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M Jourdan

Publications and source records attributed to M Jourdan.

At least 37 records · Page 2Linked to original sources
PubMed1999

Tumor necrosis factor is a survival and proliferation factor for human myeloma cells.

Interleukin-6 (IL-6) is a major survival factor for malignant plasma cells. In patients with multiple myeloma (MM), cell lines whose survival and proliferation are dependent upon addition of exogenous IL-6 have been obtained. We show here that tumor necrosis factor-alpha (TNF-alpha) is also a survival factor for myeloma cell lines, although less potent than IL-6. The survival activity of TNF-alpha is not affected by anti-IL-6 or anti-gp130 monoclonal antibodies (mAbs). TNF-alpha also induces myeloma cells in the cell cycle and promotes the long-term growth of malignant plasma cell lines. As TNF-alpha is produced in patients with MM and associated with a poor prognosis, these results suggest that anti-TNF-alpha therapies could be useful in this disease.

Antibodies, Monoclonal↗
PubMed1998

IFN-alpha is a survival factor for human myeloma cells and reduces dexamethasone-induced apoptosis.

IFN-alpha is used as a maintenance therapy in patients with multiple myeloma, but its benefit is a matter of controversy. In vitro studies show that IFN-alpha can both stimulate and inhibit myeloma cell proliferation. We have tested the effect of IFN-alpha on the survival of myeloma cell lines and primary plasma cells. IFN-alpha significantly reduced the apoptosis induced by removal of IL-6 in four IL-6-dependent myeloma cell lines. It also reduced the level of apoptosis induced by dexamethasone in these cell lines as well as in purified primary myeloma cells from seven patients. IFN-alpha promoted the survival of myeloma cells, which, following removal of IL-6, were blocked in G1 and died. However, unlike IL-6, IFN-alpha-treated cells remained mainly blocked in the G1 phase of the cycle. While the effects of IL-6 are mediated through stimulation of its gp130 receptor subunit, the IFN-alpha-induced survival of myeloma cells was independent of gp130 transducer activation (as demonstrated using a neutralizing anti-gp130 Ab). However, the signal transduction cascades activated by these two cytokines share at least some common elements, since stimulation with either IFN-alpha or IL-6 resulted in STAT3 phosphorylation. These results indicate that IFN-alpha promotes the survival, but not the proliferation, of myeloma cells, preventing the apoptosis induced by removal of IL-6 or addition of dexamethasone. This survival factor activity may explain the conflicting reports on the effects of IFN-alpha on myeloma cell proliferation.

Antigens, CD↗
PubMed1998

The myeloma cell antigen syndecan-1 is lost by apoptotic myeloma cells.

Syndecan-1 is a cell membrane proteoglycan that binds extracellular matrix components and various growth factors. It is expressed only on malignant plasma cells in bone marrow samples from patients with multiple myeloma (MM). Several reports have suggested that syndecan-1 was present only on a part of the myeloma cells. By using either IL-6-dependent myeloma cell lines or primary myeloma cells stained by annexin V, we report here that syndecan-1 was rapidly lost by myeloma cells undergoing apoptosis. In the same experimental conditions, expression of other cell membrane antigens such as CD38, HLA class-I or CD49d on apoptotic myeloma cells was not affected. In addition, we show that syndecan-1 loss was independent of activation of the gp130 IL-6 transducer. Dexamethasone induced a strong apoptosis of myeloma cells associated with the loss of syndecan-1. Finally, by using freshly-explanted tumoural samples, we show that syndecan-1 rapidly disappeared from myeloma cells in association with induction of apoptosis. In conclusion we showed that syndecan-1 is a marker for viable myeloma cells which is rapidly lost by apoptotic cells. These results emphasize the usefulness of anti-syndecan-1 antibodies to purge tumoural cells from haemopoietic grafts or to purify these cells for further manipulations for immuno or gene therapies.

ADP-ribosyl Cyclase↗
PubMed1996

Intrinsic B cell defects in NZB and NZW mice contribute to systemic lupus erythematosus in (NZB x NZW)F1 mice.

