Physiology of Pregnancy

2021 ◽  
pp. 24-59
Keyword(s):  
Bone Marrow ◽  
Ovarian Hormones ◽  
Egg Cell ◽  
Physiological Changes ◽  
Growth And Survival ◽  
Fetal Health ◽  
Multiple Organs ◽  
Pregnant State ◽  
And Shifts ◽  
Fertilized Egg

Pregnancy is associated with profound anatomical, physiological, biochemical, and endocrine changes that affect multiple organs and systems. One fertilized egg cell implanted in the lining of uterus initiates countless bodily changes. Secretion of ovarian hormones increases greatly. The bone marrow produces more RBCs and blood volume increases. The heart enlarges slightly to handle an extra supply of blood and shifts its position as uterus enlarges with the growing fetus. Such changes are necessary to help women adapt to the pregnant state and to support the growth and survival of the fetus. Such anatomical and physiological changes can also create confusion during a pregnant woman's clinical review. Likewise, changes in the biochemistry of blood during pregnancy may cause difficulties in interpreting tests. Hence, there is need to understand the deviation from normal anatomical, physiological, biochemical, and endocrine changes occurring during pregnancy so as to plan appropriate strategies for better maternal and fetal health.

Advances in the study of egg activation of higher plants

Zygote ◽  
2018 ◽  
Vol 26 (6) ◽  
pp. 435-442 ◽  
Author(s):  
Li Peng ◽  
Zhen Kai Li ◽  
Xiao Li Ding ◽  
Hui Qiao Tian
Keyword(s):  
Cell Wall ◽  
Higher Plants ◽  
Egg Activation ◽  
Sperm Cells ◽  
Physiological Changes ◽  
Cell Wall Formation ◽  
Cell Shrinkage ◽  
Functional Relevance ◽  
Polarity Change ◽  
Fertilized Egg

SummaryFertilization in higher plants induces many structural and physiological changes in the fertilized egg, and represents the transition from the haploid female gamete to the diploid zygote, the first cell of a sporophyte. Some changes are induced extremely rapidly following fusion with sperm cells and are the preclusions of egg activation. This review focuses on the early changes that occur in the egg after fusion with sperm cells, but before nuclear fusion. Reported changes include cell shrinkage, cell wall formation, polarity change, oscillation in Ca2+ concentration, and DNA synthesis. In addition, the current understanding of egg activation is summarized and the possible functional relevance of the changes is explored.

scholarly journals BRAFV600E-Positive Precursors As Molecular Markers of Bone Marrow Involvement in Pediatric Langerhans Cell Histiocytosis

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3588-3588
Author(s):  
Ko Kudo ◽  
Rika Kanezaki ◽  
Akie Kobayashi ◽  
Tomohiko Sato ◽  
Takuya Kamio ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Somatic Mutations ◽  
Bone Marrow Involvement ◽  
Braf V600e ◽  
Sensitive Assay ◽  
System Disease ◽  
Multiple Organs ◽  
Formalin Fixed Paraffin ◽  
Formalin Fixed Paraffin Embedded ◽  
Formalin Fixed

