RESUMO
Genetic association studies have implicated functional DNA polymorphisms in genes encoding factors related to angiogenesis, inflammation and thrombosis with increased risk for oral squamous cell carcinoma (OSCC). This study examines possible interactions between nine such genotype polymorphisms and their combinatory effect in assessing the OSCC risk in a European population. OSCC cases (N=162) and healthy controls (N=168) of comparable age, gender, and ethnicity (Greeks and Germans) were studied. Multivariate logistic regression models were constructed in order to assess the contribution of homozygous or heterozygous variant genotypes of polymorphisms MMP-1 (-1607 1G/2G), MMP-3 (-1171 5A/6A), MMP-9 (-1562C/T), TIMP-2 (-418C/G), VEGF (+936C/T), GPI-alpha (+807C/T), PAI-1 (4G/5G), ACE (intron 16D/I) and TAFI (+325C/T) upon overall, early and advanced stages of OSCC. Four out of nine polymorphisms affecting PAI-1, MMP-9, TIMP-2 and ACE expression contributed significantly in OSCC prediction in the various logistic regression models. Based on these findings and previous reports, possible interactions of the implicated factors leading to OSCC development, as well as an algorithm of risk estimation are discussed.
Assuntos
Carcinoma de Células Escamosas/genética , Inflamação/genética , Neoplasias Bucais/genética , Trombose/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/irrigação sanguínea , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Alemanha/etnologia , Grécia/etnologia , Humanos , Masculino , Metaloproteinases da Matriz/sangue , Metaloproteinases da Matriz/genética , Pessoa de Meia-Idade , Modelos Genéticos , Neoplasias Bucais/irrigação sanguínea , Peptidil Dipeptidase A/sangue , Peptidil Dipeptidase A/genética , Inativadores de Plasminogênio/sangue , Inativadores de Plasminogênio/genética , Polimorfismo Genético , Estudos Retrospectivos , Medição de Risco , Inibidores Teciduais de Metaloproteinases/sangue , Inibidores Teciduais de Metaloproteinases/genéticaRESUMO
Oral squamous cell carcinoma (OSCC) is a common cancer characterised by low survival rate and poor prognosis. The multistep process of oral carcinogenesis is affected by multiple genetic events such as alterations of oncogenes and tumour suppressor genes. The use of appropriate experimental animal models that accurately represent the cellular and molecular changes which are associated with the initiation and progression of human oral cancer is of crucial importance. The Syrian golden hamster cheek pouch oral carcinogenesis model is the best known animal system that closely correlates events involved in the development of premalignant and malignant human oral cancers. Therefore, we established an experimental system of chemically induced oral carcinogenesis in hamsters, in order to study different stages of tumour formation: normal mucosa, hyperkeratosis, hyperplasia, dysplasia, early invasion, well differentiated OSCC and moderately differentiated OSCC. We investigated the expression of oncogenes EGFR, erbB2, erbB3, FGFR-2, FGFR-3, c-myc, N-ras, ets-1, H-ras, c-fos and c-jun, apoptosis markers Bax and Bcl-2, tumour suppressor genes p53 and p16, and cell proliferation marker Ki-67 in the sequential stages of hamster oral oncogenesis. Here, we describe the findings of the experimental model in regard to the involvement of signal transduction pathways in every stage of cancer development. Increased apoptosis and cell proliferation were observed in early stages of oral oncogenesis. Furthermore, the increased expression of transmembrane receptors (EGFR, erbB2, FGFR-2 and FGFR-3) as well as the increased expression of nuclear transcriptional factors in early stages of oral cancer indicates that these molecules may be used as early prognostic factors for the progression of OSCC. Since the expression of both H-ras and N-ras do not seem to affect signal transduction during oral oncogenesis, it can be assumed that a different signalling pathway, such as the PI3K and/or PLCgamma pathway, may be implicated in the pathogenesis of OSCC.
Assuntos
Carcinoma de Células Escamosas/patologia , Modelos Animais de Doenças , Neoplasias Bucais/patologia , Animais , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Cricetinae , Progressão da Doença , Mesocricetus , Neoplasias Bucais/metabolismo , Proteínas de Neoplasias/metabolismo , Lesões Pré-Cancerosas/metabolismo , Lesões Pré-Cancerosas/patologia , Transdução de SinaisRESUMO
Markers of cell proliferation (Ki-67 antigen) and apoptosis (Bax, Bcl-2) were studied in an experimental model of chemically induced carcinogenesis in normal and diabetic (type I) Sprague-Dawley rats. Thirteen diabetic and 12 normal rats developed cancer after 4-nitroquinoline-N-oxide treatment, while 6 diabetic and 6 normal animals were used as controls. The biopsies were classified pathologically (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma) and studied immunohistochemically using monoclonal antibodies against Bax, Bcl-2 and Ki-67 proteins. The Bcl-2/Bax ratio was almost stable during the oncogenesis process in the diabetic rats, whereas the normal rats showed an increased Bcl-2/Bax ratio during the stage of moderately differentiated carcinoma. In contrast, Ki-67 expression was higher in diabetic rats than in normal ones in almost all stages of oral oncogenesis, and it reached significantly increased levels in the stages of normal control tissue, dysplasia and moderately differentiated squamous cell carcinoma. These data suggest that diabetes results in increased cell proliferation during oral oncogenesis, but this is accomplished without affecting the Bax/Bcl-2-mediated apoptotic pathways.
