Multi-photon Imaging of Tumor Cell Invasion in an Orthotopic Mouse Model of Oral Squamous Cell Carcinoma

Loco-regional invasion of head and neck cancer is linked to metastatic risk and presents a difficult challenge in designing and implementing patient management strategies. Orthotopic mouse models of oral cancer have been developed to facilitate the study of factors that impact invasion and serve as model system for evaluating anti-tumor therapeutics. In these systems, visualization of disseminated tumor cells within oral cavity tissues has typically been conducted by either conventional histology or with in vivo bioluminescent methods. A primary drawback of these techniques is the inherent inability to accurately visualize and quantify early tumor cell invasion arising from the primary site in three dimensions. Here we describe a protocol that combines an established model for squamous cell carcinoma of the tongue (SCOT) with two-photon imaging to allow multi-vectorial visualization of lingual tumor spread. The OSC-19 head and neck tumor cell line was stably engineered to express the F-actin binding peptide LifeAct fused to the mCherry fluorescent protein (LifeAct-mCherry). Fox1^nu/nu mice injected with these cells reliably form tumors that allow the tongue to be visualized by ex-vivo application of two-photon microscopy. This technique allows for the orthotopic visualization of the tumor mass and locally invading cells in excised tongues without disruption of the regional tumor microenvironment. In addition, this system allows for the quantification of tumor cell invasion by calculating distances that invaded cells move from the primary tumor site. Overall this procedure provides an enhanced model system for analyzing factors that contribute to SCOT invasion and therapeutic treatments tailored to prevent local invasion and distant metastatic spread. This method also has the potential to be ultimately combined with other imaging modalities in an in vivo setting.     

利用萤光素酶标记的肿瘤细胞建立肝癌原位移植模型及其活体成像

目的：利用生物发光成像技术非侵入性地监测活体裸鼠原位肝癌发展过程。方法：将包含有萤火虫萤光素酶基因的pCI-neo-Luc载体转染人肝癌HepG2细胞系,筛选获得具有高萤光素酶活性的细胞克隆;利用流式细胞仪对萤光素酶表达的稳定性进行初步研究,并分析细胞的生物发光情况;持续表达萤光素酶的肿瘤细胞培养扩增后被植入裸鼠皮下,2周后以形成的异体瘤作为供体瘤,进行肝脏原位移植手术;对建立的肝癌原位移植模型,用影像学资料显示肿瘤部位,用IVIS成像系统动态监测肿瘤生长情况。结果：体外影像的结果显示,表达萤光素酶细胞的数量与发光强度呈正相关;活体成像的结果显示。成功地建立了萤光素酶标记的原位肝癌动物模型。结论：生物发光成像可以监测活体内肝癌演进过程,为抗肿瘤药物的筛选和评价提供了新的手段和工具。     

Circulating Tumor Cell Composition in Renal Cell Carcinoma

PurposeDue to their minimal-invasive yet potentially current character circulating tumor cells (CTC) might be useful as a “liquid biopsy” in solid tumors. However, successful application in metastatic renal cell carcinoma (mRCC) has been very limited so far. High plasticity and heterogeneity of CTC morphology challenges currently available enrichment and detection techniques with EpCAM as the usual surface marker being underrepresented in mRCC. We recently described a method that enables us to identify and characterize non-hematopoietic cells in the peripheral blood stream with varying characteristics and define CTC subgroups that distinctly associate to clinical parameters. With this pilot study we wanted to scrutinize feasibility of this approach and its potential usage in clinical studies.ResultsWe detected CTC with epithelial, mesenchymal, stem cell-like or mixed-cell characteristics at different time-points during anti-angiogenic therapy. The presence and quantity of N-cadherin-positive or CD133-positive CTC was associated with inferior PFS. There was an inverse correlation between high expression of HIF1A, VEGFA, VEGFR and FGFR and the presence of N-cadherin-positive and CD133-positive CTC.ConclusionsPatients with mRCC exhibit distinct CTC profiles that may implicate differences in therapeutic outcome. Prospective evaluation of phenotypic and genetic CTC profiling as prognostic and predictive biomarker in mRCC is warranted.     

