Evaluation of urine biomarkers of kidney injury in polycystic kidney disease

Progressive disruption of renal tubular integrity in the setting of increased cellular proliferation and apoptosis is a feature of autosomal dominant polycystic kidney disease (ADPKD). Here we evaluated the effect of these processes on the expression of Lcn2 (NGAL) and interleukin (IL)-18, markers of tubular injury, in rodent models and in the cyst fluid and urine of patients with ADPKD. Two mouse models where Pkd2 was inactivated, which resulted in early- or adult-onset cysts, were used to evaluate NGAL levels. Further, the Han:SPRD rat model of polycystic disease was used to study IL-18 levels. In four annual serial urine samples collected from 107 patients with ADPKD in the Consortium for Radiologic Imaging for the Study of Polycystic Kidney Disease (CRISP) study, NGAL and IL-18 excretion rates were determined in conjunction with measures of total kidney volume and estimated glomerular filtration rate (eGFR) by the Modification of Diet in Renal Disease equation. Kidneys from affected mice and rats showed prominent expression of NGAL and IL-18/IL-18R, respectively, in epithelial cells lining kidney cysts. In human ADPKD cyst fluid, both NGAL and IL-18 were elevated. In CRISP patients, the mean percentage increase in total kidney volume was 5.4/year and the mean decline in eGFR 2.4?ml/min/year. The trend of increased mean urine NGAL and IL-18 over 3 years was statistically significant; however, there was no association between tertiles of IL-18 or quartiles of NGAL and change in total kidney volume or eGFR over this period. Thus, urinary NGAL and IL-18 excretion is mildly and stably elevated in ADPKD, but does not correlate with changes in total kidney volume or kidney function. This may be due, in part, to the lack of communication between individual cysts and the urinary collecting system in this disorder.     

cAMP regulates cell proliferation and cyst formation in autosomal polycystic kidney disease cells

Both epithelial cell proliferation and fluid accumulation are responsible for cyst growth in autosomal dominant polycystic kidney disease (ADPKD). It was previously reported that the cystic fibrosis transmembrane conductance regulator (CFTR) is expressed in cysts from ADPKD patients and suggested that cAMP-stimulated Cl(-) and fluid secretion occurs through CFTR. The purpose of this study was to investigate the role of cell proliferation in cyst formation in ADPKD and to explore further the role of fluid secretion in cyst growth. Primary cultures both of ADPKD epithelial cells and a mixed population of normal renal epithelial cells isolated from the cortex (HRCE cells) were used. This study tested whether cAMP was involved both in stimulating cell proliferation and formation of cysts in vitro. (3)H-Thymidine incorporation assays showed that epidermal growth factor stimulated proliferation both in ADPKD cells and HRCE cells. In addition, cAMP stimulated DNA synthesis and cell proliferation in ADPKD, but not HRCE, cells. The effects of cAMP and epidermal growth factor on cell growth in ADPKD cells were additive. cAMP also stimulated cyst enlargement and fluid secretion in ADPKD cells. By contrast, cyst formation and enlargement from HRCE cells occurred without cAMP. Fluid secretion into the cyst lumen was blocked by diphenylamine carboxylic acid (DPC) and glibenclamide in ADPKD cells but blocked only by DPC in HRCE cells. This study showed that ADPKD cells have unique characteristics; cAMP stimulates fluid secretion and cell proliferation, indicating cAMP plays a very important role in cyst growth during the course of ADPKD.     

ErbB-4 may control behavior of prostate cancer cells and serve as a target for molecular therapy

