Surgical treatment of gingival overgrowth with 10 years of follow-up

<p>Abstract</p> <p>Background</p> <p>In some pathological conditions, gingivitis caused by plaque accumulation can be more severe, with the result of an overgrowth. Nevertheless, the overgrowth involves the gingival margin with extension to the inter-dental papilla. The lesion may involve the inter-proximal spaces, and become so extensive that the teeth are displaced and their crowns covered. Severe overgrowth may lead to impairment in aesthetic and masticatory functions, requiring surgical excision of the excessive tissue. Aim of this study is to describe an operative protocol for the surgical treatment of localized gingival overgrowth analyzing the surgical technique, times and follow-up.</p> <p>Methods</p> <p>A total of 20 patients were enrolled and underwent initial, non surgical, periodontal treatment and training sessions on home oral hygiene training. The treatment plan involved radical exeresis of the mass followed by positioning of an autograft of connective tissue and keratinized gingiva.</p> <p>Results</p> <p>During 10 years of follow-up, all the grafts appeared well vascularized, aesthetically satisfactory, and without relapse.</p> <p>Conclusions</p> <p>Periodontal examinations, surgical procedures, and dental hygiene with follow-up are an essential part of the treatment protocol. However, additional effort is needed from the patient. Hopefully, the final treatment result makes it all worthwhile.</p

Blimp1 Activation by AP-1 in Human Lung Cancer Cells Promotes a Migratory Phenotype and Is Inhibited by the Lysyl Oxidase Propeptide

B lymphocyte-induced maturation protein 1 (Blimp1) is a master regulator of B cell differentiation, and controls migration of primordial germ cells. Recently we observed aberrant Blimp1 expression in breast cancer cells resulting from an NF-κB RelB to Ras signaling pathway. In order to address the question of whether the unexpected expression of Blimp1 is seen in other epithelial-derived tumors, we selected lung cancers as they are frequently driven by Ras signaling. Blimp1 was detected in all five lung cancer cell lines examined and shown to promote lung cancer cell migration and invasion. Interrogation of microarray datasets demonstrated elevated BLIMP1 RNA expression in lung adenocarcinoma, pancreatic ductal carcinomas, head and neck tumors as well as in glioblastomas. Involvement of Ras and its downstream kinase c-Raf was confirmed using mutant and siRNA strategies. We next addressed the issue of mechanism of Blimp1 activation in lung cancer. Using knockdown and ectopic expression, the role of the Activator Protein (AP)-1 family of transcription factors was demonstrated. Further, chromatin immunoprecipitation assays confirmed binding to identified AP-1 elements in the BLIMP1 promoter of ectopically expressed c-Jun and of endogenous AP-1 subunits following serum stimulation. The propeptide domain of lysyl oxidase (LOX-PP) was identified as a tumor suppressor, with ability to reduce Ras signaling in lung cancer cells. LOX-PP reduced expression of Blimp1 by binding to c-Raf and inhibiting activation of AP-1, thereby attenuating the migratory phenotype of lung cancer cells. Thus, Blimp1 is a mediator of Ras/Raf/AP-1 signaling that promotes cell migration, and is repressed by LOX-PP in lung cancer

Autocrine growth factor regulation of lysyl oxidase expression in transformed fibroblasts.

