The inhibitory effects of immunosuppressive factors, dexamethasone and interleukin-4, on NF-kappaB-mediated protease production by oral cancer

RNA-based liposomes for oral cancer: From biophysical characterization to biological evaluation

Oral cancer incidence and mortality are increasing over time. The most common therapies for oral cancers are surgery and radiotherapy, either used alone or combined, and immunotherapy can be also an option. Although there are several therapeutic options, none of them are completely effective, and in addition, there are numerous associated side effects. To overcome these limitations, researchers have been trying to reduce these drawbacks by using drug delivery systems that carry drugs for specific delivery to cancer cells. For that purpose, RNA-coated liposomes to selectively deliver the ligands C8 (acridine orange derivative) and dexamethasone to oral cancer cells were produced, characterized, and biologically evaluated. Firstly, the RNA structure and binding interaction with ligands (C8 and dexamethasone) were evaluated by circular dichroism (CD), thermal difference spectroscopy (TDS), nuclear magnetic resonance (NMR) and fluorescence titrations. The biophysical assays evidenced the formation of an RNA hairpin and duplex structure. Moreover, steady-state and time-resolved fluorescence intensity and anisotropy experiments show that C8 forms a complex with RNA and adopts an open conformation upon RNA binding. Then, RNA-coated liposomes were characterized by dynamic light scattering, and diameters near 160 nm were observed. Time-resolved anisotropy measurements of C8 loaded in RNA-functionalized liposomes indicate the co-existence of free C8 in solution (inside the liposome) and C8 bound to RNA at the external liposome surface. The RNA-functionalized liposomes loaded with C8 or dexamethasone mediated a significant reduction in the cell viability of malignant UPCI-SCC-154 cells while maintaining viable non-malignant NHDF cells. Additionally, the liposomes were able to internalize the cells, with higher uptake by the malignant cell line. Overall, the results obtained in this work can contribute to the development of new drug delivery systems based on RNA-coated liposomes.

Is Systemic Immunosuppression a Risk Factor for Oral Cancer? A Systematic Review and Meta-Analysis

Even if the relationship between immunosuppression and increased incidence of systemic cancers is well known, there is less awareness about the risk of developing oral cancer in immunosuppressed patients. The aim of this review was to evaluate the association between immunosuppression and the development of oral cancer. Two authors independently and, in duplicate, conducted a systematic literature review of international journals and electronic databases (MEDLINE via OVID, Scopus, and Web of Science) from their inception to 28 April 2023. The assessment of risk of bias and overall quality of evidence was performed using the Newcastle-Ottawa Scale and GRADE system. A total of 2843 articles was identified, of which 44 met the inclusion criteria and were included in either the qualitative or quantitative analysis. The methodological quality of the included studies was generally high or moderate. The quantitative analysis of the studies revealed that immunosuppression should be considered a risk factor for the development of oral cancer, with a percentage of increased risk ranging from 0.2% to 1% (95% CI: 0.2% to 1.4%). In conclusion, the results suggest that a constant and accurate follow-up should be reserved for all immunosuppressed patients as a crucial strategy to intercept lesions that have an increased potential to evolve into oral cancer.

Characterization of Active MMP9 in Chronic Inflammatory Diseases Using a Novel Anti-MMP9 Antibody

Matrix metalloproteinase 9 (MMP9), a protease implicated in multiple diseases, is secreted as an inactive zymogen and requires proteolytic removal of the pro-domain for activation. The relative levels and functionality of the pro- and active-MMP9 isoforms in tissues are not characterized. We generated a specific antibody that distinguishes an active form of MMP9, F107-MMP9, from the inactive pro-MMP9 isoform. Using multiple in vitro assays and specimen types, we show that F107-MMP9 expression is localized and disease-specific compared with its more abundant parental pro-form. It is detected around sites of active tissue remodeling, including fistulae of inflammatory bowel and dermal fissures in hidradenitis suppurativa, and is expressed by myeloid cells, including macrophages and neutrophils. Together, our findings provide insights into the distribution and potential role of MMP9 in inflammatory diseases.

