GP_1对人肝癌细胞SMMC-7721细胞周期和端粒酶活性的研究

[目的]研究GP1 对人肝癌细胞细胞周期和端粒酶活性的影响 ,探讨其抗癌机制。[方法]以SMMC 7721细胞为研究对象 ,采用MTT法 ,流式细胞术和端粒重复序列扩增法。[结果]GP1 可抑制SMMC 7221细胞增殖 ;阻滞细胞从G2/M期进入G1 期 ;降低细胞端粒酶活性。[结论]GP1 阻滞细胞周期于G2/M期和降低端粒酶活性是其重要的抗癌机制     

冬凌草甲素对K562细胞端粒酶活性调控和细胞周期的影响

目的　目的 :研究冬凌草甲素 (ORI)对K5 62细胞端粒酶活性及其细胞周期的影响。方法　采用MTT法观察不同浓度ORI对K5 62细胞增殖的影响 :采用端粒重复序列扩增法 (TRAP) 酶联免疫吸附试验 (ELISA)法检测了端粒酶活性变化 ;采用流式细胞仪测定细胞周期各时相百分比。结果　ORI可明显抑制K5 62细胞增殖 ;在一定的浓度范围内 ,ORI可下调K5 62细胞端粒酶活性。流式细胞仪结果显示 ,经ORI处理的K5 62细胞 ,细胞周期各时相分布发生变化 ,G2 /M期细胞增多 ,S期细胞减少。结论　ORI可下调K5 62细胞的端粒酶活性 ,其机制可能与其细胞周期阻滞作用有关。     

顺铂和放疗对喉癌细胞端粒酶活性的诱导及其机制研究

 目的　观察 CDDP和放疗对喉癌细胞的端粒酶活性和细胞周期的影响 ,并探讨其机制。方法　 Hep- 2细胞经不同剂量的顺铂或60 Co- 射线处理。分别用流式细胞仪、端粒酶 PCR-ELISA法检测及聚丙烯酰胺凝胶电泳及银染法分析 CDDP和射线诱导的端粒酶活性和细胞周期的变化。结果　CDDP及放疗均能使 Hep- 2细胞的端粒酶活性明显上调 ,并表现为浓度依赖性。CDDP能蓄积 S期细胞 ,放疗阻滞 G2 /M期细胞。放化疗引起的端粒酶活性的上调与 S期细胞的百分比相关 ( r=0 .5371 ,b=7.8393)。结论　放化疗引起的端粒酶活性的变化与其对细胞周期的诱导有关.     

顺铂对人鼻咽癌CNE-2Z细胞端粒酶活性和细胞周期及凋亡的影响

目的研究顺铂对人鼻咽癌CNE-2Z细胞端粒酶活性、细胞周期及凋亡的影响,以探讨顺铂诱导CNE-2Z细胞凋亡与端粒酶活性水平的关系以及顺铂诱导鼻咽癌细胞凋亡的可能机制。方法分别以不同的药物浓度作用于体外培养的CNE-2Z细胞不同的时间,用TRAP-ELISA的方法定量检测CNE-2Z细胞在顺铂处理前后的端粒酶活性水平,同步进行细胞形态观察,流式细胞仪分析细胞周期的改变并检测凋亡。结果CNE-2Z细胞端粒酶呈阳性。用不同浓度的顺铂不同的时间作用于CNE-2Z细胞,结果细胞周期被阻滞在G1期,出现细胞凋亡,下调端粒酶活性,且呈时间依赖性及剂量依赖性。结论化疗药物顺铂可能是通过改变细胞周期分布(G1期阻滞)并同时诱导细胞凋亡、下调其端粒酶活性而发挥抗癌作用的,故可将化疗前后细胞端粒酶活性的变化作为鼻咽癌化疗敏感性指标之一。     

冬凌草甲素对K562细胞端粒酶活性调控和细胞周期的影响

目的 目的：研究冬凌草甲素(ORI)对K562细胞端粒酶活性及其细胞周期的影响。方法 采用MTT法观察不同浓度ORI对K562细胞增殖的影响：采用端粒重复序列扩增法(TRAP)．酶联免疫吸附试验(ELISA)法检测了端粒酶活性变化；采用流式细胞仪测定细胞周期各时相百分比。结果 ORI可明显抑制K562细胞增殖；在一定的浓度范围内，ORI可下调K562细胞端粒酶活性。流式细胞仪结果显示，经ORI处理的K562细胞，细胞周期各时相分布发生变化，G2／M期细胞增多，S期细胞减少。结论 ORI可下调K562细胞的端粒酶活性，其机制可能与其细胞周期阻滞作用有关。     

