二甲双胍对人胰腺癌细胞增殖与凋亡的影响

背景与目的:近年研究发现二甲双胍对多种肿瘤具有抑制作用,部分临床研究也发现二甲双胍可以降低糖尿病并发胰腺癌的风险和降低胰腺癌的死亡危险。本研究从细胞水平着手研究二甲双胍对胰腺癌细胞增殖和凋亡的影响,并初步探讨其可能机制。方法:体外培养人胰腺癌细胞株Bxpc-3,予二甲双胍进行干预作为二甲双胍干预组,无药物组作为对照组。以MTT检测二甲双胍对Bxpc-3细胞存活率的影响,流式细胞术检测二甲双胍对Bxpc-3细胞周期的影响,流式细胞术及Hoechst 33258荧光染色法检测细胞凋亡,RT-PCR检测AMPKα1、Bax、Bcl-2、Caspase-3、Cyclin D1 mRNA的表达。蛋白质印迹法(Western blot)检测Cyclin D1、Bax、Bcl-2、Caspase-3蛋白的表达。结果:与对照组相比,MTT检测结果显示,二甲双胍可以抑制人胰腺癌细胞株Bxpc-3的增殖,并呈时间-浓度依赖性(F=8.99、124和114.61,P<0.01);流式细胞术检测结果显示,二甲双胍干预组与对照组相比,G0/G1期细胞所占百分比增加(t=-8.71,P<0.01),S期(t=7.54,P<0.01)及G2/M期(t=7.00,P<0.01)细胞所占百分比减少;流式细胞术(早期凋亡率t=-2.68,晚期凋亡率t=1.29,总凋亡率t=-0.85)及Hoechst 33258荧光染色法(t=-0.46)结果显示,两组细胞凋亡率差异无统计学意义(P>0.05);RT-PCR结果显示,二甲双胍干预组Cyclin D1 mRNA表达明显降低(t=4.96,P<0.01),AMPKα1、Bax、Bcl-2、Caspase-3 mRNA表达与对照组相比,差异无统计学意义(t=1.68、-0.56、-1.80、0.67,P>0.05);Westernblot结果显示,二甲双胍干预组Cyclin D1蛋白表达明显降低(t=7.02,P<0.01),Bax、Bcl-2、Caspase-3蛋白表达与对照组相比,差异无统计学意义(t=-0.11、-0.20,0.11,P>0.05)。结论:二甲双胍能显著抑制人胰腺癌细胞株Bxpc-3的增殖,机制主要与其阻滞细胞周期、下调Cyclin D1表达有关;二甲双胍对Bxpc-3细胞的凋亡无明显诱导作用。     

二甲双胍对肺癌A549细胞增殖、迁移、侵袭能力及乳酸生成的影响

摘 要：［目的］ 探讨二甲双胍对肺癌A549细胞增殖、迁移、侵袭能力、乳酸生成的影响。［方法］ 应用AnnexinV/PI和API等标记,流式细胞仪对肺癌A549细胞凋亡及周期特异性的检测,运用RT-PCR的方法检测Caspase-3、Caspase-9活化情况。MTT检测细胞增殖活力;Transwell体外迁移实验检测细胞体外迁移和侵袭能力;并检测乳酸生成情况。［结果］ 二甲双胍诱导的细胞凋亡主要在细胞周期的G1期发生。采用二甲双胍凋亡诱导,对照组未做处理,结果显示观察组的Caspase-3 mRNA（1.12±0.56）、Caspase-9 mRNA（1.10±0.29）的表达值显著高于对照组（0.82±0.31,0.72±0.26）。Transwell结果显示,第7d二甲双胍组体外迁移细胞数（2.69±0.56）明显增加;二甲双胍组细胞活力（52.39%±5.96%）下降;二甲双胍组乳酸生成（12.89±1.03）明显降低。［结论］ 二甲双胍诱导的细胞凋亡与肺癌A549细胞的细胞周期相关,存在G1期细胞周期阻滞的周期特异性,且此过程中发生了caspase活化,抑制细胞活性及迁移侵袭能力,降低乳酸的生成,促进肿瘤细胞凋亡。     

