荧光素酶标记人胃癌细胞裸鼠原位移植模型的建立

目的建立荧光素酶标记人胃癌原位异种移植模型。方法将萤火虫荧光素酶作为标记基因导入人胃癌MGC803细胞,建立稳定表达荧光素酶的细胞,将其接种裸鼠胃壁浆膜下,建立胃癌裸鼠原位肿瘤模型。用活体荧光成像系统检测肿瘤的发生发展,并进行小动物超声影像和病理学分析。结果裸鼠原位成瘤率为100%,活体荧光成像观察发现在接种第7天,就可以观察到肿瘤发光。21 d后肿瘤进入对数生长期,28 d后肿瘤出现明显坏死,平均荧光光子数呈现下降趋势。超声成像发现小鼠胃部有直径为8.39 mm,面积为28.92 mm2瘤块。结论荧光素酶标记可以实时监测原位异种移植人胃癌生长状况。     

人肝癌原位移植转移模型特性实验研究

目的　建立人肝癌细胞系HCC-9724(简称H)淋巴结转移模型,研究肿瘤转移机理。方法　采用裸鼠肝脏原位移植法,接种肿瘤细胞,取其淋巴结转移灶反复肝内接种,连续传三代后,观察其转移特性,采用SABC法测定淋巴结中nm23和Ⅳ型胶原酶表达。结果　裸鼠原位接种50d,肝内长出约1.7cm×6.0cm大小的肿瘤,呈分叶状,质地较软,周围血供丰富,瘤组织与邻近脏器粘连,有明显的浸润和转移,经裸鼠三次筛选后肿瘤潜伏期短(15d),瘤体大,形成广泛的肠系膜淋巴结转移,淋巴结中Ⅳ型胶原酶表达呈强阳性;而nm23呈弱阳性。结论　采用裸鼠肝原位移植法,反复筛选,获得了人肝癌淋巴结高转移模型。     

人胰腺癌裸鼠异种移植瘤模型的生物发光成像和超声成像比较

目的利用荧光素酶基因标记的人胰腺癌细胞株Capan-2建立胰腺癌裸鼠移植模型,评价生物发光和小动物超声成像在移植瘤模型建立中的作用。方法将表达荧光素酶基因的真核表达载体转入人胰腺癌细胞Capan-2,将1×106人胰腺癌细胞悬液分别接种于裸鼠胰腺和右后肢皮下,使其成瘤。生物发光成像和小动物超声成像系统观察肿瘤的生长情况。结果肿瘤细胞原位移植成功率为75%,皮下移植成功率为100%。生物发光成像系统在肿瘤细胞原位接种第7天,可以观察到肿瘤发光;小动物超声成像系统在肿瘤细胞皮下接种第7天,可以测量肿瘤的大小,但在肿瘤细胞原位接种的第7天不能测量肿瘤的大小。另外肿瘤细胞在裸鼠皮下生长的速度比原位生长速度快3倍左右。结论生物发光成像系统更适用于肿瘤早期监测,为深入研究胰腺癌的发生发展、侵袭转移机制提供理想工具。     

用于活体成像的小鼠肺癌移植瘤模型的建立

本研究旨在建立可用于活体成像的小鼠肺癌移植瘤模型。利用脂质体将荧光素酶表达载体pGL4.17(luc2/neo)转染至人非小细胞肺癌细胞株A549,经G418筛选获得稳定表达荧光素酶的细胞克隆。根据体外生物发光情况及细胞的生长特性,从中挑选合适克隆,进行裸鼠皮下接种,SCID鼠尾静脉接种,建立肺癌移植瘤模型。利用活体成像系统监测肿瘤的生长转移情况,并用切片HE染色进一步验证小鼠模型移植瘤的原位成瘤和转移能力。实验结果表明:本研究成功地构建了可用于活体成像的小鼠肺癌移植瘤模型,模型稳定可靠、直观、灵敏,为肿瘤生长转移机制的研究及抗肿瘤药物的研发提供了重要工具。     

