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Zhang Y, Zhang D, Meng Q, Liu Z, Xie H, Liu L, Xu F, Chen X. Precision treatment exploration of breast cancer based on heterogeneity analysis of lncRNAs at the single-cell level. BMC Cancer 2021; 21:918. [PMID: 34388989 PMCID: PMC8361656 DOI: 10.1186/s12885-021-08617-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 07/15/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Breast cancer (BC) is a complex disease with high heterogeneity, which often leads to great differences in treatment results. Current common molecular typing method is PAM50, which shows positive results for precision medicine; however, room for improvement still remains because of the different prognoses of subtypes. Therefore, in this article, we used lncRNAs, which are more tissue-specific and developmental stage-specific than other RNAs, as typing markers and combined single-cell expression profiles to retype BC, to provide a new method for BC classification and explore new precise therapeutic strategies based on this method. METHODS Based on lncRNA expression profiles of 317 single cells from 11 BC patients, SC3 was used to retype BC, and differential expression analysis and enrichment analysis were performed to identify biological characteristics of new subtypes. The results were validated for survival analysis using data from TCGA. Then, the downstream regulatory genes of lncRNA markers of each subtype were searched by expression correlation analysis, and these genes were used as targets to screen therapeutic drugs, thus proposing new precision treatment strategies according to the different subtype compositions of patients. RESULTS Seven lncRNA subtypes and their specific biological characteristics are obtained. Then, 57 targets and 210 drugs of 7 subtypes were acquired. New precision medicine strategies were proposed according to the different compositions of patient subtypes. CONCLUSIONS For patients with different subtype compositions, we propose a strategy to select different drugs for different patients, which means using drugs targeting multi subtype or combinations of drugs targeting a single subtype to simultaneously kill different cancer cells by personalized treatment, thus reducing the possibility of drug resistance and even recurrence.
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Affiliation(s)
- Yan Zhang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Denan Zhang
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Qingkang Meng
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Ziqi Liu
- Department of Pharmacy, The First Affiliated Hospital, Harbin Medical University, Harbin, 150001, Heilongjiang Province, P. R. China
| | - Hongbo Xie
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Lei Liu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Fei Xu
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China
| | - Xiujie Chen
- College of Bioinformatics Science and Technology, Harbin Medical University, Harbin, 150081, Heilongjiang Province, P. R. China.
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Joshi S. Targeting the Tumor Microenvironment in Neuroblastoma: Recent Advances and Future Directions. Cancers (Basel) 2020; 12:E2057. [PMID: 32722460 PMCID: PMC7465822 DOI: 10.3390/cancers12082057] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 07/21/2020] [Accepted: 07/23/2020] [Indexed: 12/30/2022] Open
Abstract
Neuroblastoma (NB) is the most common pediatric tumor malignancy that originates from the neural crest and accounts for more than 15% of all the childhood deaths from cancer. The neuroblastoma cancer research has long been focused on the role of MYCN oncogene amplification and the contribution of other genetic alterations in the progression of this malignancy. However, it is now widely accepted that, not only tumor cells, but the components of tumor microenvironment (TME), including extracellular matrix, stromal cells and immune cells, also contribute to tumor progression in neuroblastoma. The complexity of different components of tumor stroma and their resemblance with surrounding normal tissues pose huge challenges for therapies targeting tumor microenvironment in NB. Hence, the detailed understanding of the composition of the TME of NB is crucial to improve existing and future potential immunotherapeutic approaches against this childhood cancer. In this review article, I will discuss different components of the TME of NB and the recent advances in the strategies, which are used to target the tumor microenvironment in neuroblastoma.