Introduction: The BRAF mutation V600E, the most common somatic mutation in Langerhans cell histiocytosis (LCH), has been reported in approximately 50% of LCH patients and is associated with certain high-risk clinical features. Precursors harboring this mutation can differentiate into Langerhans cells resulting in infiltrates in multiple organs under inflammatory conditions. However, BRAF status in the bone marrow of pediatric LCH patients is unclear. The present study examined somatic mutations in paired tumor and bone marrow samples, using a highly sensitive assay involving next-generation targeted sequencing and droplet digital polymerase chain reaction (PCR) for pediatric LCH patients. Methods: Between 1996 and 2019, in total of 17 Japanese pediatric patients with LCH were enrolled. The male/female ratio was 7/11. Ages of onset of LCH were median 13 months (range 5-193 months). At diagnosis of LCH, 2 patients were positive for risk organ involvement, 15 were negative. We retrospectively performed mutational analyses of 17 LCH cases using formalin-fixed paraffin-embedded LCH tumor specimens to provide templates for PCR-based targeted amplicon sequencing with customized primers to detect mutations in exons 12 and 15 in BRAF, and exons 2 and 3 in MAP2K1. Thereafter, we identified somatic mutations in the 17 paired bone marrow samples via droplet digital allele-specific PCR, targeting BRAF V600E and BRAF exon 12 in-frame deletion 496-500 (Ex12 in-del). Results: We detected BRAF V600E in 11 of 17 tumor samples (65%) and the BRAF Ex 12 in-del in 3 of 17 tumors (18%). We identified BRAF V600E in bone marrow samples in 10 of the 11 cases (90%) with the mutation in the tumor at low variant allele frequency (median 0.25%, range 0.14-7.0%). BRAF Ex 12 in-del was not detected in the bone marrow. Cases with detectable bone marrow involvement included eight patients with multi-system disease affecting multiple organs, one patient with multi-focal bone disease, and one patient with single-system disease. Clinical phenotypes including relapse did not correlate with BRAF V600E upon detection in the bone marrow. Conclusion: We established the sensitive assay based on PCR-based targeted NGS for detecting somatic mutations in LCH even accessible for formalin-fixed, paraffin-embedded clinical specimens. Bone marrow involvement is frequently detectable at the molecular level in pediatric LCH with the BRAF V600E mutation. A prospective study is warranted to evaluate the clinical impact of mutational burden in bone marrow. Disclosures Kudo: Unum Therapeutics: Patents & Royalties. Imai:Juno Therapeutics: Patents & Royalties.

scholarly journals Quantification of plasma cell dynamics using mathematical modelling

2018 ◽  
Vol 5 (1) ◽  
pp. 170759 ◽  
Author(s):  
Marcel Mohr ◽  
Dirk Hose ◽  
Anja Seckinger ◽  
Anna Marciniak-Czochra
Keyword(s):  
Mathematical Model ◽  
Bone Marrow ◽  
Mathematical Modelling ◽  
Plasma Cells ◽  
Cell Dynamics ◽  
Growth And Survival ◽  
Specific Antibodies ◽  
Health And Disease ◽  
Potential Basis ◽  
The Impact

Plasma cells (PCs) are the main antibody-producing cells in humans. They are long-lived so that specific antibodies against either pathogens or vaccines are produced for decades. PC longevity is attributed to specific areas within the bone marrow micro-environment, the so-called ‘niche’, providing the cells with required growth and survival factors. With antigen encounters, e.g. infection or vaccination, new PCs are generated and home to the bone marrow where they compete with resident PCs for the niche. We propose a parametrized mathematical model describing healthy PC dynamics in the bone marrow. The model accounts for competition for the niche between newly produced PCs owing to vaccination and resident PCs. Mathematical analysis and numerical simulations of the model allow explanation of the recovery of PC homoeostasis after a vaccine-induced perturbation, and the fraction of vaccine-specific PCs inside the niche. The model enables quantification of the niche-related dynamics of PCs, i.e. the duration of PC transition into the niche and the impact of different rates for PC transitions into and out of the niche on the observed cell dynamics. Ultimately, it provides a potential basis for further investigations in health and disease.

Bone marrow stromal cells promote growth and survival of prostate cancer cells

2007 ◽  
Vol 35 (4) ◽  
pp. 698-700 ◽  
Author(s):  
N.A. Cross ◽  
M. Papageorgiou ◽  
C.L. Eaton
Keyword(s):  
Prostate Cancer ◽  
Bone Marrow ◽  
Stromal Cells ◽  
Bone Marrow Stromal Cells ◽  
Marrow Stromal Cells ◽  
Cancer Cell Proliferation ◽  
Growth And Survival ◽  
Prostate Cancers ◽  
Necrosis Factor ◽  
Insulin Like Growth Factors

Prostate cancers frequently metastasize to the skeleton, and it has been hypothesized that this environment selectively supports the growth of these tumours. Specifically there is strong evidence that interactions between tumour cells and BMSCs (bone marrow stromal cells) play a major role in supporting prostate cancer growth and survival in bone. Here, we examine factors shown to be secreted by BMSCs, such as IGFs (insulin-like growth factors) and IL-6 (interleukin 6), shown to promote prostate cancer cell proliferation and to potentially replace the requirement for androgens. In addition we discuss another factor produced by BMSCs, osteoprotegerin, which may promote tumour cell survival by suppressing the biological activity of the pro-apoptotic ligand TRAIL (tumour-necrosis-factor-related apoptosis-inducing ligand).