PURPOSE: To assess ErbB-4 expression in advanced human prostate cancer (PC) cell lines, the role of ErbB-4 in motility, migration, and proliferative/tumorigenic potential of PC cells, and efficacy of anti-ErbB-4 monoclonal antibody (Mab) treatment on PC cells in vitro and tumor growth in vivo. MATERIALS AND METHODS: Established advanced human PC cell lines (PC-3, Cl-1, and Du-145) were evaluated for ErbB-4 expression. Several Cl-1 cell line clones expressing various levels of ErbB-4 were isolated, their motility, migration capacity, and in vitro proliferation as well as survival following Mab treatment were evaluated. Tumorigenicity and proliferation capacity of these clones in vivo and efficacy of Mab treatment on tumor growth were estimated by measurements of subcutaneous tumors developed in nude mice. RESULTS: PC cell lines studied express ErbB-4. Both PC-3 and Du-145 cell lines express high ErbB-4 levels; only 50% of Cl-1 cells express ErbB-4 with large heterogeneity. Cl-1 sub-clones highly expressing ErbB-4 showed increased cell motility, migration, and proliferation rate in vitro and enhanced growth in vivo, compared to clones with low ErbB-4 expression. Mab treatment inhibited the growth of cells expressing high but not low ErbB-4 levels in vitro and decreased the growth of subcutaneous tumors in nude mice generated by ErbB-4 highly expressing cells. CONCLUSIONS: High expression of ErbB-4 in prostate cancer Cl-1 cell clones correlated with high proliferative and migration capacity and high tumorigenic potential. The inhibitory effect of Mab on cell proliferation and on subcutaneous tumor growth suggests ErbB-4's potential as a target for molecular anticancer therapy.     

原癌基因N-MYC下游调节基因-2对前列腺癌细胞株PC3的体外增殖抑制作用

目的 观察原癌基因N-MYC下游调节基因-2(NDRG2)在不同前列腺癌细胞株中的表达水平和对PC3细胞的体外增殖抑制作用.方法 采用逆转录-聚合酶链反应(RT-PCR)及Western blot检测不同前列腺癌细胞株(PC3、LNCaP、DU145)的NDRG2表达水平,使用pAD_CMV腺病毒感染的方法 观察NDRG2对PC3细胞的作用,乳糖操纵子z(Lacz)为阳性对照,并设空白对照,噻唑蓝比色法(MTT法)绘制细胞生长曲线、流式细胞仪(FCM)检测感染48、72 h的细胞周期及凋亡.结果 3个前列腺癌细胞株的NDRG2表达水平相对较低,其中PC3细胞表达水平最低,细胞生长曲线显示NDRG2基因自感染36h开始能够抑制PC3细胞增殖(F≥12.43,P＜0.01),FCM检测发现,感染72 h时,包装有NDRG2基因腺病毒感染组同空白及阳性对照组比较,细胞G1期阻滞(3组分别为68.06%、50.33%和50.33%),细胞凋亡增加(3组分别为12.33%、3.21%和3.87%).结论 NDRG2基因可能参与了前列腺癌的发病,腺病毒介导的人NDRG2基因可明显抑制PC3细胞的增殖.     

Chemical modification of cell proliferation and fluid secretion in renal cysts

We used an in vitro model, MDCK cyst, to determine the extent to which pharmacologic compounds known to inhibit plasma membrane solute transport mechanisms could alter the enlargement of renal epithelial cysts. Solitary MDCK cells cultured within collagen gel undergo clonal growth to form true epithelial cysts in which a single layer of polarized cells (apex toward lumen) encloses a fluid-filled cavity. Repeated observations by light microscopy were used to quantitate the rate of cyst growth in diameter, and demonstrated that cyst enlargement involved an increase in cell number (proliferation) and a net increase in intracystic volume (fluid secretion). Intracyst pressure was greater than the interstitium (6.7 mm H2O +/- 3.1 SD), indicating that fluid entry was secondary to net solute accumulation. Amiloride and seven amiloride analogs that inhibited to different degrees conductive Na+ transport, Na+-dependent H+ transport and Na+-dependent Ca++ transport reversibly decreased the rate of cyst enlargement. The effectiveness of these agents to retard cyst enlargement correlated with their relative potencies to inhibit Na+-dependent Ca++ transport. Morphologic examination indicated that amiloride and amiloride analogs decreased cell proliferation and fluid secretion to the same degree. Ouabain and vanadate (Na+K,ATPase inhibitors), and L-645,695 (Na+-dependent Cl-/HCO3- inhibitor) potently slowed cyst expansion. In contrast to amiloride and amiloride analogs, these agents caused an unusual degree of cellular stratification within the cyst walls, a finding consistent with the notion that fluid secretion was inhibited to a greater extent then cellular proliferation. We conclude that chemical inhibitors of primary and secondary active solute transport can diminish or halt the enlargement of epithelial cysts in vitro by decreasing the rate of cellular proliferation and/or net fluid secretion.     

