Dihydroartemisinin/miR-29b combination therapy increases the pro-apoptotic effect of dihydroartemisinin on cholangiocarcinoma cell lines by regulating Mcl-1 expression.

Background: Cholangiocarcinoma is a malignant tumor that originates from the neoplastic transformation of bile duct epithelial cells.

Objectives: To investigate the role of DHA and miR-29b on the proliferation and apoptosis of cholangiocarcinoma cells, and to explore whether DHA exerted its role through the miR-29b/Mcl-1 signaling pathway.

Material And Methods: Human cholangiocarcinoma cell lines HUCCT-1 and FRH0201 were treated with dihydroartemisinin (DHA) and DHA+miR-29b. The inhibitory effects of DHA and miR-29b on proliferation were detected using MTT assay. The effects of DHA and miR-29b on apoptosis were detected using flow cytometry (FCM). The mRNA and protein expressions of Mcl-1L and Mcl-1S were evaluated with reverse transcriptase polymerase chain reaction (RT-PCR) and western blotting, respectively.

Results: The DHA increased miR-29b expression in HUCCT-1 and FRH201 cells. The MTT assay showed that DHA+miR-29b combination therapy promoted the inhibition effects on the proliferation of HUCCT-1 and FRH201 cells. The FCM results revealed that DHA and miR-29b combination therapy increased the apoptosis of HUCCT-1 and FRH201 cells. The RT-PCR and western blotting analysis found that DHA+miR-29b combination therapy significantly decreased Mcl-1L expression and increased Mcl-1S expression in both HUCCT-1 and FRH201 cells. The Mcl-1S:Mcl-1L ratio was notably higher in the DHA+miR-29b combination therapy group than in the control group and DHA therapy group, in both HUCCT-1 and FRH201 cells.

Conclusions: The DHA and miR-29b have a pro-apoptotic effect on cholangiocarcinoma cells through the DHA/miR-29b/Mcl-1 pathway, possibly by upregulating the expression of the pro-apoptotic protein Mcl-1S and thus increasing the proportion of Mcl-1S protein among the total amount of Mcl-1 protein.