细胞周期调控因子在大肠癌病变中的表达及临床意义

目的探讨细胞周期调控因子Cyclin D1、CDK4、P16蛋白及p16基因表达与大肠癌的临床病理特征及预后的关系.方法应用免疫组织化学SP法检测12例正常大肠黏膜和89例大肠癌组织中CyclinD1、CDK4、P16蛋白的表达并进行术后随访,对其中40例大肠癌组织进行p16基因SSCP-PCR分析,评估CyclinD1、CDK4、P16蛋白及p16基因表达与大肠癌组织学分级、临床Dukes分期、淋巴结转移及术后生存率的关系.结果大肠癌组织CyclinD1蛋白阳性标记位于癌细胞核,P16和CDK4位于细胞浆和细胞核,正常大肠黏膜未见Cyclin D1表达,P16和CDK4仅在细胞浆内表达.大肠癌组织中Cylin D1表达率为42.69%;P16胞浆表达率为57.30%,其中同时有核表达者为47.19%;CDK4胞浆表达率为92.13%,其中同时有核表达者为24.72%.正常大肠黏膜P16和CDK4表达率分别为25.00%和41.66%,明显低于大肠癌组织的表达(P＜0.05).大肠癌组织CyclinD1表达与淋巴结转移、患者术后生存率有明显的关系(P＜0.05),与临床分期、组织学分级相关性不显著(P＞0.05).CDK4核表达与组织学分级有关(P＜0.05),与临床分期和淋巴结转移及生存率的相关性不显著(P＞0.05).CDK4胞浆表达、P16胞浆表达和P16核表达与临床分期、组织学分级、淋巴结转移及生存率的相关性不显著.Cyclin D1、CDK4、P16三者在核区阳性表达有相关性.p16基因缺失率为47.50%,与组织学分级有关(P＜0.05),p16基因与P16蛋白表达呈正相关(P＜0.05).结论大肠癌组织Cyclin D1阳性表达与淋巴结转移关系密切,提示患者的预后较差,尤其对Dukes B期患者的预后评估有重要意义.大肠癌细胞分化程度与p16基因缺失及CDK4核阳性表达有一定关系.细胞周期调控因子Cyclin D1/CDK4/P16对细胞的异常调控可能是发生大肠癌的原因之一.     

Cyclin D1、P53和CDK4蛋白与胰腺癌的相关性

目的:研究细胞周期蛋白D1(Cyclin D1)、P53蛋白和细胞周期蛋白依赖性激酶4(CDK4)在胰腺癌中的表达差异,阐明其与胰腺癌的相关性.方法:兰州大学第一医院和定西地区医院1997-07/2004-01手术切除胰腺癌患者48例,术后标本均经病理证实.采用免疫组化SP法检测Cyclin D1、P53和CDK4在胰腺癌患者不同临床指标下的表达水平.结果:胰腺癌不同性别、年龄分组中CyclinD1、P53与CDK4的阳性表达率均无显著差异.在低分化、有淋巴结转移、临床分期Ⅲ,Ⅳ期的胰腺癌组织中Cyclin D1和CDK4的阳性表达率明显高于高分化、无淋巴结转移、临床分期Ⅰ,Ⅱ期的胰腺癌中的阳性表达率(Cyclin D1:χ2=10.540,14.225,5.043,P<0.01或0.05;CDK4:χ2=7.619,4.006,5.581,P<0.05).有淋巴转移的胰腺癌组织中P53的阳性表达率明显高于无淋巴转移的组中的阳性表达率(χ2=6.146,P<0.05);而不同分化程度和临床分期的胰腺癌组织中P53的表达无明显的差异性.结论:Cyclin D1可以作为早期诊断胰腺癌的生物学指标,而P53和CDK4在胰腺癌的发生、发展过程中起重要的协同作用.     

