Expression of TGF-b type I and II receptors in normal and cancerous human endometrium Dagmara Piestrzeniewicz-Ulanska a , Magdalena Brys a , Andrzej Semczuk b, * , Jerzy A. Jakowicki b , Wanda M. Krajewska a a Department of Cytobiochemistry, University of Lodz, Lodz, Poland b IInd Department of Gynecology, Lublin University School of Medicine, 8 Jaczewski street, 20-954 Lublin, Poland Received 5 April 2002; received in revised form 4 June 2002; accepted 6 June 2002 Abstract Transforming growth factor-b (TGF-b) belongs to a superfamily of structurally related polypeptides involved in various biological processes, including cell growth, proliferation and differentiation, angiogenesis, apoptosis, and extracellular matrix remodeling. We tried to define the different expression patterns of the TGF-b receptors by investigating the female reproductive organs during the menstrual cycle and endometrial tumorigenesis, because their role in these processes is still unclear. In this study, we examined the expression of the TGF-b type I and type II receptors in normal ðn ¼ 13Þ and carcinomatous ðn ¼ 42Þ endometrial tissue specimens using reverse transcriptase polymerase chain reaction and immunological (Western blot and enzyme linked immunosorbent assay) methods. Two uncommon female genital tract tumors, rhabdomyosarcoma of the uterine cervix and uterine carcinosarcoma, were also included. There were no significant differences between normal and cancerous endometrial tissues regarding the TGF-b receptors mRNA levels. However, we observed a markedly low TGF-b type I receptor protein level (P , 0:028; Mann–Whitney-U test), while the malignant endometrium showed a significantly higher TGF-b type II receptor protein level (P , 0:007; Mann–Whitney-U test) than the normal endometrium. Moreover, significantly elevated TGF-b receptor type II protein level was noted when depth of myometrial invasion of endometrial carcinomas was considered (P , 0:05; Mann–Whitney-U test). In contrast to uterine carcinosarcoma, in which no detectable mRNA for TGF-b type II receptor was found, we noted expression of both TGF-b receptors in rhabdomyosarcoma of the uterine cervix. However, neither rhabdomyosarcoma of the uterine cervix nor uterine carcinosarcoma displayed TGFbRI and TGFbRII protein expression. This observation corroborates the complexity of the deregulation of TGF-b receptor expression in human endometrial cancer. q 2002 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Normal endometrium; Endometrial cancer; Transforming growth factor-b; Reverse transcriptase polymerase chain reaction; Western blot; Enzyme linked immunosorbent assay 1. Introduction Transforming growth factor-b (TGF-b) belongs to the large superfamily of structurally related polypep- tides, involved in many biological processes, includ- ing cell growth, proliferation and differentiation, angiogenesis, apoptosis, and extracellular matrix remodeling [1]. TGF-b initiates signaling across the plasma membrane to the nucleus by binding to the specific, Cancer Letters 186 (2002) 231–239 0304-3835/02/$ - see front matter q 2002 Elsevier Science Ireland Ltd. All rights reserved. PII: S0304-3835(02)00351-8 www.elsevier.com/locate/canlet * Corresponding author. Tel.: 148-81-7425426; fax: 148-81- 7475710. E-mail address: tomek@asklepios.am.lublin.pl (A. Semczuk) or kalaiste@wp.pl (D. Piestrzeniewicz-Ulanska).