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Affiliation(s)
- Shweta Joshi
- Department of Pediatrics, Division of Pediatric Hematology-Oncology, Moores Cancer Center, University of California San Diego, La Jolla, CA 92093-0815, USA
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Miranda KJ, Loeser RF, Yammani RR. Sumoylation and nuclear translocation of S100A4 regulate IL-1beta-mediated production of matrix metalloproteinase-13. J Biol Chem 2010; 285:31517-24. [PMID: 20685652 DOI: 10.1074/jbc.m110.125898] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
S100A4, a member of the S100 family of proteins, plays an important role in matrix remodeling by up-regulating the expression of matrix metalloproteinases (MMPs). We have previously shown that S100A4 is overexpressed in diseased cartilage and that extracellular S100A4 stimulates MMP-13 production, a major type II collagen-degrading enzyme, via activation of receptor for advanced glycation end product signaling. In the present study, using human articular chondrocytes, we show that intracellular S100A4 translocated into the nucleus upon interleukin-1β (IL-1β) stimulation and translocation required post-translational modification of S100A4 by the sumo-1 protein. Two sumoylation sites were identified on the S100A4 molecule, Lys(22) and Lys(96). Mutation of these lysine residues abolished the ability of S100A4 to be sumoylated and to translocate into the nucleus. Blocking of sumoylation and nuclear transport of S100A4 inhibited the IL-1β-induced production of MMP-13. Nuclear S100A4 was bound to the promoter region of MMP-13 in IL-1β-treated cells. Thus, we demonstrate a novel mechanism for sumoylated S100A4 as a regulator of expression of the MMP-13 gene.
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Affiliation(s)
- Keally J Miranda
- Section of Molecular Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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Yammani RR, Carlson CS, Bresnick AR, Loeser RF. Increase in production of matrix metalloproteinase 13 by human articular chondrocytes due to stimulation with S100A4: Role of the receptor for advanced glycation end products. ACTA ACUST UNITED AC 2006; 54:2901-11. [PMID: 16948116 DOI: 10.1002/art.22042] [Citation(s) in RCA: 163] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE S100 proteins have been implicated in various inflammatory conditions, including arthritis. The aims of this study were to determine whether chondrocytes produce S100A4 and whether S100A4 can stimulate the production of matrix metalloproteinase 13 (MMP-13) by articular chondrocytes via receptor for advanced glycation end products (RAGE)-mediated signaling. METHODS The expression of chondrocyte S100A4 was analyzed by immunohistochemistry using normal and osteoarthritic (OA) cartilage and by immunoblotting of chondrocyte cell lysates. RAGE signaling was examined by stimulating chondrocytes with S100A4 and monitoring for the activation of MAP kinases and NF-kappaB. Production of MMP-13 was determined in the conditioned medium. A pulldown assay using biotin-labeled S100A4 was used to demonstrate binding to RAGE. RESULTS S100A4 expression was detected in human articular chondrocytes by immunoblotting and appeared to increase in the cell lysates from OA tissue. Marked positive immunostaining for S100A4 was also noted in sections of human cartilage with changes due to OA. Stimulation of chondrocytes with S100A4 increased the phosphorylation of Pyk-2, MAP kinases, and activated NF-kappaB, followed by increased production of MMP-13 in the conditioned medium. This signaling was inhibited in cells pretreated with soluble RAGE, advanced glycation end product-bovine serum albumin, or the antioxidant Mn(III)tetrakis (4-benzoic acid) porphyrin, or by overexpression of a dominant-negative RAGE construct. A pulldown assay showed that S100A4 binds to RAGE in chondrocytes. CONCLUSION This is the first study to demonstrate that S100A4 binds to RAGE and stimulates a RAGE-mediated signaling cascade, leading to increased production of MMP-13. Since both S100A4 and RAGE are up-regulated in OA cartilage, this signaling pathway could contribute to cartilage degradation in OA.
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Affiliation(s)
- Raghunatha R Yammani
- Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA
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Saleem M, Kweon MH, Johnson JJ, Adhami VM, Elcheva I, Khan N, Bin Hafeez B, Bhat KMR, Sarfaraz S, Reagan-Shaw S, Spiegelman VS, Setaluri V, Mukhtar H. S100A4 accelerates tumorigenesis and invasion of human prostate cancer through the transcriptional regulation of matrix metalloproteinase 9. Proc Natl Acad Sci U S A 2006; 103:14825-30. [PMID: 16990429 PMCID: PMC1595436 DOI: 10.1073/pnas.0606747103] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
We previously showed that the calcium-binding protein S100A4 is overexpressed during the progression of prostate cancer (CaP) in humans and in the TRAMP (transgenic adenocarcinoma of the mouse prostate) mouse model. We tested a hypothesis that the S100A4 gene plays a role in the invasiveness of human CaP and may be associated with its metastatic spread. We observed that siRNA-mediated suppression of the S100A4 gene significantly reduced the proliferative and invasive capability of the highly invasive CaP cells PC-3. We evaluated the mechanism through which the S100A4 gene controls invasiveness of cells by using a macroarray containing 96 well characterized metastatic genes. We found that matrix metalloproteinase 9 (MMP-9) and its tissue inhibitor (TIMP-1) were highly responsive to S100A4 gene suppression. Furthermore, S100A4 suppression significantly reduced the expression and proteolytic activity of MMP-9. By employing an MMP-9-promoter reporter, we observed a significant reduction in the transcriptional activation of the MMP-9 gene in S100A4-siRNA-transfected cells. Cells overexpressing the S100A4 gene (when transfected with pcDNA3.1-S100A4 plasmid) also significantly expressed MMP-9 and TIMP-1 genes with increased proteolytic activity of MMP-9 concomitant to increased transcriptional activation of the MMP-9 gene. S100A4-siRNA-transfected cells exhibited a reduced rate of tumor growth under in vivo conditions. Our data demonstrate that the S100A4 gene controls the invasive potential of human CaP cells through regulation of MMP-9 and that this association may contribute to metastasis of CaP cells. We suggest that S100A4 could be used as a biomarker for CaP progression and a novel therapeutic or chemopreventive target for human CaP treatment.