Assuntos
Carcinoma de Células Escamosas/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Neoplasias Bucais/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteína X Associada a bcl-2/análise , Animais , Apoptose/fisiologia , Carcinoma de Células Escamosas/induzido quimicamente , Proliferação de Células , Feminino , Antígeno Ki-67/análise , Neoplasias Bucais/induzido quimicamente , Distribuição Aleatória , Ratos , Ratos Sprague-DawleyRESUMO
AIM: In light to recently found contribution of factors associated with angiogenesis, thrombosis and inflammation to carcinogenesis, we investigated the possible association of metalloproteinase-9 (MMP-9) with increased risk of oral cancer. METHODS: In DNA samples of 152 patients with oral squamous cell carcinoma and 162 healthy controls of comparable ethnicity, age and sex, we studied the -1562 C/T polymorphism in the MMP-9 gene promoter, which affects its transcription. RESULTS: The detected frequency for the high expression T allele in the patients' group was significantly increased in comparison to that of the control group (22% versus 15%, respectively; P<0.05). This difference was due to the relative increase of C/T heterozygotes in the group of patients, in comparison to controls (P<0.05, 95% OR 1.92, CI 1.21-3.06). The same pattern of significance was observed between controls and the subgroups of patients with initial (I & II) stages of cancer, without positive family history of cancer or thrombophilia, with smoking and alcohol abuse habits. CONCLUSIONS: The investigated MMP-9 polymorphism has a strong association with increased risk for developing oral cancer in a subset of the general population. These results are in accordance to previous studies of constitutive expression and secretion of MMP-9 in invasive oral carcinoma cell lines. The observation that T allele carriers have an increased risk for developing oral cancer only in initial stages, but not in advanced ones, may be due to the role of MMP-9 in the inhibition of angiogenesis by generating angiostatin from plasminogen.
Assuntos
Carcinoma de Células Escamosas/genética , Metaloproteinase 9 da Matriz/genética , Neoplasias Bucais/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Consumo de Bebidas Alcoólicas , Carcinoma de Células Escamosas/metabolismo , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Metaloproteinase 9 da Matriz/biossíntese , Pessoa de Meia-Idade , Neoplasias Bucais/metabolismo , Polimorfismo Genético , Regiões Promotoras Genéticas , Fatores de Risco , FumarRESUMO
ErbB2 and erbB3 transmembrane receptors, known to be associated with neuronal and skeletal muscle developmental function, seem to play an important role in human oral oncogenesis. This study was designed to determine gradual erbB2 and erbB3 expression in an experimental animal system of induced oral carcinogenesis in Syrian golden hamsters. Thirty-seven animals were divided into one control group (N=7) and three experimental groups (N=10 each one), which were treated with carcinogen 9,10-dimethyl-1,2-benzanthracene and sacrificed at 10, 14 and 19 weeks after treatment. The histological status of observed lesions in the three experimental groups corresponded well with tumour advancement (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma). Tissue sections ranging from normal mucosa to squamous cell carcinoma were studied using monoclonal antibodies against erbB2 and erbB3 proteins. Cytoplasmic erbB2 expression was gradually increased in pre-cancerous stages, remained stable in initial tumour stages and substantially decreased in moderately-differentiated carcinomas, suggesting that it may be useful as an early prognostic factor. On the contrary, erbB3 was not expressed at all either in normal or tumour tissue.
