紫杉醇抗人骨肉瘤作用的实验研究

 目的 研究紫杉醇抗骨肉瘤作用及其机制。方法 应用MTT法、形态学观察、AO／EB染色、流式细胞术等方法观察和检测紫杉醇对人骨肉瘤细胞系MG-63、新鲜骨肉瘤组织块及荷瘤裸鼠的毒性作用和bcl-2、baX基因的表达变化。结果 紫杉醇对骨肉瘤细胞具有毒作用，呈现一定的时间和剂量依赖性，并能下调bcl-2基因的表达，诱导骨肉瘤细胞凋亡，caspase抑制剂能部分阻断此种过程。结论 紫杉醇抗骨肉瘤作用明显，可用于骨肉瘤化疗。     

熊果酸诱导结肠癌HT-29细胞凋亡的实验研究

目的探讨熊果酸（UA）诱导结肠癌HT-29细胞凋亡的作用及机制。方法用不同浓度的UA处理HT-29细胞,采用四甲基偶氮唑蓝（MTT）比色法,检测UA对HT-29细胞的增殖抑制效应;采用形态学、TUNEL法和流式细胞术,检测细胞凋亡的发生;应用免疫组织化学S-P法,检测凋亡相关基因caspase-9和bcl-2的表达,并用病理图像分析软件进行半定量分析。结果UA在体外对HT-29细胞有中度增殖抑制效应,在UA作用下,HT-29细胞出现显著的细胞凋亡征象。TUNEL法显示细胞固缩,核染色质聚集或断裂,形成凋亡小体。流式细胞术检测结果显示,在G1期之前出现Sub—G1峰,凋亡率最高为11．63％,UA的作用具有浓度和时间依赖性。在HT-29细胞凋亡过程中,凋亡相关基因caspase-9的表达增强,bcl-2的表达减弱。结论凋亡是UA杀伤肿瘤细胞的机制之一;UA诱导结肠癌HT-29细胞凋亡主要与促进caspase-9的活化、下调bcl-2的表达有关。     

蟾毒灵诱导骨肉瘤U-2OS和U-2OS/MTX300细胞系的凋亡

目的 研究蟾毒灵对人骨肉瘤细胞株的增殖抑制和诱导凋亡作用.方法 以不同浓度的蟾毒灵分别作用于骨肉瘤细胞U-2OS和甲氨蝶呤(MTX)耐药骨肉瘤细胞U-2OS/MTX300.采用四甲基偶氮唑蓝(MTT)法检测细胞增殖,Hoechst 33258荧光染色检测细胞凋亡,流式细胞仪检测细胞周期,DNA琼脂糖凝胶电泳检测DNA ladder凋亡条带,Western blot法检测凋亡相关蛋白p53、bax和bcl-2的表达.结果 蟾毒灵能明显抑制骨肉瘤细胞的增殖,其对U-2OS和U-2OS/MTX300细胞的IC50值分别为(8.49±2.1)ng/ml和(10.19±1.7)ng/ml(P＞0.05).蟾毒灵处理U2OS和U-2OS/MTX300细胞48 h后,细胞均出现明显的染色质凝集,有典型的凋亡小体产生.同时,蟾毒灵能诱导骨肉瘤细胞凋亡,其作用机制是通过阻滞细胞周期于G2/M期、上调p53、bax表达和下调bcl-2的表达来实现.结论 蟾毒灵能显著抑制人骨肉瘤细胞U-2OS和U-2OS/MTX300的生长,并诱导细胞凋亡,其抗骨肉瘤作用不受MTX耐药的影响.     

