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

The origins of the epithelial cells participating in the development,tissue homeostasis,and cancer of the human breast are poorly understood. However,emerging evidence suggests a role for adult tissue-specific stem cells in these processes. In a hierarchical manner,these generate the two main mammary cell lineages,producing an increasing number of cells with distinct properties. Understanding the biological characteristics of human breast stem cells and their progeny is crucial in attempts to compare the features of normal stem cells and cancer precursor cells and distinguish these from nonprecursor cells and cells from the bulk of a tumor. A historical overview of research on human breast stem cells in primary tissue and in culture reveals the progress that has been made in this area,whereas a focus on the cell-of-origin and reprogramming that occurs during neoplastic conversion provides insight into the enigmatic way in which human breast cancers are skewed toward the luminal epithelial lineage. View Publication

The vast majority of cancer-related death is due to the metastatic spread of the primary tumour. Circulating tumour cells (CTC) are essential for establishing metastasis and their detection has long been considered as a possible tool to assess the aggressiveness of a given tumour and its potential of subsequent growth at distant organs. Conventional markers are not reliable in detecting occult metastasis and,for example,fail to identify approximately 40% of cancer patients in need of more aggressive or better adjusted therapies. Recent studies in metastatic breast cancer have shown that CTC detection can be used as a marker for overall survival and assessment of the therapeutic response. The benefits of CTC detection in early breast cancer and other solid tumours need further validation. Moreover,optimal CTC detection techniques are the subject of controversy as several lack reproducibility,sensitivity and/or specificity. Recent technical advances allow CTC detection and characterization at the single-cell level in the blood or in the bone marrow. Their reproducibility propels the use of CTC in cancer staging and real-time monitoring of systemic anticancer therapies in several large clinical trials. CTC assays are being integrated in large clinical trials to establish their potential in the management of cancer patients and improve our understanding of metastasis biology. This review will focus on the techniques currently used,the technical advancements made,the limitations of CTC detection and future perspectives in this field. View Publication

Acute myelogenous leukemia 1 (AML1; runt-related transcription factor 1 [Runx1]) is a member of Runx transcription factors and is essential for definitive hematopoiesis. Although AML1 possesses several subdomains of defined biochemical functions,the physiologic relevance of each subdomain to hematopoietic development has been poorly understood. Recently,the consequence of carboxy-terminal truncation in AML1 was analyzed by the hematopoietic rescue assay of AML1-deficient mouse embryonic stem cells using the gene knock-in approach. Nonetheless,a role for specific internal domains,as well as for mutations found in a human disease,of AML1 remains to be elucidated. In this study,we established an experimental system to efficiently evaluate the hematopoietic potential of AML1 using a coculture system of the murine embryonic para-aortic splanchnopleural (P-Sp) region with a stromal cell line,OP9. In this system,the hematopoietic defect of AML1-deficient P-Sp can be rescued by expressing AML1 with retroviral infection. By analysis of AML1 mutants,we demonstrated that the hematopoietic potential of AML1 was closely related to its transcriptional activity. Furthermore,we showed that other Runx transcription factors,Runx2/AML3 or Runx3/AML2,could rescue the hematopoietic defect of AML1-deficient P-Sp. Thus,this experimental system will become a valuable tool to analyze the physiologic function and domain contribution of Runx proteins in hematopoiesis. View Publication

PURPOSE: The molecular signal components essential to paclitaxel-dependent apoptosis in breast cancers are potential targets for combined therapy. However,the signal mechanisms underlying paclitaxel action still need to be better defined. EXPERIMENTAL DESIGN: In a breast cancer cell line,pharmacological agents and transient transfection with dominant interfering and constitutive active mutants were used to identify the signal transduction module involved in the regulation of paclitaxel-induced apoptosis and to evaluate its potential as a therapeutic target. RESULTS: In MDA-MB-435 cells,paclitaxel treatment stimulated the activity of both protein kinase A and p38,and inhibited the activity of the Na(+)/H(+) exchanger isoform 1 (NHE1) with similar IC(50) concentrations as for its activation of apoptosis. Activation and inhibition experiments demonstrated that protein kinase A and p38 participate sequentially upstream of the NHE1 in regulating the paclitaxel-induced apoptotic pathway. Importantly,concurrent specific inhibition of the NHE1 with paclitaxel treatment resulted in a synergistic induction of apoptosis and a reduction in the paclitaxel IC(50) for apoptosis. This sensitization of paclitaxel apoptotic action by specific inhibition of NHE1 was verified in breast cancer cell lines with different paclitaxel sensitivity. CONCLUSIONS: We have,for the first time,identified NHE1 as an essential component of paclitaxel-induced apoptosis in breast cancer cells and,importantly,identified that simultaneous inhibition of the NHE1 results in a synergistic potentiation of low-dose paclitaxel apoptotic action. As specific NHE1 inhibitors have finished Phase II/Phase III clinical trials for myocardial protection,there is the possibility for a rapid biological translation of this novel therapeutic strategy to a clinical setting. View Publication

