HuR基因克隆及其在肝癌细胞中的表达

目的:克隆人抗原R基因（HuR）的cDNA,构建重组真核表达载体pEGFP-HuR,并稳定转染肝癌细胞株。方法:应用逆转录聚合酶链反应技术,从肝癌细胞中扩增得到人HuR基因的cDNA序列,克隆至增强型绿色荧光蛋白表达载体中,经Xho I和EcoR I双酶切和DNA测序鉴定后,将重组真核表达载体通过脂质体法导入肝癌细胞中,利用新霉素(G418)筛选出稳定转染pEGFP-HuR的肝癌细胞株,并用Western blot技术检测HuR基因的表达。结果:Xho I和EcoR I双酶切和PCR结果证实真核表达载体pEGFP-HuR构建成功。Western blot结果显示,在稳定转染重组真核表达载体的肝癌细胞中HuR基因表达水平上调。结论:成功构建了真核表达载体pEGFP-HuR,并筛选获得其稳定转染后HuR表达上调的肝癌细胞株,作为进一步研究HuR基因生物学功能的前期工作。     

5-Aza-CdR诱导肿瘤细胞NY-ESO-1抗原的表达

目的：探讨甲基化抑制剂5-氮杂-2′-脱氧胞苷（5-Aza-2′-deoxycytidine, 5-Aza-CdR）对肿瘤细胞中NY-ESO-1抗原表达的诱导作用。方法：常规培养人胃癌细胞株SGC-7901、人肝癌细胞株H2P和MHCC97-H、人结肠癌细胞株HT-29和LoVo及人脑胶质瘤细胞株U251,RT-PCR和免疫细胞化学法检测5-Aza-CdR作用前后肿瘤细胞中NY-ESO-1 mRNA和蛋白的表达。结果：RT-PCR与免疫细胞化学检测仅见胃癌SGC-7901细胞阳性表达NY-ESO-1,其余5株肿瘤细胞不表达NY-ESO-1。NY-ESO-1阴性的肝癌细胞株H2P、结肠癌细胞株LoVo及脑胶质瘤细胞株U251经5-Aza-CdR（终浓度分别为1、5和10 μmol/L）处理6 d后,细胞形态和生长速度均无明显改变,而NY-ESO-1 mRNA和蛋白均被诱导为阳性表达,并随5-Aza-CdR浓度增加而阳性表达逐渐增强。结论：5-Aza-CdR能诱导肝癌、结肠癌、脑胶质瘤等肿瘤细胞中NY-ESO-1抗原的表达,为肿瘤免疫治疗提供了一条新思路。     

Hedgehog信号通路对某些消化道肿瘤细胞生长的调节作用

目的：研究Hedgehog信号通路成员Shh、patched（PTCH）、smoothened（Smo）和Gli-1在结肠癌和胰腺癌细胞株以及人结肠腺瘤组织细胞中的表达情况,并探讨Smo受体特异性小分子抑制剂环靶明（cyclopamine）对这些肿瘤细胞生长的影响。方法：体外培养结肠癌细胞LS174T、HCT116、SW116、CT26和胰腺癌细胞BxPC3,并肠镜下摘取2例结肠腺瘤组织标本,提取细胞株和腺瘤组织总RNA,用RT-PCR扩增Shh,PTCH,Smo,Gli-1基因;使用MTT法检测环靶明在体外对这些肿瘤细胞生长的抑制作用。结果：在SW116、CT-26、BxPC3细胞和2例结肠腺瘤组织中Shh、PTCH、Smo和Gli-1均有不同程度的表达,而在HCT116和LS174T细胞中未能扩增出PTCH和（或）Smo基因的mRNA;环靶明对这些肿瘤细胞的生长有一定的抑制作用,且对Smo基因阳性表达细胞株的抑制作用更显著。结论：Hedgehog信号通路成员Shh、PTCH、Smo和Gli-1在结肠癌、胰腺癌及结肠腺瘤细胞中有不同程度的表达,环靶明对Smo高表达细胞的生长有明显抑制作用;提示该信号通路可能在部分消化道肿瘤细胞中被活化。     

转移抑制基因BRMS1mRNA在骨肉瘤细胞株中的表达及临床意义的研究

目的研究转移抑制基因BRMS1在人骨肉瘤细胞株中的体外转录水平,探讨其在侵袭转移过程中的作用。方法应用半定量RT-PCR技术检测BRMS1mRNA在3种人骨肉瘤细胞株(SaOS-2、HOS和MG-63)中的表达。结果半定量RT-PCR检测BRMS1mRNA在3株骨肉瘤细胞株中表达水平下降,在正常成骨细胞中则以较高水平表达。结论人骨肉瘤细胞株SaOS-2、HOS和MG-63细胞随侵袭转移能力的增强,BRMS1mRNA表达水平下降,为研究骨肉瘤的转移机制提供了理论基础。     

