1
|
Xu J, Ji Y, Shogren KL, Okuno SH, Yaszemski MJ, Maran A. RNA-dependent protein kinase is required for interferon-γ-induced autophagy in MG63 osteosarcoma cells. Gene 2021; 802:145865. [PMID: 34352301 DOI: 10.1016/j.gene.2021.145865] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/30/2021] [Indexed: 02/08/2023]
Abstract
Osteosarcoma is a bone tumor that mainly affects children and adolescents. Interferons (IFNs) have been shown to exert antitumor effects in osteosarcoma cells, although the molecular mechanisms have not been fully realized. We investigated IFN-γ actions on osteosarcoma cells. Our results show that IFN-γ induces the accumulation of autophagosomes in osteosarcoma cells. IFN-γ treatment leads to the conversion of autophagy marker light chain 3 (LC3)-I to LC3-II in osteosarcoma cells, and this conversion is accompanied by puncta formation. Also, IFN-γ-mediated induction of autophagosome formation and autophagic flux require RNA-dependent protein kinase (PKR) activity. In addition, our findings show that IFN-γ-mediated osteosarcoma cell death is not dependent on PKR. Our study suggests that IFN-γ has differential effects that lead to induction of cell death and autophagy in osteosarcoma cells. Further evaluation of the IFN-γ-mediated molecular mechanism could lead to improved understanding of and targeted treatment strategies for osteosarcoma.
Collapse
Affiliation(s)
- Jie Xu
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Musculoskeletal Center, Peking University People's Hospital, Beijing, China
| | - Yuqing Ji
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA; Department of Orthopedic Oncology, Qilu Hospital (Qingdao), Shandong University, Qingdao, China
| | | | - Scott H Okuno
- Department of Oncology, Mayo Clinic, Rochester, MN, USA
| | | | | |
Collapse
|
2
|
Zuo D, Shogren KL, Zang J, Jewison DE, Waletzki BE, Miller AL, Okuno SH, Cai Z, Yaszemski MJ, Maran A. Inhibition of STAT3 blocks protein synthesis and tumor metastasis in osteosarcoma cells. JOURNAL OF EXPERIMENTAL & CLINICAL CANCER RESEARCH : CR 2018; 37:244. [PMID: 30286779 PMCID: PMC6172747 DOI: 10.1186/s13046-018-0914-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Accepted: 09/20/2018] [Indexed: 02/07/2023]
Abstract
BACKGROUND Osteosarcoma is the most common bone cancer. Despite advances, molecular mechanisms associated with osteosarcoma have not been fully understood. Hence, an effective treatment for osteosarcoma has yet to be developed. Even though signal transducer and activator of transcription3 (STAT3) has been implicated, its role in pathogenesis of osteosarcoma is not fully determined. In this study, we investigated the antitumor effect of napabucasin (NP) (BBI608), an inhibitor of STAT3 on osteosarcoma in vitro and in vivo and studied the underlying molecular mechanism. METHODS Cell viability, colony formation, apoptosis, tumor growth and metastasis assays were performed to examine the effect of NP on osteosarcoma in vitro and in vivo. Real-time RT-PCR, western analysis, immunofluorescence and reporter assays were used to monitor the expression and activity of proteins and underlying molecular pathways. Protein synthesis, co-immunoprecipitation and CAP binding assays were carried out to understand NP-mediated mechanism of actions in osteosarcoma cells. RESULTS Our results show that NP treatment decreases cell viability and induces apoptosis in several osteosarcoma cell lines. NP treatment suppresses both expression and phosphorylation of STAT3 in addition to blocking STAT3-mediated transcription and downstream target proteins in osteosarcoma cells. Furthermore, NP inhibits protein synthesis through regulation of the eukaryotic initiation factor 4E (eIF4E) and eIF4E-binding protein 1 (4E-BP1). NP also inhibits the progression of osteosarcoma tumors and metastasis in vivo in an orthotopic tibial model of osteosarcoma. CONCLUSIONS Taken together, our investigation reveals that NP acts through a novel mechanism and inhibits osteosarcoma growth and metastasis, and could be investigated clinically for treating osteosarcoma patients alone or in combination with other drugs.