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Affiliation(s)
- Mohammad Saleem
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | - Mee-Hyang Kweon
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | | | | | - Irina Elcheva
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | - Naghma Khan
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | - Bilal Bin Hafeez
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | - Kumar M. R. Bhat
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | - Sami Sarfaraz
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
| | | | | | | | - Hasan Mukhtar
- Department of Dermatology, University of Wisconsin, Madison, WI 53706
- *To whom correspondence should be addressed. E-mail:
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Gao XN, Tang SQ, Zhang XF. S100A4 antisense oligodeoxynucleotide suppresses invasive potential of neuroblastoma cells. J Pediatr Surg 2005; 40:648-52. [PMID: 15852272 DOI: 10.1016/j.jpedsurg.2005.01.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
BACKGROUND S100A4 gene product has been implicated in tumor invasion and metastasis. The overall survival rate of children with neuroblastoma remains poor because of disease dissemination at the time of diagnosis. The purpose of this study was to investigate the effect and mechanism of S100A4 on invasion and metastasis of neuroblastoma. METHODS A 20-mer phosphorothioate antisense oligodeoxynucleotide (asODN) targeted against the S100A4 mRNA was transfected into the human neuroblastoma cell line LA-N-6 by Lipofectamine 2000. The expressions of S100A4 and MMP-2 mRNAs were quantified by the reverse transcription polymerase chain reaction. The capability of migration and invasion of LA-N-6 cells were evaluated by the transwell chamber assay. RESULTS The S100A4 mRNA and the MMP-2 mRNA levels in asODN-treated cells were decreased by 35.6% and 25.5%, respectively, compared with those in nontreated cells. The numbers of migrating and invading LA-N-6 cells were both significantly lower in the asODN-treated groups than those in the nontreated groups ( 9.33 +/- 4.73 vs 20.67 +/- 2.89 and 2.33 +/- 1.15 vs 9.00 +/- 2.65, respectively; both P = .03 ). CONCLUSIONS The S100A4 asODN significantly reduced the S100A4 mRNA levels and the motility and invasive ability of neuroblastoma cells, with concomitant decrease of the MMP-2 mRNA levels. Thus, S100A4 may exert its effect on invasion and metastasis of neuroblastoma cells by stimulating the motility of tumor cells as well as influencing the expression of MMP-2.
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Affiliation(s)
- Xiao-ning Gao
- Department of Pediatrics, General Hospital of PLA, Beijing, PR China
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Semov A, Moreno MJ, Onichtchenko A, Abulrob A, Ball M, Ekiel I, Pietrzynski G, Stanimirovic D, Alakhov V. Metastasis-associated protein S100A4 induces angiogenesis through interaction with Annexin II and accelerated plasmin formation. J Biol Chem 2005; 280:20833-41. [PMID: 15788416 DOI: 10.1074/jbc.m412653200] [Citation(s) in RCA: 186] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Many advanced tumors overexpress and secrete the S100A4 protein that is known to promote angiogenesis and metastasis development. The mechanisms of this effect and the endothelial receptor for S100A4 are both still unknown. Here we report that extracellular S100A4 interacts with annexin II, an endothelial plasminogen co-receptor. Co-localization and direct binding of S100A4 and annexin II were demonstrated, and the binding site was identified in the N-terminal region of annexin II. S100A4 alone or in a complex with annexin II accelerated tissue plasminogen activator-mediated plasminogen activation in solution and on the endothelial cell surface through interaction of the S100A4 C-terminal lysines with the lysine-binding domains of plasminogen. A synthetic peptide corresponding to the N terminus of annexin II prevented S100A4-induced plasmin formation in the endothelial cell culture. Local plasmin formation induced by circulating S100A4 could contribute to tumor-induced angiogenesis and metastasis formation that makes this protein an attractive target for new anti-cancer and anti-angiogenic therapies.