二甲双胍对胰腺癌和胰腺癌干细胞中ALDH1表达的作用北大核心CSCD

目的观察二甲双胍对胰腺癌PANC-1细胞和胰腺癌干细胞中ALDH1表达的影响,探讨其作用机制。方法采用CCK-8和Western blot检测不同浓度二甲双胍对胰腺癌PANC-1细胞的增殖及ALDH1和p-mTOR蛋白表达的影响。Western blot、免疫荧光法及q RT-PCR检测二甲双胍、雷帕霉素以及联合用药组PANC-1细胞中ALDH1、4EBP1、p-m TOR蛋白及m RNA的表达。超低黏附培养板悬浮培养胰腺癌细胞后观察干细胞成球数目的改变以及Western blot检测干细胞ALDH1的表达;建立胰腺癌裸鼠移植瘤模型比较PANC-1细胞以及胰腺癌成球细胞的成瘤能力。结果二甲双胍抑制胰腺癌PANC-1细胞的增殖,且呈时间剂量依赖性,最佳干预时间为48 h,IC50约为20 mmol/L;与对照组相比,二甲双胍、雷帕霉素和联合用药组ALDH1、4EBP1、p-mTOR的ALDH1的蛋白表达以及m RNA水平明显降低(P<0.05)。胰腺癌成球细胞的体外成瘤能力以及ALDH1的表达比PANC-1细胞组显著增高;相比于对照组,二甲双胍、雷帕霉素和联合用药组胰腺癌细胞的成球能力以及胰腺癌干细胞中ALDH1的表达均显著降低(P<0.05)。结论二甲双胍以及雷帕霉素均能显著抑制胰腺癌PANC-1细胞和胰腺癌干细胞ALDH1的表达,其作用机制可能是通过抑制mTOR通路。     

二甲双胍抑制胰腺癌干细胞生长的实验研究

摘 要：［目的］ 探讨二甲双胍对胰腺癌干细胞的生长抑制作用。［方法］ 利用无血清培养基的超低粘附培养方法获得干细胞球样胰腺癌PANC1细胞,然后通过定量PCR检测干细胞球样PANC1细胞中CD133及PDX-1的表达情况,验证胰腺癌干细胞;利用干细胞球样PANC1细胞的MTT实验、流式周期检测实验、Annexin-Ⅴ细胞凋亡实验、定量PCR凋亡因子检测实验,研究二甲双胍对干细胞球样PANC1细胞增殖、周期及凋亡的影响;借助干细胞球样PANC1胰腺癌细胞构建鼠移植瘤模型,观察二甲双胍对肿瘤生长的影响。［结果］ 二甲双胍能够明显抑制干细胞球样胰腺癌PANC1细胞增殖,且具有浓度依赖性,最大抑制率为81.3%,半数有效抑制浓度IC50为（11.94±1.43）mmol/L;二甲双胍对干细胞球样PANC1细胞的G0/G1期有阻滞作用;二甲双胍可以诱导干细胞球样PANC1细胞凋亡,与空白对照组比较,二甲双胍组干细胞球样PANC1细胞的Bcl-2 mRNA减少,而Bad、Bax mRNA的表达增加;干细胞球样PANC1细胞接种至裸鼠皮下均能成瘤,且二甲双胍能够明显抑制移植瘤的生长。［结论］ 二甲双胍能够抑制胰腺癌干细胞增殖,阻滞G0/G1期,并诱导胰腺癌干细胞凋亡,发挥抗胰腺癌干细胞生长的作用。     

