scholarly journals Interleukin-6 Overcomes p21WAF1 Upregulation and G1 Growth Arrest Induced by Dexamethasone and Interferon-γ in Multiple Myeloma Cells

Blood ◽  
1997 ◽  
Vol 90 (1) ◽  
pp. 279-289 ◽  
Author(s):  
Mitsuyoshi Urashima ◽  
Gerrard Teoh ◽  
Dharminder Chauhan ◽  
Yasutaka Hoshi ◽  
Atsushi Ogata ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Protein Expression ◽  
Interleukin 6 ◽  
Present Report ◽  
Growth Arrest ◽  
Interferon Γ ◽  
Cell Cycle Distribution ◽  
P21 Protein ◽  
Ifn Γ

Abstract Interleukin-6 (IL-6) is a growth factor for multiple myeloma (MM) cells and can inhibit MM cell apoptosis. Our recent studies show that IL-6 facilitates MM cell growth via phosphorylation of retinoblastoma protein (pRB); however, the effects of IL-6 on those cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors (CDIs) that are known to regulate phosphorylation of pRB have not been defined in MM cells. In the present report, we cultured MM cell lines and patient cells with IL-6 and/or dexamethasone (Dex) and characterized changes in cell cycle; expression and association of cyclins, CDKs, and CDIs; and phosphorylation of pRB. Dex induced G1 growth arrest in MM cells, whereas IL-6 facilitated G1 to S phase transition; moreover, the effect of Dex was blocked by IL-6. p21WAF1 (p21) protein was constitutively expressed in the majority of MM cells independent of the status of p53. Its expression was upregulated by Dex and downregulated by IL-6; again, IL-6 inhibited the increase in p21 triggered by Dex. These alterations in p21 expression in MM cells were associated with changes in p21 binding to CDK2, CDK4, and CDK6; CDK2, CDK4, and CDK6 kinase activities; and phosphorylation of pRB. In contrast, expression of G1 cell cycle regulatory proteins, including p27KIP1, cyclin D2, and cyclin E, was not altered in MM cells cultured with Dex and/or IL-6. Finally, interferon-γ (IFN-γ) also induced G1 growth arrest and upregulated p21 protein expression; as with Dex, affects of IFN-γ were inhibited by IL-6. Our results therefore show that changes in cell cycle distribution in MM cells triggered by Dex, IL-6, and IFN-γ correlate with changes in p21 protein expression and implicate p21 in the coupling of Dex-, IL-6–, and IFN-γ–related signals to G1 cell cycle regulation in MM cells.

scholarly journals Interleukin-6 Overcomes p21WAF1 Upregulation and G1 Growth Arrest Induced by Dexamethasone and Interferon-γ in Multiple Myeloma Cells

Blood ◽  
1997 ◽  
Vol 90 (1) ◽  
pp. 279-289 ◽  
Author(s):  
Mitsuyoshi Urashima ◽  
Gerrard Teoh ◽  
Dharminder Chauhan ◽  
Yasutaka Hoshi ◽  
Atsushi Ogata ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Protein Expression ◽  
Interleukin 6 ◽  
Present Report ◽  
Growth Arrest ◽  
Interferon Γ ◽  
Cell Cycle Distribution ◽  
P21 Protein ◽  
Ifn Γ

Interleukin-6 (IL-6) is a growth factor for multiple myeloma (MM) cells and can inhibit MM cell apoptosis. Our recent studies show that IL-6 facilitates MM cell growth via phosphorylation of retinoblastoma protein (pRB); however, the effects of IL-6 on those cyclins, cyclin-dependent kinases (CDKs), and CDK inhibitors (CDIs) that are known to regulate phosphorylation of pRB have not been defined in MM cells. In the present report, we cultured MM cell lines and patient cells with IL-6 and/or dexamethasone (Dex) and characterized changes in cell cycle; expression and association of cyclins, CDKs, and CDIs; and phosphorylation of pRB. Dex induced G1 growth arrest in MM cells, whereas IL-6 facilitated G1 to S phase transition; moreover, the effect of Dex was blocked by IL-6. p21WAF1 (p21) protein was constitutively expressed in the majority of MM cells independent of the status of p53. Its expression was upregulated by Dex and downregulated by IL-6; again, IL-6 inhibited the increase in p21 triggered by Dex. These alterations in p21 expression in MM cells were associated with changes in p21 binding to CDK2, CDK4, and CDK6; CDK2, CDK4, and CDK6 kinase activities; and phosphorylation of pRB. In contrast, expression of G1 cell cycle regulatory proteins, including p27KIP1, cyclin D2, and cyclin E, was not altered in MM cells cultured with Dex and/or IL-6. Finally, interferon-γ (IFN-γ) also induced G1 growth arrest and upregulated p21 protein expression; as with Dex, affects of IFN-γ were inhibited by IL-6. Our results therefore show that changes in cell cycle distribution in MM cells triggered by Dex, IL-6, and IFN-γ correlate with changes in p21 protein expression and implicate p21 in the coupling of Dex-, IL-6–, and IFN-γ–related signals to G1 cell cycle regulation in MM cells.

