Chaf1a Overexpression In Human Retinoblastoma Promotes Cell Proliferation And Suppresses Apoptosis

Purpose: Retinoblastoma causes significant human mortality especially in children. Although retinoblastoma may be treated if detected at early stage, however, it becomes destructive at advanced stages. The treatment involves surgery and chemotherapy. However, the chemotherapeutic agents have severe adverse effects. Therefore, development of viable drugs and identification of novel molecular therapeutic targets may enable efficient management of retinoblastoma. This study was designed to examine the expression profile of Chromatin Assembly Factor-1 (CHAF1A) and explore its therapeutic implications in retinoblastoma.Methods: The expression of CHAF1A was determined by qRT-PCR. MTT assay was used for the determination of the cell viability. Apoptosis was detected by acridine orange (AO)/ ethidium bromide (EB) and annexin V/propidium iodide (PI) assay. Cell cycle analysis was determined by flow cytometery. Protein expression was determined by western blot analysis.Results: The results showed that CHAF1A is significantly upregulated in human retinoblastoma, with 7.3 folds up regulation in retinoblastoma cells relative to normal cells. Knockdown of CHAF1A resulted in significant decline in the viability of the RB355 retinoblastoma cells. The flow cytometric analysis showed that knockdown of CHAF1A caused arrest of the RB355 cells at G0/G1 phase of the cell cycle. This was also linked with significant downregulation of cyclin D1 and cyclin E1. The AO/EB staining assay showed that CHAF1A knockdown promotes apoptosis which is associated with downregulation of Bcl-2 and upregulation of Bax.Conclusion: Taken together, these results suggest that CHAF1A is upregulated in retinoblastoma and regulates its proliferation and apoptosis. As such CHAF1A may act as biomarker as well as therapeutic target for the management of retinoblastoma.