细胞周期基因芯片筛选不同增殖状态下CNE-2细胞的差异表达基因

目的:了解不同增殖状态鼻咽癌细胞(CNE-2)细胞周期基因表达差异,探讨鼻咽癌放射治疗中加速再增殖的机理.方法:对不同增殖状态的CNE-2细胞,采用基因芯片技术、实时荧光定量PCR检测其细胞周期相关基因表达差异.结果:细胞增殖活性最高时相(2Gy连续照射第3天)与最低时相(2Gy连续照射第5天)表达有差异的基因有3条,为检测基因总数的3%(3/100),其中细胞增殖活性增高时上调基因为CCNE1、CUL-5,下调基因为CDKNlA.应用相对定量荧光实时PCR技术对部分差异表达在2倍以上的基因(CCNE1、CDKNIA))进行了mRNA水平的验证,结果显示实时PCR实验结果与芯片结果具有良好的一致性.结论:某些细胞周期基因如CCNE1、CUL-5、CDKN1A等可能参与了鼻咽癌放射治疗过程中发生的加速再增殖过程,有必要对这些基因功能作进一步研究,以探明照射过程中肿瘤细胞加速再增殖发生的分子机制.     

不同增殖状态下CNE-2细胞株DNA损伤修复相关基因表达差异的观察

目的:了解不同增殖状态鼻咽癌细胞(CNE-2)基因表达差异,探讨鼻咽癌放射治疗中加速再增殖的机制.方法:对不同增殖状态的CNE-2细胞,采用基因芯片技术、实时荧光定量PCR检测其DNA损伤修复相关基因的表达差异.结果:CNE-2细胞增殖活性最高时相(2 Gy连续照射第3天)与最低时相(2 Gy连续照射第5天)表达有差异的DNA损伤修复相关基因6条,占检测基因总数的5.9%(6/102),其中细胞增殖活性增高时上调基因为CDC25A,下调基因为DDIT3、GADD45、CDKN1A、BNIP3和FOXO3A.应用相对定量荧光实时PCR技术,对部分差异表达>2倍的基因(CCNE1、CDC25A、CDKN1A、DDIT3、GADD45和BNIP3)进行了mRNA水平的验证,结果显示实时PCR实验结果与芯片结果具有良好的一致性.结论:DNA损伤修复的某些基因如CDC25A、CDKN1A、DDIT3、GADD45、BNIP3和FOXO3A等可能参与了CNE-2细胞放射治疗过程中发生的加速再增殖过程,加速再增殖可能是一个复杂的、多基因协同作用的结果.     

鼻咽癌细胞株CNE-2连续照射期间细胞增殖状况的研究

目的：了解鼻咽癌细胞（CNE-2）照射过程中的增殖情况，探讨鼻咽癌放射治疗巾加速再增殖的时机，为临床上进行鼻咽癌后程加速超分割放射治疗提供理论依据。方法：对接受^60Co-γ射线2Gy／天，每天1次，连续照射5天期间的CNE-2细胞，每天分别采用四氮唑兰比色分析法（MTT法）检测CNE-2细胞仔活率、细胞分裂指数法检测细胞分裂指数、流式细胞术检测照射后细胞周期分布情况。结果：MTT法、细胞分裂指数法和流式细胞术均检测出CNE-2细胞在连续照射的第3天增殖速度最快，增殖最旺盛；在第5灭细胞增殖速度最缓慢，增殖活性最低。结论：鼻咽低分化鳞癌细胞连续分割照射中后期存在加速增殖现象。     

沉默CDKN1A基因对鼻咽癌放射抗拒性CNE-2R细胞放射敏感性的影响

目的：探讨CDKN1A基因的表达与鼻咽癌放射敏感性的关系。方法构建慢病毒表达载体LV-CDKN1A-RNAi并转染鼻咽癌放射抗拒性CNE-2R细胞,设转染LV-CDKN1A-RNAi慢病毒的CNE-2R细胞为实验组,转染阴性对照慢病毒的CNE-2R细胞为阴性对照组,未转染的CNE-2R细胞为空白对照组。用CCK-8法、细胞克隆形成实验及流式细胞术分别检测各组细胞增殖、放射敏感性及细胞周期的变化。结果成功构建了CDKN1A基因沉默的CNE-2R细胞,CCK-8法检测显示实验组CNE-2R细胞在照射6 Gy后生长受到抑制,且随时间延长其抑制作用更为明显。细胞克隆形成实验显示实验组CNE-2R细胞放射敏感性增强（放射增敏比为SER=1.24）。流式细胞术检测显示实验组与对照组细胞相比, G0/G1期和G2/M期细胞分布在X射线照射6 Gy前后明显改变（P约0.05）。结论 CDKN1A基因沉默能增强鼻咽癌放射抗拒性CNE-2R细胞的放射敏感性,CDKN1A基因的表达可能与鼻咽癌放射敏感性相关,有望成为鼻咽癌治疗的新靶点。     

