An Experimental Study On The Expression Levels Of KAI1/CD82Gene In Human Nasopharyngeal Cell Lines With Different Metastasis Ability

Background: Nasopharyngeal carcinoma is one of the most malignant cancers whichare hazarding the people’s health and life in the world. Tumor invasion and metastasisis not only the malignant marker and characteristics of nasopharyngeal carcinoma, butalso the main cause of failure to cure and lose their life of the patients withnasopharyngeal carcinoma. It is a complex biological behavior that dealt with manyfactors, genes, signal pathways and processes. It has been reported that both positiveregulation gene and negative regulation gene were involved in the regulative processof invasion and metastasis of nasopharyngeal carcinoma. The KAI1gene may be oneof the positive regulation genes. The KAI1gene belongs totransmembrance-4-superfamily (TM4SF) of cell surface glycoprotein, all of whichhave four transmembrane domains and one large extracellular domain.Down-regulation of KAI1gene mRNA expression has been found in some commonhuman malignancies, including prostatic, pancreatic, lung, colon, and bladder cancers.These observations suggest that the presence of down-regulation of KAI1genemRNA expression might influence the metastatic ability of cancer cells, and it hasbeen proved that low expression of tumor metastasis suppressor gene KAI1wasclosely correlated with the high metastatic ability and poor prognosis of patient withnasopharyngeal carcinoma. The mechanism of KAI1down-regulation is still not to beilluminated.Objective: The purpose/aim of this study is to Culture the growth features of fivekinds of nasopharyngeal carcinoma cells with different metastasis ability invitro(CNE-1、CNE-2Z、SUNE-1、SUNE-1-5-8F、SUNE-1-6-10B). To determine theexpression and the difference of KAI1gene mRNA and protein among differentmetastatic potential of human nasopharyngeal carcinoma cell lines. We also wanted toprovide the cell theory foundation for the next experiment of our research group. Methods:1. Real-time quantitative PCR was applied to detect KAI1/CD82genemRNA expression in five cell lines of nasopharyngeal cancer.2.Immunohistochemistry technique and Western blot was applied to detect the locationand expression of KAI1/CD82protein in five cell lines of nasopharyngeal cancer.Results:1. In human nasopharyngeal cell lines (CNE-1、CNE-2Z、SUNE-1、SUNE-1-5-8F、SUNE-1-6-10B) with the different metastasis ability, there was allpositive expression of Kiss-1/hOT7T175mRNA. With the increased metastasisability，KAI1/CD82mRNA expression levels decreased gradually(p<0.05).2. Theexpression of KAI1/CD82in human nasopharyngeal cell lines explored byWestern-blot. The result showed that KAI1/CD82is high-expressed inSUNE-1-6-10B and CNE-1, especially in SUNE-1-6-10B.3. The identification ofKAI1/CD82in human nasopharyngeal cell lines detected by immunohistochemistrytechnique. The result indicated KAI1/CD82was expressed at plasma membrane andcytoplasm.Conclusions:1. The expression of KAI1/CD82in the mRNA levels was positivecorrelation with which protein expression levels. With the increasing expression ofKAI1/CD82mRNA, the expression of KAI1/CD82protein also showed an increasingtrend.2. The protein and mRNA levels of KAI1/CD82highly expressed in humannasopharyngeal cell line (SUNE-1-6-10B) with low metastasis ability, lowlyexpressed in the other human nasopharyngeal cell lines (CNE-1、CNE-2Z、SUNE-1、SUNE-1-5-8F) with high metastasis ability. These indicated that KAI1/CD82mayplay an important role in metastasis of nasopharyngeal carcinoma.