人类胰岛素样生长因子—I调控子宫内膜癌细胞系孕激素受体亚型表达的研究

目的 探讨不同剂量人类胰岛素样生长因子－I（IGF－I）对子宫内膜癌细胞系中孕激素受体亚型表达的动态变化的调控。方法 体外培养子宫内膜癌细胞系HEC－IB,以乳腺癌细胞系MCF－7为对照,采用蛋白印迹（Western blot)法观察不同剂量IGF－I对两种孕激素受体亚型表达的动态变化的调控。结果 （1）HEC－IB细胞中,IGF－I 10ng/ml作用24h,人孕激素受体B亚型（hPRB)表达有明显上调作用,随着剂量的增加、作用时间的延长,pPRB表达逐渐下调,IGF－I 20ng/ml作用72h及40ng/ml作用48h时,下调最明显。人孕激素受体A亚型（hPRA)表达的变化趋势与hPRB大致相同,IGF－I为20ng/ml作用48h时下调至最低。（2）MCF－7细胞中,IGF－I 10、40ng/ml对hPRA、hPRB表达均有上调的作用,在第24、48、72h时较为明显。IGF－I 20ng/ml作用24h对hPRB表达有上调的作用,但在48、72h出现明显的下调;而对hPRA表达均为下调作用。结果 （1）IGF－I对人孕激素受体亚型的调控具有细胞特异性、以及时间和剂量的依赖性。（2）HEC－IB细胞中,IGF－I 10ng/ml作用24h对hPRA、hPRB表达有上调作用,随着剂量的增加、作用时间的延长,hPRA、hPRB表达渐下调。     

子宫内膜腺癌中孕激素受体亚型的表达

目的 研究子宫内膜癌中孕激素受体A、B、C三种亚型的表达,探讨其在子宫内膜癌发生、发展中的作用。方法 选取子宫内膜腺癌标本23例,其中高分化腺癌9例,中分化腺癌12例,低分化腺癌2例。另外选取绝经后子宫内膜标本5例。分别提取内膜或癌组织蛋白质,采用Western印迹法进行孕激素受体A、B、C三种亚型(hPRA、hPRB、hPRC)表达的半定量分析。结果 子宫内膜中、低分化腺癌与绝经后内膜对照相比,hPRB表达显著性降低(P=0.045);高分化腺癌和绝经后内膜hPRB差异无显著性(P>0.05)。中、低分化腺癌的hPRA、hPRB及hPRC低于高分化腺癌,但差异无显著性(P>0.05)。结论 子宫内膜中、低分化腺癌与绝经后内膜对照相比,hPRB显著下调,而高分化腺癌与绝经后内膜差异无显著性,提示hPBB可能与肿瘤的发生及分化程度有关。     

Differential gene expression in progesterone-sensitive and progesterone-insensitive endometrial carcinoma cells

High doses of progesterone are used in the treatment of advanced and recurrent endometrial cancer. Unfortunately the response rate is relatively low: 10-30%. The mechanisms involved in the development of insensitivity to progesterone treatment of endometrial cancer tissue are largely unknown. As tumour development is thought to be associated with a cascade of genetic alterations, it can be expected that genetic changes are involved in the development of progesterone insensitivity in endometrial carcinomas. We therefore started an investigation to identify, isolate and characterise progesterone-regulated genes involved in progesterone-induced growth inhibition in endometrial carcinoma cells. Using differential display PCR eight progesterone-regulated cDNA clones were identified in endometrial carcinoma cell lines. Four of these progesterone-regulated cDNA clones were regulated in the for growth progesterone-sensitive cell line IK-3H12 and not regulated in the for growth-insensitive cell line ECC-1. This indicates that these four cDNA clones represent potentially important genes, which could be involved in inhibition of growth of endometrial carcinoma tissue by progesterone.     