Interleukin-6–Induced Inhibition of Multiple Myeloma Cell Apoptosis: Support for the Hypothesis That Protection Is Mediated Via Inhibition of the JNK/SAPK Pathway

Blood ◽  
1998 ◽  
Vol 92 (1) ◽  
pp. 241-251 ◽  
Author(s):  
Feng-hao Xu ◽  
Sanjesh Sharma ◽  
Agnes Gardner ◽  
Yiping Tu ◽  
Arthur Raitano ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Interleukin 6 ◽  
Plasma Cells ◽  
Myeloma Cell ◽  
Dominant Negative ◽  
Cell Cycle Distribution ◽  
Inhibitory Effects ◽  
Multiple Myeloma Cell ◽  
Induced Apoptosis

The mechanism by which interleukin-6 (IL-6) protects multiple myeloma (MM) plasma cells from apoptosis induced by anti-fas antibodies and dexamethasone was studied. Anti-apoptotic concentrations of IL-6 had no effect on cell-cycle distribution or activation of RAF-1 or ERK in dexamethasone- or anti–fas-treated 8226 and UCLA #1 MM cell lines. However, IL-6–dependent protection of viability correlated with an inhibition of dexamethasone- and anti–fas-induced activation ofjun kinase (JNK) and AP-1 transactivation. To test the hypothesis that cytokine-induced protection was mediated through inhibition of JNK/c-jun, we also inhibited c-junfunction in 8226 cells via introduction of a mutant dominant negative c-jun construct. Mutant c-jun–containing MM cells were also resistant to anti–fas-induced apoptosis but were significantly more sensitive to dexamethasone-induced apoptosis. These results support the notion that IL-6 protects MM cells against anti-fas through its inhibitory effects on JNK/c-junbut indicate protection against dexamethasone occurs through separate, yet unknown pathways.

Incidence of apoptosis and cell proliferation in multiple myeloma. Correlation with bcl-2 protein expression and serum levels of interleukin-6 (IL-6) and soluble IL-6 receptor

2002 ◽  
Vol 69 (2) ◽  
pp. 90-94 ◽  
Author(s):  
Aristeidis I. Chaidos ◽  
Maria C. Bai ◽  
Sevasti A. Kamina ◽  
Panayiotis E. Kanavaros ◽  
Niki J. Agnantis ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Proliferation ◽  
Protein Expression ◽  
Interleukin 6 ◽  
Serum Levels

Improved superoxide-generating ability by interferon γ due to splicing pattern change of transcripts in neutrophils from patients with a splice site mutation inCYBB gene

Blood ◽  
2001 ◽  
Vol 98 (2) ◽  
pp. 436-441 ◽  
Author(s):  
Fuminari Ishibashi ◽  
Tomoyuki Mizukami ◽  
Shiro Kanegasaki ◽  
Lena Motoda ◽  
Ryota Kakinuma ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Present Report ◽  
Interferon Γ ◽  
Silent Mutation ◽  
Site Mutation ◽  
Splicing Pattern ◽  
Cybb Gene ◽  
Gene Transcripts ◽  
Ifn Γ ◽  
Neutrophil Superoxide

Chronic granulomatous disease (CGD) is an inherited disorder of host defense against microbial infections caused by defective activity of the phagocyte NADPH oxidase. Based on an increase of neutrophil superoxide-generating ability in response to interferon γ (IFN-γ) in a single patient with CGD, multicentered group studies demonstrated a beneficial effect of prophylactic IFN-γ. However, no apparent increase of the phagocyte superoxide generation was found in patients enrolled in these studies. The present report offers an additional kindred in whom an IFN-γ–dependent increase in neutrophil superoxide production was observed in 3 affected patients. The defect in the CYBB gene for gp91-phox was identified as an otherwise silent mutation adjacent to the third intron of theCYBB gene that alters messenger RNA splicing. By molecular analysis, significant differences were found in the splicing pattern ofCYBB gene transcripts in patient neutrophils between 1 and 25 days after administration of IFN-γ. Furthermore, a complete transcript containing the missing exons could be detected in all specimens after the treatment. The changes in the splicing pattern of the transcripts and the prolonged effect on superoxide-generating ability of patient neutrophils indicate that IFN-γ induced a partial correction of the abnormal splicing of CYBB gene transcripts in myeloid progenitor cells.