Inflammatory Mediators in Oral Cancer: Pathogenic Mechanisms and Diagnostic Potential

Approximately 15% of cancers are attributable to the inflammatory process, and growing evidence supports an association between oral squamous cell carcinoma (OSCC) and chronic inflammation. Different oral inflammatory conditions, such as oral lichen planus (OLP), submucous fibrosis, and oral discoid lupus, are all predisposing for the development of OSCC. The microenvironment of these conditions contains various transcription factors and inflammatory mediators with the ability to induce proliferation, epithelial-to-mesenchymal transition (EMT), and invasion of genetically predisposed lesions, thereby promoting tumor development. In this review, we will focus on the main inflammatory molecules and transcription factors activated in OSCC, with emphasis on their translational potential.

Mediators of Inflammation - A Potential Source of Biomarkers in Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common tumour of the oral cavity, associated with significant morbidity and mortality. It is a multifactorial condition, both genetic and environmental factors being involved in its development and progression. Its pathogenesis is not fully elucidated, but a pivotal role has been attributed to inflammation, strong evidence supporting the association between chronic inflammation and carcinogenesis. Moreover, an increasing number of studies have investigated the role of different mediators of inflammation in the early detection of OSCC. In this review, we have summarized the main markers of inflammation that could be useful in diagnosis and shed some light in OSCC pathogenesis.

The associations between serum vascular endothelial growth factor, tumor necrosis factor and interleukin 4 with the markers of blood-brain barrier breakdown in patients with paraneoplastic neurological syndromes

The blood–brain barrier (BBB) disruption is a critical step in paraneoplastic neurological syndrome (PNS) development. Several cytokines have been implicated in BBB breakdown. However, the exact step-by-step mechanism in which PNS develops is unknown, and the relationship between a systemic neoplasm and BBB is multilevel. The aim of the present study was to examine serum markers of BBB breakdown (S100B protein, neuron-specific enolase, NSE) and concentrations of proinflammatory (TNF-alpha, VEGF) and anti-inflammatory/immunosuppressive cytokines (IL-4), and to establish their interrelationship in patients with PNS. We analyzed 84 patients seropositive for onconeural antibodies that originated from a cohort of 250 cases with suspected PNS. Onconeural antibodies were estimated with indirect immunofluorescence and confirmed with Western blotting. Serum S-100B was estimated using electrochemiluminescence immunoassay. NSE, VEGF, TNF-alpha and IL-4 were analyzed with ELISA. We found that S-100B protein and NSE serum concentrations were elevated in PNS patients without diagnosed malignancy, and S-100B additionally in patients with peripheral nervous system manifestation of PNS. Serum VEGF levels showed several abnormalities, including a decrease in anti-Hu positive patients and increase in PNS patients with typical manifestation and/or central nervous system involvement. Increase in TNF-alpha was observed in patients with undetermined antibodies. To conclude, the presence of paraneoplastic neurological syndrome in seropositive patients does not affect serum markers of BBB breakdown, with the exception of the group without clinically demonstrated malignancy and patients with peripheral manifestation of PNS. S-100B and NSE might increase during early phase of PNS. VEGF may be involved in typical PNS pathophysiology.

Metastasized lung cancer suppression by Morinda citrifolia (Noni) leaf compared to Erlotinib via anti-inflammatory, endogenous antioxidant responses and apoptotic gene activation

