Human Defensins: Potential Tools for Clinical Applications

As components of the innate immune system, antimicrobial peptides in the form of human defensins play an important role in host defense by serving as the epithelial layer’s biochemical barrier against local infections. Recent studies have shown these molecules to have far more additional cellular functions besides their antimicrobial activity. Defensins play a role in cell division, attraction and maturation of immune cells, differentiation and reorganization of epithelial tissues, wound healing and tumor suppression. This multitude of function makes human defensins appear to be excellent tools for therapeutic approaches. These antimicrobial peptides may be used directly as a remedy against bacterial and viral infections. Furthermore, the application of human defensins can be used to promote wound healing and epithelial reorganization. In particular, human β-defensins have a strong impact on osteoblast proliferation and differentiation. Human β-defensins have already been applied as a vaccination against HIV-1. Another potentially useful characteristic of defensins is their suitability as diagnostic markers in cancer therapy. In particular, α-defensins have already been used for this purpose. Human α-defensin-3, for example, has been described as a tumor marker for lymphocytes. High gene expression levels of α-defensin-3 and -4 have been detected in benign oral neoplasia, α-defensin-6 is considered to be a tumor marker for colon cancer

Occurrence of Human Defensins and S100 Proteins in Head and Neck Basal Cell Carcinoma (BCC) Entities: hBD3 and S100A4 as Potential Biomarkers to Evaluate Successful Surgical Therapy

Background: The goal of this study is the identification of potential marker molecules for characterizing different basal cell carcinoma entities, to help improve clinical decisions for surgical resection therapy. Methods: Three different entities, sclerodermiform, solid and superficial basal cell carcinomas, were subjected to immunohistochemical microscopy and histomorphometric analyses for human α- (DEFA1/3; DEFA4) and β-defensins (hBD1/2/3) and special S100 proteins (S100A4/7/8/9). Thirty specimens of the three entities were evaluated. Analyses were performed by comparing tissue and cellular localization and staining intensities of tumorous with non-tumorous areas. Staining intensities were semiquantitatively examined by using an RGB-based model. Results: Human defensins are present in all three entities of basal cell carcinomas. They all show cytoplasmic immunostaining in cells of the epithelium, stroma and tumor. Notably, human β-defensin3 is accumulated in the cell nuclei of sclerodermiform and superficial basal cell carcinomas. S100A4 and A7 are undetectable in tumor regions. However, S100A4 occurs in cancer-associated stroma cells with nuclear staining in superficial basal cell carcinomas. Conclusion: Two candidates, namely hBD3 and S100A4, might be used as potential clinical tools for evaluating successful surgical resection therapy to avoid aesthetic and functional facial deformation

Human α-defensin (DEFA) gene expression helps to characterise benign and malignant salivary gland tumours

<p>Abstract</p> <p>Background</p> <p>Because of the infrequence of salivary gland tumours and their complex histopathological diagnosis it is still difficult to exactly predict their clinical course by means of recurrence, malignant progression and metastasis. In order to define new proliferation associated genes, purpose of this study was to investigate the expression of human α-defensins (DEFA) 1/3 and 4 in different tumour entities of the salivary glands with respect to malignancy.</p> <p>Methods</p> <p>Tissue of salivary glands (n=10), pleomorphic adenomas (n=10), cystadenolymphomas (n=10), adenocarcinomas (n=10), adenoidcystic carcinomas (n=10), and mucoepidermoid carcinomas (n=10) was obtained during routine surgical procedures. RNA was extracted according to standard protocols. Transcript levels of DEFA 1/3 and 4 were analyzed by quantitative realtime PCR and compared with healthy salivary gland tissue. Additionally, the proteins encoded by DEFA 1/3 and DEFA 4 were visualized in paraffin-embedded tissue sections by immunohistochemical staining.</p> <p>Results</p> <p>Human α-defensins are traceable in healthy as well as in pathological altered salivary gland tissue. In comparison with healthy tissue, the gene expression of DEFA 1/3 and 4 was significantly (p<0.05) increased in all tumours – except for a significant decrease of DEFA 4 gene expression in pleomorphic adenomas and a similar transcript level for DEFA 1/3 compared to healthy salivary glands.</p> <p>Conclusions</p> <p>A decreased gene expression of DEFA 1/3 and 4 might protect pleomorphic adenomas from malignant transformation into adenocarcinomas. A similar expression pattern of DEFA-1/3 and -4 in cystadenolymphomas and inflamed salivary glands underlines a potential importance of immunological reactions during the formation of Warthin’s tumour.</p

Family-based association study of the MTHFR polymorphism C677T in patients with nonsyndromic cleft lip and palate from central Europe.

Item does not contain fulltextOBJECTIVE: The 677C-->T allele in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene has been implicated in the etiology of nonsyndromic cleft lip and palate (CL/P). This study involved a family-based association study of the MTHFR polymorphism. PATIENTS/PARTICIPANTS: We examined 181 patients with CL/P of central European descent and their parents for this variant. RESULTS: The transmission disequilibrium test (TDT) did not confirm an association between the MTHFR 677C-->T polymorphism and nonsyndromic CL/P as previously suggested (p = .36). When comparing the offspring of mothers with periconceptional use of folate to those without, no statistically significant differences were found (p = .708). CONCLUSION: Our data suggest that the MTHFR 677C-->T polymorphism does not make a major contribution to the occurrence of CL/P among central Europeans

Meta-analysis and pooled analysis of GSTM1 and CYP1A1 polymorphisms and oral and pharyngeal cancer: a HuGE-GSEC review

The association of GSTM1 and CYP1A1 polymorphisms and oral and pharyngeal cancers was assessed through a meta-analysis of published case-control studies and a pooled analysis of both published and unpublished case-control studies from the Genetic Susceptibility to Environmental Carcinogens database (http://www.upci.upmc.edu/research/ccps/ccontrol/index.html ). Thirty publications used in the meta-analysis included a total of 7783 subjects (3177 cases and 4606 controls); 21 datasets, 9397 subjects (3130 cases and 6267 controls) were included in the pooled analysis. The GSTM1 deletion was 2-fold more likely to occur in African American and African cases than controls (odds ratio: 1.7, 95% confidence interval: 0.9-3.3), although this was not observed among whites (odds ratio: 1.0, 95% confidence interval: 0.9-1.1). The meta-analysis and pooled analysis showed a significant association between oral and pharyngeal cancer and the CYP1A1 MspI homozygous variant (meta-ORm2/m2: 1.9, 95% confidence interval: 1.4-2.7; Pooled ORm2m2: 2.0, 95% confidence interval: 1.3-3.1; ORm1m2 or [infi]m2m2: 1.3, 95% confidence interval: 1.1-1.6). The association was present for the CYP1A1 (exon 7) polymorphism (ORVal/Val: 2.2, 95% confidence interval: 1.1-4.5) in ever smokers. A joint effect was observed for GSTM1 homozygous deletion and the CYP1A1 m1m2 variant on cancer risk. Our findings suggest that tobacco use and genetic factors play a significant role in oral and pharyngeal cancer