神经内分泌分化对前列腺癌细胞生长及雄激素受体表达影响的实验研究

目的探讨神经内分泌分化对前列腺癌细胞生长的作用及对雄激素受体表达的影响。方法建立神经内分泌分化的前列腺癌细胞模型PC3MNE和LNCaPNE;采用甲基噻唑基四唑(MTT)试验观察其调节前列腺癌细胞生长的作用[以吸光度值(A)表示];采用逆转录聚合酶链反应和Western杂交方法检测LNCaPNE对LNCaP细胞雄激素受体表达的影响。结果PC3MNE的培养上清液可促进PC3M细胞的生长(A值在培养24h为034±018与050±009,48h为038±016与057±009,72h为038±015与055±005,P均<005);在有雄激素时,LNCaPNE的培养上清液不促进LNCaP细胞的生长,对其雄激素受体的表达也没有显著影响;去除雄激素后,LNCaPNE的培养上清液可促进LNCaP细胞的生长,并能下调其雄激素受体的表达(P均<005)。结论在雄激素阻断后,神经内分泌分化的前列腺癌细胞能以旁分泌的方式支持其他前列腺癌细胞生长,降低其雄激素受体的表达。     

表皮生长因子受体在前列腺癌雄激素非依赖型细胞系中表达的意义

目的探讨转化生长因子(TGF)-α和表皮生长因子(EGF)对前列腺癌雄激素非依赖型细胞系中表皮生长因子受体(EGFR)表达的调控作用.方法采用逆转录-多聚酶链式反应和免疫印迹法分别对TGF-α和EGF刺激前列腺癌雄激素非依赖型细胞系PC3、ARCaP后EGFR mRNA表达及其蛋白水平进行定量分析.结果EGF引起PC3、ARCaP的EGFR mRNA升高,分别为5.01±0.45和2.41±0.26,差异无显著性(P＞0.05);TGF-α引起各细胞系EGFR mRNA升高,分别为9.05±0.63和3.54±0.33,差异无显著性(P＞0.05).各细胞系EGFR蛋白水平TGF-α组明显高于EGF组(P＜0.05).结论TGF/EGF-EGFR通路在发生发展中起重要作用;TGFα-EGFR自分泌环在非依赖型前列腺癌中的作用强于EGF-EGFR自分泌环.     

反义寡核苷酸阻断雄激素受体表达对前列腺癌细胞生长活性的影响

目的　探讨反义技术阻断雄激素受体 (AR)基因表达对前列腺癌细胞生长的影响。　方法　设计、合成针对AR基因反义寡核苷酸 (ASODN) ,在脂质体介导下转染前列腺癌细胞。采用RT PCR方法检测AR基因表达 ;MTT比色法检测细胞增殖活性 ;透射电镜、TUNEL检测细胞凋亡 ;流式细胞术分析细胞周期时相。　结果　 0 .5～ 2 .0 μmol LASODN作用 12～ 36h ,癌细胞ARmRNA水平降低 10 .45 %～ 82 .10 %(P <0 .0 5 ) ,细胞增殖活性抑制 11.8%～ 5 6 .9%(P <0 .0 5 ) ,细胞周期阻滞于G2 M期 ,部分细胞呈现典型凋亡形态学改变 ,凋亡比率为 34.2 5 %(P <0 .0 1)。　结论　应用ASODN封闭AR基因表达能抑制前列腺癌细胞体外生长活性 ,有望成为前列腺癌基因治疗的有效策略。     

