搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Purpose: The bone marrow microenvironment is considered a critical component in the dissemination and fate of cancer cells in the metastatic process. We explored the possible correlation between bone marrow mesenchymal stem cells (BM-MSC) and disseminated breast cancer-initiating cells (BCIC) in primary breast cancer patients. Experimental design: Bone marrow mononuclear cells (BM-MNC) were collected at the time of primary surgery in 12 breast cancer patients. BM-MNC was immunophenotyped and BCIC was defined as epithelial cells (CD326+CD45-) with a stem-like" phenotype (CD44+CD24low/-� View Publication

The B-cell receptor (BCR) transmits life and death signals throughout B-cell development,and altered BCR signaling may be required for survival of B-lymphoma cells. We used single-cell signaling profiles to compare follicular lymphoma (FL) B cells and nonmalignant host B cells within individual patient biopsies and identified BCR-mediated signaling events specific to lymphoma B cells. Expression of CD20,Bcl-2,and BCR light chain isotype (kappa or lambda) distinguished FL tumor B-cell and nontumor host B-cell subsets within FL patient biopsies. BCR-mediated signaling via phosphorylation of Btk,Syk,Erk1/2,and p38 occurred more rapidly in tumor B cells from FL samples than in infiltrating nontumor B cells,achieved greater levels of per-cell signaling,and sustained this level of signaling for hours longer than nontumor B cells. The timing and magnitude of BCR-mediated signaling in nontumor B cells within an FL sample instead resembled that observed in mature B cells from the peripheral blood of healthy subjects. BCR signaling pathways that are potentiated specifically in lymphoma cells should provide new targets for therapeutic attention. View Publication

Despite increasing knowledge regarding melanoma-initiating cells (MICs),questions persist regarding the number and phenotypic nature of cells with tumor-generating capability. Evidence for a phenotypically distinct human MIC has been found in NOD/SCID (non-obese diabetic/severe combined immunodeficiency) mice. However,a phenotypically distinct human MIC was not found in the NOD/SCIDIl2rg(-)/(-) (NSG) mouse model. The demonstration of a distinct population of human melanoma cells responsible for tumorigenesis and tumor cell self-renewal would provide an important target for new melanoma therapies. In this study,we show a 100-fold range in MIC frequency in human melanoma (1 in 18,000 to 1 in 1,851,000 cells) in the NOD/SCID mouse. In this model,human melanoma cells with high aldehyde dehydrogenase (ALDH) activity were enriched 16.8-fold in tumorigenic cells over unfractionated (UNF) cells,such that 1 in 21,000 cells was a MIC. In the NSG mouse,the ALDH expressing cell population was enriched 100-fold in tumorigenic cells over UNF cells,such that one in four cells was a MIC. Xenograft melanomas that developed from ALDH(+) cells displayed robust self-renewal,whereas those from ALDH(-) cells showed minimal self-renewal in vitro. Thus,ALDH(+) melanoma cells have enhanced tumorigenicity over ALDH(-) cells and superior self-renewal ability. View Publication

In the context of pancreatic cancer,metastasis remains the most critical determinant of resectability,and hence survival. The objective of this study was to determine whether Hedgehog (Hh) signaling plays a role in pancreatic cancer invasion and metastasis because this is likely to have profound clinical implications. In pancreatic cancer cell lines,Hh inhibition with cyclopamine resulted in down-regulation of snail and up-regulation of E-cadherin,consistent with inhibition of epithelial-to-mesenchymal transition,and was mirrored by a striking reduction of in vitro invasive capacity (P textless 0.0001). Conversely,Gli1 overexpression in immortalized human pancreatic ductal epithelial cells led to a markedly invasive phenotype (P textless 0.0001) and near total down-regulation of E-cadherin. In an orthotopic xenograft model,cyclopamine profoundly inhibited metastatic spread; only one of seven cyclopamine-treated mice developed pulmonary micrometastases versus seven of seven mice with multiple macrometastases in control animals. Combination of gemcitabine and cyclopamine completely abrogated metastases while also significantly reducing the size of primary" tumors. Gli1 levels were up-regulated in tissue samples of metastatic human pancreatic cancer samples compared with matched primary tumors. Aldehyde dehydrogenase (ALDH) overexpression is characteristic for both hematopoietic progenitors and leukemic stem cells; cyclopamine preferentially reduced "ALDH-high" cells by approximately 3-fold (P = 0.048). We confirm pharmacologic Hh pathway inhibition as a valid therapeutic strategy for pancreatic cancer and show for the first time its particular efficacy against metastatic spread. By targeting specific cellular subpopulations likely involved in tumor initiation at metastatic sites� View Publication

