcinogenesis. Limited evidence suggests its utility as a growth-related biomarker of risk for colorectal cancer. METHODS We measured expression of TGF-alpha in biopsies of normal-appearing colorectal mucosa using automated immunohistochemistry and quantitative image analysis in a subsample of 29 cases and 31 controls from a colonoscopy-based case-control study (n = 203) of biomarkers of risk for incident sporadic colorectal adenoma. Diet, lifestyle, and medical history were assessed with validated questionnaires. RESULTS TGF-alpha expression in the rectum was 51% higher in cases compared with controls (P = 0.05) and statistically significantly associated with accepted risk factors for colorectal neoplasms (36% lower among nonsteroidal anti-inflammatory drug users, 49% lower among women using hormone replacement therapy, 79% higher among persons with a family history of colorectal cancer). CONCLUSIONS TGF-alpha expression in the normal-appearing rectal mucosa shows promise as an early, potentially modifiable biomarker of risk for colorectal cancer.
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Affiliation(s)
- Carrie R Daniel
- Nutrition and Health Sciences Program, Graduate Division of Biological and Biomedical Sciences, Emory University, Atlanta, Georgia 30322, USA
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Jin Q, Esteva FJ. Cross-talk between the ErbB/HER family and the type I insulin-like growth factor receptor signaling pathway in breast cancer. J Mammary Gland Biol Neoplasia 2008; 13:485-98. [PMID: 19034632 DOI: 10.1007/s10911-008-9107-3] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/13/2008] [Accepted: 11/13/2008] [Indexed: 12/15/2022] Open
Abstract
Understanding the molecular mechanisms involved in tumorigenesis and their influence on clinical outcome is providing specific molecular markers for targeted therapy. Activation of tyrosine kinase receptors from the human epidermal growth factor receptor family (EGFR, HER2, HER3, HER4) and the insulin-like growth factor receptor I (IGF-IR) plays a key role in the initiation and progression of breast cancer. HER2 overexpression is a validated therapeutic target, as shown by the clinical efficacy of trastuzumab and lapatinib. However, only 25-30% of patients with HER2-overexpressing tumors respond to single-agent trastuzumab or lapatinib, and resistance develops even in responding patients. Therefore, to optimize therapeutic efficacy, it is urgent to elucidate the complex network of signaling pathways that develop in breast cancer cells. Signaling interactions have been reported between ErbB/HER family members and IGF-IR. As increased IGF-IR signaling has been implicated in trastuzumab resistance, agents targeting HER2, and IGF-IR could be potential therapeutic tools in breast cancers that develop resistance to HER2-directed therapy.
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Affiliation(s)
- Quanri Jin
- Departments of Breast Medical Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, TX, USA
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Hu YP, Patil SB, Panasiewicz M, Li W, Hauser J, Humphrey LE, Brattain MG. Heterogeneity of receptor function in colon carcinoma cells determined by cross-talk between type I insulin-like growth factor receptor and epidermal growth factor receptor. Cancer Res 2008; 68:8004-13. [PMID: 18829558 DOI: 10.1158/0008-5472.can-08-0280] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study identifies a novel cross-talk paradigm between the type I insulin-like growth factor receptor (IGF1R) and epidermal growth factor receptor (EGFR) in colon cancer cells. IGF1R activation by ligand exposure in growth factor-deprived cells induces Akt activation in the FET, CBS, and GEO colon cancer cell lines. Investigation of IGF1R-mediated signaling pathways using small interfering RNA approaches indicated that, as expected, phosphatidylinositol 3'-kinase (PI3K) was activated by IGF1R. Mitogen-activated protein kinase (MAPK) activity as reflected by phospho-extracellular signal-regulated kinase (ERK) induction was not significantly activated until later times following release of these cells from growth factor deprivation stress. The appearance of phospho-ERK was proximal to EGFR activation. Treatment of cells with the PI3K inhibitor LY294002 before release from stress resulted in a concentration-dependent loss of EGFR activation, whereas treatment with the MAPK inhibitor PD98059 did not block EGFR activation, indicating that EGFR activation was downstream of the IGF1R/PI3K pathway. PD98059 inhibition of MAPK was associated with a concentration-dependent reduction in EGFR-mediated phospho-ERK. EGFR inhibitor blocked induction of phospho-ERK, showing that MAPK activity was a consequence of EGFR-mediated signaling. On the other hand, a small-molecule IGF1R inhibitor, PQIP, blocked Akt phosphorylation. The divergent signaling functions of IGF1R and EGFR suggested the potential for synergism by a combination of therapy directed at the two receptors. Combination treatment with PQIP and EGFR inhibitor Tarceva resulted in synergistic effects as indicated by combination index analysis in all three cell lines tested.