阿霉素载药微球在免疫缺陷大鼠肝脏原位肿瘤组织内缓释作用与长效抗肿瘤活性研究

目的:建立免疫缺陷大鼠肝脏原位肿瘤模型,以阿霉素为模型药物,在肿瘤组织注射吸附有阿霉素的载药微球,建立肿瘤组织内抗肿瘤药物缓释与长效作用的研究方法。方法:利用MHCC-97H高侵袭肝细胞癌细胞系在免疫缺陷裸鼠皮下成瘤后,解剖瘤块并切割,种植于免疫缺陷大鼠肝脏原位;进行开腹给药,将阿霉素载药微球精准注射进大鼠肝脏原位肿瘤组织中;收集大鼠血液、肿瘤组织标本等,检测药物在大鼠体内特别是肿瘤组织内的留存情况,最后进行PET/CT小动物活体成像,确定阿霉素载药微球在免疫缺陷大鼠肝脏原位肿瘤组织内缓释作用与长效抗肿瘤活性。结果:通过大鼠肝脏原位接种肝细胞癌瘤块可建立免疫缺陷大鼠肝脏原位肿瘤模型;使用阿霉素载药微球对病灶进行精准给药可实现阿霉素载药微球在体内的缓释作用;索拉非尼(Sorafenib)联用阿霉素载药微球可更显著地抑制大鼠肝脏原位肿瘤的生长。结论:建立了免疫缺陷大鼠肝脏原位肿瘤模型,建立了肿瘤组织内抗肿瘤药物缓释与长效作用的研究方法。     

建立分泌型荧光素酶基因标记的原位肝癌模型及用于干扰素β基因治疗评价

旨在建立一种分泌型荧光素酶基因标记的小鼠原位移植型肝癌模型并观察其对干扰素β基因治疗的反应。首先建立稳定表达分泌型荧光素酶Gluc(Gaussia princeps luciferase)的小鼠肝癌细胞Hepa 1-6/Gluc;将该细胞通过脾注射至C57BL/6小鼠肝脏建立原位移植型肝癌模型,通过检测外周血Gluc活性监测小鼠体内肿瘤生长情况;用此模型观察水动力注射干扰素β质粒DNA的抗肿瘤效果。结果表明,通过脾注射Gluc基因标记的Hepa 1-6细胞可以建立小鼠原位移植型肝癌模型;外周血Gluc活性可以有效反映体内接种肿瘤细胞的数量和肿瘤的生长情况;通过监测外周血Gluc活性可灵敏反映干扰素β基因治疗对肿瘤生长的抑制作用。本研究表明,利用Gluc为报告基因建立的小鼠原位移植型肝癌模型可以体外实时监测肿瘤的生长情况,并能灵敏可靠地用于抗肿瘤治疗效果的评价。     

荧光素酶标的人肝癌细胞裸鼠异种移植瘤模型的生物发光成像和PET-CT成像比较

目的利用荧光素酶基因标记的人肝癌细胞株BEL-7402建立裸鼠肝原位移植模型,及小鼠肝原位移植模型的生物发光和小动物PET-CT成像的比较。方法构建表达荧光素酶基因的真核表达载体并将其转入人肝癌细胞BEL-7402,经梯度浓度G418筛选获得稳定表达荧光素酶基因的细胞克隆并扩大培养。BALB/cA-nu裸鼠肝门静脉接种5×105个发光细胞使其成瘤,活体荧光成像和小动物PET-CT成像系统观察肿瘤的生长情况。结果获得了稳定表达Luc的人肝癌细胞株,将其接种到裸鼠体内,活体荧光成像系统观察发现能够成瘤,小动物PET-CT影像观察发现小鼠肝脏边缘对18 F-FDG有高摄取区域。结论利用荧光素酶基因标记的人肝癌细胞BEL-7402成功建立了原位肝癌裸鼠模型,小动物活体成像结合小动物PET-CT技术为原位肿瘤模型的建立提供了一种新的可靠的技术,为进一步研究肝癌生长转移机制和药物开发提供了新的有用工具。     

