Selective killing of cancer stem cells by a novel dual-targeting strategy

Chemo- and radio-resistance of cancer stem cells (CSCs) in solid tumors are the root causes of some cancer treatment failures in clinics. To eradicate tumors, in the present study we proposed a novel strategy against CSCs with a core-shell dual-targeting system, which consists of outer layers and inner parts. Anti-tumor therapeutic agents are loaded in the outer layer targeting cancer cells whereas antibody-drug conjugates (ADCs) with CSC targeting are encapsulated in the inner parts. The novel system we proposed can be concentrated in tumor tissue by the enhanced permeability and retention (EPR) effect. The drugs dispersed in the outer layer are supposed to kill the cancer cells, and then ADCs will be released gradually from the inner part at the tumor site which can target CSCs and help to eliminate cancer cells. In this regard, we may be able to kill the CSCs with these therapeutic drug combinations and improve the therapeutic effect of chemotherapy in cancer treatments.     

Three-dimensional spheroid model in tumor biology.

It is becoming more and more apparent that monolayer cultures of tumor cells cannot completely represent the characteristics of three-dimensional solid tumors. Consequently, the multicellular tumor spheroid model, which is of intermediate complexity between in vivo tumors and monolayer cultures, was developed. In this review, the major similarities between spheroids and solid tumors are discussed. After a brief survey of the different spheroid culturing techniques, the general morphological and growth characteristics of these systems are examined and compared to solid tumors. Finally, selected studies regarding the use of tumor spheroids to examine cell response to antineoplastic agents and radiation, cell death including both necrosis and apoptosis and cell adhesion in spheroids are reviewed.     

Automatic bladder segmentation on CBCT for multiple plan ART of bladder cancer using a patient-specific bladder model

In multiple plan adaptive radiotherapy (ART) strategies of bladder cancer, a library of plans corresponding to different bladder volumes is created based on images acquired in early treatment sessions. Subsequently, the plan for the smallest PTV safely covering the bladder on cone-beam CT (CBCT) is selected as the plan of the day. The aim of this study is to develop an automatic bladder segmentation approach suitable for CBCT scans and test its ability to select the appropriate plan from the library of plans for such an ART procedure. Twenty-three bladder cancer patients with a planning CT and on average 11.6 CBCT scans were included in our study. For each patient, all CBCT scans were matched to the planning CT on bony anatomy. Bladder contours were manually delineated for each planning CT (for model building) and CBCT (for model building and validation). The automatic segmentation method consisted of two steps. A patient-specific bladder deformation model was built from the training data set of each patient (the planning CT and the first five CBCT scans). Then, the model was applied to automatically segment bladders in the validation data of the same patient (the remaining CBCT scans). Principal component analysis (PCA) was applied to the training data to model patient-specific bladder deformation patterns. The number of PCA modes for each patient was chosen such that the bladder shapes in the training set could be represented by such number of PCA modes with less than 0.1?cm mean residual error. The automatic segmentation started from the bladder shape of a reference CBCT, which was adjusted by changing the weight of each PCA mode. As a result, the segmentation contour was deformed consistently with the training set to fit the bladder in the validation image. A cost function was defined by the absolute difference between the directional gradient field of reference CBCT sampled on the corresponding bladder contour and the directional gradient field of validation CBCT sampled on the segmentation contour candidate. The cost function measured the goodness of fit of the segmentation on the validation image and was minimized using a simplex optimizer. For each validation CBCT image, the segmentations were done five times using a different reference CBCT. The one with the lowest cost function was selected as the final bladder segmentation. Volume- and distance-based metrics and the accuracy of plan selection were evaluated to quantify the performance. Two to four PCA modes were needed to represent the bladder shape variation with less than 0.1?cm average residual error for the training data of each patient. The automatically segmented bladders had a 78.5% mean conformity index with the manual delineations. The mean SD of the local residual error over all patients was 0.24?cm. The agreement of plan selection between automatic and manual bladder segmentations was 77.5%. PCA is an efficient method to describe patient-specific bladder deformation. The statistical-shape-based segmentation approach is robust to handle the relatively poor CBCT image quality and allows for fast and reliable automatic segmentation of the bladder on CBCT for selecting the appropriate plan from a library of plans.     