Collapse
Affiliation(s)
- Dongqing Zuo
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.,Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Kristen L Shogren
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Jie Zang
- Musculoskeletal Tumor Center, People's Hospital, Peking University, Beijing, 100044, China
| | - Donna E Jewison
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Brian E Waletzki
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | | | - Scott H Okuno
- Division of Medical Oncology, Mayo Clinic, Rochester, MN, USA
| | - Zhengdong Cai
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Michael J Yaszemski
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA
| | - Avudaiappan Maran
- Department of Orthopedic Surgery, 2-69 Medical Sciences, Mayo Clinic, 200 First St SW, Rochester, MN, 55905, USA.
| |
Collapse
|
3
|
Bravo D, Shogren KL, Zuo D, Wagner ER, Sarkar G, Yaszemski MJ, Maran A. 2-Methoxyestradiol-Mediated Induction of Frzb Contributes to Cell Death and Autophagy in MG63 Osteosarcoma Cells. J Cell Biochem 2017; 118:1497-1504. [PMID: 27883247 DOI: 10.1002/jcb.25809] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/22/2016] [Indexed: 12/31/2022]
Abstract
Osteosarcoma is a bone tumor that mainly affects children and adolescents. Although its pathogenesis is still not fully understood, activation of Wnt signaling has been implicated in the development and metastasis of osteosarcoma. In this report, we have investigated the effect of the anti-tumor compound, 2-methoxyestradiol (2-ME) on Wnt antagonist frizzled-related protein b (Frzb), also known as secreted frizzled-related protein (sFRP)3 in human osteosarcoma (MG63) cells. Our results show that 2-ME treatment induces Frzb gene promoter activity, and increases Frzb mRNA and protein levels in osteosarcoma cells. In addition, 2-ME treatment regulates downstream Wnt signaling, increasing the cytoplasmic levels of β-catenin, and blocking β-catenin-mediated Wnt activation in osteosarcoma cells. 2-ME-mediated induction of Frzb protein expression is specific to osteosarcoma cells, as it does not affect Frzb expression in normal primary human osteoblasts. Furthermore, 2-ME-induced apoptosis and autophagy are blocked in osteosarcoma cells transfected with Frzb siRNAs. Taken together, these studies demonstrate that Frzb protein plays an important role in 2-ME-mediated anti-tumor mechanisms in osteosarcoma cells. J. Cell. Biochem. 118: 1497-1504, 2017. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Dalibel Bravo
- Department of Orthopedic surgery, Mayo Clinic, Rochester, Minnesota
| | | | - Dongqing Zuo
- Department of Orthopedic surgery, Mayo Clinic, Rochester, Minnesota
| | - Eric R Wagner
- Department of Orthopedic surgery, Mayo Clinic, Rochester, Minnesota
| | - Gobinda Sarkar
- Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota
| | | | | |
Collapse
|
4
|
Roles of PKR in differentiation and apoptosis of bone-related cells. Anat Sci Int 2016; 92:313-319. [DOI: 10.1007/s12565-016-0385-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 11/25/2016] [Indexed: 12/13/2022]
|
5
|
Shinohara H, Teramachi J, Okamura H, Yang D, Nagata T, Haneji T. Double Stranded RNA-Dependent Protein Kinase is Necessary for TNF-α-Induced Osteoclast Formation In Vitro and In Vivo. J Cell Biochem 2016; 116:1957-67. [PMID: 25739386 DOI: 10.1002/jcb.25151] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Accepted: 02/27/2015] [Indexed: 12/12/2022]
Abstract
Double-stranded RNA-dependent protein kinase (PKR) is involved in cell cycle progression, cell proliferation, cell differentiation, tumorgenesis, and apoptosis. We previously reported that PKR is required for differentiation and calcification in osteoblasts. TNF-α plays a key role in osteoclast differentiation. However, it is unknown about the roles of PKR in the TNF-α-induced osteoclast differentiation. The expression of PKR in osteoclast precursor RAW264.7 cells increased during TNF-α-induced osteoclastogenesis. The TNF-α-induced osteoclast differentiation in bone marrow-derived macrophages and RAW264.7 cells was markedly suppressed by the pretreatment of PKR inhibitor, 2-aminopurine (2AP), as well as gene silencing of PKR. The expression of gene markers in the differentiated osteoclasts including TRAP, Calcitonin receptor, cathepsin K, and ATP6V0d2 was also suppressed by the 2AP treatment. Bone resorption activity of TNF-α-induced osteoclasts was also supressed by 2AP treatment. Inhibition of PKR supressed the TNF-α-induced activation of NF-κB and MAPK in RAW264.7 cells. 2AP inhibited both the nuclear translocation of NF-κB and its transcriptional activity in RAW264.7 cells. 2AP inhibited the TNF-α-induced expression of NFATc1 and c-fos, master transcription factors in osteoclastogenesis. TNF-α-induced nuclear translocation of NFATc1 in mature osteoclasts was clearly inhibited by the 2AP treatment. The PKR inhibitor C16 decreased the TNF-α-induced osteoclast formation and bone resorption in mouse calvaria. The present study indicates that PKR is necessary for the TNF-α-induced osteoclast differentiation in vitro and in vivo.
