Myeloid-Derived Suppressive Cells Belonging to the Leukemic Clone Account for Immunosuppression In CMML

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3997-3997 ◽  
Author(s):  
Nathalie Droin ◽  
Raphael Itzykson ◽  
Philippe Rameau ◽  
Margot Morabito ◽  
Thorsten Braun ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Research Funding ◽  
Purinergic Receptor ◽  
Mrna Level ◽  
Cyclin D3 ◽  
Cell Contact ◽  
Arginase 1 ◽  
Leukemic Clone

Abstract Abstract 3997 We have shown previously that cells identified as monocytes in the peripheral blood of patients with chronic myelomonocytic leukemia (CMLL) included a variable proportion of CD14-negative, CD24-positive immature granulocytes. These cells synthesize and secrete alpha-defensin 1–3 that inhibit M-CSF-driven monocyte differentiation into macrophages through interaction with the P2Y6 purinergic receptor (Droin N et al, Blood 2010). In the present study, we show that these CD14-,CD24+ immature granulocytes also inhibit the proliferation of autologous lymphocytes activated with anti-CD3 and anti-CD28 antibodies through cell-cell contact. This functional property suggested that these cells could be “myeloid-derived suppressive cells” (MDSC), which was supported by their phenotype that included expression of CD15 marker at their surface and survivin, S100A8 and S100A9, Cyclin D2 and Cyclin D3 at the mRNA level. STAT3 and STAT6 were found constitutively phosphorylated in these immature granulocytes that responded to Toll-like receptor agonists such as LPS or Pam-6. CD14-positive monocytes of the leukemic clone activated these MDSC through production of IL-13 and induction of arginase 1 mRNA, which could be reproduced by recombinant IL-13. On the other hand, activation of these MDSC did not require induction of the nitric oxide synthase mRNA, in agreement with their granulocytic origin. We were able to generate immature myeloid cells expressing CD24 with morphology similar to that of peripheral blood MDSC by in vitro culture of various subpopulations of bone marrow CD34-positive cells obtained from CMML patients, including the most immature CD34+/CD38-/CD90+ cells. Furthermore, generation of these cells could be recapitulated in vivo by xenotransplantation of CMML CD34+ cells in NOG mice, albeit with lower efficacy than CD14+ cells. In patients with high grade CMML included in a phase II clinical trial, decitabine was observed to decrease both CD14+,CD24- monocytes and CD14-,CD24+ immature granulocytes. Altogether, these data suggest that CMML initiating cells generate CD14-positive monocytes and, in most patients, an additional population of CD14-negative immature granulocytes with suppressive properties towards innate and acquired immune response. Generation of these cells may account for the high sensitivity of CMML patients to autoimmune and infectious diseases. Disclosures: Fenaux: Celgene: Honoraria, Research Funding; Novartis: Honoraria, Research Funding; Janssen Cilag: Honoraria, Research Funding; ROCHE: Honoraria, Research Funding; AMGEN: Honoraria, Research Funding; GSK: Honoraria, Research Funding; Merck: Honoraria, Research Funding; Cephalon: Honoraria, Research Funding.

Constitutive and Immunoproteasome Inhibitors Increase IκB and Decrease NF-κB Expression In Dendritic Cell

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3493-3493
Author(s):  
Ahmad-Samer Samer Al-Homsi ◽  
Zhongbin Lai ◽  
Tara Sabrina Roy ◽  
Niholas Kouttab
Keyword(s):  
Multiple Myeloma ◽  
T Cell ◽  
Cell Lines ◽  
Mechanism Of Action ◽  
Peripheral Blood ◽  
Research Funding ◽  
Myeloma Cell ◽  
Multiple Myeloma Cell

