Human positive coactivator 4 (PC4) is involved in the progression and prognosis of astrocytoma

Astrocytoma is the most common primary brain tumor and it is associated with poor prognosis. Accumulating evidences suggest that certain molecular abnormalities or genetic mutations are associated with its progression and prognosis. Human transcriptional coactivator 4 (PC4), originally identified as a transcriptional coactivator then as a DNA replication and repair factor has been shown to be involved in chromatin organization. Recently, it is reported to function both as tumor suppressor and promoter depending on the cellular settings. In the present study, we for the first time demonstrated that the expression of PC4 in astrocytoma was upregulated as assessed by western blot and immunohistochemical staining. Moreover, elevated PC4 expression was strongly correlated with the progression of astrocytoma. Furthermore, high PC4 expression was also associated with poor overall survival. Finally, in vitro study demonstrated that siRNA mediated PC4 downregulation significantly inhibited the proliferation and invasiveness of human glioma cells. These results suggested that PC4 might play a role in human astrocytoma progression and may be used as a novel indicator for the prognosis of astrocytoma patient.