Metastasized lung and liver cancers cause over 2 million deaths annually, and are amongst the top killer cancers worldwide. Morinda citrifolia (Noni) leaves are traditionally consumed as vegetables in the tropics. The macro and micro effects of M. citrifolia (Noni) leaves on metastasized lung cancer development in vitro and in vivo were compared with the FDA-approved anti-cancer drug Erlotinib. The extract inhibited the proliferation and induced apoptosis in A549 cells (IC50 = 23.47 μg/mL) and mouse Lewis (LL2) lung carcinoma cells (IC50 = 5.50 μg/mL) in vitro, arrested cancer cell cycle at G0/G1 phases and significantly increased caspase-3/-8 without changing caspase-9 levels. The extract showed no toxicity on normal MRC5 lung cells. Non-small-cell lung cancer (NSCLC) A549-induced BALB/c mice were fed with 150 and 300 mg/kg M. citrifolia leaf extract and compared with Erlotinib (50 mg/kg body weight) for 21 days. It significantly increased the pro-apoptotic TRP53 genes, downregulated the pro-tumourigenesis genes (BIRC5, JAK2/STAT3/STAT5A) in the mice tumours, significantly increased the anti-inflammatory IL4, IL10 and NR3C1 expression in the metastasized lung and hepatic cancer tissues and enhanced the NFE2L2-dependent antioxidant responses against oxidative injuries. The extract elevated serum neutrophils and reduced the red blood cells, haemoglobin, corpuscular volume and cell haemoglobin concentration in the lung cancer-induced mammal. It suppressed inflammation and oedema, and upregulated the endogenous antioxidant responses and apoptotic genes to suppress the cancer. The 300 mg/kg extract was more effective than the 50 mg/kg Erlotinib for most of the parameters measured.

A high IL-4 production diplotype is associated with an increased risk but better prognosis of oral and pharyngeal carcinomas

OBJECTIVE

Interleukin (IL)-4 is a key cytokine in humoral and adaptive immunity. This study aimed to evaluate the association of IL-4 genetic variants (-590C>T and VNTR in intron 3) with the risk and prognosis of oral and pharyngeal squamous cell carcinoma (OPSCC).

DESIGN

A total of 1215 subjects, which included 623 healthy controls and 592 OPSCC cases (463 oral squamous cell carcinoma (OSCC) and 129 pharyngeal squamous cell carcinoma (PSCC) cases), were recruited. The genotypes were determined by TaqMan real-time assay and PCR-based assay.

RESULTS

The IL-4 genotypes at locus -590C>T and intron 3 VNTR were not correlated with increased risk of OSCC, PSCC, and OPSCC, with the exception of early-stage OPSCC (at -590C>T: T/T vs. C/C+C/T, adjusted odds ratio (AOR)=1.42, 95% CI: 1.02-1.98; at intron 3 VNTR: RP1/RP1 vs. RP2/RP2+RP2/RP1, AOR=1.46, 95% CI: 1.05-2.04). Compared with other IL-4 diplotypes, the T,RP1/T,RP1 diplotype was associated with an increased risk of OPSCC (AOR=1.37, 95% CI: 1.03-1.81), particularly early-stage OSCC (AOR=1.43, 95% CI: 1.02-2.00), PSCC (AOR=2.35, 95% CI: 1.06-5.19), and OPSCC (AOR=1.52, 95% CI: 1.10-2.11). Interactions between the IL-4 diplotype and the alcohol drinking status were found to contribute to the risk of early-stage OPSCC (p=0.024). In addition, the T,RP1/T,RP1 diplotype was correlated with better disease-specific survival (T,RP1/T,RP1 vs. other diplotypes, adjusted hazard ratio=0.70, 95% CI: 0.50-0.97).

CONCLUSION

The T, RP1/T, RP1 diplotype of IL-4 was associated with an increased risk but favourable prognosis of OPSCC.

Progesterone receptor membrane component 1 as the mediator of the inhibitory effect of progestins on cytokine-induced matrix metalloproteinase 9 activity in vitro