Collapse
Affiliation(s)
- Hiroki Shinohara
- Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.,Department of Periodontology and Endodontology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Jumpei Teramachi
- Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Hirohiko Okamura
- Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Di Yang
- Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Toshihiko Nagata
- Department of Periodontology and Endodontology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| | - Tatsuji Haneji
- Department of Histology and Oral Histology, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan
| |
Collapse
|
6
|
The estrogen metabolite 2-methoxyestradiol regulates eukaryotic initiation factor 4E (eIF4E) and inhibits protein synthesis in MG63 osteosarcoma cells. Genes Dis 2016; 3:153-158. [PMID: 30258883 PMCID: PMC6147162 DOI: 10.1016/j.gendis.2016.04.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/10/2016] [Indexed: 12/23/2022] Open
Abstract
Osteosarcoma is a primary bone tumor that affects children and young adults. The estrogen metabolite 2-methoxyestradiol (2-ME) induces cell death in osteosarcoma cells. To determine whether 2-ME actions involve the control of protein synthesis, we studied the effect of 2-ME on eukaryotic initiation factor 4E (eIF4E) and eIF4E-binding protein 1 (4E-BP1) in MG63 osteosarcoma cells. Our results show that 2-ME treatment increases the association of eIF4E with 4E-BP1 in osteosarcoma cells. Also, 2-ME decreases the binding of eIF4E protein to 7-methyl-guanosine cap structure, indicating that 2-ME treatment results in the inhibition of translational initiation. These findings are further supported by the inhibition of protein synthesis in 2-ME-treated osteosarcoma cells. Taken together, our studies show that 2-ME-mediated antitumor effects in osteosarcoma cells involve the regulation of protein synthesis, and translational machinery could serve as a target in the treatment of osteosarcoma.
Collapse
|
7
|
Reumann S, Shogren KL, Yaszemski MJ, Maran A. Inhibition of Autophagy Increases 2-Methoxyestradiol-Induced Cytotoxicity in SW1353 Chondrosarcoma Cells. J Cell Biochem 2015; 117:751-9. [DOI: 10.1002/jcb.25360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 09/01/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Stephan Reumann
- Department of Orthopedics; College of Medicine; Mayo Clinic Rochester, Minnesota 55905
- Paracelsus Medical University; Salzburg; Austria
| | - Kristen L. Shogren
- Department of Orthopedics; College of Medicine; Mayo Clinic Rochester, Minnesota 55905
| | - Michael J. Yaszemski
- Department of Orthopedics; College of Medicine; Mayo Clinic Rochester, Minnesota 55905
| | - Avudaiappan Maran
- Department of Orthopedics; College of Medicine; Mayo Clinic Rochester, Minnesota 55905
| |
Collapse
|
8
|
Maran A, Dadsetan M, Buenz CM, Shogren KL, Lu L, Yaszemski MJ. Hydrogel-PLGA delivery system prolongs 2-methoxyestradiol-mediated anti-tumor effects in osteosarcoma cells. J Biomed Mater Res A 2013; 101:2491-9. [DOI: 10.1002/jbm.a.34550] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 11/02/2012] [Accepted: 11/13/2012] [Indexed: 11/08/2022]
|
9
|
Yang C, Shogren KL, Goyal R, Bravo D, Yaszemski MJ, Maran A. RNA-dependent protein kinase is essential for 2-methoxyestradiol-induced autophagy in osteosarcoma cells. PLoS One 2013; 8:e59406. [PMID: 23527187 PMCID: PMC3602192 DOI: 10.1371/journal.pone.0059406] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 02/16/2013] [Indexed: 11/26/2022] Open
Abstract
Osteosarcoma is the most common primary malignant bone tumor in children and young adults. Surgical resection and adjunctive chemotherapy are the only widely available options of treatment for this disease. Anti-tumor compound 2-Methoxyestradiol (2-ME) triggers cell death through the induction of apoptosis in osteosarcoma cells, but not in normal osteoblasts. In this report, we have investigated whether autophagy plays a role in 2-ME actions on osteosarcoma cells. Transmission electron microscopy imaging shows that 2-ME treatment leads to the accumulation of autophagosomes in human osteosarcoma cells. 2-ME induces the conversion of the microtubule-associated protein LC3-I to LC3-II, a biochemical marker of autophagy that is correlated with the formation of autophagosomes. Conversion to LC3-II is accompanied by protein degradation in 2-ME-treated cells. 2-ME does not induce autophagosome formation in normal primary human osteoblasts. In addition, 2-ME-dependent autophagosome formation in osteosarcoma cells requires ATG7 expression. Furthermore, 2-ME does not induce accumulation of autophagosomes in osteosarcoma cells that express dominant negative mutant RNA-dependent protein kinase (PKR) and are resistant to anti-proliferative and anti-tumor effects of 2-ME. Taken together, our study shows that 2-ME treatment induces PKR-dependent autophagy in osteosarcoma cells, and that autophagy could play an important role in 2-ME-mediated anti-tumor actions and in the control of osteosarcoma.
