Y-box Binding Protein 1 Is Involved in Regulating the G2/M Phase of the Cell Cycle.

BACKGROUND/AIM: The transcription factor Y-box-binding protein 1 (YB1) is overexpressed in many types of human cancers. YB1 regulates the G1 phase of the cell cycle by controlling transcription of G1 regulators. Here, we report that YB1 is also involved in regulating G2/M phase.

MATERIALS AND METHODS: YB1-depleted TKO cells were subjected to quantitative reverse transcription-polymerase chain reaction and cell-cycle analysis. RNA immunoprecipitation (RIP)-chip assay was performed using anti-YB1 antibodies. Precipitated RNAs were subjected to microarray analysis.

RESULTS: Silencing YB1 inhibited the proliferation of TKO cells, which lost the machinery required for G1 phase arrest. Cell-cycle analysis showed that silencing YB1 caused G2/M phase cell-cycle arrest. RIP-chip assay showed that YB1 associated with mRNA of multiple cell-cycle-related genes, including G2/M phase regulators.

CONCLUSION: YB1 positively regulates not only the G1 phase but also G2/M phase by regulating multiple cell-cycle-related genes.