Abstract Introduction Constitutive and immunoproteasome inhibitors (C&IPI) were thought to suppress nuclear factor-κB (NF-κB) pathway by preventing IκB degradation, which prevents NF-κB translocation into the nucleus. This mechanism of action has since been questioned by a number of studies. First, bortezomib promoted constitutive NF-κB activity in endothelial cell carcinoma. Second, NF-κB constitutive activity was resistant to bortezomib in multiple myeloma cell lines. Third, bortezomib increased IκB mRNA but post-transcriptionally downregulated IκB in normal cells and in multiple myeloma cell lines resulting in induced canonical NF-κB activation. Lastly, bortezomib increased nuclear levels of IκB as opposed to lowering cytoplasmic levels in cutaneous T cell lymphoma cell line suggesting that nuclear translocation of IκB was possibly responsible for NF-κB inhibition. The inhibitory activity of C&IPI on dendritic cells (DC) is of interest in the prevention of graft versus host disease (GvHD). It has been shown that different C&IPI impede DC maturation and T cell priming both in vitro and in vivo. Herein we sought to understand the mechanism of action of proteasome and immunoproteasome inhibitors on DC and to test their effect on IκB and NF-IκB expression. Materials and Methods We first performed RT PCR on lysates of DC obtained from the peripheral blood of 7 patients who received post-transplant cyclophosphamide and bortezomib as prevention of GvHD on a phase I clinical trial. Patients received allogeneic transplantation from matched-related or unrelated donors. Patients received no other immunosuppressive therapy except for rabbit anti-thymocyte globulin for those receiving graft from unrelated donor. Steroids were not allowed on the study. Samples were obtained on days +1, +4, and +7. The results were analyzed in comparison to samples obtained on day 0 before stem cell infusion. We then performed the same experiment on lysates of DC obtained from the peripheral blood of healthy volunteer donors. DC were untreated or incubated with bortezomib (10 nM for 4 h), carfilzomib (30 nM for 1 h), oprozomib (100 nM and 300 nM for 4 h), ONX 0914 (200 nM for 1 h), PR-825 (125 nM for 1 h), or PR-924 (1000 nM for 1 h). The drug concentration and duration of exposure were chosen based on the IC50 on proteasome activity and to reproduce in vivo conditions. We also performed IκB western blot on DC isolated from peripheral blood of healthy volunteers, untreated or incubated with bortezomib (10 nM for 4 h) or oprozomib (300 nM for 4 h). Each experiment was performed at least in triplicate. Results We found that the combination of cyclophosphamide and bortezomib significantly and progressively increased IκB mRNA while decreasing NF-κB mRNA in DC studied ex vivo. We also found that all studied C&IPI increased IκB mRNA to a variable degree while only oprozomib (300 nM) decreased NF-κB mRNA in DC in vitro. Finally, both bortezomib and oprozomib increased IκB protein level in DC in vitro (figure). Conclusion Our data suggest that C&IPI increase IκB expression in DC. As opposed to the previously reported data in other cell types, the effect is not associated with post-transcriptional downregulation. Cyclophosphamide and bortezomib also decrease NF-κB expression in DC in vivo while only oprozomib had the same effect in vitro. The effect of C&IPI on IκB and NF-κB expression may represent a new mechanism of action and suggests their effect may be cell-type dependent. Disclosures: Al-Homsi: Millennium Pharmaceuticals: Research Funding. Off Label Use: The use of cyclophosphamide and bortezomib for GvHD prevention. Lai:Millennium Pharmaceuticals: Research Funding.

A Neutralizing Antibody (CSL362) Against the Interleukin-3 Receptor α-Chain Augments the Efficacy of a Cytarabine/Daunorubicin Induction-Type Therapy in Preclinical Xenograft Models of Acute Myelogenous Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 3599-3599 ◽  
Author(s):  
Erwin M Lee ◽  
Dean Yee ◽  
Samantha J Busfield ◽  
Gino Vairo ◽  
Richard B. Lock
Keyword(s):  
Adoptive Transfer ◽  
Peripheral Blood ◽  
Research Funding ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Myelogenous Leukemia ◽  
Nsg Mice ◽  
Induction Type

