罗汉松实提取物对鼻咽癌CNE-2R移植瘤生长和放射敏感性的影响

Effects of Semen Podocarpi Extract on Growth and Radiosensitivity of Nasopharyngeal Carcinoma CNE-2R Transplanted Tumor

目的:研究罗汉松实提取物(SPE)对鼻咽癌CNE-2R移植瘤生长和放射敏感性的影响,并探讨其潜在的作用机制。方法:荷瘤裸鼠分为模型组、SPE组(60 mg/kg)、照射组、SPE+照射组,另取正常裸鼠设为空白组。SPE组和SPE+照射组灌胃给予SPE药液,其余各组给予生理盐水10 mL/kg,1次/d,连续7 d。末次给药后6 h,照射组和SPE+照射组以2 Gy X线照射,1次/d,连续3d,SPE+照射组同时给予SPE,至照射后第4天停止给药。各组动物取血,取肿瘤组织,称质量,计算抑瘤率;HE染色法观察肿瘤组织切片病理学变化;ELISA法测定血清中IL-2、TNF-α和IFN-γ含量;RT-PCR和Western Blot法分别检测肿瘤组织中C-Raf、MEK、ERK1、ERK2 mRNA和蛋白的表达。结果:SPE、照射和SPE+照射能显著抑制肿瘤生长,抑瘤率分别为42.37%、66.89%和78.38%,且SPE+照射的作用强于单纯照射;各组肿瘤细胞大量坏死。与模型组比较,SPE和SPE+照射组IL-2和TNF-α含量显著增加(P<0.05);SPE组IFN-γ含量也显著增加(P<0.05)。RT-PCR结果显示,照射和SPE+照射组C-Raf、ERK1和ERK2 mRNA显著降低,且SPE+照射对C-Raf和ERK2表达的抑制作用强于单纯照射(P<0.05)。WB结果显示,SPE、照射和SPE+照射C-Raf、MEK、ERK1和ERK2蛋白表达水平显著降低,且SPE+照射的作用强于单纯照射(P<0.05)。结论:SPE能抑制鼻咽癌CNE-2R移植瘤的生长,并提高肿瘤组织对射线的敏感性。其机制可能与促进IL-2和TNF-α释放,调节免疫功能,下调Raf/MEK/ERK信号通路C-Raf和ERK2 mRNA和蛋白表达有关。

Objective:To study the effects of Semen Podocarpi extract(SPE)on the growth and radiosensitivity of nasopharyngeal carcinoma CNE-2R transplanted tumor,and to explore the underlying mechanism.Methods:Tumor bearing nude mice were divided into model,SPE(60 mg/kg),irradiation,and SPE+irradiation groups,and blank control group was also set.The SPE and SPE+irradiation groups were given SPE solution intragastric administration,and the remaining groups were given normal saline with 10 mL/kg once a day for 7 days.6 hours after the last administration,the irradiation and SPE+irradiation groups were irradiated with 2 Gy of X-rays once a day for 3 days.The SPE+irradiation group was also given SPE,and the administration was stopped on the 4th day after irradiation.Collected blood and tumor tissue.Weighed the tumor and calculated tumor inhibition rate.HE staining was used to observe the pathological changes of tumor tissue.The levels of IL-2,TNF-α,and IFN-γin serum were determined by ELISA method.RT-PCR and Western Blot were used to detect the mRNA and protein expression of C-Raf,MEK,ERK1,and ERK2 of tumor tissues,respectively.Results:SPE,irradiation,and SPE+irradiation significantly inhibit tumor growth,with inhibition rates of 42.37%,66.89%,and 78.38%,respectively,and the effect of SPE+irradiation is stronger than that of simple irradiation.Necrosis of tumor cells was abundant in each group.Compared with the model group,the levels of IL-2 and TNF-αof the SPE and SPE+irradiation groups increased significantly(P<0.05),and the level of IFN-γof the SPE group was also increased(P<0.05).The RT-PCR results showed that the mRNA levels of C-Raf,ERK1,and ERK2 were significantly reduced in the irradiation and SPE+irradiation groups,and SPE+irradiation showed a stronger inhibitory effect on the expression of C-Raf and ERK2 than simple irradiation(P<0.05).The WB results showed that the protein expression levels of C-Raf,MEK,ERK1,and ERK2 were significantly reduced in the SPE,irradiation,and SPE+irradiation groups,and the effect of SPE+irradiation was stronger than that of simple irradiation(P<0.05).Conclusion:SPE inhibit the growth of nasopharyngeal carcinoma CNE-2R transplanted tumor,and enhance the sensitivity of tumor tissue to radiation.The underlying mechanism is to promote the release of IL-2 and TNF-α,regulate immune function,and downregulate the C-Raf and ERK2 mRNA and protein expression of Raf/MEK/ERK signaling pathway.