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Harpio R, Einarsson R. S100 proteins as cancer biomarkers with focus on S100B in malignant melanoma. Clin Biochem 2005; 37:512-8. [PMID: 15234232 DOI: 10.1016/j.clinbiochem.2004.05.012] [Citation(s) in RCA: 144] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/04/2004] [Indexed: 12/22/2022]
Abstract
Although histochemical staining of the S100 protein family has been used for many years in the diagnosis of malignant melanoma, recent studies suggest one of the proteins comprising the S100 family, S100B, has particular utility in many aspects of the clinical management of malignant melanoma. This protein has been shown to be of use in staging malignant melanoma, in establishing prognosis, in evaluating treatment success and in predicting relapse. S100B is an independent prognostic factor and pretreatment circulating S100B concentrations predict duration of survival in melanoma patients. Survival is significantly longer in melanoma patients with normal S100B levels compared to those with elevated levels. Circulating S100B levels very sensitively detect metastatic growth of malignant melanoma, particularly in stage IV disease where S100B is certainly superior to other laboratory parameters. S100B concentrations reflect tumor mass. Serum S100B levels predict efficacy of treatment. Decreasing S100B concentrations reflect response to therapy while increasing S100B concentrations indicate tumor progression. Circulating S100B has a role to play in the decision to switch treatment regimens.
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Diomedi-Camassei F, Boldrini R, Ravà L, Donfrancesco A, Boglino C, Messina E, Dominici C, Callea F. Different pattern of matrix metalloproteinases expression in alveolar versus embryonal rhabdomyosarcoma. J Pediatr Surg 2004; 39:1673-9. [PMID: 15547833 DOI: 10.1016/j.jpedsurg.2004.07.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND/PURPOSE The matrix metalloproteinases (MMPs), a family of enzymes that degrade the extracellular matrix (ECM), are important in neoplastic cell invasion and metastasis. Data for rhabdomyosarcoma (RMS), the most frequent soft tissue sarcoma of childhood, are lacking. The aim of this study was to assess their expression in this tumor and to evaluate the correlation with clinicopathologic parameters. METHODS Immunohistochemical expression of MMP-1, MMP-2, MMP-3, MMP-7, MMP-9, TIMP-1, and TIMP-2 was investigated in 33 human RMSs, 12 alveolar, and 21 embryonal histologic subtypes (12 high risk and 9 low/standard risk). Evaluation of the results was based on the percent of positive neoplastic cells and on staining intensity (negative, moderate, and strong). In situ zymography was carried out on 4 frozen RMS samples (2 alveolar and 2 high-risk embryonal). RESULTS Alveolar type showed a stronger MMP-1, -2 and -9 expression in comparison with embryonal (P = .006, P <.001, and P <.001, respectively). Intratumoral vessels and perivascular ECM were positive for MMP-9 in the majority of RMSs. Both TIMPs had negative results. CONCLUSIONS Gelatinases MMP-2 and MMP-9 and collagenase MMP-1 overexpression seem to contribute to the more aggressive phenotype of alveolar rhabdomyoblastic cells. Further characterization of the expression of MMPs and consequent utilization of their inhibitors in aggressive alveolar RMSs might lead to the development of novel anticancer therapies.
