目的 研究竹叶提取物抑制肿瘤细胞增殖的活性及其分子生物学机制。方法 选取血管内皮生长因子(VEGF)诱导型肿瘤细胞人肝癌细胞HepG2和不诱导型肿瘤细胞人神经母细胞瘤细胞SH-SY5Y为模型,用不同质量浓度竹叶提取物处理HepG2和SH-SY5Y细胞。采用MTT法检测竹叶提取物对2种细胞增殖的抑制作用;采用RT-PCR法检测VEGF和血管内皮生长因子受体2(VEGFR2)基因在HepG2和SH-SY5Y细胞中的表达差异以及竹叶提取物处理后HepG2细胞中VEGF基因表达的变化;用荧光倒置显微镜观察竹叶提取物处理后SH-SY5Y细胞神经突触的生长情况;采用RT-PCR法检测竹叶提取物处理后SH-SY5Y细胞中神经生长因子(NGF)表达的变化。结果 竹叶提取物对HepG2细胞增殖的抑制活性高于对SH-SY5Y细胞的增殖抑制作用。进一步研究发现HepG2细胞中VEGF和VEGFR2基因的表达显著高于SH-SY5Y细胞,且竹叶提取物可显著抑制HepG2细胞的VEGF表达。适当剂量的竹叶提取物可以刺激SH-SY5Y细胞神经突触的生长,并可上调其NGF的表达。结论 竹叶提取物可能通过抑制VEGF的表达影响VEGF诱导型肿瘤细胞的增殖,同时,可能通过上调NGF的表达刺激神经细胞神经突触的生长,竹叶提取物可能具有潜在的抗肿瘤和神经保护的双重功效。

Objective In this study, we selected two types of tumor cell lines, HepG2 (VEGF-dependent) and SH-SY5Y (VEGF- independent) to investigate the anti-tumor activity of flavones extract from bamboo leaf (bamboo-leaf flavones) and their molecular mechanism. Methods The bamboo-leaf flavones were used to treat HepG2 and SH-SY5Y cells. The activity of bamboo-leaf flavones in inhibition of the proliferation of HepG2 and SH-SY5Y cells was determined by MTT method. Gene expression of VEGF and VEGFR2 in HepG2 and SH-SY5Y cells was determined by RT-PCR method, so did gene expression of VEGF in HepG2 cells and NGF in SH-SY5Y cells after cells treated by bamboo-leaf flavones. Outgrowth of neurite in SH-SY5Y cells after treated by bamboo-leaf flavones was investigated by inverted fluorescence microscope. Results Data showed that bamboo-leaf flavones had a significantly higher inhibition to the proliferation of HepG2 cells than that of SH-SY5Y cells. We further observed that HepG2 cells expressed higher levels of VEGF and VEGFR2 cells than those of SH-SY5Y cells and bamboo-leaf flavones down-regulated VEGF expression in HepG2 cells. In addition, we also found bamboo-leaf flavones stimulate the neurite outgrowth in SH-SY5Ycells and up-regulated their NGF expression. Conclusion Bamboo-leaf flavones could inhibit the proliferation of VEGF-dependent tumor cells by the probable down-regulation of VEGF expression. Meanwhile, bamboo-leaf flavones could stimulate the neurite outgrowth of neurons by the probable up-regulation of the NGF expression. Therefore, bamboo-leaf flavones probably have the dual functions in anti-tumor and neuroprotection.

浙江农林大学科研发展基金(2012FR017);浙江省自然科学基金资助项目(LQ14H280007)