Differential Staining Cytotoxicity assay: a review.
ABSTRACT Differential Staining Cytotoxicity (DiSC) assay is the prototype for a closely related family of assays based on the concept of total cell kill, or, in other words, cell death occurring in the entire population of tumor cells. It is probably the most versatile of the cell-death end points, in that it (1) can be applied to both solid and hematologic neoplasms, (2) can be applied to specimens in which it is not possible to obtain a pure population of highly enriched tumor cells, and (3) can be applied to a wide variety of drugs, ranging from traditional cytotoxic agents to biological response modifiers with activity mediated through tumor-infiltrating effector cells, to "targeted" kinase inhibitors, and to antivascular agents, such as bevacizumab and pazopanib. The basic principles of the assay are to culture three-dimensional fresh tumor cell clusters in anchorage-independent conditions. At the conclusion of the culture period, Fast Green dye is added to the microwells, the contents of which are then sedimented onto permanent Cytospin centrifuge slides and then counterstained with hematoxylin-eosin or Wright-Giemsa. "Living" cells stain with the cytologic stain in question and can be identified as either normal or neoplastic, based on standard morphologic criteria. "Dead" cells stain blue-green. Nonviable endothelial cells appear as strikingly hyperchromatic, blue-black, and often refractile objects, which may be readily distinguished from other types of dead cells. This assay has been biologically and clinically validated in a number of ways, as described in this chapter.
Full-textDOI: · Available from: Larry M Weisenthal, May 27, 2015
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ABSTRACT: The drug sensitivity of normal cells provides a baseline for determining the therapeutic index, and therefore the effectiveness, of cytotoxic drugs, yet little is known about the factors that affect normal cell chemosensitivity. Some parameters are known to have a profound effect on tumor cell sensitivity. The purpose of this study was to determine how cytotoxic drug sensitivity of hematopoietic cells isolated from cancer patients was affected by various parameters. These included previous chemotherapy (yes or no), sex, age, tumor type (leukemias or solid tumors), sample source (blood, bone marrow, serous effusions, or tumor biopsies) and predominant cell lineage (lymphoid, myeloid, macrophage, or mixed). Mononuclear cells isolated from blood, bone marrow, serous effusions, and tumor biopsies were incubated for four days with a median of 16 drugs. The differential staining cytotoxicity assay, an ex vivo apoptotic drug sensitivity test in which cell survival is determined morphologically, was used to assess normal hematopoietic and tumor cell response to cytotoxic drugs. One hundred forty-six specimens yielded hematopoietic cell chemosensitivity results with 3-36 drugs. Compared with tumor cells, there was far less interpatient variation in chemosensitivity of hematopoietic cells. Mean hematopoietic cell drug sensitivity showed little variation due to previous chemotherapy, sex, age, tumor type, and sample source or cell lineage. We therefore concluded that cytotoxic drug sensitivity of hematopoietic cells from a variety of sources could be used for assessment of therapeutic index. Drug therapeutic index results are a valuable tool in identifying novel cytotoxic agents and individually tailored chemotherapy regimens.Journal of Experimental Therapeutics and Oncology 01/2002; 2(1):53-63. DOI:10.1046/j.1359-4117.2002.01007.x
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ABSTRACT: Toxicity is a major deterrent to achieving substantial improvements in cancer management, since most anticancer drugs inadequately distinguish normal and neoplastic tissues. Improving the differential between beneficial and toxic effects of therapy--therapeutic index--is a major clinical objective, but therapeutic index for cytotoxic drugs is narrow. Fresh tumor and normal cells from 59 patients with acute myeloid leukemia, non-Hodgkin's lymphoma, ovarian cancer and cancers of unknown origin were tested for ex vivo drug sensitivity using apoptosis by morphology assays. Drugs tested included carboplatin, doxorubicin, vincristine, cytarabine, fludarabine, mafosfamide and etoposide. Therapeutic index was derived from the ratio of normal and tumor cell LC90s. Individual patient therapeutic index varied markedly for different drugs and drug therapeutic index varied from patient to patient ranging from extremely unfavourable (<0.001) through excellent (>1000) reflecting patient heterogeneity. Therapeutic index for each drug was consistent with clinical expectations. Significantly, there was no relationship between normal and tumor cell LC90s. We conclude that further laboratory and clinical evaluation is required but the derived ex vivo therapeutic index could enhance choice of chemotherapy by reducing toxicity and/or improving efficacy.Journal of Experimental Therapeutics and Oncology 08/2004; 4(2):145-54.
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ABSTRACT: To evaluate the safety and efficacy of cisplatin plus gemcitabine in persistent or recurrent platinum-resistant ovarian and primary peritoneal cancer. Eligible, consenting subjects with measurable disease and one prior platinum-based regimen, but no prior gemcitabine, were to receive intravenous cisplatin followed by gemcitabine on days 1 and 8 every 28 days. Between December 2000 and March 2003, 59 patients were enrolled from 24 institutions; two were ineligible. During the first stage of accrual, 27 subjects received cisplatin 30 mg/m2 and gemcitabine 750 mg/m2. In the second stage, gemcitabine was reduced to 600 mg/m2 because of hematologic toxicity at the higher dose. There were 4 complete and 5 partial responses for an overall response rate of 16% (9/57). Thirty-one women (54%) had stable disease. Median time to progression was 5.4 months. Overall survival was 14.9+ months. Grade 4 toxicities were hematologic, except one cutaneous reaction. Cisplatin plus gemcitabine, in the doses and schedule employed, has modest activity in this patient population.Gynecologic Oncology 12/2006; 103(2):446-50. DOI:10.1016/j.ygyno.2006.03.018 · 3.69 Impact Factor