Progesterone (P4) and the progestin, 17α-hydroxyprogesterone caproate, are clinically used to prevent preterm births (PTBs); however, their mechanism of action remains unclear. Cytokine-induced matrix metalloproteinase 9 (MMP-9) activity plays a key role in preterm premature rupture of the membranes and PTB. We demonstrated that the primary chorion cells and the HTR8/SVneo cells (cytotrophoblast cell line) do not express the classical progesterone receptor (PGR) but instead a novel progesterone receptor, progesterone receptor membrane component 1 (PGRMC1), whose role remains unclear. Using HTR8/SVneo cells in culture, we further demonstrated that 6 hours pretreatment with medroxyprogesterone acetate (MPA) and dexamethasone (Dex) but not P4 or 17α-hydroxyprogesterone hexanoate significantly attenuated tumor necrosis factor α-induced MMP-9 activity after a 24-hour incubation period. The inhibitory effect of MPA, but not Dex, was attenuated when PGRMC1 expression was successfully reduced by PGRMC1 small interfering RNA. Our findings highlight a possible novel role of PGRMC1 in mediating the effects of MPA and in modulating cytokine-induced MMP-9 activity in cytotrophoblast cells in vitro.

Tissue inhibitor of metalloproteinases in oral squamous cell carcinomas - a therapeutic target?

Matrix metalloproteinases (MMPs) are proteases responsible for remodeling the extracellular matrix (ECM) and enabling spreading and metastasis of tumor cells, a common phenomenon in oral squamous cell carcinomas (OSCC). They are strongly blocked by several inhibitors, among which we must highlight, for their specificity and potency, the endogenous tissue inhibitors of metalloproteinases (TIMP-1, -2, -3 and -4). The goal of this paper is to describe the expression of TIMPs in OSCC, determining their relation with clinical, histological and prognostic factors, delving into OSCC regulation mechanisms and discussing the use of exogenous TIMPs to treat this type of tumors. Expression of TIMPs in OSCC is higher in tumors than in normal tissue, which correlates with an increase of metastatic risk and regional lymph node affectation. Although some metalloproteinases inhibitors (MMIs) have shown promising results in the treatment of these tumors, their use in OSCC has not been widely tested; and although some indirect MMIs, like COX-2 inhibitors, flavonoids and endostatin seem to have beneficial effects on the invasive capacity of OSCC through regulation of MMPs and TIMP levels, routine clinical use has not been accepted yet.

Propofol reduces MMPs expression by inhibiting NF-κB activity in human MDA-MB-231 cells

Propofol is a common clinical anesthesia agent which is now widely used in relieving pain of patients with chronic cancer as an adjuvant therapy. In our study, we found another effect of propofol in the therapy of chronic cancer patients. We used the breast cancer cell lines to detect the effects and molecular mechanisms of clinically relevant concentrations of propofol, finding that propofol reduced the level of MMP breast cancer by inhibition of NF-κB pathways, which restrained migration and invasion of breast cancer cells significantly. Our finding provides a new sight into propofol in cancer treatment and, suggesting that propofol not only can be an anesthesia agent which reduces pain but plays a important role of inhibiting the invasion and migration of breast cancer cells in the therapy of chronic breast cancer patients.

Shikonin inhibits tumor invasion via down-regulation of NF-κB-mediated MMP-9 expression in human ACC-M cells

OBJECTIVE

The aim of this study was to examine the anti-invasion effect of Shikonin on human high-metastatic adenoid cystic carcinoma (ACC-M) cells and to explain the possible molecular mechanism involved.

METHODS

The ACC-M cells were treated with Shikonin (0, 2.5, 5, 10 μM) for 24 h. The protein levels and gelatinolytic activities of MMP-2 and MMP-9 were analyzed using Western blot and Gelatin zymography test, respectively. Matrigel invasion assays were used to investigate tumor invasive potential and electromobility shift assays were used to determine the activity of NF-κB.

RESULTS

The invasiveness of ACC-M cells was reduced in a dose dependent manner following 24-h treatment of up to 10 μM of the Shikonin at which concentration no cytotoxicity occurred. The protein levels and gelatinolytic activities of MMP-9 were significantly suppressed by increasing Shikonin concentrations. The down-regulation of MMP-9 appeared to be via the inactivation of NF-κB as the treatment with Shikonin suppressed the protein level of phosphate-IkBa, which was accompanied by a decrease in DNA-binding level of the factor.

CONCLUSIONS

Shikonin inhibits tumor invasion via downregulation of MMP-9 expression in ACC-M cells. Pharmacologic inhibition of the NF-κB-mediated MMP-9 expression by Shikonin might be a powerful treatment option for ACC patients in future.

