Downregulation of lysyl oxidase in cadmium-resistant fibroblasts.

Li, Wande; Chou, Iih‐Nan; Boak, Andra M.; Kagan, Herbert M.

doi:10.1165/ajrcmb.13.4.7546771

Cited by 17 publications

(20 citation statements)

References 22 publications

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“…Although the Western blot did not reveal the presence of the 50-kDa N-glycosylated proenzyme or the nonglycosylated 46-kDa form of the proenzyme (2), the possibility that pro-LO species may enter the nucleus and be rapidly converted to the mature 32-kDa catalyst is not presently excluded. However, because LO is synthesized as a preproprotein (2,19), it is expected to be directed by its signal peptide to enter the endoplasmic reticulum in preparation for secretion from the cell. Nevertheless, there are precedents for both extracellular and intranuclear distribution of products of preproproteins, including nucleoside triphosphatase associated with chromatin of pea nuclei (29) and fibroblast growth factor 3 (30).…”

Section: Discussionmentioning

confidence: 99%

“…Polyclonal anti-LO, previously shown to be specific for LO forms immunoprecipitated from vascular smooth muscle cells (2) and Swiss 3T3 fibroblasts (19), was raised in rabbits against pure 32-kDa bovine aorta LO (2). The antiserum was affinity-purified against purified bovine aorta LO (20) immobilized on agarose, according to the instructions provided with the AminoLink immobilization kit (Pierce Chemicals).…”

Section: Methodsmentioning

confidence: 99%

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Localization and activity of lysyl oxidase within nuclei of fibrogenic cells

Nellaiappan²,

Strassmaier³

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

155

120

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Lysyl oxidase (EC 1.4.3.13) oxidizes peptidyl lysine to peptidyl aldehyde residues within collagen and elastin, thus initiating formation of the covalent crosslinkages that insolubilize these extracellular proteins. Recent findings raise the possibility that this enzyme may also function intracellularly. The present study provides evidence by immunocytochemical confocal microscopy, Western blot analysis, enzyme assays, and chemical analyses for lysyl oxidase reaction products that this enzyme is present and active within rat vascular smooth muscle cell nuclei. Confocal microscopy indicates its presence within nuclei of 3T3 fibroblasts, as well.Lysyl oxidase (LO; EC 1.4.3.13) catalyzes the post-translational modification of elastin and collagen, by oxidizing selected lysine residues within these proteins to peptidyl ␣-aminoadipic-␦-semialdehyde. Subsequent spontaneous reactions of the peptidyl aldehydes yield covalent cross-linkages (1). LO is synthesized as a 46-kDa preproenzyme by fibrogenic cells. After signal peptide cleavage and N-glycosylation, the resulting 50-kDa N-glycosylated proenzyme is secreted (2) and proteolytically processed in the extracellular space to a mature enzyme of 31 Ϯ 1 kDa (3).Although initiation of the cross-linking of elastin and collagen is a critical function of LO, there is evidence that it may have additional biological roles. The mature enzyme isolated from bovine aorta is chemotactic for monocytes and lymphocytes in assays in vitro, with the chemotactic effect requiring a functional active site (4). Moreover, LO expression is negligibly low in several neoplastically transformed cell lines (5), including fibroblasts transformed with the Ha-ras oncogene (6, 7). It is of particular interest in this regard that a murine ras recision gene, the expression of which appears to suppress the tumorigenic effect of Ha-ras, encodes LO (6-9). The basis of this apparent effect of LO has yet to be understood. However, a recent report notes that transfection of revertants derived from ras-transformed NIH 3T3 cells with LO antisense but not LO sense constructs induced a change in the relatively ''loose'' chromatin packing state of the revertants to the tighter chromatin packing state of the original transformants (10). These results raise the possibility that LO may directly or indirectly exert effects on nuclear components. In the present study, we provide evidence that LO occurs and catalytically functions within the nuclei of fibrogenic cells. EXPERIMENTAL PROCEDURESCell Culture. Neonatal rat aorta smooth muscle cells (NRASMCs), explanted from 2-to 3-day-old rat pups as described (11, 12), were used in first passage at or just prior to confluency. Swiss 3T3 fibroblasts (American Type Culture Collection) were used at confluency after 3-4 days of culture in passages 9-12. Cells were cultured in DMEM containing 3.7 g of NaHCO 3 per l, 100 units of penicillin per ml, 100 g of streptomycin per ml, 0.1 mM nonessential amino acids, 1 mM sodium pyruvate (GIBCO͞BRL), and 10% fetal bovine serum ...

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Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Localization and activity of lysyl oxidase within nuclei of fibrogenic cells

Nellaiappan²,

Strassmaier³

et al. 1997

Proc. Natl. Acad. Sci. U.S.A.

