p38MAPK在肝细胞癌中的研究进展

Diosgenin regulates proliferation, apoptosis, migration and invasion of human esophageal cancer Eca109 cells via the MAPK signaling pathway

AIM: To investigate the effects of diosgenin on the proliferation, apoptosis, migration and invasion of human esophageal Eca109 cells and to explore the underlying mechanisms.

METHODS: MTT and transwell experiments were executed to detect the effects of diosgenin on the proliferation, migration and invasion of Eca109 cells. Western blot was applied to detect the expression of c-Jun N-terminal of stress-activated protein kinase (JNK), extracellular signal-regulated kinase (Erk1/2) and the p38 kinase of the mitogen-activated protein kinase (MAPK) pathway.

RESULTS: Compared with the control group, Eca109 cells treated with 50 μg/mL of diosgenin for 48 h showed significantly decreased proliferation, migration (16.54 vs 34.12, P < 0.05) and invasion (9.42 vs 26.99, P < 0.05) but increased apoptosis (0.24 vs 0.64, P < 0.05). Moreover, diosgenin treatment significantly decreased the expression of p-p38 protein (1.66 vs 0.23, P < 0.05) but had no significant effect on the expression of JNK, Erk1/2, p38, p-JNK, or p-Erk1/2.

CONCLUSION: Diosgenin regulates the proliferation, apoptosis, migration and invasion of Eca109 cells possibly via the p-p38 pathway.

LPS regulates epithelial-mesenchymal transition in cholangiocarcinoma cell line ICBD via the p38/MAPK signaling pathway

AIM: To investigate the effect of LPS on epithelial-mesenchymal transition (EMT) of cholangiocarcinoma ICBD cells and to explore the possible mechanisms involved.

METHODS: ICBD cells were randomly divided into four groups: a control group, a LPS (final concentration, 10 μg/mL) group, a LPS + siRNA group, and a LPS + SB203580 group. The expression of epithelial cell surface marker E-Cadherin, stromal cell surface marker Vimentin, TLR4 and p38 was examined by real-time RT-PCR and Western blot.

RESULTS: LPS promoted the initiation of EMT of ICBD cells. The expression of TLR4 and p38 significantly increased in the process of EMT of ICBD cells. SiRNA-mediated blockage of TLR4 inhibited the occurrence of EMT and the up-regulation of p38 in ICBD cells. When p38 was blocked by SB-203580, the expression of TLR4 was still up-regulated, but EMT of ICBD cells did not occur compared to the control group.

CONCLUSION: LPS may activate TLR4 and promote EMT of cholangiocarcinoma cells via the p38/MAPK signaling pathway.

Mechanisms underlying suppressive effect of lutein on cell proliferation in human colon cancer cell line HT29

AIM: To study the anti-proliferative effect of lutein on human colon cancer HT29 cells and to explore the possible mechanisms involved.

METHODS: HT29 cells were treated with different concentrations of lutein (20, 40, 80, 160 mg/L) for 24, 48 or 72 h. After treatment, cell proliferation was detected by SRB assay, cell cycle progression was analyzed by flow cytometry, cell apoptosis was detected by fluorescence microscopy and Hoechst 33342/PI staining, and the levels of p-ERK and p-p38 proteins were determined by Western blot.

RESULTS: Lutein treatment inhibited the proliferation of HT29 cells in a dose- and time-dependent manner. After treatment of HT29 cells with lutein (80 mg/L) for 48 h, the percentage of cells at G₀/G₁ phase cells increased from 58.67% to 63.23%, and with the increase in drug concentration, the percentage of cells at G₀/G₁ phase increased significantly. When the lutein concentration was 160 mg/L, the percentage of cells at G₀/G₁ phase increased to 70.81%, indicating that lutein arrested HT29 cells in G₀/G₁ phase. Fluorescence microscopy and Hoechst 33342/PI staining suggested that lutein induced HT29 cell apoptosis in a dose-dependent manner. Western blot analysis showed that lutein down-regulated the expression of p-ERK and up-regulated the expression of p-p38 protein in dose-dependent manner (both P < 0.01).

CONCLUSION: Lutein could significantly inhibit the proliferation of HT29 cells, induce apoptosis, and arrest cell cycle in G0/G1 phase. Down-regulation of p-ERK protein expression and up-regulation of p-p38 protein expression may be important mechanisms responsible for the apoptosis-inducing effect of lutein.

P38 MAPK signaling pathway: biological functions, roles in the pathogenesis of liver fibrosis and common research methods

The activation and proliferation of hepatic stellate cells (HSC) are the key events in hepatic fibrogenesis. Now the research about the mechanisms of action of HSC-related signal transduction has become a hot topic. This article reviews the biological functions of the p38 MAPK signaling pathway and its roles in the pathogenesis of liver fibrosis and summarizes common research methods for this signaling pathway.