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Wang W, Li Y, Zhu JY, Fang D, Ding HF, Dong Z, Jing Q, Su SB, Huang S. Triple negative breast cancer development can be selectively suppressed by sustaining an elevated level of cellular cyclic AMP through simultaneously blocking its efflux and decomposition. Oncotarget 2016; 7:87232-87245. [PMID: 27901486 PMCID: PMC5349984 DOI: 10.18632/oncotarget.13601] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/07/2016] [Indexed: 01/13/2023] Open
Abstract
Triple negative breast cancer (TNBC) has the highest mortality among all breast cancer types and lack of targeted therapy is a key factor contributing to its high mortality rate. In this study, we show that 8-bromo-cAMP, a cyclic adenosine monophosphate (cAMP) analog at high concentration (> 1 mM) selectively suppresses TNBC cell growth. However, commonly-used cAMP-elevating agents such as adenylyl cyclase activator forskolin and pan phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (IBMX) are ineffective. Inability of cAMP elevating agents to inhibit TNBC cell growth is due to rapid diminution of cellular cAMP through efflux and decomposition. By performing bioinformatics analyses with publically available gene expression datasets from breast cancer patients/established breast cancer cell lines and further validating using specific inhibitors/siRNAs, we reveal that multidrug resistance-associated protein 1/4 (MRP1/4) mediate rapid cAMP efflux while members PDE4 subfamily facilitate cAMP decomposition. When cAMP clearance is prevented by specific inhibitors, forskolin blocks TNBC's in vitro cell growth by arresting cell cycle at G1/S phase. Importantly, cocktail of forskolin, MRP inhibitor probenecid and PDE4 inhibitor rolipram suppresses TNBC in vivo tumor development. This study suggests that a TNBC-targeted therapeutic strategy can be developed by sustaining an elevated level of cAMP through simultaneously blocking its efflux and decomposition.
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Affiliation(s)
- Wei Wang
- 1 Research Center for Traditional Chinese Medicine Complexity System, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Yue Li
- 2 Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Jessica Y. Zhu
- 2 Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL, USA
| | - Dongdong Fang
- 1 Research Center for Traditional Chinese Medicine Complexity System, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Han-Fei Ding
- 3 Georgia Cancer Center, Augusta University, Augusta, GA, USA
| | - Zheng Dong
- 4 Department of Anatomy and Cell Biology, Medical College of Georgia, Augusta University, Augusta, GA, USA
| | - Qing Jing
- 5 Changhai Hospital, Shanghai, China
| | - Shi-Bing Su
- 1 Research Center for Traditional Chinese Medicine Complexity System, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- 6 E-institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Shuang Huang
- 1 Research Center for Traditional Chinese Medicine Complexity System, Shanghai University of Traditional Chinese Medicine, Shanghai, China
- 2 Department of Anatomy and Cell Biology, University of Florida College of Medicine, Gainesville, FL, USA
- 6 E-institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, Shanghai, China
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2
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Hong S, Noh H, Teng Y, Shao J, Rehmani H, Ding HF, Dong Z, Su SB, Shi H, Kim J, Huang S. SHOX2 is a direct miR-375 target and a novel epithelial-to-mesenchymal transition inducer in breast cancer cells. Neoplasia 2014; 16:279-90.e1-5. [PMID: 24746361 DOI: 10.1016/j.neo.2014.03.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 03/17/2014] [Indexed: 01/22/2023] Open
Abstract
MicroRNAs have added a new dimension to our understanding of tumorigenesis and associated processes like epithelial-to-mesenchymal transition (EMT). Here, we show that miR-375 is elevated in epithelial-like breast cancer cells, and ectopic miR-375 expression suppresses EMT in mesenchymal-like breast cancer cells. We identified short stature homeobox 2 (SHOX2) as a miR-375 target, and miR-375-mediated suppression in EMT was reversed by forced SHOX2 expression. Ectopic SHOX2 expression can induce EMT in epithelial-like breast cancer cells, whereas SHOX2 knockdown diminishes EMT traits in mesenchymal-like breast cancer cells, demonstrating SHOX2 as an EMT inducer. We show that SHOX2 acts as a transcription factor to upregulate transforming growth factor β receptor I (TβR-I) expression, and TβR-I inhibitor LY364947 abolishes EMT elicited by ectopic SHOX2 expression, suggesting that transforming growth factor β signaling is essential for SHOX2-induced EMT. Manipulating SHOX2 abundance in breast cancer cells impact in vitro invasion and in vivo dissemination. Analysis of breast tumor microarray database revealed that high SHOX2 expression significantly correlates with poor patient survival. Our study supports a critical role of SHOX2 in breast tumorigenicity.
