Detection of mutations by denaturing gradient gel electrophoresis.

This unit describes the procedure for determining the melting profile for a given PCR-amplified sequence by perpendicular denaturing gradient gel electrophoresis (DGGE) and, using that information, for developing a screening assay based on either parallel DGGE, CDGE (Constant Denaturant Gel Electrophoresis), or TTGE (Temporal/Temperature Gradient Electrophoresis). Four support protocols describe techniques for pouring perpendicular and parallel denaturing gradient gels, constant denaturant gels, and temporal temperature gradient gels.

Detection of mutations by single-strand conformation polymorphism (SSCP) analysis and SSCP-hybrid methods.

Single-strand conformation polymorphism (SSCP) analysis detects mutations based on the fact that single-nucleotide changes in DNA sequences alter the mobility of single-stranded DNA in nondenaturing gels. Four methods for detecting mutations based on SSCP are described here. (1) Traditional SSCP analysis is technically easy and can be used for screening large numbers of samples.

Interferon-gamma suppresses S100A4 transcription independently of apoptosis or cell cycle arrest.

The S100A4 protein has been associated with increased metastatic capacity of cancer cells, and recent studies have suggested a correlation between the expression level of S100A4 and the prognostic outcome for patients with various types of cancer. The knowledge about the mechanisms underlying the metastasis-promoting effects is still limited, and the aim of the present study was to elucidate signal transduction pathways involved in the regulation of S100A4. After treatment of human carcinoma cells with interferon-gamma (IFN-gamma), we observed downregulation of S100A4 both at mRNA and protein levels.

Effects of mRNA amplification on gene expression ratios in cDNA experiments estimated by analysis of variance.

Background: A limiting factor of cDNA microarray technology is the need for a substantial amount of RNA per labeling reaction. Thus, 20-200 micro-grams total RNA or 0.5-2 micro-grams poly (A) RNA is typically required for monitoring gene expression.

Frequent promoter hypermethylation of the O6-Methylguanine-DNA Methyltransferase (MGMT) gene in testicular cancer.

Testicular germ cell tumours are classified into two major histological subgroups, seminomas and nonseminomas. All tumours display several recurrent chromosomal aberrations, but few target genes have been identified. Previous studies have shown that genome-wide hypermethylation of CpG islands is significantly more prevalent in nonseminomas than in seminomas.