Z-ajoene引起HL-60细胞G2/M期阻滞及端粒酶表达活性的降低

目的 探讨Z-ajoene诱导细胞周期阻断于G2／M期的分子机制以及对端粒酶活性的抑制作用。方法 采用MTT法测定Z-ajoene对HL-60细胞的增殖抑制率;以流式细胞仪测定Z-ajoene对HL-60细胞的周期阻断作用,并采用Western blot法测定相关蛋白p34^cdc2、cyclinB1、cyclinA的表达水平;TRAP-银染法测定端粒酶活性的变化,同时采用RT-PCR方法检测端粒酶hTRT和TP1mRNA的表达。结果 10μmol／L Z-ajoene作用后能明显将HL-60细胞阻滞于G2／M期。在药物作用10h后,G2／M期细胞的比例达到顶峰,与对照组比较增加了1．95倍。另外,10μmol／L Z-ajoene作用后出现cyclinB1蛋白的聚集及p34^cdc2蛋白表达的降低,但cyclinA蛋白的水平并无显著性变化。经Z-ajoene作用24h后,HL-60细胞端粒酶活性显著降低。而不同浓度的药物作用12h,其端粒酶活性均无显著性变化。在10μmol／L Z-ajoene作用24h后,能够降低端粒酶hTRT和TP1 mRNA的水平。结论 Z-ajoene能够在作用较短时问内明显将细胞周期阻断于G2／M期,同时伴有cyclinB1聚集及p34^cdc2的抑制;而HL-60细胞的端粒酶活性仅在药物作用较长时间后才有一定降低,并且端粒酶hTRT和TP1mRNA的表达也同时降低。结果表明,Z-ajoene的细胞周期阻断作用可能是造成端粒酶缺失及HL-60细胞生长抑制的重要原因。     

顺铂对人肺腺癌细胞SLC-89作用的机理探讨

目的 观察顺铂对SLC-89细胞增殖生长、端粒酶活性、细胞周期、p53、bcl-2及增殖细胞核抗原(PCNA)表达的影响，探讨顺铂抗癌作用的机理。方法 以不同浓度的顺铂作用于培养的SLC-89细胞72h，运用MTT法测定细胞增殖，端粒酶重复序列扩增酶联免疫吸附法(TRAP-ELISA)检测细胞端粒酶活性以及流式细胞术观察细胞周期的变化和p53、bcl-2及PCNA的表达。结果 顺铂能显著抑制SLC-89细胞的生长，IC50为18．47mg／L。顺铂能以浓度依赖方式下调SLC-89细胞端粒酶活性，减少S期细胞而阻滞细胞于G0／G1期，降低bcl-2和PCNA的表达，同时诱导p53的表达。结论 顺铂能显著抑制SLC-89细胞生长增殖、改变细胞周期分布、降低端粒酶活性及bcl-2与PCNA的表达，并诱导p53的表达，这可能是顺铂抗癌作用的重要机理。     

康莱特对大肠癌HT-29细胞株体外生长抑制作用的研究

目的通过观察康莱特(K ang la ite,KLT)对大肠癌HT-29细胞株体外生长的抑制率、细胞周期及端粒酶活性影响,探讨其对大肠癌HT-29细胞株体外生长的抑制机制。方法(1)用M TT法检测康莱特在不同浓度及不同作用时间对大肠癌HT-29细胞株体外生长的抑制率。(2)碘化丙啶(P I)染色后用流式细胞术检测康莱特作用前后HT-29细胞周期分布。(3)用TRAP-PCR-EL ISA法检测康莱特作用前后HT-29细胞的端粒酶活性。结果在40、80μl/m l康莱特作用下HT-29细胞体外增殖及端粒酶活性明显受抑制,G2+M期百分比明显增高。细胞生长抑制率在72小时时分别为9.5%与37.1%,在120小时时分别为25.5%与48.0%。端粒酶活性在72小时时分别为1.127±0.043与1.046±0.035;120小时时分别为1.075±0.047与1.008±0.057,均低于空白对照组(P<0.05)。G2+M期百分比72小时时分别为23.9%与45.2%,空白对照组为7.2%(P<0.05)。结论(1)康莱特使体外生长的大肠癌HT-29细胞株阻滞于细胞周期的G2+M时相。(2)康莱特抑制HT-29细胞株端粒酶活性。(3)抑制作用呈时间和剂量依赖性。     