紫杉醇脂质体对乳腺癌MCF-7细胞生长抑制作用的机制

目的 分析紫杉醇脂质体对乳腺癌MCF-7细胞的生长抑制作用,观察药物作用的时间浓度关系并探究其作用机制.方法 应用不同剂量紫杉醇脂质体对MCF-7细胞进行处理,通过MTT法检测细胞存活率,倒置显微镜观察细胞形态,流式细胞分析技术检测细胞凋亡情况及其对细胞周期的影响,Western blot法检测bcl-2蛋白表达情况.结果 紫杉醇脂质体对MCF-7细胞有明显的剂量时间依赖效应.紫杉醇与紫杉醇脂质体均可将MCF-7细胞阻滞在G2/M期,且随药物浓度增加,凋亡细胞所占比例逐渐增加.通过Western blot法检测发现,紫杉醇脂质体作用后MCF-7细胞bcl-2蛋白表达明显下降,bax蛋白表达明显上调,bax/bcl-2比例明显上调.结论 与紫杉醇相比,紫杉醇以脂质体对人乳腺癌MCF 7细胞具有同样的抑制作用,其促凋亡机制之一为调控bcl-2及bax蛋白表达.     

二氯乙酸钠对人骨肉瘤MG63细胞周期及凋亡影响的初步研究

目的 探讨不同浓度的二氯乙酸钠(DCA)对人骨肉瘤MG63细胞活性、周期及凋亡的影响.方法 用含质量分数10％胎牛血清的RPMI-1640培养基培养MG63细胞,不同浓度DCA作用于对数生长期的细胞,CCK8试剂盒检测50、100、200 μg·mL-1DCA处理24 h、48 h后细胞增殖情况;流式细胞术检测100、200 μg·mL-1 DCA-Na作用24 h、48 h后细胞周期和凋亡情况;qRT-PCR检测100、200 μg·mL-1DCA处理后细胞周期相关基因CDK2的变化.结果 CCK8检测结果显示50、100、200 μg· mL-1DCA均能抑制MG63细胞的生长,且有时间和浓度依赖性;不同浓度的DCA-Na分别干预MG63细胞不同时间后都明显阻滞细胞于G2/M期,且细胞凋亡率增加(P均＜0.001);不同浓度的DCA干预MG63细胞后,细胞中的CDK2mRNA的相对表达量明显降低(P均＜0.001).结论 DCA通过抑制CDK2使MG63细胞阻滞于G2/M期,进而诱导细胞凋亡,抑制细胞的生长.     

熊果酸诱导人胃癌BGC823细胞凋亡及其作用机制初探

背景与目的：熊果酸（ursolic acid,UA）广泛存在于夏枯草、白花蛇舌草等清热解毒药中,可抑制多种肿瘤细胞增殖并诱导其凋亡,具有广泛生物学活性。本研究将UA作用于人胃癌BGC823细胞,观察其对细胞凋亡的影响,并探讨其可能的作用机制。方法：MTT法检测UA对BGC823细胞增殖的影响;流式细胞术检测细胞周期与凋亡的变化;Realtime-PCR检测细胞bax、bcl-2mRNA表达的变化。结果：UA呈时间-剂量依赖性抑制BGC823细胞增殖,分别作用24、48、72h后半数抑制浓度依次为36.88、34.72、32.18μmol/L;UA能诱导BGC823细胞凋亡,并阻滞细胞于G2/M期;此外,其还可上调BGC823细胞bax及下调bc1-2mRNA表达,且作用随剂量的增加而加强。结论：UA呈时间-剂量依赖性抑制BGC823细胞增殖,并诱导其凋亡,阻滞细胞于G2/M期;其凋亡机制可能与上调bax及下调bcl-2基因的表达有关。     

