hTERT基因反义核酸对顺铂诱导Jurkat细胞凋亡的影响

目的:用人类端粒酶逆转录酶(hTERT)基因的反义寡核苷酸(ASODN)抑制Jurkat细胞端粒酶活性后, 观察化疗药物(顺铂、柔红霉素、长春新碱、足叶乙甙)对Jurkat细胞凋亡的影响。方法:采用台盼蓝拒染法观察hTERT ASODN与化疗药物(顺铂、柔红霉素、长春新碱、足叶乙甙)联合作用对Jurkat细胞系生长的影响;姬姆萨染色法观察凋亡细胞的形态变化;琼脂糖凝胶电泳分析细胞凋亡的DNA断裂情况;通过流式细胞仪对细胞凋亡峰进行定量分析。结果: hTERT ASODN作用于Jurkat细胞24 h再加入柔红霉素、长春新碱、足叶乙甙, 对细胞生长的抑制分别与单用柔红霉素、长春新碱、足叶乙甙及hTERT正义寡核苷酸(sense oligodeoxynucleotide, SODN)联合柔红霉素、长春新碱、足叶乙甙组相比, 无显著差异(P>0.05) 。hTERT ASODN作用于Jurkat细胞24 h再加入顺铂, 分别与SODN联合顺铂作用组、单用顺铂作用组相比, 对细胞抑制明显增强(P<0.05)。hTERT ASODN作用于Jurkat细胞24 h再加入顺铂作用48 h, 细胞出现典型的凋亡形态学改变, 经琼脂糖凝胶电泳即可见到DNA梯形条带, 而SODN与顺铂联合作用组及单独应用顺铂均未见到DNA梯形条带。hTERT ASODN与2.5 μmol/L顺铂联合作用于Jurkat细胞48h的凋亡细胞百分率(25.18±3.63)%分别同SODN与顺铂联合作用组(10.07±2.12)%、单用顺铂作用组(9.73±2.43)%进行比较有显著差异(P<0.01)。 结论:hTERT基因反义寡核苷酸能促进顺铂诱导Jurkat细胞凋亡。     

抗人DR5单克隆抗体——mDRA-6与顺铂协同杀伤白血病细胞HL-60作用研究

目的：观察抗死亡受体5（Death receptor 5,DR5）单克隆抗体--mDRA-6与顺铂（DDP）对HL-60细胞的协同杀伤作用.方法：DR5蛋白免疫BALB/c小鼠,融合筛选抗DR5杂交瘤细胞,制备抗DR5单抗--mDRA-6;流式细胞术测定顺铂对HL-60细胞表面DR5表达及细胞凋亡率;荧光显微镜下观察mDRA-6与顺铂协同作用下HL-60细胞形态变化;MTT法测定不同浓度的顺铂与mDRA-6对HL-60细胞存活的影响;琼脂糖凝胶电泳检测mDRA-6与顺铂联合对HL-60细胞DNA片段化的影响.结果：顺铂可诱导HL-60细胞表面DR5表达增加,mDRA-6与顺铂联用致HL-60细胞出现染色质浓缩、断裂,细胞出芽,凋亡小体形成等细胞凋亡形态学变化;250 ng/ml的mDRA-6作用于HL-60细胞10小时,细胞凋亡率为16.61%;0.16 μg/ml的DDP作用于HL-60细胞10小时,细胞凋亡率为2.35%;二者联合作用后,HL-60细胞凋亡率增至57.10%;mDRA-6与DDP联合作用HL-60细胞,DNA琼脂糖凝胶电泳显示明显“梯形”条带.结论：抗DR5单抗--mDRA-6与DDP对HL-60细胞具有强大的协同杀伤作用.     

