Acarbose lipids

Whereas sc xenograft tumors have been used extensively in the study of cell biology (17) and chemotherapy (18), their anatomical localization bears little relation to the natural acarbose lipids history of human ovarian cancer. Intraperitoneal Xenografts For certain experiments, e. , pharmacokinetic distribution studies of an antitumor drug, the use of an ovarian xenograft in a site other than the ovary or the peritoneal cavity is of debatable value. established a human clearcell carcinoma of the ovary ip in an immunomodulated hamster (19). However, the ip model is now most commonly used in nude mice (2023). Cells are injected ip and mimic the dissemination process demonstrated by ascitic cell spread. This model is of particular interest for testing the role of therapies administered ip, e. , cytokines such as gammainterferon (24) and is currently being used to explore the acarbose lipids potential of gene therapy (2527). Implantation of Tumor Fragments Under the Capsule of the Ovary A technically more challenging, but more complete, model has recently been reported, which involves the implantation of tumor fragments under the capsule of the ovary (28). These fragments grow locally and then metastasize giving rise to a realistic pattern of metastases involving spread into the peritoneum, colon, and omentum and the production of ascites. A large animal model in cyclosporinimmunosuppressed sheep has also been developed (29). The above models can either be maintained in vivo or reestablished from cell cultures in each experiment. With the primary establishment of the tumor into the immunodeficient mouse either directly from a patient or from a cell line, there is often marked variation in growth rates of individual tumors in different mice even though all are derived from the same source. If these tumors purchase lisinopril cheap over the counter using mastercard are passaged through several animals, more reproducible growth rates are achieved. Not all cell lines and primary tumor fragments grow readily in immunosuppressed animals. Where difficulty is experienced in establishing xenografts from either cell lines or primary tumors, then use of the extracellular matrix component Matrigel may help (Chapter 21) (30). This appears to be particularly helpful in the initial establishment of the tumor, but unnecessary for subsequent passage. For most ovarian cancer xenografts, the nature of the immunodeficient host does not appear to be overly critical and both nude (Tcell dysfunctional) and SCID mice (T and Bcell dysfunctional) can be used. Summary In summary, the use of human tumor xenografts in immunodeficient animals as a model for human cancers is well established. Their value depends on the extent to which their characteristics reflect the properties of a particular cancer in the clinical situation. Intraperitoneal xenografts seem to be no more difficult to establish than sc xenografts, however, implantation of tumor fragments under the capsule of the ovary is associated with technical difficulties. In experiments where the end point is sacrifice of the animals and measurement of the tumors, ip models mimic the clinical situation more closely than sc xenografts. However, sc xenograft models are more suitable for continuous measurement of tumor parameters, eg dimensions acarbose lipids for growth curves, because this is not possible with ip xenografts. At present, the most complete model available involves implantation of tumor material into the ovary, however, ip xenografts or sc xenografts are often sufficient for experimental needs. Summary Many in vitro and in vivo models systems are currently available to investigate characteristics of ovarian cancer cells. The model of choice depends on the aspect of ovarian cancer under investigation. Tissueculture systems acarbose lipids are often sufficient for preliminary studies that involve drug screening and have been responsible for providing much of the information known about hormonal mechanisms, signal transduction, apoptosis, chemoresistance, and other molecular characteristics of this disease. It can, however, be necessary to use an in vivo model where cell cultures have failed to provide a comparable environment to an in vivo human tumor. Whole animal studies may also be required for more extensive metabolic, pharmacokinetic, and toxicological investigations. In summary, many ovarian cancer models are available, however, careful consideration is required before deciding which model is suitable for any one study. It is important to select the most appropriate model to answer the question being posed. the model is simple enough to allow extraction of the information required without complication from irrelevant external parameters, 2. the model is not so simple that it is so far removed from the natural tumor environment that the information obtained is irrelevant. Deciding on a suitable experimental model is therefore a balance between being simple enough to understand without to many irrelevant complications. This overview has described many of the models available to study ovarian cancer and has highlighted the advantages and disadvantages associated with each of these models. (1984) Cell Culture Methods for Molecular and Cell Biology