Abstract:
CCNA1 is a gene locating on chromosome 13 at region q12.3-q13. The protein encoded by this gene is cyclin A1. Cyclin A1 is a member of the cyclin family whose members are able to control the progression of cells through the cell cycle in osteosarcoma cell and leukemia cells. Furthermore, CCNA1 is involved in double strand break repair by non-homologous end-joining and it was CCNA1 that is methylated in several cancers. From data mentioned above suggests that it might be a tumor suppressor gene. The aim of this study is to substantiate that CCNA1 is a tumor suppressor gene. The expression of CCNA1 siRNA in HN12 head and neck cancer cell was suppressed by vary concentration of siRNA. We then evaluated the changes in CCNA1 expression by real-time PCR. From experiment after knockdown CCNA1 gene, cells had increased significant in DNA double-strand break at 0, 2, 4 and 48 hours after UV-C irradiation when compared with control group. This result confirmed function of CCNA1 in double strand break repair. Knockdown of CCNA1 gene in HN12 did not significant effect cell viability. In part of detected the hallmark of cancer, from experiment after knockdown CCNA1 gene, cells had significant decreas in proliferation at 2 and 4 hours after UV-C irradiation but significantly increase at 48 hours after UV-C irradiation. Knockdown of CCNA1 gene did not affect apoptosis. The invasion of cells significant increase after knockdown CCNA1 gene and induced DNA double strand break when compare with control group. In conclusion, the CCNA1 gene is involved in double strand break repair and plays a role as a tumor suppressor gene in HN12 head and neck cancer cells.