黑灵芝多糖对小鼠结肠癌细胞内cAMP/PKA信号通路的作用  

Effect of Ganoderma atrum Polysaccharide on cAMP/PKA Pathway in Mouse Colon Cancer Cells

作　　者：张莘莘[1] 聂少平[1] 谢明勇[1] 

机构地区：[1]南昌大学食品科学与技术国家重点实验室,江西南昌330047

出　　处：《食品科学》2013年第23期271-275,共5页Food Science

基　　金：国家自然科学基金项目(31071532;31130041);"十二五"国家科技支撑计划项目(2012BAD33B06);食品科学与技术国家重点实验室目标导向项目(SKLF-MB-201001)

摘　　要：研究黑灵芝多糖(PSG-1)对结肠癌细胞内环磷酸腺苷(cAMP)/蛋白激酶A(PKA)信号途径的影响。实验设5组:空白对照组,50、100、200μg/mL PSG-1组,5-氟尿嘧啶(5-Fu)阳性对照组。采用流式细胞术检测细胞的凋亡,用IBL试剂盒检测胞内cAMP的浓度、PKA的活性,半定量RT-PCR法分析cAMP和PKA的mRNA表达变化。结果表明:PSG-1能诱导CT26细胞凋亡;PSG-1显著提高细胞内cAMP的浓度,3种质量浓度PSG-1作用后cAMP浓度分别比空白对照组升高了20.18%、38.67%和56.25%(P<0.05);与空白对照组相比,PSG-1各组细胞的PKA活性分别上升了15.42%、18.76%和38.26%(P<0.05)。另外,PSG-1组胞内的PKA和CREB mRNA的表达量比空白对照组也明显增加。结果显示,PSG-1能够引起胞内cAMP浓度升高、PKA活性增强,从而激活小鼠结肠癌细胞内cAMP/PKA信号途径。Ganoderma atrum polysaccharide-1 （PSG-1） has been reported to be natural chemopreventive in several types of tumor cells. In our previous study, we found that PSG-1 could significantly inhibit the tumor growth. We hypothesized that PSG-1 might exert its anticancer effect by activating cAMP/protein kinase A （PKA） pathway. The present study was designed to analyze the effect of PSG-1 on the cAMP/PKA pathway in mouse colon cancer CT26 cells. The ceils were treated with 0, 50, 100 μg/mL, and 200 μg/mL PSG-1 or 20 μg/mL 5-fluorouracil, respectively, for 48 h. The ratio of apoptotic CT26 cells was measured by flow cytometry analysis. The cellular cAMP content was tested using a cAMP assay kit. The activity of PKA was measured using a PKA activity assay kit. Reverse transcript-polymerase chain reaction （RT-PCR） was used to analyze the mRNA expressions of PKA and cAMP response element binding protein （CREB） of the Cells. The results showed that PSG-1 significantly induced the apoptosis of the CT26 cells and that cAMP concentration in the cells treated with PSG-1 was dramatically increased by 20.18%, 38.67% and 56.25% （P 〈 0.05）, respectively. The PICA activity was increased by 15.42%, 18.76% and 38.26%, respectively. The mRNA levels of both PKA and CREB of the cells treated with PSG-1 were increased. The current study suggests that PSG-1 activates the cAMP/PKA pathway in colon cancer cells by inducing cAMP production and activating PKA protein.

关 键 词：黑灵芝多糖 CT26细胞 CAMP PKA通路 

分 类 号：Q949.32[生物学—植物学]