Molecular tools to reestablish progestin control of endometrial cancer cell proliferation

OBJECTIVE: Endometrial cancers often arise in a setting of estrogen stimulation unopposed by the differentiating effects of progesterone. Our laboratory and others have previously shown that progesterone receptor down-regulation or perturbation of progesterone receptor isoform A or B expression is associated with the development of poorly differentiated endometrial cancers that are not growth inhibited by progestins. The purpose of these studies was to reestablish high progesterone receptor isoform A and B gene expressions in such endometrial cancer cells and to examine the effects of progestin treatment on cell growth and metastatic potential after this transformation. STUDY DESIGN: To induce high levels of expression of the progesterone receptor isoforms in KLE and Hec50 endometrial cancer cells, adenoviral vectors encoding the genes for progesterone receptor isoforms A and B were created. The characteristic ability of cancer cells to grow independently of anchorage to the surrounding solid matrix was measured by counting colony formation on soft agar for 8 to 14 days. Cell proliferation in response to a time course of progestin treatment was tested with flow cytometry. RESULTS: After treatment with a control vector without a progesterone receptor--encoding insert, no effect of progestin treatment on cell proliferation was found; after treatment with vectors encoding progesterone receptor isoform A or B, however, progestin treatment resulted in significant inhibition of cell growth. The anchorage-independent cell growth on soft agar assay showed that by 8 to 14 days the number of cell colonies was reduced by 50% relative to control preparations in the presence of progesterone receptor isoform A plus progestin (P <.0001, both Hec50 and KLE cell lines) and by 90% in the presence of progesterone receptor isoform B plus progestin (P <.0001, both Hec50 and KLE cell lines). Progestin treatment also resulted in a time-dependent reduction in cell proliferation as measured by flow cytometry. Although transfection with both progesterone receptor isoforms A and B reduced cell proliferation according to our assays, progesterone receptor isoform B caused a much more dramatic decrease in cell growth (P =.001, Hec50 cells; P <.0001, KLE cells). CONCLUSION: In poorly differentiated endometrial cancer cells that are resistant to progestin therapy, adenovirus-induced expressions of progesterone receptors A and B reestablish progestin control of endometrial cancer cell proliferation.     

Progesterone-mediated regulation of catechol-O-methyl transferase expression in endometrial cancer cells

The effects of estrogen and progesterone on the expression of estrogen-metabolizing enzymes such as catechol-O-methyl transferase (COMT) are not known. COMT converts genotoxic catecholestrogens to anticarcinogenic methoxyestrogens in the endometrium. The aim of this study is to investigate the effect of progesterone on COMT expression in well-differentiated endometrial cancer cells. The wild-type Ishikawa cell line as well as progesterone receptor A- or progesterone receptor B-transfected Ishikawa cells were used for in vitro studies. The regulation of COMT expression by progesterone was studied using Western blots, Hoechst dye DNA proliferation studies, and wild-type and/or site-directed mutagenesis of COMT promoter 1-luciferase reporter gene. Progesterone upregulated COMT protein expression in Ishikawa cells through progesterone receptor A isoform. COMT promoter activity was differentially regulated by the 3 half-site progesterone response elements in the COMT promoter. High doses of 2-ME2 inhibited Ishikawa cell proliferation. These data suggest that COMT expression is hormonally regulated in well-differentiated human endometrial cancer cells. COMT regulation and 2-ME2 production in the endometrium may affect endometrial carcinogenesis.     

Progesterone receptor isoform identification and subcellular localization in endometrial cancer

OBJECTIVE: These studies were undertaken to characterize the subcellular localization of the two major isoforms of progesterone receptors (PR), PRA and PRB, in endometrial cancer. METHODS: Immunohistochemistry, immunoprecipitation, and confocal microscopy were performed using Hec50co and KLE endometrial cancer cell models expressing PRA or PRB as a consequence of transduction. The location of PRB compared to PRA was determined, and antibodies were tested for specificity with respect to PR isoform recognition. Immunohistochemical analyses of PR expression and subcellular compartmentalization were also performed on 20 formalin-fixed endometrial cancer tumors. RESULTS: Morphological and biochemical evaluations demonstrated that PRA is localized to the nucleus, even in the absence of progesterone. In contrast, a large proportion of PRB is cytoplasmic in the absence of ligand, but is rapidly translocated to the nucleus in the presence of progesterone. The differential distribution of PRA and PRB proved to be a hallmark of malignant and nonmalignant epithelia in 20 samples of archival endometrial tissue from women with the pre-operative diagnosis of endometrial cancer. All endometrial cancer specimens demonstrated cytoplasmic PRB in 50% or more of the cells, and five of the seven tumors that were moderately to poorly differentiated demonstrated no PRB staining in the nuclei. Nuclear PRB was significantly associated with increasing tumor differentiation (P = 0.031). CONCLUSION: In the absence of ligand, PRA is nuclear and PRB is largely cytoplasmic. This suggests that PRA may exert ligand-independent nuclear effects, while PRB may have nongenomic cytoplasmic actions in endometrial cancer cells.     

