Study On The Effect And Mechanism Of Calreticulin In Promoting The Malignant Progression Of Nasopharyngeal Carcinoma Cells

Objective:To clarify the role of Calreticulin(CALR/CALR)in the occurrence and development of nasopharyngeal carcinoma,and toelucidate the molecular mechanism that CALR promotes the growth of nasopharyngeal carcinoma cells by activating the STAT3 signaling pathway,and to provide molecular targets for the diagnosis and treatment of nasopharyngeal carcinoma(NPC).Methods:1.Wax blocks and fresh clinical samples of NPC tissues were collected to detect the expression of CALR in NPC tissues by immunohistochemistry and Quantitative real time-PCR(q RT-PCR),to assess the association of CALR expression with the clinicopathological characteristics and prognosis of NPC,to investigate the clinical effort2.Plate cloning experiment,CCK-8 cell proliferation experiment,scratch experiment,Transwell migration,invasion experiment,Real-time PCR,Western blot and other experimental methods were used to analyze the effect of knockdown of CALR expression on the biological behaviors of nasopharyngeal carcinoma cells such as proliferation,migration and invasion,as well as the expression of related molecules in the STAT3 signaling pathway,and to investigate the effect and molecular mechanism of CALR on the development of nasopharyngeal carcinoma.Results:1.The expression of CALR protein was significantly higher in NPC tissues,and the expression of CALR m RNA levels in nasopharyngeal carcinoma tissues was also significantly increased(P <0.001).In addition,compared with immortalized normal nasopharyngeal epithelial NP69 cells,the expression of CALR protein increased in various degrees in NPC cell lines(CNE1,CNE2,HONE1,C666-1,HNE1,HNE2 and 5-8F).2.High expression of CALR was positively correlated with clinical staging(P = 0.003)and metastasis(P = 0.023)of NPC;Survival analysis showed that the progression-free survival(PFS)(P = 0.013)and Overall survival OS(P = 0.003)of patients of NPC patients with high expression of CALR were shorter.COX multi-factor regression analysis found that the high expression of CALR is an independent predictor of poor prognosis for NPC patients.3.The growth,invasion and metastasis of CNE2 and HONE1 cells were significantly weakened after knockdown of CALR compared with control group.4.Compared with the empty vector group,the levels of total STAT3,p-STAT3 protein expression significantly decreased in the CNE2 and HONE1 cells after silencing CALR.Conclusions:1.CALR is highly expressed in NPC and can promote the growth of NPC.The mechanism is related to the activation of the STAT3 signaling pathway.2.CALR is a potential molecular marker for monitoring the progress and prognosis of NPC.