耐药乳腺癌细胞细胞周期分析及调控异常的研究

目的 分析耐药乳腺癌细胞细胞周期及细胞周期调控异常特点.方法 用流式细胞仪分析耐药乳腺癌细胞的细胞周期特点,运用相应的抗体通过蛋白电泳及Western 印迹检测Cyclin E、A,P21/WAF1和CDK2在耐药乳腺癌细胞中的表达.结果 细胞周期为S期的细胞明显增加,而G1期细胞减少,G2/M期变化不明显.耐药细胞中Cyclin E、CDK2、P21/WAF1蛋白质的表达升高,Cyclin A无明显变化.结论 S期细胞增加是耐药乳腺癌细胞细胞周期改变特点,Cyclin E、 P21/WAF1和CDK2共同参与了耐药乳腺癌细胞S期的调控.     

P21~(ras)、P16在大肠癌中的表达及临床意义

目的探讨癌基因P21~(ras)及抑癌基因P16与大肠癌的关系。方法应用免疫组化SP法分析、研究了P21~(ras)蛋白、P16蛋白在80例大肠癌、20例大肠腺瘤及20例正常大肠组织中的表达。结果①P21~(ras)在前二者中的阳性表达率分别为70.1％(57/80)和65％(13/20),明显高于在正常组织中的30％(6/20),其比较具有显著性差异(x~2=17.66、P<0.005;x~2=5.23、P<0.05);P16在大肠癌中的阳性表达率为36.3％(29/80)低于在腺瘤及正常组织中的65％(13/20)和75％(15/20),其比较亦具有显著性差异。②P21~(ras)、P16的阳性表达率在大肠癌患者的年龄、性别及肿瘤大小方面无显著性差异,而与肿瘤的临床Dukes分期(x~2=6.20、P<0.025;x~2=6.25、P<0.05)、有无淋巴结转移及术后5a生存率密切相关。③P21~(ras)在不同的大肠癌组织病理类型中,其表达率无显著性差异;P16的阳性表达率随着肿瘤浸润深度的增加有下降趋势,但无统计学意义。④在80例大肠癌患者中,P21~(ras)阳性而P16阴性者比率高于其他三者,而且这类大肠癌患者的术后5a生存率下降。结论大肠癌的发生、发展,是由包括癌基因、抑癌基因在内的多种因素作用的结果;在临床工作中联合检测P21~(ras)及P16蛋白在大肠癌中的表达水平,对我们估计患者的病情、推测其预后有指导性意义。     

Cyclin B1、CDK1在食管鳞癌组织中的表达及临床意义

目的: 探讨食管鳞癌组织中细胞周期蛋白Cyclin B1和细胞周期蛋白依赖性激酶CDK1表达及其临床病理学意义.方法: 应用免疫组织化学SP法对52例食管鳞癌(组织学Ⅰ级8例, Ⅱ级20例, Ⅲ级24例;有淋巴结转移20例, 无淋巴结转移32例;原位癌16例, 侵袭性癌36例包括浸润至黏膜下层、肌层、全层)及其配对的癌旁正常组织进行Cyclin B1、CDK1的检测, 分析其阳性表达与食管鳞癌患者临床病理因素的关系.结果: 食管鳞癌组织中Cyclin B1、CDK1的阳性表达高于癌旁正常食管黏膜组织, 2组差异都有统计学意义(71.2% vs 2.0%, 65.4%vs 3.9%, 均P <0.05). 食管鳞癌组织中CyclinB1、CDK1的表达都与性别、年龄无关;与组织学分级、浸润深度及淋巴结转移有关(均P <0.05). Cyclin B1阳性表达强度与CDK1的阳性表达强度之间呈正相关(r = 0.697, P <0.05) .结论: Cyclin B1、CDK1的高表达会促进食管鳞癌的发生与发展. 而且食管鳞癌中CyclinB1与CDK1的表达密切相关, 可作为食管鳞癌生物学行为预测的参考指标.     

