胶质母细胞瘤FGFR3-TACC3融合基因介导丙酮酸激酶M2入核促进DNA损伤修复基础研究

目的探讨胶质母细胞瘤FGFR3-TACC3(F3-T3)融合基因介导丙酮酸激酶M2(PKM2)入核激活DNA损伤修复致替莫唑胺(TMZ)耐药的作用机制。方法慢病毒转染构建稳定表达F3-T3融合基因和空载体的胶质母细胞瘤细胞系U87MG和U251MG,构建稳定表达F3-T3融合基因的胶质母细胞瘤裸鼠模型,小动物活体成像系统观察荷瘤鼠肿瘤荧光信号强度;采用生物信息学分析基因芯片转录组数据分析F3-T3融合基因的生物学功能,并分析肿瘤基因组学图谱计划(TCGA)数据库中胶质瘤患者生存期与PKM2基因表达的关系;瞬时转染小干扰RNA(siRNA)敲低PKM2基因表达;CCK-8细胞增殖实验观察经梯度浓度替莫唑胺处理后、转染siRNA后、替莫唑胺联合PKM2抑制剂Compound 3k处理后U87MG和U251MG细胞增殖活性;提取核质蛋白并观察经替莫唑胺处理后总蛋白提取物、胞质提取物和胞核提取物PKM2蛋白表达情况;Western blotting法检测稳定表达F3-T3融合基因的U87MG和U251MG细胞PKM2蛋白相对表达量、磷酸化组蛋白H2AX(p-H2AX)相对表达量、siRNA敲低PKM2基因p-H2AX相对表达量。结果(1)CCK-8细胞增殖实验显示,经替莫唑胺640、320、160、80、40μmol/L处理后F3-T3转染组的U87MG细胞存活率均高于空载体转染组(P=0.000,0.000,0.000,0.004,0.010),经替莫唑胺640、320、160、80、40、20、5μmol/L处理后F3-T3转染组的U251MG细胞存活率亦均高于空载体转染组(P=0.000,0.000,0.000,0.000,0.002,0.001,0.002);然而,经替莫唑胺640、320、160、80、40、20、10、5和2.50μmol/L处理后si-PKM2-1009转染组的U87MG细胞存活率均低于F3-T3转染组(P=0.000,0.000,0.000,0.012,0.006,0.030,0.000,0.007,0.025),经替莫唑胺640、320、160、80、40、20、5μmol/L处理后si-PKM2-1377转染组U251MG细胞存活率亦低于F3-T3转染组(P=0.000,0.000,0.002,0.000,0.002,0.048,0.042);经替莫唑胺640、320、160、80、40、20μmol/L处理后TMZ+Compound 3k组U87MG细胞存活率低于TMZ组(P=0.000,0.000,0.000,0.000,0.001,0.002),经高浓度(640、320、160、80、40μmol/L)替莫唑胺处理后TMZ+Compound 3k组U251MG细胞存活率亦低于TMZ组(P=0.000,0.000,0.000,0.000,0.003),而经低浓度(10、5、2.50μmol/L)替莫唑胺处理后TMZ+Compound 3k组U251MG细胞存活率高于TMZ组(P=0.000,0.000,0.006)。(2)胶质母细胞瘤动物模型显示,荷瘤鼠存在替莫唑胺耐药。(3)生物信息学分析,F3-T3融合蛋白的生物学功能显著富集于DNA修复通路(P=0.000)。TCGA数据库中胶质瘤患者PKM2基因高表达组生存率和总生存期均低于低表达组(P<0.05)。(4)Western blotting法显示,经替莫唑胺处理48 h再更换培养基后24、36和48 h,F3-T3转染组U87MG(P=0.000,0.000,0.004)和U251MG(P=0.000,0.007,0.005)细胞p-H2AX蛋白相对表达量均低于空载体转染组;经替莫唑胺处理后F3-T3转染组U87MG和U251MG细胞均可见明显的PKM2入核,而空载体转染组细胞均未见这一现象;si-PKM2-1009和si-PKM2-1377分别敲低U87MG(P=0.000,0.001,0.006)和U251MG(P=0.000,0.000,0.000)细胞PKM2基因表达的效果最显著。结论F3-T3融合基因可促进PKM2入核,激活DNA损伤修复相关通路,进而介导胶质母细胞瘤对替莫唑胺耐药,不同细胞株对替莫唑胺的耐药浓度不一致,PKM2抑制剂可逆转这种耐药。

川芎嗪、复方丹参注射液对肺心病血液流变学的影响

研究目的探讨川芎嗪、复方丹参治疗肺心病的机理及疗效。研究背景慢性肺心病病程长、病理过程复杂，有研究认为改善肺心病血液流变学有助于本病的控制。研究方法107例肺心病分为3组：川芎嗪组31例，丹参组35例，联合组（川芎嗪和复方丹参联合静脉滴注）41例。血液流变学检查采用梁氏法。结果川芎嗪、复方丹参注射液对肺心病急性发作期血液流变学有明显改善作用。而川芎嗪在降低全血粘度低切方面优于复方丹参注射液（P＜0.05）。两种药物联合应用在降低全血和血浆粘度及红细胞压积等方面较单用一种药物作用显著（P＜0.01）。结论川芎嗪和复方丹参注射液对肺心病急性发作期血液流变学有明显改善作用，联合应用效果更佳。