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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.

Purpose: Functional DNA polymorphisms affecting gene expression and serum or saliva levels of interleukins IL-1 beta,-4,-6,-8,-10 and tumor necrosis factors TNF-alpha,-beta have been associated with increased risk for the development of oral squamous cell carcinoma (OSCC). The present retrospective case-control study examines possible interactions between seven cytokine genotype polymorphisms and their combinatory effect in predicting the occurrence of OSCC in Caucasians., Methods: Three hundred and thirty Greeks and Germans were studied, consisting of 162 OSCC cases and 168 healthy controls of comparable age, gender, and ethnicity. A series of multivariate logistic regression models, adjusted for age and gender, was constructed in order to assess the contribution of homozygous or heterozygous variant genotypes of polymorphisms IL-1 beta (+3953C/T), IL-4 (-590C/T), IL-6 (-174G/C), IL-8 (-251A/T), IL-10 (-1082A/G), TNF-alpha (-308G/A) and TNF-beta (+252G/A) upon overall, early and advanced stages of OSCC development., Results: The contribution of TNF-alpha and IL-6 was consistent and robust in almost all models constructed. Furthermore, when the mode of inheritance of each variant allele was taken into account in a "biological" multivariate logistic regression model, four polymorphisms emerged as primary predictors for overall stages of OSCC: TNF-alpha (OR = 15.27; 95% CI = 7.30-31.96), IL-6 (OR = 8.33; 95% CI = 3.95-17.58), IL-8 (OR = 3.54; 95% CI = 1.69-7.43) and IL-10 (OR = 2.65; 95% CI = 1.28-5.46). Finally, IL-1 beta, IL-4 and TNF-beta polymorphisms were not primary predictors of OSCC development in all constructed models., Conclusions: This study revealed the highly significant contributions of two out of seven studied cytokines (IL-6 and TNF-alpha) in the occurrence of OSCC. Based on these findings and previous reports, possible stoichiometrical interactions of cytokines leading to OSCC development are discussed.

Background: In light of the recently found contribution of angiogenic and inflammation-related factors to malignancies, this study investigated the possible association of the angiotensinogen gene (AGT) with increased risk of oral cancer., Materials and Methods: The M235T polymorphism, which influences AGT gene expression, was evaluated by restriction fragment length polymorphism analysis in the DNA samples of 163 German and Greek patients with oral squamous cell carcinoma (OSCC) and 124 healthy controls of equivalent gender, ethnicity and age., Results: No significant difference of the mutant (235T) allele, which results in higher AGT gene expression, was observed in the whole patient group in comparison with the normal controls. Similarly, compared to the controls no significant difference of either allele or carrier frequency was detected in almost every subgroup of patients. Only in the subgroup of patients with a positive family history of cancer was a significant increase of mutant T allele and carrier frequencies observed, compared to the controls (50% vs. 36.7% and 79.3% vs. 61.3%, respectively, p < 0.05 in both cases). In this particular subgroup of patients the odds ratio for OSCC of TT homozygotes was 3.57 (CI 95% 1.2-10.62), while for the MT heterozygotes it was 2.41 (CI 95% 1.06-5.49)., Conclusion: This study did not reveal an association of the AGT M235T polymorphism with oral oncogenesis, but certainly suggested a possible association of this specific polymorphism with other types of cancer. The present findings support a previous suggestion that the pathway of oral oncogenesis is probably based on angiotensin-converting enzyme and bradykinin interaction and not on AGT and angiotensin peptides.

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.

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.

The present study was performed in order to investigate the possible association of the -418 G/C polymorphism in the tissue inhibitor of metalloproteinase-2 (TIMP-2) gene, which affects its expression, with the risk of developing oral cancer. PCR-based restriction analysis was performed in DNA samples from 158 patients with oral squamous cell carcinoma (OSCC) and 168 healthy controls of equivalent sex, age and ethnicity (Greeks and Germans). Statistical analyses were performed with Fisher's exact test and the calculation of odds ratios with a 95% confidence interval (CI). The frequency of the low C allele expression was ten times greater in the patients than the controls (31% vs 2.7%, respectively; P<0.001). The C/C and G/C genotypes were associated with an increased risk of developing OSCC (P<0.001, OR=40.88, 95% CI=2.24-744.40, and P<0.001, OR=21.31, 95%=9.82-46.21, respectively). The same pattern of significant differences with the controls was also observed in the subgroups of patients in regard to the initial or advanced stages of oral cancer, family history of any type of cancer or thrombosis, and smoking habits or alcohol abuse. These findings are consistent with the reduced levels of TIMP-2 in the presence of the low expression C allele, which are insufficient to inhibit the matrix metalloproteinase-driven degradation of the extracellular matrix (leading to cancer invasion) and mitogen-driven neoangiogenesis (leading to tumor growth and metastasis). In conclusion, the studied TIMP-2 polymorphism is strongly associated with an increased risk of OSCC in Europeans carrying the low C allele expression. These results indicate that this polymorphism could serve as a genetic marker for the susceptibility of cancer in the oral cavity.