Abstract Abstract 3599 Introduction: Despite the development of many new agents for the treatment of acute myelogenous leukemia (AML), the prognosis for most patients remains dismal. The interleukin-3 receptor α chain (IL-3Rα, CD123) is highly expressed on the surface of acute and chronic leukemias compared with normal hematopoietic stem cells, providing a rational therapeutic target. CSL362 is a fully humanized, second generation, neutralizing monoclonal antibody targeting CD123 that contains a modified Fc region to enhance human natural killer (huNK) cell-mediated antibody dependent cellular cytotoxicity (ADCC). The purpose of this study was to test the in vivo efficacy of CSL362 in combination with an induction-type chemotherapy regimen and adoptive transfer of huNK cells against xenograft models of human AML. Methods: Direct patient explants of 5 AML samples with defined genetic lesions were established as continuous xenografts in sub-lethally irradiated immune-deficient NOD/SCID or NSG mice. In order to complement the clinical development of CSL362 we optimized an induction-type regimen of cytarabine (AraC, 25 mg/kg IP daily × 4 × 2 weeks) combined with daunorubicin (DNR, 0.62 mg/kg IV weekly × 2 weeks) to simulate the complex biology of AML in a post-chemotherapy setting. For adoptive transplantation into AML engrafted mice, primary huNK cells were expanded 600- to 700-fold in vitro by culturing on feeder cells in the presence of IL-2 for 21 days. In efficacy experiments, an event was defined a priori to occur when the % human CD45 cells in the peripheral blood (%huCD45) reached 25%. Results: Human AML xenografts consistently and predictably produced progressive and disseminating disease in the peripheral blood, bone marrow, spleen, liver, kidneys, lungs and brain of mice between 42 and 200 days post-transplantation. Disease progression represented by increasing percentages of human CD45+ cells in the peripheral blood (%huCD45) inversely correlated with murine red blood cell and platelet counts, and mouse hematocrit and hemoglobin levels. The immunophenotype and gene expression profiles of each xenograft were comparable with the respective original patient samples, indicating that the xenografts provide a valid representation of the human disease. In vitro co-cultures of AML xenograft cells with CD56+/CD16+ huNK cells (5 h at a 1:10 ratio) resulted in an average AML cell death of 18% (range 7–38%). The addition of CSL362 (10 μg/ml) resulted in an average 26% (range 2–64%) increase in AML cell death compared with huNK alone. In vivo AraC/DNR treatment significantly extended the event-free survival (EFS) of mice engrafted with 3/3 AML xenografts by between 32 and 41 days compared with vehicle-treated control mice (P < 0.0001). The addition of CSL362 (300μg IP thrice weekly × 2) significantly extended the median EFS of AraC/DNR-treated mice by 5.9 days (P = 0.002). Moreover, while the adoptive transfer of huNK cells (20 million IV × 2) resulted in no significant survival advantage, huNK cells administered with CSL362 further prolonged mouse EFS by 15.2 days compared with chemotherapy alone (P = 0.0004), providing evidence of therapeutic enhancement. Conclusion: AML xenografts established in NOD/SCID or NSG mice from direct patient explants provide a clinically relevant experimental model for preclinical drug testing, and reflect the immunophenotype and gene expression profiles of the original biopsy specimen. CSL362 treatment of AML xenografted mice augments the efficacy of an induction-type therapy, with additional therapeutic enhancement achieved by the adoptive transfer of huNK cells. These data support the rationale for CSL362 treatment of AML patients post remission induction in an upcoming clinical trial. Disclosures: Lee: CSL Limited: Research Funding. Yee:CSL Limited: Research Funding. Busfield:CSL Limited: Employment. Vairo:CSL Limited: Employment. Lock:CSL Limited: Consultancy, Research Funding.

scholarly journals Ibrutinib Disrupts the Metabolic Program of CLL Cells in-Vivo

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 4348-4348
Author(s):  
Uri Rozovski ◽  
David M. Harris ◽  
Ping LI ◽  
Zhiming Liu ◽  
Preetesh Jain ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
B Cell ◽  
Peripheral Blood ◽  
Research Funding ◽  
Metabolic Reprogramming ◽  
Short Exposure ◽  
Dependent Manner ◽  
Ffa Metabolism