结肠癌转移相关基因1对结肠癌细胞肝转移的影响

目的:研究结肠癌转移相关基因1(metastasis-associated in colon cancer1,MACC1)的表达对结肠癌肝转移的影响。方法:将融合绿色荧光蛋白(green fluorescent proteins,GFP)的慢病毒表达载体分别感染具有不同转移潜能的人结肠癌细胞株SW1116和HCT116。给予BALB/c-nu/nu裸鼠脾脏注射感染后的结肠癌细胞,构建结肠癌肝转移模型。注射后35d,在荧光解剖显微镜下观察肝脏内结肠癌细胞的转移情况,计算肝转移率。应用蛋白质印迹法检测SW1116和HCT116细胞中MACC1蛋白的表达水平,评估MACC1的表达水平与肝转移率的关系。结果:SW1116细胞的肝转移率明显高于HCT116细胞。MACC1蛋白在HCT116细胞中呈低表达,而在SW1116细胞中呈高表达,差异有统计学意义(P<0.01)。结论:MACC1蛋白的表达水平可能与结肠癌的肝转移能力呈正相关。     

应用活体内生物发光技术对人高转移大细胞肺癌细胞株L9981成瘤性和转移性研究

背景与目的应用阳离子脂质体介导的基因转染方法对nm23-H1缺失的人高转移大细胞肺癌细胞株L9981进行荧光素酶基因(Luc)标记,建立稳定高效表达荧光素酶(Luciferase)基因的人高转移大细胞肺癌细胞株L9981-Luc。应用活体生物荧光成像技术,非侵入性地连续检测小鼠(裸鼠和SCID鼠)皮下肿瘤模型发展演进、自发转移的过程。方法将带有荧光素酶基因(Luc)的质粒PGL4.17经阳离子脂质体介导转入人高转移大细胞肺癌细胞株L9981中,筛选出高效稳定表达荧光素酶的细胞株。将转染后的细胞接种于裸鼠和SCID鼠右后腿腹股沟皮下,建立皮下肿瘤模型,利用活体内可见光成像系统观察其在小鼠体内的生长和转移过程。结果转基因人高转移大细胞肺癌细胞株L9981-Luc可在体内、外持续稳定表达荧光素酶,细胞数和发光值成直线相关。成功地建立了表达荧光素酶活性的动物肿瘤皮下自发转移模型。L9981-Luc保留了原有的高转移特性。瘤重和发光强度呈直线相关。结论利用活体内生物发光技术可以非侵袭性地连续示踪肿瘤细胞在活体内的生长和转移过程,为研究肺癌侵袭转移过程及其机理和最佳治疗策略的选择提供了新的手段和工具。     

CTHRC1基因在人肝癌中高表达并促进MHCC97L肝癌细胞的转移

目的：分析CTHRC1基因在人肝癌组织和肝癌细胞株中的表达情况及其对MHCC97L肝癌细胞转移能力的影响。方法：采用northem blot、RT—PCR和荧光定量PCR分析人肝癌组织和肝癌细胞株中CTHRC1 mRNA水平。构建包含CTHRC1基因编码框的真核表达载体pCMV-3Tag-CTHRC1，通过体外实验分析CTHRC1在MHCC97L细胞中过表达对MHCC97L细胞迁移、侵袭等转移能力的影响。结果：Northern blot、RT—PCR和荧光定量PCR结果显示，14例肝癌患者中11例存在癌组织CTHRC1 mRNA表达水平高于癌旁组织，8种肝癌细胞株中5种肝癌细胞株存在着CTHRC1的高表达。当CTHRC1过表达后，MHCC97L细胞的迁移及侵袭能力显著增强（P〈0．001）。结论：CTHRC1基因在人肝癌组织和人肝癌细胞株中存在着高表达，同时该基因可使肝癌细胞MHCC97L的转移能力明显增强，提示CTHRC1基因可能在肿瘤转移中起重要作用。     

结肠癌细胞转染IL-21基因抑瘤效应的实验研究

目的：初步探讨转染IL-21的结肠癌细胞抑制肿瘤生长的效应。方法：以逆转录病毒为载体将IL-21基因导入结肠癌细胞，筛选建立高表达细胞株，测定其生物学性状指标和抑制肿瘤生长的效果。结果：与原株相比，所建立的Colon26／IL-21细胞株可高质量的表达IL-21，在体内可刺激分泌大量的IFNγ，致使结肠肿瘤明显回缩、结论：IL-21是一种高效的抗肿瘤细胞因子，有望成为结肠癌基因治疗的的候选基因。     

