Differential expression of metallothionein 1 and 2 isoforms in breast cancer lines with different invasive potential: identification of a novel nonsilent metallothionein-1H mutant variant.

Metallothionein (MT), a low-molecular weight protein with pleiotropic functions, is believed to play an important role in tumorigenesis. The aim of this study was to compare the expression of functional MT-1 and MT-2 mRNA isoforms in five breast cancer cell lines ranging from noninvasive MCF7 breast cancer cells to highly aggressive MDA-MB-231 breast cancer cells together with breast myoepithelial cells in vitro by conventional semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative real-time RT-PCR. The MT-2A isoform was observed to be differentially upregulated in the invasive phenotype.

Inducible nitric oxide synthase and bcl-2 expression in nasopharyngeal cancer: correlation with outcome of patients after radiotherapy.

Purpose: The expression of inducible nitric oxide synthase (iNOS) and bcl-2 proteins was evaluated and the prognostic significance determined in nasopharyngeal cancer (NPC) patients treated by radiotherapy.

Methods And Materials: Tissue sections from 55 patients with NPC were assessed for iNOS and bcl-2 protein expression by immunohistochemistry, immunoelectron microscopy, and in situ hybridization before treatment. The markers were correlated with apoptosis (detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay) and clinicopathologic parameters.

Glutathione S-transferase pi expression in nasopharyngeal cancer.

Background: Glutathione S-transferase pi (GST-pi) is an enzyme that catalyzes the conjugation of electrophilic substrates and prevents oxidative damage. Although GST-pi expression has been analyzed in many cancers, the significance of GST-pi expression in nasopharyngeal cancer (NPC), a tumor with a high treatment failure rate, is still unclear.

Objective: To elucidate the significance of GST-pi expression in NPC.