miR-762在胰腺癌中的表达及对胰腺癌细胞生物学行为的影响

背景与目的：miR-762在多种恶性肿瘤中存在表达异常,参与肿瘤的增殖、凋亡及侵袭转移。观察miR-762在胰腺癌组织和细胞系中的表达及对胰腺癌细胞增殖、侵袭转移的影响。方法：采用实时荧光定量聚合酶链反应（real-time fluorescence quantitative polymerase chain reaction,RTFQ-PCR）技术检测于河北医科大学第四医院行胰腺癌根治术的胰腺癌组织和细胞株中miR-762的表达。通过Lipofectamine ^TM 2000将miR-762模拟物（mimics）、miR-762抑制物（inhibitors）及其阴性对照序列（scramble序列）分别转染胰腺癌PANC-1细胞。采用细胞计数试剂盒（cell counting kit-8,CCK-8）实验检测细胞增殖;采用流式细胞术检测细胞凋亡;采用划痕实验和Transwell侵袭实验检测细胞侵袭转移能力;采用蛋白质印迹法（Western blot）检测上皮-间质转化（epithelial-mesenchymal transformation,EMT）相关分子标志物表达。结果：胰腺癌组织中miR-762 mRNA表达量显著高于癌旁组织（P<0.01）。胰腺癌细胞株BxPC-3、PANC-1、AsPC-1、SW-1990中miR-762 mRNA的表达量也显著高于正常胰腺上皮细胞HPDE（P<0.01）。转染miR-762 mimics后PANC-1细胞miR-762 mRNA表达量显著增加,而转染miR-762 inhibitors后PANC-1细胞miR-762 mRNA表达量显著降低（P<0.01）。同时miR-762 mimics组450 nm处的吸光度（D ₄₅₀ ）值、细胞迁移距离和穿膜细胞数及间质表型细胞标志物N-钙黏蛋白（N-cadherin）、波形蛋白（vimentin）表达量显著增加,细胞凋亡率及上皮细胞标志物E-钙黏蛋白（E-cadherin）表达量显著降低;而miR-762inhibitors组D ₄₅₀ 、细胞迁移距离和穿膜细胞数及间质表型细胞标志物N-cadherin、vimentin表达量显著降低,细胞凋亡率及上皮细胞标志物E-cadherin表达量显著增加（P<0.05）。结论：miR-762在胰腺癌组织和细胞株中高表达,上调miR-762表达可能通过调控N-cadherin、vimentin、E-cadherin表达促进EMT进程,从而增强PANC-1细胞的增殖和侵袭转移能力。     

survivin 反义核酸增强PANC-1 细胞对5-Fu敏感性的研究

 目的 研究survivin反义核酸诱导胰腺癌细胞株PANC-1的凋亡和增强对5-Fu敏感性的影响。方法 我们应用构建的survivin反义核酸真核表达栽体电转染PAND-1细胞，RT-PCR检测survivin mRNA表达，细胞计数和MTT实验测定转染后细胞对5-Fu敏感性，流式细胞仪检测细胞凋亡。结果 survivin反叉核酸可抑制PANC-1细胞中survivin mRNA的表达，并能抑制PANC-1细胞生长，提高PANC-1对5-Fu敏感性，流式细胞仪检测凋亡率明显增加。结论 survivin反义核酸能增强5-Fu诱导的PANC-1细胞凋亡，联合survivin反义核酸和5-Fu可以改善胰腺癌的治疗效果。     

靶向EGFR基因的shRNA抑制胰腺癌PANC-1细胞增殖的研究

目的探讨EGFR基因对胰腺癌PANC-1细胞的增殖抑制作用。方法构建针对EGFR序列特异性shRNA的表达载体,用脂质体转染胰腺癌PANC-1细胞。采用RT-PCR、Western blot检测EGFR mRNA和蛋白的表达;流式细胞仪检测细胞周期及凋亡;克隆形成实验检测细胞增殖。结果靶向EGFR的序列特异性shRNA明显抑制EGFR mRNA和蛋白的表达,EGFR mRNA和蛋白的抑制率分别为72.1％和67.6％;G1期细胞增多、S期细胞减少(P<0.05);细胞凋亡增加(P<0.05);克隆形成减少(P<0.05)。结论靶向EGFR的序列特异性shRNA能明显抑制胰腺癌细胞增殖、促进凋亡。     

