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

Progressive bone marrow failure is a major cause of morbidity and mortality in human Fanconi Anemia patients. In an effort to develop a Fanconi Anemia murine model to study bone marrow failure,we found that Fancd2(-/-) mice have readily measurable hematopoietic defects. Fancd2 deficiency was associated with a significant decline in the size of the c-Kit(+)Sca-1(+)Lineage(-) (KSL) pool and reduced stem cell repopulation and spleen colony-forming capacity. Fancd2(-/-) KSL cells showed an abnormal cell cycle status and loss of quiescence. In addition,the supportive function of the marrow microenvironment was compromised in Fancd2(-/-) mice. Treatment with Sirt1-mimetic and the antioxidant drug,resveratrol,maintained Fancd2(-/-) KSL cells in quiescence,improved the marrow microenvironment,partially corrected the abnormal cell cycle status,and significantly improved the spleen colony-forming capacity of Fancd2(-/-) bone marrow cells. We conclude that Fancd2(-/-) mice have readily quantifiable hematopoietic defects,and that this model is well suited for pharmacologic screening studies. View Publication

The MEK1 and MEK2 inhibitor GSK1120212 is currently in phase II/III clinical development. To identify predictive biomarkers,sensitivity to GSK1120212 was profiled for 218 solid tumor cell lines and 81 hematologic malignancy cell lines. For solid tumors,RAF/RAS mutation was a strong predictor of sensitivity. Among RAF/RAS mutant lines,co-occurring PIK3CA/PTEN mutations conferred a cytostatic response instead of a cytotoxic response for colon cancer cells that have the biggest representation of the comutations. Among KRAS mutant cell lines,transcriptomics analysis showed that cell lines with an expression pattern suggestive of epithelial-to-mesenchymal transition were less sensitive to GSK1120212. In addition,a proportion of cell lines from certain tissue types not known to carry frequent RAF/RAS mutations also seemed to be sensitive to GSK1120212. Among these were breast cancer cell lines,with triple negative breast cancer cell lines being more sensitive than cell lines from other breast cancer subtypes. We identified a single gene DUSP6,whose expression was associated with sensitivity to GSK1120212 and lack of expression associated with resistance irrelevant of RAF/RAS status. Among hematologic cell lines,acute myeloid leukemia and chronic myeloid leukemia cell lines were particularly sensitive. Overall,this comprehensive predictive biomarker analysis identified additional efficacy biomarkers for GSK1120212 in RAF/RAS mutant solid tumors and expanded the indication for GSK1120212 to patients who could benefit from this therapy despite the RAF/RAS wild-type status of their tumors. View Publication

Throughout its history,chronic myeloid leukemia (CML) has set precedents for cancer research and therapy. These range from the identification of the first specific chromosomal abnormality associated with cancer to the development of imatinib as a specific,targeted therapy for the disease. The successful development of imatinib as a therapeutic agent for CML can be attributed directly to decades of scientific discoveries. These discoveries determined that the BCR-ABL tyrosine kinase is the critical pathogenetic event in CML and an ideal target for therapy. This was confirmed in clinical trials of imatinib,with imatinib significantly improving the long-term survival of patients with CML. Continuing in this tradition of scientific discoveries leading to improved therapies,the understanding of resistance to imatinib has rapidly led to strategies to circumvent resistance. Continued studies of hematologic malignancies will allow this paradigm of targeting molecular pathogenetic events to be applied to many additional hematologic cancers. View Publication

BACKGROUND: Mammalian target of rapamycin (mTOR) is a serine/threonine kinase involved in multiple intracellular signaling pathways promoting tumor growth. mTOR is aberrantly activated in a significant portion of breast cancers and is a promising target for treatment. Rapamycin and its analogues are in clinical trials for breast cancer treatment. Patterns of gene expression (metagenes) may also be used to simulate a biologic process or effects of a drug treatment. In this study,we tested the hypothesis that the gene-expression signature regulated by rapamycin could predict disease outcome for patients with breast cancer. RESULTS: Colony formation and sulforhodamine B (IC50 textless 1 nM) assays,and xenograft animals showed that MDA-MB-468 cells were sensitive to treatment with rapamycin. The comparison of in vitro and in vivo gene expression data identified a signature,termed rapamycin metagene index (RMI),of 31 genes upregulated by rapamycin treatment in vitro as well as in vivo (false discovery rate of 10%). In the Miller dataset,RMI did not correlate with tumor size or lymph node status. High (textgreater75th percentile) RMI was significantly associated with longer survival (P = 0.015). On multivariate analysis,RMI (P = 0.029),tumor size (P = 0.015) and lymph node status (P = 0.001) were prognostic. In van 't Veer study,RMI was not associated with the time to develop distant metastasis (P = 0.41). In the Wang dataset,RMI predicted time to disease relapse (P = 0.009). CONCLUSION: Rapamycin-regulated gene expression signature predicts clinical outcome in breast cancer. This supports the central role of mTOR signaling in breast cancer biology and provides further impetus to pursue mTOR-targeted therapies for breast cancer treatment. View Publication

