Ibarra I et al. (DEC 2007)
Genes & development 21 24 3238--43
A role for microRNAs in maintenance of mouse mammary epithelial progenitor cells.
microRNA (miRNA) expression profiles are often characteristic of specific cell types. The mouse mammary epithelial cell line,Comma-Dbeta,contains a population of self-renewing progenitor cells that can reconstitute the mammary gland. We purified this population and determined its miRNA signature. Several microRNAs,including miR-205 and miR-22,are highly expressed in mammary progenitor cells,while others,including let-7 and miR-93,are depleted. Let-7 sensors can be used to prospectively enrich self-renewing populations,and enforced let-7 expression induces loss of self-renewing cells from mixed cultures.
View Publication
产品类型:
产品号#:
01700
01705
01702
产品名:
ALDEFLUOR™ 试剂盒
ALDEFLUOR™ DEAB试剂
ALDEFLUOR™测定缓冲液
文献
Bruserud &O et al. (MAY 2003)
Leukemia research 27 5 455--64
In vitro culture of human acute lymphoblastic leukemia (ALL) cells in serum-free media; a comparison of native ALL blasts, ALL cell lines and virus-transformed B cell lines.
The aim of this study was to standardize in vitro culture conditions for human acute lymphoblastic leukemia (ALL) cells. The cells were cultured in medium containing 10% fetal calf serum (FCS) and in the four serum-free media X-vivo 10,X-vivo 15,X-vivo 20 and Stem Span. Native ALL blasts could proliferate in all four serum-free media,but the strongest responses were usually observed with Stem Span. Native leukemia blasts were also cultured in the presence of various single cytokines or cytokine combinations. The highest proliferation was usually observed in the presence of Flt3-Ligand (Flt3-L) when single cytokines were examined,and these responses could be further increased especially by combining Flt3-L with interleukin 3 (IL3),IL7 or stem cell factor (SCF). Proliferation could also be increased when ALL blasts were cultured in the presence of two commercially available fibroblast cell lines (Hs27 and HFL1). Based on these results we suggest that in vitro culture conditions for native human ALL blasts can be standardized by using serum-free culture media supplemented with exogenous Flt3-L+IL3+SCF,and the use of accessory cells can also be standardized by using well-characterized fibroblast cell lines. Detectable ALL blast proliferation can then be observed for most patients. Our experimental model can thereby be used for in vitro evaluation of possible antileukemic treatment strategies,and it will then allow comparison of experimental results between different studies.
View Publication
Finstad SL et al. (JUL 2007)
Journal of virology 81 13 7274--9
Diminished potential for B-lymphoid differentiation after murine leukemia virus infection in vivo and in EML hematopoietic progenitor cells.
Infection with a recombinant murine-feline gammaretrovirus,MoFe2,or with the parent virus,Moloney murine leukemia virus,caused significant reduction in B-lymphoid differentiation of bone marrow at 2 to 8 weeks postinfection. The suppression was selective,in that myeloid potential was significantly increased by infection. Analysis of cell surface markers and immunoglobulin H gene rearrangements in an in vitro model demonstrated normal B-lymphoid differentiation after infection but significantly reduced viability of differentiating cells. This reduction in viability may confer a selective advantage on undifferentiated lymphoid progenitors in the bone marrow of gammaretrovirus-infected animals and thereby contribute to the establishment of a premalignant state.
View Publication
Akatsuka A et al. (SEP 2010)
International immunology 22 9 783--90
Tumor cells of non-hematopoietic and hematopoietic origins express activation-induced C-type lectin, the ligand for killer cell lectin-like receptor F1.