直接注射法制作ICR小鼠肝癌原位移植瘤模型

目的：培养鼠肝癌H22细胞,直接注射法制作ICR小鼠肝癌原位移植瘤,为后续实验奠定基础。方法：鼠肝癌H22细胞体外培养,将调整好的对数生长期的肝癌细胞直接注射小鼠肝脏,2周后解剖观察,并进行组织HE染色。结果：所有实验小鼠均可见肿瘤生长,HE染色示肝细胞肝癌。结论：直接注射法制作ICR小鼠肝癌原位移植瘤模型简便易行,值得推广应用。     

肝细胞癌循环肿瘤细胞标志物及检测方法研究进展

肝细胞癌(hepatocellular carcinoma, HCC)在中国是一种高发病率和高死亡率的恶性肿瘤。肿瘤切除、肝移植是治疗该病最有效的手段,但术后的高复发率和高转移率是影响患者预后的重要因素。外周血循环肿瘤细胞(circulating tumor cells, CTCs)是导致肝细胞癌术后复发和转移的必要因子。综述了CTCs的标记物——磷脂酰肌醇蛋白聚糖-3、转铁蛋白受体、甲胎蛋白、α-L岩藻糖苷酶、上皮细胞粘附因子、高尔基蛋白73和异常凝血酶原等,以及利用这些标记物检测CTCs的特异性和灵敏度,以期为肝细胞癌转移的早期检测、术后的复发、预后评估和选择治疗方案等提供依据。     

直接注射法制作ICR 小鼠肝癌原位移植瘤模型

目的:培养鼠肝癌H22细胞,直接注射法制作ICR小鼠肝癌原位移植瘤,为后续实验奠定基础。方法:鼠肝癌H22细胞体外培养,将调整好的对数生长期的肝癌细胞直接注射小鼠肝脏,2周后解剖观察,并进行组织HE染色。结果:所有实验小鼠均可见肿瘤生长,HE染色示肝细胞肝癌。结论:直接注射法制作ICR小鼠肝癌原位移植瘤模型简便易行,值得推广应用。     

Multimodal Imaging of Orthotopic Mouse Model of Endometrial Carcinoma

Background

Orthotopic endometrial cancer models provide a unique tool for studies of tumour growth and metastatic spread. Novel preclinical imaging methods also have the potential to quantify functional tumour characteristics in vivo, with potential relevance for monitoring response to therapy.

Methods

After orthotopic injection with luc-expressing endometrial cancer cells, eleven mice developed disease detected by weekly bioluminescence imaging (BLI). In parallel the same mice underwent positron emission tomography–computed tomography (PET-CT) and magnetic resonance imaging (MRI) employing ¹⁸F-fluorodeoxyglocose (¹⁸F-FDG) or ¹⁸F- fluorothymidine (¹⁸F-FLT) and contrast reagent, respectively. The mice were sacrificed when moribund, and post-mortem examination included macroscopic and microscopic examination for validation of growth of primary uterine tumours and metastases. PET-CT was also performed on a patient derived model (PDX) generated from a patient with grade 3 endometrioid endometrial cancer.

Results

Increased BLI signal during tumour growth was accompanied by increasing metabolic tumour volume (MTV) and increasing MTV x mean standard uptake value of the tumour (SUV_mean) in ¹⁸F-FDG and ¹⁸F-FLT PET-CT, and MRI conspicuously depicted the uterine tumour. At necropsy 82% (9/11) of the mice developed metastases detected by the applied imaging methods. ¹⁸F-FDG PET proved to be a good imaging method for detection of patient derived tumour tissue.

Conclusions

We demonstrate that all imaging modalities enable monitoring of tumour growth and metastatic spread in an orthotopic mouse model of endometrial carcinoma. Both PET tracers, ¹⁸F-FDG and ¹⁸F-FLT, appear to be equally feasible for detecting tumour development and represent, together with MRI, promising imaging tools for monitoring of patient-derived xenograft (PDX) cancer models.     

