Abstract
Background: Angiogenesis, the growth of new blood vessels, plays an important role in tumor growth and metastasis. Both cetuximab and endostatin have been found to reduce the expression of endothelial-stimulating growth factors such as vascular endothelial growth factor (VEGF) and interleukin (IL)-8. However, the effects of cetuximab alone or in combination with endostatin on human lung adenocarcinoma cell growth remain unclear.
Objective: The aim of this study was to evaluate the cellular and molecular effects of cetuximab alone and in combination with endostatin on human lung adenocarcinoma cell lines HI 299, SPC-A1, and H460 in vitro.
Methods The epidermal growth factor receptor (EGFR) status of a panel of human lung adenocarcinoma cell lines was characterized using Western blot analysis. We used a modified tetrazolium salt assay to evaluate the growth-inhibitory effects of cetuximab and endostatin alone and in combination on the cell lines. We also determined the effects of these 2 drugs on VEGF and IL-8 expression using enzyme-linked immunosorbent assay (ELISA) and Western blot analysis. Cells were treated for 4 days with cetuximab 12.5 μ/mL, endostatin 25 μ/mL, or cetuximab 12.5 μg/mL + endostatin 25 μg/mL. Untreated cells cultured for 4 days served as controls.
Results: EGFR expression in the H1299 cells was higher than in the SPC-A1 and H460 cells. Varying concentrations of cetuximab alone were associated with a significant growth-inhibitory effect on all 3 cell lines in a dose-dependent manner after 4 days of exposure compared with controls (all, P < 0.05). Compared with controls, varying concentrations of endostatin alone were not associated with significant inhibition of cell growth in any of the 3 cell lines. The inhibitory ratio of cetuximab + endostatin at varying concentrations was significantly greater than that of cetuximab alone (all, P < 0.05). On ELISA, either drug alone was associated with significant reductions in secreted VEGF and IL-8 in the HI 299, SPC-A1, and H460 cell lines (all, P < 0.05), with the exception of IL-8 concentration in the H460 cells. Mean (SD) VEGF expression with combination treatment in the H1299 and SPC-A1 cell lines (687 [21] and 629 [23] pg/mL, respectively) was significantly lower than with cetuxi-mab alone (878 [31] and 708 [20] pg/mL; both, P < 0.001); in the H460 cell line, combination treatment was not associated with a significant further reduction in VEGF expression. IL-8 concentrations with cetuximab in the H1299, SPC-A1, and H460 cell lines were 628 (20), 484 (29), and 532 (28) pg/mL, respectively, while the IL-8 concentrations with the combination treatment were 516 (20), 480 (18), and 467 (30) pg/mL. An enhanced effect of endostatin on IL-8 was observed in the H1299 and H460 cell lines (P < 0.001 and P = 0.018, respectively); however, no enhanced effect in the SPC-A1 line was observed. Similar results for VEGF and IL-8 expression were found using Western blot analysis.
Conclusions: The results from this in vitro study suggest that cetuximab treatment might both inhibit human lung adenocarcinoma cell line growth and reduce the expression of VEGF and IL-8, which are the biomarkers of angiogenesis. Endostatin was not associated with inhibition of human lung adenocarcinoma cell line growth directly. Findings with the combination of cetuximab + endostatin suggest that endostatin might enhance the antiangiogenic and antitumor activity of cetuximab through an apparent effect on VEGF expression and, to a lesser degree, on IL-8 expression.