塞来昔布对PC12细胞的凋亡作用及对血管内皮生长因子表达的影响

目的体外探讨COX-2抑制剂塞来昔布对PC12细胞的生长影响及血管内皮生长因子VEGF的表达的调控。方法应用噻唑蓝（MTT）比色法观察塞来昔布对大鼠嗜铬细胞瘤细胞系PC12细胞的生长抑制作用;Wrights-Giemsa染色法观察细胞形态学;流式细胞技术观察细胞在各时间点的凋亡率;Western blot检测VEGF-165蛋白的表达变化。结果塞来昔布呈时间、剂量依赖性抑制PC12细胞,24h半数抑制浓度（IC50）为100μmol/L;各点凋亡率均高于空白对照组;塞来昔布能抑制PC12细胞的VEGF-165蛋白表达,且跟时间正相关。结论 COX-2抑制剂塞来昔布能抑制PC12细胞增殖,诱导细胞凋亡,抑制VEGF蛋白表达。     

Triptolide reduces cystogenesis in a model of ADPKD

Mutations in PKD1 result in autosomal dominant polycystic kidney disease, which is characterized by increased proliferation of tubule cells leading to cyst initiation and subsequent expansion. Given the cell proliferation associated with cyst growth, an attractive therapeutic strategy has been to target the hyperproliferative nature of the disease. We previously demonstrated that the small molecule triptolide induces cellular calcium release through a polycystin-2-dependent pathway, arrests Pkd1(-/-) cell growth, and reduces cystic burden in Pkd1(-/-) embryonic mice. To assess cyst progression in neonates, we used the kidney-specific Pkd1(flox/-);Ksp-Cre mouse model of autosomal dominant polycystic kidney disease, in which the burden of cysts is negligible at birth but then progresses rapidly over days. The number, size, and proliferation rate of cysts were examined. Treatment with triptolide significantly improved renal function at postnatal day 8 by inhibition of the early phases of cyst growth. Because the proliferative index of kidney epithelium in neonates versus adults is significantly different, future studies will need to address whether triptolide delays or reduces cyst progression in the Pkd1 adult model.     

Flavopiridol对尤文肉瘤SK-N-MC细胞增殖的抑制作用

目的探讨细胞周期蛋白激酶抑制剂（flavopiridol）在体内外抑制尤文肉瘤细胞增殖的作用及其机制。方法以不同浓度的flavopiridol作用于培养的SK-N-MC细胞,用噻唑蓝法（MTT）检测细胞增殖,流式细胞分析仪测定细胞周期。采用DNA凝胶电泳检测法,观察flavopiridol诱导细胞凋亡的情况;蛋白质电泳观察Bcl-2及Mcl-1表达变化;建立SK-N-MC细胞裸小鼠皮下移植瘤模型,腹腔内给药,观察肿瘤生长情况;肿瘤标本石蜡包埋切片,免疫组织化学原位末端标记法（TUNEL）检测flavopiridol在体内对肿瘤细胞的凋亡诱导情况。结果（1）Flavopiridol对人尤文肉瘤细胞增殖有抑制作用,时间越长、浓度越高,抑制作用越强。（2）Flavopiridol可改变尤文肉瘤细胞周期,随药物浓度增加Sub-G1期百分比逐渐上升。尤文肉瘤细胞经flavopiridol中、高浓度给药后,DNA凝胶电泳可见典型的梯状带。（3）Flavopiridol给药前后,Bcl-2蛋白表达无变化,而Mcl-1蛋白表达明显下降。（4）TUNEL染色结果显示实验组阳性细胞比例上升,与对照组比较差异有统计学意义。结论Flavopiridol能在体内外抑制尤文肉瘤细胞的增殖,其机制主要是阻滞细胞周期的G1/S期,诱导细胞凋亡。     

Activin A Causes Cancer Cell Aggressiveness in Esophageal Squamous Cell Carcinoma Cells