表皮生长因子受体阻断对前列腺癌细胞增殖的影响

目的：探讨阻断表皮生长因子受体（EGFR）对前列腺癌（PCa）细胞增殖的影响。方法：人PCa细胞株DU－145，分别加或不加抗EGFR单抗C225（20nmol/L)阻断EGFR体外细胞培养7d，收集细胞、计数以观察对PCa雄激素非依赖增殖的影响，并采用免疫沉淀和Western blot方法，探讨阻断EGFR后不同时相点磷酸化有丝分裂原激活下蛋白激酶MAPK，及p27^kipl的表达变化。结果：阻断EGFR与对照相比较可使DU－145细胞增殖被抑制达35％，8h后磷酸化MAPK的表达水平开始降低，p27^kip1表达开始升高，至24h最明显。结论：阻断EGFR可抑制PCa细胞增殖，可能的机制是MAPK的活性降低，使p27^kip1的表达升高而细胞周期被阻。     

Clinical effects of gonadotropin-releasing hormone analogue in metastatic carcinoma of prostate

Leuprolide is a new, potent analogue of gonadotropin-releasing hormone which, after an initial transient stimulation, causes a profound suppression of serum gonadotropins and testosterone. One hundred eighteen patients with advanced carcinoma of the prostate have undergone treatment with leuprolide in a multi-institutional trial. Minimal evidence of objective response was seen in patients who had failed prior endocrine therapy with orchiectomy or estrogens. In patients without previous hormonal treatment, leuprolide induced an objective disease response (72%) comparable to alternative primary endocrine therapy. Considering the lack of significant side effects seen with long-term GnRH agonists, compounds such as leuprolide may prove to be the preferred initial endocrine therapy for selected patients with metastatic carcinoma of the prostate.     

Density-dependent regulation of epidermal growth factor receptor expression in DU 145 human prostate cancer cells

Androgen-independent prostate cancer cells may rely on an autocrine loop for growth stimulation, and have been shown to express both the epidermal growth factor receptor (EGFR) and its stimulatory ligands. We have shown here that DU 145 prostate cancer cells have a decreased amount of EGFR in confluent cultures when compared to levels seen in subconfluent cultures. This down-regulation of EGFR numbers is not due to cell proliferation or nutrient depletion, but can be correlated only with whether cell-cell contact exists throughout the culture. This is reminiscent of the situation existing in some tumors whereby EGFR expression is higher in cells at the invading margins of the tumor.     

Adenovirus-mediated expression of a soluble fibroblast growth factor receptor inhibits in vitro growth of prostate DU145 cells

BACKGROUND: Fibroblast growth factor (FGF) family plays a key role in prostate cancer. The soluble FGF receptor (sFGFR) has been studied with regards to inhibiting cancer growth and was shown to have a dominant negative effect on cellular signaling and function. Using replication deficient adenovirus-mediated gene transfer, we tested if sFGFR expression may have a suppressive effect on in vitro growth of prostate cancer cells. METHODS: Western analysis was used to verify expression of sFGFR1 and to examine the effect of sFGFR1 on MAP kinase phosphorylation. The effect on proliferation and invasiveness of DU145 cells was examined using the WST-1 and Matrigel Invasion assay, respectively. RESULTS: Activation of MAP kinase (pERK1 and 2) by exogenous FGF1, 2, and 7 was suppressed to baseline levels by sFGFR, which was not seen with EGF. Proliferation and invasion of DU145 cells were significantly suppressed by sFGFR. CONCLUSIONS: A replication deficient adenoviral vector system reproducibly expresses sFGFR in prostate cells. Suppression of in vitro growth in DU145 cells by sFGFR provides the basis of a novel therapeutic approach.     

Circulating growth hormone binding protein levels and mononuclear cell growth hormone receptor expression in uremia.