肝细胞癌原位与皮下PDX模型的方法学比较分析研究

目的构建肝细胞癌(hepatocellular carcinoma,HCC)原位与皮下人源肿瘤异种移植(patient-derived xenografts,PDX)模型,并比较分析两者生长和病理学特点。方法收集肝癌患者的新鲜肿瘤组织,接种肝和皮下组织,比较分析两者生长特性、病理特征、成瘤率和成瘤时间。结果本次研究成功构建肝癌原位和皮下PDX模型,两者与患者原发肿瘤病理特征一致,其中原位和皮下综合成瘤率分别为50%(3/6)和20%(3/15),平均成瘤时间为30 d和68 d。结论肝癌原位PDX模型成瘤率高,对于难生长肿瘤提供了一个新的建模方法,皮下成瘤操作和观察较为简单,在具体科研实践中应根据情况使用合适方法。它们为深入探索HCC的发病机制,及药物筛选提供有效的动物模型。     

裸小鼠肝癌原位移植模型的建立

目的建立一种BALB/c裸小鼠肝癌原位移植模型。方法采用异氟烷气化对实验动物进行全身麻醉,分别用"包埋法"和"夹心法"建立BALB/c裸小鼠肝癌原位移植瘤模型。手术后用小动物活体成像系统对肿瘤组织的生长情况进行检测,4周后对肝及肿瘤组织进行组织病理学检查。结果采用夹心法建立的肝癌原位移植BALB/c裸小鼠模型,具有操作时间短,难度低,成瘤率高的特点,肿瘤组织生长良好,在腹腔内未出现肿瘤广泛种植现象,组织病理学检查无异常,动物死亡率低等特点。结论与包埋法相比,夹心法更具优势,可快速制备大批量小鼠肝癌原位移植模型,为肝癌原位药效学及其他研究提供更便利的平台。     

近交系小鼠移植性肝癌模型建立及对比分析

目的：通过对比分析选择建立原位移植性肝癌模型的最佳小鼠品系。方法选取C57、C3H和BALB／c各10只小鼠分别作为模型组Ⅰ、模型组Ⅱ和模型组Ⅲ,沿腹中线开腹后将H22细胞接种到各模型组小鼠肝脏实质内。于注射后第15天剖腹探查,观察各组成瘤率,测量腹水量和肿瘤体积,并进行肿瘤病理学分析。结果三组小鼠存活率均为100％,15天后三组小鼠均产生腹水,但三组腹水量之间不具有统计学差异。模型组Ⅰ小鼠肝癌移植成功率为100％,高于模型组Ⅱ的60％和模型组Ⅲ的30％。模型组Ⅰ小鼠肝脏肿瘤全部为大块紧实灰白色病灶,其肿瘤平均体积显著大于模型组Ⅱ和模型组Ⅲ（ P＜0.05）。病理结果证实三组小鼠肝脏的灰白色病灶均为原位肝细胞癌。结论 C57小鼠是复制原位移植性肝癌模型较为理想的实验动物,为今后研究原位肝癌的发病机制提供良好的实验平台。     

Tumor size,leukocyte adherence inhibition and serum levels of tumor antigen in dogs with the canine transmissible venereal sarcoma