Detection of Circulating Tumor Cell Subpopulations in Patients with Head and Neck Squamous Cell Carcinoma (HNSCC)

Background

Since image based diagnostic tools fail to detect early metastasis in head and neck squamous cell carcinoma (HNSCC) it is crucial to develop minimal invasive diagnostic methods. A promising approach is to identify and characterize circulating tumor cells (CTC) in the peripheral blood of HNSCC patients. In this pilot study, we assessed which non-hematopoietic cell types are identifiable and whether their numbers differ in pre- and postoperative blood samples.

Methods

20 ml citrated peripheral blood was taken from 10 HNSCC patients before and after curative resection. CTC were enriched using density gradient centrifugation. CTC presence was verified by multi-immunofluorescence staining against cytokeratin (CK; epithelial), N-cadherin (mesenchymal); CD133 (stem-cell), CD45 (hematopoietic) and DAPI (nucleus). Individual cell type profiles were analyzed.

Results

We were able to detect cells with epithelial properties like CK+/N-cadherin−/CD45− and CK+/CD133−/CD45− as well as cells with mesenchymal features such as N-cadherin+/CK−/CD45− and cells with both characteristics like N-cadherin+/CK+/CD45−. We also observed cells showing stem cell-like features like CD133+/CK−/CD45− and cells with both epithelial and stem cell-like features such as CD133+/CK+/CD45−. The number of CK positive cells (p = 0.002), N-cadherin positive cells (p = 0.002) and CD133 positive cells (p = 0.01) decreased significantly after resection. Kaplan-Meier test showed that the survival was significantly shorter when N-cadherin+ cells were present after resection (p = 0.04; 474 vs. 235 days; [HR] = 3.1).

Conclusions

This is - to the best of our knowledge- the first pilot study identifying different CTC populations in peripheral blood of HNSCC patients and showing that these individual cell type profiles may have distinct clinical implications.     

Monitoring Prostate Tumor Growth in an Orthotopic Mouse Model Using Three-Dimensional Ultrasound Imaging Technique

Prostate cancer (CaP) is the most commonly diagnosed and the second leading cause of death from cancer in males in USA. Prostate orthotopic mouse model has been widely used to study human CaP in preclinical settings. Measurement of changes in tumor size obtained from noninvasive diagnostic images is a standard method for monitoring responses to anticancer modalities. This article reports for the first time the usage of a three-dimensional (3D) ultrasound system equipped with photoacoustic (PA) imaging in monitoring longitudinal prostate tumor growth in a PC-3 orthotopic NODSCID mouse model (n = 8). Two-dimensional and 3D modes of ultrasound show great ability in accurately depicting the size and shape of prostate tumors. PA function on two-dimensional and 3D images showed average oxygen saturation and average hemoglobin concentration of the tumor. Results showed a good fit in representative exponential tumor growth curves (n = 3; r² = 0.948, 0.955, and 0.953, respectively) and a good correlation of tumor volume measurements performed in vivo with autopsy (n = 8, r = 0.95, P < .001). The application of 3D ultrasound imaging proved to be a useful imaging modality in monitoring tumor growth in an orthotopic mouse model, with advantages such as high contrast, uncomplicated protocols, economical equipment, and nonharmfulness to animals. PA mode also enabled display of blood oxygenation surrounding the tumor and tumor vasculature and angiogenesis, making 3D ultrasound imaging an ideal tool for preclinical cancer research.     

Bioluminescence Imaging Reveals Dynamics of Beta Cell Loss in the Non-Obese Diabetic (NOD) Mouse Model

We generated a mouse model (MIP-Luc-VU-NOD) that enables non-invasive bioluminescence imaging (BLI) of beta cell loss during the progression of autoimmune diabetes and determined the relationship between BLI and disease progression. MIP-Luc-VU-NOD mice displayed insulitis and a decline in bioluminescence with age which correlated with beta cell mass, plasma insulin, and pancreatic insulin content. Bioluminescence declined gradually in female MIP-Luc-VU-NOD mice, reaching less than 50% of the initial BLI at 10 weeks of age, whereas hyperglycemia did not ensue until mice were at least 16 weeks old. Mice that did not become diabetic maintained insulin secretion and had less of a decline in bioluminescence than mice that became diabetic. Bioluminescence measurements predicted a decline in beta cell mass prior to the onset of hyperglycemia and tracked beta cell loss. This model should be useful for investigating the fundamental processes underlying autoimmune diabetes and developing new therapies targeting beta cell protection and regeneration.     

