低濃度葫蘆素-I誘導胃癌細胞G2/M期阻滯和細胞凋亡及其機制研究

李 建 肖修玲 李 彥 鄒曉平 鄧 超#

重慶市開州區人民醫院消化科1(405400) 南京大學醫學院附屬鼓樓醫院消化科2

低濃度葫蘆素-I誘導胃癌細胞G2/M期阻滯和細胞凋亡及其機制研究

李 建1*肖修玲1李 彥1鄒曉平2鄧 超1#

重慶市開州區人民醫院消化科1(405400)南京大學醫學院附屬鼓樓醫院消化科2

背景：葫蘆素-I通過抑制STAT3信號通路在多種惡性腫瘤中發揮強大的抗癌作用，但其在胃癌中是否同樣具有抗癌作用及其作用機制，目前仍不清楚。目的：通過體外實驗評估低濃度葫蘆素-I對人胃癌細胞增殖、細胞周期和細胞凋亡的影響并初步探討其可能作用機制。方法：以低濃度葫蘆素-I處理人胃腺癌細胞株AGS和HGC-27，采用CCK-8試驗和集落形成試驗評估其對細胞增殖的抑制作用，流式細胞儀檢測細胞周期和細胞凋亡，蛋白質印跡法檢測細胞周期轉換相關蛋白表達以及caspase-3/PARP細胞凋亡途徑、STAT3、GADD45α和JNK/p38 MAPK信號通路激活情況。結果：低濃度葫蘆素-I可在不抑制STAT3信號通路的情況下發揮強大的胃癌細胞生長抑制作用，此作用是通過誘導細胞周期G2/M期阻滯和細胞凋亡實現的。機制研究發現葫蘆素-I可通過上調GADD45α和激活JNK/p38 MAPK信號通路誘導細胞凋亡，發揮抗胃癌作用。結論：本研究揭示了葫蘆素-I抗胃癌作用的新機制，證明葫蘆素-I是一個具有臨床應用前景的化療藥物。

葫蘆素類； STAT3轉錄因子； 生長阻滯和DNA損傷誘導蛋白45α； 絲裂原活化蛋白激酶類； 胃腫瘤； 細胞周期； 細胞凋亡

Correspondenceto: DENG Chao, Email: denchao1@126.com

Background: Upon inhibition of STAT3 signaling pathway, cucurbitacin-I elicits anticancer effect in various malignancies. However, the anticancer effect and underlying mechanism of cucurbitacin-I in gastric cancer is still elusive.Aims: To explore the effect of low nanomolar cucurbitacin-I on cell proliferation, cell cycle and apoptosis in human gastric cancer cells and the underlying mechanisminvitro.Methods: Human gastric adenocarcinoma cell lines AGS and HGC-27 were treated with cucurbitacin-I at low nanomolar concentration. The anti-proliferative effect of cucurbitacin-I was detected by CCK-8 assay and colony formation assay. Flow cytometry was used to assess the cell cycle and apoptosis.Expressions of cell cycle-related proteins, as well as activation of related pathways such as caspase-3/PARP apoptotic pathway, STAT3, GADD45α and JNK/p38 MAPK signaling pathways were determined by Western blotting.Results: Cucurbitacin-I markedly inhibited the growth of gastric cancer cells at low nanomolar concentration by inducing G2/M phase arrest and apoptosis via a STAT3-independent manner. Furthermore, it was revealed that the anticancer effect of cucurbitacin-I was associated with up-regulation of GADD45α, activation of JNK/p38 MAPK signaling pathway and the subsequent apoptotic events.Conclusions: The present study provides new insights into the mechanism of anticancer effect of cucurbitacin-I, supporting cucurbitacin-I as an attractive therapeutic drug in gastric cancer.

KeywordsCucurbitacins; STAT3 Transcription Factor; Growth Arrest and DNA Damage-Inducible Protein 45alpha; Mitogen-Activated Protein Kinases; Stomach Neoplasms; Cell Cycle; Apoptosis

葫蘆素是一類來源于葫蘆科植物的三萜類化合物，具有抗菌、抗炎、抗糖尿病等多種生物學活性[1]。……