Abstract Introduction: Unlike their normal resting B cell counterparts, chronic lymphocytic leukemia (CLL) cells proliferate. Approximately 1% of the total CLL cell clone expands daily. To adjust for the increase in energetic demands imposed by continuous proliferation, CLL cells undergo metabolic reprogramming and, as recently shown (Rozovski U, et al. Mol Cancer Res. 2015; 13:944-53), CLL cells utilize fat in a manner similar to that of adipocytes. The recent introduction of the oral Bruton tyrosine kinase inhibitor (BTK) ibrutinib revolutionized the treatment of CLL. Because the proliferation of CLL cells is driven by lipid metabolism and ibrutinib inhibits the B cell receptor-induced proliferation of CLL cells, we sought to determine whether ibrutinib also disrupts the metabolic program that provides CLL cells with their unique energy requirements. Methods: We prospectively studied serial peripheral blood samples from 16 patients with CLL. The patients' peripheral blood CLL cells were analyzed prior to and during treatment with ibrutinib. All patients received a daily dose of 420 mg ibrutinib. In addition, we performed in vitro studies using CLL cells from 3 ibrutinib-naïve patients. CLL cells were analyzed for free-fatty acids (FFA) consumption and for the rate of cellular apoptosis using propiduim iodide (PI) and annexin V staining analyzed by flow cytometry. Results: To study lipid metabolism of CLL cells we incubated peripheral blood CLL cells from 3 randomly selected ibrutinib-naïve patients in the presence or absence of FFA and measured the concentration of culture media-dissolved O2 (dO2). Like in our previous study (Rozovski U, et al. Mol Cancer Res. 2015; 13:944-53), we found that CLL cells metabolized FFA and, as a result, the levels of dO2 decreased. However when the cells were co-cultured with FFA and ibrutinib, the delta dO2 (dO2 with FFA minus dO2 without FFA) remained unchanged, suggesting that ibrutinib blocked FFA metabolism in CLL cells.Then, to determine whether ibrutinib also inhibited CLL-cell lipid metabolism in patients treated with ibrutinib, we collected 2 to 5 consecutive PB samples (median: 5) from 16 CLL patients prior to and during treatment with ibrutinib. Unlike the 12% reduction in delta dO2 detected in untreated patients' CLL cells incubated with FFA in vitro, a 6% reduction in delta dO2 was detected in CLL cells of patients treated with ibrutinib 4 days into treatment and after a median of 147 days of ibrutinib treatment a change in delta dO2 was no longer detected. These data suggest that ibrutinib-treated cells lost their capacity to utilize FFA or that the number of FFA consuming circulating CLL cells declined until they were no longer detected. In addition, whereas ibrutinib induced apoptosis of CLL cells in a dose-dependent manner in vitro, ibrutinib did not induce apoptosis at the same time points in vivo, suggesting that interruption of FFA metabolism does not lead to apoptotic cell death and that the metabolic and proapoptotic pathways are not linearly intertwined in CLL cells. In conclusion: Treatment with ibrutinib changes the metabolic profile CLL cells. Even after short exposure to the drug the cells were less capable of utilizing FFA, and after longer exposure, the cells could no longer utilize FFA. Whether ibrutinib induced reduction in FFA metabolism decreases the proliferation capacity of CLL cells remains to be determined. Disclosures Burger: Pharmacyclics: Research Funding. O'Brien:Janssen: Consultancy, Honoraria; Pharmacyclics, LLC, an AbbVie Company: Consultancy, Honoraria, Research Funding. Jain:Pfizer: Consultancy, Honoraria, Research Funding; Celgene: Research Funding; Abbvie: Research Funding; Novimmune: Consultancy, Honoraria; Servier: Consultancy, Honoraria; Incyte: Research Funding; ADC Therapeutics: Consultancy, Honoraria, Research Funding; Seattle Genetics: Research Funding; Genentech: Research Funding; BMS: Research Funding; Pharmacyclics: Consultancy, Honoraria, Research Funding; Infinity: Research Funding; Novartis: Consultancy, Honoraria. Wierda:Novartis: Research Funding; Abbvie: Research Funding; Acerta: Research Funding; Gilead: Research Funding; Genentech: Research Funding.