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Affiliation(s)
- Sungguan Hong
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Hyangsoon Noh
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Yong Teng
- Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Jing Shao
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Hina Rehmani
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Han-Fei Ding
- Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Zheng Dong
- Department of Anatomy and Cell Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA
| | - Shi-Bing Su
- Research Center for Traditional Chinese Medicine Complexity System and E-institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, Shanghai, China
| | - Huidong Shi
- Cancer Center, Georgia Regents University, Augusta, GA, USA
| | - Jaejik Kim
- Department of Biostatistics, Georgia Regents University, Augusta, GA, USA
| | - Shuang Huang
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Regents University, Augusta, GA, USA; Research Center for Traditional Chinese Medicine Complexity System and E-institute of Shanghai Municipal Education Committee, Shanghai University of Traditional Chinese Medicine, Shanghai, China.
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3
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Hong S, Noh H, Chen H, Padia R, Pan ZK, Su SB, Jing Q, Ding HF, Huang S. Signaling by p38 MAPK stimulates nuclear localization of the microprocessor component p68 for processing of selected primary microRNAs. Sci Signal 2013; 6:ra16. [PMID: 23482664 DOI: 10.1126/scisignal.2003706] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The importance of microRNAs (miRNAs) in biological and disease processes necessitates a better understanding of the mechanisms that regulate miRNA abundance. We showed that the activities of the mitogen-activated protein kinase (MAPK) p38 and its downstream effector kinase MAPK-activated protein kinase 2 (MK2) were necessary for the efficient processing of a subset of primary miRNAs (pri-miRNAs). Through yeast two-hybrid screening, we identified p68 (also known as DDX5), a key component of the Drosha complex that processes pri-miRNAs, as an MK2-interacting protein, and we found that MK2 phosphorylated p68 at Ser(197) in cells. In wild-type mouse embryonic fibroblasts (MEFs) treated with a p38 inhibitor or in MK2-deficient (MK2(-/-)) MEFs, expression of a phosphomimetic mutant p68 fully restored pri-miRNA processing, suggesting that MK2-mediated phosphorylation of p68 was essential for this process. We found that, whereas p68 was present in the nuclei of wild-type MEFs, it was found mostly in the cytoplasm of MK2(-/-) MEFs. Nuclear localization of p68 depended on MK2-mediated phosphorylation of Ser(197). In addition, inhibition of p38 MAPK promoted the growth of wild-type MEFs and breast cancer MCF7 cells by enhancing the abundance of c-Myc through suppression of the biogenesis of the miRNA miR-145, which targets c-Myc. Because pri-miRNA processing occurs in the nucleus, our findings suggest that the p38 MAPK-MK2 signaling pathway promotes miRNA biogenesis by facilitating the nuclear localization of p68.
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Affiliation(s)
- Sungguan Hong
- Department of Biochemistry and Molecular Biology, Medical College of Georgia, Georgia Health Sciences University, Augusta, GA 30912, USA.