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Affiliation(s)
- Yi Peter Hu
- Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198-7696, USA
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Handolias D, McArthur GA. Imatinib as effective therapy for dermatofibrosarcoma protuberans: proof of concept of the autocrine hypothesis for cancer. Future Oncol 2008; 4:211-7. [DOI: 10.2217/14796694.4.2.211] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Cancer literature has consistently described autocrine loops involving growth factors to be important mechanisms for cellular transformation and proliferation in preclinical cancer models. Finally, convincing clinical data exist to implicate autocrine loops as central to the pathogenesis of a malignant condition, largely as a result of the recent development of inhibitors of protein tyrosine kinases important in cell signaling and growth. Although a rare condition, the study of patients with dermatofibrosarcoma protuberans (DFSP) is enriched by data demonstrating strong scientific rationale for its pathogenesis and susceptibility to molecular-based therapies. DFSP is a low-grade sarcoma that responds to treatment with imatinib, an inhibitor of the PDGF receptor tyrosine kinase. This treatment response illustrates the importance of autocrine/paracrine loops involving PDGF and its receptor as the key molecular target in DFSP. New insight into this fundamental biological mechanism sets the scene for the further development of molecular-targeted therapeutic options for cancer.
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Affiliation(s)
- Despina Handolias
- Peter MacCallum Cancer Centre, Department of Haematology and Medical Oncology, Locked Bag 1, A’Beckett Street, Victoria 8006, Australia
| | - Grant A McArthur
- Peter MacCallum Cancer Centre, Department of Haematology and Medical Oncology, Locked Bag 1, A’Beckett Street, Victoria 8006, Australia
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Heo JS, Lee SH, Han HJ. Regulation of DNA synthesis in mouse embryonic stem cells by transforming growth factor-alpha: involvement of the PI3-K/Akt and Notch/Wnt signaling pathways. Growth Factors 2008; 26:104-16. [PMID: 18428029 DOI: 10.1080/08977190802066655] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
This study examined the mechanisms by which transforming growth factor (TGF)-alpha regulates proliferation of mouse embryonic stem (ES) cells. TGF-alpha increased [3H] thymidine and BrdU incorporation in a time- (0-72 h) and dose-dependent (0-10 ng/ml) manner. TGF-alpha stimulated the phosphorylation of Akt, mammalian target of rapamycin (mTOR), p70S6K1 and p44/42 mitogen-activated protein kinases (MAPKs). TGF-alpha also increased the protein levels of Notch, Notch intracellular domain, Hes-1 and Wnt1. However, TGF-alpha-induced DNA synthesis was blocked by inhibition of Akt, mTOR, p44/42 MAPKs and Notch. TGF-alpha increased the gene expression of c-jun, c-myc and c-fos. Moreover, TGF-alpha increased cyclin D/CDK 4 and cyclin E/CDK 2 levels, while decreasing p21cip1/waf1 and p27kip1, which were blocked by the inhibition of Akt, mTOR and Notch. In conclusion, TGF-alpha regulated DNA synthesis of mouse ES cells via PI3-K/Akt, p44/42 MAPKs and Notch/Wnt pathways.
