Context:Significant increase in vascularity occurs during the transition from normal oral mucosa, through differing degrees of dysplasia, to invasive squamous cell carcinoma (SCC).Aims:To evaluate microvessel density (MVD) and vascular endothelial growth factor (VEGF) expression in oral tumorigenesis and correlate it with the clinicopathological characteristics.Settings and Design:VEGF expression and MVD were quantified immunohistochemically using anti-VEGF and anti-CD34 antibody.Materials and Methods:For this study we used a total of 60 archival specimens, including 10 normal oral mucosa (NOM), 7 mild epithelial dysplasia (Mild ED), 8 moderate epithelial dysplasia (Mod ED), 5 severe epithelial dysplasia (SED), 14 well-differentiated SCC, 11 moderately-differentiated SCC, and 5 poorly-differentiated SCC. VEGF expression was assessed in relation to the localization, intensity, and area of the immunohistochemically stained cells. MVD was evaluated using the Image-Pro® Plus software.Statistical Analysis:One-way ANOVA (F test) was carried out for comparing the parameters for multiple groups such as different histopathological grades of dysplasia and carcinoma. Comparison between groups was carried out using the Student's ‘t’ test. Correlations between VEGF score and MVD were estimated using the Karl Pearson coefficient of correlation.Results:VEGF and MVD appeared to increase with disease progression and were statistically higher in oral SCC than in epithelial dysplasia and normal buccal mucosa. There was significant correlation between VEGF expression and MVD.Conclusions:These findings indicate that VEGF expression is upregulated during head and neck tumorigenesis.
Oxygen derived species such as hydrogen peroxide, superoxide anion radical, hydroxyl radical (OH-), and singlet oxygen are well known to be cytotoxic and have been implicated in the etiology of a wide array of human diseases, including cancer. Various carcinogens may also partly exert their effect by generating reactive oxygen species (ROS) during their metabolism. Oxidative damage to cellular DNA can lead to mutations and may, therefore, play an important role in the initiation and progression of multistage carcinogenesis. ROS influences central cellular processes such as proliferation, apoptosis, and senescence which are implicated in the development of cancer. Understanding the role of ROS as key mediators in signaling cascades may provide various opportunities for pharmacological intervention.
Lipid peroxidation induced by reactiveoxygen species (ROS) is involved in the pathogenesis of malignancy. Overall, lipid peroxidation levels are indicated by malondialdehyde (MDA), which is the most frequently used biomarker to detect oxidative changes. Antioxidant defense systems such as glutathione (GSH) limit cell injury induced by ROS. Therefore, MDA and GSH can be used to monitor oxidative stress (OS). Hence, this study aimed to evaluate and compare both salivary and serum levels of MDA and GSH in oral leukoplakia and oral squamous cell carcinoma (OSCC) patients, and healthy controls. The study included 100 subjects comprising 30 apparently healthy controls, 30 patients with oral leukoplakia and 40 clinically and histologically diagnosed patients with OSCC. Saliva and blood samples were obtained and evaluated for MDA and GSH. The study revealed enhanced MDA levels in saliva and serum in oral leukoplakia and OSCC patients as compared to controls. On the other hand, significant decreases were seen in serum and salivary GSH levels in oral leukoplakia and OSCC patients as compared to controls. Augmentation of OS in blood and saliva is reflected by increase in MDA and decrease in GSH levels, indicating that tumor processes cause an imbalance of oxidant-antioxidant status in cell structures.(J Oral Sci 56, 135-142, 2014)
Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.
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