KiSS1 Gene Suppresses Metastasis Of Nasopharyngeal Cancer Via Activation Of The ERK1/2 Pathway

Objective: To define the underlying mechanism of metastasis inhibition of KiSS1 and its receptor gene(h OT7T175 or GPR54)in NPC.Methods: Firstly,the NPC cells that with high metastasis(SUNE-1-5-8F)or low metastasis(SUNE-1-6-10B)were cultured with DMEM culture for the assay of the expression of KiSS1 and KiSS1-R genes by RT-PCR and Western blot.Secondly,the KiSS1 and KiSS1-R gene were overexpressed in SUNE-1-5-8F separately or together by p SIREN-Retro Q retroviral vector.Thirdly,the metastasis of SUNE cells were assayed by wound healing and Transwell assay,and the expression of FAK,p-FAK,p-ERK1/2 and EZR was measured by Western blot after the overexpression of KISS1 and its receptor genes.Fourthly,after activation of ERK1/2 pathway was blocked with inhibitor PD98059,the metastasis was assayed by Transwell assay,the expression of p-FAK,EZR was measured by Western blot.Finally,the expression of KiSS1 and KiSS1-R was interfered with si RNA and then the metastasis and expression of p-ERK1/2 was assayed.Results:(1)By using RT-PCR,we firstly found the expression of KiSS1 gene was highly expressed in SUNE-1-6-10 B cells which has low metastasis when compared with SUNE-1-5-8F cells that has high metastasis.(2)By Western blot,we found the expression of KiSS1,KiSS1-R,FAK and p-FAK were negative related with the metastasis of NPC,while the expression of EZR was correlative with the metastasis of NPC.(3)The metastasis of the SUNE-1-5-8F cells were significantly suppressed during wound healing or Transwell assay after KiSS1 and KiSS1-R overexpressed separately or together.(4)Besides,the expression of p-FAK and p-ERK1/2 pathway was significantly increased,while the content of EZR was decreased in SUNE-1-5-8F assayed by Western blot.(5)The metastasis suppression induced by overexpression of KiSS1 and KiSS1-R was reversed after ERK1/2 pathway was blocked with the inhibitor PD98059.(6)Besides,after the pathway was blocked,the increased phosphorylation of ERK1/2 pathway and phosphorylation of FAK,and the decreased EZR were reversed.(7)By using si RNA interference,we found the metastasis of the NPC cells were increased.Conclusion: By combing the RT-PCR,Western blot,Transwell assay,and si RAN interference,we can conclude the sufficient and necessary role of KiSS1 and KiSS1-R that suppressing the metastasis of NPC cells by activation of p-FAK and inhibition of EZR through phosphorylation of ERK1/2 pathway.