5-氮杂-2-脱氧胞苷对人胰腺癌细胞株PANC-1侵袭和迁移能力的影响

目的   研究甲基化抑制物5-氮杂-2-脱氧胞苷(5-Aza-CdR)干预对胰腺癌细胞株PANC-1侵袭和迁移能力的影响,初步探讨其发挥作用的机制。方法   用不同浓度的5-Aza-CdR处理PANC-1细胞株,采用划痕迁移试验和Transwell小室法观察干预前后细胞迁移和侵袭能力的改变,免疫荧光染色法检测干预前后细胞MMP-2的表达。结果   经5-Aza-CdR干预后,与对照组相比,PANC-1细胞的迁移和侵袭能力明显减弱（P<0.05）,细胞内MMP-2的表达降低(P<0.05)。结论   5-Aza-CdR可以明显抑制胰腺癌细胞株PANC-1的侵袭转移能力,其机制可能是通过抑制MMP-2的表达而降低肿瘤细胞的侵袭和转移。     

康莱特注射液对人胰腺癌细胞株PANC-1增殖和凋亡影响的实验研究

目的：通过康莱特注射液作用于人胰腺癌细胞株 PANC-1,观察其对 PANC-1细胞增殖和凋亡的影响,并进一步探讨其作用机制。方法倒置显微镜及电镜观察80μL·mL -1康莱特注射液作用 PANC-1细胞72 h 后细胞形态改变;采用 MTT 比色法检测不同浓度（10、20、40、60、80、100μL·mL -1）康莱特注射液对PANC-1细胞生长增殖抑制作用的影响;同时采用流式细胞术检测不同浓度（10、20、40、60、80、100μL·mL -1）康莱特注射液对 PANC-1细胞周期的影响。结果细胞形态学检查发现80μL·mL -1康莱特注射液处理 PANC-1细胞72 h 后细胞生长稀疏,细胞质透亮度下降,线粒体等细胞器功能障碍,细胞核功能上受到一定的抑制;不同浓度康莱特注射液作用于 PANC-1细胞株不同时段（24、48、72 h）后肿瘤细胞生长受到了一定的抑制且呈现时间和剂量依赖性;不同浓度康莱特注射液处理 PANC-1胰腺癌细胞72 h 后 PANC-1细胞周期均阻滞于 G2/ M 期,康莱特注射液可剂量依赖性的诱导 PANC-1细胞凋亡。结论康莱特注射液能够有效抑制人胰腺癌细胞株 PANC-1在体外的生长,其机制可能是通过抑制细胞增殖,促进肿瘤细胞的凋亡而实现,有望成为胰腺癌的有效治疗药物。     

Cytologic classification of precancer and cancer of the endometrium and esophagus and of malignant lymphomas

The paper discusses cytological classifications of precancer and cancer of the endometrium, esophagus and malignant lymphomas presented by cytologists from five Soviet research institutes of oncology. The classifications were based on the data of 4400 cases in conformity with WHO histologic classifications.     

