| Background and ObjectiveHypopharyngeal carcinoma is the worst prognosis in head and neck cancer,and its biological behavior and characteristics:aggressive,diffuse and metastatic are very high,and in the early hypopharyngeal carcinoma is prone to submucosal spread and lymphatic metastasis.At present,the more effective treatment at home and abroad is based on radical surgery,supplemented by local radiation and systemic application of chemical therapy.However,the improvement of the overall 5-year survival rate of patients with hypopharyngeal cancer has not been significantly improved.In recent years,the role of drugs in the treatment of head and neck cancer tumors has been taken seriously,It is currently considered that chemotherapy or targeted drug therapy for advanced and recurrent,or metastatic pharyngeal cancer patients is the primary means.Chemical drugs can reduce the metastatic rate of head and neck squamous cell carcinoma,reduce tumor recurrence,metastasis,improve patient survival rate..Studying on the mechanism of chemical agents in hypopharyngeal squamous cell carcinoma will contribute to the emergence of new effective treatment.Tumor deaths occur in chemical drugs,is an anticancer drug cytotoxicity against target cells,induced tumor cell death or necrosis of the passive,on the other hand is the induction of apoptosis of tumor cells.One of the basic characteristics of malignant tumor is blocked apoptosis,decrease sensitivity and inducing factor on apoptosis.The body can not eliminate tumor cells.In recent years,more and more studies have shown that induction of apoptosis is one of the main mechanisms of chemotherapeutic drugs.Chemotherapy drugs can induce tumor cell apoptosis and achieve anti-tumor effect.Endoplasmic reticulum stress(ERS)-mediated apoptosis is a new apoptosis pathway,which plays an important role in the process of apoptosis,and has been paid more and more attention.Endoplasmic reticulum(ER)is the most common and important organelle in eukaryotic cells.It is the synthesis site of proteins,lipids and carbohydrates.Proteins are synthesized,folded,assembled and transported in the endoplasmic reticulum.Endoplasmic reticulum stress(ERS)is caused by excessive accumulation of unfolded proteins and misfolded proteins,and activation of a series of signaling pathways when the intracellular or exogenous factors are responsible for the disorder of endoplasmic reticulum physiological functions.The process of cell survival and apoptosis is activated simultaneously under endoplasmic reticulum stress,and if the endoplasmic reticulum stress continues,the apoptosis process will be initiated.Does endoplasmic reticulum stress determine cell survival or death?.In tumor cells,endoplasmic reticulum stress directly induces cell death,on the other hand,it also causes drug resistance in tumor cells.Doxorubicin is a widely used in clinical effective anti-tumor drugs.It degrades the DNA by inserting a DNA base pair and affects DNA transcription and achieves the therapeutic effect of the tumor.Doxorubicin belongs to the cycle of non-specific drugs,which have a killing effect on a variety of growth stages of tumor cells.Its anti-tumor spectrum exceeds any other type of chemotherapeutic agent.The advantages of its anti-tumor spectrum is more extensive,and the inhibition of a variety of tumors are more significant.But because of its own cytotoxic side effects,doxorubicin limits its clinical application.A large number of reports of doxorubicin can induce a variety of tumor cell apoptosis,but the role of human hypopharyngeal squamous cell carcinoma has not been reported,the detailed mechanism of induction of apoptosis is not clear yet.Can doxorubicin induce apoptosis of FaDu by mediating endoplasmic reticulum stress?Therefore,we established the experimental system model of apoptosis of hypopharyngeal carcinoma cell line induced by doxorubicin.In this experimental platform,we investigated the molecular mechanism of hypopharyngeal carcinoma cell in the process of apoptotic stress of endoplasmic reticulum,and discussed the effect of endoplasmic reticulum stress on the apoptosis of tumor cells under drug action.It is hoped that the target of drug-mediated cell death should be found on the basis of molecular biology of tumor apoptosis.In the future,with a view to the development of chemotherapy drugs,We can design and develop effective drugs for ERS signaling pathways to contain hypopharyngeal cancer,which is the positive significance of this experiment.Materials and Methods:The human hypopharyngeal squamous cell carcinoma cell line(FaDu)was used as experimental material,1.The culture of FaDu cells.And then using SRB colorimetric method,in the doxorubicin treatment concentration and treatment time is different circumstances,the detection of cell survival.2.The expression level of apoptosis-related protein and endoplasmic reticulum stress-related protein were detected by Western blot in the presence of OμM,0.5μM,1 μM and 2μM doxorubicin in FaDu cells.3.The expression of stress-related proteins in the apoptotic-related protein and endoplasmic reticulum was detected by Western blot at different time after effective drug concentration of μM doxorubicin.4.0.5μM DOX and 0.5μM of Thapsigargin(TG)were used to detect the cell viability.The survival rate of apoptosis-related protein and endoplasmic reticulum stress-related protein was detected by Western blot.5.0.5μM DOXand ImM 4-PBA combined with SRB method to detect cell viability;Western blot detection of apoptosis-related protein and endoplasmic reticulum stress-related protein expression levels.Results1.The results showed that doxorubicin significantly reduced the relative viability of FaDu cells,and its effect was significant in time and dose dependent.2.The results showed that the expression of apoptosis-related proteins CASP8,CASP3 and PARP-1 increased,the expression of TNFRSF10B increased and the expression of CFLARL decreased,and the expression of CFLARL decreased with the increase of concentration and treatment time.The expression of EIF2AK3,ATF4 and DDIT3 decreased,and the expression of ERN1 and XBP1S increased.3.The results of Western blot showed that the expression of apoptosis-related proteins CASP8,CASP3 and PARP-1 increased,the expression of TNFRSF10B increased and the expression of CFLARL decreased.4.Doxorubicin combined with TG,and Western blot showed that the expression of apoptosis-related proteins CASP8,CASP3 and PARP-1 decreased,and the expression of ERN1 and XBP1S in endoplasmic reticulum increased significantly.5.Doxorubicin combined with 4-PBA,Western blot showed that apoptosis-related proteins CASP8,CASP3 and PARP-1 enhanced the expression of EIF2AK3,ATF4 and DDIT3 in endoplasmic reticulum stress-related proteins.Conclusions1.Doxorubicin can significantly inhibit the proliferation of FaDu cells and promote apoptosis.2.Doxorubicin can increase the expression of ERN1 and XBP1s in the endoplasmic reticulum stress protein.3..Doxorubicin could decrease the expression of EIF2AK3,ATF4 and DDIT3 in the endoplasmic reticulum stress protein.4.The experiments show that doxorubicin is involved in the induction of endoplasmic reticulum stress in the cell apoptosis.However,it was necessary to further study the apoptotic pathways of tumor cells and explore the molecular mechanism of tumorigenesis,progression,metastasis and drug resistance.For the tumor apoptosis induction therapy and reversal of tumor resistance,the experiments provide a new direction. |
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