Effects of sense and antisense centromere/kinetochore complex protein-B (CENP-B) in cell cycle regulation

This paper investigates the effects of sense and antisense centromere/kinetochore complex protein-B (CENP-B) in cell cycle regulation. Full-length cenpb cDNA was subcloned into pBI-EGFP eukaryotic expression vector in both sense and antisense orientation. HeLa-Tet-Off cells were transfected with sense or antisense cenpb vectors. Sense transfection of HeLa-Tet-Off cells resulted in the formation of a large centromere/kinetochore complex, and apoptosis of cells following several times of cell division. A stable an- tisense cenpb transfected cell line, named HACPB, was ob- tained. The centromere/kinetochore complex of HACPB cells became smaller than control HeLa-Tet-Off cells and scat- tered, and the expression of CENP-B was down-regulated. In addition, delayed cell cycle progression, inhibited malignant phenotype, restrained ability of tumor formation in nude mice, and delayed entry from G2/M phase into next G1 phase were observed in HACPB cells. Furthermore, the ex- pression of cyclin-dependent kinases (CDKs), cyclins, and CDK inhibitors (CKIs) were modulated during different phases of the cell cycle. CENP-B is an essential protein for the maintenance of the structure and function of centro- mere/kinetochore complex, and plays important roles in cell cycle regulation.

This paper investigates the effects of sense and antisense centromere/kinetochore complex protein-B （CENP-B） in cell cycle regulation. Full-length cenpb cDNA was subcloned into pBI-EGFP eukaryotic expression vector in both sense and antisense orientation. HeLa-Tet-Off cells were transfected with sense or antisense cenpb vectors. Sense transfection of HeLa-Tet-Off cells resulted in the formation of a large centromere/kinetochore complex, and apoptosis of cells following several times of cell division. A stable antisense cenpb transfected cell line, named HACPB, was ob- tained. The centromere/kinetochore complex of HACPB cells became smaller than control HeLa-Tet-Off cells and scattered, and the expression of CENP-B was down-regulated. In addition, delayed cell cycle progression, inhibited malignant phenotype, restrained ability of tumor formation in nude mice, and delayed entry from G2fM phase into next G1 phase were observed in HACPB cells. Furthermore, the expression of cyclin-dependent kinases （CDKs）, cyclins, and CDK inhibitors （CKIs） were modulated during different phases of the cell cycle. CENP-B is an essential protein for the maintenance of the structure and function of centromere/kinetochore complex, and plays important roles in cell cycle regulation.