International audienceLysyl oxidase catalyzes oxidative deamination of peptidyl-lysine and hydroxylysine residues in collagens and lysine residues in elastin to form peptidyl aldehydes that are required for the formation of covalent cross-links in normal extracellular matrix biosynthesis. Lysyl oxidase in addition has tumor suppressor activity, and phenotypic reversion of transformed cell lines is accompanied by increased lysyl oxidase expression. The mechanism of low expression of lysyl oxidase in tumor cells is unknown. The present study investigates the hypothesis that autocrine growth factor pathways maintain low lysyl oxidase expression levels in c-H-ras-transformed fibroblasts (RS485 cell line). Autocrine pathways were blocked with suramin, a general inhibitor of growth factor receptor binding, and resulted in more than a 10-fold increase in lysyl oxidase expression and proenzyme production. This regulation was found to be reversible and occurred at the transcriptional level determined using lysyl oxidase promoter/reporter gene assays. Function blocking anti-fibroblast growth factor-2 (FGF-2) antibody enhanced lysyl oxidase expression in the absence of suramin. Finally, the addition of FGF-2 to suramin-treated cells completely reversed suramin stimulation of lysyl oxidase mRNA levels. Data support that an FGF-2 autocrine pathway inhibits lysyl oxidase transcription in the tumorigenic-transformed RS485 cell line. This finding may be of therapeutic significance and, in addition, provides a new experimental approach to investigate the mechanism of the tumor suppressor activity of lysyl oxidase.Lysyl oxidase catalyzes oxidative deamination of peptidyl-lysine and hydroxylysine residues in collagens and lysine residues in elastin to form peptidyl aldehydes that are required for the formation of covalent cross-links in normal extracellular matrix biosynthesis. Lysyl oxidase in addition has tumor suppressor activity, and phenotypic reversion of transformed cell lines is accompanied by increased lysyl oxidase expression. The mechanism of low expression of lysyl oxidase in tumor cells is unknown. The present study investigates the hypothesis that autocrine growth factor pathways maintain low lysyl oxidase expression levels in c-H-ras-transformed fibroblasts (RS485 cell line). Autocrine pathways were blocked with suramin, a general inhibitor of growth factor receptor binding, and resulted in more than a 10-fold increase in lysyl oxidase expression and proenzyme production. This regulation was found to be reversible and occurred at the transcriptional level determined using lysyl oxidase promoter/reporter gene assays. Function blocking anti-fibroblast growth factor-2 (FGF-2) antibody enhanced lysyl oxidase expression in the absence of suramin. Finally, the addition of FGF-2 to suramin-treated cells completely reversed suramin stimulation of lysyl oxidase mRNA levels. Data support that an FGF-2 autocrine pathway inhibits lysyl oxidase transcription in the tumorigenic-transformed RS485 cell line. This finding may be of therapeutic significance and, in addition, provides a new experimental approach to investigate the mechanism of the tumor suppressor activity of lysyl oxidase

Inhibition of CIN85-mediated invasion by a novel SH3 domain binding motif in the lysyl oxidase propeptide

The lysyl oxidase gene inhibits Ras signaling in transformed fibroblasts and breast cancer cells. Its activity was mapped to the 162 amino acid propeptide domain (LOX-PP) of the lysyl oxidase precursor protein. LOX-PP inhibited the Her-2/Ras signaling axis in breast cancer cells, and reduced the Her-2-driven breast tumor burden in a xenograft model. Since its mechanism of action is largely unknown, co-affinity-purification/mass spectrometry was performed and the “Cbl-interacting protein of 85-kDa” (CIN85) identified as an associating protein. CIN85 is an SH3-containing adapter protein that is overexpressed in invasive breast cancers. The CIN85 SH3 domains interact with c-Cbl, an E3 ubiquitin ligase, via an unconventional PxxxPR ligand sequence, with the highest affinity displayed by the SH3-B domain. Interaction with CIN85 recruits c-Cbl to the AMAP1 complex where its ubiquitination activity is necessary for cancer cells to develop an invasive phenotype and to degrade the matrix. Direct interaction of LOX-PP with CIN85 was confirmed using co-immunoprecipitation analysis of lysates from breast cancer cells and of purified expressed proteins. CIN85 interaction with c-Cbl was reduced by LOX-PP. Domain specific CIN85 regions and deletion mutants of LOX-PP were prepared and used to map the sites of interaction to the SH3-B domain of CIN85 and to an epitope encompassing amino acids 111 to 116 of LOX-PP. Specific LOX-PP point mutant proteins P111A and R116A failed to interact with CIN85 or to compete for CIN85 binding with c-Cbl. Structural modeling identified a new atypical PxpxxRh SH3-binding motif in this region of LOX-PP. The LOX-PP interaction with CIN85 was shown to reduce the invasive phenotype of breast cancer cells, including their ability to degrade the surrounding extracellular matrix and for Matrigel outgrowth. Thus, LOX-PP interacts with CIN85 via a novel SH3-binding motif and this association reduces CIN85-promoted invasion by breast cancer cells

The lysyl oxidase pro-peptide attenuates fibronectin-mediated activation of the focal adhesion kinase and p130Cas in breast cancer cells.

