Knockdown of immature colon carcinoma transcript-1 inhibits proliferation of glioblastoma multiforme cells through Gap 2/mitotic phase arrest

"Glioblastoma multiforme" (GBM) is the frequent form of malignant glioma. Immature colon carcinoma transcript-1 (ICT1) is essential for cell vitality and mitochondrial function and has been recognized in several human cancers. In the study reported here, we attempted to evaluate the functional role of ICT1 in GBM cells. Lentivirus-mediated RNA interference (RNAi) was applied to silence ICT1 expression in human GBM cell lines U251 and U87. Cell proliferation was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony-formation assays. Cell-cycle progression was determined by flow cytometry with propidium iodide staining. The results revealed that lentivirus-mediated short hairpin RNA (shRNA) can specifically suppress the expression of ICT1 in U251 and U87 cells. Functional investigations proved for the first time, as far as we are aware, that ICT1 knockdown significantly inhibited the proliferation of both cell lines. Moreover, the cell cycle of U251 cells was arrested at Gap 2 (G2)/mitotic (M) phase after ICT1 knockdown, with a concomitant accumulation of cells in the Sub-Gap 1 (G1) phase. This study highlights the crucial role of ICT1 in promoting GBM cell proliferation, and provides a foundation for further study into the clinical potential of lentivirus-mediated silencing of ICT1 for GBM therapy.