hTERT基因反义核酸对化疗药物诱导CEM细胞凋亡的影响

目的：利用人类端粒酶逆转录酶(hTERT)基因的反义寡核苷酸(ASODN)抑制人T淋巴细胞白血病细胞株(CEM)端粒酶活性后，探讨化疗药物(顺铂、柔红霉素、长春新碱、足叶乙甙)对CEM细胞凋亡的影响。方法： 采用台盼蓝拒染法观察hTERT ASODN与化疗药物(顺铂、柔红霉素、长春新碱、足叶乙甙)联合作用对CEM细胞系生长的影响；姬姆萨染色法观察凋亡细胞的形态变化；通过流式细胞仪对细胞凋亡峰进行定量分析。结果： hTERT ASODN作用于CEM细胞24 h再加入柔红霉素、长春新碱、足叶乙甙，对细胞生长的抑制分别与单用柔红霉素、长春新碱、足叶乙甙及hTERT正义寡核苷酸(SODN)联合柔红霉素、长春新碱、足叶乙甙组相比，统计学上无显著差异(P＞0.05)。hTERT反义核酸作用于CEM细胞24 h加入顺铂，再共同作用48 h，CEM活细胞均数为2.318×108 cells/L，与单用顺铂组(3.250×108 cells/L)及hTERT正义核酸联用顺铂组(3.175×108 cells/L)相比，对细胞抑制明显增强(P＜0.05)。hTERT ASODN作用于CEM细胞24 h再加入顺铂作用48 h，细胞出现典型的凋亡形态学改变。hTERT ASODN与2.5 μmol/L顺铂联合作用于CEM细胞48 h的凋亡细胞百分率(19.47%)分别同SODN与顺铂联合作用组(6.97%)、单用顺铂作用组(6.02%)进行比较有显著差异(P＜0.01)。结论： hTERT基因反义寡核苷酸能促进顺铂诱导CEM细胞凋亡。     

雷公藤多甙对耐顺铂人上皮卵巢癌细胞体外活性的影响及机制研究

目的：探讨传统中药雷公藤多甙（Tripterygium Wilfordii HookF,GTW）对耐顺铂人上皮卵巢癌细胞体外活性的影响及机制研究。方法：将顺铂、不同浓度雷公藤多甙及二者联合处理SKOV3/DDP细胞24 h,于倒置相差显微镜及荧光倒置显微镜下观察细胞形态学变化;采用Hochest 33258染色法计算细胞平均凋亡率;流式细胞术检测细胞周期变化;Western blot检测P13K/Akt/NF-κB信号通路相关因子PI3K、T-AKT、p-AKT(ser473)、IκBα、NF-κB、Bcl-2的表达变化。结果：SKOV3/DDP细胞经不同浓度雷公藤多甙处理24 h后,出现典型的凋亡样改变;且凋亡率呈浓度依赖性,顺铂联合组凋亡率较相应单药组明显升高;SKOV3/DDP细胞经雷公藤多甙处理24 h后,S期细胞比例明显升高,升高程度呈浓度依赖性（P<0.05）,雷公藤多甙与顺铂联合组S期细胞比例与相应单药组相比均明显升高;雷公藤单药及雷公藤、顺铂联合处理SKOV3/DDP细胞24 h后,p-AKT、NF-κB、Bcl-2蛋白表达明显下调。结论：雷公藤多甙可使耐顺铂人上皮卵巢癌SKOV3/DDP细胞周期阻滞于S期并诱导其凋亡,与小剂量顺铂联用效用明显增加,其机制可能与p-AKT、 NF-κB、 Bcl-2表达下调,抑制P13K/Akt/NF-κB信号通路有关。     

芦荟苷通过降低热休克蛋白70的表达增强顺铂诱导的胃癌细胞凋亡

目的：探讨芦荟苷能否通过降低热休克蛋白70(HSP70)的表达,增强顺铂诱导的胃癌细胞凋亡。方法：胃癌HGC-27细胞分为对照组、200 mg/L芦荟苷组、5 mg/L顺铂组和两者联合组（200 mg/L芦荟苷+5 mg/L顺铂）。DAPI染色和流式细胞术分别检测细胞凋亡形态改变及凋亡率;RT-qPCR检测HSP70 mRNA的表达水平;Western blot检测HSP70和凋亡相关蛋白的表达;免疫沉淀（IP）检测HSP70的泛素化水平。结果：DAPI染色结果显示,与药物单独刺激组相比,联合组细胞核浓缩与核碎裂现象显著增强。流式细胞术分析细胞凋亡率表明,顺铂组细胞凋亡率为16.71%,显著高于对照组的6.95%(P<0.01)。虽然芦荟苷组与对照组相比,凋亡率无显著差异,但是其与顺铂联合作用后,细胞凋亡率为33.74%,显著高于顺铂和芦荟苷单独刺激组（P<0.01）。RT-qPCR显示,芦荟苷能够显著下调顺铂诱导的HSP70 mRNA表达（P<0.01）。Western blot结果表明,联合组cleaved PARP和cleaved caspase-3/-7的表达...     

