Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Multiple myeloma (MM) remains largely incurable despite conventional and high-dose therapies. Therefore, novel biologically based treatment approaches are urgently required. Here we demonstrate that expression of peroxisome proliferator-activated receptor gamma (PPARgamma) in MM cells and its agonists 15-d-PGJ2 and troglitazone completely abolished IL-6-inducible MM cell proliferation and induced apoptosis through affecting expression of multiple cell cycle or apoptosis genes, whereas PPARgamma antagonist GW9662 and PPARalpha agonist WY14643 did not display this inhibitory effect. These PPARgamma agonists significantly inhibited DNA binding and transactivation of STAT3 bound to the promoter of target genes in chromatin, but did not affect the expression of IL-6 receptor and phosphorylation of JAK/STAT3, MAPK, and PI3K/Akt. Interestingly, although inactivation of STAT3 by PPARgamma agonists is in a PPARgamma-dependent manner, the molecular mechanism by which two structurally distinct PPARgamma agonists suppress IL-6-activated STAT3 shows the divergent interactions between PPARgamma and STAT3 including direct or SMRT-mediated association.
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PMID:Transcriptional inactivation of STAT3 by PPARgamma suppresses IL-6-responsive multiple myeloma cells. 1497 42

Lung cancer is the leading cause of cancer-related death in developed countries. Non-small cell lung cancer (NSCLC) represents 80% of the total lung cancer cases and is comprised of adenocarcinoma, adenosquamous carcinoma, squamous cell carcinoma and large cell carcinoma (LCC) subtypes. The ability of LCC to metastasize earlier than the other forms of lung cancer suggests anti-angiogenic drugs as effective agents to combat this cancer. Thalidomide is an anti-angiogenic drug that has shown promise in multiple hematological diseases, and myeloma and other cancers. However, the molecular mechanism by which thalidomide exerts its effects is poorly understood. Therefore, we evaluated the effectiveness of thalidomide on NSCLC cell growth, and found that LCC cells were growth inhibited by 40-60%. This effect seemed specific to LCC cancer cells, since other forms of NSCLC were only mildly affected by thalidomide. At the molecular level, thalidomide increased peroxisome proliferator-activated receptor gamma (PPARgamma) protein dose-dependently, and peroxisome proliferator response element activity. Further, thalidomide treatment of LCC cells decreased nuclear factor kappa B activity in a dose-dependent fashion, increased apoptosis and decreased the expression of angiogenic proteins. In our mouse xenograft model of lung cancer, we found that intratumoral thalidomide caused a 64% decrease in tumor growth; moreover, tumors from the thalidomide-treated mice expressed higher PPARgamma, than tumors from control mice. This study shows the antitumor activity of thalidomide against LCC tumors and suggests a model in which thalidomide exerts its antitumor effects on LCC cells through the induction of PPARgamma and subsequent downstream signaling. To our knowledge, this is the first study to show a link between thalidomide and PPARgamma.
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PMID:The effect of thalidomide on non-small cell lung cancer (NSCLC) cell lines: possible involvement in the PPARgamma pathway. 1520 58

Multiple myeloma is essentially an incurable malignancy and it is therefore of great interest to develop new therapeutic approaches. We previously reported that human B cell-lymphomas express the nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) and are killed by PPARgamma ligands. Herein, we investigate the therapeutic potential of PPARgamma ligands for multiple myeloma. The human multiple myeloma cell lines ANBL6 and 8226 express PPARgamma mRNA and protein. The PPARgamma ligands, 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) and ciglitazone, induced multiple myeloma cell apoptosis as determined by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay, loss of mitochondrial membrane potential, and caspase activation. Importantly, the ability of PPARgamma ligands to kill both multiple myeloma cell lines was not abrogated by Interleukin-6 (IL-6), a multiple myeloma growth survival factor. Finally, the RXR ligand 9-cis retinoic acid (9-cis RA) in combination with PPARgamma ligands greatly enhanced multiple myeloma cell killing. These new findings support that PPARgamma ligands may represent a novel therapy for multiple myeloma.
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PMID:Human multiple myeloma cells express peroxisome proliferator-activated receptor gamma and undergo apoptosis upon exposure to PPARgamma ligands. 1545 78