Obesity influence on bladder inflammation and cancer: a cystitis model

Background: Recently, the role of subclinical inflammation in obesity has gained prominence. An association between obesity and chronic inflammation has been observed in several studies that show a relationship between increased morbidity and high Body Mass Index (BMI). This study aims to compare inflammatory pathways in obese (by high-fat diet) and non-obese mice after exposure to an intravesical carcinogen in a cystitis model. Methods: We divided 16 female, 7 week old mice into two groups: 1) CONTROL: standard diet, and 2) OBESE: high fat diet for 8 weeks. Both groups underwent a protocol for N-Nitroso-N-methylurea (MNU) pro-inflammatory bladder instillation. Bladder was analyzed by histopathology and western blotting for proteins of the inflammatory pathway (JNK, NFκB, c-JUN, IKK), and immunohistochemistry (proliferation and apoptosis). Results: While mice eating standard diet showed minimal histologic alteration in 4 of 5 (80%) bladder tissues, those eating a high fat diet showed moderate (60%) and intense (40%) chronic active inflammation with dysplasia foci, increased proliferation, apoptosis and inflammatory pathway activation with increased NFκB, and also IKKβ, JNK, and c-JUN phosphorylation in the urothelium. Conclusion: A high-fat diet causes increased urothelial proliferation, apoptosis, and NFκB expression with cystitis exacerbation and dysplasia. Together, these results suggest that obesity induced by a high-fat diet increases the inflammatory pathway in the bladder with possible pre-malignant alterations.     

多细胞球样体的制备及其在肿瘤治疗研究中的应用

多细胞球样体(MCS)模型具有与体内细胞相似的生理或病理特性,能够更好地模拟细胞在体内的生物学行为,被广泛应用于治疗效能检测中,包括放疗、化疗、免疫治疗、联合治疗等;基于MCS建立的共培养系统为研究同种或异种细胞间的关系提供了良好的平台。本文将对多细胞球样体的制备及应用尤其是近年的新进展做一简要综述。     

The treatment of bladder cancer in a mouse model by epigallocatechin-3-gallate-gold nanoparticles

(--)-Epigallocatechin-3-gallate (EGCG), an active ingredient in green tea, was known to effectively inhibit formation and development of tumors. However, excessive uptake of EGCG was also known to cause cytotoxicity to normal cells. In this study, EGCGs that were physically attached onto the surface of nanogold particles (pNG) was confirmed by scanning electron microscopy. The anticancer activity of the EGCG-adsorbed pNG was investigated in C3H/HeN mice subcutaneously implanted with MBT-2 murine bladder tumor cells. EGCG-pNG was confirmed to inhibit tumor cell growing by means of cell apoptosis. The mechanism that EGCG-pNG mediates tumor apoptosis was uncovered to activate the caspase cascade through the Bcl-family proteins in the mitochondrial pathway. Additionally, the mechanism that tumors were suppressed by injecting EGCG-pNG directly into the tumor site was determined to be through downregulation of VEGF, whereas that by oral administration of EGCG was through reversing immune suppression upon cancer progression. In this assessment, the prepared EGCG-pNG was confirmed to be more effective than free EGCG in inhibiting bladder tumor in model mice.     

Selective killing of Paneth cells by intravenous administration of dithizone in rats

Paneth cells are zinc-containing cells widely distributed in Lieberkühn's crypts of intestine in a variety of species. We found that rapid selective killing of Paneth cells took place after the intravenous (i.v.) injection of diphenylthiocarbazone (dithizone), a chelator forming a zinc dithizonate complex, in the rat. As soon as 5 min after the i.v. injection of dithizone, degeneration of Paneth cells occurred. At this stage, zinc dithizonate complexes were observed as purple-red granules in bright field microscopy. Thirty to 60 min later, Paneth cells were detached from the basement membrane and shed into the cryptic lumen. After 6 h, the cell debris in the crypts was no longer seen and the crypts once housing Paneth cells were now occupied by neighbouring crypt base columnar cells. Histochemically demonstrable zinc totally disappeared. After 12-24 h, however, definite Paneth cells began to resume. Histochemical staining for zinc was again positive at the apex of these cells. One week after dithizone administration, the number of Paneth cells increased twice as much as in uninjected control and histochemical staining for zinc was highly positive. After 2 weeks, Paneth cell hyperplasia subsided. X-ray microanalysis revealed that zinc was the most abundant metal in Paneth cells. We concluded that chelation of zinc and formation of zinc-dithizone complexes in Paneth cells' cytoplasm would be responsible for the selective degeneration observed after dithizone administration.     