基于活体成像的表达人PSCA抗原的小鼠肿瘤模型的建立

目的:探讨并建立可供药物评价或生物学功能研究的表达人PSCA抗原的荧光素酶小鼠肿瘤模型。方法:克隆人PSCA基因及荧光素酶基因luc,构建真核表达质粒pcDNA-PSCA及pcDNA-luc,共转染RM-1细胞株;照度计检测转染细胞的荧光素酶活性,RT-PCR及流式细胞术检测PSCA的表达,筛选出共表达荧光素酶及人PSCA的RM-PSCA/luc细胞株;将RM-PSCA/luc细胞接种C57BL/6小鼠,观察所致肿瘤的生长情况及小鼠存活状况,并对小鼠进行活体成像检测Luc的表达;采用免疫组织化学染色方法检测人PSCA在小鼠肿瘤组织中的表达。结果:筛选到了稳定共表达Luc及人PSCA抗原的RM-PSCA/luc细胞,接种实验小鼠全部成瘤,肿瘤生长迅速,小鼠平均存活38天;转染荧光素酶基因的肿瘤细胞生物特性稳定,活体成像仪检测到转染荧光素酶细胞在小鼠体内活体成像,荧光素酶表达活性的强弱能够反映肿瘤大小;免疫组织化学染色方法检测到小鼠肿瘤组织PSCA的表达。结论:成功构建了可用于活体成像表达人PSCA抗原的小鼠肿瘤模型,为相关肿瘤药物及疫苗的研发奠定基础。     

Bioluminescence Imaging of an Immunocompetent Animal Model for Glioblastoma

In contrast to commonly reported human glioma xenograft animal models, GL261 murine glioma xenografts recapitulate nearly all relevant clinical and histopathologic features of the human disease. When GL261 cells are implanted intracranially in syngeneic C57BL/6 mice, the model has the added advantage of maintaining an intact immune microenvironment. Stable expression of luciferase in GL261 cells allows non-invasive cost effective bioluminescence monitoring of intracranial tumor growth. We have recently demonstrated that luciferase expression in GL261 cells does not affect the tumor growth properties, tumor cell immunomodulatory cytokine expression, infiltration of immune cells into the tumor, or overall survival of animals bearing the intracranial tumor. Therefore, it appears that the GL261 luciferase glioma model can be useful in the study of novel chemotherapeutic and immunotherapeutic modalities. Here we report the technique for generating stable luciferase expression in GL261 cells and how to study the in vitro and in vivo growth of the tumor cells by bioluminescence imaging.     

LJH-OS人骨肉瘤裸鼠原位移植模型的建立及其生物学特性

用人成骨肉瘤细胞系LJH- OS的传代移植瘤组织作为移植材料,进行胫骨原位移植及皮下移植。结果发现胫骨原位移植的潜伏期较短,生长快。皮下移植瘤呈局限性膨胀性生长,有不完整的纤维包膜,未见肺转移,观察7 周无明显消瘦;而胫骨原位移植瘤浸润基层,无纤维包膜,且发生肺转移,7 周时有明显消瘦。原位移植的裸鼠血清ALP水平高于皮下移植者。说明裸鼠胫骨微环境较皮下组织更适于人骨肉瘤的浸润及转移表达,裸鼠胫骨原位移植模型的恶性生物学行为更接近临床骨肉瘤患者的实际情况,该原位移植模型的建立为骨肉瘤的研究提供了良好的实验模型。     

Isolation of an Insulin-Responsive Preadipose Cell Line and a Mammary Tumor Virus-Producing, Dome-Forming Epithelial Cell Line from a Mouse Mammary Tumor