紫杉醇对人膀胱移行上皮细胞癌的体外作用

目的:观察紫杉醇对人膀胱移行上皮癌细胞系增殖、细胞凋亡以及p53、bax、bcl-2和caspase3基因表达的影响。方法:体外培养膀胱移行细胞癌细胞系BIU-87、5637、T24、EJ细胞;用MTT法检测紫杉醇对各种癌细胞生长抑制的影响;用流式细胞技术(碘化丙啶)检测紫杉醇对癌细胞周期影响;流式细胞仪Annexin-V法测定细胞凋亡率;流式免疫荧光检测用药前后p53、bax、bcl-2、和caspase3基因表达变化。结果:紫杉醇对体外培养的膀胱移行细胞癌细胞系均有抑制作用,具有时间和浓度依赖性;低分级肿瘤和倍增时间长的细胞系对紫杉醇敏感性高;紫杉醇作用5637和EJ细胞24小时,导致细胞G_2期71.29%与64.57%的阻滞;1μg/ml作用5637细胞12、24、48小时,凋亡率分别为5.0%、12.9%、及27.6%;免疫荧光显示p53、bcl-2表达没有显著性变化,而bax、caspase3却随紫杉醇时间延长表达升高。结论:紫杉醇对膀胱移行细胞癌具有抑制作用,细胞分级低、倍增时间长的癌细胞系对紫杉醇更敏感。紫杉醇阻滞细胞于G_2/M,诱导bax表达上调可能是产生膀胱癌细胞凋亡的原因。     

蛋白酶体抑制剂Z-LLL-CHO对人骨肉瘤细胞株MG-63作用的体外研究

目的　探讨蛋白酶体抑制剂Z LLL CHO对人骨肉瘤细胞株MG 63的作用 ,并探讨其作用机制。方法　将不同浓度的Z LLL CHO作用于骨肉瘤细胞株MG 63 ,采用荧光显微镜观察细胞形态改变、电镜观察细胞超微结构变化、MTT法检测细胞增殖活力、琼脂糖凝胶电泳检测细胞凋亡、流式细胞仪分析细胞凋亡率及细胞周期改变。结果　Z LLL CHO可有效抑制MG 63细胞株的生长 ,并诱导细胞发生凋亡。凋亡细胞表现为浓染致密的颗粒块状荧光 ,胞核固缩、染色质凝聚并边缘化 ,DNA呈“阶梯状”排列的条带。流式细胞仪分析显示 ,Z LLL CHO在 1.0 μmol/L作用 2 4h、3 6h、48h后 ,细胞凋亡率分别为 5 .4%、2 0 .5 %、5 2 .7%。随药物浓度增高及作用时间延长 ,细胞周期被阻滞于G2 /M期。结论　蛋白酶体抑制剂Z LLL CHO可有效抑制人骨肉瘤MG 63细胞株的生长增殖 ,阻滞细胞周期及诱导细胞凋亡可能起重要作用。     

紫杉醇和吉西他滨对鼻咽癌HNE_2细胞系协同放射增敏的作用

 目的观察紫杉醇、吉西他滨两药联合对鼻咽癌细胞系HNE2的放射增敏作用,并探讨其可能机制。方法将HNE2细胞分为单纯照射组、吉西他滨(GE)+照射组、紫杉醇(PA)+照射组及GE+PA+照射组,用克隆形成实验计算两药物单用及合用的放射增敏比,流式细胞仪法分别检测、比较各组的细胞凋亡率及细胞周期变化。Westernblot法测定各组细胞凋亡相关基因bcl-2、bax的表达水平。结果吉西他滨、紫杉醇及两药联合使用的放射增敏比分别为1.06、1.13和1.34。流式细胞仪检测显示吉西他滨联合射线主要诱导S期阻滞(96.03%),诱导凋亡率为31.62%;紫杉醇联合射线引起的阻滞以G2+M期为主(75.71%),诱导细胞凋亡率为44.56%;两药合用并联合照射后G2+M期比例(65.98%)有所下降,同时S期比例(33.33%)有所上升(与PA+放射组比较),细胞凋亡率达到73.28%。在四组中bcl-2的表达呈逐步下降趋势,而bax的表达则呈逐步上升趋势。结论吉西他滨、紫杉醇单用及两药联合对鼻咽癌细胞系HNE2均有放射增敏作用,且两者协同增敏作用显著高于单独增敏作用,显示了两药联合应用有助于提高鼻咽癌的放射敏感性。两...     

