Estrogen-Induced Stromal FGF18 Promotes Proliferation and Invasion of Endometrial Carcinoma Cells Through ERK and Akt Signaling.

OBJECTIVE: The aim of this study was to evaluate whether estrogen promoted the proliferation and invasion of endometrial carcinoma (EC) cells through paracrine FGFs in endometrial stromal cells (ESCs). PATIENTS AND METHODS: We screened gene alterations in a primary ESC culture after 10 nM estrogen treatment using an Agilent mRNA microarray. We knocked down stromal FGF18 expression in a co-culture system and aimed to explore the contribution of E2-induced stromal FGF18 to the proliferation and invasion of EC cells. To determine the effective receptors and detailed downstream signaling of FGF18, we co-cultured estrogen-treated hESCs with FGFR1-, FGFR2-, FGFR3- or FGFR4-knockdown Ishikawa cells. Finally, we detected FGF18 expression in clinical samples, including several primary cultures of different ESCs and a series of tissue microarrays (TMAs) of 90 patients with EC. RESULTS: A few genes altered significantly in estrogen-treated primary ESCs, but only FGF18 was noticeably enhanced among the FGF family genes. Knockdown of FGF18 expression in hESCs inhibited the promoting effect of FGF18 on the proliferation and invasion of EC cells. FGF18 bound FGFR2 and FGFR3 in Ishikawa cells to activate downstream ERK and Akt pathways and to promote the viability of EC cells. The FGF18-FGFR2 and FGF18-FGFR3 pathways had close correlations with Survivin and CD44V6 expression but not with P53. Primary ESCs of endometrioid EC (EEC, type I EC) had higher FGF18 expression than ESCs of normal endometrium (NE), endometrial atypical hyperplasia (EAH) and type II EC. CONCLUSION: Estrogen induced FGF18 in ESCs to promote the proliferation and invasion of EC cells, and FGFR inhibitors should be considered as promising candidate targets for EC treatment.

Oestrogen receptor α mediates 17ß-estradiol enhancement of ovarian cancer cell motility through up-regulation of survivin expression.

OBJECTIVE: To determine the role of oestrogen receptor α (ERα) in the regulation of survivin expression by 17ß-estradiol (E(2)) in ovarian cancer cells and to evaluate the mechanism of E(2) action on ovarian cancer cell migration. METHODS: We performed RT-PCR and Western blot analysis to assess the expression of ERα in the ovarian cancer cell lines NIH:OVCAR-3 and SKOV-3. Full-length ERα cDNA was reintroduced into SKOV-3 cells through stable transfection. After treatment with E(2), with or without pre-incubation of anti-oestrogen compound ICI 182780, RT-PCR and Western blot analysis were performed to detect survivin expression at the mRNA and protein levels. RNA interference (RNAi) was used to inhibit the expression of survivin in SKOV-3 cells. Wound healing-induced migration and Matrigel invasion experiments were performed to determine the motility of ovarian cancer cells. RT-PCR and gelatin zymography were used to detect the expression and activity of MMP-9 in SKOV-3 cells. RESULTS: A stably transfected clone with over-expression of ERα, SKOV-α, was isolated. Exogenous or endogenous expression of ERα in SKOV-3 or NIH:OVCAR-3 cells resulted in a significant up-regulation of survivin in the presence of E(2). Pre-treatment with ICI 182780 attenuated the up-regulation of survivin by E(2). Previous data from our laboratory showed that E(2) enhanced the motility of ovarian cancer cells. RNAi strongly inhibited survivin expression in SKOV-3 cells. Knock-down of survivin expression reduced the migration and invasion of SKOV-3 cells, which correlated with down-regulation of MMP9 mRNA expression and activity. CONCLUSIONS: ERα may be responsible for the up-regulation of survivin after E(2) treatment in ovarian cancer cells. The mechanism of oestrogen-promoted ovarian cancer metastasis may due to the up-regulation of survivin conducted through the ERα signalling pathway.

[Expression of glyoxalase I and its effect on cell proliferation and apoptosis in endometrial carcinoma].

OBJECTIVE: To examine the expressions of glyoxalase I (GLO-I) in endometrial cancer tissues and cell lines and to investigate the roles of GLO-I on proliferation and apoptosis in endometrial cancer cells. METHODS: Immunohistochemistry, western blot and RT-PCR were used to investigate the expressions of GLO-I protein and mRNA in endometrial cancer tissues and Ishikawa cell lines;enzyme activity of GLO-I in normal endometrium, endometrial cancer and paraneoplastic tissue samples was detected with spectrophotometer;proliferation and apoptosis of Ishikawa cell before and after RNA interference (RNAi) procedure were detected by the methyl thiazolyl tetrazolium (MTT) and flow cytometry, respectively. RESULTS: (1) There were significant differences of GLO-I expression between normal endometrium (0/19) and endometrial cancer tissues (76%, 22/29); these were also significant differences of enzyme activity of GLO-I among normal endometrium, paraneoplastic and endometrial cancer tissues (1.1, 0.8 vs 92.3 IU/mg; P < 0.01). Enzyme activity of GLO-I in fresh normal endometrium and paraneoplastic tissues was weak, while that of fresh endometrial cancer tissues was as high as 92.3 IU/mg in average. (2) The expression of GLO-I mRNA in Ishikawa cell transfected with GLO-I siRNA was significantly lower than that in negative group (0.25 ± 0.06 vs 0.93 ± 0.10, P < 0.01), and the similar results that in the expression of GLO-I protein (0.38 ± 0.06 vs 0.94 ± 0.13, P < 0.01). (3) Proliferation in Ishikawa cell was significantly inhibited after silencing RNA expression of GLO-I (P = 0.028). The apoptosis rate of cells transfected with GLO-I siRNA was significantly higher than that of negative control group and blank control group [(6.7 ± 0.8) % vs (1.2 ± 0.4)%, (1.4 ± 0.4)%; P < 0.01]. CONCLUSION: The expression and enzyme activity of GLO-I is significantly increased in endometrial cancer, which could promote abnormal proliferation and inhibit apoptosis in endometrial cancer cells.