CyclinB2、CDK1在胃癌中的表达水平及生物学意义

目的探讨胃癌患者瘤组织中细胞周期蛋白(Cyclin)B2、细胞周期依赖性激酶(CDK1)的表达水平及其预后的临床生物学意义。方法共收集60例胃癌患者组织标本,采用免疫组化法检测胃癌及癌旁组织Cyclin B2、CDK1表达水平进而分析其与患者临床病理特征及长期预后的相关性。结果胃癌组织Cyclin B2、CDK1表达水平明显高于癌旁组织(χ2=17.515,P<0.001),病理为Ⅲ期患者的瘤组织中Cyclin B2、CDK1的表达水平明显高于术后病理Ⅰ期,临床统计学证实Cyclin B2、CDK1的表达水平与TNM分期有关(χ2=11.545,P=0.05)。Cyclin B2、CDK1高表达的胃癌患者总生存率明显差于Cyclin B2、CDK1低表达者(P=0.039),而无疾病生存率两者无显著性差异(P=0.096)。结论胃癌患者Cyclin B2、CDK1高表达可能提示肿瘤侵袭的生物学能力较强,并与患者低总生存率(OS)有关。     

PHB1对人肝癌细胞增殖的影响及其作用机制

目的探讨抗增殖蛋白1(prohibitin1,PHB1)对人肝癌细胞增殖的影响及其作用机制。方法构建PHB1真核表达重组质粒(pEGFP-PHB1)和PHB1靶向siRNA质粒(shRNA-PHB1)转染人肝癌细胞HepG2和SMMC-7721,诱导PHB1在人肝癌细胞中表达上调和下调,采用MTT、流式细胞学、荧光定量PCR和免疫印迹等技术检测人肝癌细胞增殖、细胞周期,以及细胞周期关键调控分子的表达情况。结果高表达PHB1可阻滞HepG2和SMMC-7721细胞于G0/G1期[(67.28±2.94)%比(56.71±2.56)%,t=6.64,P=0.00;(69.48±3.82)%比(60.43±2.59)%,t=4.80,P=0.00],使S期比例下降[(14.74±1.45)%比(24.13±1.92)%,t=9.54,P=0.00;(13.73±1.26)%比(25.50±2.30)%,t=10.99,P=0.00],抑制细胞增殖;周期调控分子p53和p21CIP1mRNA和蛋白质水平显著升高,而Cyclin A2、Cyclin E1和CDK2 mRNA和蛋白质水平显著降低(P0.01)。低表达PHB1可促使HepG2和SMMC-7721细胞趋于S期[(31.65±2.71)%比(24.68±1.28)%,t=5.69,P=0.00;(31.02±2.49)%比(25.88±2.40)%,t=3.64,P=0.005],促进细胞增殖;p53、p21CIP1、Cyclin A2、Cyclin E1、CDK2 mRNA和蛋白质水平与PHB1高表达时相反(P0.01)。结论高表达PHB1可以阻滞人肝癌细胞周期于G0/G1期,进而抑制细胞增殖,其作用机制可能与p53介导的G0/G1期相关细胞周期蛋白有关。     