BACKGROUND: Expression of activin A is associated with lymph node metastasis and clinical stage in esophageal cancer. METHODS: To clarify the aggressive behavior of tumors with high activin A expression, we used the beta subunit of activin A to establish stable activin betaA (Act-betaA)-transfected carcinoma cells in two human esophageal carcinoma cell lines, KYSE110 and KYSE140. The biological behavior of these cells was compared with that in mock-transfected cells from the same cell lines. We focused our attention on cell growth and tumorigenesis, and proliferation and apoptosis. RESULTS: Both Act-betaA-transfected carcinoma cell lines showed a higher growth rate than the mock-transfected carcinoma cells. In an in vitro invasion assay and a xenograft analysis, the Act-betaA-transfected carcinoma cells showed far higher proliferation in vitro and a higher potency for tumorigenesis in vivo, respectively. Moreover, in an analysis of apoptosis via Fas stimulation, the Act-betaA-transfected carcinoma cells showed a higher tolerance to apoptosis compared with the mock-transfected carcinoma cells. Moreover, anti-activin-neutralizing antibody-treated squamous cell cancer cell lines inhibited their migration. CONCLUSIONS: Collectively, these data indicate that continuous high expression of activin A in esophageal carcinoma cells is not related to tumor suppression, but rather to tumor progression in vitro and in vivo. The inhibition of activin might be one of the methods to attenuate tumor aggressiveness.     

Aberrant epithelial cell growth in autosomal dominant polycystic kidney disease

Renal cyst enlargement in autosomal dominant polycystic kidney disease (ADPKD) is characterized by increased epithelial cell proliferation and fluid accumulation. Using monolayer epithelial cultures derived from individually microdissected human ADPKD cysts and immunolocalization studies in vivo, the roles of matrix and growth factors in aberrant ADPKD cell proliferation have been studied. Abnormal ADPKD basement membrane ultrastructure was associated with increased turnover of 35S-labeled heparan sulfate proteoglycans (HSPG) by comparison to normal renal tubule epithelia in vitro. Mitogenic assays demonstrated significant increase in 3H-thymidine incorporation into ADPKD epithelia grown on type I and type IV collagen by comparison to normal proximal straight tubules (PST), collecting ducts, and thick ascending limbs of Henle (TAL). Proliferation on laminin or fibronectin matrices was unchanged and immunolocalization of matrix proteins was polarized and restricted to basal membranes of both ADPKD cysts and renal tubule epithelia in vivo. ADPKD epithelia in vitro were hypersensitive to the mitogenic action of epidermal growth factor (EGF) and EGF immunoreactivity was detected in ADPKD cyst lining epithelia, in cyst fluid, and in conditioned media from confluent ADPKD cultures, suggesting an autocrine mechanism of growth regulation. In addition, inhibition of epithelial proliferation by transforming growth factor-beta (TGF-beta), which was 100% in normal renal tubule epithelia, was reduced to 41% in ADPKD epithelia.     

Cyst fluid from human autosomal dominant polycystic kidneys promotes cyst formation and expansion by renal epithelial cells in vitro.

Autosomal dominant polycystic kidney disease (ADPKD) is characterized by progressive renal enlargement, culminating in renal insufficiency in over one half of affected individuals. The highly variable onset and clinical course of ADPKD may be due to factors extrinsic to the genetically defined renal cysts. In this study, cyst fluid samples from 12 nonazotemic and 18 azotemic ADPKD subjects were examined for in vitro biologic activity that promotes cellular proliferation and the secretion of fluid by renal epithelial monolayers, two pathogenetic mechanisms that have critical roles in the formation and the rate of expansion of renal cysts. Cyst fluid added to culture medium (final concentrations, 1 to 20%) caused Madin-Darby canine kidney cells and human kidney cortex (HKC) cells derived from primary cultures to form cysts in Type I collagen matrix. Cyst fluid stimulated the net transepithelial secretion of fluid by polarized monolayers composed of these same cells. Absolute levels of fluid secretory activity determined by MDCK bioassay were correlated directly with the rate of fluid secretion by HKC cell monolayers and with the extent of cyst formation by MDCK and HKC cells embedded in collagen matrix. The secretory activity of urine was negligible; secretory activity was detectable in the serum of normal and ADPKD subjects, but the levels were much lower than in cyst fluid. cAMP agonists prostaglandins E1 and E2, arginine vasopressin, and 8-Br-cAMP stimulated fluid secretion by MDCK and HKC monolayers, but these substances did not cause HKC cells to form cysts in collagen matrix, whereas cyst fluid did. Among other naturally occurring growth factors and autacoids, only epidermal growth factor and transforming growth factor alpha stimulated cyst formation by HKC cells; however, the capacity of cyst fluid to stimulate fluid secretion was not affected by treatment with antiserum to epidermal growth factor. It was concluded that potent, and possibly unique, substances in the cyst fluids of individuals with ADPKD support and augment biologic processes in renal epithelial cells that may be important in the promotion of progressive cyst expansion.     

