title: Silencing of TBX20 gene expression in rat myocardial and human embryonic kidney cells leads to cell cycle arrest in G2 phase.
abstract: Congenital heart diseases (CHDs) are the most common birth defects due to abnormal cardiac development. The T-box 20 (TBX20) gene is a member of the T‑box family of transcription factors and encodes TBX20, which is essential for early heart development. In the present study, reduced TBX20 expression was observed in CHD tissue samples compared with normal tissues, and the function of TBX20 in Rattus norvegicus myocardial cells [H9c2(2-1)] and human embryonic kidney cells (HEK293) was investigated. TBX20 was silenced in H9c2 and HEK293 cells via transfection of small interfering RNA and short hairpin RNA duplexes, respectively, and TBX20 mRNA and protein levels were subsequently examined using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) and western blot analysis. Cell proliferation was assessed using a cell counting kit and proliferating cell nuclear antigen expression was determined by western blotting. Analysis of cell apoptosis was achieved by annexin V‑fluorescein isothiocyanate/propidium iodide staining and a fluorometric terminal deoxynucleotidyl transferase dUTP nick‑end labeling system. Cell cycle analysis was achieved using fluorescence‑activated cell sorting, and, an RT‑qPCR array was used to profile the expression of TBX20‑related genes. Silencing of TBX20 in H9c2 and HEK293 cells significantly inhibited cell proliferation, induced cell apoptosis and led to G2/M cell cycle arrest. A reduction in cyclin B1 mRNA levels and an increase in cyclin‑dependent kinase inhibitor 1B mRNA levels was observed, which indicated that cells were arrested in G2 phase. Concurrently, the mRNA levels of GATA binding protein 4 were increased in both cell lines, which may provide an explanation for the abnormal cardiac hypertrophy observed in patients with congenital heart disease. These results suggest that TBX20 is required for heart morphogenesis, and inhibition of TBX20 expression may lead to the suppression of cell proliferation and cell cycle arrest.
authors: Department of Medical Genetics, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, P.R. China.
authors: Peiyan
authors: P
authors: Liu
authors: Department of Medical Genetics, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, P.R. China.
authors: Yueling
authors: Y
authors: Sun
authors: Department of Laboratory Medicine, 202 Hospital of People's Liberation Army, Shenyang, Heping 110003, P.R. China.
authors: Guangbin
authors: G
authors: Qiu
authors: Department of Pediatrics, The First Affiliated Hospital, China Medical University, Shenyang, Heping 110001, P.R. China.
authors: Hongkun
authors: H
authors: Jiang
authors: Department of Medical Genetics, College of Basic Medical Science, China Medical University, Shenyang, Liaoning 110122, P.R. China.
authors: Guangrong
authors: G
authors: Qiu
mesh_terms: D000818:Animals; D017209:Apoptosis; D002460:Cell Line; D049109:Cell Proliferation; D004847:Epithelial Cells / Q000166:cytology* / Q000378:metabolism; D059565:G2 Phase Cell Cycle Checkpoints; D057809:HEK293 Cells; D006801:Humans; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D020825:T-Box Domain Proteins / Q000235:genetics*
chemical_list: D034741:RNA, Small Interfering; D020825:T-Box Domain Proteins; C420984:TBX20 protein, human; C000612542:TBX20 protein, rat