Radioimmunoassays for the C-terminus of prothymosin alpha and the N-terminus of parathymosin alpha for the measurement of the levels of alpha-thymosins in human cancer.

A radioimmunoassay specific for the C-terminus of human prothymosin alpha was developed using the synthetic peptide [Cys-Aca degrees]-human prothymosin alpha (90-109)-OH coupled to KLH as antigen and the analogue [Tyr-Aca degrees]-human prothymosin alpha (90-109)-OH labelled with 125I as tracer. The radioimmunoassay measured intact prothymosin alpha, in the range of 2-100 pmol and does not cross-react with the partly homologous polypeptide parathymosin alpha. A major epitope was located in the segment 95-107. A radioimmunoassay specific for the N-terminus of human parathymosin alpha, also measuring intact parathymosin alpha in the range of 1-20 pmol and not cross-reacting with prothymosin alpha, was developed using the synthetic peptide [Cys-Aca degrees]-human parathymosin alpha (1-30)-OH as antigen coupled to KLH and the analogue [Tyr-Aca degrees]-human parathymosin alpha (1-10)-OH labelled with 125I as tracer. A major epitope was located in the segment 1-10. These radioimmunoassays, together with a previously established radioimmunoassay for the N-terminus of prothymosin alpha, permitted the identification of the molecular forms of the cross-reactive materials in both normal and neoplastic breast tissue extracts as intact prothymosin alpha and parathymosin alpha. It was also possible to reveal significantly higher levels of both alpha-thymosins in breast cancer tissue compared to the nearby healthy tissue--the mean of 14 samples was over 14-fold higher--suggesting a role of both prothymosin alpha and parathymosin alpha in cell proliferation. The reported radioimmunoassays are expected to facilitate the search for prognostic and/or diagnostic applications of these polypeptides in human cancer.

Metallothionein expression prevents apoptosis. II: Evaluation of the role of metallothionein expression on the chemotherapy-induced apoptosis during the treatment of acute leukemia.

Metallothioneins (MT) are low molecular weight cysteine-rich proteins, present in a wide variety of eukaryotes. Although their physiological function is not entirely understood, recently it was found that in vitro human MTs (hMTs) expression prevents apoptosis. In the present study, the apoptosis preventing effect of hMTs is evaluated in vivo, in order to correlate the apoptotic effect of chemotherapy during the treatment of acute leukemia with the expression of hMTs. The expression of hMTs was studied immunocytochemically in bone marrow smears and peripheral blood cytocentrifugations of 47 children with acute leukemia at diagnosis and during treatment. Apoptosis was quantitatively studied in peripheral blood samples during the induction therapy. Eighteen cases were found to be positive for hMTs expression at diagnosis and the mean apoptosis curve of these cases showed maximal effect on the second day of treatment, the apoptotic action of chemotherapy being completed on the tenth day. The mean apoptosis curve of the hMTs negative cases (29 cases) showed maximal effect on the first day of treatment and the apoptotic action of chemotherapy was completed on the sixth day. When considering the day on which the maximal apoptotic effect appeared and the day on which the apoptotic action of treatment was completed, the results indicated retardation of the chemotherapy-induced apoptosis dependent on hMTs expression, as a result of resistance to treatment. Furthermore, the study of hMTs expression during treatment, showed that although the apoptotic action of chemotherapy eliminates blast cells, a cell population positive for hMTs survived and increased during treatment, since they were able to escape apoptotic cell death. These findings, indicated that in vivo, hMTs constitute a cellular protective mechanism preventing chemotherapy-induced apoptosis, thus regulating the response of patients to treatment.

Chronic spondyloarthropathy mimicking abdominal disease.

Chronic spondyloarthopathy is a very common disease in the elderly. Its more common symptoms are pain in the waist, sluggishness and stiffness. Sometimes, however, it presents with the symptoms of abdominal disease. In a six year period, we observed 4,172 patients with several surgical diseases. Attentive clinical and laboratory studies of these showed that 112, who presented with abdominal symptoms, in fact, had chronic spondyloarthropathy. These cases are reported here with a brief discussion of the treatment and results.