Discordant expression of mRNA and protein for urokinase and tissue plasminogen activators (u‐PA, t‐PA) in endometrial carcinoma

Abstract

Tissue samples were obtained from normal (n ϭ 92), hyperplastic (n ϭ 22) and malignant (n ϭ 35) endometria. Urokinase and tissue plasminogen activators (u-PA, t-PA) were assayed in acetate detergent buffer extracts and their mRNAs quantitated in autoradiograms of Northern blots. The tissue content of u-PA was significantly higher in adenocarcinomas compared to normal and hyperplastic endometria. Tumors with poor differentiation and extensive myometrial invasion had the highest levels. The content of t-PA was increased in hyperplastic endometria but not in adenocarcinomas. The tissue content of t-PA was inversely related to clinical stage and loss of differentiation in malignant tumors. In contrast to the protein data, u-PA mRNA was not higher and t-PA mRNA was much lower in malignant compared to benign tumors. Thus, high tumor tissue content of u-PA does not result from transcriptional regulation, and reduction of t-PA mRNA may indicate down-regulation of transcription or possibly reduced mRNA stability. Furthermore, the discrepancy between protein and mRNA for both activators probably indicates up-regulation of the translation process since decreased degradation of activator proteins is a less likely explanation.

Expression of transcription factor AP-2 in colorectal adenomas and adenocarcinomas; comparison of immunohistochemistry and in situ hybridisation

“…Evidently, high tumour tissue concentrations of these proteins did not result from transcriptional regulation, although the reduction of mRNA could indicate downregulation of transcription or possibly reduced mRNA stability. 36 In conclusion, our results revealed reduced AP-2 protein expression in colorectal carcinomas, and that reduced cytoplasmic AP-2 and AP-2 protein expression correlated inversely with colorectal carcinoma malignancy. Adenomas were more often AP-2 positive than carcinomas.…”

Differential localization and expression of urokinase plasminogen activator (uPA), its receptor (uPAR), and its inhibitor (PAI-1) mRNA and protein in endometrial tissue during the menstrual cycle

“…Both our present finding of reduced uPA mRNA in the early and middle secretory phase, and our previous finding of increased internalization and degradation of uPA in stromal cells exposed to progesterone, suggest reduction of uPA protein in the secretory phase. This has, however, not been confirmed by quantification of uPA protein in endometrial tissue extracts reported by others and ourselves (Koh et al, 1992;Nordengren et al, 1998). However, the cyclic pattern of uPA mRNA expression is much better reflected by Figure 5.…”

“…In contrast, tissue homogenates will include glandular secretion, and an ELISA will detect its content of uPA. Thus, the endometrial tissue content of uPA protein was not different between the proliferative and secretory phases (Koh et al, 1992;Nordengren et al, 1998).…”

B7-H3 and B7-H4 expression in phyllodes tumors of the breast detected by RNA in situ hybridization and immunohistochemistry: Association with clinicopathological features and T-cell infiltration

“…Possible explanations include increased translation of available mRNA and decreased elimination of activator proteins in tissues. 27 In this study, stromal B7-H3 mRNA and protein expression differed among the three grades of PTs and significantly increased with the progression of PTs from benign to malignant. Stromal B7-H3 mRNA and protein expression significantly differed between borderline or malignant PTs and benign PTs but not between borderline PTs and malignant PTs.…”