All-trans Retinoid Acid Derivatives Affects The Biological Behavior Of Hypopharyngeal Cancer Cell Via Myosin Light Chain Kinase

Aim To investigates whether MLCK can be used as a potential target for hypopharyngeal carcinoma,explore its mechanism and find potential therapeutic drugs,and provide a theoretical basis for its clinical application.Methods Clinical biophsy(108 cases)of hypopharyngeal carcinoma were collected,Immunohistochemical was performed to detect the expression of MLCK,Cox-2,E-Cad,Graphpad Prism 6 statistically was used to analyze the relationship between MLCK expression and clinical score.MTT,flow cytometry,transwell,TUNEL and ISOL were used to detect the effects of ATPR on cell proliferation,migration and apoptosis.The sh RNA was transfected to knock down the expression of MLCK in FaDu cells to explore the effect of MLCK on cell migration.The liposome transfection method was performed to establish over-expressing MLCK cell line to explore the effects of MLCK on cell migration,proliferation and apoptosis,and the effect of MLCK on ATPR-induced cell proliferation,apoptosis and migration.FaDu cells were subcutaneously transplanted into nude mice,and were treated with ATPR to explore its effect on the growth of transplanted tumors in nude mice.Results The expression of MLCK in hypopharyngeal carcinoma tissues was significantly increased compared with adjacent normal tissue,and its expression is negatively correlated with the five-year survival rate,suggesting its possibility as a potential therapeutic target.MLCK knockdown significantly inhibited the migration of FaDu cells.Meantime,ATPR can inhibit the expression and activity of MLCK,inhibit the proliferation and migration of FaDu cells,and induce FaDu cell apoptosis.At the same time,the results of in vivo experiments confirmed that ATPR can inhibit the tumorigenic ability of FaDu in nude mice,and has no obvious toxicity to other tissues of nude mice.In order to explore whether the effects of ATPR was associated with MLCK,we established the MLCK overexpression FaDu cells.Overexpression of MLCK significantly increased the migration and apoptosis of FaDu cells and attenuated the inhibition of cell migration induced by ATPR,suggesting that ATPR's inhibition of FaDu cell migration is related to MLCK expression and activity.However,the overexpression of MLCK did not affect the proliferation inhibitory effect of ATPR on FaDu cells.It suggests that there are other mechanisms involved in the regulation of ATPR's tumor suppressor effect.Interestingly,overexpression of MLCK increases the sensitivity of cells to apoptosis induction.It is suggested that MLCK is involved in tumor suppression induced by ATPR,and its regulatory mechanism is relatively complicated.Conclusions The expression of MLCK is closely related to tumor cell migration,invasion and 5-year survival rate.ATPR inhibits tumor cell migration in vivo and in vitro by inhibiting the expression and activity of MLCK.MLCK did not affect proliferation inhibition induced by ATPR.Overexpression of MLCK significantly increases the apoptosis of tumor cells induced by ATPR.The data suggest that MLCK could be target for cancer cells metastasis.