大蒜素对骨肉瘤MG-63细胞系增殖和凋亡的影响

目的观察大蒜素对人成骨肉瘤细胞株MG-63增殖和凋亡的影响。方法不同浓度的大蒜素作用于体外培养的MG-63细胞,倒置显微镜下观察MG-63细胞的形态学变化,采用CCK-8法检测大蒜素对MG-63细胞增殖抑制能力,吖啶橙/溴化乙锭双荧光染色及Annexin V-FITC标记流式细胞术检测细胞凋亡情况以及对MG-63细胞周期影响。结果大蒜素可抑制人成骨肉瘤细胞株MG-63细胞增殖,具有明显剂量和时间依赖性,10 μg/ml大蒜素可明显诱导MG-63细胞凋亡,并将细胞周期阻滞在G2/M期。结论大蒜素能够诱导MG-63细胞凋亡,阻滞细胞周期,抑制细胞增殖。     

腺病毒介导VEGF-siRNA对荷人骨肉瘤裸鼠移植瘤生长的影响

目的:观察腺病毒介导的VEGF-siRNA对荷人骨肉瘤细胞株MG63裸鼠移植瘤生长的影响。方法:将Ad-VEGF-siRNA感染MG63,用噻唑蓝(thiazolyl blue,MTT)法检测细胞体外增殖活力,反转录-聚合酶链反应(reverse transeription-poly-merase chain reaction,RT-PCR)法检测VEGF抑制效果。建立裸鼠移植瘤模型,定期瘤内注射Ad-VEGF-siRNA,观察裸鼠致瘤率、肿瘤体积、抑瘤率及免疫组化法检测肿瘤组织中bcl-2的表达。结果:感染Ad-VEGF-siRNA能明显抑制MG63细胞的生长,瘤灶内注射Ad-VEGF-siRNA后裸鼠移植瘤的质量和体积均显著低于对照组(P<0.01)。TUNEL染色显示肿瘤细胞凋亡增加,免疫组化结果提示肿瘤组织中bcl-2表达明显减少(P<0.01)。结论:Ad-VEGF-siRNA可有效而特异地阻断VEGF基因表达,抑制裸鼠移植瘤生长,促进肿瘤细胞的凋亡。     

Effects of Kruppel-like factor 6 on osteosarcoma cell biological behavior

Kruppel-like factor 6 (KLF6) is a tumor suppressor gene frequently downregulated in a number of human cancers, including osteosarcoma. However, the role of KLF6 in osteosarcoma remains unclear. This study was aimed at investigating the effects of KLF6 on osteosarcoma cell biological behavior. First, the expression of KLF6 in osteosarcoma cell lines (MG63, SaOS-2, U2OS, and HOS) and a human osteoblastic cell line (hFOB1.19) was detected by Western blotting. Results showed that KLF6 displayed a significant downregulation in osteosarcoma cell lines (MG63, SaOS-2, U2OS, and HOS) compared with human osteoblastic cell line (hFOB1.19). To investigate the role of KLF6 in osteosarcoma cell proliferation, apoptosis, and invasion, we generated human osteosarcoma MG63 cells in which KLF6 was either overexpressed or depleted. The MG63 cell viability, cycle, apoptosis, and invasive ability were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide staining, propidium iodide (PI) staining, Annexin-V-FITC/PI double staining, and Transwell invasion experiment, respectively. Results showed that the viability, proliferation, and invasive abilities were suppressed, and the apoptosis was enhanced in MG63 cells with overexpression of KLF6. The viability, proliferation, and invasive abilities were improved, and the apoptosis was inhibited in MG63 cells with knockdown of KLF6. At the same time, these molecules, including p21, bcl-2, and MMP-9, associated with the events about cell cycle, apoptosis, and invasion, were detected. Results showed that the expressions of bcl-2 and MMP-9 were downregulated, and the expressions of p21 were upregulated in the MG-63 cells with overexpression of KLF6. Taken together, our results suggested that KLF6 could inhibit proliferation and invasion, and facilitate apoptosis of osteosarcoma cells, which might be a potential target for the treatment of osteosarcoma.     