Leading malignant cells initiate collective epithelial cell invasion in a three-dimensional heterotypic tumor spheroid model

Solid tumors consist of genetically and phenotypically diverse subpopulations of cancer cells with unique capacities for growth, differentiation, and invasion. While the molecular and microenvironmental bases for heterogeneity are increasingly appreciated, the outcomes of such intratumor heterogeneity, particularly in the context of tumor invasion and metastasis, remain poorly understood. To study heterotypic cell–cell interactions and elucidate the biological consequences of intratumor heterogeneity, we developed a tissue-engineered multicellular spheroid (MCS) co-culture model that recapitulates the cellular diversity and fully three-dimensional cell–cell and cell–matrix interactions that characterize human carcinomas. We found that “invasion-competent” malignant cells induced the collective invasion of otherwise “invasion-incompetent” epithelial cells, and that these two cell types consistently exhibited distinct leader and follower roles during invasion. Analysis of extracellular matrix (ECM) microarchitecture revealed that malignant cell invasion was accompanied by extensive ECM remodeling including matrix alignment and proteolytic track-making. Inhibition of cell contractility- and proteolysis-mediated matrix reorganization prevented leader-follower behavior and malignant cell-induced epithelial cell invasion. These results indicate that heterogeneous subpopulations within a tumor may possess specialized roles during tumor progression and suggest that complex interactions among the various subpopulations of cancer cells within a tumor may regulate critical aspects of tumor biology and affect clinical outcome.     

Endometrial stromal cells regulate epithelial cell growth in vitro: a new co-culture model

The regulation of epithelial cell function and morphogenesis by the paracrine effectors from the mesenchyme or stroma has been well established using in-vivo studies. A more complete understanding of these relationships has been delayed due, in part, to a lack of appropriate co-culture models. In this study, we describe a co-culture model which demonstrates that normal paracrine relationships can be reconstituted in vitro and that human endometrial stromal cells regulate both growth and differentiation of primary human endometrial epithelial cells. Interesting differences in the proliferation of stromal and epithelial cells were noted in response to the basement membrane extract, Matrigel((R)). Exposure of stromal cells to Matrigel((R)) enhanced the paracrine capacity of these cells in vitro. When epithelial cells were co-cultured in contact with stromal cells embedded in Matrigel((R)), epithelial cell growth was inhibited by 65-80% compared to controls. Stromal cells in contact with Matrigel((R)) also regulated epithelial cell differentiation, as shown by induction of glycodelin expression. These co-culture studies show great promise as a method to investigate the cellular interactions between endometrial stromal and epithelial cells and their environment and to understand the molecular basis for the regulation of normal growth and differentiation of cells within complex tissues such as the endometrium.     

Patient-recognition data-mining model for BCG-plus interferon immunotherapy bladder cancer treatment

Bladder cancer is the fifth most common malignant disease in the United States with an annual incidence of around 63,210 new cases and 13,180 deaths. The cost for providing care for patients with bladder cancer disease is high. Bladder cancer treatment options such as immunotherapy, chemotherapy, radiation therapy, transurethral resection, and cystectomy, are used with varying success rates. In this research, data from a nationwide bacillus Calmette-Gue rin (BCG) plus interferon-alpha (IFN-alpha) immunotherapy clinical trial was considered. Data mining algorithms were used to analyze the effectiveness of immunotherapy treatment and to understand the prominent parameters and their interactions. The extracted knowledge was used to build a patient recognition model for prediction of treatment outcomes. The data was analyzed to understand the impact of various parameters on the treatment outcome. A list of significant parameters such as cumulative tumor size, presence of residual disease, stages of prior bladder cancer, current state of bladder cancer, and the presence of current bladder cancer (T1) is provided. The decision-making approach outlined in the paper supplemented with additional knowledge bases will lead to a comprehensive analytical road map of the BCG/IFN-alpha immunotherapy treatment. It will provide individualized guidelines for each stage of the treatment as well as measure the success of the treatment.     