The Role of B Cell-Activating Factor (BAFF) in the Biology of Multiple Myeloma (MM).

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 3380-3380 ◽  
Author(s):  
Noopur Raje ◽  
Shaji Kumar ◽  
Teru Hideshima ◽  
Kenji Ishitsuka ◽  
Hiroshi Yasui ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Flow Cytometry ◽  
B Cell ◽  
Cell Lines ◽  
Plasma Cells ◽  
Cell Development ◽  
Newly Diagnosed ◽  
Growth And Survival ◽  
Affymetrix U133a ◽  
Apoptotic Proteins

Abstract BAFF is a member of the tumor necrosis factor (TNF) family and is critical for the maintenance and homeostasis of normal B-cell development. Importantly, BAFF promotes the generation of rapidly dividing immunoglobulin secreting plasmablasts from activated memory B cells by enhancing their survival. Given that MM is a cancer of plasma cells and that the signaling cascades implicated in receptor ligand interactions of BAFF are crucial in MM cell biology, we hypothesized that this cytokine may play a critical role in MM cell development, survival, and proliferation. We performed gene expression profiling (GEP) on CD 138+ plasma cells isolated from 90 MM patients (45 newly diagnosed and 45 relapsed) and 11 healthy controls using the Affymetrix U133A arrays. Our data demonstrates increased expression of transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI) and B-cell maturation antigen (BCMA), 2 receptors used by BAFF to exert its effects. Our data also shows an increased expression of a proliferation-inducing ligand (APRIL), another member of the TNF family with homology to BAFF. Expression levels of BAFF and BAFF-R could not be determined because of lack of these probe sets on the Affymetrix U133A arrays. GEP analysis shows increased BCMA expression (p<0.0001, student T test) on newly diagnosed and relapsed MM versus normal plasma cells. Flow cytometry on MM cell lines demonstrated a differential expression of the three receptors of BAFF, with BCMA present on most cell lines but BAFF-R expressed at low levels only on LR5 cells and DOX40 MM cells. In contrast, flow cytometry performed on MM patient cells demonstrated the presence of all 3 receptors on CD 138+ cells. ELISA assays performed on 30 MM sera demonstrated a mean BAFF level of 618 pg/ml (range: 128–2126pg/ml) versus 235pg/ml (range: 158–326pg/ml) in 7 normal donor sera. Fifty six% (17/30) of MM patients had BAFF levels in excess of the highest value noted in normals. To understand the role BAFF might play in the biology of MM, we studied the effects of recombinant BAFF (rh-BAFF) on MM cells directly and in the context of its bone marrow microenvironment. (abstract # 554746) rh-BAFF conferred a survival advantage to MM cells and protected them against dexamethasone-induced cytotoxicity. Importantly, anti-apoptotic proteins Bcl2 and Mcl-1 were upregulated, as were growth and survival signals belonging to the JAK/STAT and MAPKinase pathways. Conversely, neutralizing antibody to BAFF blocked, at least in part, blocked the upregulation of anti-apoptotic proteins with associated growth and survival, confirming that these effects were due to BAFF. Importantly, all of these signals were downregulated even in the presence of bone marrow stromal cells (BMSCs). These data therefore show a role for BAFF mediating MM cell survival and provide the framework for inhibiting BAFF, either alone or in combination with dexamethasone, to improve patient outcome in MM.

The BAFF Inhibitor AMG523 Blocks Adhesion and Survival of Human Multiple Myeloma Cells in the Bone Marrow Microenvironment: Clinical Implication.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3452-3452 ◽  
Author(s):  
Yu-Tzu Tai ◽  
Jiangchun Xu ◽  
Xian-Feng Li ◽  
Iris Breitkreutz ◽  
Klaus Podar ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Survival ◽  
Mononuclear Cells ◽  
Flow Cytometric Analysis ◽  
Inhibitory Effect ◽  
Bone Marrow Microenvironment ◽  
Minor Role ◽  
Dependent Manner ◽  
Growth And Survival