Collapse
Affiliation(s)
- Caihong Yang
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
- Department of Orthopedic, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kristen L. Shogren
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Ribu Goyal
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Dalibel Bravo
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Michael J. Yaszemski
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Avudaiappan Maran
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota, United States of America
| |
Collapse
|
10
|
Wimbauer F, Yang C, Shogren KL, Zhang M, Goyal R, Riester SM, Yaszemski MJ, Maran A. Regulation of interferon pathway in 2-methoxyestradiol-treated osteosarcoma cells. BMC Cancer 2012; 12:93. [PMID: 22429849 PMCID: PMC3414746 DOI: 10.1186/1471-2407-12-93] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Accepted: 03/19/2012] [Indexed: 12/20/2022] Open
Abstract
Background Osteosarcoma is a bone tumor that often affects children and young adults. Although a combination of surgery and chemotherapy has improved the survival rate in the past decades, local recurrence and metastases still develop in 40% of patients. A definite therapy is yet to be determined for osteosarcoma. Anti- tumor compound and a metabolite of estrogen, 2-methoxyestradiol (2-ME) induces cell death in osteosarcoma cells. In this report, we have investigated whether interferon (IFN) pathway is involved in 2-ME-induced anti-tumor effects in osteosarcoma cells. Methods 2-ME effects on IFN mRNA levels were determined by Real time PCR analysis. Transient transfections followed by reporter assays were used for investigating 2-ME effects on IFN-pathway. Western blot analyses were used to measure protein and phosphorylation levels of IFN-regulated eukaryotic initiation factor-2 alpha (eIF-2α). Results 2-ME regulates IFN and IFN-mediated effects in osteosarcoma cells. 2 -ME induces IFN gene activity and expression in osteosarcoma cells. 2-ME treatment induced IFN-stimulated response element (ISRE) sequence-dependent transcription and gamma-activated sequence (GAS)-dependent transcription in several osteosarcoma cells. Whereas, 2-ME did not affect IFN gene and IFN pathways in normal primary human osteoblasts (HOB). 2-ME treatment increased the phosphorylation of eIF-2α in osteosarcoma cells. Furthermore, analysis of osteosarcoma tissues shows that the levels of phosphorylated form of eIF-2α are decreased in tumor compared to normal controls. Conclusions 2-ME treatment triggers the induction and activity of IFN and IFN pathway genes in 2-ME-sensitive osteosarcoma tumor cells but not in 2-ME-resistant normal osteoblasts. In addition, IFN-signaling is inhibited in osteosarcoma patients. Thus, IFN pathways play a role in osteosarcoma and in 2-ME-mediated anti-proliferative effects, and therefore targeted induction of IFN signaling could lead to effective treatment strategies in the control of osteosarcoma.
