Xuxia Wu

Gene Expression Profiling of the Effects of Castration and Estrogen Treatment in the Rat Uterus

Abstract The development and functions of female reproductive tissues are regulated by the actions of two major sex steroid hormones, estrogen and progesterone. To investigate estrogen-dependent gene expression in the rat uterus, we studied the effect of ovariectomy with or without estrogen treatment on the uterine expression of 3000 genes using cDNA microarrays. Many genes were regulated by either treatment, but only few were reciprocally regulated by these contrasting treatments. The present study confirms previous findings and identifies several genes with expressions not previously known to be influenced by estrogen. These genes include follistatin-related protein, Thy-1 glycoprotein, α-fodrin, CD24, immediate early response 5, insulin-like growth factor-binding protein 2, growth response protein CL-6 (INSIG-1), ladinin1, class I major histocompatibility complex heavy chain, lactadherin, ezrin, and Fas-activated serine/threonine kinase. Because of their function as regulators of proliferation and apoptosis, CD24, insulin-like growth factor-binding protein 2, and Fas/Fas ligand were examined further by immunohistochemical expression and tissue localization analysis. Our analysis confirms a contrasting regulation of these gene products by ovariectomy and estrogen treatment. The present study identifies novel mediators of estrogen actions in the uterus and provides genome-wide expression data from which novel hypotheses regarding uterine function can be generated.

Apoptosis, cellular proliferation and expression of p53 in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause

Background. Cell proliferation, apoptosis and expression of p53 proteins were studied in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause.

Expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak in human uterine leiomyomas and myometrium during the menstrual cycle and after menopause

To investigate the expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak proteins in human uterine leiomyomas and homologous myometrium during the menstrual cycle and after menopause. The expression of Bcl-2, Bcl-x, Mcl-1, Bax and Bak in leiomyomas (n=24) and myometrial samples (n=22) from women with leiomyomas was measured by immunohistochemistry and Western blot. Measured by immunohistochemistry, a significant difference between leiomyomas and myometrium was observed only for the Bax protein, in tissues obtained from women in the secretory phase of the menstrual cycle. The Bcl-2 staining was more abundant in leiomyomas than in myometrium only in tissues obtained in the proliferative phase of the cycle. Bcl-2 was more abundant in leiomyomas from women of fertile age than in leiomyomas from menopausal women. No significant differences were observed for the Bcl-x or Bak proteins, whereas the Mcl-1 protein was significantly less abundant in secretory phase leiomyomas than in leiomyomas from menopausal women. Western blot analysis based on pools of tissue extracts from the different groups essentially confirmed the data obtained by immunohistochemistry. Bcl-2 family proteins are expressed in leiomyomas and myometrium in different phases related to and influenced by gonadal steroids. These proteins are suggested to interact with each other in the regulation of programmed cell death, apoptosis, but their specific role in growth control of uterine leiomyomas remains to be investigated.

Expression of basic fibroblast growth factor (bFGF), FGF receptor 1 and FGF receptor 2 in uterine leiomyomas and myometrium during the menstrual cycle, after menopause and GnRHa treatment

Background. To investigate whether basic fibroblast growth factor (bFGF) is involved in the growth regulation of human uterine leiomyomas the expression of bFGF and its receptors was measured in leiomyomas and myometrium obtained under different endocrine conditions.

mRNA-expression of often used house-keeping genes and the relation between RNA and DNA are sex steroid-dependent parameters in human myometrium and fibroids.

The content of RNA and DNA in human myometrium and fibroids obtained at different endocrine conditions varied, with the highest RNA/DNA ratio in tissues from pregnant patients, intermediate ratios in women during the menstrual cycle and the lowest in tissues from postmenopausal and GnRHa-treated patients. mRNA expression of two house-keeping genes, γ-actin and GAPDH, was highest in myometrium from pregnant women, intermediate in untreated women of fertile age and lowest in tissues from GnRHa-treated and postmenopausal women. To control for degradation of nucleic acids when measuring mRNA expression, we suggest additional analysis of gene(s), where the expression pattern is known, and that expression, whenever possible, is related to DNA, which is a more stable parameter than RNA and total nucleic acids, when there are differences in proliferation between tissues and/or groups of patients.

Expression of progesterone receptors A and B and insulin-like growth factor-I in human myometrium and fibroids after treatment with a gonadotropin-releasing hormone analogue.

OBJECTIVE To determine mRNA and protein expression of the progesterone receptor (PR) and insulin-like growth factor-I (IGF-I) in myometrium and fibroids. DESIGN Retrospective clinical study. SETTING Hospital-based and university-affiliated research laboratories. PATIENT(S) Twelve women in the proliferative phase and six women treated with GnRH analogue (GnRH-a). INTERVENTION(S) Blood sampling and collection of myometrium and fibroids. MAIN OUTCOME MEASURE(S) PR and IGF-I mRNA levels in fibroids and myometrium were analyzed by solution hybridization and in situ hybridization whereas the proteins were localized by immunohistochemistry. RESULT(S) Fibroids and myometrium from women in the proliferative phase showed significantly higher PR mRNA than the corresponding tissues from GnRH-a-treated women. The amount of cells positively stained for PR-AB and PR-B in fibroids and myometrium decreased after GnRH-a treatment compared with in the proliferative phase. The IGF-I mRNA in both fibroids and myometrium in the proliferative phase was significantly higher than those after GnRH-a treatment. The immunostaining of IGF-I showed no difference between the two tissues. There was weaker immunostaining in the GnRH-a-treated group compared with in the proliferative phase group. CONCLUSION(S) The shrinkage of fibroids after steroid deprivation is associated with alterations in PR and IGF-I expression.