PURPOSE: Genz-644282 [8,9-dimethoxy-5-(2-N-methylaminoethyl)-2,3-methylenedioxy-5H-dibenzo[c,h][1,6]naphthyridin-6-one] has emerged as a promising candidate for antitumor agents. This report describes the bone marrow colony-forming unit,granulocyte macrophage (CFU-GM) and tumor cell CFU activity of topoisomerase I (Top1) inhibitors,such as Genz-644282,topotecan,irinotecan/SN-38,and ARC-111,and examines their activity in several human tumor xenograft models. EXPERIMENTAL DESIGN: Colony-forming assays were conducted with mouse and human bone marrow and eight human tumor cell lines. In addition,29 human tumor cell lines representing a range of histology and potential resistance mechanisms were assayed for sensitivity to Genz-644282 in a 72-hour exposure assay. The efficacy of Genz-644282 was compared with standard anticancer drugs (i.e.,irinotecan,docetaxel,and dacarbazine) in human tumor xenografts of colon cancer,renal cell carcinoma,non-small cell lung cancer,and melanoma. RESULTS: Human bone marrow CFU-GM was more sensitive to the Top1 inhibitors than was mouse bone marrow CFU-GM. The ratio of mouse to human IC(90) values was more than 10 for the camptothecins and less than 10 for Genz-644282,which had more potency as a cytotoxic agent toward human tumor cells in culture than the camptothecins in the colony-forming and 72-hour proliferation assays. Genz-644282 has superior or equal antitumor activity in the human tumor xenografts than the standard drug comparators. CONCLUSIONS: On the basis of preclinical activity and safety,Genz-644282 was selected for development and is currently undergoing phase 1 clinical trial. View Publication

Aldehyde dehydrogenase (ALDH) activity has been implicated in multiple biological and biochemical pathways and has been used to identify potential cancer stem cells. Our main hypothesis is that ALDH activity may be a lung cancer stem cell marker. Using flow cytometry,we sorted cells with bright (ALDH(br)) and dim (ALDH(lo)) ALDH activity found in H522 lung cancer cell line. We used in vitro proliferation and colony assays as well as a xenograft animal model to test our hypothesis. Cytogenetic analysis demonstrated that the ALDH(br) cells are indeed a different clone,but when left in normal culture conditions will give rise to ALDH(lo) cells. Furthermore,the ALDH(br) cells grow slower,have low clonal efficiency,and give rise to morphologically distinct colonies. The ability to form primary xenografts in NOD/SCID mice by ALDH(br) and ALDH(lo) cells was tested by injecting single cell suspension under the skin in each flank of same animal. Tumor size was calculated weekly. ALDH1A1 and ALDH3A1 immunohistochemistry (IHC) was performed on excised tumors. These tumors were also used to re-establish cell suspension,measure ALDH activity,and re-injection for secondary and tertiary transplants. The results indicate that both cell types can form tumors but the ones from ALDH(br) cells grew much slower in primary recipient mice. Histologically,there was no significant difference in the expression of ALDH in primary tumors originating from ALDH(br) or ALDH(lo) cells. Secondary and tertiary xenografts originating from ALDH(br) grew faster and bigger than those formed by ALDH(lo) cells. In conclusion,ALDH(br) cells may have some of the traditional features of stem cells in terms of being mostly dormant and slow to divide,but require support of other cells (ALDH(lo)) to sustain tumor growth. These observations and the known role of ALDH in drug resistance may have significant therapeutic implications in the treatment of lung cancer. View Publication

Recent research in breast biology has provided support for the cancer stem-cell hypothesis. Two important components of this hypothesis are that tumors originate in mammary stem or progenitor cells as a result of dysregulation of the normally tightly regulated process of self-renewal. As a result,tumors contain and are driven by a cellular subcomponent that retains key stem-cell properties including self-renewal,which drives tumorigenesis and differentiation that contributes to cellular heterogeneity. Advances in stem-cell technology have led to the identification of stem cells in normal and malignant breast tissue. The study of these stem cells has helped to elucidate the origin of the molecular complexity of human breast cancer. The cancer stem-cell hypothesis has important implications for early detection,prevention,and treatment of breast cancer. Both hereditary and sporadic breast cancers may develop through dysregulation of stem-cell self-renewal pathways. These aberrant stem cells may provide targets for the development of cancer prevention strategies. Furthermore,because breast cancer stem cells may be highly resistant to radiation and chemotherapy,the development of more effective therapies for this disease may require the effective targeting of this cell population. View Publication