Collapse
Affiliation(s)
- Fritz Wimbauer
- Department of Orthopedics, College of Medicine, Mayo Clinic, Rochester, MN 55906, USA
| | | | | | | | | | | | | | | |
Collapse
|
11
|
Teramachi J, Morimoto H, Baba R, Doi Y, Hirashima K, Haneji T. Double stranded RNA-dependent protein kinase is involved in osteoclast differentiation of RAW264.7 cells in vitro. Exp Cell Res 2010; 316:3254-62. [DOI: 10.1016/j.yexcr.2010.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2010] [Revised: 07/29/2010] [Accepted: 08/16/2010] [Indexed: 11/16/2022]
|
12
|
Papadakis AI, Paraskeva E, Peidis P, Muaddi H, Li S, Raptis L, Pantopoulos K, Simos G, Koromilas AE. eIF2α Kinase PKR Modulates the Hypoxic Response by Stat3-Dependent Transcriptional Suppression of HIF-1α. Cancer Res 2010; 70:7820-9. [DOI: 10.1158/0008-5472.can-10-0215] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
13
|
Benedikt MB, Mahlum EW, Shogren KL, Subramaniam M, Spelsberg TC, Yaszemski MJ, Maran A. 2-methoxyestradiol-mediated anti-tumor effect increases osteoprotegerin expression in osteosarcoma cells. J Cell Biochem 2010; 109:950-6. [PMID: 20082321 DOI: 10.1002/jcb.22473] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Osteosarcoma is a bone tumor that frequently develops during adolescence. 2-Methoxyestradiol (2-ME), a naturally occurring metabolite of 17beta-estradiol, induces cell cycle arrest and cell death in human osteosarcoma cells. To investigate whether the osteoprotegrin (OPG) protein plays a role in 2-ME actions, we studied the effect of 2-ME treatment on OPG gene expression in human osteosarcoma cells. 2-ME treatment induced OPG gene promoter activity and mRNA levels. Also, Western blot analysis showed that 2-ME treatment increased OPG protein levels in MG63, KHOS, 143B and LM7 osteosarcoma cells by 3-, 1.9-, 2.8-, and 2.5-fold, respectively, but did not affect OPG expression in normal bone cells. In addition, increases in OPG protein levels were observed in osteosarcoma cell culture media after 3 days of 2-ME treatment. The effect of 2-ME on osteosarcoma cells was ligand-specific as parent estrogen, 17beta-estradiol and a tumorigenic estrogen metabolite, 16alpha-hydroxyestradiol, which do not affect osteosarcoma cell cycle and cell death, had no effect on OPG protein expression. Furthermore, co-treating osteosarcoma cells with OPG protein did not further enhance 2-ME-mediated anti-tumor effects. OPG-released in 2-ME-treated cultures led to an increase in osteoblastic activity and a decrease in osteoclast number, respectively. These findings suggest that OPG is not directly involved in 2-ME-mediated anti-proliferative effects in osteosarcoma cells, but rather participates in anti-resorptive functions of 2-ME in bone tumor environment.
Collapse
Affiliation(s)
- Michaela B Benedikt
- Department of Orthopedics, College of Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA
| | | | | | | | | | | | | |
Collapse
|
14
|
KHAN ALIYAA, SÁNDOR GEORGEK, DORE EDWARD, MORRISON ARCHIBALDD, ALSAHLI MAZEN, AMIN FAIZAN, PETERS EDMUND, HANLEY DAVIDA, CHAUDRY SULTANR, LENTLE BRIAN, DEMPSTER DAVIDW, GLORIEUX FRANCISH, NEVILLE ALANJ, TALWAR REENAM, CLOKIE CAMERONM, MARDINI MAJDAL, PAUL TERRI, KHOSLA SUNDEEP, JOSSE ROBERTG, SUTHERLAND SUSAN, LAM DAVIDK, CARMICHAEL ROBERTP, BLANAS NICK, KENDLER DAVID, PETAK STEVEN, STE-MARIE LOUISGEORGES, BROWN JACQUES, EVANS A, RIOS LORENA, COMPSTON JULIETE. Bisphosphonate Associated Osteonecrosis of the Jaw. J Rheumatol 2009; 36:478-90. [DOI: 10.3899/jrheum.080759] [Citation(s) in RCA: 132] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In 2003, the first reports describing osteonecrosis of the jaw (ONJ) in patients receiving bisphosphonates (BP) were published. These cases occurred in patients with cancer receiving high-dose intravenous BP; however, 5% of the cases were in patients with osteoporosis receiving low-dose bisphosphonate therapy. We present the results of a systematic review of the incidence, risk factors, diagnosis, prevention, and treatment of BP associated ONJ. We conducted a comprehensive literature search for relevant studies on BP associated ONJ in oncology and osteoporosis patients published before February 2008.All selected relevant articles were sorted by area of focus. Data for each area were abstracted by 2 independent reviewers. The results showed that the diagnosis is made clinically. Prospective data evaluating the incidence and etiologic factors are very limited. In oncology patients receiving high-dose intravenous BP, ONJ appears to be dependent on the dose and duration of therapy, with an estimated incidence of 1%–12% at 36 months of exposure. In osteoporosis patients, it is rare, with an estimated incidence < 1 case per 100,000 person-years of exposure. The incidence of ONJ in the general population is not known. Currently, there is insufficient evidence to confirm a causal link between low-dose BP use in the osteoporosis patient population and ONJ. We concluded BP associated ONJ is associated with high-dose BP therapy primarily in the oncology patient population. Prevention and treatment strategies are currently based on expert opinion and focus on maintaining good oral hygiene and conservative surgical intervention.
