Tumor Stem Cell Assay

About: Tumor Stem Cell Assay is a research topic. Over the lifetime, 347 publications have been published within this topic receiving 22572 citations.

Cancer stem cells--perspectives on current status and future directions: AACR Workshop on cancer stem cells.

Abstract: A workshop was convened by the AACR to discuss the rapidly emerging cancer stem cell model for tumor development and progression. The meeting participants were charged with evaluating data suggesting that cancers develop from a small subset of cells with self-renewal properties analogous to organ

Phenotypic characterization of human colorectal cancer stem cells

Abstract: Recent observations indicate that, in several types of human cancer, only a phenotypic subset of cancer cells within each tumor is capable of initiating tumor growth. This functional subset of cancer cells is operationally defined as the “cancer stem cell” (CSC) subset. Here we developed a CSC model for the study of human colorectal cancer (CRC). Solid CRC tissues, either primary tissues collected from surgical specimens or xenografts established in nonobese diabetic/severe combined immunodeficient (NOD/SCID) mice, were disaggregated into single-cell suspensions and analyzed by flow cytometry. Surface markers that displayed intratumor heterogeneous expression among epithelial cancer cells were selected for cell sorting and tumorigenicity experiments. Individual phenotypic cancer cell subsets were purified, and their tumor-initiating properties were investigated by injection in NOD/SCID mice. Our observations indicate that, in six of six human CRC tested, the ability to engraft in vivo in immunodeficient mice was restricted to a minority subpopulation of epithelial cell adhesion molecule (EpCAM)high/CD44+ epithelial cells. Tumors originated from EpCAMhigh/CD44+ cells maintained a differentiated phenotype and reproduced the full morphologic and phenotypic heterogeneity of their parental lesions. Analysis of the surface molecule repertoire of EpCAMhigh/CD44+ cells led to the identification of CD166 as an additional differentially expressed marker, useful for CSC isolation in three of three CRC tested. These results validate the stem cell working model in human CRC and provide a highly robust surface marker profile for CRC stem cell isolation.

Primary bioassay of human tumor stem cells

Abstract: A bioassay method for supporting human tumor stem cell colony growth is disclosed. The method is suitable for culture of a variety of neoplasms of differing histopathology. Tumor stem cell colonies arising from different types of cancer have differing growth characteristics and colony morphology. The present bioassay may be employed in clinical studies of the effects of anticancer drugs or irradiation on human tumor stem cells.

Selective events in the metastatic process defined by analysis of the sequential dissemination of subpopulations of a mouse mammary tumor.

Abstract: To identify selective steps in metastasis, those that eliminate nonmetastatic tumor cells more efficiently than metastatic cells, we have evaluated the sequential dissemination of tumor cells from a mammary fatpad, using both metastatic (4T1 and 66cl4) and nonmetastatic (67NR, 168FARN, and 4TO7) subpopulations of a single mouse mammary tumor. Each of these variant subpopulations is resistant to one or more selective drugs so they could be quantitatively identified by colony formation in selective media. We found that the 2 metastatic cell lines metastasized by different routes and that the nonmetastatic tumor cell lines failed at different points in dissemination. Line 67NR did not leave the primary site; clonogenic tumor cells were not detected in the nodes, blood, or lungs during the experiment (7 weeks). Tumor line 168FARN disseminated from the primary tumor because clonogenic cells were cultured from the draining lymph nodes throughout the experiment. However, dissemination essentially stopped in the node as cells were rarely isolated from blood, lungs, or lives. Whether 168FARN cells failed to reach these tissues or were killed very rapidly after traversing the lymph node is unknown. Line 4TO7 cells disseminated via the blood and were consistently recovered from lungs by day 19 but failed to proliferate. This panel of 5 subpopulations thus identifies different points of selective failure in tumor cell dissemination and should be valuable in the assessment of antimetastatic therapies.

Lineage Tracing Reveals Lgr5+ Stem Cell Activity in Mouse Intestinal Adenomas

Abstract: The concept that tumors are maintained by dedicated stem cells, the so-called cancer stem cell hypothesis, has attracted great interest but remains controversial. Studying mouse models, we provide direct, functional evidence for the presence of stem cell activity within primary intestinal adenomas, a precursor to intestinal cancer. By "lineage retracing" using the multicolor Cre-reporter R26R-Confetti, we demonstrate that the crypt stem cell marker Lgr5 (leucine-rich repeat-containing heterotrimeric guanine nucleotide-binding protein-coupled receptor 5) also marks a subpopulation of adenoma cells that fuel the growth of established intestinal adenomas. These Lgr5(+) cells, which represent about 5 to 10% of the cells in the adenomas, generate additional Lgr5(+) cells as well as all other adenoma cell types. The Lgr5(+) cells are intermingled with Paneth cells near the adenoma base, a pattern reminiscent of the architecture of the normal crypt niche.