赖氨大黄酸与顺铂联合对人肺癌A549细胞系增殖和凋亡的影响

目的研究赖氨大黄酸(RHL)、顺铂和两者联合对人肺癌A549细胞增殖和凋亡的影响及其作用机制,为RHL联合顺铂抗肺癌的临床实验研究提供理论依据。方法肺癌细胞系A549随机分为对照组、顺铂组、RHL组和顺铂联合RHL组,用MTT法和流式细胞术分别检测细胞48 h增殖和凋亡。Western blot法检测细胞48 h后凋亡相关蛋白和MEK/ERK蛋白的表达。结果细胞培养48 h后,顺铂组和RHL组的细胞增殖受到一定的抑制并有细胞凋亡发生,但两药联合后的增殖抑制作用和凋亡诱导作用显著高于单用顺铂和RHL组(P0.05)。顺铂和RHL均能上调caspase-3、caspase-7和poly ADP-ribose polymerase(PARP)的切割片断蛋白表达,但两药联合后caspase-3、caspase-7和PARP的切割片断蛋白表达进一步增高(P0.05),并显著下调Bcl-2蛋白的表达水平,上调Bax蛋白的表达水平,同时RHL还能降低顺铂上调的ERK蛋白磷酸化。结论 RHL能够通过抑制顺铂对ERK的激活、上调caspase-3、caspase-7和PARP的切割片断蛋白表达,增强顺铂对肺癌细胞增殖和凋亡诱导作用。     

赖氨大黄酸与顺铂联合对人肺癌A549细胞系增殖和凋亡的影响简

 目的 研究赖氨大黄酸（RHL）、顺铂和两者联合对人肺癌A549细胞增殖和凋亡的影响及其作用机制,为RHL联合顺铂抗肺癌的临床实验研究提供理论依据。方法 肺癌细胞株A549随机分为对照组、顺铂组、RHL组和顺铂联合RHL组,用MTT法和流式细胞术分别检测细胞48 h增殖和凋亡。Western blot 法检测细胞48h后凋亡相关蛋白和MEK/ERK蛋白的表达。结果 细胞培养48 h后,顺铂组和RHL组的细胞增殖受到一定的抑制并有细胞凋亡发生,但两药联合后的增殖抑制作用和凋亡诱导作用显著高于单用顺铂和RHL组(P<0.05)。顺铂和RHL均能上调caspase-3、caspase-7和poly ADP-ribose polymerase (PARP)的切割片断蛋白表达,但两药联合后caspase-3、caspase-7和PARP的切割片断蛋白表达进一步增高(P<0.05),并显著下调Bcl-2蛋白的表达水平,上调Bax蛋白的表达水平,同时RHL还能降低顺铂上调的ERK蛋白磷酸化。结论 RHL能够通过抑制顺铂对ERK的激活、上调caspase-3、caspase-7和PARP的切割片断蛋白表达,增强顺铂对肺癌细胞增殖和凋亡诱导作用。     

褪黑素对电离辐射诱导小鼠淋巴细胞凋亡的影响

目的:探讨褪黑素(MLT)对电离辐射诱导小鼠胸腺细胞和脾细胞凋亡的影响及其机制。方法:采用流式细胞术(FCM)和荧光分光光度法分别检测离体和在体小鼠淋巴细胞凋亡小体百分率和DNA裂解率。结果:在离体研究中,小鼠胸腺和脾淋巴细胞体外接受(0.5-6.0)Gy X射线照射前预先加入2 mmol/L MLT,细胞凋亡小体百分率和DNA裂解率均显著低于单纯照射组,胸腺和脾淋巴细胞凋亡小体百分率分别为单纯照射组的86.25％和89.44％,DNA裂解率分别为单纯照射组的87.23％和89.16％。在体研究中,2 Gy X射线全身照射前60 min腹腔注射MLT,小鼠胸腺和脾淋巴细胞凋亡小体百分率和DNA裂解率显著低于单纯照射组,接近或低于假照水平,MLT剂量在0.1-2.5 mg／kg范围内均有作用,但无明显剂量依赖性。结论:MLT在体内和体外均可减轻电离辐射诱导的小鼠淋巴细胞损伤,且体内比体外作用更明显。     