Despite many years of intensive effort,there is surprisingly little consensus on the most suitable markers with which to locate and isolate stem cells from adult tissues. By comparison,the study of cancer stem cells is still in its infancy; so,unsurprisingly,there is great uncertainty as to the identity of these cells. Stem cell markers can be broadly categorized into molecular determinants of self-renewal,clonogenicity,multipotentiality,adherence to the niche,and longevity. This review assesses the utility of recognizing cancer stem cells by virtue of high expression of aldehyde dehydrogenases (ALDHs),probably significant determinants of cell survival through their ability to detoxify many potentially cytotoxic molecules,and contributing to drug resistance. Antibodies are available against the ALDH enzyme family,but the vast majority of studies have used cell sorting techniques to enrich for cells expressing these enzymes. Live cells expressing high ALDH activity are usually identified by the ALDEFLUOR kit and sorted by fluorescence activated cell sorting (FACS). For many human tumours,but notably breast cancer,cell selection based upon ALDH activity appears to be a useful marker for enriching for cells with tumour-initiating activity (presumed cancer stem cells) in immunodeficient mice,and indeed the frequency of so-called ALDH(bri) cells in many tumours can be an independent prognostic indicator. View Publication

Clinical trials are currently used to test therapeutic efficacies for lung cancer,infections and diseases. Animal models are also used as surrogates for human disease. Both approaches are expensive and time-consuming. The utility of human biospecimens as models is limited by specialized tissue processing methods that preserve subclasses of analytes (e.g. RNA,protein,morphology) at the expense of others. We present a rapid and reproducible method for the cryopreservation of viable lung tissue from patients undergoing lobectomy or transplant. This method involves the pseudo-diaphragmatic expansion of pieces of fresh lung tissue with cryoprotectant formulation (pseudo-diaphragmatic expansion-cryoprotectant perfusion or PDX-CP) followed by controlled-rate freezing in cryovials. Expansion-perfusion rates,volumes and cryoprotectant formulation were optimized to maintain tissue architecture,decrease crystal formation and increase long-term cell viability. Rates of expansion of 4 cc/min or less and volumes ranging from 0.8-1.2 × tissue volume were well-tolerated by lung tissue obtained from patients with chronic obstructive pulmonary disease or idiopathic pulmonary fibrosis,showing minimal differences compared to standard histopathology. Morphology was greatly improved by the PDX-CP procedure compared to simple fixation. Fresh versus post-thawed lung tissue showed minimal differences in histology,RNA integrity numbers and post-translational modified protein integrity (2-dimensional differential gel electrophoresis). It was possible to derive numerous cell types,including alveolar epithelial cells,fibroblasts and stem cells,from the tissue for at least three months after cryopreservation. This new method should provide a uniform,cost-effective approach to the banking of biospecimens,with versatility to be amenable to any post-acquisition process applicable to fresh tissue samples. View Publication

Recent population studies provide clues that the use of metformin may be associated with reduced incidence and improved prognosis of certain cancers. This drug is widely used in the treatment of type 2 diabetes,where it is often referred to as an insulin sensitizer" because it not only lowers blood glucose but also reduces the hyperinsulinemia associated with insulin resistance. As insulin and insulin-like growth factors stimulate proliferation of many normal and transformed cell types� View Publication

Aldehyde dehydrogenases (ALDHs) belong to a superfamily of NAD(P)+-dependent enzymes,which catalyze the oxidation of endogenous and exogenous aldehydes to their corresponding acids. Increased expression and/or activity of ALDHs,particularly ALDH1A1,have been reported to occur in human cancers. It is proposed that the metabolic function of ALDH1A1 confers the stemness" properties to normal and cancer stem cells. Nevertheless� View Publication