Summary Tumor antigen (TA) associated with the canine transmissible venereal sarcoma (CTVS) was detected in the sera of dogs bearing the tumor. Rabbit antisera specific for tumor antigen and 3 M KCl extracts of CTVS cells were used in both a competitive enzyme-linked immunosorbent assay (ELISA) and antigen-capture ELISA to quantify levels of circulating TA. In a study of 29 dogs bearing the transplanted CTVS, levels of circulating TA correlated positively with tumor volume. In a longitudinal study of four dogs receiving a transplant of 10⁸ viable CTVS cells, circulating CTVS antigen was detected transiently 2 days after transplantation, while persistent levels of TA associated with increasing tumor volume were demonstrable 19–34 days after transplantation. In three of four tumor-bearing dogs, levels of serum TA correlated inversely with values obtained with peripheral blood leukocytes in the leukocyte adherence inhibition (LAI) assay; elevated levels of circulating TA found in dogs with large (>7 cm³) tumors were associated with decreased LAI reactivity of peripheral blood leukocytes. TA could not be detected in sera 48–72 h after surgical removal of CTVS whereas LAI reactivity of peripheral blood leukocytes to CTVS antigen rebounded 1–3 weeks following tumor excision. Results of this study support the use of the competitive ELISA and LAI techniques in assessing levels of circulating tumor antigen, tumor burden and tumor-specific immunity.Supported by grants from the American Kennel Club, National Institutes of Health (CA23 469) and Funds for Research on Canine Diseases provided by the 1963 Connecticut Legislature     

Regulation of leukocyte glass adherence and tube leukocyte adherence inhibition (LAI) reactivity by serum factors in dogs with progressing or spontaneously regressing canine transmissible venereal sarcoma (CTVS)

Summary We examined the regulation of leukocyte glass adherence and tube leukocyte adherence inhibition (LAI) reactivity by serum factors in dogs with regressing or progressing canine transmissible venereal sarcomas (CTVS). Both regressor and progressor peripheral blood leukocytes (PBL), draining and nondraining lymph node cells (LNC), and splenic leukocytes were significantly responsive to CTVS antigen extract in tube LAI. In contrast, a significant decrease in basal glass adherence of progressor PBL, draining and nondraining LNC, and splenic leukocytes was observed. Normal glass adherence was restored to progressor leukocytes by extensive washing with warm serum-free media, while significant tube LAI responsiveness to CTVS antigen extract was maintained. Preincubation of regressor PBL and LNC with progressor sera in two-stage tube LAI decreased the basal glass adherence of treated leukocytes. This effect of progressor sera was heat labile, a characteristic of CTVS antigen. Collectively, these findings suggest that progessor leukocytes and progressor sera treated regressor leukocytes were activated by interaction with serum CTVS antigen and thus behaved in tube LAI as stimulated cells, even in the absence of CTVS antigen. Regressor but not progressor sera were shown to contain anti-CTVS IgG with specific arming activity for normal dog PBL, but not LNC in two-stage tube LAI. The nonadherent response of peripheral blood neutrophils in two-stage tube LAI was proportional to the concentration of arming IgG, whereas no change was observed in glass adherence of PBL. The results of this study define the role of progressor and regressor serum factors in the mechanism of tube LAI and demonstrate a relationship between leukocyte glass adherence and the clinical course of CTVS. These findings show that tube LAI is a simple and reproducible measure of active factors in the immune response to a tumor.This investigation was supported in part by grant, CA-23469, from the National Cancer Institute, DHHS, and is submitted as Scientific Contribution No. 1051, Storrs Agricultural Experiment Station, University of Connecticut, Storrs, CT 06268 USA     

Amplification of lymph node cell tube leukocyte adherence inhibition (LAI) reactivity by leukocyte adherence inhibition factor (LAIF)

This investigation examines the immunologic basis for specific antigen-induced tube leukocyte adherence inhibition (LAI) reactivity of draining lymph node cells (LNC) from dogs with canine transmissible venereal sarcoma (CTVS). CTVS regressor LNC, macrophage-depleted LNC, and enriched T lymphocyte fractions, but not enriched B lymphocyte fractions, were specifically reactive to CTVS antigen extract in direct tube LAI. In addition, regressor LNC amplified tube LAI responses by generating supernatants with leukocyte adherence inhibition factor (LAIF) activity for normal dog indicator LNC and enriched peripheral blood mononuclear cells (PBMC) in an indirect tube LAI assay. However, macrophage-depleted LNC and enriched T lymphocyte fractions failed to generate supernatants with LAIF activity, suggesting that macrophage accessory cells play a central role in the amplification of tube LAI. Interestingly, CTVS regressor peripheral blood leukocytes (PBL) and PBMC, which were specifically reactive in direct tube LAI, also failed to generate supernatants with LAIF activity. These findings demonstrate a distinction between LAIF-mediated amplification and direct tube LAI reactivity, and suggest that leukocyte populations with differing cellular proportions and from different immunologic compartments may participate in tube LAI via different mechanisms.     

