Volume 29, Issue 4, 2020
DOI: 10.24205/03276716.2020.853
Effects of Matrine on Autophagy of Esophageal Cancer Ec109 Cells and the Mechanism
Abstract
Objective: To explore the mechanism of action of matrine for the autophagy of esophageal cancer Ec109 cells.
Methods: Esophageal cancer Ec109 cells were cultured in vitro and treated with matrine at different concentrations, and the cell morphological changes were observed under an inverted phase-contrast microscope. The inhibition rate of cell proliferation was detected using methyl thiazolyl tetrazolium assay. The expressions of light chain 3-II (LC3-II) and phosphatidylinositol 3-hydroxy kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway-related proteins p-mTOR, p-Akt and p-p70 ribosomal S6 kinase (p70S6K) were determined using Western blotting. The mRNA expression of autophagy-related gene Beclin1 was detected by real-time quantitative polymerase chain reaction (RT-qPCR).
Results: It was observed under the inverted fluorescence microscope that after treatment with 0.8 g/L matrine, the cells grew slowly and had irregular shape, and the vacuoles were different in size, leading to the increase in cell volume. After treatment with 1.2 g/L matrine, cytoplasmic vacuolation and cellular swelling were observed, but the cell membrane was intact. When the concentration of matrine reached 1.6 g/L, cellular atrophy became worse, cell debris and suspension cells were significantly increased, and autophagic vacuoles could be seen through acridine orange staining. On the contrary, untreated Ec109 cells were in a long shuttle or cobblestone-like shape with irregular nuclei, and karyopyknosis was rare. In the treatment with matrine at different concentrations for 48 h, the inhibition rate of cell proliferation gradually rose with the increase of matrine concentration (P<0.05). Western blotting showed that with rising matrine concentration, the protein expression of LC3-II rose, while those of p-mTOR, p-Akt and p-p70S6K declined. RT-qPCR exhbited that the mRNA expression of Beclin1 was up-regulated by matrine.
Conclusion: Matrine can induce the autophagy of esophageal cancer Ec109 cells, thereby inhibiting their proliferation. The autophagy process may be mediated via the PI3K/Akt/mTOR signaling pathway.
Keywords
matrine; esophageal cancer; PI3K/Akt/mTOR signaling pathway; autophagy