Key words: cetuximab, endostatin, angiogenesis, lung neoplasms
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References
- 1.Folkman J. Tumor angiogenesis and tissue factor. Nat Med. 1996;2:167–168. doi: 10.1038/nm0296-167. [DOI] [PubMed] [Google Scholar]
- 2.Salomon DS, Brandt R, Ciardiello F, Normanno N. Epidermal growth factor-related peptides and their receptors in human malignancies. Crit Rev Oncol Hematol. 1995;19:183–232. doi: 10.1016/1040-8428(94)00144-i. [DOI] [PubMed] [Google Scholar]
- 3.Rusch V, Klimstra D, Venkatraman E. Over expression of the epidermal growth factor receptor and its ligand transforming growth factor alpha is frequent in resectable non-small cell lung cancer but does not predict tumor progression. Clin Cancer Res. 1997;3:515–522. [PubMed] [Google Scholar]
- 4.Fontanini G, De Laurentiis M, Vignati S. Evaluation of epidermal growth factor-related growth factors and receptors and of neoangiogenesis in completely resected stage I–IIIA non-small cell lung cancer: Amphiregulin and microvessel count are independent prognostic indicators of survival. Clin Cancer Res. 1998;4:241–249. [PubMed] [Google Scholar]
- 5.Fox SB, Smith K, Hollyer J. The epidermal growth factor receptor as a prognostic marker: Results of 370 patients and review of 3009 patients. Breast Cancer Res Treat. 1994;29:41–49. doi: 10.1007/BF00666180. [DOI] [PubMed] [Google Scholar]
- 6.Petit AM, Rak J, Hung MC. Neutralizing antibodies against epidermal growth factor and ErbB-2/neu receptor tyrosine kinases down-regulate vascular endothelial growth factor production by tumor cells in vitro and in vivo: Angiogenic implications for signal transduction therapy of solid tumors. Am J Pathol. 1997;151:1523–1530. [PMC free article] [PubMed] [Google Scholar]
- 7.Dinney CP, Parker C, Dong Z. Therapy of human transitional cell carcinoma of the bladder by oral administration of epidermal growth factor receptor protein tyrosine kinase inhibitor 4,5-dianilinophthalimide. Clin Cancer Res. 1997;3:161–168. [PubMed] [Google Scholar]
- 8.Rak J, Kerbel RS. Treating cancer by inhibiting angiogenesis: New hopes and potential pitfalls. Cancer Metastasis Rev. 1996;15:231–236. doi: 10.1007/BF00437476. [DOI] [PubMed] [Google Scholar]
- 9.Vanhoefer U. Molecular mechanisms and targeting of colorectal cancer. Semin Oncol. 2005;32(Suppl 8):7–10. doi: 10.1053/j.seminoncol.2005.07.018. [DOI] [PubMed] [Google Scholar]
- 10.O’Reilly MS, Boehm T, Shing Y. Endostatin: An endogenous inhibitor of angiogenesis and tumor growth. Cell. 1997;88:277–285. doi: 10.1016/s0092-8674(00)81848-6. [DOI] [PubMed] [Google Scholar]
- 11.Boehm T, Folkman J, Browder T, O’Reilly MS. Antiangiogenic therapy of experimental cancer does not induce acquired drug resistance. Nature. 1997;390:404–407. doi: 10.1038/37126. [DOI] [PubMed] [Google Scholar]
- 12.Oh SP, Kamagata Y, Muragaki Y. Isolation and sequencing of cDNAs for proteins with multiple domains of Gly-Xaa-Yaa repeats identify a distinct family of collagenous proteins. Proc Natl Acad Sci U S A. 1994;91:4229–4233. doi: 10.1073/pnas.91.10.4229. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.O’Reilly MS, Holmgren L, Shing Y. Angiostatin: A novel angiogenesis inhibitor that mediates the suppression of metastases by a Lewis lung carcinoma. Cell. 1994;79:315–328. doi: 10.1016/0092-8674(94)90200-3. [DOI] [PubMed] [Google Scholar]
- 14.Claesson-Welsh L, Welsh M, Ito N. Angiostatin induces endothelial cell apoptosis and activation of focal adhesion kinase independently of the integr in-binding motif RGD. Proc Natl Acad Sci U S A. 1998;95:5579–5583. doi: 10.1073/pnas.95.10.5579. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Yamaguchi N, Anand-Apte B, Lee M. Endostatin inhibits VEGF-induced endothelial cell migration and tumor growth independently of zinc binding. EMBO J. 1999;18:4414–4423. doi: 10.1093/emboj/18.16.4414. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Carmichael J, Mitchell JB, DeGraff WG. Chemosensitivity testing of human lung cancer cell lines using the MTT assay. Br J Cancer. 1988;57:540–547. doi: 10.1038/bjc.1988.125. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Yen L, You XL, Moustafa AE. Heregulin selectively upregulates vascular endothelial growth factor secretion in cancer cells and stimulates angiogenesis. Oncogene. 2000;19:3460–3469. doi: 10.1038/sj.onc.1203685. [DOI] [PubMed] [Google Scholar]