灵芝多糖抗H2O2诱导的HDF细胞衰老及其机制的研究

目的 探讨不同剂量灵芝多糖(GLP)对抗H2O2诱导的HDF细胞衰老及可能的细胞周期调控机制.方法 将HDF细胞培养至24代时分成6组:即青年组、对照组、衰老模型组及GLP小剂量(50 mg/L)、中剂量(100 mg/L)、大剂量(150 mg/L)组,体外DMEM培养,各GLP组和衰老模型组自30代始添加 H2O2诱导HDF细胞衰老,直至38代.采用MTT法检测细胞活力;Dimri法检测β-半乳糖苷酶活性;RT-PCR法检测p16INK4a、CyclinD1、CDK4的表达;Western印迹法检测Rb蛋白表达和磷酸化Rb.结果 与青年组及对照组比较,衰老模型组细胞活力下降(P＜0.01),β-半乳糖苷酶活性升高(P＜0.01),CyclinD1 mRNA表达升高(P＜0.01),CDK4 mRNA表达下降(P＜0.01),p16INK4a表达升高(P＜0.01),Rb磷酸化减少(P＜0.01);与衰老模型组细胞比较,中剂量和大剂量GLP细胞活力明显提高(均P＜0.01),而β-半乳糖苷酶活性降低(均P＜0.01),CyclinD1 mRNA表达降低(均P＜0.01),CDK4 mRNA表达升高(均P＜0.01),p16INK4a表达降低,Rb磷酸化增多(均P＜0.01),但两组之间差异无统计学意义(均P＞0.05).结论 GLP可通过改变细胞周期调控因子CyclinD1/CDK4/p16INK4a进而调节Rb的磷酸化状态,发挥抗H2O2诱导的HDF细胞衰老作用.     

大肠癌中胃泌素、生长抑素mRNA的表达与细胞凋亡及Bcl-2、Bax的关系

目的:探讨大肠癌组织中胃泌素(GAS)、生长抑素(SS) mRNA及蛋白的表达与大肠癌细胞凋亡指数(AI)和 Bcl-2、Bax的相关性．方法:采用巢式RT-PCR方法检测62例大肠癌组织中 GAS、SS的基因表达,用TUNEL法检测细胞凋亡情况, 大肠癌组织中GAS、SS、Bcl-2、Bax的蛋白表达采用免疫组织化学S-P法. 结果:大肠癌组织中GAS、SS mRNA的表达与其蛋白表达基本一致．在大肠癌组织SS高表达组、中表达组的AI明显高于SS低表达组(q=5．06,q=3．95, 均P<0．01);而在GAS各表达组中的AI变化与此相反 (q=:6．66,q=6．33,均P<0．01)．Bax、Bcl-2阳性表达率在SS和GAS低表达组、中表达组、高表达组三组间相比较存在着明显差别(x2=9．24,x2=6．91; x2=7．17,x2=13．83,均P<0．05),其中Bax在SS高表达组(80％,8／10)、中表达组(76．5％,13／17)的阳性表达率明显高于低表达组(40．0％,14／35)(x2=5．24,x2= 6．09,均P<0．05);Bcl-2与其相反(x2=4．71,x2=4．70,均 P<0．05)．Bcl-2在GAS高表达组(90．9％,10／11)、中表达组(86．7％,13／15)的阳性表达率明显高于低表达组 (44．4％,16／36)(x2=5．60,x2=7．69,均P<0．05);Bax 在GAS高表达组(27．3％,3／8)的阳性表达率明显低于低表达组(69．4％,25／36)(x2=4．59,P<0．05);而Bax 在GAS中表达组(46．7％,7／15)的阳性表达率低于低表达组,但其无明显差别．GAS／SS积分比值变化与 Bcl-2呈正相关(r=0．34,P<0．01),与AI、Bax呈负相关 (r=-0.546,P<0．01;r=-0．299,P<0．05)．结论:GAS、SS对大肠癌细胞凋亡的调控可能与 Bcl-2、Bax的异常表达有关．     

大肠癌组织中Cyclin E、p27kipl和Ki-67的表达及意义

目的 采用免疫组化PowerVision两步法检测137例大肠癌及其邻近正常黏膜组织中细胞周期素E(Cyclin E)、抑制因子p27kipl和核抗原-67(Ki-67).结果 :大肠癌组织中Cyclin E表达水平显著高于邻近正常黏膜组织,并与原发肿瘤浸润深度、区域淋巴结转移及TNM分期显著正相关(r分别为0.213、0.367、0.348,P均＜0.05).大肠癌组织中p27kipl表达水平显著低于邻近正常黏膜组织,并与原发肿瘤浸润深度、区域淋巴结转移及TNM分期显著负相关(r分别为-0.345、-0.269、-0.348,P均＜0.01).大肠癌组织中Ki-67表达水平显著高于邻近正常黏膜组织,并与区域淋巴结转移及TNM分期呈显著的正相关(r分别为0.218、0.172,P＜0.05).大肠癌组织中Cyclin E与p27kipl表达水平显著负相关(r=-0.235,P＜0.01);Cydin E和Ki-67表达水平显著正相关(r=0.243,P＜0.01);大肠癌组织中p27kipl与Ki-67表达水平呈显著负相关(r=-0.172,P＜0.01).认为Cyclin E和p27kipl是大肠癌发生及侵袭转移的正、负性因子,联合检测Cyclin E、p27kipl和Ki-67有助于判断大肠癌的生物学行为及预后判断.     

