Radio-sensitizing effect of ethyl caffeate on nasopharyngeal carcinoma CNE-2 cell line
Purpose: To investigate the radio-sensitizing effect of ethyl caffeate (ETF) on naso-pharyngeal carcinoma.
Methods: MTT (3-(4, 5-dimethylthiazolyl-2)-2, 5-diphenyltetrazolium bromide) assay was used to evaluate the cell viability of CNE-2 cells, while their levels of caspase-3 and caspase-9 were determined by enzyme-linked immunosorbent assay (ELISA). In addition, a xenograft model was established in nude mice. The model was treated with ETF (40 mg/kg) and subjected to β-irradiation (10 Gy) for 28 days, during which tumor volume was determined at 4-day intervals. Expressions of caspase-3, caspase-9 and Bcl-2 were determined by western blotting assay.
Results: β-irradiation (10 Gy) did not produce any obvious inhibitory effect on the proliferation of CNE-2 cells. However, ETF (10, 20 and 40 μg/mL) significantly enhanced the radiosensitivity of the cells to β- irradiation (p < 0.01) and significantly increased their levels of caspase-3 and caspase-9 (p < 0.01). The combination of ETF (40 mg/kg) with β-irradiation resulted in significant inhibition of tumor growth in mice xenograft model (p < 0.01). The combined treatment also resulted in significant up-regulation of expressions of caspase-3 and casepase-9 and significant down-regulation of Bcl-2 in the tumor tissues when compared with corresponding tissues from the control mice (p < 0.01).
Conclusion: ETF significantly enhances the sensitivity of naso-pharyngeal carcinoma CNE-2 cells to β- irradiation, probably through induction of mitochondria-mediated apoptosis. ETF may be useful for treating naso-pharyngeal carcinoma in combination with radiation therapy.
Keywords: Ethyl caffeate, Radio-sensitizing effects, Caspase, Nasopharyngeal carcinoma, CNE-2 cell line, β-irradiation
Submission of a manuscript to this journal is a representation that the manuscript has not been published previously and is not under consideration for publication elsewhere.
All authors named in each manuscript would be required to sign a form (to be supplied by the Editor) so that they may retain their copyright in the article but to assign to us (the Publishers) and its licensees in perpetuity, in all forms, formats and media (whether known or created in the future) to (i) publish, reproduce, distribute, display and store the contribution, (ii) translate the contribution into other languages, create adaptations, reprints, include within collections and create summaries, extracts and/or abstracts of the contribution, (iii) create any other derivative works(s) based on the contribution, (iv) to exploit all subsidiary rights in the contribution, (v) the inclusion of electronic links from the contribution to third party material where-ever it may be located, and (vi) license any thrid party to do any or all of the above.