Abstract We previously identified a role of B-cell activating factor (BAFF), a member of the tumor necrosis factor superfamily, in localization and survival of MM cells in the BM microenvironment (Cancer Res2006, 66:6675–82). In the present study, we examined the potential therapeutic utility of the BAFF inhibitor, AMG523, for treating human MM using MM lines, either sensitive or resistant to conventional chemotherapy, as well as freshly isolated patient MM cells, in the presence or absence of bone marrow stromal cells (BMSCs). AMG523 induces modest cytotoxicity in MM cell lines and patient MM cells, suggesting a minor role of autocrine mechanism of BAFF for MM growth and survival. In the presence of BMSCs, AMG523 significantly decreased growth and survival in dexamethasone (Dex)-sensitive MM1S, Dex-resistant MM1R, INA6 MM cells and in patient MM cells (n=7), in a dose-dependent manner (0.1–10 μg/ml). BAFF-augmented MM adhesion to BMSCs is also blocked by AMG523 at 0.1 mg/ml in MM lines (MM1S, 28PE, INA6), as well as in freshly isolated patient MM cells (n=4). BAFF protects MM cells against dex- and lenalidomide-induced cytotoxicity; conversely, AMG523 blocks BAFF-induced protection against drug-induced apoptosis. Importantly, pretreatment of AMG523 blocks BAFF-induced activation of AKT, nuclear factor kB, and ERK in MM cells, confirming its inhibitory effect on BAFF-mediated adhesion and survival. We next asked whether AMG523 enhances Dex-, bortezomib-, Lenalidomide-induced MM cell cytotoxicity. AMG523 augments the inhibitory effect of Dex and lenalidomide in patient MM cells in the presence of BMSCs. Since osteoclasts (OCLs) secrete BAFF in the bone marrow microenvironment, we further asked whether AMG523 inhibits protection by MM-OCL interaction. OCLs were derived from peripheral blood mononuclear cells from MM patients after 2-week culture with M-CSF and RANKL, and MM cells were added in the presence or absence of AMG523. OCLs significantly increased MM cell survival, evidenced by annexin V and PI staining followed by flow cytometric analysis; conversely, AMG523 blocked MM cell survival by coculture with OCLs. Taken together, our data demonstrate that the novel therapeutic AMG523 blocks the interaction between BAFF and its receptors in human MM, thereby providing the rationale for clinical trials of AMG523 to improve patient outcome in MM.

Inhibition of ERK1/2 Activity by the MEK1/2 Inhibitor AZD6244 (ARRY-142886) Induces Human Multiple Myeloma Cell Apoptosis in the Bone Marrow Microenvironment: A New Therapeutic Strategy for MM.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3460-3460 ◽  
Author(s):  
Yu-Tzu Tai ◽  
Xian-Feng Li ◽  
Iris Breitkreutz ◽  
Weihua Song ◽  
Peter Burger ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Cell Growth ◽  
Cell Lines ◽  
Caspase 3 ◽  
Parp Cleavage ◽  
Dependent Manner ◽  
Growth And Survival ◽  
Cyclin E1 ◽  
Human Multiple Myeloma