虫草素增强顺铂诱导的食管癌细胞系Eca109凋亡

目的研究虫草素与顺铂联合用药对食管癌细胞Eca109凋亡的影响及其作用机制。方法将食管癌细胞Eca109分为对照组、不同浓度虫草素处理组、不同浓度顺铂处理组和虫草素(70μg/m L)与顺铂(0.8μg/m L)联合处理组。MTS法检测Eca109细胞增殖;Hoechst 33258染色法及流式细胞术检测Eca109细胞凋亡;Western blot法检测细胞核内NF-κB P65及凋亡相关蛋白Bcl-2和Bax表达水平;ELISA法检测细胞核内NF-κB P65与DNA的结合活性。结果虫草素与顺铂联合应用使顺铂对Eca109细胞的抑制率由29.30%增加至70.41%(P0.05),增强了顺铂对Eca109的敏感性;与顺铂单独用药相比,联合用药能够显著增加顺铂诱导的细胞凋亡(P0.05);与对照组相比顺铂能够增加细胞核内NF-κB P65的活性,而虫草素却能抑制NF-κB P65的活性,联合用药后NF-κB P65的活性下调;与虫草素和顺铂单独用药相比,联合用药组能够使抗凋亡蛋白Bcl-2的表达显著降低(P0.05),而促凋亡蛋白Bax表达则显著增高(P0.05)。结论虫草素可能通过抑制NF-κB途径,调节下游信号分子Bcl-2和Bax的表达,增强顺铂对Eca109的凋亡诱导效应。     

虎杖苷与顺铂联合增强卵巢癌SKOV3细胞的凋亡作用

目的考察虎杖苷和顺铂联合给药对人卵巢癌SKOV3细胞增殖及凋亡的作用机制。方法 SKOV3细胞分为虎杖苷和顺铂分别及联合给药组,采用MTT法检测对细胞增殖抑制的影响;流式细胞仪检测细胞的凋亡率,并观察细胞晚期凋亡(48h)的形态学变化;Western blot检测凋亡蛋白和线粒体通路相关蛋白的表达水平。结果 MTT结果显示SKOV3细胞在虎杖苷和顺铂联合给药后明显降低细胞存活率,且呈时间和浓度依赖性;单克隆形成实验结果显示虎杖苷与顺铂联合给药抑制细胞增殖的能力增强;AnnexinV-FITC单染检测细胞凋亡率显示,与顺铂给药组相比,联合给药组细胞凋亡率增加11.5%;Western blot检测结果表明联合给药组与顺铂单药给药组相比,凋亡蛋白cleaved PARP、cleaved caspase-9的表达均增强;线粒体凋亡相关蛋白Bax升高,Bcl-2降低。结论虎杖苷和顺铂联用能增强顺铂对细胞增殖的抑制作用,促进细胞凋亡,初步阐明联合给药的抗癌机制是通过线粒体凋亡途径所介导。     

Expression of apoptosis-related proteins and morphological changes in a rat tumor model of human small cell lung cancer prior to and after treatment with radiotherapy,carboplatin, or combined treatment

PURPOSE: In order to understand the apoptosis pathway in tumor cells, differences in cell morphology and expression of apoptosis-related proteins induced by radiation and/or chemotherapy, were investigated in a rat double tumor model comparing cisplatin-sensitive and -resistant human small cell lung cancer tumors. METHODS: The cisplatin-sensitive human small cell lung cancer cell line (GLC4) and its cisplatin-resistant subline (GLC4-CDDP) were each injected subcutaneously in a different hind limb of the rat. After 15-17 days, radiation (10 Gy), carboplatin (25 mg/kg, intraperitoneal), combined treatment, or no treatment was administered. In combined treatment, carboplatin was administered 24 h before radiation. Tumors were removed and fixed 72 h after carboplatin or 48 h after radiation. Paraffin-embedded slides were stained with hematoxylin/eosin for morphology. Expression of the apoptosis-related proteins p53, p21, Rb, bcl-2, bax, c-myc, Fas and Fas-L was assessed immunohistochemically. RESULTS: In the GLC4 tumor, carboplatin treatment increased tumor cell size, tumor cell size heterogeneity, and number of apoptotic tumor cells. After radiation and combined treatment, these changes were more pronounced and multinuclear giant cells were observed. In GLC4-CDDP tumors, minimal changes were detected after carboplatin. Following radiation slight increases in tumor cell size, tumor cell size heterogeneity and number of apoptotic tumor cells were observed. No multinuclear giant cells were seen. After combined treatment, GLC4-CDDP showed cellular changes comparable to those in GLC4 cells after radiation or combined treatment, but no giant cells were observed. Untreated, both tumors were equally positive for p53, bax, Fas, Fas-L, c-myc and negative for Rb. Contrary to GLC4, untreated GLC4-CDDP tumors showed no p21 and bcl-2 expression. After combined treatment, an increase in number of bcl-2 positive cells was found in GLC4-CDDP tumors. No p21 was induced in GLC4-CDDP by any treatment modality. In GLC4 tumors, p21 was induced by radiation alone. No further changes in protein expression were induced by any treatment in GLC4 tumors. CONCLUSION: Following therapy, morphological changes in cell size and cell size heterogeneity were more pronounced in GLC4 than in GLC4-CDDP tumors. However, morphological changes in GLC4-CCDP tumors after treatment indicate that carboplatin plus radiotherapy may be effective also in cisplatin resistant tumor cells. An increase in p21 in GLC4 after radiation might facilitate apoptosis. The increase in number of Bcl-2 positive cells after combined treatment and the consistently negative p21 status after any treatment in GLC4-CDDP may protect these tumor cells from apoptosis as a part of their resistance mechanism to cisplatin.     

