CEP55 promotes cell proliferation and inhibits apoptosis via the PI3K/Akt/p21 signaling pathway in human glioma U251 cells

Human glioma is one of the major malignancies worldwide with an increased mortality rate. Centrosomal protein of 55 kDa (CEP55) is an essential component of the CEP family and has been identified as a prognostic marker for multiple types of cancer. However, the function of CEP55 during glioma tumorigenesis remains unclear. In the present study, the data derived from the Oncomine database indicated that the expression of CEP55 is increased in glioma tissues compared with normal tissues. Furthermore, the expression of CEP55 was also increased at the level of mRNA and protein in glioma cell lines compared with normal human astrocytes. The knockdown of CEP55 expression inhibited the proliferation of glioma U251 cells, whereas overexpression of CEP55 induced the proliferation of U251 cells. Flow cytometric analysis indicated that the knockdown of CEP55 resulted in an increased number of cells arrested at G(2)/M phase, and apoptosis was promoted. Further investigations revealed that the overexpression of CEP55 increased the phosphorylation of Akt and inhibited the activity of p21. By contrast, the knockdown of CEP55 resulted in the opposite effects. Taken together, the results of the present study suggested that CEP55 regulated the proliferation of glioma cells, further attributing to the carcinogenesis and progression of glioma via the PI3K/Akt/p21 signaling pathway. Therefore, CEP55 may be a novel therapeutic target for the treatment of glioma.