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Affiliation(s)
- Jung Sun Heo
- Department of Veterinary Physiology, Biotherapy Human Resources Center (BK 21), College of Veterinary Medicine, Chonnam National University, Gwangju, South Korea
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Nicholson RI, Hutcheson IR, Jones HE, Hiscox SE, Giles M, Taylor KM, Gee JMW. Growth factor signalling in endocrine and anti-growth factor resistant breast cancer. Rev Endocr Metab Disord 2007; 8:241-53. [PMID: 17486454 DOI: 10.1007/s11154-007-9033-5] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Growth factors provide powerful mitogenic and survival signals to breast cancer cells and it is therefore not surprising that they are able to subvert inhibitory responses to anti-hormonal drugs. In this review we discuss several mechanisms by which this may be achieved and expand our observations to encompass recently emerging anti-growth factor treatments. The information presented is underpinned by inhibitor studies that show the targeting of such mechanisms in advance of anti-hormone or anti-growth factor resistance development is able to substantially delay this event, thus pointing the way forward to intelligent combination therapies relevant to the future management of breast cancer.
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Affiliation(s)
- R I Nicholson
- Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Cardiff University, Cardiff, UK.
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McCole DF, Truong A, Bunz M, Barrett KE. Consequences of Direct Versus Indirect Activation of Epidermal Growth Factor Receptor in Intestinal Epithelial Cells Are Dictated by Protein-tyrosine Phosphatase 1B. J Biol Chem 2007; 282:13303-15. [PMID: 17339316 DOI: 10.1074/jbc.m700424200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The epidermal growth factor receptor (EGFR) is an integral regulator of many cellular functions. EGFR also acts as a central conduit for extracellular signals involving direct activation of the receptor by EGFR ligands or indirect activation by G protein-coupled receptor (GPCR)-stimulated transactivation of the EGFR. We have previously shown that EGFR negatively regulates epithelial chloride secretion as a result of transforming growth factor-alpha-mediated EGFR transactivation in response to muscarinic GPCR activation. Here we show that direct activation of the EGFR by EGFR ligands produces a different pattern of EGFR tyrosine phosphorylation and downstream phosphatidylinositol 3-kinase recruitment than GPCR-stimulated transactivation of the EGFR occurring via paracrine EGFR ligand release. Moreover, we demonstrate that this differential signaling and its consequences depend on protein-tyrosine phosphatase 1B activity. Thus protein-tyrosine phosphatase 1B governs differential recruitment of signaling pathways involved in EGFR regulation of epithelial ion transport. Our findings furthermore establish how divergent signaling outcomes can arise from the activation of a single receptor.
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Affiliation(s)
- Declan F McCole
- Department of Medicine, University of California, San Diego, School of Medicine, La Jolla, California 92093, USA.
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Rajput A, Koterba AP, Kreisberg JI, Foster JM, Willson JKV, Brattain MG. A novel mechanism of resistance to epidermal growth factor receptor antagonism in vivo. Cancer Res 2007; 67:665-73. [PMID: 17234777 DOI: 10.1158/0008-5472.can-06-2773] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epidermal growth factor receptor (EGFR) is widely expressed in a number of solid tumors including colorectal cancers. Overexpression of this receptor is one means by which a cell can achieve positive signals for survival and proliferation; another effective means is by constitutive activation of EGFR. We have elucidated the role of constitutive EGFR signaling in malignant progression by stably transfecting colon cancer cells with a human transforming growth factor-alpha cDNA (a ligand for EGFR) under repressible control by tetracycline. We show that constitutive expression of transforming growth factor-alpha and its subsequent constitutive activation of EGFR allows for cancer cell survival in response to environmental stress in vitro and in vivo as well. The reversal of constitutive EGFR activation results in the loss of downstream mitogen-activated protein kinase and Akt activation, and a reduction in xenograft size that is associated with decreased proliferation and increased apoptosis. We used CI-1033, a small molecule antagonist of EGFR, to dissect an activation pathway that shows the ability of ERBb2 to activate Akt, but not Erk in the face of EGFR antagonism. This novel escape mechanism is a possible explanation of why anti-EGFR therapies have shown disappointing results in clinical trials.
