Effects of berberine on the secretion of cytokines and expression of genes involved in cell cycle regulation in THP-۱ monocytic cell line

Objective(s): Current acute myeloid leukemia (AML) therapeutic strategies have irreversible side-effects. Berberine (BBR) is an isoquinoline alkaloid, which has been known as an aryl hydrocarbon receptor (AhR) ligand. AhR is a cytoplasmic receptor, which is involved in the regulation of cellular and immune responses. Here, we investigated the expression profile of genes involved in the cell cycle and different cytokines upon BBR-mediated AhR activation on AML THP-۱ cell line. Materials and Methods: THP-۱ cells and normal monocytes were treated with different concentrations of BBR (۱۰ μM, ۲۵ μM, ۵۰ μM, and ۱۰۰ μM) for ۲۴ and ۴۸ hr. The cell viability was measured by MTT assay. Real-time RT-PCR was conducted to evaluate the expression of AhR, cytochrome P۴۵۰ ۱A۱ (CYP۱A۱), interleukin ۱ beta (IL۱β), p۲۱, p۲۷, cyclin-dependent kinase ۲ (CDK۲) and p۵۳. Cellular expression of AhR was also assessed using immunofluorescence method. ELISA was used to determine the level of IL-۱۰ and IL-۱۲ cytokines. Results: BBR inhibits the proliferation of THP-۱ cells in a dose- and time-dependent manner with minimal toxicity on normal monocytes. Phorbol ۱۲-myristate ۱۳-acetate (PMA) treatment increased the cellular expression of AhR. The AhR target genes (CYP۱A۱, IL۱β) were overexpressed upon BBR treatment. BBR downregulated Cdk۲ and upregulated p۲۱, p۲۷ and p۵۳ genes in THP-۱ cells. IL-۱۰ was significantly increased upon BBR treatment, while IL-۱۲ was not significantly changed in all combinations. Conclusion: BBR could be introduced as an effective chemotherapeutic agent against AML by giving rise to the expression of CDK inhibitors and anti-inflammatory cytokines and downregulation of CDK۲.

Keywords:

Acute myeloid leukemia , Aryl hydrocarbon receptor , Berberine , Cell cycle regulation , THP-۱