| Thymoquinone enhances hypomethylation of SHP-1 and inhibits JAK/STAT signaling pathway in K562 chronic myeloid leukemia cells |
| Paper ID : 1075-ISCBAS |
| Authors |
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Hamid Ali Nagi Al-Jamal * Univesiti Sultan Zainal Abdin |
| Abstract |
| Epigenetic silencing of tumour suppressor genes (TSGs) plays a crucial role in the development of chronic myeloid leukemia (CML). SHP-1 function as TSG and negatively regulates JAK/STAT signaling. Restoration of SHP-1 expression through de-methylation provides therapeutic targets in several cancers. Thymoquinone (TQ), a constituent of Nigella sativa seeds, has shown anticancer activities in several cancers. However, the effect of TQ on methylation is not fully clear. Therefore, this study aimed to assess TQ’s ability to re-express SHP-1 through modifying DNA methylation in K562 CML cells. The effect of TQ on apoptosis and cell cycle progression was investigated using Annexin V-FITC/PI apoptosis detection kit and fluorometric-red cell cycle assay kit, respectively. The methylation status of SHP-1 was studied by pyrosequencing analysis. The expression of SHP-1, DNMT1, DNMT3A, DNMT3B, TET2, and WT1 was determined using RT-qPCR. The protein levels and the phosphorylation status of JAK2, STAT3, and STAT5 were assessed using Jess western analysis. TQ significantly downregulated DNMT1, DNMT3A, and DNMT3B and upregulated TET2, and WT1. This led to hypomethylation and re-expression of SHP-1 which was associated with inhibition of JAK/STAT signaling resulting in apoptosis induction and cell cycle arrest in K562 CML cells. These findings suggest that TQ enhances apoptosis and cell cycle arrest in CML cells by inhibiting JAK/STAT signaling through hypomethylation and re-expression of JAK/STAT negative regulator genes. |
| Keywords |
| Keyword: Thymoquinone, CML, hypomethylation, SHP-1, DNMT1, DNMT3A, DNMT3B, JAK/STAT |
| Status: Abstract Accepted (Oral Presentation) |