155

120

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“…The catalytic activity of LOX is copper-dependent with the carboxyterminus requiring the presence of a tightly bound active copper (II) ion (30). Although copper availability does not directly affect synthesis, it does markedly influence its functional activity (31,32). Tetrathiomolybdate is a potent copper chelator and has demonstrated antiangiogenic, antifibrogenic, and anti-inflammatory actions in preclinical studies.…”

Section: Therapeutic Potential and Clinical Implications For Future Tmentioning

confidence: 99%

Lysyl Oxidase, a Targetable Secreted Molecule Involved in Cancer Metastasis

2016

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Secondary metastatic cancer remains the single biggest cause of mortality and morbidity across most solid tumors. In breast cancer, 100% of deaths are attributed to metastasis. At present, there are no "cures" for secondary metastatic cancer of any form and there is an urgent unmet clinical need to improve the tools available in our arsenal against this disease, both in terms of treatment, but also prevention. Recently, we showed that hypoxic induction of the extracellular matrix modifying enzyme lysyl oxidase (LOX) correlates with metastatic dissemination to the bone in estrogen receptor negative breast cancer and is essential for the formation of premetastatic osteolytic lesions. We showed that in models of breast cancer metastasis, targeting LOX, or its downstream effects, significantly inhibited premetastatic niche formation and the resulting metastatic burden, offering preclinical validation of this enzyme as a therapeutic target for metastatic breast cancer. Our work is the latest in an emerging body of work supporting the targeting of LOX and calls for greater efforts in developing therapeutics against this extracellular secreted factor in the prevention of cancer progression across multiple solid tumor types. Cancer Res; 76(2); 188-92. Ó2016 AACR. Cancer Metastasis and the Importance of the Cellular MicroenvironmentThe spread of primary tumors to nonadjacent unrelated organs has proven to be a complex and difficult problem for researchers to tackle. This is because metastasis is a systemic process involving not only primary tumor cells, but also contributions from a vast and diverse range of nonmalignant host cells at both primary and secondary sites over varying timescales.Over the last two decades, it has become increasingly apparent in the field of cancer research that the genetic aberrations once seen as the primary drivers of cancer initiation and metastasis, can account for only a subset of the necessary steps required for progression. Additional contributions from the tumor microenvironment, dictated by both the tumor cells themselves, but more importantly by resident nonmalignant cells, provide an enormous repertoire of both soluble and insoluble cues, which facilitate metastasis. The dissemination of an isolated (and often surgically resectable) primary tumor to full-blown metastatic disease is a complex and reciprocal process, and it is currently unclear whether tumor cells or the microenvironment drives progression or they act equally. The deposition and posttranslational modification, as well as remodeling of the local extracellular matrix (ECM) has been shown to be critically important in metastasis both at primary and secondary sites. Similarly, the secretomes of cancer cells (and recruited host cells) have also been shown to be key in controlling the recruitment and response of nonmalignant host cells within the primary tumor microenvironment generating both feed-forward and feed-back signaling loops.The idea that a tumor can modulate not only the behavior of local cells and the re...

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“…Swiss 3T3 fibroblasts, plated at 2-3 Â 10 5 cells per 60-mm dish, were cultured in 10% fetal bovine serum/Dulbecco's Modified Eagle's Medium (FBS/DMEM) for 20 h, growtharrested by incubation in 0.3% FBS/DMEM for 3 days, and then used for experiments as described [Li et al, 1995]. The NIH 3T3 IgBNM6-1 cell line [Rogelj et al, 1988[Rogelj et al, , 1989 used in this study overexpresses bFGF and was derived from NIH 3T3 fibroblasts which had been transfected with bFGF cDNA [Rogelj et al, 1988] encoding 18 kDa bFGF fused at its second amino acid residue to an amino terminal immunoglobulin signal peptide of 19 amino acids.…”

Section: Cell Culturementioning

confidence: 99%

“…Aliquots of the incubated reaction mixtures were analyzed by SDS-PAGE (15%) and autoradiography as described [Li et al, 1995]. For Western blot analysis of MAP kinase activation, control and treated cells were lysed in RIPA buffer [1% NP40, 0.5% sodium deoxycholate, 0.1% SDS, 1 mM phenylmethanesulfonyl fluoride in phosphate-buffered saline (PBS)] according to the instructions of the RIPA lysis kit (Santa Cruz BioTech, Santa Cruz, CA).…”

mentioning

confidence: 99%

Lysyl oxidase oxidizes basic fibroblast growth factor and inactivates its mitogenic potential

Nugent

Zhao

et al. 2002

J of Cellular Biochemistry

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Lysyl oxidase (LO) plays a central role in the crosslinking of collagen and elastin in the extracellular matrix. Here we demonstrate that basic fibroblast growth factor (bFGF), a polypeptide which regulates proliferation, differentiation, and migration of a variety of cell types, is a substrate of LO. The oxidation of lysine residues in bFGF by LO resulted in the covalent crosslinking of bFGF monomers to form dimers and higher order oligomers and dramatically altered its biological properties. Both the mitogenic potential and the nuclear localization of bFGF were markedly inhibited in the Swiss 3T3 cells upon its oxidation by LO. NIH 3T3 IgBNM 6-1 cells (6-1 cells) overexpress bFGF which participates in an autocrine mechanism accounting for the transformation of these cells into a tumorigenic state. Exposure of the 6-1 cells to nanomolar concentrations of LO in culture oxidized lysine and generated crosslinkages in bFGF within the cell and markedly reduced proliferative rates. The lack of LO expression has been correlated with hyperproliferative cell growth, while this enzyme has been identified as a suppressor of ras-induced tumorigenesis. The present results illustrate a mechanism by which LO can depress normal and transformed cell growth.

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Downregulation of lysyl oxidase in cadmium-resistant fibroblasts.

Cited by 17 publications

References 22 publications

Localization and activity of lysyl oxidase within nuclei of fibrogenic cells

Localization and activity of lysyl oxidase within nuclei of fibrogenic cells

Lysyl Oxidase, a Targetable Secreted Molecule Involved in Cancer Metastasis

Lysyl oxidase oxidizes basic fibroblast growth factor and inactivates its mitogenic potential

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