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Affiliation(s)
- Ashwani Rajput
- Department of Surgical Oncology, Roswell Park Cancer Institute, The State University of New York at Buffalo, Buffalo, New York 14263, USA
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15
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Zhou Y, Li S, Hu YP, Wang J, Hauser J, Conway AN, Vinci MA, Humphrey L, Zborowska E, Willson JKV, Brattain MG. Blockade of EGFR and ErbB2 by the novel dual EGFR and ErbB2 tyrosine kinase inhibitor GW572016 sensitizes human colon carcinoma GEO cells to apoptosis. Cancer Res 2006; 66:404-11. [PMID: 16397255 DOI: 10.1158/0008-5472.can-05-2506] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Coexpression of the epidermal growth factor receptor (EGFR) family receptors is found in a subset of colon cancers, which may cooperatively promote cancer cell growth and survival, as heterodimerization is known to provide for diversification of signal transduction. Recently, efforts have been made to develop novel 4-anilinoquinazoline and pyridopyrimidine derivatives to inhibit EGFR and ErbB2 kinases simultaneously. In this study, we tested the efficacy of a novel reversible dual inhibitor GW572016 compared with the selective EGFR and ErbB2 tyrosine kinase inhibitors (TKI) AG1478 and AG879 and their combination, using the human colon adenocarcinoma GEO mode. GEO cells depend on multiple ErbB receptors for aberrant growth. A synergistic effect on inhibition of cell proliferation associated with induction of apoptosis was observed from the combination of AG1478 and AG879. Compared with AG1478 or AG879, the single TKI compound GW572016 was a more potent inhibitor of GEO cell proliferation and was able to induce apoptosis at lower concentrations. Western blot analysis revealed that AG1478 and AG879 were unable to suppress both EGFR and ErbB2 activation as well as the downstream mitogen-activated protein kinase (MAPK) and AKT pathways as single agents. In contrast, GW572016 suppressed the activation of EGFR, ErbB2, MAPK, and AKT in a concentration-dependent manner. Finally, in vivo studies showed that GW572016 treatment efficiently blocked GEO xenograft growth at a dose range of 30 to 200 mg/kg with a twice-daily schedule. In summary, our study indicates that targeting both EGFR and ErbB2 simultaneously could enhance therapy over that of single agents directed at EGFR or ErbB2 in cancers that can be identified as being primarily heterodimer-dependent.
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Affiliation(s)
- Yunfei Zhou
- Department of Pharmacology and Therapeutics, Roswell Park Cancer Institute, Buffalo, New York 14263, USA
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16
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Jones HE, Gee JM, Hutcheson IR, Nicholson RI. Insulin-like growth factor-I receptor signaling and resistance in breast cancer. Expert Rev Endocrinol Metab 2006; 1:33-46. [PMID: 30743767 DOI: 10.1586/17446651.1.1.33] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Insulin-like growth factor-I receptor (IGF-IR) signaling is involved in many fundamental adverse aspects of cancer cell biology, such as proliferation, cell survival and migration. Its anti-apoptotic properties have implicated the receptor in mediating decreased sensitivity to chemotherapeutic drugs and radiation treatment; however, data are emerging that also indicates a role for IGF-IR signaling in resistance, not only to antihormones but also to antigrowth factor strategies such as agents that target the erb family of receptors. As such, IGF-IR is clearly an attractive therapeutic target for the treatment of cancer, including breast cancer, where there is evidence of clinical prominence of the IGF-IR pathway and, as such, numerous strategies are currently in development to inhibit IGF-IR signaling. This review focuses on the ability of the IGF-IR to contribute to resistance mechanisms that support breast cancer cell growth in the presence of antihormones and antigrowth factors and discusses methods to maximize antitumor effects by combination regimens cotargeting the IGF-IR that may delay, or even prevent, progression to the resistant phenotype.