孕激素受体A、B亚型在子宫肌瘤中的表达

目的 旨在研究两种孕激素受体亚型 (hPR-A和hPR-B) 在子宫肌瘤和正常子宫肌层的分布及其mRNA的比例,探讨其在子宫肌瘤发生、发展中的意义。方法 选取22例因子宫肌瘤行全子宫切除术的标本,每1例取肌瘤组织和正常肌层组织,分别制成石蜡切片和冰冻标本。前者经免疫组化定位研究孕激素受体亚型;后者用于提取RNA,通过逆转录-多聚酶链反应,半定量研究孕激素受体亚型的mRNA表达。结果 免疫组化显示子宫肌瘤和正常肌层细胞的细胞核中,可见hPR及hPR-B的阳性颗粒;hPR-A、hPR-B和hPR-(A+B)的mRNA在肌瘤的表达量均高于周围正常肌层。无论在子宫肌瘤还是在正常肌层组织中,hPR-A与hPR-B的mRNA表达量无明显差异。结论 hPR-A、hPR-B为核受体;A亚型和B亚型的mRNA在子宫肌瘤表达高于正常肌层;孕激素受体亚型可能与子宫肌瘤的发生有关。     

Steroid-modulated proliferation of human endometrial carcinoma cell lines: any role for insulin-like growth factor signaling?

OBJECTIVES: Estrogen-stimulated proliferation of the normal and malignant human endometrium is balanced by the differentiating properties of progesterone. This study evaluated the role of insulin-like growth factor (IGF) signaling in steroid-induced modulation of endometrial cancer cell proliferation. METHODS: We used the human endometrial, estrogen-responsive ECC-1 and progesterone-responsive PRAB-36 cell lines. Proliferation studies with IGFs in combination with either estrogen or progesterone were conducted. Furthermore, the mRNA and protein expression of insulin-like growth factor-binding proteins (IGFBPs) was evaluated. RESULTS: Using the ECC-1 cell line, we observed that estrogen-induced proliferation is modulated via the IGF-receptor signaling pathway, and that IGF-1-induced stimulation of proliferation does not influence estrogen receptor signaling. Furthermore, expression of the main modulators of IGF action, the IGFBPs, was found to be regulated by estrogen and progesterone in both cell lines. IGFBP-4 was up-regulated by estrogen in the ECC-1 cell line, and IGFBP-3 and IGFBP-6 were down-regulated by progesterone in the PRAB-36 cell line. CONCLUSION: Estrogen-induced stimulation of proliferation of ECC-1 endometrial cancer cells is partly achieved via IGF signaling. Furthermore, the IGFBPs are regulated by estrogens as well as progestagens and could potentially play a role in the modulation of endometrial cancer cell proliferation.     

Danazol binds to progesterone receptors and inhibits the growth of human endometrial cancer cells in vitro

Based on our recent findings that danazol, an isoxazol derivative of ethinyltestosterone, has a profound growth-inhibitory effect on an established human endometrial adenocarcinoma cell line, the effects of danazol on cancer cells from human endometrial adenocarcinomas obtained by hysterectomy were investigated in the present study. Of the 22 uterine adenocarcinomas, estrogen, progesterone, and androgen receptors were found in 12, 14, and 4 tumors, respectively. Competitive binding studies showed that danazol specifically binds to progesterone and androgen receptors but not to estrogen receptors. Of the five cancer cells from five patients succeeded in primary cell culture, a marked inhibition of cell growth was demonstrated by addition of danazol in two cancer cells having progesterone but not androgen receptors. However, danazol did not affect the growth of the remaining three cancer cells lacking progesterone receptors. These results strongly suggest that danazol has a significant growth-inhibitory effect on human endometrial adenocarcinoma cells, possibly through progesterone receptors in the cells.     

