Khandakar A S M Saadat1. 1. Section of Molecular Craniofacial Embryology, Department of Maxillofacial and Neck Reconstruction, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University.
Abstract
UNLABELLED: ARID3A is a member of the AT-rich interaction domain (ARID) family of DNA-binding proteins. ARID3A was isolated as proteins binding to E2F1, and stimulates transcription mediated by the E2F transcription factor that plays a central role in regulating cell cycle progression. However, the function of ARID3A in E2F-target-gene expression has not been fully understood. METHODS: Gene-silencing and overexpression experiments were carried out using siRNA and recombinant adenoviruses, respectively. E2F responsive gene expression was measured by RT-PCR. Effects of ARID3A silencing on DNA synthesis and cell growth were determined by EdU incorporation and colony formation assay, respectively. RESULTS: siRNA mediated gene silencing of ARID3A blocked the transcription of E2F-target genes, such as E2F1, p107, CDC2 and CDC6 in normal human dermal fibroblasts (NHDFs). Although adenoviral-mediated overexpression of ARID3A did not up-regulate the transcription of these E2F-target genes in quiescent NHDFs, E2F1 overexpression was unable to overcome the blockade of CDC6 expression by ARID3A silencing. Furthermore, ARID3A silencing attenuated S phase entry of NHDFs, and suppressed growth of human tumor cell lines. CONCLUSION: These results indicate that ARID3A plays an important role for E2F-mediated transcriptional activation and cell growth.
UNLABELLED: ARID3A is a member of the AT-rich interaction domain (ARID) family of DNA-binding proteins. ARID3A was isolated as proteins binding to E2F1, and stimulates transcription mediated by the E2F transcription factor that plays a central role in regulating cell cycle progression. However, the function of ARID3A in E2F-target-gene expression has not been fully understood. METHODS: Gene-silencing and overexpression experiments were carried out using siRNA and recombinant adenoviruses, respectively. E2F responsive gene expression was measured by RT-PCR. Effects of ARID3A silencing on DNA synthesis and cell growth were determined by EdU incorporation and colony formation assay, respectively. RESULTS: siRNA mediated gene silencing of ARID3A blocked the transcription of E2F-target genes, such as E2F1, p107, CDC2 and CDC6 in normal human dermal fibroblasts (NHDFs). Although adenoviral-mediated overexpression of ARID3A did not up-regulate the transcription of these E2F-target genes in quiescent NHDFs, E2F1 overexpression was unable to overcome the blockade of CDC6 expression by ARID3A silencing. Furthermore, ARID3A silencing attenuated S phase entry of NHDFs, and suppressed growth of humantumor cell lines. CONCLUSION: These results indicate that ARID3A plays an important role for E2F-mediated transcriptional activation and cell growth.