CRISPR/Cas9在肿瘤治疗中的研究进展

CRISPR/Cas9技术自从出现以来便迅速应用于肿瘤研究。在肿瘤发生的机理研究中,CRISPR/Cas9可用于研究单核苷酸突变、染色体异位等因素在肿瘤发生中的作用机制,同时也可以用于肿瘤细胞中功能缺陷基因的筛选。在肿瘤治疗方法的研究中,CRISPR/Cas9主要用于诱发机制比较清晰且诱因为病毒的肿瘤类型,例如鼻咽癌、宫颈癌等,通过对相应病毒的基因进行编辑从而抑制其致癌作用。利用CRISPR/Cas9技术还可以加速新肿瘤治疗靶点基因的发现。尽管发展和应用十分迅速,但是CRISPR/Cas9在肿瘤研究和治疗中的作用仍然受多种因素的限制,包括Cas9和sgRNA的输送效率、脱靶效应以及安全性和成本等。对CRISPR/Cas9在肿瘤研究中的应用进展进行了综述,以期为肿瘤发生、转移机制和肿瘤治疗等方面的研究提供参考。     

An approach to confirmatory testing of subpopulations in clinical trials

In oncology studies with immunotherapies, populations of “super‐responders” (patients in whom the treatment works particularly well) are often suspected to be related to biomarkers. In this paper, we explore various ways of confirmatory statistical hypothesis testing for joint inference on the subpopulation of putative “super‐responders” and the full study population. A model‐based testing framework is proposed, which allows to define, up‐front, the strength of evidence required from both full and subpopulations in terms of clinical efficacy. This framework is based on a two‐way analysis of variance (ANOVA) model with an interaction in combination with multiple comparison procedures. The ease of implementation of this model‐based approach is emphasized and details are provided for the practitioner who would like to adopt this approach. The discussion is exemplified by a hypothetical trial that uses an immune‐marker in oncology to define the subpopulation and tumor growth as the primary endpoint.     

猕猴B病毒gC蛋白特异性抗原表位的合成和表达

目的获得B病毒gC蛋白的特异性表位抗原。方法利用长片段基因合成的方法,合成B病毒C蛋白的特性抗原表位基因,将该基因连接到pMAL-5x载体,转化到BL21受体菌进行表达,并纯化表达产物。结果成功的获得了B病毒gC蛋白的特异性抗原蛋白,该蛋白以可溶的形式表达。结论利用原核表达系统,可以产生B病毒gC蛋白的可溶性抗原,可以作为B病毒的检测抗原。     

Dynamic BH3 profiling identifies active BH3 mimetic combinations in non-small cell lung cancer

Conventional chemotherapy is still of great utility in oncology and rationally constructing combinations with it remains a top priority. Drug-induced mitochondrial apoptotic priming, measured by dynamic BH3 profiling (DBP), has been shown in multiple cancers to identify drugs that promote apoptosis in vivo. We therefore hypothesized that we could use DBP to identify drugs that would render cancers more sensitive to conventional chemotherapy. We found that targeted agents that increased priming of non-small cell lung cancer (NSCLC) tumor cells resulted in increased sensitivity to chemotherapy in vitro. To assess whether targeted agents that increase priming might enhance the efficacy of cytotoxic agents in vivo as well, we carried out an efficacy study in a PC9 xenograft mouse model. The BH3 mimetic navitoclax, which antagonizes BCL-xL, BCL-w, and BCL-2, consistently primed NSCLC tumors in vitro and in vivo. The BH3 mimetic venetoclax, which electively antagonizes BCL-2, did not. Combining navitoclax with etoposide significantly reduced tumor burden compared to either single agent, while adding venetoclax to etoposide had no effect on tumor burden. Next, we assessed priming of primary patient NSCLC tumor cells on drugs from a clinically relevant oncology combination screen (CROCS). Results confirmed for the first time the utility of BCL-xL inhibition by navitoclax in priming primary NSCLC tumor cells and identified combinations that primed further. This is a demonstration of the principle that DBP can be used as a functional precision medicine tool to rationally construct combination drug regimens that include BH3 mimetics in solid tumors like NSCLC.Subject terms: Non-small-cell lung cancer, Apoptosis, Predictive markers     