scholarly journals Human Cd25+Cd4+ T Regulatory Cells Suppress Naive and Memory T Cell Proliferation and Can Be Expanded in Vitro without Loss of Function

2001 ◽  
Vol 193 (11) ◽  
pp. 1295-1302 ◽  
Author(s):  
Megan K. Levings ◽  
Romina Sangregorio ◽  
Maria-Grazia Roncarolo
Keyword(s):  
T Cell ◽  
Peripheral Blood ◽  
T Regulatory Cells ◽  
Transforming Growth Factor ◽  
Cytotoxic T Lymphocyte ◽  
Cell Receptor ◽  
Major Advance ◽  
Loss Of Function

Active suppression by T regulatory (Tr) cells plays an important role in the downregulation of T cell responses to foreign and self-antigens. Mouse CD4+ Tr cells that express CD25 possess remarkable suppressive activity in vitro and in autoimmune disease models in vivo. Thus far, the existence of a similar subset of CD25+CD4+ Tr cells in humans has not been reported. Here we show that human CD25+CD4+ Tr cells isolated from peripheral blood failed to proliferate and displayed reduced expression of CD40 ligand (CD40L), in response to T cell receptor–mediated polyclonal activation, but strongly upregulated cytotoxic T lymphocyte–associated antigen (CTLA)-4. Human CD25+CD4+ Tr cells also did not proliferate in response to allogeneic antigen-presenting cells, but they produced interleukin (IL)-10, transforming growth factor (TGF)-β, low levels of interferon (IFN)-γ, and no IL-4 or IL-2. Importantly, CD25+CD4+ Tr cells strongly inhibited the proliferative responses of both naive and memory CD4+ T cells to alloantigens, but neither IL-10, TGF-β, nor CTLA-4 seemed to be directly required for their suppressive effects. CD25+CD4+ Tr cells could be expanded in vitro in the presence of IL-2 and allogeneic feeder cells and maintained their suppressive capacities. These findings that CD25+CD4+ Tr cells with immunosuppressive effects can be isolated from peripheral blood and expanded in vitro without loss of function represent a major advance towards the therapeutic use of these cells in T cell–mediated diseases.

scholarly journals Primitive Human Hematopoietic Cells Are Enriched in Cord Blood Compared With Adult Bone Marrow or Mobilized Peripheral Blood as Measured by the Quantitative In Vivo SCID-Repopulating Cell Assay

Blood ◽  
1997 ◽  
Vol 89 (11) ◽  
pp. 3919-3924 ◽  
Author(s):  
Jean C.Y. Wang ◽  
Monica Doedens ◽  
John E. Dick
Keyword(s):  
Bone Marrow ◽  
Cord Blood ◽  
Peripheral Blood ◽  
Hematopoietic Cells ◽  
Allogeneic Transplantation ◽  
Functional Assay ◽  
Hematopoietic Stem ◽  
Mobilized Peripheral Blood

Abstract We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay, the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 × 105 cells. This was significantly higher than the frequency of 1 SRC in 3.0 × 106 adult BM cells or 1 in 6.0 × 106 mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus, the findings reported here will have important clinical as well as biologic implications.

scholarly journals The Potential Role of IL1RAP on Tumor Microenvironment-Related Inflammatory Factors in Stomach Adenocarcinoma

2021 ◽  
Vol 20 ◽  
pp. 153303382199528
Author(s):  
Qing Lv ◽  
Qinghua Xia ◽  
Anshu Li ◽  
Zhiyong Wang
Keyword(s):  
Tumor Microenvironment ◽  
Interleukin 1 ◽  
Mrna Level ◽  
Inflammatory Factors ◽  
Stomach Carcinoma ◽  
Downstream Target ◽  
Volume Weight