Abstract Abstract #4073 The lysyl oxidase (LOX) gene encodes an enzyme (LOX) critical for extracellular matrix maturation. The LOX gene has also been shown to inhibit the transforming activity of Ras oncogene signaling. In particular, the pro-peptide domain (LOX-PP) of the secreted precursor protein (Pro-LOX) was found to inhibit the transformed phenotype of breast, lung and pancreatic cancer cells. LOX-PP expression in these carcinoma cells reverted Her-2/neu- and Ras-mediated epithelial to mesenchymal transition (EMT), leading to increased expression of E-cadherin and γ-catenin, and reduced levels of Snail, vimentin and/or BCL2, as well as invasion through Matrigel. Furthermore, LOX-PP expression reduced tumor formation of Her-2/neu driven breast cancer cells in a xenograft model. However, the mechanism of action remains to be determined. Here the ability of LOX-PP to attenuate the integrin signaling pathway in NF639 breast cancer cells driven by Her-2/neu, which signals via Ras, was tested. Ectopic Pro-LOX and LOX-PP expression inhibited fibronectin-stimulated protein tyrosine phosphorylation. Importantly, phosphorylation of the focal adhesion kinase (FAK) on Tyr397 and Tyr576, and the activation of its downstream target p130Cas were substantially reduced. Furthermore, these changes were also reflected by a reduced amount of endogenous p130Cas in the Triton X-100 insoluble protein fraction, and attenuation of fibronectin-activated haptotaxis. Interestingly, expression of mature LOX enzyme enhanced fibronectin-stimulated integrin signaling. Of note, treatment with recombinant LOX-PP reduced haptotaxis of NF639 and human MDA-MB-231 and Hs578T breast cancer cells. Thus, the tumor suppressor function of LOX-PP is likely mediated, in part, by blocking integrin signaling and fibronectin-stimulated cell migration. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4073.</jats:p

The propeptide domain of lysyl oxidase induces phenotypic reversion of ras-transformed cells.

International audienceLysyl oxidase is an extracellular enzyme critical for the normal biosynthesis of collagens and elastin. In addition, lysyl oxidase reverts ras-mediated transformation, and lysyl oxidase expression is down-regulated in human cancers. Since suramin inhibits growth factor signaling pathways and induces lysyl oxidase in ras-transformed NIH3T3 cells (RS485 cells), we sought to investigate the effects of suramin on the phenotype of transformed cells and the role of lysyl oxidase in mediating these effects. Suramin treatment resulted in a more normal phenotype as judged by growth rate, cell cycle parameters, and morphology. beta-aminopropionitrile, the selective inhibitor of lysyl oxidase enzyme activity, was remarkably unable to block suramin-induced reversion. By contrast, ectopic antisense lysyl oxidase demonstrated that lysyl oxidase gene expression mediated phenotypic reversion. Since lysyl oxidase is synthesized as a 50 kDa precursor and processed to a 30 kDa active enzyme and 18 kDa propeptide, the effects of these two products on the transformed phenotype of RS485 cells were then directly assessed in the absence of suramin. Here we report, for the first time, that the lysyl oxidase propeptide, and not the lysyl oxidase enzyme, inhibits ras-dependent transformation as determined by effects on cell proliferation assays, growth in soft agar, and Akt-dependent induction of NF-kappaB activity. Thus, the lysyl oxidase propeptide, which is released during extracellular proteolytic processing of pro-lysyl oxidase, functions to inhibit ras-dependent cell transformation.Lysyl oxidase is an extracellular enzyme critical for the normal biosynthesis of collagens and elastin. In addition, lysyl oxidase reverts ras-mediated transformation, and lysyl oxidase expression is down-regulated in human cancers. Since suramin inhibits growth factor signaling pathways and induces lysyl oxidase in ras-transformed NIH3T3 cells (RS485 cells), we sought to investigate the effects of suramin on the phenotype of transformed cells and the role of lysyl oxidase in mediating these effects. Suramin treatment resulted in a more normal phenotype as judged by growth rate, cell cycle parameters, and morphology. beta-aminopropionitrile, the selective inhibitor of lysyl oxidase enzyme activity, was remarkably unable to block suramin-induced reversion. By contrast, ectopic antisense lysyl oxidase demonstrated that lysyl oxidase gene expression mediated phenotypic reversion. Since lysyl oxidase is synthesized as a 50 kDa precursor and processed to a 30 kDa active enzyme and 18 kDa propeptide, the effects of these two products on the transformed phenotype of RS485 cells were then directly assessed in the absence of suramin. Here we report, for the first time, that the lysyl oxidase propeptide, and not the lysyl oxidase enzyme, inhibits ras-dependent transformation as determined by effects on cell proliferation assays, growth in soft agar, and Akt-dependent induction of NF-kappaB activity. Thus, the lysyl oxidase propeptide, which is released during extracellular proteolytic processing of pro-lysyl oxidase, functions to inhibit ras-dependent cell transformation

Connective tissue growth factor in drug-induced gingival overgrowth

Background: Drug-induced gingival overgrowth is a known side effect of certain chemotherapeutic agents used for the treatment of systemic disorders. The pathogenesis and mechanisms responsible for this condition are not fully understood. This study assesses for the presence and localization of connective tissue growth factor (CTGF) in drug-induced gingival overgrowth tissues. CTGF immunostaining was compared with sections stained with transforming growth factor (TGF)-beta1 and CD31 antibodies in order to investigate possible pathogenic mechanisms