Correlation between the expressions of gastrin, somatostatin and cyclin and cyclin-depend kinase in colorectal cancer

AIM: To explore the correlation between the expressions of gastrin (GAS), somatostatin (SS) and cyclin, cyclin-dependent kinase (CDK) in colorectal cancer, and to detect the specific regulatory sites where gastrointestinal hormone regulates cell proliferation. METHODS: Seventy-nine resected large intestine carcinomatous specimens were randomly selected. Immunohistochemical staining for GAS, SS, cyclin D1, cyclin E, cyclin A, cyclin B1, CDK2 and CDK4 was performed according to the standard streptavidin-biotin-peroxidase (S-P) method. According to the semi-quantitative integral evaluation, SS and GAS were divided into high, middle and low groups. Cyclin D1, cyclin E, cyclin A, cyclin B1, CDK2, CDK4 expressions in the three GAS and SS groups were assessed. RESULTS: The positive expression rate of cyclin D1 was significantly higher in high (78.6%, 11/14) and middle GAS groups (73.9%, 17/23) than in low GAS group (45.2%, 19/42) (P<0.05, x2high vs low = 4.691; P<0.05, x2middle vs low = 4.945). The positive expression rate of cyclin A was significantly higher in high (100%, 14/14) and middle GAS groups (82.6%, 19/23) than in low GAS group (54.8%, 23/42) (P<0.01, x2high vs low = 9.586; P<0.05,x2middle vs low = 5.040). The positive expression rate of CDK2 was significantly higher in high (92.9%, 13/14) and middle GAS groups (87.0%, 20/23) than in low GAS group (50.0%, 21/42) (P<0.01,x2high vs low=8.086; P<0.01,x2middle vs low = 8.715). The positive expression rate of CDK4 was significantly higher in high (78.6%, 11/14) and middle GAS groups (78.3%, 18/23) than in low GAS group (42.9%, 18/42) (P<0.05, x2high vs low= 5.364; P<0.01, x2middle vs low = 7.539). The positive expression rate of cyclin E was prominently higher in low SS group (53.3%, 24/45) than in high (9.1%, 1/11) and middle (21.7%, 5/23) SS groups (P<0.05, x2high vs low= 5.325; P<0.05, x2middle vs low = 6.212). The positive expression rate of CDK2 was significantly higher in low SS group (77.8%, 35/45) than in high SS group (27.3%, 3/11) (P<0.01,x2high vs low = 8.151). There was a significant positive correlation between the integral ratio of GAS to SS and the semi-quantitative integral of cyclin D1, cyclin E, cyclin A, CDK2, CDK4 (P<0.05, D1rs = 0.252; P<0.01, Ers = 0.387; P<0.01, Ars = 0.466; P<0.01, K2rs = 0.519; P<0.01,K4rs= 0.434). CONCLUSION: The regulation and control of gastrin, SS in colorectal cancer cell growth may be directly related to the abnormal expressions of cyclins Dl, A, E, and CDK2, CDK4. The regulatory site of GAS in the cell cycle of colorectal carcinoma may be at the G1, S and G2 phases. The regulatory site of SS may be at the entrance of S phase.     