Fas/APO-1 (CD95)–Mediated Apoptosis Is Activated by Interferon-γ and Interferon- in Interleukin-6 (IL-6)–Dependent and IL-6–Independent Multiple Myeloma Cell Lines

Blood ◽  
1998 ◽  
Vol 92 (8) ◽  
pp. 2914-2923 ◽  
Author(s):  
Helena Spets ◽  
Patrik Georgii-Hemming ◽  
Jan Siljason ◽  
Kenneth Nilsson ◽  
Helena Jernberg-Wiklund
Keyword(s):  
Multiple Myeloma ◽  
Cell Lines ◽  
Poor Response ◽  
Antigen Expression ◽  
Myeloma Cell ◽  
Interferon Γ ◽  
Dependent Manner ◽  
Multiple Myeloma Cell ◽  
Ifn Γ ◽  
Induced Apoptosis

Abstract A poor response to Fas-induced apoptosis is evident in some multiple myeloma (MM) cell lines and primary cells. In this study, we have examined the possibility to increase the sensitivity to Fas-induced apoptosis by pretreatment of MM cells with interferon-γ (IFN-γ) or interferon- (IFN-). Both IFN-γ and IFN- markedly increased the Fas-induced apoptosis in all cell lines tested (U-266-1970, U-266-1984, and U-1958). In the U-266-1970 and U-1958 cell lines, pretreatment with either IFN-γ or IFN- also inhibited proliferation in a dose-dependent manner. In contrast, IFN-γ activation of the Fas death pathway in the U-266-1984 cells was not accompanied by growth inhibition. Incubation with the IFNs increased the Fas antigen expression in one of three cell lines but did not alter the expression of Bcl-2 or Bax. The IFNs are important regulators of growth and survival in MM cells. Our results suggest that activation of Fas-mediated apoptosis is a novel mechanism by which the IFNs exert inhibitory effects on MM cells. © 1998 by The American Society of Hematology.

scholarly journals Interleukin-6 promotes multiple myeloma cell growth via phosphorylation of retinoblastoma protein

Blood ◽  
1996 ◽  
Vol 88 (6) ◽  
pp. 2219-2227 ◽  
Author(s):  
M Urashima ◽  
A Ogata ◽  
D Chauhan ◽  
MB Vidriales ◽  
G Teoh ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
B Cells ◽  
Cell Growth ◽  
Tumor Cell ◽  
Cell Lines ◽  
Interleukin 6 ◽  
Growth Arrest ◽  
Retinoblastoma Protein ◽  
Myeloma Cell ◽  
Phosphorylated Form

Interleukin-6 (IL-6) mediates autocrine and paracrine growth of multiple myeloma (MM) cells and inhibits tumor cell apoptosis. Abnormalities of retinoblastoma protein (pRB) and mutations of RB gene have been reported in up to 70% of MM patients and 80% of MM-derived cell lines. Because dephosphorylated (activated) pRB blocks transition from G1 to S phase of the cell cycle whereas phosphorylated (inactivated) pRB releases this growth arrest, we characterized the role of pRB in IL-6-mediated MM cell growth. Both phosphorylated and dephosphorylated pRB were expressed in all serum-starved MM patient cells and MM-derived cell lines, but pRB was predominantly in its phosphorylated form. In MM cells that proliferated in response to IL-6, exogenous IL-6 downregulated dephosphorylated pRB and decreased dephosphorylated pRB-E2F complexes. Importantly, culture of MM cells with RB antisense, but not RB sense, oligonucleotide (ODN) triggered IL- 6 secretion and proliferation in MM cells; however, proliferation was only partially inhibited by neutralizing anti-IL-6 monoclonal antibody (MoAb). In contrast to MM cells, normal splenic B cells express dephosphorylated pRB. Although CD40 ligand (CD40L) triggers a shift from dephosphorylated to phosphorylated pRB and proliferation of B cells, the addition of exogenous IL-6 to CD40L-treated B cells does not alter either pRB or proliferation, as observed in MM cells. These results suggest that phosphorylated pRB is constitutively expressed in MM cells and that IL-6 further shifts pRB from its dephosphorylated to its phosphorylated form, thereby promoting MM cell growth via two mechanisms; by decreasing the amount of E2F bound by dephosphorylated pRB due to reduced dephosphorylated pRB, thereby releasing growth arrest; and by upregulating IL-6 secretion by MM cells and related IL-6- mediated autocrine tumor cell growth.