Abstract Activation of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase (ERK1/2 MAPK) signaling pathway mediates tumor cell growth in many cancers, including human multiple myeloma (MM). Specifically, this pathway mediates MM cell growth and survival induced by cytokines/growth factors (i.e. IL-6, IGF-1, CD40, BAFF) and adhesion to bone marrow stromal cells (BMSCs), thereby conferring resistance to apoptosis in the bone marrow (BM) milieu. In this study, we therefore examined the effect of the MEK1/2 inhibitor AZD6244 (ARRY-142886), on human MM cell lines, freshly isolated patient MM cells and MM cells adhered to BMSCs. AZD6244, inhibits constitutive and cytokine (IL-6, IGF-1, CD40)-stimulated ERK1/2, but not AKT phosphorylation. Importantly, AZD6244 inhibits the proliferation and survival of human MM cell lines, regardless of sensitivity to conventional chemotherapy, as well as freshly isolated patient MM cells. AZD6244 induces apoptosis in patient MM cells even in the presence of BMSCs, as evidenced by caspase 3 activity and PARP cleavage at concentrations as low as 20 nM. AZD6244 overcomes resistance to apoptosis in MM cells conferred by IL-6 and BMSCs, and inhibits IL-6 secretion induced by MM adhesion to BMSCs. AZD6244 suppresses MM cell survival/growth signaling pathways (i.e., STAT3, Bcl-2, cyclin E1, CDK1, CDK3, CDK7, p21/Cdc42/Rac1-activated kinase 1, casein kinase 1e, IRS1, c-maf) and up-regulates proapoptotic cascades (i.e., BAX, BINP3, BIM, BAG1, caspase 3, 8, 6). AZD6244 also upregulates proteins triggering cell cycle arrest (i.e. p16INK4A, p18INK4C, p21/WAF1 [Cdkn1a], p27 [kip1], p57). In addition, AZD6244 inhibits adhesion molecule expression in MM cells (i.e. integrin a4 [VLA-4], integrin b7, ICAM-1, ICAM-2, ICAM-3, catenin a1, c-maf) associated with decreased MM adhesion to BMSCs. These pleiotropic proapoptotic, anti-survival, anti-adhesion and -cytokine secretion effects of AZD6244 abrogate BMSC-derived protection of MM cells, thereby sensitizing them to both conventional (dexamethasone) and novel (perifosine, lenalidomide, and bortezomib) therapies. In contrast, AZD6244 has minimal cytotoxicity in BMSCs and does not inhibit DNA synthesis in CD40 ligand-stimulated CD19 expressing B-cells derived from normal donors at concentrations toxic to MM cells (between 0.02–2 mM). Furthermore, AZD6244 inhibits the expression/secretion of osteoclast (OC)-activating factors (i.e., macrophage inflammatory protein (MIP)-1a, MIP-1b, IL-1b, VEGF) from MM cells. It also downregulates MM growth and survival factors (IL-6, BAFF, APRIL) in OC cultures derived from MM patient peripheral blood mononuclear cells (PBMCs). Significantly, AZD6244 inhibits OC differentiation from MM PBMCs (n=10) in a dose-dependent manner. Together these results provide the preclinical basis for clinical trials with AZD6244 (ARRY-142886) in MM.

The Serine/Threonine Kinase Pim-2 Is a Novel Anti-Apoptotic Mediator in Myeloma Cells.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 243-243
Author(s):  
Jin Asano ◽  
Masahiro Abe ◽  
Shiro Fujii ◽  
Osamu Tanaka ◽  
Ai Mihara ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Growth ◽  
Stromal Cells ◽  
Osteoblast Differentiation ◽  
Family Members ◽  
Bone Marrow Microenvironment ◽  
Serine Threonine Kinase ◽  
Growth And Survival ◽  
Threonine Kinase ◽  
Cell Growth And Survival

Abstract Myeloma (MM) cells stimulate bone resorption by enhancing osteoclast (OC) formation and suppress bone formation by inhibiting osteoblast differentiation, leading to destructive bone lesions. In these lesions, OCs and stromal cells with defective osteoblast differentiation create a microenvironment suitable for myeloma cell growth and survival (a MM niche) to protect MM cells from various apoptotic insults. IL-6 and the TNF family members BAFF and APRIL have been demonstrated to be among predominant anti-apoptotic cytokines for MM cells elaborated by the bone marrow microenvironment in MM. The serine/threonine kinase Pim-2 is a novel apoptotic inhibitor which is transcriptionally up-regulated to promote survival of hematopoietic cells in response to environmental growth factors and cytokines. Up-regulation of Pim-2 expression has also been observed in various malignancies including MM. However, the roles for Pim-2 in growth and survival of MM cells are largely unknown. In the present study we therefore investigated the regulatory mechanism for Pim-2 expression in MM cells and the impact of Pim-2 on MM cell growth and survival with special reference to the interaction between MM cells and bone marrow components. Pim-2 protein is constitutively overexpressed in the absence of IL-6 in IL-6-dependent INA-6 as well as IL-6-independent RPMI8226 and U266 MM cell lines. Addition of IL-6, BAFF and TNFalpha up-regulated Pim-2 protein expression in INA-6 and RPMI8226 cells. A JAK/STAT3 inhibitor, cucurbitacin I, suppresses Pim-2 expression induced by IL-6, indicating Pim-2 as a downstream target of a JAK/STAT3 pathway. Stromal cells and OCs are regarded as a predominant cell type in MM bone marrow microenvironment to produce IL-6 and the TNF family members BAFF and APRIL, respectively. Co-cultures with stromal cells as well as OCs enhanced Pim-2 expression in INA-6 cells, suggesting up-regulation of Pim-2 in MM cells by surrounding cells in the bone marrow. In order to clarify the roles for Pim-2 in growth and survival of MM cells we next looked at the effects of Pim-2 siRNA. Suppression of Pim-2 expression by Pim-2 siRNA partly reduced the proliferation of INA-6 cells stimulated by IL-6 as well as the co-cultures with stromal cells or OCs. Pim-2 silencing also enhanced the cytotoxic effects of dexamethason on MM cells. Interestingly, further addition of rapamycin, an inhibitor of mammalian target of rapamycin (mTOR), induces cell death in concert with Pim-2 silencing in INA-6 cells, suggesting a cooperative roles for PI3K/Akt and Pim-2-mediated pathways in growth and survival of MM cells. Furthermore, Pim-2 silencing induced the cleavage of caspase9 but not caspase8; enforced expression of Pim-2 phosphorylated the BH3 only protein Bad; Pim-2 silencing suppressed phosphorylation of Bad by IL-6. Thus, Pim-2 appears to activate the intrinsic pathway of apoptotic machinery involving Bad phosphorylation. Taken together, our results suggest that Pim-2 is an important prosurvival mediator in MM cells, and that up-regulation of its expression in MM cells by bone marrow components may at least in part contribute to resistance to spontaneous and drug-induced apoptosis in MM cells. Therefore, Pim-2 may become a target for novel therapeutic strategies against MM.