雌/孕激素对原代培养的子宫内膜上皮细胞HOXA11和PR基因表达的影响

目的:探讨雌、孕激素（尤其孕激素）对人子宫内膜腺上皮细胞HOXA11基因和孕酮受体（pro-gesterone receptor,PR）基因表达的影响,以及二者表达量变化的相互关系。方法:将6例增生期子宫内膜腺上皮细胞进行原代培养,当细胞生长融合时,加入17β-雌二醇或/和孕酮培养4h、4d、6d、8d,提取细胞总RNA,用半定量RT-PCR法检测HOXA11mRNA和PRmRNA表达量变化。结果:17β-雌二醇使上皮细胞HOXA11和PR基因表达量增加;而孕酮的作用效应则有所不同,当孕酮作用于与间质细胞分离培养的上皮细胞时,其HOXA11的表达增加,当上皮与间质细胞混合培养时,孕酮则降低上皮细胞HOXA11表达;孕酮对PR的影响则显示无论分离培养还是与间质细胞混合培养的上皮细胞,孕酮均可使上皮细胞PRmRNA表达量降低。结论:子宫内膜HOXA11基因表达受雌、孕激素调节,孕激素对内膜腺上皮HOXA11和PR基因均起负调控作用,但二者的发生机制有所不同。     

子宫颈癌细胞亚克隆株细胞周期相关基因的研究

目的 探讨不同生长特性的人宫颈癌细胞亚克隆株CS03和CS07与其细胞周期相关基因的关系。方法 采用流式细胞仪对两株细胞进行细胞周期分析,用含有234条人类全长细胞周期相关基因的cDNA表达芯片,对两个同一来源、生长特性不同的人宫颈癌细胞亚克隆株CS03、CS07进行细胞周期相关基因的差异表达谱分析。结果 正常生长条件下培养的CS03细胞G1期百分比明显较CS07细胞高,而CS07细胞S期百分比则较CS03细胞有所增加;在无血清培养条件下CS03细胞在48h后凋亡（亚G1期）细胞百分比明显高于CS07细胞,并且随着时间的延长而增加。两个亚克隆细胞株CS03、CS07有3个差异表达基因,分别为人BN51 mRNA、人热休克蛋白90（hsp90)mRNA和Mcl-1基因,荧光强度的比值分别产0．480、0．479和0．490。结论 不同生长特性的宫颈癌细胞亚克隆株与其细胞周期相关基因BN51、hsp90和Mcl-1有密切关系。     

Medroxyprogesterone acetate stimulates cdk inhibitors, p21 and p27, in endometrial carcinoma cells transfected with progesterone receptor-B cDNA

PURPOSE OF INVESTIGATION: Progestin is reported to suppress the growth of endometrial carcinomas, although its precise mechanism of action is not clear. This study aimed to transfect progesterone receptor-B (PRB) cDNA into endometrial carcinoma cells and investigate the effect of medroxyprogesterone acetate (MPA) on cell growth, and p21 and p27 expression in the transfectant. METHODS: Immunoblotting for p21 and p27 was performed at predetermined times after the administration of MPA. RESULTS: PR expression was maximally induced in Ishikawa cells at 24 hrs after the transfection. At 1 x 10(-6) M, MPA suppressed the growth of the transfectant by 34% on day 6 and stimulated p21 accumulation at 48 to 72 hrs and p27 accumulation at 48 to 96 hrs after its administration. PRB cDNA was effectively transfected and in the transfectant MPA at 1 x 10(-6) M, the dosage suppressing growth, induced p21 and p27expression. CONCLUSION: p21 and p27 may be related to progesterone-induced growth suppression in human endometrial adenocarcinoma.     