Killer cell lectin-like receptor F1 (KLRF1) is an activating C-type lectin-like receptor expressed on human NK cells and subsets of T cells. In this study,we show that activation-induced C-type lectin (AICL) is a unique KLRF1 ligand expressed on tumor cell lines of hematopoietic and non-hematopoietic origins. We screened a panel of human tumor cell lines using the KLRF1 reporter cells and found that several tumor lines expressed KLRF1 ligands. We characterized a putative KLRF1 ligand expressed on the U937 cell line. The molecular mass for the deglycosylated ligand was 28 kDa under non-reducing condition and 17 kDa under reducing condition,suggesting that the KLRF1 ligand is a homodimer. By expression cloning from a U937 cDNA library,we identified AICL as a KLRF1 ligand. We generated mAbs against AICL to identify the KLRF1 ligands on non-hematopoietic tumor lines. The anti-AICL mAbs stained the tumor lines that express the KLRF1 ligands and importantly the interaction of KLRF1 with the KLRF1 ligand on non-hematopoietic tumors was completely blocked by the two anti-AICL mAbs. Moreover,NK cell degranulation triggered by AICL-expressing targets was partially inhibited by the anti-AICL mAb. Finally,we demonstrate that AICL is expressed in human primary liver cancers. These results suggest that AICL is expressed on tumor cells of non-hematopoietic origins and raise the possibility that AICL may contribute to NK cell surveillance of tumor cells.
View Publication
产品类型:
产品号#:
产品名:
文献
Hawley RG et al. (JAN 2006)
Methods in enzymology 419 149--79
Hematopoietic stem cells.
Hematopoietic stem cells (HSCs) have the capacity to self-renew and the potential to differentiate into all of the mature blood cell types. The ability to prospectively identify and isolate HSCs has been the subject of extensive investigation since the first transplantation studies implying their existence almost 50 years ago. Despite significant advances in enrichment protocols,the continuous in vitro propagation of human HSCs has not yet been achieved. This chapter describes current procedures used to phenotypically and functionally characterize candidate human HSCs and initial efforts to derive permanent human HSC lines.
View Publication
Bruserud O et al. (DEC 2000)
Journal of hematotherapy & stem cell research 9 6 923--32
In vitro culture of human acute myelogenous leukemia (AML) cells in serum-free media: studies of native AML blasts and AML cell lines.
The functional characteristics were compared for acute myelogenous leukemia (AML) cells (native blasts and AML cell lines) cultured in three serum-free media (X-vivo 10,X-vivo 15,[Bio-Whitacker,Walkersville,MD] and StemSpan [Stem Cell Technologies,Vancouver,BC,Canada]) and in medium containing 10% inactivated fetal calf serum (FCS). For native AML blasts the following functions were compared: (1) autonomous and cytokine-dependent proliferation; (2) frequency of clonogenic cell; and (3) constitutive cytokine secretion. AML blast proliferation differed between patients independent of the culture medium used,and clonogenic cells were maintained after in vitro culture in all media. In contrast,constitutive cytokine secretion was higher for cells cultured in StemSpan and FCS-containing medium than for cells cultured in the X-vivo media. Native AML blasts incubated in StemSpan also showed a low frequency of apoptotic cells. The three serum-free media could also be used for long-term expansion of well-characterized AML cell lines,but the optimal medium for cell expansion and cytokine secretion differed between cell lines. We conclude that standardized serum-free culture conditions can be used for in vitro studies of native AML blasts and AML cell lines.
View Publication
产品类型:
产品号#:
09600
09650
产品名:
StemSpan™ SFEM
StemSpan™ SFEM
文献
Kharas MG et al. (JUN 2004)
Blood 103 11 4268--75
Phosphoinositide 3-kinase signaling is essential for ABL oncogene-mediated transformation of B-lineage cells.
