Aberrant Expressions Of NUSAP1 In Glioma And Its Fuction In Glioma Cell

[BACKGROUND]Glioma is one of the most common and frequnet malignant tumor.it makes up about 40% of all brain and central nervous system tumors.highly invasion,high recurrence rate of postoperative still threat the health of patients.the main therapeutic method is surgery,combining with chemotherapy and radiotherapy,because of the highly invasion and rich blood supply,it is impossible to completely remove all lesions with surgery,five-year survival rate less than 10% in high grade glioma(WHO Ⅲ、Ⅳ level), therefore, it is necessory to explore the molecular biological mechanism in glioma,looking for new methods of diagnosis and treatment is very important.Nucleolar-spindle associated protein 1(NUSAP1)is a microtubule-associated protein that plays a central role in spindle assembly and act as a key regulator to warrant the process of cell division,the level of NUSAP1 reach its peak in G2 stage and abruptly drop in M stage.The levels of NUSAP1 expression were strictly regulated and dynamically changed during different stages of the cell cycle.It was first found in 2003,recent studies has found it overexpressed in breast cancer,prostate cancer,lung cancer and so on.The expression level of NUSAP1 seem to be related to the invasiveness and prognosis of the tumors,but there is no study on glioma,and the function of NUSAP1 in glioma’s development and progression has not been report.[OBJECTIVE]Owing to the important function of NUSAP1 in the cell cycle,and it ofter overexpressed in many cancers,the disturb of function may associated with the development and recurrence of cancer.This study will investigate the expression level in glioma and analysis the molecular mechanisms of NUSAP1 in glioma cell lines.[METHODS](1).We collect 30 cases fresh samples of brain glioma and normal brain(epileptic)sample of 10 cases in surgery.Using quantitative real-time PCR,Western-blot and immunohistochemical to detect the level of NUSAP1 in samples.(2).Using Western-blot technology to detect the level of NUSAP1 in normal glial cell (HEB)and glioma cells(LN229, T98G, U87,U251),and utilizing SiRNA,lentivirus to knockdown the expression of NUSAP1 in glioma cell lines.(3).Using CCK-8 method to analysis the cell proliferation activity,transwell to test the cell migration and aggressive capability.Flow cytometry was used to determined cell cycle and apoptosis and investigate the mechanism of apoptosis.[RESULTS](1).NUSAP1 is overexpressed in glioma tissue samples and the level of NUSAP1 is increased with glioma grade.The expression of NUSAP1 in normal brain tissue is not obvious.(2).NUSAP1 is also overexpressed in glioma cell lines,knockdown the NUSAP1 expression will reduce the ability of cell proliferation invasion,cell cycle will be disorder and stagnate in G1 stage,Finally the number of cell apoptosis will increase.(3).Using Western-blot to detect the index of cell apoptosis,we have found four genes p21,p53,caspase3,capase8 expression increased in LN229 which inhibit the expression of NUSAP1[CONCLUSION]Our study has firstly found that NUSAP1 overexpressed in glioma tissue samples and glioma cell lines.inhibit the expression of NUSAP1 in glioma cells will led it stay in G1 stage,and reduce the capacity of proliferation and invasion,cell apoptosis increased,we found p21,p53,aspase3,capase8 expression increased in LN229 which inhibit the expression of NUSAPl,p21 and p53 can constitute G1 period checkpoint, Due to inhibit NUSAPI expression,cells stay in G1 stage,this may activated the p21 gene and p53 gene,in this way,it may accelerate the cell apoptosis progression.NUSAP1 may be a oncogene in glioma and its high expression maybe take part in the glioma development and progression.NUSAPl may offers a new therapeutic target of drugs to promote tumor cell apoptosis.