Silencing HIWI suppresses the growth, invasion and migration of glioma cells.

The HIWI gene is one of the members of the PIWI gene family that is important for stem cell self‑renewal and expressed highly in certain human tumors. Some studies have demonstrated that HIWI plays a key role in the development of tumors in cervical, colon and liver cancer. Previous studies have demonstrated that HIWI is associated with prognosis of patients with glioma. However, there is no report on the analysis of HIWI in the biological characteristics of glioma cells. The aim of the study was to investigate whether HIWI plays an important role in the progress of glioma. Silencing HIWI inhibited cell proliferation by promoting apoptosis and increased cell cycle arrest. The expression of proteins related to apoptosis and the cell cycle, including p21, cyclin D1, Bcl-2, and Bax was significantly altered. Moreover, knockdown of HIWI inhibited the migration and invasion of glioma cells by reducing the expression of MMP-2 and MMP‑9. Furthermore, we found that reduction of HIWI inhibited tumor growth in vivo. These findings suggest that HIWI is an oncogene involved in the progression of glioma.