BACKGROUND: Resistance to growth hormone (GH) in end-stage renal disease (ESRD) causes growth retardation and muscle wasting. In humans, circulating GH binding protein (GHBP), the extracellular domain of the GH receptor that is shed into the circulation and is believed to reflect tissue GH receptor levels, is reduced in uremia and suggests that cellular GH receptor levels are correspondingly reduced. If true, this could be a cause of GH resistance. We set out to establish whether serum GHBP levels reflect cellular GH receptor levels and whether changes in serum GHBP levels are related to nutritional or inflammatory status. METHODS: GH receptor protein expression in peripheral blood mononuclear cells (PBMC) from 21 ESRD and 14 normal subjects were analyzed by fluorochrome flow cytometry. RESULTS: The GH receptor density and percent total PBMCs expressing the GH receptor were similar in the 2 groups, and there was no difference in percent GH receptor positive T or B cells or monocytes. In contrast, serum GHBP levels were 80% lower in ESRD. GHBP levels did not correlate with serum albumin, body mass index, or muscle mass but seemed to be partly related to the log serum C-reactive protein levels. CONCLUSIONS: Serum GHBP levels are markedly reduced in ESRD; this seems to occur independent of nutritional status and may in part be caused by inflammation. Because GH receptor expression on PBMC of ESRD and control subjects was similar, our findings argue against a reduction in GH receptor as a cause of GH resistance and the use of serum GHBP levels as a reliable marker of specific tissue GH receptor levels.     

Inhibition of SULT2B1b expression alters effects of 3beta-hydroxysteroids on cell proliferation and steroid hormone receptor expression in human LNCaP prostate cancer cells

BACKGROUND: Sulfation is an important steroid inactivation in human tissues. Sulfotransferase (SULT) 2B1b selectively conjugates 3beta-hydroxysteroids and is expressed in epithelial cells of normal and cancerous prostate tissues. Dehydroepiandrosterone (DHEA) and Delta(5)-androstenediol (Delta(5)-Adiol) sulfation prevents their conversion to more potent androgens and estrogens in tissues although both compounds may also be biologically active. METHODS: SULT2B1b expression and activity were inhibited >85% in human LNCaP prostate adenocarcinoma cells using short interference RNA (siRNA). The effects of treating control and SULT2B1b-deficient LNCaP cells with DHEA, Delta(5)-Adiol, and 5alpha-androstane-3beta-17beta-diol (Anstane-diol) on cellular proliferation, estrogen receptors (ERs), androgen receptor (AR), and prostate specific antigen protein levels were examined. RESULTS: Physiological concentrations of DHEA and Delta(5)-Adiol increased proliferation of control cells and the proliferative effects were significantly increased in SULT2B1b-siRNA cells. DHEA, but not Delta(5)-Adiol increased AR levels at concentrations >/=1,000 nM in SULT2B1b-siRNA cells but not in control LNCaP cells. ER-alpha levels were not affected with any of the compounds tested. Physiological concentrations of DHEA and Delta(5)-A-diol decreased ER-beta levels in control cells and had significantly greater effects in SULT2B1b-siRNA cells. In contrast, Anstane-diol had no effect on AR or ER-alpha levels but induced more elevation of ER-beta levels in SULT2B1b-siRNA cells at concentrations >/=1,000 nM. CONCLUSIONS: SULT2B1b is involved in regulating prostate cell responsiveness to DHEA and Delta(5)-Adiol. Inhibition of SULT2B1b increased cell proliferation and ER-beta repression after treatment with physiological levels of DHEA and Delta(5)-Adiol indicating that SULT2B1b has an inhibitory effect on DHEA and Delta(5)-Adiol activity.     

重组生长激素对应激状态下鼠肝生长激素受体mRNA表达及肝脏再生的影响

目的 初步探讨重组生长激素（ｒＧＨ）改善肝切除术后疲劳结合征（ＰＯＦ）的分子机制及对肝脏再生的影响。方法 采用半定量逆转录聚合酶链式反应（ＲＴ－ＰＣＲ）技术,分别对治疗组及对照组大鼠切肝４０％术后３,７ｄ生长激素受体ｍＲＮＡ（ＧＨＲｍＲＮＡ）的表达及相对肝重量（肝重／体重）进行研究。结果 手术宾３ｄ组ＧＨＲ ｍＲＮＡ表达量明显下降;治疗组术后３ｄ ＧＨＲｍＲＮＡ的表达术后７ｄ肝脏再生且明显增加（Ｐ     