Effect of the specific P53 stabilizer CBS9106 on multiple myeloma (MM)

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. 8601-8601
Author(s):  
H. Ikeda ◽  
T. Hideshima ◽  
G. Perrone ◽  
Y. Okawa ◽  
N. Raje ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Protein Expression ◽  
Tumor Cells ◽  
Cell Lines ◽  
Primary Tumor ◽  
P53 Protein ◽  
Wild Type ◽  
Cycle Arrest ◽  
P53 Protein Expression

8601 Background: The mutations of P53 tumor suppressor protein are associated with progressive in Multiple Myeloma (MM), conversely, stabilization of P53 leads to cell cycle arrest and apoptosis. In this study, we examined p53 protein expression and demonstrated the effect of P53 stabilization using a novel specific P53 stabilizer CBS9106 in MM. Method: We examined P53 protein expression using Immunoblot analysis, as well as the growth inhibitory effect of CBS9106 in MM cell lines and primary tumor cells from MM patients. We also defined whether CBS9106 can overcome the growth promoting effect of exogenous cytokines and bone marrow stroma cells (BMSCs) using [3H]-thymidine uptake assay. Results: Expression of P53 protein was observed in 3/3 primary tumor cells from MM patients and 6/6 MM cell lines. CBS9106 at low nM levels triggered cytotoxicity against p53 wild type MM cell lines and primary tumor cells from MM patients, associated with phosphorylation of P53 (serine15 and 20). In contrast, CBS9106 did not affect the survival of normal peripheral blood mononuclear cells from healthy volunteers at concentrations as high as 10 μM. This agent also induced G1 cell cycle arrest, followed by apoptosis associated with cleavage of caspase-3, -8, -9 and PARP. Neither growth stimulating cytokines (IL-6 and IGF-1) nor BMSCs protected against apoptotic effect of CBS9106. Moreover, we demonstrate that combination of CBS9106 with MDM2 inhibitor Nutrin3 or proteasome inhibitor bortezomib induces synergistic anti-MM activity in both P53 wild type MM cell lines and primary tumor cells from MM patients. Conclusions: Stabilizing P53 by CBS9106 represents a novel promising p53-based therapy in MM. These results provide the preclinical framework supporting evaluation of CBS9106 in clinical trials to improve patient outcome in MM. No significant financial relationships to disclose.

Systemic Sclerosis Fibroblasts Show Specific Alterations of Interferon-γ and Tumor Necrosis Factor-α-induced Modulation of Interleukin 6 and Chemokine Ligand 2

2012 ◽  
Vol 39 (5) ◽  
pp. 979-985 ◽  
Author(s):  
ALESSANDRO ANTONELLI ◽  
POUPAK FALLAHI ◽  
SILVIA MARTINA FERRARI ◽  
DILIA GIUGGIOLI ◽  
MICHELE COLACI ◽  
...  
Keyword(s):  
Systemic Sclerosis ◽  
Tumor Necrosis Factor ◽  
Interleukin 6 ◽  
Tumor Necrosis ◽  
Tumor Necrosis Factor Α ◽  
Interferon Γ ◽  
Tnf Α ◽  
Ifn Γ ◽  
Factor Α ◽  
Necrosis Factor

Objective.We evaluated the effect of interferon-γ (IFN-γ) and/or tumor necrosis factor-α (TNF-α) on the secretion of prototype proinflammatory cytokine interleukin 6 (IL-6), compared to T-helper 1 [Th1; chemokine (C-X-C motif) ligand 10 (CXCL10)] or Th2 [chemokine (C-C motif) ligand 2 (CCL2)] chemokines, in primary cultured fibroblasts from patients with systemic sclerosis (SSc) at an early stage of the disease.Methods.Fibroblast cultures from 5 SSc patients (disease duration < 2 yrs) and 5 healthy controls were evaluated for the production of IL-6, CXCL10, and CCL2 at the basal level and after stimulation with IFN-γ and/or TNF-α.Results.SSc fibroblasts basally produced higher levels of IL-6 than controls, while no difference was observed about CCL2 and CXCL10. TNF-α was able to dose-dependently induce IL-6 and CCL2 secretion in SSc, but not in control fibroblasts. By stimulation with increasing doses of IFN-γ, SSc fibroblasts were induced to secrete CCL2 and CXCL10, while no effect was observed on IL-6. The combination of IFN-γ and TNF-α induced a strong secretion of IL-6 and CCL2 in SSc fibroblasts but not in controls. In contrast, the synergistic effect of IFN-γ and TNF-α on CXCL10 secretion was similar in SSc fibroblasts and in controls.Conclusion.SSc fibroblasts participate in the self-perpetuation of inflammation by releasing IL-6, CXCL10, and CCL2 under the influence of IFN-γ and/or TNF-α. SSc fibroblasts are more active than controls in the secretion of IL-6 at baseline, and in the production of IL-6 and CCL2 under the combined IFN-γ/TNF-α stimulation.