BCR-ABL and v-ABL are oncogenic forms of the Abl tyrosine kinase that can cause leukemias in mice and humans. ABL oncogenes trigger multiple signaling pathways whose contribution to transformation varies among cell types. Activation of phosphoinositide 3-kinase (PI3K) is essential for ABL-dependent proliferation and survival in some cell types,and global PI3K inhibitors can enhance the antileukemia effects of the Abl kinase inhibitor imatinib. Although a significant fraction of BCR-ABL-induced human leukemias are of B-cell origin,little is known about PI3K signaling mechanisms in B-lineage cells transformed by ABL oncogenes. Here we show that activation of class I(A) PI3K and downstream inactivation of FOXO transcription factors are essential for survival of murine pro/pre-B cells transformed by v-ABL or BCR-ABL. In addition,analysis of mice lacking individual PI3K genes indicates that products of the Pik3r1 gene contribute to transformation efficiency by BCR-ABL. These findings establish a role for PI3K signaling in B-lineage transformation by ABL oncogenes.
View Publication
产品类型:
产品号#:
03630
产品名:
MethoCult™M3630
文献
Qué et al. (JUN 2011)
Blood 117 22 5918--30
Smad4 binds Hoxa9 in the cytoplasm and protects primitive hematopoietic cells against nuclear activation by Hoxa9 and leukemia transformation.
We studied leukemic stem cells (LSCs) in a Smad4(-/-) mouse model of acute myelogenous leukemia (AML) induced either by the HOXA9 gene or by the fusion oncogene NUP98-HOXA9. Although Hoxa9-Smad4 complexes accumulate in the cytoplasm of normal hematopoietic stem cells and progenitor cells (HSPCs) transduced with these oncogenes,there is no cytoplasmic stabilization of HOXA9 in Smad4(-/-) HSPCs,and as a consequence increased levels of Hoxa9 is observed in the nucleus leading to increased immortalization in vitro. Loss of Smad4 accelerates the development of leukemia in vivo because of an increase in transformation of HSPCs. Therefore,the cytoplasmic binding of Hoxa9 by Smad4 is a mechanism to protect Hoxa9-induced transformation of normal HSPCs. Because Smad4 is a potent tumor suppressor involved in growth control,we developed a strategy to modify the subcellular distribution of Smad4. We successfully disrupted the interaction between Hoxa9 and Smad4 to activate the TGF-β pathway and apoptosis,leading to a loss of LSCs. Together,these findings reveal a major role for Smad4 in the negative regulation of leukemia initiation and maintenance induced by HOXA9/NUP98-HOXA9 and provide strong evidence that antagonizing Smad4 stabilization by these oncoproteins might be a promising novel therapeutic approach in leukemia.
View Publication
产品类型:
产品号#:
03434
03444
03236
产品名:
MethoCult™GF M3434
MethoCult™GF M3434
MethoCult™SF M3236
文献
Mortensen M et al. (MAR 2011)
The Journal of experimental medicine 208 3 455--67
The autophagy protein Atg7 is essential for hematopoietic stem cell maintenance.
The role of autophagy,a lysosomal degradation pathway which prevents cellular damage,in the maintenance of adult mouse hematopoietic stem cells (HSCs) remains unknown. Although normal HSCs sustain life-long hematopoiesis,malignant transformation of HSCs leads to leukemia. Therefore,mechanisms protecting HSCs from cellular damage are essential to prevent hematopoietic malignancies. In this study,we crippled autophagy in HSCs by conditionally deleting the essential autophagy gene Atg7 in the hematopoietic system. This resulted in the loss of normal HSC functions,a severe myeloproliferation,and death of the mice within weeks. The hematopoietic stem and progenitor cell compartment displayed an accumulation of mitochondria and reactive oxygen species,as well as increased proliferation and DNA damage. HSCs within the Lin(-)Sca-1(+)c-Kit(+) (LSK) compartment were significantly reduced. Although the overall LSK compartment was expanded,Atg7-deficient LSK cells failed to reconstitute the hematopoietic system of lethally irradiated mice. Consistent with loss of HSC functions,the production of both lymphoid and myeloid progenitors was impaired in the absence of Atg7. Collectively,these data show that Atg7 is an essential regulator of adult HSC maintenance.
View Publication