We have previously shown that long-term in vitro proliferating fetal liver pre-B cell lines derived from autoimmune-prone (NZB x NZW)F1 (BW) mice, but not normal (B6 x DBA2)F1 mice, can differentiate in severe combined immunodeficient (SCID) mice to produce elevated levels of serum immunoglobulin (Ig) M and IgG, and high titers of antinuclear antibodies The contribution of parental NZB and NZW strains to B cell abnormalities of BW hybrid mice was investigated here by preparing pre-B cells and transferring them into immunodeficient SCID- and RAG-2-targeted mice. We show that transfer of NZB pre-B cells led to a marked IgM hypergammaglobulinemia and to the production of limited amounts of IgG2a. On the other hand, the transfer of NZW pre-B cell lines led to moderately elevated IgM levels and marked hypergammaglobulinemia of IgG2a. High IgM and low IgG anti-DNA titers are found in the recipients of NZB pre-B cells, whereas those receiving NZW pre-B cells contained lower levels of IgM and high titers of IgG anti-DNA. In marked contrast, essentially identical titers of antibodies directed against a non-self-antigen, DNP, are found in all group of pre-B cell recipients. Thus, B-lineage cells of both NZB and NZW parental strains manifest abnormalities associated with the development of this lupus-like disease. Therefore, the present study strongly suggests a complex inheritance of B cell abnormalities in autoimmune-prone (NZB x NZW)F1 mice and emphasizes the critical importance of intrinsic B cell defects in the development of murine systemic lupus erythematosus.

Animals↗
PubMed1995

Investigation of the complement receptor 3 (CD11b/CD18) in human rectal epithelium.

Rectal and cervicovaginal mucosa are common routes of transmission of HIV, although the mechanism of transmission is unknown. We have investigated human rectal and cervicovaginal epithelia for the expression of complement receptors (CR) and cell adhesion molecules which may be involved in HIV and other infections. In rectal mucosa, CR3 was detected in the surface and crypt epithelial cells by immunohistology, using MoAbs to CD18 and CD11b in 10 out of 15 specimens. RNA transcripts encoding both CD11b and CD18 were also demonstrated in surface and crypt epithelial cells by in situ hybridization. Although CD11b was detected in the epithelial cells in three out of the 14 cervicovaginal specimens, we were unable to detect CD18. We suggest that expression of the CD11b/CD18 heterodimer might facilitate transmission of HIV by enhancing binding of HIV-antibody complexes in seminal fluid to epithelial cells. Alternatively, since intercellular adhesion molecule-1 (ICAM-1) is a receptor for CD11b/CD18, this may promote adhesion between epithelial cells and HIV-infected mononuclear cells in seminal fluid.

CD18 Antigens↗
PubMed1994

Reproducible obtaining of human myeloma cell lines as a model for tumor stem cell study in human multiple myeloma.

We report a novel, reproducible methodology which enabled 10 human myeloma cell lines (HMCL) to be obtained from each of 10 tumor samples harvested from 9 patients with extramedullary proliferation. Fresh samples were cultured with interleukin 6 (IL-6) and granulocyte macrophage-colony stimulating factor (GM-CSF) at a high cell density and resulting HMCL growth became progressively dependent on IL-6 alone, no longer requiring GM-CSF. These HMCL, which had the same immunoglobulin gene rearrangements as the patients' original myeloma cells, were designated XG-1 to XG-9. XG HMCL had a plasma cell morphology, expressed plasma cell antigen (Ag), namely cytoplasmic immunoglobulins, CD38, B-B4 Ag, and CD77, and lacked the usual B-cell Ag. They also expressed activation antigens such as CD28 with coexpression of CD28 and its ligand, B7 Ag, in four HMCL. Six HMCL expressed CD40, 4 CD23, and 5 its ligand, CD21. The XG HMCL bore adhesion molecules VLA-4 and CD44 (all 10 HMCL), VLA-5 (7 HMCL), and CD56 (4 HMCL). Finally, cytogenetic study of 8 HMCL indicated a 14q+ chromosome, and t(11,14) translocation was found in 6 of 8 and 5 of 8 HMCL, respectively. The possibility of obtaining malignant plasma cell lines reproducibly from each patient with extramedullary proliferation offers a unique tool for studying the phenotype and abnormalities of the still unidentified tumor stem cell in this disease.

Cell Division↗
PubMed1993

Cytokine gene expression in human multiple myeloma.