CXCR7 Regulates SDF-1 Induced Adhesion and Homing in Multiple Myeloma.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1674-1674 ◽  
Author(s):  
Nicholas Burwick ◽  
Anne-Sophie Moreau ◽  
Xiaoying Jia ◽  
Xavier Leleu ◽  
Judith Runnels ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Flow Cytometry ◽  
Cell Adhesion ◽  
Cell Lines ◽  
Cxcr4 Expression ◽  
Rt Pcr ◽  
Growth And Survival ◽  
Tumor Types

Abstract BACKGROUND: Multiple myeloma (MM) is a plasma cell malignancy that depends on interactions with the bone marrow (BM) microenvironment for growth and survival. In turn, adhesion of MM cells to the BM stroma provides a mechanism of resistance from standard chemotherapeutic agents. Recently, our lab has shown that by disrupting this adhesion using a selective CXCR4 inhibitor named AMD3100, MM cells are more sensitive to the proteasome inhibitor Bortezomib (Ghobrial lab, unpublished data). CXCR4 has been a particularly attractive target because its ligand SDF-1 is known to induce p42/44 MAPK, AKT, and the down-stream anti-apoptotic protein bad in MM cells, leading to increased MM growth and survival. Until recently, CXCR4 was thought to be a canonical receptor for the SDF-1 ligand. However, a second chemokine receptor for SDF-1 was subsequently discovered and named CXCR7. CXCR7 is a novel chemokine receptor that is important in cell adhesion, growth and survival in several tumor types. However, the role of CXCR7 in multiple myeloma (MM) has yet to be explored. Furthermore, the ability of SDF-1 ligand to regulate MM function via CXCR7 has not been studied. METHODS: The MM cell lines (U266, MM1.S, RPMI, OPM2, OPM1) were used. After informed consent was obtained, primary bone marrow samples from MM patients were collected. CD138 positive mononuclear cells were isolated by microbead selection. The expression of CXCR7 on MM cell lines and patient samples was confirmed using flow cytometry and RT-PCR analysis. For functional in vitro and ex-vivo assays, the CXCR7 selective antagonist 733 was used (ChemoCentryx Inc., Mountain View, CA). RESULTS: Here we show that CXCR7 was expressed on all tested MM cell lines and primary patient samples as demonstrated by flow cytometry and RT-PCR. Furthermore, CXCR7 was found to regulate SDF-1 induced MM cell adhesion, as demonstrated by in vitro assays using a small molecule compound specific for CXCR7 (733). The CXCR7 antagonist showed significant inhibition of adhesion of MM cell lines and patient samples to fibronectin, endothelial cells and stromal cells, with 50% reduction of adhesion at 5nM of the CXCR7 inhibitor, and with similar activity compared to 20uM of AMD3100 (CXCR4 inhibitor). However, unlike CXCR4, CXCR7 did not effect trans-well migration to SDF-1 chemokine. Interestingly, both receptors were found to be important for trans-endothelial migration of MM cells. Moreover, pre-treatment with 733 reduced homing of MM cells to the BM niche in vivo. Previous studies have failed to show signaling in response to CXCR7 in many tumor types. Here, we demonstrate that treatment with 733 inhibited SDF-1 induced pERK and pAKT, ribosomal pS6Kinase, pGSK3, pSTAT3, pFAK and pPAK signaling pathways, confirming a role for CXCR7 in facilitating SDF-1 signaling. This effect was further confirmed using immunofluorescence. To investigate whether CXCR7 and CXCR4 interact directly, we examined the effect of 733 and AMD3100 on CXCR4 expression and found that AMD3100 significantly inhibited CXCR4 expression, while 733 had no effect on CXCR4 expression, even in the presence of SDF-1. The CXCR7 inhibitor had no effect on the survival of MM cells using MTT and flow cytometry analysis, while high doses of 733 (1uM) had modest inhibition of proliferation. Interestingly, 733 prevented the growth advantage induced by 30nM SDF-1 at 24 hrs. CONCLUSION: Together, these results demonstrate the importance of CXCR7 in regulating MM adhesion and homing, and highlight the differential effects of CXCR4 and CXCR7 in regulating SDF-1 signaling in MM, thus providing a rationale for targeting the SDF-1/CXCR7 axis in MM.

