目的观察化痰消瘀方对胃癌前病变大鼠PTEN、FAK及paxillin表达的影响,从分子生物学水平探讨其逆转胃癌前病变的作用机制。方法选择90只4~5周龄SD雄性大鼠,随机取15只作为空白组,其余大鼠均采用N-甲基-N’-硝基N-亚硝基胍综合饥饱失常、...目的观察化痰消瘀方对胃癌前病变大鼠PTEN、FAK及paxillin表达的影响,从分子生物学水平探讨其逆转胃癌前病变的作用机制。方法选择90只4~5周龄SD雄性大鼠,随机取15只作为空白组,其余大鼠均采用N-甲基-N’-硝基N-亚硝基胍综合饥饱失常、浓盐水灌胃的方法制备胃癌前病变大鼠模型。将造模成功大鼠随机分为模型组,中药高、中、低剂量组及维酶素组,每组13只。空白组正常饮食,余均造模成功后,模型组给予生理盐水灌胃,中药高、中、低剂量组分别给予3 m L/kg、2 m L/kg、1 m L/kg化痰消瘀方灌胃,维酶素组给予10 m L/kg维酶素灌胃,均灌胃8周。采用HE染色法观察大鼠胃黏膜病理改变情况,应用免疫组化法检测胃黏膜组织中PTEN、FAK及paxillin的表达情况。结果 HE染色显示空白组大鼠胃黏膜无癌前病变改变,模型组均出现不同程度的胃癌前病变改变,中药高、中剂量组和维酶素组胃黏膜癌前病变情况均较模型组明显改善（P均〈0.05）,且中药高剂量组改善程度高于其他各给药组（P均〈0.05）。免疫组化结果显示PTEN在空白组强阳性表达;模型组鲜有表达;中药高、中、低剂量组表达量逐渐降低,但高于模型组（P均〈0.05）;中药高剂量组PTEN表达量高于其他各给药组（P均〈0.05）。FAK、paxillin在空白组极少表达,模型组表达量较空白组显著增加（P均〈0.05）;中药高、中、低剂量组二者表达量均明显低于模型组（P均〈0.05）,其中高剂量组表达量明显低于其他各给药组（P均〈0.05）。结论中药化痰消瘀方可显著改善胃癌前病变大鼠胃黏膜组织病理学情况,其作用机制可能是激活抑癌基因PTEN,调节FAK的去磷酸化,通过FAK/Src信号通路下调paxillin来诱导细胞凋亡。展开更多
Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B(Cuc B) is a natural triterpenoid with potent anticancer activ...Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B(Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B(< 100 nmol·L~^(-1)) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase(FAK) and paxillin in dose-and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species(ROS) generation, which could be reduced by N-acetyl-l-cysteine(NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.展开更多
文摘目的观察化痰消瘀方对胃癌前病变大鼠PTEN、FAK及paxillin表达的影响,从分子生物学水平探讨其逆转胃癌前病变的作用机制。方法选择90只4~5周龄SD雄性大鼠,随机取15只作为空白组,其余大鼠均采用N-甲基-N’-硝基N-亚硝基胍综合饥饱失常、浓盐水灌胃的方法制备胃癌前病变大鼠模型。将造模成功大鼠随机分为模型组,中药高、中、低剂量组及维酶素组,每组13只。空白组正常饮食,余均造模成功后,模型组给予生理盐水灌胃,中药高、中、低剂量组分别给予3 m L/kg、2 m L/kg、1 m L/kg化痰消瘀方灌胃,维酶素组给予10 m L/kg维酶素灌胃,均灌胃8周。采用HE染色法观察大鼠胃黏膜病理改变情况,应用免疫组化法检测胃黏膜组织中PTEN、FAK及paxillin的表达情况。结果 HE染色显示空白组大鼠胃黏膜无癌前病变改变,模型组均出现不同程度的胃癌前病变改变,中药高、中剂量组和维酶素组胃黏膜癌前病变情况均较模型组明显改善（P均〈0.05）,且中药高剂量组改善程度高于其他各给药组（P均〈0.05）。免疫组化结果显示PTEN在空白组强阳性表达;模型组鲜有表达;中药高、中、低剂量组表达量逐渐降低,但高于模型组（P均〈0.05）;中药高剂量组PTEN表达量高于其他各给药组（P均〈0.05）。FAK、paxillin在空白组极少表达,模型组表达量较空白组显著增加（P均〈0.05）;中药高、中、低剂量组二者表达量均明显低于模型组（P均〈0.05）,其中高剂量组表达量明显低于其他各给药组（P均〈0.05）。结论中药化痰消瘀方可显著改善胃癌前病变大鼠胃黏膜组织病理学情况,其作用机制可能是激活抑癌基因PTEN,调节FAK的去磷酸化,通过FAK/Src信号通路下调paxillin来诱导细胞凋亡。
基金supported by the Science and Technology Development Fund,Macao S.A.R(FDCT)(No.039/2014/A1)the Research Fund of University of Macao(Nos.CPG2014-00012-ICMS,MYRG2016-00043-ICMS-QRCM,and MYRG2015-00091-ICMS-QRCM)
文摘Metastasis is responsible for the majority of cancer-related deaths and prevention of metastasis remains a big challenge for cancer therapy. Cucurbitacin B(Cuc B) is a natural triterpenoid with potent anticancer activities while its effect on metastasis remains unclear. In the present study, the inhibitory effect and mechanisms of Cuc B on metastasis were investigated in MDA-MB-231 breast cancer cells. The cells were treated with or without Cuc B, and the cytotoxicity was determined by MTT assay. The effect of Cuc B on metastasis was evaluated with wound healing, transwell, and adhesion assays. Furthermore, the adhesion of cancer cells to endothelial cells was determined. The protein expression was determined by Western blotting. Cuc B(< 100 nmol·L~^(-1)) showed no obvious cytotoxicity to MDA-MB-231 cells, but significantly inhibited migration, invasion, and adhesion to Matrigel, fibronectin, type I collagen, and endothelial cells. Cuc B dramatically inhibited the phosphorylation of focal adhesion kinase(FAK) and paxillin in dose-and time-dependent manners. Furthermore, Cuc B induced intracellular reactive oxygen species(ROS) generation, which could be reduced by N-acetyl-l-cysteine(NAC). In addition, NAC pretreatment could reverse Cuc B-induced suppression of migration and adhesion, expression of FAK, but showed no effect on paxillin expression. In summary, Cuc B suppressed ROS-dependent metastasis through FAK pathway in breast cancer MDA-MB-231 cells, demonstrating novel mechanisms for the anticancer effects of Cuc B.