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Affiliation(s)
- Helen E Jones
- a Cardiff University, Tenovus Centre for Cancer Research, King Edward VII Avenue, Cardiff CF10 3XF, UK.
| | - Julia Mw Gee
- a Cardiff University, Tenovus Centre for Cancer Research, King Edward VII Avenue, Cardiff CF10 3XF, UK.
| | - Iain R Hutcheson
- a Cardiff University, Tenovus Centre for Cancer Research, King Edward VII Avenue, Cardiff CF10 3XF, UK.
| | - Robert I Nicholson
- a Cardiff University, Tenovus Centre for Cancer Research, King Edward VII Avenue, Cardiff CF10 3XF, UK.
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17
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Knowlden JM, Hutcheson IR, Barrow D, Gee JMW, Nicholson RI. Insulin-like growth factor-I receptor signaling in tamoxifen-resistant breast cancer: a supporting role to the epidermal growth factor receptor. Endocrinology 2005; 146:4609-18. [PMID: 16037379 DOI: 10.1210/en.2005-0247] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
There is considerable evidence that the epidermal growth factor receptor (EGFR) and IGF-I receptor (IGF-IR) cross-talk in breast cancer cells. In the present study, we have examined whether EGFR/IGF-IR cross-talk exists in EGFR-positive tamoxifen-resistant variants of MCF-7 (Tam-R) and T47D (T47D-R) breast cancer cell lines. Although Tam-R cells expressed reduced IGF-IR protein levels compared with their wild-type MCF-7 counterparts, phosphorylated IGF-IR protein levels were equivalent in the two cell lines under basal growth conditions, possibly as a consequence of increased IGF-II expression in Tam-R cells. IGF-II activated both IGF-IR and EGFR in Tam-R cells, whereas only activation of IGF-IR was observed in wild-type cells. In contrast, epidermal growth factor rapidly induced EGFR, but not IGF-IR, phosphorylation in Tam-R cells. IGF-II promoted direct association of c-SRC with IGF-IR, phosphorylated c-SRC, and increased EGFR phosphorylation at tyrosine 845, a c-SRC-dependent phosphorylation site. Pretreatment with either AG1024 (IGF-IR-specific inhibitor) or an IGF-II neutralizing antibody inhibited basal IGF-IR, c-SRC, and EGFR phosphorylation, and AG1024 significantly reduced Tam-R basal cell growth. The c-SRC inhibitor SU6656 also inhibited growth, reduced basal and IGF-II-induced c-SRC and EGFR phosphorylation, and blocked EGFR activation by TGFalpha. Similarly, in T47D-R cells, AG1024 and SU6656 inhibited basal and IGF-II-induced phosphorylation of c-SRC and EGFR, and SU6656 reduced TGFalpha-induced EGFR activity. These results suggest the existence of a unidirectional IGF-IR/EGFR cross-talk mechanism whereby IGF-II, acting through the IGF-IR, regulates basal and ligand-activated EGFR signaling and cell proliferation in a c-SRC-dependent manner in Tam-R cells. This cross-talk between IGF-IR and EGFR is not unique to Tam-R cells because this mechanism is also active in a tamoxifen-resistant T47D-R cell line.
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Affiliation(s)
- J M Knowlden
- Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Cardiff University, Redwood Building, King Edward VII Avenue, Cardiff CF10 3XF, United Kingdom
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18
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Durai R, Yang W, Gupta S, Seifalian AM, Winslet MC. The role of the insulin-like growth factor system in colorectal cancer: review of current knowledge. Int J Colorectal Dis 2005; 20:203-20. [PMID: 15650828 DOI: 10.1007/s00384-004-0675-4] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/23/2004] [Indexed: 02/04/2023]
Abstract
BACKGROUND The insulin-like growth factor system, which includes insulin-like growth factors (IGF-I and IGF-II), IGF receptors (IGF-IR and IGF-IIR) and IGF binding proteins (IGFBPs), plays an important role in epithelial growth, anti-apoptosis and mitogenesis. There is a growing body of evidence showing that IGFs control growth and proliferation of several types of cancer. This review introduces the latest information on the biology of the IGF system and its pathophysiological role in the development of colorectal cancer. DISCUSSION The growth promoting effects of IGF-I and IGF-II on cancer cells are mediated through the IGF-IR, which is a tyrosine kinase and cancer cells with a strong tendency to metastasise have a higher expression of the IGF-IR. Most of the IGFs in circulation are bound to the IGFBPs, which regulate the bioavailability of the IGFs. All IGFBPs inhibit IGF action by high affinity binding, while some of them also potentiate the effects of IGFs. Colon cancer cells produce specific proteases that degrade the IGFBP so that the IGF will be free to act on the cancer cell in an autocrine manner. Therefore, the IGFBPs play a crucial role in the development of the cancer. CONCLUSION The current knowledge about the link between IGFs and colon cancer is mainly based on in vitro investigations. Further in vivo study is needed to understand the exact role of the IGF system, especially its binding proteins, so that they can be manipulated for the prevention and treatment of colorectal cancer.