E-钙粘蛋白及PTEN基因编码蛋白与胃癌浸润转移

目的:观察抑癌基因PTEN蛋白和ECD在胃癌组织中的表达,探讨其与胃癌生物学行为及预后的关系。方法:以兔抗人PTEN多克隆抗体、鼠抗人ECD单克隆抗体,采用SABC免疫组化法,检测100例胃癌手术切除标本中拟测指标的表达。以χ2和Logrank检验对结果做统计学分析。结果:ECD、PTEN蛋白在非癌胃粘膜中均见表达;在胃癌组织中表达下调或缺失。ECD异常表达率为42.0%;弥漫型胃癌异常表达率(48.57%),明显高于肠型胃癌(26.67%),(P<0.05);ECD异常表达与浸润深度有关(P<0.05)。胃癌组织中PTEN蛋白缺失率为59%;弥漫型胃癌缺失率(65.71%)明显高于肠型胃癌(43.33%),(P<0.05);伴淋巴结转移的胃癌缺失率(64.47%)明显高于无淋巴结转移者(41.67%),(P<0.05);PTEN蛋白缺失的患者比阳性表达者预后差(P=0.0066)。65.85%PTEN阳性表达者同时伴ECD正常表达。结论:两种标志物与胃癌浸润转移有关,PTEN表达与胃癌患者预后密切相关。将两种指标联合检测,可作为正确判断胃癌患者预后,指导临床治疗的分子生物学指标。     

Schwannomas of Head and Neck and Review of Literature

Benign nerve cell tumours have been given various names like schwannoma, neurilemmoma, neurinoma, neurofibroma, spindle cell tumours etc. Extra cranial head and neck schwannomas usually present as solitary and well-demarcated lesions. The lesion can cause secondary symptoms, such as nasal obstruction, dysphasia, and hoarseness, depending upon the location of the lesion. Fine needle aspiration cytology, CT scans, and MRI may be of limited help in the diagnosis of schwannomas. The treatment is complete surgical excision of the benign tumour and postoperative histopathological examination establishes the final diagnosis.     

世界卫生组织骨质疏松症防治工作报告和防治建议

引 言 作为对第51号综合处理非传染性疾病预防与控制的世界卫生组织决议的反应,1998年7月WHO成立了致力于不断完善对骨质疏松预防和治疗策略的工作小组。小组成员来自世界各国致力于骨质疏松研究的知名专家。Harry K.Genant为本届主席。这一项世界范围内的骨质疏松教育计划旨在通过世界范围的研究,不断改善对骨质疏松的诊断水平和发展并完善对骨质疏松病人的合理治疗。其重点将以发展中国家为主。并为各国政府及其卫生部门和病人群体提供世界性有关骨质疏松症的总体的、完整的指导性资料。该项研究、教育计划的实施将由世界各国的骨质疏松症研究和治疗机构共同完成,并经权威学术机构、政府和非政府组织进行有针对性的回顾研究,最终由WHO审议通过。     

Prospective study of fruit and vegetable consumption and incidence of colon and rectal cancers

BACKGROUND: Frequent consumption of fruit and vegetables has been associated with a reduced risk of colorectal cancer in many observational studies. METHODS: We prospectively investigated the association between fruit and vegetable consumption and the incidence of colon and rectal cancers in two large cohorts: the Nurses' Health Study (88 764 women) and the Health Professionals' Follow-up Study (47 325 men). Diet was assessed and cumulatively updated in 1980, 1984, 1986, and 1990 among women and in 1986 and 1990 among men. The incidence of cancer of the colon and rectum was ascertained up to June or January of 1996, respectively. Relative risk (RR) estimates were calculated with the use of pooled logistic regression models accounting for various potential confounders. All statistical tests were two-sided. RESULTS: With a follow-up including 1 743 645 person-years and 937 cases of colon cancer, we found little association of colon cancer incidence with fruit and vegetable consumption. For women and men combined, a difference in fruit and vegetable consumption of one additional serving per day was associated with a covariate-adjusted RR of 1.02 (95% confidence interval [CI] = 0.98-1.05). A difference in vegetable consumption of one additional serving per day was associated with an RR of 1.03 (95% CI = 0.97-1.09). Similar results were obtained for women and men considered separately. A difference in fruit consumption of one additional serving per day was associated with a covariate-adjusted RR for colon cancer of 0.96 (95% CI = 0.89-1.03) among women and 1. 08 (95% CI = 1.00-1.16) among men. For rectal cancer (total, 244 cases), a difference in fruit and vegetable consumption of one additional serving per day was associated with an RR of 1.02 (95% CI = 0.95-1.09) in men and women combined. None of these associations was modified by vitamin supplement use or smoking habits. CONCLUSIONS: Although fruits and vegetables may confer protection against some chronic diseases, their frequent consumption does not appear to confer protection from colon or rectal cancer.     