Immunohistochemical expression of interleukin-4, -6, -8, and -12 in inflammatory cells in surrounding invasive front of oral squamous cell carcinoma

BACKGROUND

Cytokines play important roles in the diverse interactions between tumor microenvironment and malignant cells. This study evaluated the association of interleukin (IL)-4, -6, -8, and -12 expressions and clinicopathologic parameters of 35 primary oral squamous cell carcinomas (OSCCs).

METHODS

Patients were staged according to the TNM clinical staging. Malignancy grading of invasive front was evaluated in hematoxylin-eosin (H&E)-stained slides. Immunohistochemical technique was performed on frozen tissue sections. Association between clinicopathologic parameters and IL expression were analyzed using nonparametric Kruskal-Wallis (alpha = 0.05) and Mann-Whitney U tests, with Bonferroni correction. Correlations between interleukins were analyzed by the Spearman coefficient.

RESULTS

Expression of ILs was verified in all samples; however, this finding was not related to clinicopathologic parameters. It was not the observed correlation between ILs.

CONCLUSIONS

Expression of IL-4, -6, -8, and -12 in the invasive front of OSCC is not involved with the clinicopathologic parameters of the disease.

Genetic association of cytokine DNA polymorphisms with head and neck cancer

Mutations in oncogenes or tumor suppressor genes, as well as environmental factors such as tobacco chewing or smoking, poor oral hygiene, ill-fitting dental appliances, infection by certain HPV types, or alcohol abuse, seem to be involved in the multifactorial process of carcinogenesis in head and neck. Recently, several genetic association studies have indicated that common DNA polymorphisms in low penetrance genes may affect the susceptibility of an individual to malignancy. Cytokines are an important group of proteins that regulate and mediate inflammation and angiogenesis. Tumor growth, invasion and metastasis are facilitated when there is a deregulation in their production. Cytokines include interleukins (ILs), tumor necrosis factors (TNFs) and certain growth factors (GFs). A number of genetic association studies have recently investigated the putative correlation between functional DNA polymorphisms in cytokine genes and head and neck carcinomas. This review discusses the findings of such studies in oral, nasopharyngeal and esophageal squamous cell carcinomas. Extensive research has indicated that functional polymorphisms affecting gene expression of IL-4,-6,-8,-10 as well as TNF-alpha are strongly associated with increased risk for oral cancer. Gene expression of TNF-alpha seems to be associated also with esophageal carcinomas, while for nasopharyngeal cancer the picture is yet unclear. It is generally believed that such genetic association studies will gradually increase our knowledge regarding the predisposed manifestation and advancement of these malignancies in the head and neck region.

Glucocorticoid (GC)-mediated down-regulation of urokinase plasminogen activator expression via the serum and GC regulated kinase-1/forkhead box O3a pathway

The glucocorticoid receptor (GR) and its ligand, cortisol, play a central role in human physiology. The exact mechanisms by which GR activation regulates these processes are the subject of intensive investigation. We and others have shown that GR activation can indirectly down-regulate specific genes via serum and glucocorticoid (GC) regulated kinase-1-mediated inhibition of forkhead box O3a (FOXO3a) transcriptional activity. We previously used gene expression microarrays, together with bioinformatic analyses, to identify putative FOXO3a target genes in breast epithelial cells. In this paper we refine our analysis through the use of FOXO3a chromatin immunoprecipitation (ChIP) microarrays. ChIP microarray results reveal urokinase plasminogen activator (uPA) as a putative novel target of FOXO3a in breast epithelial and breast cancer cell lines. We further show that uPA down-regulation after GC treatment requires serum and GC regulated kinase-1-mediated inactivation of FOXO3a activity. ChIP and luciferase assays confirm that FOXO3a can both occupy and transactivate the uPA promoter. Our data suggest that inactivation of FOXO3a after GR activation is an important mechanism contributing to GC-mediated repression of uPA gene expression in breast epithelial and cancer cells.