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Affiliation(s)
- Rajaraman Durai
- University Department of Surgery, Royal Free and University College Medical School, University College London, Rowland Hill Street, London, NW3 2PF, UK
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19
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Gali-Muhtasib HU, Diab-Assaf M, Haddadin MJ. RETRACTED ARTICLE: Quinoxaline 1,4-dioxides induce G2/M cell cycle arrest and apoptosis in human colon cancer cells. Cancer Chemother Pharmacol 2004; 55:369-378. [PMID: 15538569 DOI: 10.1007/s00280-004-0907-x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2004] [Accepted: 07/30/2004] [Indexed: 10/26/2022]
Abstract
We have recently shown that quinoxaline 1,4-dioxide (QdNO) derivatives, namely 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide (DCQ), 2-benzoyl-3-phenyl-quinoxaline 1,4-dioxide (BPQ) and 2-acetyl-3-methyl-quinoxaline 1,4-dioxide (AMQ), suppress the growth of T-84 human colon cancer cells. Here we show that the growth-suppressive effects of QdNOs are due to their ability to induce cell cycle arrest and/or apoptosis. While AMQ blocked more than 60% of cells at the G2/M phase without inducing apoptosis, DCQ caused a significant increase in apoptotic cells with no noticeable effects on the cycling of cells. Treatment with BPQ resulted in G2/M cell cycle arrest and induction of apoptosis. With regard to the effects of QdNOs on molecules that regulate apoptosis and the G2 to M transition, both BPQ and AMQ inhibited the expression of cyclin B, while DCQ significantly decreased the levels of Bcl-2 and increased Bax expression. Next, we investigated whether transforming growth factor-beta1 (TGF-beta1) and/or extracellular signal-regulated kinase (ERK) mediate the antiproliferative and apoptotic effects of QdNOs in colon cancer cells. Interestingly, the above QdNOs increased differentially total TGF beta1 mRNA expression and decreased TGF alpha mRNA and ERK phosphorylation. None of these QdNOs induced changes in TGF beta-2 mRNA expression. The addition of a specific inhibitor of MEK greatly enhanced apoptosis in cells treated with DCQ, suggesting that the inhibition of ERK phosphorylation may explain, to an extent, the apoptogenic effects of this compound. Taken together, these findings provide insights into possible molecular mechanisms of growth inhibition by QdNOs that could aid in their evaluation for anticancer therapy.
