Anti-hepatoma cells function of luteolin through inducing apoptosis and cell cycle arrest

Abstract

The aim of this study is to explore the apoptotic induction and cell cycle arrest function of luteolin on the liver cancer cells and the related mechanism. The liver cancer cell line SMMC-7721, BEL-7402, and normal liver cells HL-7702 were treated with different concentrations of luteolin. Cell proliferation ability was tested. Morphological changes of the apoptotic cells were observed under inverted fluorescence microscope after Hoechst33342 staining. We investigated the effect of luteolin on cell cycling and apoptosis with flow cytometry. The mitochondrial membrane potential changes were analyzed after JC-1 staining. Caspases-3 and Bcl-2 family proteins expression were analyzed by real-time PCR. Cell proliferation of SMMC-7721 and BEL-7402 were inhibited by luteolin, and the inhibition was dose-time-dependent. Luteolin could arrest the cells at G1/S stage, reduce mitochondrial membrane potential, and induce higher apoptosis rate and the typical apoptotic morphological changes of the liver carcinoma cells. Q-RT-PCR results also showed that luteolin increased Bax and caspase-3 expression significantly and upregulated Bcl-2 expression in a dose-dependent manner in liver carcinoma cells. However, the normal liver cells HL-7702 was almost not affected by luteolin treatment. Luteolin can inhibit SMMC-7721 and BEL-7402 cell proliferation in a time- and dose-dependent manner. And the mechanism maybe through arresting cell cycle at phase G1/S, enhancing Bax level, reducing anti-apoptotic protein Bcl-2 level, resulting in activating caspase-3 enzyme and decrease of mitochondrial membrane potential, and finally leading to cell apoptosis.

Luteolin induces apoptosis in vitro through suppressing the MAPK and PI3K signaling pathways in gastric cancer

“…Furthermore, it has been documented that luteolin could arrest the cell cycle and induce apoptosis in a wide variety of cancer cells in vitro , including prostate cancer cells (20), AGS human gastric cancer cells (21,22), SMMC7721 liver cancer cells (23), COLO205 human colorectal cancer cells and HeLa human cervical cancer cells (24). It has also been reported that luteolin was able to significantly decrease colon cancer incidence and the number of tumors per rat when administered at the initiation and post-initiation stages of carcinogenesis (25).…”

Apoptosis Evaluation by Electrochemical Techniques

“…[59,60] Detection methods of caspasee xpression primarily rely on RT-PCR, flow cytometric based analysis, colori-/fluorometric assays,a nd SPR technology. [61][62][63][64] Recently,t ime-resolved FRET technology has been developed to detect caspase-3. [65] Althoughmost of thesemethods are promisingi nthe laboratory, unfortunately,they are usually time consuming, labor intensive, or require highly technical experience and complex instrumentation.…”

Radiosensitization to X-ray radiation by telomerase inhibitor MST-312 in human hepatoma HepG2 cells

“…If apoptosis induced by MST-312 pretreatment and X-ray irradiation is through the mitochondrial pathway, the mitochondrial membrane integrity will be damaged at the early stage of cell apoptosis [7]. The JC-1 fluorescence changes from red to green following the decline of mitochondrial membrane potential.…”