Assuntos
Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Neoplasias Bucais/metabolismo , Músculo Esquelético/metabolismo , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Animais , Biomarcadores Tumorais/análise , Carcinógenos/farmacologia , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/fisiopatologia , Cricetinae , Imuno-Histoquímica , Masculino , Mesocricetus , Neoplasias Bucais/genética , Neoplasias Bucais/fisiopatologia , Valor Preditivo dos Testes , Receptor ErbB-2/análise , Receptor ErbB-3/análise , Regulação para Cima/fisiologiaRESUMO
PURPOSE: Based on the well-established role of vascular endothelial growth factor (VEGF) in tumor-associated angiogenesis in several cancer types and its undefined role in oral oncogenesis, we investigated the possible association of an expression-regulating polymorphism (+936C/T) with risk for oral squamous cell carcinoma (OSCC). METHODS: We studied the allele frequencies of the +936C/T polymorphism in DNA samples of 144 patients with OSCC and 153 healthy controls matched by age, gender and ethnicity, using restriction fragment length polymorphism typing analysis. RESULTS: The low-expression T allele was significantly increased in the total patient group compared to controls (P = 0.008), due to a significant over-representation of C/T heterozygotes compared to C/C homozygotes (P = 0.007). The same pattern was observed in most patient subgroups and more noticeably in patients with a positive family history of cancer (P = 0.001). Interestingly, the increase in T allele frequency was only significant in patients at cancer stages I and II (P = 0.006). CONCLUSIONS: This study clearly indicates that the low-VEGF-production T allele is strongly associated with increased risk for OSCC. In addition, the impressive T allele frequency increment in patients with a positive family cancer history suggests that this allele may also be involved in other malignancies. The fact that this significant increase was observed only in patients with early cancer stages may imply that low VEGF levels might hinder subsequent tumorigenesis. Our findings might be the result of either unidentified properties of the +936 C/T polymorphism or of a strong linkage disequilibrium between this polymorphism and another genetic locus.
Assuntos
Carcinoma de Células Escamosas/genética , Predisposição Genética para Doença , Neoplasias Bucais/genética , Polimorfismo de Fragmento de Restrição , Fator A de Crescimento do Endotélio Vascular/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da PolimeraseRESUMO
AIMS: In light of recently found contribution of angiogenic and inflammation-related factors to malignancies, this study investigated the possible association of interleukin-8 gene (IL-8) to increased risk of oral cancer. METHODS: The IL-8 (-251 A/T) polymorphism, which influences IL-8 gene expression, was evaluated by restriction fragment length polymorphism analysis in DNA samples of 158 German and Greek patients with oral squamous cell carcinoma and 156 healthy controls of equivalent sex, ethnicity and age. RESULTS: Significant increase of mutant (A-251) allele, which results in higher IL-8 gene expression, was observed in all patients in comparison to normal controls (P<0.001). The A/T heterozygotes had a two-fold greater risk (odds ratio 1.76, CI 1.11-2.79) for developing oral cancer compared to normal TT homozygotes. Furthermore, significantly increased values of mutant allele frequencies compared to controls were observed in all patients as well as in subgroups of patients with or without positive history of cancer (P<0.05 and P<0.001, respectively) and with or without positive history of thrombophilia (P<0.05 and P<0.001, respectively). CONCLUSIONS: In light to known observations of elevated plasma levels of IL-8 in several types of cancer including oral squamous cell carcinoma, the findings of this study suggest that the mutant allele of the (-251 A/T) polymorphism may be a major contributing genetic factor to risk for oral cancer.
Assuntos
Carcinoma de Células Escamosas/genética , Interleucina-8/genética , Neoplasias Bucais/genética , Polimorfismo Genético , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Alemanha , Grécia , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , RiscoRESUMO
In view of the recently found contribution of factors associated with thrombosis and inflammation to carcinogenesis, we investigated the possible association of interleukin-6 (IL-6) with an increased risk of oral cancer. In DNA samples of 162 patients with oral squamous cell carcinoma and 156 healthy controls of comparable ethnicity, age and sex, we studied the -174 G>C polymorphism in the IL-6 gene, which affects its transcription. C allele frequencies were significantly increased in patients compared to controls, 42.6% versus 23.1% (p<0.001). The CC homozygotes had a 7-fold greater risk of developing oral cancer (odds ratio 7.39, 95% CI 2.61-20.92), while the GC heterozygotes had a 4-fold greater risk (odds ratio 3.74, 95% CI 2.29-6.11). A significant increase in C alleles was observed in patients regardless of their smoking or alcohol consumption habits, early or advanced stage of cancer, and presence or absence of a family history for cancer or thrombophilia (p<0.001; Fisher's exact test). These findings suggest that the -174 G>C polymorphism, by affecting IL-6 gene expression, is strongly associated with oral oncogenesis.
Assuntos
Interleucina-6/genética , Neoplasias Bucais/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/etiologiaRESUMO
In light of the recently observed contribution of thrombosis-related factors to carcinogenesis, we investigated the possible association of plasminogen activator inhibitor-1 (PAI-1) with increased risk for oral cancer. In DNA samples of 104 patients with oral squamous cell carcinoma and 106 healthy controls of comparable ethnicity, age and sex, we studied the 4G/5G polymorphism in the PAI-1 gene, which affects its expression. The mutant 4G allele and carrier frequencies were significantly increased in patients compared to controls (65.9% versus 49.5%; 88.5% versus 69.8% respectively, P<0.01). That increase was even higher in patients with a positive family history for thrombophilia or without one for cancer (P<0.001). Interestingly, significant difference from controls was observed only in patients with cancer stages I and II. These findings suggest that the 4G allele, by resulting in higher PAI-1 expression, is a major contributing factor in early stages of oral oncogenesis. Possibly, increased PAI-1 promotes initial development of oral cancer through regulation of cell detachment and delays further tumor progression by inhibiting vascularization.
