Flutamide inhibits nifedipine‐ and interleukin‐1β‐induced collagen overproduction in gingival fibroblasts

Lu H‐K, Tseng C‐C, Lee Y‐H, Li C‐L, Wang L‐F. Flutamide inhibits nifedipine‐ and interleukin‐1β‐induced collagen overproduction in gingival fibroblasts. J Periodont Res 2010; 45: 451–457. © 2010 John Wiley & Sons A/S Background and Objective: To understand the role of the androgen receptor in gingival overgrowth, the effects of flutamide on interleukin‐1β‐ and nifedipine‐induced gene expression of connective tissue growth factor (CTGF/CCN2) and collagen production in gingival fibroblasts were examined. Material and Methods: Gingival fibroblasts from healthy subjects and patients with dihydropyridine‐induced gingival overgrowth (DIGO) were used. Confluent cells were treated with nifedipine, interleukin‐1β or both. The mRNA expression was examined using real‐time polymerase chain reaction, and the concentration of total soluble collagen in conditioned media was analysed by Sircol Collagen Assay. In addition, the protein expressions of androgen receptor, CTGF/CCN2 and type I collagen in gingival tissue were determined by western blot. Results: Interleukin‐1β was more potent than nifedipine in stimulating CTGF/CCN2 and procollagen α1(I) mRNA expression, and there was an additive effect of the two drugs. Healthy cells exhibited an equal or stronger response of procollagen α1(I) than those with DIGO, but DIGO cells displayed a stronger response in the secretion of soluble collagen in the same conditions. Flutamide, an androgen receptor antagonist, inhibited stimulation by nifedipine or interleukin‐1β. Additionally, the protein expressions of androgen receptor and type I collagen were higher in DIGO gingival tissue than those in healthy gingival tissue. Conclusion: The data suggest that both nifedipine and interleukin‐1β play an important role in DIGO via androgen receptor upregulation and that gingival overgrowth is mainly due to collagen accumulation. Flutamide decreases the gene expression and protein production of collagen from dihydropyridine‐induced overgrowth cells.     

Differential expression of perlecan receptors, α‐dystroglycan and integrin β1, before and after invasion of oral squamous cell carcinoma

J Oral Pathol Med (2011) 40 : 552–559 Objectives: The deposition of perlecan, a heparan sulfate proteoglycan, is enhanced within oral carcinoma in situ (CIS) foci, while it dynamically switches from CIS foci to the stromal space in squamous cell carcinoma (SCC). Because α‐dystroglycan and integrin β1 have been identified as two of the perlecan receptors, we wanted to determine their differential distributions before and after invasion of oral SCC. Methods: Eighty‐two surgical tissue specimens of oral SCC containing different precancerous stages were examined by immunohistochemistry for perlecan, α‐dystroglycan, integrin β1, and Ki‐67. In addition, α‐dystroglycan mRNA signals were localized by in situ hybridization. Results: In normal epithelia, α‐dystroglycan and integrin β1 were localized on the cell membrane of basal cells, while perlecan was faintly present in the intercellular spaces of parabasal cells. In epithelial dysplasia and CIS, α‐dystroglycan and perlecan were well co‐localized in the epithelial layer, especially in its lower half, and this co‐localization was mostly overlapped with Ki‐67‐positive (+) cell zones. However, in SCC, α‐dystroglycan was localized neither within carcinoma cell nests nor in the stroma, while perlecan disappeared from SCC foci but emerged in the stromal space, leaving integrin β1+ and Ki‐67+ cells only to the periphery of SCC foci. α‐Dystroglycan mRNA signals were basically identical to the α‐dystroglycan protein localizations. Conclusion: The findings suggest that α‐dystroglycan and integrin β1 act as perlecan receptors in oral precancerous lesions prior to invasion, and that the perlecan signals via the two different receptors function in cellular differentiation and proliferation of CIS cells, respectively.     