The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a member of the nuclear receptor family that forms heterodimers with retinoid X receptor. These heterodimers bind to DNA and activate the transcription of target genes. Here, we report that the PPAR gamma receptor protein is expressed in primary myeloid and lymphoid leukemias and in lymphoma and myeloma cell lines. In this study, we compared the activity of several PPAR gamma ligands including BRL49653 (rosiglitazone), 15-deoxy-Delta 12,14-prostaglandin J(2), and the novel triterpenoid 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid on leukemia cells. Exposure to these PPAR gamma ligands induced apoptosis in myeloid (U937 and HL-60) and lymphoid (Su-DHL, Sup-M2, Ramos, Raji, Hodgkin's cell lines, and primary chronic lymphocytic leukemia) cells. A similar exposure to these PPAR gamma ligands induced the differentiation of myeloid leukemic cells. A combination of PPAR gamma ligands with a retinoid X receptor agonist (i.e., LG100268) or a retinoic acid receptor agonist (i.e., all trans-retinoic acid) enhanced differentiating and growth-inhibitory effects. 2-Cyano-3,12-dioxooleana-1,9-dien-28-oic acid induced differentiation and apoptosis with much greater potency than the other PPAR gamma ligands in established cell lines and primary chronic lymphocytic leukemia samples. Exposure to 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid induced mitochondrial depolarization and caspase activation, which was associated with apoptosis induction. In Bcl-2-overexpressing chronic lymphocytic leukemia cells, the small-molecule Bcl-2 inhibitor HA14-1 sensitized these cells to 2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid-induced apoptosis. These results suggest that PPAR gamma ligation alone and in combination with retinoids holds promise as novel therapy for leukemias by activating the transcriptional activity of target genes that control apoptosis and differentiation in leukemias.
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PMID:Peroxisome proliferator-activated receptor gamma and retinoid X receptor ligands are potent inducers of differentiation and apoptosis in leukemias. 1548 92

The activation of proliferator-activated receptor gamma (PPAR-gamma) by its natural and synthetic ligands induces apoptosis in several tumor cell lines, including malignant B-lineage cells. We investigated whether treatment with pioglitazone (PGZ), rosiglitazone (RGZ) or 15-deoxy-Delta12,14-prostaglandin J2 (15d-PGJ2) inhibited tumor cell growth in five human multiple myeloma cell lines (LP-1, U-266, RPMI-8226-S, OPM-2 and IM-9) and human bone marrow myeloma cells expressing PPAR-gamma protein. MTT assays revealed growth arrest induced by the natural activator of PPAR-gamma 15d-PGJ2 and a lower antiproliferative effect with thiazolidinediones (PGZ and RGZ) in a dose-dependent manner. Induction of apoptosis was indicated by Annexin-V staining. At a dose of 50 microM, 15d-PGJ2 led to a high rate of apoptosis in all cell lines (60-92%). Furthermore, induction of apoptosis in sorted bone marrow plasma cells from myeloma patients was detected. Thiazolidinediones comprise anti-myeloma activity in vitro and should be explored further for the treatment of multiple myeloma.
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PMID:Ligands of peroxisome proliferator-activated receptor gamma induce apoptosis in multiple myeloma. 1551 64

Multiple myeloma (MM) remains largely incurable despite conventional and high-dose therapies. Therefore, novel biologically based treatment approaches are urgently required. Particularly, STAT3 activated by IL-6 has a key role in preventing apoptosis and stimulating growth of multiple myeloma cells. Nuclear receptors, a distinct class of ligand-activated transcriptional factors, can interact and modify the function of transcriptional factors intrinsic to the cytokine signal transduction pathways. We have investigated regulation of two nuclear receptors, peroxisome proliferator-activated receptor gamma (PPARgamma) and estrogen receptor (ER), and their crosstalk with STAT3 in multiple myeloma. These results indicate that ligand-activated nuclear receptors can function as negative modulators of STAT3 through direct mechanisms, or in turn, by facilitating coregulators such as PIAS or SMRT. Therefore, different classes of nuclear receptors affect suppression of STAT3 functions through diverse mechanisms resulting in downregulating IL-6-mediated cell growth and gene expression. Given the importance of IL-6 in multiple myeloma, the estrogen receptor-STAT3 or PPARgamma-STAT3 interaction may have significant therapeutic implications in multiple myeloma.
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PMID:Nuclear receptors as negative modulators of STAT3 in multiple myeloma. 1565 77

The serum levels of an adrenal sex hormone, dehydroepiandrosterone sulfate (DHEA-S), are significantly more decreased in human myelomas compared with the reduction brought by physiologic decline with age. In order to clarify the effect of DHEA on myeloma cells, we investigated whether DHEA and DHEA-S could inhibit interleukin-6 (IL-6) production of bone marrow mononuclear cells and the proliferation of myeloma cells from patients with myeloma. DHEA-S and DHEA suppressed IL-6 production from a bone marrow stromal cell line, KM-102, as well as in bone marrow mononuclear cells from patients with myeloma. Furthermore, DHEA inhibited in vitro growth of the U-266 cell line and primary myeloma cells from the patients, as well as the in vivo growth of U-266 cells implanted i.p. in severe combined immunodeficiency-hIL6 transgenic mice. DHEA up-regulated the expression of peroxisome proliferator-activated receptor (PPAR), PPAR beta, but not PPARgamma or PPARalpha, and the expression of IkappaBalpha gene in myeloma cells and bone marrow stromal cells, which could explain the suppressive effect of DHEA on IL-6 production through the down-regulation of NF-kappaB activity. Therefore, these data revealed that DHEA-S, as well as DHEA, had a direct effect on myeloma and bone marrow stromal cells to inhibit their proliferation and IL-6 production, respectively.
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PMID:Dehydroepiandrosterone can inhibit the proliferation of myeloma cells and the interleukin-6 production of bone marrow mononuclear cells from patients with myeloma. 1578 40