Apoptosis of tubulointerstitial chronic inflammatory cells in progressive renal fibrosis after cancer therapies

Progressive renal fibrosis is an unwanted and limiting side effect of cancer treatments, whether they are systemic (for example, chemotherapy), local (for example, radiotherapy), or total body irradiation for allogenic bone marrow transplants. The relative roles of macrophages, myofibroblasts, and lymphocytes and the apoptotic deletion of renal functional or inflammatory cell populations in the pathogenesis of renal fibrosis are yet unclear. In this study, rat models of 2 renal cancer treatments: cis-platinum-(II)-diammine dichloride (cisplatin, 6-mg/kg body weight) and radiation (single dose of 20 Gy) were used. Kidneys were analyzed 4 days to 3 months after treatment. The extent of renal fibrosis was compared with number and localization of chronic inflammatory cell populations, cell death (apoptosis and necrosis), and expression and localization of profibrotic growth factors transforming growth factor-beta1 (TGF-beta1) and tumor necrosis factor-alpha (TNF-alpha). The models provided contrasting rates of fibrogenesis: After cisplatin, development of fibrosis was rapid and extensive (up to 50% fibrosis at 3 months); in comparison, radiation-induced fibrosis was slowly progressive (approximately 10% fibrosis at 3 months). The extent of fibrosis was associated spatially and temporally with increasing numbers of myofibroblasts with TGF-beta1 or macrophages with TNF-alpha. Tubular epithelial apoptosis was highest with high TNF-alpha (P<0.05). A significant inverse correlation existed between extent of tubulointerstitial fibrosis and interstitial cell apoptosis for cisplatin and a similar nonsignificant result for radiation (r(2)=0.8671 for cisplatin, P<0.05; r(2)=0.2935 for radiation, NS). The latter result suggests a role for inflammatory cell apoptosis in minimizing development of renal fibrosis.     

The synergistic effects of hyperthermia and anticancer drugs on induction of apoptosis

We studied the synergistic effects of hyperthermia and anticancer drugs on induction of apoptosis in lung cancer cells (LK-2 and LU-65A) using in situ end-labeling of DNA, the DNA fragmentation assay, and transmission electron microscopy. A few apoptotic cells were detected only when both cell lines were heated at relatively high temperature (44 degrees C). Moderate numbers of apoptotic cells were observed when both cell lines were incubated with high concentrations (30 or 40 microM) of anticancer drug. Compared with hyperthermia or anticancer drug alone, the combined treatment induced many apoptotic cells in both cell lines, even in the cells treated with lower concentrations (6 or 8 microM) of anticancer drugs following mild hyperthermia (43 degrees C). In regard to kinetics of apoptotic cells induced by treatment, the maximum induction of apoptosis by the combined treatment was higher than that of hyperthermia or anticancer drug alone in both cell lines, although the time of the peak of apoptotic index differed among the three treatments. Therefore, "hyperthermo-chemotherapy" may reduce the required dosage of anticancer drug and decrease the temperature of hyperthermia on induction of apoptosis.     

