Prognostic significance of DAPK and RASSF1A promoter hypermethylation in non-small cell lung cancer (NSCLC).

The epigenetic inactivation of tumor suppressor genes may play an important role in the development and progression of many cancer types, including lung cancer. Therefore, we investigated the association between the aberrant promoter methylation of 2 genes: the Death-Associated Protein Kinase (DAPK) and the Ras Association Domain Family 1A (RASSF1A) by using methylation-specific PCR, and the clinicopathological features and prognosis in 70 radically resected non-small cell lung cancers (NSCLCs). Hypermethylation of the DAPK and RASSF1A promoters was found in 24 (34%), and in 18 (26%) tumor DNA samples, respectively. Regarding different clinicopathological features of NSCLCs, the DAPK promoter methylation was more frequently observed in squamous cell carcinoma (46%) than in adenocarcinoma (25%) and large cell carcinoma (22%), but there were no significant statistical differences (p=0.3). On the other hand, a statistically significant trend was observed between the RASSF1A methylation and a histological type of tumor (p=0.06). 45% of adenocarcinoma tumors showed RASSF1A promoter methylation in comparison to 17% of squamous cell carcinomas and 22% of large cell carcinomas. When both markers were analyzed according to the tumor-node-metastasis (TNM) staging system, no statistically significant differences were observed between stage I, II and IIIa, and the DAPK (p=0.2) and RASSF1A methylation (p=0.1). In comparison, when stage I and II were grouped together and considered vs. stage IIIa, a significant association between RASSF1A methylation and the TNM was found (p=0.03). The group of patients with tumors showing DAPK promoter methylation had significantly poorer overall survival rates (p=0.02) than the patients with tumors that did not show DAPK promoter methylation. However, the association between the RASSF1A promoter methylation status and the overall survival rates was not statistically significant (p=0.48). In conclusion, this paper supports the importance of epigenetic gene regulation in lung cancer progression and prognosis

Immunoexpression of P16INK4a, Rb and TP53 proteins in bronchiolar columnar cell dysplasia (BCCD) in lungs resected due to primary non-small cell lung cancer.

Lung cancer is the leading cause of death worldwide. High mortality comes out mainly of the fact that majority of the cases are diagnosed in advanced stadium. An expanded diagnostics of precancerous conditions would certainly contribute to lowering the mortality rate. Many of the molecular changes accompanying the multistep cancer development could be observed using the immunohistochemistry method. In this paper we describe the morphology and cell cycle proteins immunoexpression of the novel probable preinvasive lesion - bronchiolar columnar cell dysplasia (BCCD). Thirty cases of BCCD selected out of 193 patients population, treated for primary non-small cell lung cancer were investigated. Loss of P16INK4a protein was observed in 70% of all cases and was statistically significant in patients with adenocarcinoma. Two cases show abnormal cytoplasmic localization of this protein. TP53 protein accumulates in 26.7% of all BCCD. Rb protein was active in 48.3% of the BCCD cases. In two cases we observed differentiation of the cells composing BCCD into multilayer epithelium of the squamous type, which occurs with formation of desmosomes. We suppose that BCCD may be preneoplastic lesion leading to adenocarcinoma as well as to peripheral squamous cell lung cancer

Thiocyanate concentration in saliva of cystic fibrosis patients.

Thiocyanates (SCN-) are ubiquitous in nature. There are indispensable part of host defense system that act as a substrate for lactoperoxidase (LPO). In our study we present initial data on SCN- concentration in saliva of CF patients in comparison to healthy non-smokers and healthy smokers. 5 ml of saliva was collected from each subject to a sterile tube and thiocyanate concentration was measured in each sample. The results of the measurements are presented on Fig. 1. Mean concentration of SCN- in saliva of CF patients was 0.031 +/- 0.0052 g/l, in healthy non-smokers 0.039 +/- 0.0048 g/l and in healthy smokers 0.048 +/- 0.0161 g/l. The differences between each group were statistically significant. Studies on larger group of patients and probably on different material (BALF or induced sputum) should present interesting data complementing the in vitro studies

Detection of DNA methylation in eucaryotic cells.

The methods of molecular biology allow for analyzing the methylation pattern in the whole genome and in particular genes. We differentiate methylated sequences from unmethylated ones by means of cutting the genomic template with methylation-sensitive restriction enzymes or by sodium bisulfite DNA modification. Chemical modification precedes most quantitative and qualitative PCR techniques: MS-PCR, MS-nested PCR, Real-Time PCR, QAMA, HeavyMethyl, MSHRM. Restriction enzymes, on the other hand, may be used together with PCR or hybridisation methods (Southern blot and microarrays). PCRs are conducted with primers specific for methylated and unmethylated sequences and sometimes, similarly to hybridisation techniques, with specifically labeled probes or dyes intercalating to double-stranded nucleic acids. The most advanced methylation detection techniques (MALDI-TOF MS and HPLC) significantly reduce the amount of biological material used for tests, but they require specialist equipment

DNA methylation in states of cell physiology and pathology.