雌、孕激素对子宫内膜癌细胞端粒酶活性及细胞周期的影响

 目的　研究雌、孕激素对子宫内膜癌HHUA细胞端粒酶活性及细胞周期的影响。方法　用TRAP ELISA法和实时荧光定量PCR技术检测雌、孕激素作用前后HHUA子宫内膜腺癌细胞系端粒酶活性及hTERT RNA的表达 ,流式细胞仪检测细胞周期及细胞凋亡的变化。结果　雌激素对HHUA细胞端粒酶活性和hTERT的表达有明显增强作用 (P <0 .0 5 ) ,而孕激素对其影响不显著。孕激素作用下 ,G1期细胞比例明显增高 ,S期及G2 ～M期细胞比例明显降低 (P <0 .0 5 ) ;细胞的分裂、增殖受到明显抑制 ;凋亡细胞比例明显增加。雌激素的作用则相反。结论　雌激素能增强子宫内膜癌细胞端粒酶活性和hTERT的表达 ,促进其分裂和增殖 ,降低凋亡细胞比例 ,孕激素的作用相反     

Prognostic Significance of Inflammation-associated Blood Cell Markers in Nonmetastatic Clear Cell Renal Cell Carcinoma

ObjectivesOur objective was to evaluate the effect of the neutrophil/lymphocyte ratio (NLR), platelet/lymphocyte ratio (PLR), lymphocyte/monocyte ratio (LMR), and red blood cell distribution width (RDW) on the survival outcomes of nonmetastatic clear cell renal cell carcinoma (ccRCC).Materials and MethodsWe accessed our single-center, urologic-oncologic registry to extract the data for patients who had undergone nephrectomy for nonmetastatic ccRCC. The optimal cutoff for these markers was determined using X-tile software, and survival analyses using Cox regression were performed.ResultsA total of 687 patients had undergone nephrectomy. The optimal cutoffs for NLR, PLR, LMR, and RDW were 3.3, 210, 2.4, and 14.3%, respectively. The NLR, PLR, LMR, and RDW were significantly associated with a larger pathologic tumor size, and stage, more aggressive Fuhrman grade, and the presence of tumor necrosis. After adjusting for age, baseline Eastern Cooperative Oncology Group, pathologic tumor and nodal stage, and Fuhrman grade, only PLR remained an independent prognostic marker for both cancer-specific survival (hazard ratio, 2.69; 95% confidence interval, 1.36-5.33; P = .004) and overall survival (hazard ratio, 2.19; 95% confidence interval, 1.36-3.50; P = .001). When the PLR was included with the Leibovich score and University of California, Los Angeles, integrated staging system, the Harrell’s c-index increased from 0.854 to 0.876 and 0.751 to 0.810, respectively, for cancer-specific survival at 5 years after nephrectomy. When risk stratified by the Leibovich risk group and UCLA integrated staging system, PLR was a significant prognostic factor only within the intermediate- to high-risk groups.ConclusionsPLR is a robust prognostic marker in nonmetastatic ccRCC that clearly outperforms other inflammatory indexes in those who had undergone nephrectomy. However, its prognostic effect was limited in the low-risk category of ccRCC.     

Inhibition of Glioma Cell Proliferation by Neural Stem Cell Factor

Summary Neural stem cells (NSC) have unique differentiation-, proliferation-, and motility properties. To investigate whether they secrete factors that interfere with the proliferation of glioma cells, we grew glioma cells in conditioned medium (CM) obtained from cultures of neurospheres including neural stem / progenitor cells (NSPC) isolated from embryonic (E14)- or adult mouse brain or fetal human brain. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and BrdU-labeling assays showed that CM from NSPC (NSPC/CM) contained factor(s) that inhibited the proliferation of glioma cells by 28–87%. Filter-fractionation of NSPC/CM revealed that the 50,000–100,000 nominal molecular weight limit (NMWL) fraction contained the inhibitory activity. On the basis of these observations we transplanted 203G glioma cells and/or NSPC into the intrathecal space of the cisterna magna of mice to investigate whether NSPC interfere with the proliferation of glioma cells in vivo. Mice transplanted with both 203G and NSPC survived significantly longer than did mice transplanted only with 203G. We concluded that NSPC secrete factor(s) that may control glioma cell proliferation.     

High Occurrence of Non-Clear Cell Renal Cell Carcinoma in Oman

It is conventionally accepted that renal cell carcinoma (RCC) occurs in older patients and the clear cell type is the most common histology. However, ethnic variations exist and this study was carried out to determine the epidemiological pattern of RCC in Oman. Ninety RCC patients who presented to a tertiary care center in the Sultanate of Oman from 2010 to 2014 were studied. The main findings were that the median age of presentation was low, more patients presented with localized stage, and there was a higher incidence of non-clear (especially papillary) histology. Data from other Gulf countries and possible reasons for the different profile are discussed.     