X线照射后对乳腺癌细胞凋亡的影响及CDKN1A表达的变化

目的探讨乳腺癌细胞系（MCF-7）X线照射后CDKN1A基因（p21）表达变化及其对细胞凋亡的影响。方法用流式细胞方法检测MCF-7细胞在接受不同剂量X射线照射后CDKN1A基因表达的改变和用RNAi技术抑制CDKN1A基因表达并检测细胞凋亡的变化。结果MCF-7细胞在接受不同剂量（1、2和4 Gy） X射线照射后CDKN1A蛋白表达有不同程度升高,其中 4 Gy照射后升高水平最明显（P<0.05）。在接受4 Gy剂量照射后,CDKN1A蛋白水平在8、12、24、48、72 h 均有不同程度增加,其中24 h时较对照组升高3倍(P<0.05)。抑制CDKN1A基因表达后MCF-7细胞凋亡率增加183.9%（P<0.05）。结论乳腺癌细胞在接受4 Gy照射后24 h的CDKN1A表达水平增加最为明显,抑制CDKN1A基因表达可促进细胞凋亡。     

^60Co分割照射对鼻咽癌细胞生长增殖影响的观察

目的：观察不同剂量60Coγ射线分割照射对鼻咽癌细胞株CNE-2细胞生长和细胞周期素（Cyclin）D1及增殖细胞核抗原（PC-NA）的影响。方法：0、2.0、4.0、6.0Gy60Coγ射线分割照射CNE-2细胞1次/d,共5d。四唑盐（MTT）比色法测定细胞抑制率;流式细胞术检测细胞周期。PCR检测PCNA和Cyclin D1表达水平。结果：2.0、4.0、6.0Gy60Coγ射线分割照射5次/5d后各组细胞生长抑制率分别为-17.05%、4.01%和15.52%;各照射组G1期细胞数量减少,S＋G2/M期细胞数比例增多,χ2=16.53,P〈0.001。0、2.0、4.0、6.0Gy60Coγ射线分割照射CNE-2细胞5次/5d,CyclinD1表达水平随照射分割剂量增加而下降直至不表达,P值分别为0.035、0.022和0.000。2.0Gy照射CNE-2细胞5次/5d,细胞生长增殖未受到抑制,PCNA表达无下调,P=0.471;4.0和6.0Gy照射CNE-2细胞5次/5d,细胞生长增殖受到抑制,PCNA表达下调,P值分别为0.028和0.016。结论：4.0、6.0Gy60Coγ射线分割照射5次/5d,细胞生长增殖受到抑制;2.0Gy照射5次/5d细胞生长增殖未受抑制;2.0、4.0、6.0Gy60Coγ射线分割照射5次/5d后,CyclinD1和PCNA表达受抑制。     

DNA-PKcs 表达与鼻咽癌细胞株放射敏感性的关系

 目的 探讨不同放射敏感性鼻咽癌细胞株CNE-1（鼻咽高分化鳞癌细胞株）和CNE-2（鼻咽低分化鳞癌细胞株）中DNA依赖蛋白激酶（DNA-PK）的催化亚基DNA-PKCS基因的表达与鼻咽癌细胞放射敏感性的关系。方法 通过克隆形成实验测定CNE-1、CNE-2不同剂量的存活分数，并用线性二次模型拟合剂量存活曲线求出放射生物学参数α、β,SF2、MID值，以及四氮唑蓝比色分析法（MTT法）检测60Co-γ线4Gy照射后12h细胞的存活率，以评价两株细胞的放射敏感性。逆转录实时荧光定量PCR技术（RTrFQPCR）检测照射前、后不同时间及不同剂量CNE-1、CNE-2细胞mRNA水平DNA-PKCS基因的定量表达。结果CNE-1在各个剂量点的存活分数均比CNE-2高，MID值分别为2．78、1．61，SF2值分别为0．627、0．341；4Gy照射后12h的存活率分别为88．2％、72．3％；RT-FQPCR显示两株细胞中均有DNA-PKCS基因的表达，其相对表达量之比为7．54±2．71（t=4．17，P=0．014），表达差异有统计学意义，DNA-PKCS基因在CNE-2细胞中存在时间、剂量依赖关系。结论实验验证了CNB2比CNE-1对射线更敏感，DNA-PKCS基因的表达与鼻咽癌细胞的放射敏感性有关。     