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Affiliation(s)
| | - Mona Diab-Assaf
- Department of Biology, American University of Beirut, Beirut, Lebanon
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20
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Harakeh S, Diab-Assef M, El-Sabban M, Haddadin M, Gali-Muhtasib H. Inhibition of proliferation and induction of apoptosis by 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline 1,4-dioxide in adult T-cell leukemia cells. Chem Biol Interact 2004; 148:101-13. [PMID: 15276867 DOI: 10.1016/j.cbi.2004.05.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2003] [Revised: 05/07/2004] [Accepted: 05/19/2004] [Indexed: 11/15/2022]
Abstract
Human T-cell lymphotrophic virus type-1 (HTLV-1) is a retrovirus which causes adult T-cell leukemia (ATL), an aggressive malignancy of activated T-cells. So far, there is no proven therapy for this disease. The compound 2-benzoyl-3-phenyl-6,7-dichloro quinoxaline 1,4-dioxide (DCQ) has been shown to exhibit a wide range of antibacterial activities and to induce antiproliferation and apoptosis of human colon cancer cell lines. In the present study, we investigated the in vitro effects of DCQ in HTLV-1 positive (C91-PL and HuT-102) and negative (CEM and Jurkat) malignant T-cells. The results indicate that DCQ induced growth inhibition in all four cell lines examined in a dose-dependent manner. The inhibitory effect was mainly due to the induction of apoptosis which was verified by flow cytometry analyses and ELISA-based apoptosis assays. The role of transforming growth factor (TGF) in mediating the antiproliferative and apoptotic effects of DCQ in ATL cells was investigated. Interestingly, in three of the four cell lines used, DCQ increased the TGF-beta1 transcript levels and decreased TGF-alpha mRNA, but did not induce changes in TGF-beta2 expression. DCQ treatment also induced an upregulation of p53 and p21 protein levels, key mediators of cell cycle arrest and apoptosis. The anti-apoptotic Bcl-2alpha protein level was found to be reduced. These findings indicate that DCQ inhibits the growth of ATL cell lines, at least in part, by inducing apoptosis mediated by the modulation of TGF expression, the upregulation in p53 and p21 proteins and downregulation in Bcl-2alpha expression. The present findings suggest that DCQ merits further investigation as a potential therapeutic agent for this incurable disease.
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Affiliation(s)
- Steve Harakeh
- Biology Department, American University of Beirut, Lebanon.
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21
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Nicholson RI, Hutcheson IR, Knowlden JM, Jones HE, Harper ME, Jordan N, Hiscox SE, Barrow D, Gee JMW. Nonendocrine Pathways and Endocrine Resistance. Clin Cancer Res 2004; 10:346S-54S. [PMID: 14734490 DOI: 10.1158/1078-0432.ccr-031206] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Abstract
An increasing body of evidence demonstrates that growth factor networks are highly interactive with estrogen receptor signaling in the control of breast cancer growth. As such, tumor responses to antiestrogens are likely to be a composite of the estrogen receptor and growth factor-inhibitory activity of these agents, with alterations/aberrations in growth factor signaling providing a mechanism for the development of antiestrogen resistance. In this light, the current article focuses on illustrating the relationship between growth factor signaling and antiestrogen failure in our in-house tumor models of breast cancer and describing how we are now beginning to successfully target growth factor activity to improve the effects of antiestrogen drugs and to block aggressive disease progression.
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Affiliation(s)
- Robert I Nicholson
- Tenovus Centre for Cancer Research, Welsh School of Pharmacy, Cardiff, Wales, United Kingdom.
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22
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Anderson MR, Jankowski JAZ. The role of receptor tyrosine kinase inhibition in treating gastrointestinal malignancy. Expert Opin Investig Drugs 2003; 12:577-92. [PMID: 12665414 DOI: 10.1517/13543784.12.4.577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Tyrosine kinase receptors are proteins that transduce the signal from many growth factor and cytokine ligands to produce intracellular responses. As such they can activate multiple signalling cascade pathways and influence cell division, migration and survival. Many show upregulation in certain malignancies, including those of the gastrointestinal tract, and are thought to play key roles in carcinogenesis. This makes them attractive targets for drug therapy and in recent years many inhibitors have been developed. This review discusses the current situation regarding the development of inhibitors with particular reference to the erbB family, the insulin-like growth factor receptor, the Met receptor, the receptor for vascular endothelial growth factor and the Kit receptor. The evidence will be related back to cancers of the gut lumen. Clinical effectiveness in this area seems to lie in using a combinatorial approach that inhibits multiple key signalling points, and the reasons for this will be discussed.
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Affiliation(s)
- M R Anderson
- Department of Medical Sciences, University of Birmingham, Vincent Drive, Edgbaston, Birmingham, B15 2TH, UK.
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