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Background: There is compelling evidence showing that cellular cardiomyoplasty can improve cardiac function. Considering the potential benefit of using noncultured muscle cells (little time, lower cost, reduced risk of contamination), we investigated the feasibility of grafting cells obtained directly after enzymatic dissociation of skeletal muscle biopsies into ovine myocardium. We hypothesized that those noncultured muscle cells would engraft massively., Methods and Results: Autologous, intramyocardial skeletal muscle cell implantation was performed in 8 sheep. A skeletal muscle biopsy sample ( approximately 10 g) was explanted from each animal. The sheep were left to recover for approximately 3 hours and reanesthetized when the cells were ready for implantation. A left fifth intercostal thoracotomy was performed, and 10 epicardial injections of the muscle preparation (between 10 and 20 million cells) were carried out. All sheep were euthanized 3 weeks after myocardial implantation. Immunohistochemistry was performed with monoclonal antibodies to a fast skeletal isoform of myosin heavy chain. Skeletal myosin heavy-chain expression was detected in all slides at 3 weeks after implantation in 8 of 8 animals, confirming engraftment of skeletal muscle cells. Massive areas of engraftment (from 2 to 9 mm in diameter) or discrete loci were noted within the myocardial wall., Conclusions: Our results indicate that noncultured skeletal muscle cells can successfully and massively engraft in ovine myocardium. Thus, avoiding the cell culture expansion phase is feasible and could become a promising option for cellular cardiomyoplasty.

Overexpression of the OZF gene has previously been demonstrated in the majority of pancreatic cancers. However, because the stages of tumour progression in this disease are poorly defined, no conclusion could be drawn concerning the relationship between OZF overexpression and the course of tumour progression. In contrast, initiation and progression steps are well defined in colorectal cancer. Most colon cancers are believed to arise from polypoid adenomas as a result of the gradual accumulation of genetic alterations, allowing the study of genetic events in the early stages of neoplasia. Accordingly, we wanted to assess the frequency of OZF overexpression in this tumour type and the relationship between overexpression and disease stage. Twenty-five colon carcinoma specimens from different sites and at various stages were analysed by immunoblotting using a highly specific mouse monoclonal antibody. Each sample was compared with adjacent normal colonic mucosa. Complementary immunohistochemical analysis was also carried out on a commercially available tissue array to identify cells expressing OZF. Of the 25 tumours analysed by immunoblotting, 20 expressed higher levels of OZF protein than their adjacent normal mucosa. Immunohistochemistry revealed OZF expression in tumour cells of 56/59 carcinomas and occasionally in infiltrating lymphocytes but at lower levels. Little or no staining was observed in cells taken from normal or inflammatory colon specimens. In both immunoblot and immunohistochemistry experiments, no correlation was found between OZF expression and clinical parameters such as TNM classification, stage, localization and age. Immunostaining was observed in low-grade adenomas, indicating that OZF expression occurs very early in the course of tumour progression. OZF expression, infrequent or absent in normal colonic mucosa, is present in more than 80% of colorectal cancers. Dysregulation of the OZF gene is an early event that may be implicated in the genesis of colonic carcinoma and may therefore provide a potential therapeutic target., (Copyright 2003 John Wiley & Sons, Ltd.)

In order to assess the effect of in vitro models on the expression of key genes known to be implicated in the development or progression of cancer, we quantified by real-time quantitative PCR the expression of 28 key genes in three bladder cancer tissue specimens and in their derived cell lines, studied either as one-dimensional single cell suspensions, two-dimensional monolayers or three-dimensional spheroids. Global analysis of gene expression profiles showed that in vitro models had a dramatic impact upon gene expression. Remarkably, quantitative differences in gene expression of 2-63-fold were observed in 24 out of 28 genes among the cell models. In addition, we observed that the in vitro model which most closely mimicked in vivo mRNA phenotype varied with both the gene and the patient. These results provide evidence that mRNA expression databases based on cancer cell lines, which are studied to provide a rationale for selection of therapy on the basis of molecular characteristics of a patient's tumour, must be carefully interpreted., (Copyright 2002 Cancer Research UK)

To investigate the influence of tumor cell architecture on T-cell activation, we used an autologous human model based on 2 bladder tumor cell lines as targets for cytotoxic tumor-infiltrating lymphocytes (TILs). These tumor cell lines were grown in vitro as either standard 2-dimensional (2D) monolayers or 3-dimensional (3D) spheroids. T-cell activation was determined by measuring the production of three major cytokines (tumor necrosis factor, granulocyte/macrophage colony-stimulating factor and interferon-gamma), known to be secreted by most activated TILs. Changes in the architecture of target cells from 2D to 3D induced a dramatic decrease in their capacity for stimulating TILs. Interestingly, neither TIL infiltration nor MHC class I, B7.1 costimulatory or lymphocyte function-associated factor-3 adhesion molecule downregulation played a major role in this decrease. These findings demonstrate that tumor architecture has a major impact on T-cell activation and might be implicated in the escape of tumor cells from the immune system., (Copyright 2001 Wiley-Liss, Inc.)