The role of tissue transglutaminase (TG2) in regulating the tumour progression of the mouse colon carcinoma CT26.

The multifunctional enzyme tissue transglutaminase (TG2) is reported to both mediate and inhibit tumour progression. To elucidate these different roles of TG2, we established a series of stable-transfected mouse colon carcinoma CT26 cells expressing a catalytically active (wild type) and a transamidating-inactive TG2 (Cys277Ser) mutant. Comparison of the TG2-transfected cells with the empty vector control indicated no differences in cell proliferation, apoptosis and susceptibility to doxorubicin, which correlated with no detectable changes in the activation of the transcription factor NF-κB.

Tissue transglutaminase in tumour progression: friend or foe?

Basic biological processes in which tissue transglutaminase (TG2, tTG) is thought to be important including apoptosis, cell adhesion and migration, ECM homeostasis and angiogenesis are key stages in the multistage tumour progression cascade. Studies undertaken with primary tumours and experimental models suggest that TG2 expression and activity in the tumour body and surrounding matrix generally decreases with tumour progression, favouring matrix destabilisation, but supporting angiogenesis and tumour invasion. In contrast, in the secondary metastatic tumour TG2 is often highly expressed whereby its potential roles in cell survival both at the intra- and extracellular level become important.

Matrix changes induced by transglutaminase 2 lead to inhibition of angiogenesis and tumor growth.

Administration of active TG2 to two different in vitro angiogenesis assays resulted in the accumulation of a complex extracellular matrix (ECM) leading to the suppression of endothelial tube formation without causing cell death. Matrix accumulation was accompanied by a decreased rate of ECM turnover, with increased resistance to matrix metalloproteinase-1. Intratumor injection of TG2 into mice bearing CT26 colon carcinoma tumors demonstrated a reduction in tumor growth, and in some cases tumor regression.

A case of Opisthorchis felineus infestation in a pilot from Greece.

We describe the case of a 28-year-old man from Greece with Opistorchis felineus infestation. The patient presented with intense abdominal pain, bilious emesis and eosinophilia. He probably acquired the infection overseas, since he was a commercial airline pilot who used to fly to endemic areas and to consume raw or undercooked fish.

Blood lymphocyte subpopulations studied with monoclonal antibodies in aleukaemic stages of mycosis fungoides.

Peripheral blood lymphocytes from 21 patients with aleukaemic stages of mycosis fungoides were studied with monoclonal T cell antibodies. Patients with erythematous eruptions or infiltrated plaques (group I) had a higher percentage of OKT4+ cells than patients with a tumorous stage (group II) or normal subjects (p = 0.05).

The linkage relationships of the beta and delta hemoglobin genes.

Three new families providing information on the linkage relationships between the delta and beta hemoglobin loci are reported. One of the families contains the first reported individuals having Hb S and Hb B2 in coupling. Analysis of the information found in the literture is compatible with a recombination frequency of 3 percent between beta thalassemia and the delta structural locus.

Genetic diversity of the "Mediterranean" glucose-6-phosphate dehydrogenase deficiency phenotype.

Genetic diversity of the "Mediterranean" phenotype of G-6-PD (glucose-6-phosphate dehydrogenase) deficiency was revealed when detailed studies were performed on blood specimens from 79 Greek males with G-6-PD levels 0-10% of normal. Four different mutants were found to be responsible for the severely deficient phenotypes: two mutants. G-6-PD U-M (Union-Markham) and G-6-PD Orchomenos, were distinguishable by electrophoresis, while the other two.