Deregulation of G1/S transition is a common event in carcinoma of the ampulla of vater

BACKGROUND/AIMS: Aberrant expression of cell cycle regulators and subsequent deregulation of G1/S transition is one of the most important characteristics of human cancer. The aim of this study was to determine the overall pattern of deranged expression of the cell cycle regulators involved in the G1/S transition in ampullary carcinoma. METHODOLOGY: Using immunohistochemistry, we investigated the expression of p21WAF1/CIP1, p27Kip1, p16INK4, cyclin D1, cyclin E, pRb and p53 in 14 resected specimens of ampullary carcinoma and defined the proliferative activity of each tumor by quantifying Ki-67 antigen. RESULTS: Decreased expression of p21WAF1/CIP1, p27Kip1, and p16INK4 was detected in 6 (43%), 11 (79%), and 4 (29%) tumors, respectively. Four tumors (29%) overexpressed cyclin D1 and 8 (57%) overexpressed cyclin E. Eight tumors (57%) overexpressed pRb. Aberrant accumulation of p53 was observed in 10 (71%) of the tumors. Overall, the expression of two or more of these cell cycle regulators was altered in all of the 14 tumors. Decreased p21WAF1/CIP1 expression was related to higher TMN stage (P = 0.04) and lymphatic invasion (P = 0.04). The proliferative index was higher in tumors with decreased p27Kip expression (P = 0.005), and in tumors with cyclin E overexpression (P = 0.06). CONCLUSIONS: Our observations suggest that deregulation of G1/S transition is a very common event in ampullary carcinoma, and that altered expression of cell cycle regulators is associated with the aggressive behavior of this tumor. Correcting the G1/S transition regulatory machinery may provide a novel therapy for this malignancy.     

Expression of thymidylate synthase in human gastric and colorectal adenocarcinomas is upregulated by p16/INK4

BACKGROUND/AIMS: We observed the relationship between the expression of thymidylate synthase protein (pTS) and cell cycle regulators in gastric and colorectal adenocarcinoma tissues. METHODOLOGY: This study included 80 gastric and 50 colorectal adenocarcinomas. Immunohistochemical staining was performed using a polyclonal antibody to recombinant human pTS, and monoclonal antibodies to p53, p21/WAF1CIP1, p16/INK4, cyclin D1 and pRB. Each staining was quantified using computerized image analysis on a CAS 200 system. We selected the mean expression values as the cutoff values to distinguish between high and low expression of these substances. RESULTS: There was no relationship between pTS expression and p21/WAF1CIP1, cyclin D1, or pRB expression in gastric and colorectal carcinomas. In both gastric and colorectal carcinomas, the pTS expression was significantly low in the high p16/INK4 expression subgroup compared with the low p16/INK4 expression subgroup (P < 0.05). Further, the pTS expression was significantly high in the high p53 expression subgroup compared with the low p53 expression subgroup in colorectal adenocarcinomas (P < 0.05). CONCLUSIONS: pTS expression regulation in human gastric and colorectal adenocarcinomas in complex, and upregulated by p16/INK4.     

Aberrant expression of G1-phase cell cycle regulators in flat and exophytic adenomas of the human colon

BACKGROUND & AIMS: The G1/S-phase controlling mechanism known as the RB pathway is commonly deregulated in human malignancies. Here, the abundance and localization of key components of the retinoblastoma (RB) pathway were determined in exophytic and flat colorectal adenomas. METHODS: Samples of normal colonic mucosa (n = 41) and flat (n = 45) and exophytic (n = 26) adenomas were examined immunohistochemically using antibodies to cyclins D1, D2, D3, cyclin-dependent kinase (CDK) 4, retinoblastoma protein (pRB), and the CDK inhibitors p16INK4a, p18INK4c, and p19INK4d. RESULTS: In normal colonic epithelium, cyclin D2 was undetectable; expression of cyclin D1, CDK4, and pRB correlated with proliferation; and p16, p18, p19, and cyclin D3 were most abundant in quiescent, differentiated cells. Adenomas showed elevated expression of cyclin D1 and pRB, frequent induction of cyclin D2, and absence of p16. No obvious abnormalities were found for p18, p19, or cyclin D3. Overexpressed cyclin D2 was more common among exophytic and pRB among flat adenomas, respectively. Elevated cyclin D1, D2, and CDK4 correlated with enhanced dysplasia. CONCLUSIONS: Aberrant expression of cyclins D1, D2, CDK4, p16, and pRB occur in significant subsets of exophytic and flat adenomas, particularly among cases with high-grade dysplasia. Such defects of the RB pathway may perturb cell-cycle control and thereby contribute an early step in colorectal tumorigenesis.     