桂皮酸联合顺铂对人肝癌MHCC97细胞的增殖抑制和凋亡诱导作用

 目的： 探讨桂皮酸（cinnamic acid,CA）联合顺铂（cisplatin）对人肝癌细胞株MHCC97的增殖抑制及凋亡诱导作用。方法：以人肝癌细胞株MHCC97为研究对象,分为正常对照组、CA组、cisplatin组和CA+cisplatin组。采用MTT比色法检测细胞活性,倒置显微镜下观察细胞凋亡形态学变化,膜联蛋白V/碘化丙啶双染流式细胞术定量检测细胞凋亡率, Western blotting法检测凋亡蛋白caspase-3的活化。结果：CA单用或与cisplatin联用对正常人肝细胞L-02未见明显抑制作用,但两药单用或联用可明显抑制肝癌细胞MHCC97的增殖并诱导其凋亡。CA单用或与cisplatin联合作用于MHCC97细胞,其早期凋亡率比cisplatin组高,而中晚期凋亡及坏死率却相反。联用组在低浓度时具有很好的促凋亡作用,其促凋亡活力强于CA或cisplatin单用组,且联用可起到显著减毒增效的作用。 CA和cisplatin单用或联用均可促进caspase-3蛋白的活化,具有时间正效应,且CA组和联合组的cleaved caspase-3蛋白表达量高于cisplatin组。结论：CA和cisplatin联合应用或单用均能有效抑制MHCC97细胞增殖,诱导其凋亡,其机制可能与激活caspase-3表达有关。     

Enhancement of radiation response with combined Ganoderma lucidum and Duchesnea chrysantha extracts in human leukemia HL-60 cells

We previously demonstrated that combined treatment with extracts of the medicinal mushroom Ganoderma lucidum and the herb Duchesnea chrysantha (GDE) significantly suppresses cell growth and selectively induces apoptosis in human leukemia HL-60 cells, but not in normal cells. GDE?s mechanism of action and its activity against HL-60 cells suggest that it could be suitable for the combined-modality treatment of hematological malignancies. In the present study, we examined whether treatment with a combination of GDE and ionizing radiation enhances the therapeutic effect. We demonstrated that, when used in combination with radiation at a clinically relevant dose of 2 Gy, GDE further suppressed cell proliferation and induced apoptosis as well as micronuclei formation in HL-60 cells, leading to increased cell death. Furthermore, GDE pretreatment not only reduced radiation-induced G2/M-phase arrest, but also induced G1-phase arrest. These events are associated with the inhibition of cyclin-dependent kinase 1 (CDK1) phosphorylation and the dephosphorylation of retinoblastoma protein (pRB). Collectively, these data show that combined treatment with GDE and radiation enhances radiation-induced apoptosis and overall cell death. These findings may be clinically relevant and suggest a novel therapeutic strategy for increasing the efficacy of radiotherapy.     

紫草素对卵巢癌细胞SKOV3/DDP顺铂耐药的逆转作用

目的:探讨紫草素是否逆转卵巢癌细胞SKOV3/DDP的顺铂耐药效应及其作用机制。方法:采用CCK-8法确定紫草素和顺铂的最佳作用条件,流式细胞术检测细胞的周期分布及凋亡率;Western blot检测周期及凋亡相关调控因子细胞周期蛋白D1(cyclin D1)、周期蛋白依赖性激酶2(CDK2)、P18、p-Rb、Bcl-2、Bax和cleaved caspase-3的蛋白水平。结果:CCK-8实验结果显示,相较于单用顺铂,联合使用紫草素对顺铂耐药卵巢癌细胞SKOV3/DDP的生长抑制作用较为显著。此外,联用紫草素和顺铂可显著抑制细胞周期G_1/S转化,并增加细胞早期凋亡率。Western blot结果显示,相较于顺铂处理组,紫草素和顺铂联用组的cyclin D1、CDK2、p-Rb及Bcl-2的蛋白水平显著降低,而P18、Bax及cleaved caspase-3的蛋白表达显著增加。结论:紫草素可逆转卵巢癌SKOV3/DDP细胞的顺铂耐药效应,其作用机制可能与影响细胞周期及凋亡相关因子的表达,进而抑制细胞活力促进细胞凋亡相关。     

Apoptosis of hemopoietic cells in irradiated mouse bone marrow.

