[Effects of Astragalin on apoptosis of undifferentiated gastric cancer cells].

OBJECTIVE: To investigate the effects and related molecular mechanisms of Astragalin on undifferentiated gastric cancer cell HGC-27. METHODS: Astragalin was used to treat HGC-27 cells, the cell proliferation activity was detected by CCK-8 method, the cell morphology was observed under inverted microscope, hoechst 33342 and JC-1 staining were used to observe the changes of nucleus formation and mitochondrial membrane potential, the cell cycle and apoptosis rate were detected by flow cytometry, the reverse transcription level of the gene was analyzed by the second-generation sequencer. RESULTS: Astragalin inhibited the proliferation of HGC-27 significantly (P＜0.01), down-regulated mitochondrial membrane potential, induced cell apoptosis, blocked the cell cycle in G1 prophase. At the same time, Astragalin up-regulated the transcription levels of genes bax and bad, down-regulated the transcription levels of genes egf, egfr, pik3cb, pdk1, akt3 and bcl-2. Western blot analysis also showed that the expressions of PI3K and Akt protein were decreased, and the proportion of Bax and BCL-2 protein was increased significantly (P＜0.01). CONCLUSION: The apoptosis of undifferentiated gastric cancer cell line HGC-27 can be induced by Astragalin through inhibition of EGFR/PDK/Akt signaling pathway, and the cell cycle can be blocked in G1 phase, which has a certain therapeutic effect on undifferentiated gastric cancer.

[Anti-gastric cancer effects of Z Ajoene and its molecular mechanisms].

Objective: To investigate the effects of Z Ajoene on gastric cancer cell MGC-803 and its molecular mechanisms. Methods: The gastric cancer cells MGC-803 were treated with 0, 1, 5, 25 and 125 µmol/L Z Ajoene for 24 h, 48 h and 72 h, each with 3 replicate wells. The proliferation activity of MGC-803 cells was analyzed by MTS method, mitochondrial membrane potential was analyzed after JC-1 staining, nuclear type was observed after Hoechst 33342 staining, cytotoxicity was detected by LDH release method, and the apoptosis level and cell cycle were analyzed with flow cytometry. RT-qPCR and Western blot methods were used to evaluate the expression levels of P53, Caspase-3, RAS, ERK, BCL-2, AKT, mTOR and PI3K genes. At the same time, 4-week-old male BALB/C mice were randomly divided into 5 groups, 20 per group, and were subcutaneously inoculated with gastric cancer cell MGC-803 in the groin. Two days later, each group was injected with Z Ajoene at the doses of 0, 1, 5, 25 and 125 µmol/L, 0.1 ml/time, and was injected every other day. On the 20th day of the first injection of tumor cells, 10 mice in each group were killed, the tumor tissues were taken out and weighed. The survival period of the remaining mice was recorded and the effects of Z Ajoene on the growth and survival period of gastric cancer in tumor-bearing mice were observed. Results: After Z Ajoene treatment, the proliferation activity of MGC-803 cells was significantly inhibited and the apoptosis rate was significantly increased(P＜0.01). The transcription and expression levels of p53, Caspase-3 and BAX genes were significantly increased, while the transcription and expression levels of RAS, ERK1, BCL-2, AKT, mTOR and PI3K genes were decreased markedly(P＜0.01). The tumor inhibition experiments showed that the growth of the tumor could be inhibited and the survival time of the tumor-bearing animals could be greatly prolonged after Z Ajoene treatment(P＜0.01). Conclusion: Z Ajoene has therapeutic effects on gastric cancer, can inhibit the proliferation of gastric cancer cells and induce them apoptosis by regulating the expression of PI3K-AKT-mTOR and RAS-RAF-MEK-ERK signal pathways.

Quantitative assessment of the impacts of climate change and human activities on runoff change in a typical karst watershed, SW China.

The Yinjiang River watershed is a typical karst watershed in Southwest China. The present study explored runoff change and its responses to different driving factors in the Yinjiang River watershed over the period of 1984 to 2015. The methods of cumulative anomaly, continuous wavelet analysis, Mann-Kendall rank correlation trend test, and Hurst exponent were applied to analyze the impacts of climate change and human activities on runoff change. The contributions of climate change and human activities to runoff change were quantitatively assessed using the comparative method of the slope changing ratio of cumulative quantity (SCRCQ). The following results were obtained: (1) From 1984 to 2015, runoff and precipitation exhibited no-significant increasing trend, whereas evaporation exhibited significant decreasing trend. (2) In the future, runoff, precipitation, and evaporation will exhibit weak anti-persistent feature with different persistent times. This feature indicated that in their persistent times, runoff and precipitation will continuously decline, whereas evaporation will continuously increase. (3) Runoff and precipitation were well-synchronized with abrupt change features and stage characteristics, and exhibited consistent multi-timescale characteristics that were different from that of evaporation. (4) The contribution of precipitation to runoff change was 50%-60% and was considered high and stable. The contribution of evaporation to runoff change was 10%-90% and was variable with a positive or negative effects. The contribution of human activities to runoff change was 20%-60% and exerted a low positive or negative effect. (5) Climatic factors highly contributed to runoff change. By contrast, the contribution of human activities to runoff change was low. The contribution of climatic factors to runoff change was highly variable because of differences among base periods. In conclusion, this paper provides a basic theoretical understanding of the main factors that contribute to runoff change in a karst watershed.