scholarly journals Silica Nanoparticles Sensitize Human Multiple Myeloma Cells to Snake (Walterinnesia aegyptia) Venom-Induced Apoptosis and Growth Arrest

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Douaa Sayed ◽  
Mohamed K. Al-Sadoon ◽  
Gamal Badr
Keyword(s):  
Cell Cycle ◽  
Multiple Myeloma ◽  
Silica Nanoparticles ◽  
Biological Effects ◽  
Growth Arrest ◽  
Hematopoietic Stem ◽  
Human Multiple Myeloma ◽  
Induced Apoptosis ◽  
The Impact ◽  
Effective Treatments

Background. Multiple myeloma (MM), an almost incurable disease, is the second most common blood cancer. Initial chemotherapeutic treatment could be successful; however, resistance development urges the use of higher toxic doses accompanied by hematopoietic stem cell transplantation. The establishment of more effective treatments that can overcome or circumvent chemoresistance has become a priority. We recently demonstrated that venom extracted fromWalterinnesia aegyptia(WEV) either alone or in combination with silica nanoparticles (WEV+NPs) mediated the growth arrest and apoptosis of prostate cancer cells. In the present study, we evaluated the impact of WEV alone and WEV+NP on proliferation and apoptosis of MM cells.Methods. The impacts of WEV alone and WEV+NP were monitored in MM cells from 70 diagnosed patients. The influences of WEV and WEV+NP were assessed with flow cytometry analysis.Results. WEV alone and WEV+NP decreased the viability of MM cells. Using a CFSE proliferation assay, we found that WEV+NP strongly inhibited MM cell proliferation. Furthermore, analysis of the cell cycle using the propidium iodide (PI) staining method indicated that WEV+NP strongly altered the cell cycle of MM cells and enhanced the induction of apoptosis.Conclusions. Our data reveal the biological effects of WEV and WEV+NP on MM cells that enable these compounds to function as effective treatments for MM.

scholarly journals AMPK inhibits myoblast differentiation through a PGC-1α-dependent mechanism

2009 ◽  
Vol 297 (2) ◽  
pp. E304-E314 ◽  
Author(s):  
David L. Williamson ◽  
David C. Butler ◽  
Stephen E. Alway
Keyword(s):  
Cell Cycle ◽  
Skeletal Muscle ◽  
Protein Expression ◽  
Muscle Growth ◽  
Muscle Cells ◽  
Myoblast Differentiation ◽  
P21 Protein ◽  
Compound C ◽  
Ampk Phosphorylation ◽  
Cell Cycle Transition

Elevated phosphorylation of AMP-activated protein kinase (AMPK) has been shown to inhibit skeletal muscle growth in both culture and animal models, but its role in differentiation of muscle cells is less clear. p21 is known to have an important role in differentiation, but AMPK's role regulating p21 in differentiation in muscle cultures is unknown. Therefore, the purpose of this study was to determine the role of p21 in differentiation of skeletal muscle cells under conditions of elevated AMPK phosphorylation. Treating C2C12 myoblast cultures with 1 mM 5-aminoimidazole-4-carboxamide 1-β-d-ribonucleoside (AICAR) for up to 24 h induced AMPK phosphorylation. Activation of AMPK reduced p21 protein and mRNA expression, which was associated with reduced G1/S cell cycle transition and p21 promoter activity. AICAR-treated myoblasts undergoing differentiation also had reduced p21 protein expression, reduced myotube formation, and myosin accumulation. When myotube cultures were treated with AICAR for 24 h, p21, myosin protein expression, and MyoD were significantly reduced. Myotube atrophy was also apparent compared with control conditions. Addition of compound C, an AMPK inhibitor, attenuated AICAR's negative effects on the myotube cultures. The nuclear expression of p21 protein appeared to be more affected by AICAR-treated myotubes than the cytosolic portion of p21 protein, which was attenuated with compound C treatment. Further analysis revealed that AICAR treatment increased PGC-1α and decreased FOXO3A protein expression, which was reversed with compound C cotreatment. Knockdown of PGC-1α with shRNA corroborated the compound C data, preserving nuclear FOXO3A and p21 protein expression. These data demonstrate that AICAR-induced AMPK phosphorylation inhibits cell cycle transition, reducing differentiation of myoblasts into myotubes, through PGC-1α-FOXO3A-p21.

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