Apoptosis of hemopoietic cells in bone marrow following radiation has been rarely reported, let alone studied quantitatively and pathologically. LACA mice were irradiated with 2.5, 4.0, 5.5, and 7.0 Gy gamma-rays, and the bone marrow was examined at 6 hours, 1 day, and 3 days after radiation. Semi-thin and thin sections were examined by light and electron microscopy. The number and area density of the apoptotic cells were assessed by means of a Cambridge Quantimet 970 Image Analyzer. We found that apoptosis occurred in only a few hemopoietic cells in the control mouse bone marrow, whereas 6 hours after radiation there were many apoptotic hemopoietic cells in each sample of irradiated bone marrow. Compared with controls, both the number and area density of the apoptotic cells markedly increased in the bone marrow of animals in every radiation dose group, and the difference was statistically significant (p < 0.01). Furthermore, the number and area density increased as the radiation dose increased. Our findings suggest that apoptosis is the main mode of radiation-induced hemopoietic cell death.     

Isorhamnetin flavonoid synergistically enhances the anticancer activity and apoptosis induction by cis-platin and carboplatin in non-small cell lung carcinoma (NSCLC)

The development of novel antitumor drugs for the treatment of non-small cell lung carcinoma NSCLC is imperative in order to improve the efficacy of lung cancer therapy and prognosis. In the current study, we demonstrated the antitumor activity of isorhamnetin and its combinations with cisplatin and carboplatin against A-549 lung cancer cells. In order to assess the anticancer enhancing effect of isorhamnetin on cisplatin and carboplatin, A-549 cells were treated with isorhamnetin, cisplatin, carboplatin and their combinations and cell viability, cell apoptosis, cell cycle arrest as well as loss of mitochondrial membrane potential were evaluated by MTT assay, flow cytometry, confocal microscopy and fluorescence microscopy. The effect of the drugs on cancer cell migration, microtubule depolymerization as well activation of caspases was also studied. The results revealed that, as compared to single drug treatment, the combination of isorhamnetin with cisplatin and carboplatin resulted in greater effect in inhibiting cancer cell growth and inducing apoptosis. Combination of isorhamnetin with cisplatin and carboplatin resulted in more potent apoptosis induction as revealed by fluorescence microscopy using AO/PI double staining. Isorhamnetin and its combinations also triggered microtubule distortion and depolymerization. The combination of isorhamnetin with cisplatin and carboplatin increased the number of cells in G2/M phase dramatically as compared to single drug treatment. Moreover, isorhamnetin and its combinations with known anticancer drugs induced disruption of the mitochondrial membrane potential as well as activation of caspases 3, 9 and poly-(ADP-ribose) polymerase in A-549 cells. Isorhamnetin as well as its combinations with cisplatin and carboplatin resulted in inhibition of cancer cell migration significantly. Results of the current study suggest that isorhamnetin combinations with cisplatin and carboplatin might be a potential clinical chemotherapeutic approach for NSCLC.     

Change in the frequency of apoptosis after low- and high-dose X-irradiation of human lymphocytes.

The purpose of the present study was to correlate the type and frequency of cell death in human lymphocytes receiving variable doses of X-irradiation. Monocyte-depleted lymphocyte fractions were exposed in vitro to variable doses of X-rays of 0-20 Gy (0-2000 rads) and incubated for 4 and 16 h. An assessment of the mode of cell death (apoptosis vs. classical necrosis) was carefully evaluated using a multidisciplinary approach using light, fluorescence and electron microscopy (EM), and dye exclusion assays. Eosin Y exclusion assays indicated the absence of classical necrosis occurring in short-term cultures (4 h postirradiation). An assessment of cell counts, however, revealed a mean decrease of 4% at 0 Gy and 13% at 10-20 Gy (1000-2000 rads). The predominant mode of cell death was apoptosis, but the percent apoptotic cells (determined by EM) did not parallel this increase in cell loss with increasing radiation and actually decreased at doses above 5 Gy (500 rads). The discrepancy between percent cell loss and percent apoptosis was explained by a proposed change in overall duration of the apoptotic process. In long-term cultures (16 h postirradiation), a combination of classical necrosis, classical apoptosis, and combined apoptosis and necrosis (secondary necrosis of apoptotic cells) was apparent and was associated with a marked decrease in viability. Irradiation effects on lymphocytes showing none of the morphologic features of apoptosis or classical necrosis in short-term culture were evidenced by an increase in nuclear lobation. The results of this study indicate that the vast majority of peripheral blood lymphocytes are radioresistant. The use of irradiation in an in vitro model to study the biochemical events of the apoptotic process is also evaluated.