Evidence for a glycoprotein in reovirus

Using both in vivo and in vitro labeling procedures, the presence of carbohydrate has been demonstrated in purified reovirions. Upon polyacrylamide gel electrophoresis this carbohydrate migrates with the medium size class of reovirus polypeptides. This sugar moiety is probably a trimer or tetramer linked O-glycosidically to a serine or threonine residue of the μ₂ polypeptide and the sugar residue at the nonreducing terminus is N-acetyl neuraminic acid. Preliminary evidence for the presence of N-acetyl galactosamine and galactose was also obtained. A quantitative determination of the carbohydrate content suggested that only 10 to 20 of the 550 μ₂ polypeptides per virion were glycosylated.     

共培养条件下乳腺癌细胞对淋巴管内皮细胞增殖的影响

目的建立乳腺癌细胞和淋巴管内皮细胞共培养模型,探讨乳腺癌细胞在共培养条件下对淋巴管内皮细胞增殖的影响。方法培养并鉴定淋巴管内皮细胞;利用transwell小室建立乳腺癌细胞与淋巴管内皮细胞体外共培养模型;采用MTT法检测乳腺癌细胞对淋巴管内皮细胞增殖情况。结果VEGFR-3抗体对培养的细胞进行鉴定,为典型淋巴管内皮细胞;MTT法结果显示：在共培养24~72 h时,乳腺癌细胞能够促进共培养条件下淋巴管内皮细胞的增殖（P〈0.05）。结论成功建立乳腺癌细胞和淋巴管内皮细胞共培养模型,乳腺癌细胞能够促进共培养条件下淋巴管内皮细胞的增殖。     

22 week assessment of bladder acellular matrix as a bladder augmentation material in a porcine model

Previous studies on the reconstruction of porcine bladder using bladder acellular matrix allograft (BAMA) have indicated positive preliminary results with respect to graft shrinkage and cellular repopulation. The current study was conducted to investigate the feasibility of using BAMA in a similar model of bladder reconstruction out to longer time frames (22 weeks). At predetermined time points, the macroscopic, histological and mechanical properties of explanted native and BAMA tissues were evaluated and compared. Macroscopically, contracture of the BAMA was observed. The peripheral regions of the grafts experienced extensive cellular repopulation. Towards the centre however, all grafts were consistently devoid of organized smooth muscle bundles and a well-developed urothelium. An alteration in both the amount and organization of collagen was also observed within this region. Significant differences (p < 0.05) in the rupture strain and the elastic modulus of the BAMA compared to native bladder tissue appear to correlate with macroscopic graft contracture as well as the fibroproliferative tissue response of the matrix.     

Selective killing of B-cell hybridomas targeting proteinase 3, Wegener's autoantigen

Wegener's granulomatosis (WG) is a rare disease characterized by granulomatous lesions, small vessel vasculitis and the presence of anti-neutrophil cytoplasmic autoantibodies (C-ANCAs) in the sera of affected patients. Their main target antigen is proteinase 3 (PR3), a neutrophil and monocyte-derived neutral serine protease. Since the standard treatment of this severe autoimmune disease, with cyclophosphamide and corticosteroids, is associated with potential side-effects, the development of a more specific immunotherapeutic agent is warranted. The key role of ANCA in the pathogenesis of vasculitis and the effectiveness of anti-CD20 antibodies in patients with refractory WG points towards the importance of B cells in WG. We thus evaluated a new approach to selectively eliminate PR3-specific autoreactive B cells by targeting the B-cell receptor. For this purpose we used a bifunctional recombinant fusion protein consisting of the antigen PR3 and a toxin. The cytotoxic component of this novel fusion protein was the ribonuclease angiogenin, a human toxin with low immunogenicity. The toxin was stabilized by exchanging the catalytically relevant histidine in position 44 with glutamine to eliminate the autoproteolytic activity. PR3H44Q was fused either to the N terminus or to the C terminus of angiogenin. The recombinant proteins were expressed in 293T cells. Binding assays demonstrated the appropriate size and recognition by anti-PR3 antibodies. Using TUNEL technology, we demonstrated that these autoantigen toxins kill proteinase 3-specific B-cell hybridomas selectively by inducing apoptosis. The data indicate that autoantigen-toxins are promising tools in the treatment or co-treatment of autoimmune diseases in which the antigen is known.     