Prognostic value of bax, bcl-2, and p53 staining in primary osteosarcoma

BACKGROUND AND OBJECTIVES: To investigate the immunohistochemical expression of three apoptosis-related genes (bax, bcl-2, and p53) and apoptosis (TUNEL) in patients with primary osteosarcoma, and examine potential correlations between gene expression and clinicopathological characteristics in these patients. MATERIALS AND METHODS: Thirty-five primary osteosarcoma specimens and 18 tissue specimens deriving from non-malignant osseous lesions were immunohistochemically stained for bax, bcl-2, and p53 proteins, while apoptosis was investigated by the TUNEL method. The results were statistically analyzed. RESULTS: P53, bax, and bcl-2 protein expression was observed in 22 (62.9%), 29 (82.9%), and 18 (51.4%) osteosarcoma patients, respectively. Non-specific positive TUNEL staining (+/-) was observed in two primary osteosarcoma cases (5.7%). None of the benign controls expressed any of the genes studied. None of the apoptosis-related genes studied was able to predict overall or disease-free survival in our group of patients. Nevertheless, increased bax/bcl-2 protein expression ratio was associated with a decreased 4-year survival and disease free survival (P = 0.0229 and P = 0.0370, respectively). Furthermore, all the patients who were bax(+)/bcl-2(-)/p53(+) relapsed within the 4-year follow-up period (P = 0.0385). CONCLUSIONS: The increased apoptotic rate as determined by an elevated bax/bcl-2 protein expression ratio or by the bax(+)/bcl-2(-)/p53(+) protein expression pattern, appears to identify groups of osteosarcoma patients with unfavorable prognosis.     

大豆异黄酮诱导人食管癌裸鼠移植瘤细胞凋亡

[目的]研究大豆异黄酮诱导裸鼠EC-7906移植瘤凋亡的机制.[方法]建立人食管癌EC-7906裸鼠移植瘤模型,采用不同剂量的大豆异黄酮进行瘤旁注射,并设生理盐水和二甲亚砜(DMSO)两个对照组,用透射电镜和TUNEL法检测肿瘤组织细胞凋亡情况,免疫组织化学法和RT-PCR法检测肿瘤组织的凋亡相关基因bcl-2和bax的表达情况.[结果]透射电镜和TUNEL法发现大豆异黄酮导致移植瘤内大量细胞发生凋亡;免疫组织化学法发现大豆异黄酮注射组瘤组织的bcl-2蛋白表达阳性率降低,bax蛋白表达阳性率明显提高;RT-PCR法发现大豆异黄酮注射组的bcl-2 mRNA条带密度随剂量的增大而递减,bax mRNA条带密度递增,[结论]大豆异黄酮对人食管癌EC-7906裸鼠移植瘤具有抑制作用,通过下调bcl2的表达和上调bax的表达而诱导食管癌移植瘤细胞发生凋亡.     

MicroRNA 181a improves proliferation and invasion, suppresses apoptosis of osteosarcoma cell

MicroRNA 181a (miR-181a) was found dysregulated in a variety of human cancers and significantly associated with clinical outcome of cancer patients. However, the direct role of miR-181a has not yet been characterized in osteosarcoma progression. This study was aimed at investigating the effects of miR-181a on osteosarcoma cell biological behavior. First, the expression of miR-181a in osteosarcoma cell lines (MG63, HOS, SaOS-2, and U2OS) and a human osteoblastic cell line (hFOB1.19) was detected by qRT-PCR. Results showed that miR-181a was overexpressed in osteosarcoma cell lines compared to human osteoblastic cell line (hFOB1.19). To investigate the effects of miR-181a on proliferation, apoptosis, and invasion of osteosarcoma cells, we generated human osteosarcoma MG63 cells in which miR-181a was either overexpressed or depleted. The MG63 cell viability, cycle, apoptosis, and invasive ability were analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide staining, propidium iodide (PI) staining, Annexin V-FITC/PI double staining, and Transwell invasion experiment, respectively. The results showed that MG63 cell viability, proliferation, and invasive abilities were suppressed, and the apoptosis was enhanced in the group with underexpression of miR-181a. The viability, proliferation, and invasive abilities were improved, and the apoptosis was inhibited in the group with overexpression of miR-181a. The results from Western blotting indicated that miR-181a might be associated with the up-regulation of bcl-2 and matrix metalloproteinase 9 and the down-regulation of tissue inhibitor of metalloproteinases-3 and p21 in MG63 cells. Taken together, our results suggested that miR-181a might facilitate proliferation and invasion and suppress apoptosis of osteosarcoma cells, which might be a potential target for the treatment of osteosarcoma.     