Expression of cell-cycle regulatory proteins in endometrial carcinomas: correlations with hormone receptor status and clinicopathologic parameters

PURPOSE: The normal human endometrium is characterized by hormone-dependent variations in the levels of cell-cycle regulatory proteins during the menstrual cycle. As this tightly controlled system is disturbed in endometrial carcinomas, we analyzed which cell-cycle regulators are involved in endometrial carcinogenesis. METHODS: We performed Western blot analysis of five cell-cycle stimulating (cyclins D1, E, B1, cdk2, cdk4) and three cell-cycle inhibiting (p16(INK4a), p21(WAF1), Rb) proteins in 41 endometrial carcinoma specimens. In addition, expression of the estrogen and progesterone receptors (ER, PR), Ki67, and, in selected cases, p16, cyclin E, and cyclin B1 was studied by immunohistochemistry. RESULTS: We found upregulation of all analyzed cell-cycle regulators in most tumors compared to normal endometrial tissue samples. Overexpression of cyclin E, cyclin B1, and p21 was associated with a less differentiated phenotype. In addition, high levels of cyclin E, cdk2, and cdk4 correlated with weak/absent ER expression, and p16 and p21 overexpression was significantly associated with low PR immunoreactivity. Cyclin B1 expression correlated with cyclin E, cdk2, cdk4, p21, Rb, and Ki67, and cyclin E expression with cyclin D1 and Rb. CONCLUSIONS: We conclude that cyclin E and cyclin B1 might be the major cell-cycle regulators involved in proliferation and reduced differentiation of endometrial carcinomas. In addition, p16, p21, and Rb appear to be uncoupled from their normal cell-cycle inhibiting function in many endometrial carcinomas.     

大鼠肾小球系膜细胞表型的增龄性变化

目的 观察大鼠肾小球系膜细胞随增龄细胞表型及功能的变化特点. 方法取3、12、24月龄健康雄性Wistar大鼠原代系膜细胞进行培养,MTT法检测细胞增殖能力,进行SA-β-gal染色,采用RT-PCR和Western印迹法分别检测p21~(WAF1/CIP1/SDI1)基因及蛋白质的表达变化,并用免疫荧光法检测系膜细胞中p21~(WAF1/CIP1/SDI1)的表达与定位. 结果大鼠肾小球系膜细胞增殖能力随增龄逐渐减弱(P<0.05),SA-β-gal染色阳性率随增龄逐渐增加(P<0.05),p21~(WAF1/CIP1/SDI1) mRNA及蛋白质表达随增龄逐渐增加(P<0.05).免疫荧光结果示p21~(WAF1/CIP1/SDI1)主要在细胞核内表达,荧光强度随增龄逐渐增强 (P<0.05). 结论大鼠肾小球系膜细胞随增龄细胞形态、增殖能力与衰老相关蛋白表达发生明显改变,出现了复制性衰老表型.     

