Nimesulide Suppresses The Growth And Metastasis Of Human Hypopharyngeal Carcinoma Cells

Hypopharyngeal carcinoma is one of the most common head and neck squamous cell carcinomas. Although the surgery and chemoradiation were used in hypopharyngeal carcinoma therapy, the overall survival rate is still lower than other tumors in the head and neck. Cyclooxygenase-2 (COX-2), a rate-limiting enzyme in synthesis of prostaglandins (PGs) from arachidonic acid, has been reported to be involved in the critical steps in carcinogenesis and progression. COX-2 has been found to be significantly over-expressed in various malignancies, which correlates with tumor aggressiveness and poor prognosis. Nimesulide, a COX-2 selective inhibitor, was found to have antitumor effect in certain types of human cancers. However, few studies on the antitumor effect of Nimesulide have been carried out in human hypopharyngeal carcinoma cells. Therefore, the present study was designed to investigate that whether Nimesulide can reduce the malignant potential of FaDu cells, and if so what mechanism was involved in this process.Objective In present study, we aimed to detected the effect of Nimesulide, a selective COX-2 inhibitor, on the malignant potential of human hypopharyngeal carcinoma cell line (FaDu), and investigate the potential mechanism of these phenomenon.Methods The viability of FaDu cells treated with various concentrations of Nimesulide were detected by MTT assay. Morphological changes of FaDu cells in response to Nimesulide were observed by reserved microscopy and acridine orange cytochemistry staining. To further confirm the effects of Nimesulide on proliferation of FaDu cells, we detected proliferating cells using the BrdU incorporation assay. Apoptosis was examined by flow cytometry. The ability of invasion and migration of FaDu cells was detected by Transwell Chambers. The expressions of COX-2, Bcl-2, Survivin, MMP-9 and caspase-3 at mRNA and protein levels in response to Nimesulide were then examined by RT-PCR and Western blot, respectively.Results The cell surviving rates significantly decreased in time-and concentration-dependent manners as evidenced by MTT assay (P<0.05). The proliferation of FaDu cells can be suppressed by Nimesulide. The typical morphological changes of apoptotic cells were observed. The percentage of apoptosis of FaDu cells after Nimesulide-treatment for 6 h,12 h and 24 h were 32.47±6.1%, 45.87±3.19% and 44.57±4.10%, respectively, whereas, the control was 0.48±0.42% (P<0.05). The metastatic cells were decreased by Nimesulide to about 20%. Nimesulide decreased expression of COX-2, Bcl-2, Survivin and MMP-9, whereas increased expression of Caspase-3 and Bax.Conclusion In present research, the growth of FaDu cells was suppressed by Nimesulide, which may be based on the suppression of proliferation as well as viability, and the induction of apoptosis. Nimesulide also inhibited the metastasis of FaDu cells. The potential mechanism of these phenomenon may be related to the expressions of Survivin, MMP-9, and so on. The further investigation of COX-2 and its related factors may be beneficial in the hypopharyngeal clinical chemotherapy.