5-杂氮-2'-脱氧胞苷对人结肠癌细胞E-cadherin基因表达及甲基化的影响

背景与目的:结肠癌是最常见的恶性肿瘤之一,其发病机制仍未完全明了。目前认为DNA甲基化导致转录抑制是恶性肿瘤发生的重要机制之一。E-cadherin能抑制肿瘤的浸润和转移,被公认为是浸润、转移抑制基因。结肠癌常表现有E-cadherin基因失活。本研究通过检测人结肠癌细胞株HT-29中E-cadherin基因表达及甲基化状态,初步探讨结肠癌的发病机制。方法:光镜观察5-杂氮-2'-脱氧胞苷(5-Aza-CdR)干预前后细胞形态学变化;免疫细胞化学及RT-PCR检测不同浓度5-Aza-CdR干预对HT-29细胞中E-cadherin蛋白及mRNA表达的影响;甲基化特异性PCR(MSP)分析细胞中E-cadherin基因甲基化状态。结果:5-Aza-CdR干预能使其甲基化的E-cadherin基因重新表达;免疫细胞化学染色检测1μmol/L5-Aza-CdR干预24h后细胞E-cadherin阳性率由(21±7)%提高到5μmol/L5-Aza-CdR干预时的(39±13)%;E-cadherin基因在HT-29细胞中有甲基化修饰。结论:E-cadherin基因启动子区异常甲基化是结肠癌发生、发展的重要机制之一,...     

Trends in in-patient Hospital Utilization and Surgical Procedures for Breast,Prostate, Lung and Colorectal Cancers in Canada

Objective: To analyse population-based trends of in-patient surgical procedures for breast (female), prostate, lung and colorectal cancers. Methods: The Hospital Morbidity Files supplied hospital data and the Canadian Cancer Registry, incidence data. Age-adjusted rates were standardized to the 1991 Canadian population. Results: All four cancers showed major changes in trends of surgical procedures. For breast cancer, the rate of in-patient breast conservation surgery (BCS) increased from 1981 to the early 1990s while the rate of mastectomy decreased. Because day surgery was not included, the subsequent in-patient BCS rate stayed level. For prostate cancer, the rate of transurethral prostatectomy was initially high but decreased after 1990, while the rate of radical prostatectomy increased rapidly, only minimally affected by the PSA-related peak in incidence. The lung cancer lobectomy rate in men remained at 10/100,000 after 1986, but in women rose from 3/100,000 to 7/100,000, reflecting increasing lung cancer incidence. For colorectal cancer, right hemicolectomies and anterior resections increased, especially in men. Conclusions: Surgery trends reflected changes in incidence and treatment preferences. Canadian trends were generally similar to US trends, although the timing of some of the changes differed. Canadians tended to use less invasive procedures such as BCS and anterior resection.     

Processed meat consumption and risk of cancer: a multisite case–control study in Uruguay

Background:

The role of processed meat in the aetiology of several cancers was explored in detail.

Methods:

In the time period 1996–2004, a multisite case–control study was conducted in Montevideo, Uruguay. The study included 6 060 participants (3 528 cases and 2 532 controls) corresponding to cancers of the oral cavity, pharynx, oesophagus, stomach, colon, rectum, larynx, lung, female breast, prostate, urinary bladder, and kidney (renal cell carcinoma only).

Results:

The highest odds ratios (ORs) were positively associated with cancers of the colon, rectum, stomach, oesophagus, and lung. With the exception of renal cell carcinoma, the remaining cancer sites were significantly associated with elevated risks for processed meat consumption. Furthermore, mortadella, salami, hot dog, ham, and salted meat were strongly associated with risk of several cancer sites.

Conclusion:

It could be concluded that processed meat intake could be a powerful multiorgan carcinogen.     

Cancer surveillance behaviors and psychosocial factors among long‐term survivors of breast cancer

BACKGROUND:

Little is known about cancer surveillance (mammography, clinical breast examination, and pelvic examination) behaviors in long‐term (9‐16 years) breast cancer survivors. This report describes the relation of these behaviors to demographic and clinical characteristics, psychological symptoms, body satisfaction, and social support.

METHODS:

Survivors who had participated in Cancer and Leukemia Group B treatment Trial 8541 completed a survey that included questions on breast cancer surveillance and pelvic examination, psychological well being, body satisfaction, and social support.

RESULTS:

The participation rate was 78% and included 245 breast cancer survivors. Survivors (n = 107; 44%) reported completing breast cancer surveillance (mammography and clinical breast examination) and completing pelvic examination (n = 162; 68%) within recommended guidelines. There were no significant associations between breast cancer surveillance and breast cancer anxiety, depression, stressful life events, body satisfaction, social support, or demographic characteristics. Survivors within recommended guidelines for pelvic examinations were younger (P = .05), married (P = .003), had health insurance (P = .004), and had lower depression scores (P = .005) than survivors who underused or overused pelvic examination. In addition, survivors within recommended pelvic examination guidelines had significantly lower levels of breast cancer anxiety (P = .03) compared with survivors who underused pelvic examination.