Loss of human β‐defensin 1, 2, and 3 expression in oral squamous cell carcinoma

Introduction: Human β‐defensins (HBDs) are cationic, antimicrobial peptides produced by epithelial cells and involved in various aspects of the innate and acquired immune responses. They are expressed by oral tissues as constitutive and inducible genes. Recently, single nucleotide polymorphisms (SNPs) of β‐defensins have been correlated with increased susceptibility to certain diseases. Studies have reported altered expression of β‐defensins in cancers suggesting their involvement in carcinogenesis. The purpose of this study was to evaluate the regulation of HBD‐1 (also published as DEFB1), HBD‐2 (DEFB4) and HBD‐3 (DEFB103A) ( http://www.genenames.org/index.html ) and HBD‐1 SNPs in oral squamous cell carcinoma cell lines (OSCC) and healthy gingival keratinocytes. Methods: β‐defensin expression was quantitatively assessed using real‐time polymerase chain reactions in OSCC and control cell lines after exposure to interleukin‐1β, tumor necrosis factor‐α, and interferon‐γ. Control data were obtained in a previous study. DNA from 19 OSCC cell lines and 44 control subjects were extracted and the HBD‐1 region spanning the 5′ untranslated region to the first intron was sequenced and analysed for SNP identification and distribution. Results: HBD‐1 and HBD‐2 basal messenger RNA expression were significantly lower in OSCC. In addition, the ability to be induced was significantly reduced in OSCC for all three β‐defensins. Four HBD‐1 SNPs were differentially distributed between cancer and control populations. Genotype distribution at the HBD‐1 locus also suggested loss of heterozygosity in OSCC. Conclusions: The genetic variation observed in OSCC compared with that in control cell lines may account for differences in β‐defensin expression. These results suggest a putative role for β‐defensins in carcinogenesis and indicate that β‐defensins may be useful markers of OSCC.     

Phospholipase C‐γ1 expression correlated with cancer progression of potentially malignant oral lesions

Background: Phospholipase C‐γ1 (PLCγ1) is required for cellular migration during tumor progression and invasion of oral squamous cell carcinoma (OSCC) cells. The objective of the current study was to determine immunoexpression pattern of PLCγ1 in oral potentially malignant lesions (OPLs) and evaluate PLCγ1 usefulness as a biomarker for predicting clinical behavior in the carcinogenesis of OPL. Methods: In a retrospective follow‐up study, the expression pattern of PLCγ1 protein was determined using immunohistochemistry in samples from 68 patients, including untransformed cases (n = 38) and malignant‐transformed cases (n = 30). The corresponding post‐malignant lesions (OSCCs) were also performed. Results: We observed that elevated expression of PLCγ1 in 40 of 68 (59%) general OPLs and 23 of 30 (77%) OSCCs compared with that in normal oral mucosa. Kaplan–Meier analysis revealed that patients with PLCγ1 positivity had a significantly higher incidence of OSCC than those with PLCγ1 negativity. Cox regression analysis revealed that PLCγ1 expression patterns were significantly associated with increased risk of malignant progression. In addition, the correlation between PLCγ1 expression in pre‐malignant OPL and that in post‐malignant OSCC was significant (P = 0.004). Conclusion: These data indicate that PLCγ1 expression in OPL correlated with oral cancer progression, and PLCγ1 may serve as a useful marker for the identification of high‐risk OPL into OSCC.     

Hypoxia inducible factor‐1α expression in areca quid chewing‐associated oral squamous cell carcinomas

Oral Diseases (2010) 16 , 696–701 Objectives: Hypoxia inducible factor (HIF)‐1α gene expression is mainly induced by tissue hypoxia. Overexpression of HIF‐1α has been demonstrated in a variety of cancers. The aim of this study was to compare HIF‐1α expression in normal human oral epithelium and areca quid chewing‐associated oral squamous cell carcinoma (OSCC) and further to explore the potential mechanisms that may lead to induce HIF‐1α expression. Methods: Twenty‐five OSCC from areca quid chewing‐associated OSCC and 10 normal oral tissue biopsy samples without areca quid chewing were analyzed by immunohistochemistry. The oral epithelial cell line GNM cells were challenged with arecoline, a major areca nut alkaloid, by using Western blot analysis. Furthermore, glutathione precursor N‐acetyl‐l ‐cysteine (NAC), AP‐1 inhibitor curcumin, extracellular signal‐regulated protein kinase inhibitor PD98059, and protein kinase C inhibitor staurosporine were added to find the possible regulatory mechanisms. Results: Hypoxia inducible factor‐1α expression was significantly higher in OSCC specimens than normal specimen (P < 0.05). Arecoline was found to elevate HIF‐1α expression in a dose‐ and time‐dependent manner (P < 0.05). The addition of NAC, curcumin, PD98059, and staurosporine markedly inhibited the arecoline‐induced HIF‐1α expression (P < 0.05). Conclusions: Hypoxia inducible factor‐1α expression is significantly upregulated in areca quid chewing‐associated OSCC and HIF‐1α expression induced by arecoline is downregulated by NAC, curcumin, PD98059, and staurosporine.     

Effects of interleukin‐1β and tumor necrosis factor‐α on macrophage inflammatory protein‐3α production in synovial fibroblast‐like cells from human temporomandibular joints

Background

Interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast‐like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL‐1β or TNF‐α to determine which genes were altered.

Methods

Ribonucleic acid was isolated from SFCs after IL‐1β or TNF‐α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein‐3α (MIP‐3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL‐1β or TNF‐α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL‐1β or TNF‐α after treatment with inhibitors. The MIP‐3α levels were measured using an ELISA.