Role of keratinocyte growth factor in the pathogenesis of autosomal dominant polycystic kidney disease.

BACKGROUND: Previous studies have shown that the expression and distribution of keratinocyte growth factor (KGF), also known as FGF-7 (fibroblast growth factor-7) or HBGF-7 (heparin-binding growth factor-7), may be implicated in kidney cyst formation and expansion. However, there are no data on KGF expression in human autosomal dominant polycystic kidney disease (ADPKD) tissue, and it is unknown whether it affects ADPKD cyst-lining epithelial cell epithelial cell proliferation. METHODS: The expression and distribution of KGF and KGF receptor (KGFR) mRNA in ADPKD cystic and normal kidney tissues were examined using quantitative real-time polymerase chain reaction (PCR) and in situ hybridization. KGF and KGFR protein expression in the above tissues was analysed by immunohistochemistry and western blot. The effect of KGF on cyst-lining epithelial cell proliferation was assessed by MTT assay, and its effect on the cyst-lining epithelial cell cycle was analysed by flow cytometry. The effect of KGF on cyclin D1 and P21(wafl) gene expression in cyst-lining epithelial cells was also determined. RESULTS: KGF and KGFR mRNA expression in ADPKD cysts was higher than in normal kidney tissues. KGF and KGFR protein expression was also higher in ADPKD cysts and was localized to cyst-lining epithelial cells, tubular and interstitial cells. In vitro experiments revealed that KGF promoted cyst-lining epithelial cell proliferation, and decreased the ratio of G0/G1 phase but increased that of S phase. In response to KGF, the expression of the cyclin D1 gene in cyst-lining epithelial cells increased markedly while P21(wafl) expression decreased. CONCLUSIONS: KGF and KGFR expression was upregulated in ADPKD kidney tissues. KGF stimulated the proliferation of cyst-lining epithelial cell in vitro by regulating the expression of cyclin D1 and P21(wafl) genes. KGF may play a role in pathogenesis of ADPKD.     

Cyclic AMP promotes growth and secretion in human polycystic kidney epithelial cells

BACKGROUND: Progressive cyst enlargement, the hallmark of autosomal-dominant polycystic kidney disease (ADPKD) and autosomal-recessive (ARPKD) polycystic kidney disease, precedes the eventual decline of function in these conditions. The expansion of individual cysts in ADPKD is determined to a major extent by mural epithelial cell proliferation and transepithelial fluid secretion. This study determined if common receptor-mediated agonists and an anonymous lipid stimulate the production of 3' 5'-cyclic monophosphate (cAMP) in mural epithelial cells from the two major types of human cystic diseases. METHODS: cAMP responses to maximally effective concentrations of renal agonists were determined together with measurements of transepithelial anion current and cellular proliferation and extracellular signal-related kinase (ERK 1/2) expression in primary cultures of epithelial cells from human ADPKD and ARPKD cysts. RESULTS: The rank orders of responses to ligands for ADPKD and ARPKD cells were identical: epinephrine > desmopressin (DDAVP) approximately arginine vasopressin (AVP) > adenosine > prostaglandin E(2) (PGE(2)) > parathyroid hormone (PTH). cAMP concentrations elevated by epinephrine, DDAVP, adenosine, and PGE(2) were diminished by receptor-specific inhibitors. Pools of cyst fluid collected individually from 16 of 19 ADPKD kidneys increased, to varying degrees, cAMP levels in ADPKD and ARPKD cells. PGE(2), beta-adrenergic and AVP antagonists partially inhibited cAMP accumulation in response to fluids from three kidneys, but a large portion of the endogenous activity was attributed to yet-to-be identified bioactive lipid, designated cyst activating factor (CAF). CAF stimulated cAMP production in ADPKD and ARPKD cells, activated ERK(1/2), and increased cellular proliferation in ADPKD cells. CAF increased positive short circuit current (I(SC)) in polarized ADPKD and T-84 monolayers, indicating stimulation of net anion secretion. CONCLUSION: Endogenous adenylyl cyclase agonists promote cell proliferation and electrolyte secretion of human ADPKD and ARPKD cells in vitro. We suggest that increased levels of cAMP may accelerate cyst growth and overall renal enlargement in patients with PKD.     