- 18.Luca M, Huang S, Gershenwald JE. Expression of interleukin-8 by human melanoma cells up-regulates MMP-2 activity and increases tumor growth and metastasis. Am J Pathol. 1997;151:1105–1113. [PMC free article] [PubMed] [Google Scholar]
- 19.Miller LJ, Kurtzman SH, Wang Y. Expression of interleukin-8 receptors on tumor cells and vascular endothelial cells in human breast cancer tissue. Anticancer Res. 1998;18:77–81. [PubMed] [Google Scholar]
- 20.Herbst RS, Fidler IJ. Angiogenesis and lung cancer: Potential for therapy. Clin Cancer Res. 2000;6:4604–4606. [PubMed] [Google Scholar]
- 21.Behrens C, Lin HY, Lee JJ. Immunohistochemical expression of basic fibroblast growth factor and fibroblast growth factor receptors 1 and 2 in the pathogenesis of lung cancer. Clin Cancer Res. 2008;14:6014–6022. doi: 10.1158/1078-0432.CCR-08-0167. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Westphal JR, Van’t Hullenaar R, Peek R. Angiogenic balance in human melanoma: Expression of VEGF, bFGF, IL-8, PDGF and angiostatin in relation to vascular density of xenografts in vivo. Int J Cancer. 2000;86:768–776. doi: 10.1002/(sici)1097-0215(20000615)86:6<768::aid-ijc3>3.0.co;2-e. [DOI] [PubMed] [Google Scholar]
- 23.Nissen LJ, Cao R, Hedlund EM. Angiogenic factors FGF2 and PDGF-BB synergistical-ly promote murine tumor neovascularization and metastasis. J Clin Invest. 2007;117:2766–2777. doi: 10.1172/JCI32479. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Ciardiello F, Tortora G. A novel approach in the treatment of cancer: Targeting the epidermal growth factor receptor. Clin Cancer Res. 2001;7:2958–2970. [PubMed] [Google Scholar]
- 25.Herbst RS, Langer CJ. Epidermal growth factor receptors as a target for cancer treatment: The emerging role of IMC-C225 in the treatment of lung and head and neck cancers. Semin Oncol. 2002;29(Suppl 4):27–36. doi: 10.1053/sonc.2002.31525. [DOI] [PubMed] [Google Scholar]
- 26.Mendelsohn J. Epidermal growth factor receptor inhibition by a monoclonal antibody as anticancer therapy. Clin Cancer Res. 1997;3:2703–2707. [PubMed] [Google Scholar]
- 27.Mendelsohn J. Blockade of receptors for growth factors: An anticancer therapy—the fourth annual Joseph H Burchenal American Association of Cancer Research Clinical Research Award Lecture. Clin Cancer Res. 2000;6:747–753. [PubMed] [Google Scholar]
- 28.Perletti G, Concari P, Giardini R. Antitumor activity of endostatin against carcinogen-induced rat primary mammary tumors. Cancer Res. 2000;60:1793–1796. [PubMed] [Google Scholar]
- 29.Yokoyama Y, Green JE, Sukhatme VP, Ramakrishnan S. Effect of endostatin on spontaneous tumorigenesis of mammary adenocarcinoma in a transgenic mouse model. Cancer Res. 2000;60:4362–4365. [PubMed] [Google Scholar]
- 30.Dhanabal M, Ramchandran R, Volk R. Endostatin: Yeast production, mutants, and antitumor effect in renal cell carcinoma. Cancer Res. 1999;59:189–197. [PubMed] [Google Scholar]
- 31.Fontanini G, Faviana P, Lucchi M. A high vascular count and over expression of vascular endothelial growth factor are associated with unfavourable prognosis in operated small cell lung carcinoma. Br J Cancer. 2002;86:558–563. doi: 10.1038/sj.bjc.6600130. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 32.Haraguchi M, Komuta K, Akashi A. Elevated IL-8 levels in the drainage vein of resectable Dukes’ C colorectal cancer indicate high risk for developing hepatic metastasis. Oncol Rep. 2002;9:159–165. [PubMed] [Google Scholar]
- 33.Li A, Dubey S, Varney ML. IL-8 directly enhanced endothelial cell survival, proliferation, and matrix metalloproteinases production and regulated angiogenesis. J Immunol. 2003;170:3369–3376. doi: 10.4049/jimmunol.170.6.3369. [DOI] [PubMed] [Google Scholar]
- 34.Heidemann J, Ogawa H, Dwinell B. Angiogenic effects of interleukin 8 (CXCL8) in human intestinal microvascular endothelial cells are mediated by CXCR2. J Biol Chem. 2003;278:8508–8515. doi: 10.1074/jbc.M208231200. [DOI] [PubMed] [Google Scholar]
- 35.Chen JJ, Yao PL, Yuan A. Up-regulation of tumor interleukin-8 expression by infiltrating macrophages: Its correlation with tumor angiogenesis and patient survival in non-small cell lung cancer. Clin Cancer Res. 2003;9:729–737. [PubMed] [Google Scholar]