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4
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Hu Q, Lu YY, Noh H, Hong S, Dong Z, Ding HF, Su SB, Huang S. Interleukin enhancer-binding factor 3 promotes breast tumor progression by regulating sustained urokinase-type plasminogen activator expression. Oncogene 2012; 32:3933-43. [PMID: 22986534 PMCID: PMC3819929 DOI: 10.1038/onc.2012.414] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2012] [Revised: 07/25/2012] [Accepted: 07/25/2012] [Indexed: 12/21/2022]
Abstract
Sustained urokinase-type plasminogen activator (uPA) expression is detected in aggressive breast tumors. Although uPA can be transiently upregulated by diverse extracellular stimuli, sustained, but not transiently upregulated uPA expression contributes to breast cancer invasion/metastasis. Unfortunately, how sustained uPA expression is achieved in invasive/metastatic breast cancer cells is unknown. Here, we show that sustained and transiently upregulated uPA expression are regulated by distinct mechanisms. Using a collection of transcription factor-targeted small-interfering RNAs, we discovered that interleukin enhancer-binding factor 3 (ILF3) is required for sustained uPA expression. Two discrete mechanisms mediate ILF3 action. The first is that ILF3 activates uPA transcription by binding to the CTGTT sequence in the nucleotides -1004∼-1000 of the uPA promoter; the second is that ILF3 inhibits the processing of uPA mRNA-targeting primary microRNAs (pri-miRNAs). Knockdown of ILF3 led to significant reduction in in vitro cell growth/migration/invasion and in vivo breast tumor development. Importantly, immunohistochemistry (IHC) showed that nuclear ILF3, but not cytoplasmic ILF3 staining correlates with elevated uPA level and higher grades of human breast tumor specimens. Nuclear localization of ILF3 highlights the role of ILF3 in sustained uPA expression as a transcription activator and pri-miRNA processing blocker. In conclusion, this study shows that ILF3 promotes breast tumorigenicity by regulating sustained uPA expression.
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Affiliation(s)
- Q Hu
- Department of Biochemistry and Molecular Biology, Georgia Health Sciences University, Augusta, GA 30912, USA
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Wang H, Chakrabarty S. Requirement of protein kinase Calpha, extracellular matrix remodeling, and cell-matrix interaction for transforming growth factorbeta-regulated expression of E-cadherin and catenins. J Cell Physiol 2001; 187:188-95. [PMID: 11267998 DOI: 10.1002/jcp.1068] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A hallmark of transforming growth factorbeta (TGFbeta) action is the induction of the synthesis and secretion of extracellular-matrix adhesion molecules and induction of the cell-surface expression of integrin receptors for these molecules (termed extracellular-matrix remodeling). The signal pathways leading to extracellular-matrix remodeling and the significance of extracellular-matrix remodeling in TGFbeta function is not well-understood. In the epithelium-derived human colon cancer cell line Moser, TGFbeta induces extracellular-matrix remodeling in a protein kinase Calpha-dependent manner. In this study we showed that TGFbeta was a potent inducer of the homotypic cell-cell adhesion molecule E-cadherin and its undercoat-associated proteins, the catenins and dramatically increased the amount of E-cadherin/gamma-catenin complex formation. We found that the induction of E-cadherin and alpha- and beta-catenin by TGFbeta was also dependent on protein kinase Calpha, whereas the induction of gamma-catenin was independent of protein kinase Calpha but dependent on other protein kinase C isoforms. We also found that protein kinase Calpha-dependent induction of extracellular-matrix remodeling and subsequent cell-matrix interaction requiring both fibronectin and laminin were a prerequisite for the induction of E-cadherin (and alpha- and beta-catenin but not gamma-catenin) by TGFbeta. We therefore concluded that two signal pathways exist in TGFbeta-regulated expression of E-cadherin and the catenins. We also concluded that a functional significance of TGFbeta-induced extracellular matrix remodeling is the activation of signal transduction mechanisms through increased interaction between extracellular matrix fibronectin and laminin and their cell-surface integrin receptors, which lead to the induction of E-cadherin (and alpha- and beta-catenin).