The tumor suppressor p33ING1b enhances taxol-induced apoptosis by p53-dependent pathway in human osteosarcoma U2OS cells

p33ING1b can stimulate cell cycle arrest, DNA repair, apoptosis and chemosensitivity. The actions of p33ING1b involve p53-dependent and p53-independent mechanisms. To investigate if the p33ING1b isoform is involved in the chemosensitivity of osteosarcoma cells, p33ING1b was overexpressed in p53+/+ U2OS cells or p53-mutant MG63 cells, and then cell growth arrest and apoptosis were assessed after treatment with taxol. The results showed that p33ING1b markedly increased taxol-induced growth inhibition and apoptosis in p53+/+ U2OS cells, but not in p53-mutant MG63 cells. Moreover, ectopic expression of p33ING1b could obviously upregulate p53, p21WAF1 and bax protein levels and activate caspase-3 in taxol-treated U2OS cells. Taken together, our data demonstrate that p33ING1b enhances taxol-induced apoptosis through p53-dependent pathway in human osteosarcoma cells. p33ING1b may be an important marker and/or therapeutic target in the prevention and treatment of osteosarcoma.     

p53基因诱导胱癌细胞HTB9凋亡及相关基因的表达

目的 研究野生型p53基因诱导膀胱癌细胞凋亡的作用,及其对凋亡相关基因bcl-2、bax和ICE表达的调控。方法 将野生型p53基因重组腺病毒载体转染人膀胱癌细胞HTB9,应用RT－PCR检测bax的mRNA表达水平,应用免疫组化法检测bcl-2、bax和ICE蛋白表达水平,以DNA琼脂糖凝胶电泳、脱氧核苷酸转移酶介导的dUTP切口末端标记技术（TUNEL）和流式细胞仪检测细胞凋亡。结果 野生型p53基因导入可诱导HTB9细胞凋亡,凋亡细胞百分率可达50．4％;bax mRNA和蛋白水平增高,ICE和Bcl-2蛋白水平分别增高和下降。结论 野生型p53基因很可能是通过调控凋亡相关基因ICE、Bax和Bcl-2的表达来诱导细胞凋亡。     

内皮抑素抑制SKOV3细胞生长及其在裸鼠皮下移植瘤中的作用机制

目的:探讨内皮抑素对卵巢癌SKOV3细胞及其荷瘤鼠卵巢癌组织的生长作用及机制。方法:MTT法观测内皮抑素对体外SKOV3细胞的抑制作用,透射电镜观察细胞凋亡、免疫细胞化学检测SKOV3;细胞中bcl-2和bax蛋白表达;将SKOV3细胞移植至裸鼠皮下,观察内皮抑素对皮下移植瘤生长的影响;TUNEL和电镜法观察肿瘤细胞的凋亡,免疫组织化学和RT-PCR法检测瘤组织中bcl-2和bax的表达。结果:内皮抑素具有体外抑制SKOV3细胞增殖的作用(P<0．01);能诱导SKOV3细胞凋亡,但对bcl-2和bax的表达无明显影响。内皮以抑素能抑制裸鼠皮下移植瘤的生长(P<0．05);其中bcl-2的表达低于对照组,而bax表达无明显改变。结论:内皮抑素具有抑制SKOV3细胞及皮下移植瘤生长的作用,其机制可能与诱发细胞凋亡和调节bcl-2／bax表达相关。