Inhibition of Natural Killer Cell Cytotoxicity by Cell Growth-related Molecules

Certain MHC class I molecules on target cells are known to inhibit the cytotoxic action of NK cells. By using monoclonal antibody (mAb) Cho-1, we have found inhibitory non-MHC class I cell surface molecules that are noncovalently-associated with 200 kDa and 40 kDa antigens. Poly I-C-induced rat NK cells were not cytotoxic to rat fetus-derived fibroblast WFB cell line. In contrast, NK cells were cytotoxic to H- ras oncogene-induced transformants of WFB, W14 and W31. FACS analysis indicated that mAb Cho-1 reacts with WFB, but not with W14 and W31 cells. Thus, this antigen may disappear concomitantly with cell growth and transformation. Cho-1 antigens were also expressed on other NK-resistant lines, such as mouse BALB3T3 fibroblast, EL-4 lymphoma and human fibroblast HEPM. However, they were not expressed on NK-sensitive mouse YAC-1 and H- ras transformant (Brash) of BALB3T3 cells. Furthermore, treatment of target cells with IFN-γ clearly induced the cell surface expression of Cho-1 antigens, and conferred a resistance to NK cytolysis on target cells. These data strongly suggest that Cho-I antigen expression may correlate with target cell susceptibility to NK cells. Indeed, treatment of NK-resistant WFB as well as HEPM cells with F(ab')₂ fragments of mAb Cho-1 resulted in the acquisition of susceptibility to NK cytolysis. Cho-1 antigens may be novel molecules that regulate the NK resistance of cells.     

人干扰素对HL60,K562细胞生长及细胞周期的影响

用人干扰素(α和γ)与HL60、K562细胞共同培养后,对细胞生长有不同程度抑制作用。IFN_r对细胞生长抑制作用强于IFN_r,IFN_r和IFN_r联合应用有协同作用,在K562细胞,细胞在细胞周期中的分布也发生改变,G_0/G_1期细胞比例减少,S期细胞比例增高,在HL60细胞则无明显的细胞周期再分布情况。提示细胞在S期的堆积是细胞生长受抑的原因之一。     

Cell kinetics

Cell kinetic concepts have pervaded radiation therapy since the early part of the 20th century and have been instrumental in the development of modern radiotherapy. In this review, the fundamental radiobiological concepts that have been developed based on cell kinetic knowledge will be revisited and discussed in the context of contemporary radiation therapy. This will include how the proliferation characteristics, variation in sensitivity during the cell cycle and the extent of radiation-induced cell cycle delay translate into a variable time for the expression of damage, how cell kinetics interacts with hypoxia and how the response to fractionated radiation schedules is influenced by cell kinetics in terms of repair, redistribution, reoxygenation and repopulation. The promise of combining radiation with new biologically targeted agents and the potential of non-invasive positron emission tomography imaging of proliferation are areas where cell kinetics will continue to influence radiotherapy practice.     

Expressions of Cell Cycle Regulators in Human Colorectal Cancer Cell Lines

To study the altered mechanisms of cell cycle regulation in colorectal cancer, the expressions of cyclins, cyclin-dependent kinases (CDKs), CDK inhibitors, p53 and retinoblastoma (Rb) protein were analyzed by western blotting in a series of human colorectal cancer cell lines. The colorectal cancer cell lines exhibited various expression patterns of cell cycle regulators, which may reflect differences in the biological characteristics of cancer cells and in the genetic backgrounds of carcinogenesis. A correlation was found between p53 gene alteration and p21 expression, suggesting that p53 gene mutation usually suppresses p21 expression, though p21 expression could be induced via both ap53 -dependent and a p53 -independent pathway in colorectal cancer. None of the cell lines studied expressed p16 protein, suggesting that inactivation of p16 may be a common alteration in colorectal cancer. Moreover, all the D-type cyclins, especially D2 and D3, were expressed at a high level in most of the cell lines. Loss of p16 expression and increased expression of D-type cyclins promote CDK-mediated Rb phosphorylation. All of the colorectal cancer cell lines studied herein expressed Rb protein, but the growth-suppressive properties of Rb may be inactivated by the loss of p16 expression and increased expressions of D-type cyclins. In view of the pivotal role of Rb in cell cycle regulation, loss of p16 expression and overexpression of D-type cyclins may be critical alterations in colorectal cancer.