Urinary-type plasminogen activator (uPA) and its receptor (uPAR) in squamous cell carcinoma of the oral cavity

OSCC (oral squamous cell carcinoma) is the most common oral malignancy and is estimated to affect approx. 350000 new patients worldwide this year. OSCC is characterized by a high degree of morbidity and mortality, as most patients exhibit local, regional and distant metastasis at the time of diagnosis. Recent genome-wide screening efforts have identified the serine proteinase uPA (urinary-type plasminogen activator, also known as urokinase) as a strong biomarker for prediction of poor disease outcome and a key candidate for molecular classification of oral neoplasms using a 'gene signature' approach. The proteinase uPA binds a surface-anchored receptor designated uPAR (uPA receptor), focalizing proteolytic activity to the pericellular milieu. Furthermore, uPA-uPAR can interact with transmembrane proteins to modify multiple signal transduction pathways and influence a wide variety of cellular behaviours. Correlative clinical data show elevated uPA-uPAR in oral tumour tissues, with tumours exhibiting high levels of both uPA and uPAR as the most invasive. Combined in vitro, pre-clinical and clinical data support the need for further analysis of uPA-uPAR as a prognostic indicator as well as a potential therapeutic target in OSCC.

Strong association of interleukin-4 (−590 C/T) polymorphism with increased risk for oral squamous cell carcinoma in Europeans

OBJECTIVE

The present study was performed to investigate the possible association of -590 C/T polymorphism in the interleukin-4 (IL-4) gene which affects its expression with the risk for development of oral cancer.

STUDY DESIGN

Polymerase chain reaction-based restriction analysis was performed in DNA samples of 156 patients with oral squamous cell carcinoma (OSCC) and 162 healthy control subjects of equivalent gender, age, and ethnicity (Greek and German). Statistical analyses were performed conducting Fisher exact test.

RESULTS

The T/T genotype was associated with an increased risk for the development of OSCC (P = .018; OR 1.47, 95% CI 0.66-3.28), especially for early stages of this malignancy (P < .0001; OR 3.17, 95% CI 1.31-7.65).

CONCLUSIONS

The above findings are consistent with the growth-promoting role of IL-4 in head and neck cancer and its inhibitory effect on neoangiogenesis and metastasis. The present study in Europeans is not in accordance with a previous report of unclear association of this polymorphism in a Chinese population.

Severity of oral mucositis correlates with the response of oral cancer to preoperative radiochemotherapy

Oral mucositis is a dose-limiting toxic effect of radiotherapy and chemotherapy on oral cancer. The purpose of the present study is to assess the relationship between tumor response and oral mucositis in preoperative radiochemotherapy for oral cancer retrospectively. Fifty-four cases of oral squamous cell carcinoma were treated with concurrent radiochemotherapy prior to surgery. When oral mucositis was evaluated with the WHO scale, severe oral mucositis (Grades 3 and 4) developed in 22 cases (41%). A more than 50% reduction in tumor size was clinically observed in 38 cases (70%). From histopathological analysis of the surgical specimens all tumor cells observed appeared to be non-viable in 16 cases (29%). The cases with Grade 1, Grade 2, Grade 3 and Grade 4 oral mucositis included 33%, 62%, 85% and 89% of clinical good-response cases and 0%, 24%, 31% and 55% of histopathological good-response cases, respectively. This retrospective study suggests that severe oral mucositis promises a good response of oral squamous cell carcinoma to radiochemotherapy.

NF-κB involvement in tumor–stroma interaction of squamous cell carcinoma

We investigated the interaction between tumor cells and stromal fibroblasts in tumor invasion of oral squamous cell carcinoma. Gelatin zymography showed that high levels of matrix metalloproteinase (MMP)-9 were present in the tissue of squamous cell carcinoma. When tumor cells and fibroblasts were isolated from the tissue and cultured separately, significant levels of MMP-9 were lost in the culture media of tumor cells as well as fibroblasts. When tumor cells and fibroblasts were cocultured in the presence of tumor necrosis factor alpha, high levels of MMP-9 were recovered in the culture media. The levels of MMP-9, which were secreted from tumor cells, but not fibroblasts, correlated with the number of cocultured fibroblasts. Cocultured fibroblasts, moreover, enhanced the induction of an active form of MMP-9, cell motility, and the activation of a transcription factor NF-kappaB in tumor cells. Stromal fibroblasts may induce NF-kappaB activation and promote the invasion of oral squamous cell carcinoma.