Establishment and validation of an in vitro co-culture model to study the interactions between bone and prostate cancer cells

Bone is the preferred site for prostate cancer (PCa) metastases. Once the tumor has established itself within the bone there is virtually no cure. To better understand the interactions between the PCa cells and bone environment in the metastatic process new model systems are needed. We have established a two-compartment in vitro co-culturing model that can be used to follow the trans-activation of bone and/or tumor cells. The model was validated using two PCa tumor cell lines (PC-3; lytic and LNCaP; mixed/osteoblastic) and one osteolytic inducing factor, 1,25-dihydroxyvitamin D₃ (D3). Results were in accordance with the expected bone phenotypes; PC-3 cells and D3 gave osteolytic gene expression profiles in calvariae, with up-regulation of genes needed for osteoclast differentiation, activation and function; Rankl, CathK, Trap and MMP-9, and down-regulation of genes associated with osteoblast differentiation and bone mineralization; Alp, Ocl and Dkk-1. LNCaP cells activated genes in the calvarial bones associated with osteoblast differentiation and mineralization, with marginal effects on osteolytic genes. The results were strengthened by similar changes in protein expression for a selection of the analyzed genes. Furthermore, the osteolytic gene expression profiles in calvarial bones co-cultured with PC-3 cells or with D3 were correlated with the actual ongoing resorptive process, as assessed by the release of collagen fragments from the calvariae. Our results show that the model can be used to follow tumor-induced bone remodeling, and by measuring changes in gene expression in the tumor cells we can also study how they respond to the bone microenvironment.     

Role of adhesion molecules in lymphokine-activated killer cell killing of bladder cancer cells: further evidence for a third ligand for leucocyte function-associated antigen-1.

The lysis of eight human bladder cancer cell lines by lymphokine-activated killer cells (LAK) was found to be partially dependent upon the expression by the target cell of either intercellular adhesion molecule-1 (ICAM-1) or intercellular adhesion molecule-2 (ICAM-2). Using adhesion blockade studies these molecules were found to contribute towards sensitivity to lysis. Tumour lines of low grade (G1) did not constitutively express ICAM-1, but were found to express ICAM-2. High grade cells (G2, G3), however, only constitutively expressed ICAM-1 on their cell surface. Interferon-gamma (IFN-gamma) induced and augmented the expression of ICAM-1 by all except one of the cell lines (UMUC3) in a dose- and time-dependent manner. This was accompanied by an increased susceptibility to lymphokine-activated killer mediated cytolysis. Anti-ICAM-1 antibodies partially inhibited the increase in cell lysis due to IFN-gamma. However, this inhibition was not complete. When effector cells were treated with antibodies to leucocyte function-associated antigen-1 (LFA-1) the inhibition of lysis was greater and ranged from 72 to 96% with a mean of 87% inhibition. These results suggest that the increased sensitivity of IFN-gamma-treated bladder cancer cell lines to LAK cells is partially attributable to the induction of ICAM-1. However, blocking of ICAM-1 with antibodies could only partially inhibit the increased LFA-1-dependent lysis. This supports recent evidence for the existence of an additional ligand for LFA-1, other than ICAM-1 and ICAM-2.     