Two functional tissue culture cell lines, MTD and MTF cell lines, have been isolated from a mouse mammary tumor. MTD cells are epithelial and retain the ability to transport fluid leading to the formation of three-dimensional fluid-filled multicellular structures called "domes" or "hemicysts". Another property of MTD cells is the production of murine mammary tumor virus (MTV). Release of MTV into the culture medium was verified by immunological, electrophoretic and enzymatic analyses. Addition of dexamethasone in the culture medium enhanced both the formation of domes and the production of MTV. Thus, MTD cells retain the morphological and functional properties of the original mammary tumor cells.
MTF cells show the fibroblastic morphology in subconfluent cultures. After reaching confluence, however, these cells gradually accumulated triglycerides in the cytoplasm and eventually assumed the morphology of fat cells. This adipose conversion was greatly enhanced by the presence of insulin in the culture medium. The morphological resemblance of adipose-converted MTF cells to the mammary fat cells suggests that the MTF cell line was derived from the mammary fat pad stroma. These functional cell lines will be useful to study cell differentiation as well as cell-to-cell interactions in the mammary gland.     

Detection of Circulating Tumor Cells and Circulating Tumor Microemboli in Gastric Cancer

PURPOSE: Gastric cancer studies indicated a potential correlation between circulating tumor cells (CTCs) in peripheral blood and tumor relapse/metastasis. The prevalence and significance of circulating tumor microemboli (CTM) in gastric cancer remain unknown. We investigated the prevalence and prognostic value of CTCs and CTM for progression-free survival (PFS) and overall survival (OS) in gastric cancer patients. METHODS:Eighty-one gastric cancer patients consented to provide 5 ml of peripheral blood before systematic therapy. CTCs and CTM were isolated using isolation by size of epithelial tumor cells and characterized by cytopathologists. For 41 stage IV gastric cancer patients, CTM was investigated as a potential biomarker to predict prognosis. RESULTS:CTCs were detected in 51 patients; the average count was 1.81. In clinical stage I, II, III, and IV patients, the average CTC counts were 1.40, 0.67, 1.24, and 2.71, respectively. CTM were detected in 3 of 33 clinical stage I to IIIb patients, at an average of 0.12 (0-2). CTM were detected in 13 of 53 clinical stage IIIc to IV patients, at an average of 1.26 (0-22). In stage IV patients, CTM positivity correlated with the CA125 level. PFS and OS in CTM-positive patients were significantly lower than in CTM-negative patients (P < .001). CTM positivity was an independent factor for determining the PFS (P = .016) and OS (P = .003) of stage IV patients in multivariate analysis. Using markers of the epithelial-mesenchymal transition, single CTCs were divided into three phenotypes including epithelial CTCs, biphenotypic epithelial/mesenchymal CTCs, and mesenchymal CTCs. For CTM, CK?/Vimentin+/CD45? and CK+/Vimentin+/CD45? phenotypes were observed, but the CK+/Vimentin?/CD45? CTM phenotype was not. CA125 was detected in gastric cancer cell lines BGC823 and MGC803. CONCLUSIONS: In stage IV patients, CTM positivity was correlated with serum CA125 level. CTM were an independent predictor of shorter PFS and OS in stage IV patients. Thus, CTM detection may be a useful tool to predict prognosis in stage IV patients.     

Integrated Proteomics Identified Up-Regulated Focal Adhesion-Mediated Proteins in Human Squamous Cell Carcinoma in an Orthotopic Murine Model

Understanding the molecular mechanisms of oral carcinogenesis will yield important advances in diagnostics, prognostics, effective treatment, and outcome of oral cancer. Hence, in this study we have investigated the proteomic and peptidomic profiles by combining an orthotopic murine model of oral squamous cell carcinoma (OSCC), mass spectrometry-based proteomics and biological network analysis. Our results indicated the up-regulation of proteins involved in actin cytoskeleton organization and cell-cell junction assembly events and their expression was validated in human OSCC tissues. In addition, the functional relevance of talin-1 in OSCC adhesion, migration and invasion was demonstrated. Taken together, this study identified specific processes deregulated in oral cancer and provided novel refined OSCC-targeting molecules.     