Results

Macrophage inflammatory protein‐3α was the gene most upregulated by IL‐1β‐ or TNF‐α stimulation. The mRNA and protein levels of MIP‐3α increased in response to IL‐1β in a time‐dependent manner. In contrast, during TNF‐α stimulation, the MIP‐3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL‐1β‐ and TNF‐α‐stimulated MIP‐3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors.

Conclusion

Interleukin‐1β and TNF‐α increased the MIP‐3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP‐3α from stimulation with IL‐1β or TNF‐α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.     

The expressions of IGF‐1, BMP‐2 and TGF‐β1 in cartilage of condylar hyperplasia

Summary Condylar hyperplasia is a complex post‐natal growth abnormality of the mandible and condyle, which leads to facial asymmetry. We investigated the distributions of insulin‐like growth factors (IGF‐1), bone morphogenetic protein‐2 (BMP‐2) and transforming growth factor‐β1 (TGF‐β1) in cartilage of condylar hyperplasia and revealed relationships between age and the cartilaginous thickness. Twenty patients with condylar hyperplasia were divided into four histopathological types. The cartilaginous thickness and age in different histological types were analysed, and the localizations of IGF‐1, BMP‐2 and TGF‐β1 were detected by immunohistochemistry analysis. The cartilaginous thickness of condylar hyperplasia significantly increased. The cartilaginous thickness of type III was significantly thicker than type I and type II, Bivariate correlation revealed a significant correlations between age and the cartilaginous thickness (r = 0·68, P = 0·01). However, the expressions of IGF‐1, BMP‐2 and TGF‐β1 were the strongest in type I. In almost all types of condylar hyperplasia, the presence of IGF‐1 and BMP‐2 was found mainly in the proliferative chondrocyte layer and the hypertrophic chondrocyte layer, and only a few in the calcified chondrocyte layer. The presence of TGF‐β1 widely distributed from the fibrous articular surface to the calcified cartilage. These findings suggest that the proliferative activity of cartilage in condylar hyperplasia is strongly associated with age and cartilaginous thickness. Therefore, the four pathological types of condylar hyperplasia seem more likely to be four discontinuous stages.     

Utilization and acid production of β‐galactosyllactose by oral streptococci and human dental plaque

β‐Galactosyllactose is a trisaccharide containing the β‐galactosidic linkage at the nonreducing end. The purpose of this study was to determine whether certain oral streptococci could utilize four kinds of β‐galactosyllactoses. Three of four β‐galactosyllactoses were unable to support growth of the oral streptococci and to be a substrate for producing acid from the cell suspensions and dental plaque. 4′‐β‐Galactosyllactose supported growth of Streptococcus sanguis ATCC 35105, ATCC 49298, Streptococcus mitis ATCC 15914, Streptococcus oralis ATCC 35037, ATCC 10557 and Streptococcus milleri 10707 and produced acid from dental plaque. Although β‐galactosidase activities were observed in all the strains, 4′‐β‐galactosyllactose could not be used as a carbon source for the growth of mutans streptococci. Enzymes metabolizing 4′‐β‐galactosyllactose were induced when S. oralis ATCC 10557 was cultured in medium containing galactose. These results suggested that 4′‐β‐galactosyllactose could be as cariogenic as lactose if it is consumed frequently and retained for a long period in the mouth.     

Down‐regulation of interleukin‐1α‐induced matrix metalloproteinase‐13 expression via EP1 receptors by prostaglandin E2 in human periodontal ligament cells

In the present study, we investigated the effect of prostaglandin (PG) E₂ on matrix metalloproteinase (MMP)‐13 production in human periodontal ligament cells stimulated with interleukin (IL)‐1α. IL‐1α enhanced both MMP‐13 and PGE₂ production. Indomethacin, a nonselective cyclooxygenase inhibitor, and NS‐398, a specific cyclooxygenase‐2 (COX‐2) inhibitor, significantly enhanced IL‐1α‐induced MMP‐13 production in periodontal ligament cells, although both the agents completely inhibited IL‐1α‐induced PGE₂ production. Exogenous PGE₂ reduced IL‐1α‐induced MMP‐13 mRNA and protein production in a dose‐dependent manner. 17‐phenyl‐ω‐trinor PGE₂, a selective EP₁ receptor agonist, mimicked the inhibitory effect of PGE₂ on IL‐1α‐induced MMP‐13 mRNA and protein production. On the basis of these data, we suggest that COX‐2‐dependent PGE₂ down‐regulates IL‐1α‐elicited MMP‐13 production via EP₁ receptors in human periodontal ligament cells. PGE₂ may be involved in the regulation of destruction of extracellular matrix components in periodontal lesions.