A reovirus challenge model applicable in commercial broilers after live vaccination

The efficacy of live reovirus vaccines may be determined by challenge via the foot pad route 3 to 4 weeks after vaccination. Swelling and discoloration in the foot pad and shank are scored for a period of 14 days. The major disadvantages of this challenge model are the subjective judgement of gross foot pad and/or shank lesions, that it is very difficult to induce lesions in broilers, and that it causes animal suffering. Other reovirus challenge models are based on reisolation of the virus from different tissues or on scoring microscopic lesions in the tendons. Some disadvantages of these models are that they either cannot be used after vaccination with live reovirus because they cannot discriminate between vaccine and challenge virus or that the microscopic lesions scored need not necessarily be related to the challenge virus but may have been induced by other factors. Therefore, we have attempted to develop a reovirus challenge model that was an improvement on the existing ones, using isolation of reovirus from different organs followed by specific detection of the challenge virus with a monoclonal antibody that can discriminate between challenge and vaccine virus. The reovirus challenge model was examined in specific pathogen free (SPF) White Leghorn chickens and commercial broilers. In vivo studies were conducted to examine the efficacy of an attenuated reovirus vaccine in SPF White Leghorn chickens and commercial broilers with maternal immunity against reovirus. No challenge virus could be detected in any of the organs of the vaccinated chickens 3 and 10 days after challenge. In contrast, challenge virus could be isolated from the unvaccinated control group. At an increased challenge dose all unvaccinated challenge control birds were positive, while the vaccinated chickens were protected. It was shown that 1-day-old vaccination in the presence of maternal immunity was effective. It seemed that protection induced in broilers by the attenuated reovirus vaccine may not have been entirely humoral because in protected birds no antibodies against reovirus were detected by enzyme-linked immunosorbent at the time of challenge. Protection in these birds might therefore have been induced by cellular immunity.     

Changes in bladder innervation in a mouse model of Alzheimer's disease

AimThe aims of this study were to compare the structure of bladders from a transgenic mouse model of Alzheimer's disease with age matched control animals and to explore the idea that any structural differences might be related to functional bladder changes associated with the condition.Materials and methodsTwo groups of mice were used. Transgenic animals in which the murine Amyloid Precursor Protein (APP) gene has been partly replaced by the human APP including both the Swedish and London mutations and that overexpress a mutant of the human Presenilin 1 gene (PS1M146L) driven by the PDGF promoter. The transgenic mice (App^SL/PS1^M146L) aged 24 ± 3 months were used. The second group was an age matched control group of C57 black mice. The bladders from each group were isolated, fixed in 4% paraformaldehyde and prepared for immunohistochemistry. Antibodies to the vesicular acetylcholine transporter (VAChT) and neuronal nitric oxide synthase (nNOS) were used to identify neural structures.ResultsCholinergic nerves (VAChT⁺) were observed in the inner and outer muscle bundles of App^SL/PS1^M146L and control mice. No major differences were noted in the distribution of these fibres. In contrast, there was a distinct difference in the innervation of the sub-urothelial layer. In App1^SL/PS1^M146L mice there were numerous VAChT and nNOS positive fibres in sharp contrast to the paucity of similar nerves in control animals. VAChT and nNOS did not appear to co-localise in the same nerve fibres within the lamina propria. Pairs of nerve fibres, nNOS⁺ and VAChT⁺, were observed to be intertwined and run in close proximity. A particularly unusual feature of the App^SL/PS1^M146L mouse bladder was the presence of neurones within the bladder wall. These nerve cell bodies were seen in all App^SL/PS1^M146L mouse bladders. The neurones could be found singly or in small ganglion like groups of cells and were located in all layers of the bladder wall (sub-urothelium, in the lamina propria adjacent to the inner muscle and within the inner muscle and outer muscle layers). No nerve cells or small ganglia were noted in any of the control bladders studied.ConclusionsThere are structural differences in the bladders of App^SL/PS1^M146L mice compared to control animals. These differences are associated with sub-urothelial nerves which, because of their location, are likely to be sensory fibres. This may lead to a changed sensory processing from the App^SL/PS1^M146L bladders. The physiological role of the intra-mural neurones and ganglia is not known. It is speculated that they may be associated with peripheral motor/sensory mechanisms linked to the generation and modulation of sensation.