健择对人鼻咽癌细胞系放射增敏机制的实验研究

目的：观察单纯放射及放射联合健择（gemcitabine）对人鼻咽癌细胞系（CNE-2）细胞周期改变的影响，探讨健择对CNE-2细胞的放射增敏机制。方法：用流式细胞仪技术分析^60Coγ射线单纯照射和照射联合健择对CNE-2细胞周期的影响。结果：单纯照射导致CNE-2细胞G1期阻滞，照射剂量〈6Gy时与照射剂量呈正相关，〉6Gy时G1期阻滞基本稳定在一定水平。5mg／L、10mg／L、15mg／L健择与CNE-2细胞共育24h后照射2Gy，以S期阻滞为主；随着单次照射剂量的提高，以G1阻滞明显。CNE-2细胞与健择15mg／L共育12h后照射2Gy，开始时以G1阻滞为主，但24h后以S期阻滞明显。且至少维持36h以上。结论：健择对CNE-2细胞有中度放射增敏作用；其机制可能与健择引起S期或G1期阻滞有关。     

2Gy多分割不同顺序照射对鼻咽癌CNE-2细胞生物效应的研究

目的探讨总剂量为2 Gy时部分分割和顺序照射对鼻咽癌CNE-2细胞的杀伤效应的差异。方法采用克隆形成法和四唑盐（MTT）比色法,检测2 Gy剂量照射后鼻咽癌CNE-2细胞的细胞生存率和具有代谢活性细胞比例。结果在多个等分割照射中,较小分割（≤0.5 Gy）多次照射的细胞存活率均明显低于单次照射组（2 Gy）,差异有统计学意义（P〈0.05）,而较大分割（1 Gy）照射与单次照射组细胞生存率差异无统计学意义;在2个部分分割和3个部分分割照射中,随着S分割剂量的增大,各S-L和S-S-L照射组细胞生存率呈逐渐下降趋势,至S分割为0.4 Gy（S-L）或者0.5Gy（S-S-L）组时细胞生存率最低;大部分S-L照射组细胞生存率明显低于L-S照射组,大部分S-S-L照射组细胞生存率和相对细胞生存率明显低于L-S-S照射组,差异有统计学意义（P〈0.05）。结论总剂量为2 Gy照射时,分割剂量大小和照射顺序是影响鼻咽癌CNE-2细胞放射治疗生物效应的重要因素。     

下调VEGF表达影响鼻咽癌细胞放射敏感度的机制

目的　应用RNA干扰技术抑制人鼻咽低分化鳞状上皮细胞癌细胞株CNE-2中血管内皮生长因 子（VEGF）表达,研究阻断VEGF基因表达对鼻咽癌细胞放射敏感度的影响及机制。方法 构建针对 VEGF的siRNA真核表达载体pU-VEGF-siRNA（CNE-2组）、1个阴性对照质粒（CNE-2/Neg-siRNA 组）、经脂质体转染至CNE-2细胞（CNE-2/VEGF-siRNA组）,用平板克隆形成实验检测在6MV-X线 0、2、4、6、8、10 Gy照射后克隆形成能力及通过单击多靶模型、线性二次模型拟合放射生物学参 数,流式细胞检测分析细胞周期和细胞凋亡的变化,用RT-PCR定量分析三组细胞中Cyclin D1、Cyclin E、P16和P53的mRNA表达。结果 经6MV-X线0、2、4、6、8、10 Gy照射后细胞存活率显著下降, CNE-2/VEGF-siRNA组细胞经D0和2 Gy照射后的存活分数明显低于CNE-2组、CNE-2/Neg-siRNA组; CNE-2/VEGF-siRNA组中G1/S期细胞周期阻滞更为明显。在Cyclin D1、Cyclin E、p16和p53基因中, Cyclin D1mRNA表达在放疗后6、12和24 h进行性升高,差异有统计学意义,而其他基因变化差异无统 计学意义,Western blot检测显示Cyclin D1蛋白表达在放疗后24 h明显升高。结论 下调VEGF表达可 增加鼻咽癌细胞的放射敏感度,其机制可能是通过Cyclin D1信号通路途径使细胞周期发生G1/S期阻滞。     

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。     

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.     

内皮细胞特异性分子1在肾癌组织的表达

[目的]探讨内皮细胞特异性分子1(ESM-1)在肾癌中的表达及其意义.[方法]应用免疫组织化学S-P法检测52例肾癌、32例癌旁正常肾组织中ESM-1的表达,并与CD34进行比较.[结果]ESM-1在正常肾组织与肾癌中均有表达.主要表达于血管内皮,部分表达在肾小管上皮和肾癌细胞.肾癌血管内皮的ESM-1表达率(50%)显著高于正常肾组织的血管内皮(0.06%)(p<0.001);ESM-1 f的表达在正常肾小管上皮细胞与癌细胞无显著差异;ESM-1在肾颗粒细胞癌中的高表达率为63.16%,明显高于在肾透明细胞癌中的表达(21.21%)(p<0.01),而与肿瘤的组织学分级、淋巴结转移和肿块大小无明显差异.肾癌间质血管ESM-1和CD34的表达呈正相关(r=0.452,P＜0.001).[结论]ESM-1表达可能与肾癌的血管生成及发生、发展有关,ESM-1可作为血管内皮的潜在标志物,并有可能作为肾癌的辅助诊断及预后判断的参考指标.     

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.