Collapse
|
15
|
Abstract
BACKGROUND Bisphosphonates decrease bone resorption and are commonly used to treat or prevent osteoporosis. However, the effect of bisphosphonates on their target cells remains enigmatic, since in patients benefiting from therapy, little change, if any, has been observed in the number of osteoclasts, which are the cells responsible for bone resorption. METHODS We examined 51 bone-biopsy specimens obtained after a 3-year, double-blind, randomized, placebo-controlled, dose-ranging trial of oral alendronate to prevent bone resorption among healthy postmenopausal women 40 through 59 years of age. The patients were assigned to one of five groups: those receiving placebo for 3 years; alendronate at a dose of 1, 5, or 10 mg per day for 3 years; or alendronate at a dose of 20 mg per day for 2 years, followed by placebo for 1 year. Formalin-fixed, undecalcified planar sections were assessed by bone histomorphometric methods. RESULTS The number of osteoclasts was increased by a factor of 2.6 in patients receiving 10 mg of alendronate per day for 3 years as compared with the placebo group (P<0.01). Moreover, the number of osteoclasts increased as the cumulative dose of the drug increased (r=0.50, P<0.001). Twenty-seven percent of these osteoclasts were giant cells with pyknotic nuclei that were adjacent to superficial resorption cavities. Furthermore, giant, hypernucleated, detached osteoclasts with 20 to 40 nuclei were found after alendronate treatment had been discontinued for 1 year. Of these large cells, 20 to 37% were apoptotic, according to both their morphologic features and positive findings from in situ end labeling. CONCLUSIONS Long-term alendronate treatment is associated with an increase in the number of osteoclasts, which include distinctive giant, hypernucleated, detached osteoclasts that are undergoing protracted apoptosis.
Collapse
Affiliation(s)
- Robert S Weinstein
- Division of Endocrinology and Metabolism, the Center for Osteoporosis and Metabolic Bone Diseases, and the Central Arkansas Veterans Healthcare System, University of Arkansas for Medical Sciences, Little Rock 72205-7199, USA.
| | | | | |
Collapse
|
16
|
Maran A, Shogren KL, Benedikt M, Sarkar G, Turner RT, Yaszemski MJ. 2-methoxyestradiol-induced cell death in osteosarcoma cells is preceded by cell cycle arrest. J Cell Biochem 2008; 104:1937-45. [PMID: 18384113 DOI: 10.1002/jcb.21758] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
2-Methoxyestradiol (2-ME), a naturally occurring mammalian metabolite of 17beta-Estradiol (E2), induces cell death in osteosarcoma cells. To further understand the molecular mechanisms of action, we have investigated cell cycle progression in 2-ME-treated human osteosarcoma (MG63, SaOS-2 and LM7 [corrected]) cells. At 5 microM, 2-ME induced growth arrest by inducing a block in cell cycle; 2-ME-treatment resulted in 2-fold increases in G1 phase cells and a decrease in S phase cells in MG63 and SaOS-2 osteosarcoma cell lines, compared to the appropriate vehicle controls. 2-ME-treatment induced a threefold increase in the G2 phase in LM7 [corrected] osteosarcoma cells. The results demonstrated steroid specificity, as the tumorigenic metabolite, 16alpha-hydroxyestradiol (16-OHE), did not have any effect on cell cycle progression in osteosarcoma cells. The cell cycle arrest coincided with an increase in expression of the cell cycle markers p21, p27 and p53 proteins in 2-ME-treated osteosarcoma cells. Also, MG63 cells, transiently transfected with cDNA for a 'loss of function mutant' RNA-dependent protein kinase (PKR) protein, were resistant to 2-ME-induced cell cycle arrest. These results suggest that 2-ME works in concert with factors regulating cell cycle progression, and cell cycle arrest precedes cell death in 2-ME-treated osteosarcoma cells.
Collapse
Affiliation(s)
- Avudaiappan Maran
- Department of Orthopedics, Mayo Clinic, Rochester, Minnesota 55905, USA.
| | | | | | | | | | | |
Collapse
|