DNA methylation is one of epigenetic mechanisms regulating gene expression. The methylation pattern is determined during embryogenesis and passed over to differentiating cells and tissues. In a normal cell, a significant degree of methylation is characteristic for extragenic DNA (cytosine within the CG dinucleotide) while CpG islands located in gene promoters are unmethylated, except for inactive genes of the X chromosome and the genes subjected to genomic imprinting. The changes in the methylation pattern, which may appear as the organism age and in early stages of cancerogenesis, may lead to the silencing of over ninety endogenic genes. It has been found, that these disorders consist not only of the methylation of CpG islands, which are normally unmethylated, but also of the methylation of other dinucleotides, e.g. CpA. Such methylation has been observed in non-small cell lung cancer, in three regions of the exon 5 of the p53 gene (so-called "non-CpG" methylation). The knowledge of a normal methylation process and its aberrations appeared to be useful while searching for new markers enabling an early detection of cancer. With the application of the Real-Time PCR technique (using primers for methylated and unmethylated sequences) five new genes which are potential biomarkers of lung cancer have been presented

Serum soluble Fas ligand (sFasL) in patients with primary squamous cell carcinoma of the esophagus.

Esophageal carcinomas have been shown to express Fas ligand (FasL) and down-regulate Fas to escape from host immune surveillance. Circulating soluble FasL (sFasL) has been suggested to provide protection from Fas-mediated apoptosis. The aim of this study was to assess serum sFasL levels in esophageal cancer. The pretreatment levels of sFasL in the serum of 100 patients with esophageal squamous cell cancer and 41 healthy volunteers were determined by ELISA. Probability of survival was calculated according to the method of Kaplan-Meier. The prognostic influence of high and low level of sFasL was analyzed with the log-rank test. The mean serum level of sFasL in patients with esophageal cancer was significantly higher than that in healthy donors (1.567+/-1.786 vs 0.261+/-0.435,

Prognostic significance of DAPK and RASSF1A promoter hypermethylation in non-small cell lung cancer (NSCLC).

The epigenetic inactivation of tumor suppressor genes may play an important role in the development and progression of many cancer types, including lung cancer. Therefore, we investigated the association between the aberrant promoter methylation of 2 genes: the Death-Associated Protein Kinase (DAPK) and the Ras Association Domain Family 1A (RASSF1A) by using methylation-specific PCR, and the clinicopathological features and prognosis in 70 radically resected non-small cell lung cancers (NSCLCs). Hypermethylation of the DAPK and RASSF1A promoters was found in 24 (34%), and in 18 (26%) tumor DNA samples, respectively. Regarding different clinicopathological features of NSCLCs, the DAPK promoter methylation was more frequently observed in squamous cell carcinoma (46%) than in adenocarcinoma (25%) and large cell carcinoma (22%), but there were no significant statistical differences (p=0.3). On the other hand, a statistically significant trend was observed between the RASSF1A methylation and a histological type of tumor (p=0.06). 45% of adenocarcinoma tumors showed RASSF1A promoter methylation in comparison to 17% of squamous cell carcinomas and 22% of large cell carcinomas. When both markers were analyzed according to the tumor-node-metastasis (TNM) staging system, no statistically significant differences were observed between stage I, II and IIIa, and the DAPK (p=0.2) and RASSF1A methylation (p=0.1). In comparison, when stage I and II were grouped together and considered vs. stage IIIa, a significant association between RASSF1A methylation and the TNM was found (p=0.03). The group of patients with tumors showing DAPK promoter methylation had significantly poorer overall survival rates (p=0.02) than the patients with tumors that did not show DAPK promoter methylation. However, the association between the RASSF1A promoter methylation status and the overall survival rates was not statistically significant (p=0.48). In conclusion, this paper supports the importance of epigenetic gene regulation in lung cancer progression and prognosis

Detection of DNA methylation in eucaryotic cells.

The methods of molecular biology allow for analyzing the methylation pattern in the whole genome and in particular genes. We differentiate methylated sequences from unmethylated ones by means of cutting the genomic template with methylation-sensitive restriction enzymes or by sodium bisulfite DNA modification. Chemical modification precedes most quantitative and qualitative PCR techniques: MS-PCR, MS-nested PCR, Real-Time PCR, QAMA, HeavyMethyl, MSHRM. Restriction enzymes, on the other hand, may be used together with PCR or hybridisation methods (Southern blot and microarrays). PCRs are conducted with primers specific for methylated and unmethylated sequences and sometimes, similarly to hybridisation techniques, with specifically labeled probes or dyes intercalating to double-stranded nucleic acids. The most advanced methylation detection techniques (MALDI-TOF MS and HPLC) significantly reduce the amount of biological material used for tests, but they require specialist equipment