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Affiliation(s)
- H Wang
- Division of Pathology and Laboratory Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas, USA
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6
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Chakrabarty S, Liu BR, Rajagopal S. Disruption of transforming growth factor beta-regulated laminin receptor function by expression of antisense laminin, a chain RNA in human colon cancer cells. J Cell Physiol 2001; 186:47-52. [PMID: 11147813 DOI: 10.1002/1097-4652(200101)186:1<47::aid-jcp1009>3.0.co;2-a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Transforming growth factor beta1 (TGFbeta) simultaneously induces the expression of fibronectin, fibronectin receptor, laminin, and laminin receptor (alpha6beta1 integrin) in the human colon cancer cell line Moser (Int J Cancer, 57:742, 1994). Induction of fibronectin and induction of fibronectin receptor by TGFB are tightly coupled, and disrupting fibronectin induction disrupts the induction of fibronectin receptor and cellular adhesion to fibronectin (J Cellular Physiol, 170:138, 1997). We recently demonstrated the efficacy of using antisense chain-specific laminin RNA expression vectors to disrupt the induction by TGFP of the multichain laminin molecule (J Cellular Physiol, 178:296, 1999). We now show in this report that Moser cells used alpha6 and beta1 integrins to adhere to laminin, and, as is the fibronectin and fibronectin receptor system, disrupting the induction by TGFbeta of the ligand laminin by the expression of antisense laminin A chain RNA disrupted the induction of 125I-laminin binding and cellular adhesion to laminin. Disrupting laminin induction also blocked the induction of alpha6 and beta1 integrin laminin receptor by TGFbeta. We conclude that disrupting the induction of the ligand laminin by TGFbeta disrupts TGFbeta-regulated laminin receptor function by suppressing the induction of alpha6 and beta1 integrins. Therefore, targeted disruption of the ligand laminin may be an effective means in disrupting the function of both the ligand and its receptor in cells that utilize the laminin and laminin receptor system in malignant cell behavior.
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Affiliation(s)
- S Chakrabarty
- Division of Pathology and Laboratory Medicine, The University of Texas M.D. Anderson Cancer Center, Houston 77030, USA.
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Huang S, New L, Pan Z, Han J, Nemerow GR. Urokinase plasminogen activator/urokinase-specific surface receptor expression and matrix invasion by breast cancer cells requires constitutive p38alpha mitogen-activated protein kinase activity. J Biol Chem 2000; 275:12266-72. [PMID: 10766865 DOI: 10.1074/jbc.275.16.12266] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Overexpression of urokinase plasminogen activator (uPA) and its receptor (uPAR) has been well documented in a wide variety of tumor cells. In breast cancer, expression of uPA/uPAR is essential for tumor cell invasion and metastasis. However, the mechanism responsible for uPA/uPAR expression in cancer cells remains unclear. In the studies reported here, we show that endogenous p38 MAPK activity correlates well with breast carcinoma cell invasiveness. Treatment of highly invasive BT549 cells with a specific p38 MAPK inhibitor SB203580 diminished both uPA/uPAR mRNA and protein expression and abrogated the ability of these cells to invade matrigel, suggesting that p38 MAPK signaling pathway is involved in the regulation of uPA/uPAR expression and breast cancer cell invasion. We also demonstrated that SB203580-induced reduction in uPA/uPAR mRNA expression resulted from the de- stabilization of uPA and uPAR mRNA. Finally, by selectively inhibiting p38alpha or p38beta MAPK isoforms, we demonstrate that p38alpha, rather than p38beta, MAPK activity is essential for uPA/uPAR expression. These studies suggest that p38alpha MAPK signaling pathway is important for the maintenance of breast cancer invasive phenotype by promoting the stabilities of uPA and uPAR mRNA.
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Affiliation(s)
- S Huang
- Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA.