Experimental therapy of prostate cancer with novel natural product anti-cancer ginsenosides

BACKGROUND: Ginseng and its components exert various biological effects, including antioxidant, anti-carcinogenic, anti-mutagenic, and anti-tumor activity, and recent research has focused on their value in human cancer prevention and treatment. We recently isolated 25-hydroxyprotopanaxadiol (25-OH-PPD) and 25-hydroxyprotopanaxatriol (25-OH-PPT) from Panax ginseng and evaluated their anti-cancer activity in vitro. METHODS: We compared the effects of the two compounds on human prostate cancer LNCaP and PC3 cells in vitro and in a mouse PC3 xenograft tumor model. We also accomplished a preliminary determination of the mechanisms of action of the compounds. RESULTS: 25-OH-PPD, but not 25-OH-PPT, inhibited prostate cancer cell growth and proliferation, induced apoptosis, and led to arrest in the G1 phase of the cell cycle. In nude mice bearing PC3 xenograft tumors, 25-OH-PPD inhibited tumor growth in a dose-dependent manner and could be safely combined with chemotherapeutic agents (taxotere and gemcitabine) and radiation therapy to improve the anti-tumor effects. Further, in both PC3 and LNCaP cell lines, 25-OH-PPD increased expression of p21, p27, and Bax, induced PARP cleavage and activated caspases. The compound also reduced expression of MDM2, E2F1, Bcl2, cdk2/4/6, and cyclin D1, which correlated with the cell cycle arrest in G1 and the decrease in proliferation. Moreover, 25-OH-PPD demonstrated low toxicity to non-cancer cells and no observable host toxicity in animals either alone or in combination with conventional therapies. CONCLUSIONS: The newly identified ginsenoside 25-OH-PPD may have potential as a novel prostate cancer therapeutic agent.     

Inhibition of proliferation of PC3 cells by the branched-chain fatty acid, 12-methyltetradecanoic acid,is associated with inhibition of 5-lipoxygenase

BACKGROUND: Branched-chain fatty acids or fatty alcohols have been reported to possess anti-tumor activity in various tumor models. Here we study 12-methyltetradecanoic acid (12-MTA), a branched-chain fatty acid, isolated from a sea cucumber extract, on the growth of prostate cancer cells and investigate the underlying mechanisms of its effect. METHODS: 12-MTA was evaluated by MTT assay for its ability to inhibit cell proliferation in various cancer types. The ability of 12-MTA to induce apoptosis of PC3 cells was examined by morphologic changes, propidium iodide (PI) staining, and caspase-3 activation. Furthermore, alteration of eicosanoid metabolism by 12-MTA was examined in PC3 and RBL-1 cells and in purified lipoxygenase (LOX) and cyclooxygenase (COX) enzymes. RESULTS: 12-MTA inhibited proliferation of various cell lines, with IC50s ranging from 17.99 to 35.44 microg/ml. PI staining clearly showed that 12-MTA caused PC3 cell death through induction of apoptosis. At 50 microg/ml, 12-MTA increased caspase-3 activity four to seven-fold compared with that in control cells. Examination of cellular arachidonate metabolism showed that at 25 microg/ml, 12-MTA reduced the level of 5-hydroxyeicosatetraenoic acid (5-HETE) by 45%. Furthermore, exogenous 5-HETE protects PC3 cells from 12-MTA induced cell death. CONCLUSIONS: 12-MTA inhibited proliferation of cancer cells via apoptosis, in which caspase-3 may play a role. At relevant concentrations, 12-MTA can selectively inhibit the formation of 5-HETE, a metabolite of 5-lipoxygenase. This agent may be a novel adjunctive therapy for selected malignancies including prostate cancer.     