Nocodazole Induces Myeloma Cell Death by Disrupting the Microtubular Network, Resulting in G2/M Arrest

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3673-3673
Author(s):  
Rentian Feng ◽  
Jorge A Rios ◽  
Markus Mapara ◽  
Suzanne Lentzsch
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Cell Death ◽  
Cell Lines ◽  
Myeloma Cell ◽  
Caspase 8 ◽  
Inhibition Rate ◽  
Growth And Survival ◽  
Microtubular Network

Abstract Patients with relapsed multiple myeloma (MM) previously treated with bortezomib and lenalidomide often fail to respond to further therapies. To identify potential new treatment approaches for MM, we used Luminex technology to screen a library of 1,120 compounds provided by the Multiple Myeloma Research Foundation. By multiplex cytokine array, we identified benzimidazoles including the anthelmintics mebendazole, fenbendazole, albendazole, nocodazole and pyrvinium pamoate, as inhibiting the production of cytokines essential for MM cell growth and survival, such as IL-6 (inhibition rate 40–70%), MIP-1α (inhibition rate 65–75%), VEGF (inhibition rate 75%), and soluble IL-6R (inhibition rate 40–52%). Consequently, these anthelmintics demonstrated dose-dependent inhibition of myeloma cell (RPMI-8226, H929, U266 and MM1S) proliferation. The lead compound, nocodazole, caused nuclear fragmentation and caspase-8 activation in MM cell lines and primary CD138+ cells in dose- and time-dependent fashion (IC50: 30–60 nM). Importantly, growth and survival signals provided by bone marrow stromal cells in bone marrow co-cultures failed to protect MM cells from nocodazole-induced cell death. In the apoptotic cells, caspase-8 was more activated than caspase-9, suggesting that mitochondrial signaling is not a major apoptotic pathway. Cell cycle analysis indicated that G2/M cell cycle arrest reached a peak at 17 hr. Sub-G1 proportion was strongly increased after treatment for 24 hr in all tested cell lines. Electron microscope (EM) and nuclear staining studies consistently showed the accumulation of metaphase cells, and morphologic elongation at 7 hr, at which time G2/M arrest was obvious. Most of the elongated cells had only one nucleus, suggesting that they failed to progress to mitosis due to overall microtubular network disarray. We conclude that nocodazole exposure induced microtubular network disarray with cell elongation, and G2/M arrest with a late stage mitotic block resulting in cell death. Benzimidazoles including nocodazole, traditionally used as antihelmintic drugs, have shown antitumor activity against hepatocellular, lung and adrenocortical carcinoma, and melanoma. In our study, we identified the anthelmintic compound nocodazole as a new anti-myeloma agent. Nocodazole warrants further investigation for its anti-MM effects in vitro and in vivo.

Sign in / Sign up

Export Citation Format

Share Document