Binding of multiple myeloma (MM) cells to bone marrow stromal cells (BMSCs) triggers expression of adhesive molecules and secretion of interleukin-6 (IL-6), promoting MM cell growth, survival, drug resistance, and migration, which highlights the possibility of developing and validating novel anti-MM therapeutic strategies targeting MM cells-host BMSC interactions and their sequelae. Recently, we have found that expression of the peroxisome proliferator-activated receptor gamma (PPARgamma) and its ligands can potently inhibit IL-6-regulated MM cell growth. Here we demonstrate that PPARgamma agonists 15-d-PGJ2 and troglitazone significantly suppress cell-cell adhesive events, including expression of adhesion molecules and IL-6 secretion from BMSCs triggered by adhesion of MM cells, as well as overcome drug resistance by a PPARgamma-dependent mechanism. The synthetic and natural PPARgamma agonists have diverging and overlapping mechanisms blocking transactivation of transcription factors NF-kappaB and 5'-CCAAT/enhancer-binding protein beta (C/EBPbeta). Both 15-d-PGJ2 and troglitazone blocked C/EBPbeta transcriptional activity by forming PPARgamma complexes with C/EBPbeta. 15-d-PGJ2 and troglitazone also blocked NF-kappaB activation by recruiting the coactivator PGC-1 from p65/p50 complexes. In addition, 15-d-PGJ2 had a non-PPARgamma-dependent effect by inactivation of phosphorylation of IKK and IkappaB. These studies provide the framework for PPARgamma-based pharmacological strategies targeting adhesive interactions of MM cells with the bone marrow microenvironment.
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PMID:Inhibition of adhesive interaction between multiple myeloma and bone marrow stromal cells by PPARgamma cross talk with NF-kappaB and C/EBP. 1778 86

Mycophenolic acid (MPA, 1), an inhibitor of IMP-dehydrogenase (IMPDH) and a latent PPARgamma agonist, is used as an effective immunosuppressant for clinical transplantation and recently entered clinical trials in advanced multiple myeloma patients. On the other hand, suberoylanilide hydroxamic acid (SAHA), a non-specific histone deacetylase (HDAC) inhibitor, has been approved for treating cutaneous T-cell lymphoma. MPA seemed to bear a cap, a linker, and a weak metal-binding site as a latent inhibitor of HDAC. Therefore, the hydroxamic acid derivatives of mycophenolic acid having an effective metal-binding site, mycophenolic hydroxamic acid (MPHA, 2), 7-O-acetyl mycophenolic acid (7-O-Ac MPHA, 3), and 7-O-lauroyl mycophenolic hydroxamic acid (7-O-L MPHA, 4) were designed and synthesized. All these compounds inhibited histone deacetylase with IC50 values of 1, 0.9 and 0.5 microM, and cell proliferation at concentrations of 2, 1.5 and 1 microM, respectively.
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PMID:Hydroxamic acid derivatives of mycophenolic acid inhibit histone deacetylase at the cellular level. 1883 93

Activation of PPARgamma by its ligands has shown differentiating effects in solid tumors. However, few reports addressed its role in myeloma cells. Our study demonstrated that exposure to PPARgamma ligand (rosiglitazone, RGZ) induced proliferation inhibition and cell cycle arrest in myeloma cells. A combination of RGZ with all-trans retinoic acid (ATRA) can enhance the growth inhibition effects of RGZ. Further study shows that RGZ-treated myeloma cells displayed morphological characteristics of cell differentiation, and more evident signs of differentiation were observed when RGZ was combined with ATRA. These changes were confirmed by the detection of CD49e expression and light chain protein secretion. Similar results were also observed when primary CD138(+) cells were treated with RGZ and ATRA. Collectively, our study revealed that RGZ can induce cell differentiation in myeloma cells and concomitant treatment with ATRA can enhanced the effects of RGZ.
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PMID:Multiple myeloma cells undergo differentiation upon exposure to rosiglitazone and all-trans retinoic acid. 2485 Jan 42


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