L Tadross | PubMed Health

PubMed1997

Comparison of immunofluorometry and immunohistochemistry for the detection of p53 protein in lung cancer specimens.

Although immunohistochemical techniques are widely used to demonstrate the presence of mutant p53 protein in a wide variety of malignant tissues, quantitative enzyme-linked immunosorbent assay (ELISA)-type immunoassays offer some advantages. In this study we compared immunohistochemistry, performed on formalin-fixed, paraffin-embedded sections of 91 primary lung tumor tissues, with a highly sensitive quantitative two-site immunofluorometric assay, on extracts of fresh-frozen specimens from adjacent regions of the same tissues. Monoclonal DO-7 antibody, and the related monoclonal DO-1 with polyclonal CM-1 antibodies, were used for immunostaining and ELISA, respectively. Concentrations of p53 were expressed relative to total protein, while an immunostaining score reflected the proportion of stained malignant cells, intensity of staining, and tumor cellularity. Strong concordance was shown between the two methods by Spearman correlation (P < .001), Wilcoxon rank sum (P < .001), and contingency table (P < .001) analyses. The use of ELISA-type assays for p53 quantification in lung tumor tissues may be an alternative to the more labor-intensive histologic techniques.

Aged↗

PubMed1995

Immunoreactive prostate-specific antigen in lung tumors.

Prostate-specific antigen (PSA) is a glycoprotein produced by the epithelial cells of the prostate. PSA is currently used clinically to diagnose and monitor prostate carcinoma. In previous work we have demonstrated that 30% of breast tumors and, more rarely other tumors, contain significant amounts of PSA. PSA appears to be a favorable prognostic indicator in breast cancer. Here, using a sensitive assay, we demonstrated for the first time that lung adenocarcinomas and squamous cell carcinomas also contain PSA. PSA in lung tumor extracts was present mainly in its 33 KDa form (free PSA), at levels measurable by commercial methods. The presence of PSA was associated more closely with male patients and adenocarcinomas. The physiological role of PSA in lung tissue and the prognostic significance of PSA in lung cancer remain to be determined. These and our previous data as well as reports by other groups support the view that PSA is a ubiquitous biochemical marker of steroid hormone action.

Adenocarcinoma↗