Prediction of non-reacting and reacting turbulent jets

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Expression of DNA repair proteins MSH2, MLH1 and MGMT in human benign and malignant thyroid lesions: An immunohistochemical study

Background: DNA repair is a major defense mechanism, which contributes to the maintenance of genetic sequence, and minimizes cell death, mutation rates, replication errors, DNA damage persistence and genomic instability. Alterations in the expression levels of proteins participating in DNA repair mechanisms have been associated with several aspects of cancer biology. The present study aimed to evaluate the clinical significance of DNA repair proteins MSH2, MLH1 and MGMT in benign and malignant thyroid lesions. Material/Methods: MSH2, MLH1 and MGMT protein expression was assessed immunohistochemically on paraffinembedded thyroid tissues from 90 patients with benign and malignant lesions. Results: The expression levels of MLH1 was significantly upregulated in cases with malignant compared to those with benign thyroid lesions (p=0.038). The expression levels of MGMT was significantly downregulated in malignant compared to benign thyroid lesions (p=0.001). Similar associations for both MLH1 and MGMT between cases with papillary carcinoma and hyperplastic nodules were also noted (p=0.014 and p=0.026, respectively). In the subgroup of malignant thyroid lesions, MSH2 downregulation was significantly associated with larger tumor size (p=0.031), while MLH1 upregulation was significantly associated with the presence of lymphatic and vascular invasion (p=0.006 and p=0.002, respectively). Conclusions: Alterations in the mismatch repair proteins MSH2 and MLH1 and the direct repair protein MGMT may result from tumor development and/or progression. Further studies are recommended to draw definite conclusions on the clinical significance of DNA repair proteins in thyroid neoplasia. © Med Sci Monit

Evaluation of FAK and src expression in human benign and malignant thyroid lesions

Focal Adhesion Kinase (FAK) and Src have been reported to regulate tumor growth, invasion, metastasis and angiogenesis. The present study aimed to evaluate by immunohistochemistry the clinical significance of FAK and Src expression in 108 patients with benign and malignant thyroid lesions. Total FAK expression provided a distinct discrimination between malignant and benign (p=0.00001), as well as between papillary carcinoma and hyperplastic nodules thyroid lesions (p=0.00005), being also associated with follicular cells' proliferative capacity (p=0.0003). In malignant thyroid lesions, total FAK expression was associated with tumor size (p=0.0455), and presence of capsular (p=0.0102) and lymphatic (p=0.0173) invasion. Total Src expression was borderline increased in cases of papillary carcinoma compared to hyperplastic nodules (p=0.0993), being also correlated with tumor size (p=0.0169). FAK and Src expression was ascribed to a significant extent to the phosphorylated forms of the enzymes, which provided a better discrimination between malignant and benign thyroid lesions. The current data revealed that FAK and to a lesser extent Src expression could be considered of clinical utility in thyroid neoplasia with potential use as therapeutic targets. © 2010 Arányi Lajos Foundation