A Dual Tracer 18F-FCH/18F-FDG PET Imaging of an Orthotopic Brain Tumor Xenograft Model

Early diagnosis of low grade glioma has been a challenge to clinicians. Positron Emission Tomography (PET) using ¹⁸F-FDG as a radio-tracer has limited utility in this area because of the high background in normal brain tissue. Other radiotracers such as ¹⁸F-Fluorocholine (¹⁸F-FCH) could provide better contrast between tumor and normal brain tissue but with high incidence of false positives. In this study, the potential application of a dual tracer ¹⁸F-FCH/¹⁸F-FDG-PET is investigated in order to improve the sensitivity of PET imaging for low grade glioma diagnosis based on a mouse orthotopic xenograft model. BALB/c nude mice with and without orthotopic glioma xenografts from U87 MG-luc2 glioma cell line are used for the study. The animals are subjected to ¹⁸F-FCH and ¹⁸F-FDG PET imaging, and images acquired from two separate scans are superimposed for analysis. The ¹⁸F-FCH counts are subtracted from the merged images to identify the tumor. Micro-CT, bioluminescence imaging (BLI), histology and measurement of the tumor diameter are also conducted for comparison. Results show that there is a significant contrast in ¹⁸F-FCH uptake between tumor and normal brain tissue (2.65 ± 0.98), but with a high false positive rate of 28.6%. The difficulty of identifying the tumor by ¹⁸F-FDG only is also proved in this study. All the tumors can be detected based on the dual tracer technique of ¹⁸F-FCH/ ¹⁸F-FDG-PET imaging in this study, while the false-positive caused by ¹⁸F-FCH can be eliminated. Dual tracer ¹⁸F-FCH/¹⁸F-FDG PET imaging has the potential to improve the visualization of low grade glioma. ¹⁸F-FCH delineates tumor areas and the tumor can be identified by subtracting the ¹⁸F-FCH counts. The sensitivity was over 95%. Further studies are required to evaluate the possibility of applying this technique in clinical trials.     

综述——基于纳米材料的生物检测与医学诊断技术：循环肿瘤细胞富集和检测的纳米技术

循环肿瘤细胞(CTC)是肿瘤转移过程中在血液循环系统中存活的肿瘤细胞,该细胞的生成被认为是肿瘤发生转移的必要前提．CTC的存在与否及数量多少是肿瘤预后判断、疗效监控和肿瘤转移评估的一个重要检测指标．近年来,纳米材料、纳米结构表面以及可操控微量液体的微流控技术广泛应用于CTC的富集和检测,本文对CTC富集、检测纳米技术的最新进展进行综述,希望能够为肿瘤的诊断和治疗提供帮助．     

Detection of Mouse Mammary Tumor Virus RNA in BALB/c Tumor Cell Lines of Nonviral Etiologies

A complementary DNA (cDNA) probe to mouse mammary tumor virus (MMTV) RNA was synthesized using calf thymus DNA oligonucleotides as a random primer. This probe was then used to study the expression of MMTV RNA in cell lines from BALB/c tumors induced in vivo either spontaneously or in response to viral, chemical, or hormonal stimuli. The cDNA had a length of approximately 400 to 500 nucleotides and specifically hybridized to MMTV RNA and BALB/c lactating mammary gland RNA, but not to Moloney leukemia virus RNA. Calf thymus DNA-primed cDNA could protect 50% of iodinated MMTV RNA from S1 nuclease digestion at cDNA-RNA ratios of 1:1 and 90% of labeled viral RNA at ratios of 10:1. Thermal denaturation of MMTV RNA-cDNA hybrids yielded a T(m) of 88.5 degrees C, indicative of a well-base-paired duplex. Screening of mouse mammary tumor cells for MMTV sequences revealed that three out of five lines of BALB/c origin had undetectable levels of viral RNA (相似文献