A comparative study of knowledge and awareness of colorectal and breast cancerA comparative study of knowledge and awareness of colorectal and breast cancer

Aims: To assess and compare knowledge and awareness of colorectal cancer and breast cancer in a sample of the general population. Methods: Eleven hundred visitors to six different outpatient clinics, in a University Hospital, were given a study-specific questionnaire, based on educational material from the British Association of Cancer United Patients (CancerBACUP). The questionnaire consisted of 12 statements on the incidence, presentation, detection, treatment and prognosis of colorectal and breast cancer. Results: One thousand and sixty-eight individuals returned the questionnaire. One thousand and four completed questionnaires were analysed. The mean age (SD) of respondents was 50.1 (17.2) years, and the male to female ratio was 2:3. Respondents had read more about breast than about colorectal cancer (60.3%vs 32.4%,P <0.0001, McNemar's test). The proportion of correct answers for each statement on breast cancer was higher than for answers to corresponding items on colorectal cancer. Mean overall scores (95% CI) for breast and colorectal cancer were 88.1 (86.9, 89.2) and 64.4 (62.5, 66.3) respectively, the mean difference (95% CI) being 23.7 (22.0, 25.5). Scores were higher for breast cancer irrespective of age or gender. Conclusion: There is a low level of understanding of colorectal cancer in the general population when compared to breast cancer. This highlights the importance of public education in this common cancer.     

Quality of life and care in leukemia,myeloma and non-malignant disease. Opinions of patients and relatives,and effects of geography and time

In a questionnaire study 140 subjects answered 4200 questions in 1980 and 1986. They consisted of patients with myeloma, acute leukemia, lung carcinoma, and non-malignant disease and their relatives. In 22 additional cases the questionnaire was not answered. The results show that myeloma patients are less content with the general care than leukemia patients (P < 0.05). Similarly, relatives of deceased myeloma patients are less satisfied with the information given to them than relatives of deceased leukemia patients (P < 0.001). The information has improved with time, however, since the patients were more satisfied in 1986 than in 1980 (P < 0.001) and relatives of myeloma patients still alive were more satisfied than relatives of patients who had died earlier (P < 0.001).     

Quality of life and care in leukemia, myeloma and non-malignant disease. Opinions of patients and relatives, and effects of geography and time

In a questionnaire study 140 subjects answered 4200 questions in 1980 and 1986. They consisted of patients with myeloma, acute leukemia, lung carcinoma, and non-malignant disease and their relatives. In 22 additional cases the questionnaire was not answered. The results show that myeloma patients are less content with the general care than leukemia patients (P less than 0.05). Similarly, relatives of decreased myeloma patients are less satisfied with the information given to them than relatives of deceased leukemia patients (P less than 0.001). The information has improved with time, however, since the patients were more satisfied in 1986 than in 1980 (P less than 0.001) and relatives of myeloma patients still alive were more satisfied than relatives of patients who had died earlier (P less than 0.001). The opinions of patients were similar to those of their relatives. However, the relatives of leukemia patients were even more satisfied with the contact with the medical staff than the patients themselves (P less than 0.05). As many as 10-30% of the relatives never gave up hope for their relative's survival. Only two out of 27 deaths were considered not dignified. The lung carcinoma patients reported a less good quality of life (P less than 0.001), and less satisfaction with the information given (P less than 0.01), than the hematological patients from the same year. Similarly, their attitude to the medical care improved less (P less than 0.01), and they were less content with the general care than the leukemia group (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)