This study was performed to investigate the role of interleukin-1 receptor accessory protein (IL1RAP) in stomach carcinoma in vitro and in vivo, determine whether IL1RAP knockdown could regulate the development of stomach carcinoma, and elucidate the relationship between IL1RAP knockdown and inflammation by tumor microenvironment-related inflammatory factors in stomach carcinoma. We first used TCGA and GEPIA systems to predict the potential function of IL1RAP. Second, western blot and RT-PCR were used to analyze the expression, or mRNA level, of IL1RAP at different tissue or cell lines. Third, the occurrence and development of stomach carcinoma in vitro and in vivo were observed by using IL1RAP knockdown lentivirus. Finally, the inflammation of stomach carcinoma in vitro and in vivo was observed. Results show that in GEPIA and TCGA systems, IL1RAP expression in STAD tumor tissue was higher than normal, and high expression of IL1RAP in STAD patients had a worse prognostic outcome. Besides, GSEA shown IL1RAP was negative correlation of apopopsis, TLR4 and NF-κB signaling pathway. We also predicted that IL1RAP may related to IL-1 s, IL-33, and IL-36 s in STAD. The IL1RAP expression and mRNA level in tumor, or MGC803, cells were increased. Furthermore, IL1RAP knockdown by lentivirus could inhibit stomach carcinoma development in vitro and in vivo through weakening tumor cell proliferation, migration, invasion, therefore reducing tumor volume, weight, and biomarker levels, and increasing apoptotic level. Finally, we found IL1RAP knockdown could increase inflammation of tumor microenvironment-related inflammatory factors of stomach carcinoma, in vitro and in vivo. Our study demonstrates that IL1RAP is possibly able to regulate inflammation and apoptosis in stomach carcinoma. Furthermore, TLR4, NF-κB, IL-1 s, IL-33, and IL-36 s maybe the downstream target factor of IL1RAP in inflammation. These results may provide a new strategy for stomach carcinoma development by regulating inflammation.

scholarly journals Bone marrow mesenchymal stem cells promote prostate cancer cell stemness via cell–cell contact to activate the Jagged1/Notch1 pathway

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ji-wen Cheng ◽  
Li-xia Duan ◽  
Yang Yu ◽  
Pu Wang ◽  
Jia-le Feng ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Western Blot ◽  
Cell Contact ◽  
Activity Levels ◽  
Tumor Resistance ◽  
Cell Cell

Abstract Background Mesenchymal stem cells (MSCs) play a crucial role in cancer development and tumor resistance to therapy in prostate cancer, but the influence of MSCs on the stemness potential of PCa cells by cell–cell contact remains unclear. In this study, we investigated the effect of direct contact of PCa cells with MSCs on the stemness of PCa and its mechanisms. Methods First, the flow cytometry, colony formation, and sphere formation were performed to determine the stemness of PCaMSCs, and the expression of stemness-related molecules (Sox2, Oct4, and Nanog) was investigated by western blot analysis. Then, we used western blot and qPCR to determine the activity levels of two candidate pathways and their downstream stemness-associated pathway. Finally, we verified the role of the significantly changed pathway by assessing the key factors in this pathway via in vitro and in vivo experiments. Results We established that MSCs promoted the stemness of PCa cells by cell–cell contact. We here established that the enhanced stemness of PCaMSCs was independent of the CCL5/CCR5 pathway. We also found that PCaMSCs up-regulated the expression of Notch signaling-related genes, and inhibition of Jagged1-Notch1 signaling in PCaMSCs cells significantly inhibited MSCs-induced stemness and tumorigenesis in vitro and in vivo. Conclusions Our results reveal a novel interaction between MSCs and PCa cells in promoting tumorigenesis through activation of the Jagged1/Notch1 pathway, providing a new therapeutic target for the treatment of PCa.