Metabolic mapping with bioluminescence: basic and clinical relevance

This review is focused on metabolic mapping in biological tissue with quantitative bioluminescence and single photon imaging. Metabolites, such as ATP, glucose and lactate, can be imaged quantitatively and within microscopic dimensions in cryosections from shock frozen biological specimens using enzyme reactions and light emission by luciferases. The technique has been applied in numerous targets and models of experimental biomedical research, such as multicellular spheroids, various organs of laboratory animals in a physiological or pathophysiological state, and even in plant seeds. Among numerous other aspects, data obtained with this method have contributed to the elucidation of mechanisms that are involved in the development of necrosis in multicellular spheroids. The combination of the bioluminescence technique with immunohistochemistry, autoradiography or in situ hybridization can considerably reduce ambiguities in the interpretation of the experimental results. Although, an invasive technique, bioluminescence imaging has been used most intensively in clinical oncology using tumor biopsies taken at the first diagnosis of the disease. It has been shown for squamous cell carcinomas of the head and neck and of the uterine cervix that accumulation of high levels of lactate in the primary lesions is associated with a high risk of metastasis formation and a reduced overall and disease-free patient survival. Thus, metabolic imaging can provide additional information on the degree of malignancy and the prognosis of tumors which may help the oncologist in improving specific treatment approaches for each individual malignant disease. Last but not least, metabolic mapping in clinical oncology has stimulated a number of investigations in basic cancer research on mechanisms that underlie the correlation between tumor metabolism and malignancy.     

Global sensitivity analysis and model-based reactive scheduling of targeted cancer immunotherapy

Intra-patient variability is a key challenge in cancer treatment. This makes it necessary to find the factors affecting tumor growth and accordingly schedule therapies over the treatment horizon for the patient. In this work, model-based studies are performed to investigate these issues for optimal immunotherapeutic intervention. Dendritic cell therapy is a targeted immunotherapy where the dendritic cells and its activating agents such as interleukin are engineered, stimulated to recognize and specifically eradicate tumors. A mathematical model that integrates tumor dynamics and dendritic cell therapy is used to perform the analysis. Global sensitivity analysis of the model is done using high dimensional model reduction (HDMR) technique and the key parameters altering the tumor growth are identified. The variations in these key parameters are deemed to result in intra-patient variability during the treatment phase. Then, reactive scheduling is used to schedule dendritic cell interventions with and without interleukin interventions under the varying conditions of the patient. Moreover, the key parameters obtained from HDMR are verified using the reactive scheduling and nominal scheduling approaches. Besides saving costs, the in silico analysis done in this paper may be useful to the oncology community in designing experiments to clinically measure the influential parameters. It can also be used as a decision making tool to determine the required intervention dosage during the treatment.     

A branching-process model for heterogeneous cell populations

A multitype branching-process model is introduced for the growth of heterogeneous cell populations. This model includes events representing mitosis, death, mutation, and conversion from one cell type to another. Formulas for conditioning on interim events, and generalizations allowing parameters to be functions of time or cell counts, are presented. The probability generating function (p.g.f.) is solved approximately in a way that is both accurate and efficient enough to solve important problems in tumor biology. The uses of the p.g.f. in the setting of clinical oncology are described.