生长激素受体在直肠癌组织中的表达

目的 研究生长激素受体(GHR)在直肠癌患者癌组织和正常直肠组织中的表达情况.方法 收集接受直肠癌根治术且手术断端无肿瘤转移患者的直肠癌标本43例.按癌细胞分化程度分成高、中、低3组,癌组织及远端断端正常直肠组织用免疫组化法行GHR染色.结果 中分化组1例直肠癌患者断端正常直肠黏膜GHR染色为可疑阳性,其余患者癌组织及断端直肠黏膜GHR染色均为阳性.低分化组直肠癌组织中GHR的表达水平明显高于中分化组和高分化组(P<0.05),中分化组GHR表达亦高于高分化组,但无统计学意义(P>0.05);高分化组断端正常直肠黏膜GHR表达水平显著低于中分化组和低分化组(P<0.05),中分化组正常直肠黏膜GHR表达低于低分化组,但无统计学差异(P>0.05).各组癌组织与断端正常直肠黏膜GHR表达无显著性差异(P>0.05).结论 直肠癌患者癌组织和断端正常直肠粘膜的GHR表达水平基本一致,随着直肠癌细胞分化程度的降低,GHR在癌组织及断端正常直肠黏膜中的表达有增高的趋势.     

Restoration of fibroblast growth factor receptor2 suppresses growth and tumorigenicity of malignant human prostate carcinoma PC-3 cells

BACKGROUND: Fibroblast growth factors (FGFs) and their receptors (FGFRs) expedite stromal-epithelial communication in development and homeostasis of the human prostate. Loss of resident epithelial cell FGFR2IIIb that responds to stromal FGF7 and FGF10 accompanies malignant progression of both model animal and human prostate tumors. METHODS: We examined whether restoration of FGFR2IIIb by transfection in the malignant human prostate tumor PC-3 cell line restored cellular properties associated with less malignant tumors. Cell proliferation, apoptosis, and tumor cell implants were used to monitor malignant properties. Activity of FGFR2IIIb was assessed by immunoblot of FRS2 and p44/42 MAP kinase. Immunochemical analysis of pancytokeratin and lactoferrin expression was utilized to assess changes in cellular differentiation. RESULTS: Expression of FGFR2IIIb in PC-3 cells by transfection resulted in growth suppression in vitro and reduced tumor formation in vivo concurrent with increased cellular differentiation and apoptosis. CONCLUSIONS: The results indicate that restoration of FGFR2IIIb to the malignant human prostate epithelial cell prototype PC-3 restores properties associated with nonmalignant tumors and normal cells. This further suggests that epithelial cell resident, homeostasis-promoting FGFR2 may be involved in suppression of malignancy and that restoration may be a candidate for gene therapy of hormone-refractory prostate cancer.     

人生长激素受体在结肠癌组织中的表达及其临床意义

目的:研究生长激素受体(growth hormone receptor,GHR)在人结肠癌组织中的表达水平,为临床结肠癌患者术后合理使用重组人生长激素(rhGH)提供理论依据。方法:应用免疫组织化学方法对结肠癌组织及其癌组织远端10cm的正常结肠组织进行GHR的检测,研究GHR在不同的病理类型、分期,不同分化程度结肠癌组织中的表达水平。结果:GHR在结肠癌组织中阳性表达率明显高于正常的结肠组织,且GHR的表达在不同的临床分型、分期和分化程度上差异显著。结论:GHR在结肠癌组织中呈高表达;结肠癌根治术后的患者化疗时配合使用rhGH可能增强治疗效果。     

甲状腺素及受体与心肌缺血

亚临床甲状腺功能减退被认为与冠心病发病率和心脏疾病死亡密切相关,新近研究发现甲状腺素(tlhryroid hormone,TH)对缺血心肌有保护作用,现从甲状腺素及其受体角度阐述其机制.