scholarly journals Inhibition of MCF-7 breast cancer cell proliferation by 5alpha-dihydrotestosterone; a role for p21(Cip1/Waf1)

2004 ◽  
Vol 32 (3) ◽  
pp. 793-810 ◽  
Author(s):  
MA Greeve ◽  
RK Allan ◽  
JM Harvey ◽  
JM Bentel
Keyword(s):  
Breast Cancer ◽  
Cell Proliferation ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
S Phase ◽  
Cyclin D3 ◽  
P27 Kip1 ◽  
Mcf 7

Androgens inhibit the growth of breast cancer cells in vitro and in vivo by mechanisms that remain poorly defined. In this study, treatment of asynchronously growing MCF-7 breast cancer cells with the androgen, 5alpha-dihydrotestosterone (DHT), was shown to inhibit cell proliferation and induce moderate increases in the proportion of G1 phase cells. Consistent with targeting the G1-S phase transition, DHT pretreatment of MCF-7 cultures impeded the serum-induced progression of G1-arrested cells into S phase and reduced the kinase activities of cyclin-dependent kinase (Cdk)4 and Cdk2 to less than 50% of controls within 3 days. DHT treatment was associated with greater than twofold increases in the levels of the Cdk inhibitor, p27(Kip1), while p21(Cip1/Waf1) protein levels remained unchanged. During the first 24 h of DHT treatment, levels of Cdk4-associated p21(Cip1/Waf1) and p27(Kip1) were reduced coinciding with decreased levels of Cdk4-associated cyclin D3. In contrast, DHT treatment caused increased accumulation of Cdk2-associated p21(Cip1/Waf1), with no significant alterations in levels of p27(Kip1) bound to Cdk2 complexes. These findings suggest that DHT reverses the Cdk4-mediated titration of p21(Cip1/Waf1) and p27(Kip1) away from Cdk2 complexes, and that the increased association of p21(Cip1/Waf1) with Cdk2 complexes in part mediates the androgen-induced growth inhibition of breast cancer cells.

scholarly journals Purinergic Modulation of Interleukin-1β Release from Microglial Cells Stimulated with Bacterial Endotoxin

1997 ◽  
Vol 185 (3) ◽  
pp. 579-582 ◽  
Author(s):  
Davide Ferrari ◽  
Paola Chiozzi ◽  
Simonetta Falzoni ◽  
Stefania Hanau ◽  
Francesco Di  Virgilio
Keyword(s):  
Plasma Membrane ◽  
P2x7 Receptor ◽  
Purinergic Receptor ◽  
Present Report ◽  
Physiological Role ◽  
Bacterial Endotoxin ◽  
Microglial Cells

Microglial cells express a peculiar plasma membrane receptor for extracellular ATP, named P2Z/P2X7 purinergic receptor, that triggers massive transmembrane ion fluxes and a reversible permeabilization of the plasma membrane to hydrophylic molecules of up to 900 dalton molecule weight and eventual cell death (Di Virgilio, F. 1995. Immunol. Today. 16:524–528). The physiological role of this newly cloned (Surprenant, A., F. Rassendren, E. Kawashima, R.A. North and G. Buell. 1996. Science (Wash. DC). 272:735–737) cytolytic receptor is unknown. In vitro and in vivo activation of the macrophage and microglial cell P2Z/P2X7 receptor by exogenous ATP causes a large and rapid release of mature IL-1β. In the present report we investigated the role of microglial P2Z/P2X7 receptor in IL-1β release triggered by LPS. Our data suggest that LPS-dependent IL-1β release involves activation of this purinergic receptor as it is inhibited by the selective P2Z/P2X7 blocker oxidized ATP and modulated by ATP-hydrolyzing enzymes such as apyrase or hexokinase. Furthermore, microglial cells release ATP when stimulated with LPS. LPS-dependent release of ATP is also observed in monocyte-derived human macrophages. It is suggested that bacterial endotoxin activates an autocrine/paracrine loop that drives ATP-dependent IL-1β secretion.

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