Assuntos
Carcinoma de Células Escamosas/genética , Neoplasias Bucais/genética , Inibidor 1 de Ativador de Plasminogênio/genética , Polimorfismo Genético , Regiões Promotoras Genéticas , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/patologia , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/patologia , Estadiamento de Neoplasias , Fatores de RiscoRESUMO
AIMS: In light to association of increased platelet glycoprotein Ia (GPIa) expression with tumor invasion and metastasis in several types of cancer, we investigated the possible contribution of a common polymorphism (C807/T807), affecting the GPIa gene expression, in the development of oral cancer. METHODS: DNA samples of 110 patients with oral cancer and 114 healthy controls were examined by allele-specific polymerase chain reaction followed by electrophoretic analysis. RESULTS: The mutant T807 allele homozygotes were significantly increased in the group of patients compared to the control group (P < 0.001). Furthermore, significantly increased frequency of mutant alleles compared to controls was observed in the subgroup of patients with a positive history for cancer (P < 0.01). CONCLUSIONS: The obtained results indicate that the C807/T807 polymorphism is indeed a genetic predisposing factor which contributes to increased risk for oral cancer.
Assuntos
DNA de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica , Integrina alfa2/genética , Neoplasias Bucais/sangue , Polimorfismo Genético , Alelos , Predisposição Genética para Doença , Genótipo , Humanos , Técnicas In Vitro , Integrina alfa2/metabolismo , Neoplasias Bucais/genética , Neoplasias Bucais/patologia , Mutação , Reação em Cadeia da Polimerase , Estudos RetrospectivosRESUMO
Markers of cell proliferation (Ki-67 antigen) and apoptosis (Bax, Bcl-2) were studied in an experimental system of induced oral carcinogenesis in Syrian golden hamsters. Thirty-seven animals were divided into one control group and three experimental groups, which were treated with a carcinogen and sacrificed at 10, 14 and 19 weeks after treatment. The histological status of the lesions in the three experimental groups corresponded well with tumour advancement (from oral mucosal dysplasia to moderately differentiated squamous cell carcinoma). Tumour sections were studied using monoclonal antibodies against Bax, Bcl-2 and Ki-67 proteins. Pro-apoptotic Bax expression maintained high levels during all stages of oral carcinogenesis. Anti-apoptotic Bcl-2 expression decreased significantly in dysplastic and early invasion lesions and consequently increased almost to normal tissue level in consequent stages. Finally, Ki-67 expression increased sharply in initial stages of oral carcinogenesis, but significantly decreased in later stages.
Assuntos
Carcinoma de Células Escamosas/patologia , Transformação Celular Neoplásica/patologia , Neoplasias Bucais/patologia , Lesões Pré-Cancerosas/patologia , Animais , Apoptose , Carcinoma de Células Escamosas/induzido quimicamente , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células , Transformação Celular Neoplásica/metabolismo , Cricetinae , Progressão da Doença , Antígeno Ki-67/metabolismo , Masculino , Mesocricetus , Neoplasias Bucais/induzido quimicamente , Neoplasias Bucais/metabolismo , Proteínas de Neoplasias/metabolismo , Lesões Pré-Cancerosas/induzido quimicamente , Lesões Pré-Cancerosas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/metabolismoRESUMO
PURPOSE: We investigated whether the mutant methylenetetrahydrofolate reductase (MTHFR) increases risk for oral cancer. The common germ-line mutation C677T in the MTHFR gene significantly diminishes specific activity of the enzyme, which is responsible for the circulating form of folate. Folate deficiency is associated with increased risk for thrombosis, as well as for several types of cancer, through disruption of DNA methylation, DNA synthesis and deficient DNA repair. METHODS: We searched for the C677T mutation by restriction fragment analysis of PCR products in DNA samples of 110 patients with oral squamous cell carcinoma and 120 healthy controls of comparable ethnicity, age and sex. RESULTS: The number of heterozygotes was significantly different in the two groups (P<0.005), as well as in subgroups of patients with or without a positive family history for cancer, compared to normal controls (P<0.01 and P<0.005, respectively). Furthermore, the subgroup of patients with a positive family history for thrombophilia had a significant increase both in the frequencies of mutant alleles (P<0.01) and heterozygotes (P<0.001) in comparison to normal controls. CONCLUSIONS: The obtained results suggest that the MTHFR mutation is a minor contributing factor in oncogenesis in the oral region, in conjunction with low dietary uptake of folate.