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Huang S, Stupack D, Liu A, Cheresh D, Nemerow GR. Cell growth and matrix invasion of EBV-immortalized human B lymphocytes is regulated by expression of alpha(v) integrins. Oncogene 2000; 19:1915-23. [PMID: 10773881 DOI: 10.1038/sj.onc.1203509] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
alpha(v) integrins have been shown to play an important role in epithelial-derived cell migration, cell growth and tumor invasion/metastasis, however their role on cells of hematopoietic origin is less clear. Epstein-Barr virus (EBV), a human herpesvirus associated with several lymphoproliferative disorders in man, induces expression of alpha(v) integrins on transformed B lymphocytes. In the studies reported here, we show that EBV infection increases alpha(v), beta3 and beta5 integrin subunit mRNAs as well as upregulates the expression of the alphavbeta3 integrin protein on human B cells. Among the nine different EBV proteins expressed in latently infected B cells (nuclear and plasma membrane-associated), only LMP1, LMP2A and EBNA2 were shown to selectively transactivate the alpha(v) integrin promoter. Treatment of EBV-transformed B cells with alpha(v) antisense oligonucleotides specifically reduced cell surface expression of alpha(v) integrins, inhibited cell growth in low serum, reduced cell invasion in matrigels and decreased expression of metalloprotease, MMP9. These studies indicate that alpha(v) integrins play a significant role in EBV-induced B-lymphocyte proliferation and invasion. Strategies to interfere with alphav integrin expression and/or function may therefore be of potential value in the treatment of EBV-associated lymphoproliferative disorders.
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Affiliation(s)
- S Huang
- Department of Immunology, IMM19 The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California, CA 92037, USA
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Shiba H, Fujita T, Doi N, Nakamura S, Nakanishi K, Takemoto T, Hino T, Noshiro M, Kawamoto T, Kurihara H, Kato Y. Differential effects of various growth factors and cytokines on the syntheses of DNA, type I collagen, laminin, fibronectin, osteonectin/secreted protein, acidic and rich in cysteine (SPARC), and alkaline phosphatase by human pulp cells in culture. J Cell Physiol 1998; 174:194-205. [PMID: 9428806 DOI: 10.1002/(sici)1097-4652(199802)174:2<194::aid-jcp7>3.0.co;2-j] [Citation(s) in RCA: 96] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study is to differentiate roles of several growth factors and cytokines in proliferation and differentiation of pulp cells during development and repair. In human pulp cell cultures, laminin and type I collagen levels per cell remained almost constant during the whole culture period (22 days). On the other hand, secreted protein, acidic and rich in cysteine (SPARC/osteonectin) and alkaline phosphatase (ALPase) levels markedly increased after the cultures reached confluence. Laminin and type I collagen, as well as fibronectin, stimulated the spreading of pulp cells within 1 h. Adding transforming growth factor-beta (TGF-beta) decreased laminin and ALPase levels, whereas it increased SPARC and fibronectin levels 3- to 10-fold. Western and Northern blots showed that TGF-beta enhanced SPARC synthesis at the protein and mRNA levels. Basic fibroblast growth factor (bFGF) decreased type I collagen, laminin, SPARC, and ALPase levels without changing the fibronectin level. Platelet-derived growth factor (PDGF) selectively decreased laminin, SPARC, and ALPase levels. Epidermal growth factor (EGF) also decreased SPARC and ALPase levels. Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) decreased type I collagen and laminin levels, and abolished SPARC and ALPase syntheses. Of these peptides, bFGF and PDGF showed the greatest stimulation of [3H]thymidine incorporation into DNA. TGF-beta, EGF, and TNF-alpha had less effect on DNA synthesis, whereas IL-1beta inhibited DNA synthesis. These findings demonstrated that TGF-beta, bFGF, EGF, PDGF, TNF-alpha, and IL-1beta have characteristically different patterns of actions on DNA, laminin, type I collagen, fibronectin, ALPase, and SPARC syntheses by pulp cells.
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Affiliation(s)
- H Shiba
- Department of Endodontology and Periodontology, Hiroshima University School of Dentistry, Japan
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