Study On The Mechanism Of Annexin 1 Inhibiting Migration And Invasion Of Nasopharyngeal Carcinoma

[Objective] Nasopharyngeal carcinoma(NPC)is a common head and neck tumor in Southeast Asia,with morbidity and mortality ranking the first among head and neck tumors.In our previous study,we used laser capture microdissection combined with proteomics analysis to find that the expression of Annexin A1(Annexin 1)was significantly decreased in nasopharyngeal carcinoma compared with normal nasopharyngeal mucosal tissues,and was associated with differentiation and/or invasion and metastasis potential of nasopharyngeal carcinoma cells.Subsequently,bioinformatics analysis combined with immunoprecipitation showed that Annexin 1 could interact with vimentin in the less invasive NPC cell line 6-10B(high expression of Annexin 1),and it was observed that after knockdown of Annexin 1 in NPC 6-10 B,the cell morphs from polygons to spindles,Vimentin is one of the markers of Epithelial mesenchymal transformation(EMT),suggesting that Annexin 1 May inhibit in vitro migration and invasion of NPC cells through EMT.Therefore,this study aims to explore the molecular mechanism of Annexin 1 inhibiting the migration and invasion of NPC.[Methods] 1.RTq-PCR and Western blot were used to detect the expression of Annexin 1,N-cadherin and Vimentin in 5-8F and 6-10 B NPC cells,respectively.2.Annexin 1(+)high expression plasmid and no load plasmid were transfected into highly invasive NPC 5-8F cells with low expression of Annexin 1 by liposome transfection technique.Cell lines of 5-8FAnnexin 1(+)and control 5-8F-Annexin 1(-)up-regulated were constructed.Annexin 1 low RNAi expression plasmid and corresponding no-load plasmid were transfected into low invasive NPC 6-10 B cells with high Annexin 1 expression,respectively.Annexin 1 down-regulated 6-10b-RNAi(+)and control 6-10b-RNAi(-)cell lines were constructed.3.RTq-PCR and Western blot were used to detect 5-8F,5-8FAnnexin 1(-),5-8F-Annexin 1(+),6-10 B,6-10B-RNAi(-)and 6-10BRNAi(+)cells.The m RNA and protein expression levels of Annexin 1,N-cadherin and Vimentin were analyzed,and the effect of Annexin 1expression level on the expression of N-cadherin and Vimentin and their correlation were analyzed.4.Cell scratch healing and Transwell migration and invasion experiments were used.The ability of migration and invasion in 5-8F,5-8F-Annexin 1(-),5-8F-Annexin 1(+),6-10 B,6-10B-RNAi(-)and 6-10B-RNAi(+)of NPC cells were detected.[Results] 1.RTq-PCR and Western blot results showed that Annexin1 m RNA relative expression level and protein expression water in 5-8F cells were significantly lower than those in 6-10 B cells.m RNA relative expression levels and protein expression levels of N-cadherin and Vimentin were significantly higher than those of 6-10 B cells(P<0.05);2.Fluorescence microscope observation showed: Annexin 1 high expression of nasopharyngeal carcinoma 5-8F-Annexin 1(+)was successfully constructed,and the control 5-8F-Annexin 1(-)cell line was successfully constructed.Annexin 1 low expression of nasopharyngeal carcinoma 6-10b-RNAi(+)and control 6-10b-RNAi(-)cell lines;3.RTq-PCR and Western blot results showed that the m RNA and protein expression levels of Annexin 1 in 5-8F-Annexin 1(+)cells were significantly higher than those in 5-8F and 5-8F-Annexin 1(-)cells.The m RNA relative expression levels and protein expression levels of Ncadherin and Vimentin were significantly lower than those of 5-8F and5-8F-annexin 1(-)cells.Annexin 1 m RNA relative expression and protein expression levels in 6-10B-RNAi(+)cells were significantly lower than those in 6-10 B and 6-10B-RNAi(-)cells.m RNA relative expression levels and protein expression levels of N-cadherin and Vimentin were significantly higher than those of 6-10 B and 6-10B-RNAi(-)cells(P<0.05);4.The results of cell scratch healing and Transwell migration and invasion showed that the migration and invasion ability of 5-8F-Annexin1(+)cells was significantly reduced compared with 5-8F and 5-8FAnnexin 1(-)cells.The migration and invasion ability of 6-10B-RNAi(+)cells was significantly higher than that of 6-10 B and 6-10B-RNAi(-)cells(P<0.05);[Conclusion] 1.Annexin 1 was negatively associated with Ncadherin and Vimentin in nasopharyngeal carcinoma cells.2.Annexin 1 May affect in vitro migration and invasion of nasopharyngeal carcinoma cells by influencing the expression of Ncadherin and Vimentin to induce EMT.