In the present study the gene expression of cytokines promoting in vitro myeloma-cell growth was investigated by Northern blot analysis using total RNA of 36 tumour samples of patients with multiple myeloma (MM) or plasma cell leukaemia and poly(A)+ RNA of 10 human myeloma cell lines (HMCL). These cytokines included interleukin (IL)-1 alpha, IL-1 beta, IL-3, IL-6, granulocyte-macrophage (GM)-colony-stimulating factor (CSF) and granulocyte (G)-CSF. IL-1 beta, IL-6 and G-CSF genes were coexpressed in most patients, although at variable levels. IL-1 alpha transcripts were detected in 32% of patients in whom coexpression of IL-1 beta gene was found. IL-3 gene was not expressed in patients' cells and GM-CSF mRNA was detected in only 1/32 patients. No detectable transcripts for the above cytokines were present in HMCL, whereas IL-6 gene was expressed in 2/10 HMCL. We also looked for the presence of transcripts for IL-2, leukaemia inhibitory factor (LIF) and transforming growth factor (TGF)beta in cells of tumour samples from the same patients and in HMCL. IL-2 gene was not expressed in MM patients and HMCL. Weak expression of LIF gene was detected in three patients (9%), and transforming growth factor beta (TGF beta) mRNA was observed in 12/12 tumour samples analysed and all HMCL. These results suggest that, among cytokines shown to control myeloma-cell growth in vitro, IL-1, IL-6 and G-CSF could play a role in the development of myeloma disease in vivo.

Blotting, Northern↗
PubMed1992

Up-regulation of interleukin (IL)-6 receptor gene expression in vitro and in vivo in IL-6 deprived myeloma cells.

Myeloma cells absolutely require interleukin-6 (IL-6) for growing in vivo in patients with multiple myeloma and exogenous IL-6-dependent myeloma cell lines have been reproducibly obtained. In this study we show a dramatic up-regulation of the IL-6 receptor (gp80 chain) gene expression in myeloma cell lines following the removal of exogenous IL-6. Such a regulation was also known to occur in IL-6-deprived myeloma cells in vivo in three patients who were treated with optimal doses of anti-IL-6 monoclonal antibodies. The direct effect of IL-6 on IL-6 receptor gene expression in myeloma cells was further confirmed by adding IL-6 to an autonomously growing myeloma cell line.

Blotting, Northern↗
PubMed1992

Complete nucleotide sequence of the cloned infectious genome of Junonia coenia densovirus reveals an organization unique among parvoviruses.

We previously constructed a recombinant plasmid, pBRJ, encompassing an infectious Junonia coenia densovirus (JcDNV) genome (M. Jourdan et al. (1990). Virology 179, 403-409). We report here the complete viral sequence of pBRJ. The genome, 5908 nucleotides (nt) long, consists of an internal unique sequence flanked by long (517 nt) inverted terminal repeats. The first 96 bases of one extremity can fold into a typical Y-shaped hairpin structure. The opposite extremity is incomplete, lacking 88 nt. These terminal structures, similar to those of dependoviruses, human parvovirus B19 and Bombyx mori densovirus (BmDNV), strongly suggest a common mechanism of DNA replication for these parvoviruses. JcDNV genomic organization is unique among parvoviruses in that coding sequences are evenly distributed in the 5' half of both strands. On one strand, the major open reading frame (ORF1) encodes the four structural proteins. On the complementary strand, ORF2, ORF3 (included in ORF2), and ORF4 probably encode nonstructural proteins. JcDNV genome has little DNA homology with vertebrate parvoviruses and surprisingly even less with the two densoviruses presently sequenced. ORF1 contains the highly conserved PGY and G-rich regions and ORF2 the NTP-binding domain common to most structural and to all nonstructural vertebrate parvoviral ORFs, respectively. The single homology between JcDNV and BmDNV is unexpectedly located in JcDNV NTP-binding domain and BmDNV ORF2 assumed to encode structural polypeptides. Only a weak homology exists between JcDNV and Aedes DNV in their NTP-binding domain.

Amino Acid Sequence↗
PubMed1992

Mutations of the p53 gene in human myeloma cell lines.

Mutations affecting the p53 gene have been found associated with many human malignancies, but little is as yet known about multiple myeloma. We investigated p53 gene alterations in 10 human myeloma cell lines (HMCL), half of these being dependent upon exogenous interleukin 6 (IL-6) for in vitro growth, similar to freshly explanted myeloma cells. Using a polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) approach, eight of the 10 HMCL were found to bear a mutated p53 gene. All the mutations were single base substitutions with a predominance of G:C to A:T transitions. There was no apparent relation between the presence of a mutation and IL-6 requirement of the cell line. Interestingly, in two cell lines (XG-2 and XG-4) the SSCP pattern showed the presence of both the wild-type and the mutated allele and, upon reverse PCR on RNA, both alleles were found to be concomitantly expressed at the RNA level. Moreover, three freshly explanted tumor samples had the same p53 gene status (mutated versus wild type) as the HMCL that were derived from them. These results show that p53 mutations are frequent in HMCL. Although no apparent relation could be evidenced with the loss of exogenous IL-6 requirement, it may prove interesting to investigate further potential relations between the presence of a mutated p53 allele and gradual autonomy for cell growth.

Base Sequence↗