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Schmidt-Hansen B, Ornås D, Grigorian M, Klingelhöfer J, Tulchinsky E, Lukanidin E, Ambartsumian N. Extracellular S100A4(mts1) stimulates invasive growth of mouse endothelial cells and modulates MMP-13 matrix metalloproteinase activity. Oncogene 2004; 23:5487-95. [PMID: 15122322 DOI: 10.1038/sj.onc.1207720] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
S100A4(mts1) protein expression has been strongly associated with metastatic tumor progression. It has been suggested as a prognostic marker for a number of human cancers. It is proposed that extracellular S100A4 accelerates cancer progression by stimulating the motility of endothelial cells, thereby promoting angiogenesis. Here we show that in 3D culture mouse endothelial cells (SVEC 4-10) respond to recombinant S100A4 by stimulating invasive growth of capillary-like structures. The outgrowth is not dependent on the stimulation of cell proliferation, but rather correlates with the transcriptional modulation of genes involved in the proteolytic degradation of extracellular matrix (ECM). Treatment of SVEC 4-10 with the S100A4 protein leads to the transcriptional activation of collagenase 3 (MMP-13) mRNA followed by subsequent release of the protein from the cells. Beta-casein zymography demonstrates enhancement of proteolytic activity associated with MMP-13. This observation indicates that extracellular S100A4 stimulates the production of ECM degrading enzymes from endothelial cells, thereby stimulating the remodeling of ECM. This could explain the angiogenic and metastasis-stimulating activity of S100A4(mts1).
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Affiliation(s)
- Birgitte Schmidt-Hansen
- Department of Molecular Cancer Biology, Institute for Cancer Biology, Danish Cancer Society, Strandboulevarden 49, DK-2100 Copenhagen, Denmark
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Underwood CK, Min D, Lyons JG, Hambley TW. The interaction of metal ions and Marimastat with matrix metalloproteinase 9. J Inorg Biochem 2003; 95:165-70. [PMID: 12763661 DOI: 10.1016/s0162-0134(03)00100-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effect of a range of metal ions on the ability of Marimastat to inhibit matrix metalloproteinase 9 (MMP-9) was examined in a fluorescence based proteolytic assay. Whilst none of the metals examined significantly affected the inhibitory ability of Marimastat, several metal ions did have a significant effect on MMP-9 activity itself. In the absence of Marimastat, Zn(II) and Fe(II) significantly inhibited MMP-9 activity at metal ion concentrations of 10 and 100 microM, respectively. In both the absence and presence of Marimastat, Cd(II) significantly inhibited MMP-9 at 100 microM. In contrast, 1 mM Co(II) significantly upregulated MMP-9 proteolytic activity.
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Affiliation(s)
- C K Underwood
- Centre for Heavy Metals Research, School of Chemistry, University of Sydney NSW, 2006 Australia
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Noujaim D, van Golen CM, van Golen KL, Grauman A, Feldman EL. N-Myc and Bcl-2 coexpression induces MMP-2 secretion and activation in human neuroblastoma cells. Oncogene 2002; 21:4549-57. [PMID: 12085233 DOI: 10.1038/sj.onc.1205552] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2001] [Revised: 03/20/2002] [Accepted: 03/27/2002] [Indexed: 02/07/2023]
Abstract
Neuroblastoma is a peripheral nervous system tumor that accounts for 8-10% of all solid childhood tumors. N-Myc is the most reliable prognostic indicator for neuroblastoma. Bcl-2 is detected in 40-60% of primary neuroblastoma tumors and demonstrates anti-apoptotic action by conferring resistance to chemotherapy and radiation treatment. In neuroblastoma cell lines, the coexpression of N-Myc and Bcl-2 leads to increased tumorigenic properties. Matrix metalloproteinases (MMPs) are endopeptidases that degrade a wide range of basement membrane components, a process important for tumor invasion. This study investigates the effect of N-Myc and Bcl-2 on MMP expression and activation. MMP-2 expression and secretion are increased in SHEP neuroblastoma cells expressing Bcl-2 alone (SHEP/Bcl-2 cells) or both N-Myc and Bcl-2 (SHEP/N-Myc/Bcl-2 cells). MMP-2 activity is increased in the SHEP/N-Myc/Bcl-2 cells yet remains unchanged in SHEP/Bcl-2 cells. TIMP-2 expression is high in SHEP/Bcl-2 cells, which likely inhibits MMP-2 activity, and absent in SHEP/N-Myc/Bcl-2 cells, allowing MMP-2 activity. Invasion is increased in SHEP/N-Myc/Bcl-2 cells and prevented by the use of a pharmacologic MMP-2 inhibitor. These data imply that N-Myc and Bcl-2 cooperate to increase the expression, secretion, and activation of MMP-2, which likely leads to a more tumorigenic phenotype due to increased MMP-2 mediated invasion.
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Affiliation(s)
- Daniel Noujaim
- Department of Neurology, University of Michigan, Ann Arbor 48109, USA
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