子宫内膜癌中孕激素受体亚型表达及其甲基化状态的研究

目的:研究子宫内膜癌中孕激素受体亚型PRA、PRB表达与其启动子区甲基化状态的关系,探讨子宫内膜癌中孕激素受体亚型表达下调的机制。方法:(1)应用Real-Time PCR法检测子宫内膜癌及正常组织中孕激素受体亚型PRA、PRB mRNA的表达及去甲基化试剂5-Aza-CdR处理Ishikawa细胞前后孕激素两种受体亚型及DNA甲基化转移酶mRNA的表达;(2)应用甲基化特异性PCR(MS-PCR)检测子宫内膜癌细胞系Ishikawa中PRA、PRB的甲基化状态。结果:与正常子宫内膜组织比较,子宫内膜癌组织中,总PR表达显著降低,与病理类型相关;PRB表达显著下降,与其临床特征无关。子宫内膜癌细胞系Ishikawa中,加入5-Aza-CdR2.5μmol/L48h后,孕激素受体亚型PRA、PRB甲基化条带均消失;孕激素受体亚型PRA、PRB mRNA表达水平增加;同时Ishikawa细胞中DNA甲基转移酶DNMT1、DNMT3B表达下调。结论:子宫内膜癌组织中,孕激素受体亚型mRNA表达下调可能与子宫内膜癌的发生相关;孕激素受体亚型表达下调与其启动子区甲基化状态相关;去甲基化试剂5-Aza-CdR可逆转基因启动子区的甲基化状态,恢复PR基因的表达。     

EGFR过表达降低人子宫内膜癌细胞孕激素敏感性的研究

目的:检测表皮生长因子受体(EGFR)基因在子宫内膜癌孕激素敏感细胞株Ishikawa及孕激素不敏感细胞株KLE的表达,探讨EGFR基因过表达对人子宫内膜癌细胞孕激素敏感性的影响。方法:实时定量PCR法和蛋白印迹法检测Ishikawa和KLE细胞中EGFR及PR-BmRNA和蛋白的表达。将EGFR全长cDNA真核表达质粒在脂质体介导下转染至Ishikawa细胞,同时以转染空载体和未转染的Ishikawa细胞为对照,分别应用实时定量PCR检测各组细胞EGFR、PR-BmRNA表达的变化,应用蛋白印迹法检测各组细胞EGFR、PR-B蛋白表达的变化;CCK-8法观察转染EGFR基因后Ishikawa细胞对孕激素敏感性的变化。结果:(1)Ishikawa细胞中,EGFRmRNA和蛋白的表达明显低于KLE细胞(P<0.001),而PR-BmRNA和蛋白的表达则显著高于KLE细胞(P<0.001);(2)稳定转染EGFR基因后,Ishikawa细胞中EGFRmRNA和蛋白的表达水平明显高于转染空载体和未转染的Ishikawa细胞(P<0.001),而PR-BmRNA和蛋白的表达水平则显著降低;(3)10-8、10-7、10-6、10-5mol/L的MPA对未转染和转染空载体的Ishikawa细胞的抑制作用显著(P<0.05),但对稳定过表达EGFR的Ishikawa细胞无明显抑制作用(P>0.05)。结论:转染EGFR基因能有效提高Ishikawa细胞内EGFR基因的表达,但可下调PR-B基因的表达使Ishikawa细胞对MPA不敏感。     

二甲双胍对人子宫内膜癌细胞迁徙能力的影响

目的：体外检测二甲双胍对人子宫内膜癌（Ec）细胞迁徙能力的影响,并探讨其可能的作用机制。方法：培养Ishikawa和HEC-1A人子宫内膜癌细胞系,用不同浓度的二甲双胍干预EC细胞。采用划痕试验检测细胞迁徙能力;流式细胞术检测细胞周期和凋亡;Western blot法检测Akt、p-Akt及PTEN的表达。结果：二甲双胍显著抑制Ishika—wa和HEC-1A细胞的迁徙能力（P均〈0．05）。流式细胞术检测显示,二甲双胍使G0／G1期细胞比例显著升高,同时有凋亡诱导作用;Westernblot法检测显示,二甲双胍能下调P—Akt的表达（P均〈0．05）。结论：二甲双胍显著抑制EC细胞的迁徙能力,其作用机制可能与下调p-Akt的表达有关。