Millepachine, a novel chalcone, induces G 2 /M arrest by inhibiting CDK1 activity and causing apoptosis via ROS-mitochondrial apoptotic pathway in human hepatocarcinoma cells in vitro and in vivo

Abstract

In this study, we reported millepachine (MIL), a novel chalcone compound for the first time isolated from Millettia pachycarpa Benth (Leguminosae), induced cell cycle arrest and apoptosis in human hepatocarcinoma cells in vitro and in vivo. In in vitro screening experiments, MIL showed strong antiproliferation activity in several human cancer cell lines, especially in HepG2 cells with an IC50 of 1.51 µM. Therefore, we chose HepG2 and SK-HEP-1 cells to study MIL's antitumor mechanism. Flow cytometry showed that MIL induced a G2/M arrest and apoptosis in a dose-dependent manner. Western blot demonstrated that MIL-induced G2/M arrest was correlated with the inhibition of cyclin-dependent kinase 1 activity, including a remarkable decrease in cell division cycle (cdc) 2 synthesis, the accumulation of phosphorylated-Thr14 and decrease of phosphorylation at Thr161 of cdc2. This effect was associated with the downregulation of cdc25C and upmodulation of checkpoint kinase 2 in response to DNA damage. MIL also activated caspase 9 and caspase 3, and significantly increased the ratio of Bax/Bcl-2 and stimulated the release of cytochrome c into cytosol, suggesting MIL induced apoptosis via mitochondrial apoptotic pathway. Associated with those effects, MIL also induced the generation of reactive oxygen species. In HepG2 tumor-bearing mice models, MIL remarkably and dose dependently inhibited tumor growth. Treatment of mice with MIL (20mg/kg intravenous [i.v.]) caused more than 65% tumor inhibition without cardiac damage compared with 47.57% tumor reduction by 5mg/kg i.v. doxorubicin with significant cardiac damage. These effects suggested that MIL and its easily modified structural derivative might be a potential lead compound for antitumor drug.

The expression of CDK1 is associated with proliferation and can be a prognostic factor in epithelial ovarian cancer

“…Moreover, in several human cancers, the role of CDK1 has been well characterized. Some researchers observed that in breast, hepatocarcinoma, oral, and lung carcinomas, CDK1 was found to be upregulated and correlated with clinicopathological factors [9,[17][18][19]. Besides, CDK1 is required for the distant metastases of colon cancer [11].…”

Alkaloids from Beach Spider Lily (Hymenocallis littoralis) Induce Apoptosis of HepG-2 Cells by the Fas-signaling Pathway

“…Activation of the CDK1-cyclin B brings the onset of mitosis and is tightly regulated. During G2 phase, CDK1-cyclin B complex is held in an inactive state by phosphorylation of CDK1 at the two negative regulatory sites (Lindqvist et al, 2007;Gavet et al, 2010;Wu et al, 2013). AHL significantly affected the expression of CyclinB1 and CDK1 proteins in HepG-2 cell, CyclinB1 proteins expression level in HepG-2 cells was unregulated upon the treatment of three concentrations of AHL (2.0μg/ml, 4.0μg/ml and 8.0µg/ml respectively) (p<0.01), Whereas, the CDK1 showed unregulated expression upon the treatment of moderate dose (4.0μg/ml ) and high dose (8.0μg/ml ) of AHL (p<0.05).…”

SKLB-M8 Induces Apoptosis Through the AKT/mTOR Signaling Pathway in Melanoma Models and Inhibits Angiogenesis With Decrease of ERK1/2 Phosphorylation

“…Cells (2 × 10 3 -1 × 10 4 cells per well) were seeded in 96-well culture plates overnight for attachment, then treated with vehicle alone or various concentrations of SKLB-M8 for 24 h (HUVECs) or 48 h (melanoma cells), and measured using the MTT assay with a Spectramax M5 Microtiter Plate Luminometer (Molecular Devices) as previously described (11). Each assay performed in triplicate.…”

“…Millepachine (MIL), a novel chalcone with a 2,2-dimethylbenzopyran motif, was first isolated from Millettia pachycarpa Benth (Leguminosae) by our group, which is a flavonoid-rich traditional Chinese medicine, has been used as a blood tonic in antihelminthic and cancer therapy for many years in China. In our previous studies, MIL was reported to be a potential lead compound for antitumor drug development and induced cell cycle arrest and apoptosis in human hepatocarcinoma cells (11). However, the poor solubility of MIL limited its further higher dose treatment.…”