Correlation between expression of gastrin, somatostatin and cell apoptosis regulation gene bcl-2／bax in large intestine carcinoma

AIM: To explore the correlation between expression of somatostatin (SS), gastrin (GAS) and cell apoptosis regulation gene bcl-2/bax in large intestine carcinoma. METHODS: Sixty-two large intestine cancer tissue samples were randomly and retrospectively selected from patients with large intestine carcinoma. Immunohistochemical staining for bcl-2, bax, GAS, SS was performed according to the standard streptavidin-biotin-peroxidase (S-P) method. According to the semi-quantitative integral evaluation, SS and GAS were divided into three groups as follows. Scores 1-3 were defined as the low expression group, 4-8 as the intermediate expression group, 9-16 as the high expression group. Bax and bcl-2 protein expressions in different GAS and SS expression groups of large intestine carcinoma were assessed. RESULTS: The positive expression rate of bax had a prominent difference between SS and GAS high, intermediate and low expression groups (P<0.05, x2SS = 9.246; P<0.05, x2GAs = 6.981). The positive expression rate of bax in SS high (80.0%, 8/10) and intermediate (76.5%, 13/17) expression groups was higher than that in low expression group (40.0%, 14/35) (P<0.05, X2high vslow = 5.242; P<0.05, x2middle vs low = 6.097). The positive expression rate of bax in GAS high expression group (27.3%, 3/8) was lower than that in low expression group (69.4%, 25/36) (P<0.05, x2 = 4.594). However, bax expression in GAS intermediate expression group (46.7%, 7/15) was lower than that in low expression group, but not statistically significant. The positive expression rate of bcl-2 had a prominent difference between SS and GAS high, intermediate and low expression groups (P<0.05, x2ss = 7.178; P<0.05, x2GAS = 13.831). The positive expression rate of bcl-2 in GAS high (90.9%, 10/11) and intermediate (86.7%, 13/15) expression groups was higher than that in low expression group (44.4%, 16/36) (P<0.05, x2high,vslow = 5.600; P<0.05, x2middle vs low = 7.695). However, the positive expression rate of bcl-2 in SS high (40. 0%, 4/10) and intermediate (47.1%, 8/9) expression groups was lower than that in low expression group (77.1%, 27/35) (P<0.05, x2high vs low = 4.710; P<0.05, x2middle vs low = 4.706). There was a significant positive correlation between the integral ratio of GAS to SS and the integral of bcl-2 (P<0.01, r = 0.340). However, there was a negative correlation between the integral ratio of GAS to the SS and bax the integral of (P<0.05, r= -0.299). CONCLUSION: The regulation and control of gastrin, somatostatin in cell apoptosis of large intestine carcinoma may be directly related to the abnormal expression of bcl-2, bax.     

Cell cycle deregulation in liver lesions of rats with and without genetic predisposition to hepatocarcinogenesis

Preneoplastic and neoplastic hepatocytes undergo c-Myc up-regulation and overgrowth in rats genetically susceptible to hepatocarcinogenesis, but not in resistant rats. Because c-Myc regulates the pRb-E2F pathway, we evaluated cell cycle gene expression in neoplastic nodules and hepatocellular carcinomas (HCCs), induced by initiation/selection (IS) protocols 40 and 70 weeks after diethylnitrosamine treatment, in susceptible Fisher 344 (F344) rats, and resistant Wistar and Brown Norway (BN) rats. No interstrain differences in gene expression occurred in normal liver. Overexpression of c-myc, Cyclins D1, E, and A, and E2F1 genes, at messenger RNA (mRNA) and protein levels, rise in Cyclin D1-CDK4, Cyclin E-CDK2, and E2F1-DP1 complexes, and pRb hyperphosphorylation occurred in nodules and HCCs of F344 rats. Expression of Cdk4, Cdk2, p16(INK4A), and p27(KIP1) did not change. In nodules and/or HCCs of Wistar and BN rats, low or no increases in c-myc, Cyclins D1, E, and A, and E2F1 expression, and Cyclin-CDKs complex formation were associated with p16(INK4A) overexpression and pRb hypophosphorylation. In conclusion, these results suggest deregulation of G1 and S phases in liver lesions of susceptible rats and block of G1-S transition in lesions of resistant strains, which explains their low progression capacity.