Interleukin-4 suppresses IL-1-induced expression of matrix metalloproteinase-3 in human gingival fibroblasts

BACKGROUND

In periodontitis, matrix metalloproteinase-3 (MMP-3, stromelysin 1) is present at increased levels in active disease sites compared to inactive or healthy sites, and the levels are correlated with clinical parameters and associated with progression of the disease. Interleukin (IL)-4 has been shown in human skin and synovial fibroblasts and articular chondrocytes to suppress IL-1-induced expression of MMP-3, but this has not been shown in human gingival fibroblasts. The objective of this study is to determine the effects of IL-4 on the IL-1-induced expression of MMP-3 in human gingival fibroblasts isolated from patients with periodontitis.

METHODS

Northern blot analysis was performed to determine the effects of IL-4 on the IL-1 induction of MMP-3 mRNA. MMP-3 protein levels were determined by enzyme-linked immunosorbent assay (ELISA), and prostaglandin E2 (PGE2) levels were measured by enzyme immunoassay (EIA). DNA binding of activator protein (AP)-1 and nuclear factor (NF)-kappaB was assessed by electrophoretic mobility shift assay (EMSA).

RESULTS

Northern blot analysis revealed that co-incubation of gingival fibroblasts with IL-1 and IL-4 resulted in a significant decrease in MMP-3 mRNA levels compared to IL-1 alone, with a concomitant decrease in protein levels. This inhibition is dose-dependent, and is apparent as early as 3 hours after stimulation. IL-1-induced production of PGE2 was not affected in four of six cultures isolated from different individuals. Addition of exogenous PGE2 had no effect on the suppressive effects of IL-4. DNA binding of transcription factors AP-1 and NF-kappaB was not affected by IL-4.

CONCLUSIONS

IL-4 inhibits the IL-1 induction of MMP-3 in human gingival fibroblasts isolated from patients with periodontitis. This effect is independent of PGE2 and is not due to inhibition of the DNA binding activity of known transcription factors binding to the MMP-3 promoter.

Inhibition of epidermal growth factor-induced invasion by dexamethasone and AP-1 decoy in human squamous cell carcinoma cell lines

Invasive squamous cell carcinoma (SCC) cells degrade extracellular matrix (ECM) via an extracellular protease cascade that includes urokinase-type plasminogen activator (uPA), plasmin, and the metalloprotease (MMP) family of collagenases. In this study, treatment of oral SCC cells with epidermal growth factor (EGF) stimulated the cells to invade Matrigel (constructive basement membrane (BM) protein). EGF-induced cell invasion was inhibited by antibodies to uPA and by synthetic uPA inhibitors. EGF also induced increased expression of uPA and uPA receptor (uPAR) proteins and mRNA, as well as transcription factor activator protein-1 (AP-1)-DNA binding. These EGF-induced changes were inhibited by treatment with dexamethasone (DEX). DEX treatment also stimulated the production of plasminogen activator inhibitor type 1. Moreover, transfection of SCC cells with AP-1 decoy oligodeoxynucleotides (ODNs) resulted in the suppression of EGF-induced uPA and uPAR expression and Matrigel invasion. These results suggest that oral SCC cells invade Matrigel mainly through the uPA-plasmin cascade, which is mediated by the transcription factor AP-1. The uPA-uPAR interaction is essential for augmenting proteolytic activity and uPAR-mediated signaling, which ultimately induce motility and invasion. Since DEX inhibits the expression of both uPA and uPAR, it may be a useful treatment for oral SCC.