The anti-proliferative activities of all twenty-five targeted kinase inhibitor drugs that are in clinical use were measured in two large assay panels: (1) a panel of proliferation assays of forty-four human cancer cell lines from diverse tumour tissue origins; and (2) a panel of more than 300 kinase enzyme activity assays. This study provides a head-on comparison of all kinase inhibitor drugs in use (status Nov. 2013),and for six of these drugs,the first kinome profiling data in the public domain. Correlation of drug activities with cancer gene mutations revealed novel drug sensitivity markers,suggesting that cancers dependent on mutant CTNNB1 will respond to trametinib and other MEK inhibitors,and cancers dependent on SMAD4 to small molecule EGFR inhibitor drugs. Comparison of cellular targeting efficacies reveals the most targeted inhibitors for EGFR,ABL1 and BRAF(V600E)-driven cell growth,and demonstrates that the best targeted agents combine high biochemical potency with good selectivity. For ABL1 inhibitors,we computationally deduce optimized kinase profiles for use in a next generation of drugs. Our study shows the power of combining biochemical and cellular profiling data in the evaluation of kinase inhibitor drug action. View Publication

High aldehyde dehydrogenase (ALDH) activity has recently been used to identify tumorigenic cell fractions in many cancer types. Herein we hypothesized that a subpopulation of cells with cancer stem cells (CSCs) properties could be identified in established human osteosarcoma cell lines based on high ALDH activity. We previously showed that a subpopulation of cells with high ALDH activity were present in 4 selected human osteosarcoma cell lines,of which a significantly higher ALDH activity was present in the OS99-1 cell line that was originally derived from a highly aggressive primary human osteosarcoma. Using a xenograft model in which OS99-1 cells were grown in NOD/SCID mice,we identified a highly tumorigenic subpopulation of osteosarcoma cells based on their high ALDH activity. Cells with high ALDH activity (ALDH(br) cells) from the OS99-1 xenografts were much less frequent,averaging 3% of the entire tumor population,compared to those isolated directly from the OS99-1 cell line. ALDH(br) cells from the xenograft were enriched with greater tumorigenicity compared to their counterparts with low ALDH activity (ALDH(lo) cells),generating new tumors with as few as 100 cells in vivo. The highly tumorigenic ALDH(br) cells illustrated the stem cell characteristics of self-renewal,the ability to produce differentiated progeny and increased expression of stem cell marker genes OCT3/4A,Nanog and Sox-2. The isolation of osteosarcoma CSCs by their high ALDH activity may provide new insight into the study of osteosarcoma-initiating cells and may potentially have therapeutic implications for human osteosarcoma. View Publication

First developed for hematologic disorders,the concept of cancer stem cells (CSCs) was expanded to solid tumors,including colorectal cancer (CRC). The traditional model of colon carcinogenesis includes several steps that occur via mutational activation of oncogenes and inactivation of tumor suppressor genes. Intestinal epithelial cells exist for a shorter amount of time than that required to accumulate tumor-inducing genetic changes,so researchers have investigated the concept that CRC arises from the long-lived stem cells,rather than from the differentiated epithelial cells. Colon CSCs were originally identified through the expression of the CD133 glycoprotein using an antibody directed to its epitope AC133. It is not clear if CD133 is a marker of colon CSCs-other cell surface markers,such as epithelial-specific antigen,CD44,CD166,Musashi-1,CD29,CD24,leucine-rich repeat-containing G-protein-coupled receptor 5,and aldehyde dehydrogenase 1,have been proposed. In addition to initiating and sustaining tumor growth,CSCs are believed to mediate cancer relapse after chemotherapy. How can we identify and analyze colon CSCs and what agents are being designed to kill this chemotherapy-refractory population? View Publication

Reprogramming blood cells to induced pluripotent stem cells (iPSCs) provides a novel tool for modeling blood diseases in vitro. However,the well-known limitations of current reprogramming technologies include low efficiency,slow kinetics,and transgene integration and residual expression. In the present study,we have demonstrated that iPSCs free of transgene and vector sequences could be generated from human BM and CB mononuclear cells using non-integrating episomal vectors. The reprogramming described here is up to 100 times more efficient,occurs 1-3 weeks faster compared with the reprogramming of fibroblasts,and does not require isolation of progenitors or multiple rounds of transfection. Blood-derived iPSC lines lacked rearrangements of IGH and TCR,indicating that their origin is non-B- or non-T-lymphoid cells. When cocultured on OP9,blood-derived iPSCs could be differentiated back to the blood cells,albeit with lower efficiency compared to fibroblast-derived iPSCs. We also generated transgene-free iPSCs from the BM of a patient with chronic myeloid leukemia (CML). CML iPSCs showed a unique complex chromosomal translocation identified in marrow sample while displaying typical embryonic stem cell phenotype and pluripotent differentiation potential. This approach provides an opportunity to explore banked normal and diseased CB and BM samples without the limitations associated with virus-based methods. View Publication

The major goal of researchers and oncologists is to develop promising ground for novel therapeutic strategies to prevent recurrence or relapse of cancer. Recent evidences suggest that a subset of cells called cancer stem cells (CSCs) are present within the tumor mass which possess tumorigenic capacity and may be responsible for propagation,relapse,and metastatic dissemination. These cells have certain stem cell-like properties,e.g. quiescence,selfrenewal,asymmetric division,and multidrug resistance which allow them to drive tumor growth and evade conventional therapies. A number of markers and assays have been designed to isolate and characterize the CSC population from the bulk tumor. The objective now is to selectively target the CSCs in order to eliminate the tumor from root,overcoming the emergence of clones capable of evading traditional therapy. This approach may help in increasing the overall disease-free survival in some cancers. View Publication