CONCLUSIONS:

Many long‐term breast cancer survivors were not within recommended cancer surveillance guidelines. Private health insurance was associated with following recommendations for pelvic examinations, although such a relation did not exist for breast cancer surveillance. The results of this study have implications for the development of educational programs to improve cancer surveillance among the growing population of long‐term breast cancer survivors. Cancer 2009. © 2009 American Cancer Society.     

Rationale and design of the National Program of Cancer Registries' breast, colon, and prostate cancer patterns of care study

Background: Investigators from the Centers for Disease Control and Prevention (CDC), National Program of Cancer Registries (NPCR), are collaborating with public health professionals from seven states and the District of Columbia to conduct the Patterns of Care study to assess the quality of cancer data and to determine whether stage-specific treatments are being carried out. Methods: To assess the quality and completeness of cancer care data in the United States, trained staff from the Patterns of Care study are abstracting medical records to obtain detailed clinical data on treatment, tumor characteristics, stage at diagnosis, and demographics of representative samples of patients diagnosed with breast, colon, and prostate cancer. Altogether staff from each of the eight participating cancer registries will abstract 500 cases of breast, prostate, and colon/rectum/anus cancer for the CONCORD study and an additional 150 cases of localized breast cancer, 100 cases of stage III colon cancer, and 100 cases of localized prostate cancer for the Patterns of Care study. Chi-square tests will be used to compare routine registry data with re-abstracted data. The investigators will use logistic regression techniques to describe the characteristics of patients with localized breast and prostate cancer and stage III colon cancer. Age, race, sex, type of insurance, and comorbidity will be examined as predictors of the use of those treatments that are consistent with consensus guidelines. The investigators plan to use data from the CONCORD study to determine whether treatment factors are the reason for the reported differences between relative survival rates in the United States and Europe. Conclusions Results from the methodology used in the Patterns of Care study will provide, for the first time, detailed information about the quality and completeness of stage and treatment data that are routinely collected by states participating in the NPCR. It will add significantly to our understanding of factors that determine receipt of treatment in compliance with established guidelines. As part of the CONCORD study, it will also examine differences in survival among cancer patients with breast, prostate, and colon/rectum/anus cancers in the United States and Europe.     

Conundrums in screening for cancer

Screening for cancer has to be carefully organized for maximum effectiveness, and introduced in full understanding of the natural history of the disease. There are major potential harms as well as benefits from screening. The current state of art for breast, cervix and prostate cancer screening is reviewed, only for breast and cervix are policies of screening in the population justified.     

Decreasing the cancer burden in developing countries: concerns and recommendations

Although the close of the 20th century witnessed advances in cancer detection and treatment, cancer morbidity and mortality rates steadily increase across the globe within the 21st century. The majority of this cancer burden can be found in underdeveloped and developing countries. A growing concern can be seen regarding this issue, with the research community as well as governmental and non-governmental organizations considering efforts that need to be developed and implemented. In this article, we propose several strategies to reduce cancer burden in developing countries that involve not only governmental and non-governmental organizations in such developing countries but also the research community. Such measures may prove helpful in gaining a better understanding of cancer burden and assist in clinical decision making and the design of prevention strategies for developing countries.     

Clinical delivery of intensity modulated conformal radiotherapy for relapsed or second-primary head and neck cancer using a multileaf collimator with dynamic control

Background and purpose: Concave dose distributions generated by intensity modulated radiotherapy (IMRT) were applied to re-irradiate three patients with pharyngeal cancer.

Patients, materials and methods: Conventional radiotherapy for oropharyngeal (patients 1 and 3) or nasopharyngeal (patient 2) cancers was followed by relapsing or new tumors in the nasopharynx (patients 1 and 2) and hypopharynx (patient 3). Six non-opposed coplanar intensity modulated beams were generated by combining non-modulated beamparts with intensities (weights) obtained by minimizing a biophysical objective function. Beamparts were delivered by a dynamic MLC (Elekta Oncology Systems, Crawley, UK) forced in step and shoot mode.

Results and conclusions: Median PTV-doses (and ranges) for the three patients were 73 (65–78), 67 (59–72) and 63 (48–68) Gy. Maximum point doses to brain stem and spinal cord were, respectively, 67 Gy (60% of volume below 30 Gy) and 32 Gy (97% below 10 Gy) for patient 1; 60 Gy (69% below 30 Gy) and 34 Gy (92% below 10 Gy) for patient 2 and 21 Gy (96% below 10 Gy) at spinal cord for patient 3. Maximum point doses to the mandible were 69 Gy for patient 1 and 64 Gy for patient 2 with, respectively, 66 and 92% of the volume below 20 Gy. A treatment session, using the dynamic MLC, was finished within a 15-min time slot.