Inhibitory effects of digitalis on the proliferation of androgen dependent and independent prostate cancer cells

PURPOSE: Digitalis or cardiac glycosides have been noted to induce tumor static or oncolytic effects in various types of cancer. We evaluated the effects and underlying mechanisms of cardiac glycosides, including digoxin, digitoxin and ouabain, on the proliferation of hormone dependent and independent prostate cancer cell lines. MATERIALS AND METHODS: Cell proliferation of the 3 human prostate cancer cell lines LNCaP, DU145 and PC3 was measured by 3-(4,5-dimethylthiazol-2-yle)2,5-diphenyltetralozium bromide (Sigma Chemical Co., St. Louis, Missouri) colorimetric assay. The cytotoxic effects of digitalis on prostate cancer cells were determined by lactate dehydrogenase measurements of the culture medium. Intracellular Ca2+ was measured by a dual wavelength spectrometer system. The percent of apoptotic cells after digitalis treatment was measured by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labeling and flow cytometry. RESULTS: Digoxin, digitoxin and ouabain significantly inhibited the proliferation of LNCaP, DU145 and PC3 cells at a dose of 1 or 10 microM. after 1 to 4 days of culture. Cytotoxicity of digitalis on the DU145 and LNCaP cells was dose dependent but cytotoxicity was not obvious in PC3. Digitalis (1 microM.) significantly increased intracellular Ca2+ in LNCaP and DU145 after 12 hours of culture but PC3 cells needed a 24-hour treatment to show any effect. In the apoptosis measurement digitalis at a dose of 1 and 10 microM. also significantly increased the percent of apoptotic cells in the LNCaP, DU145 and PC3 cell lines. Normal control human glomerular epithelial cells showed no response to digitalis treatment at all tested doses. CONCLUSIONS: Digitalis may inhibit the proliferation of prostate cancer cell lines, although the 3 cell lines showed varied sensitivity to digitalis. These effects are possibly the result of a mechanism involving sustained elevation of the concentration of intracellular Ca2+ and of apoptosis.     

环氧合酶2在胰腺癌中表达及其抑制剂对肿瘤生长的抑制作用

目的　研究胰腺癌组织中环氧合酶 2 (COX 2 )的表达及其与临床分期的关系 ;探讨选择性COX 2抑制剂对胰腺癌生长的体内外抑制作用。方法　分别应用免疫组织 (细胞 )化学染色、逆转录聚合酶链反应 (RT PCR)和Westernblot等研究胰腺癌组织和细胞株PC 3及PANC 1中COX 2表达。分析胰腺癌组织COX 2表达与临床TNM分期的关系。应用四唑氮蓝还原法 (MTT)研究选择性COX 2抑制剂Celebrex和NS 3 98对胰腺癌细胞生长的体外抑制作用。观察Celebrex对裸鼠移植瘤 (接种PC 3细胞 )生长的体内抑制作用。结果　COX 2免疫组织 (细胞 )化学染色结果显示 :2 4例胰腺癌组织阴性 3例 ,弱阳性 10例 ,强阳性 11例 ,阳性率 87 5% ;3例慢性胰腺炎组织 1例弱阳性 ,2例阴性 ;胰腺癌细胞株PC 3和PANC 1均为阳性。RT PCR结果显示两株胰腺癌细胞株和胰腺癌组织COX 2mRNA的表达较正常胰腺组织明显上调。Westernblot显示胰腺癌细胞株PC 3、PANC 1中COX 2蛋白表达阳性。胰腺癌组织COX 2表达程度与临床TNM分期呈正相关 (P <0 0 5)。NS3 98和Celebrex体外均呈剂量依赖性地抑制胰腺癌细胞株PC 3的增殖 ,以Celebrex的抑制作用较为显著。而Celebrex体内抑瘤率达 51 6%。结论　COX 2在胰腺癌中表达显著上调 ,其表达程度与胰腺癌临床TNM分期有关。     

维生素E琥珀酸酯诱导前列腺癌PC-3细胞凋亡的实验研究

目的：研究维生素E琥珀酸酯（VES）对非雄激素敏感的前列腺癌PC-3细胞株的凋亡诱导作用及分子机制。方法：以体外培养的PC-3细胞为研究对象,采用含不同浓度的VES培养液作用于细胞。采用噻唑兰（MTT）比色法检测细胞增殖活性;采用Wright—Giemsa染色、流式细胞术（FCM）检测细胞凋亡并测定Fas蛋白表达水平;采用酶联免疫法检测转化生长因子口（TGF-β）的表达水平的变化。结果：VES可显著抑制PC-3细胞的生长及增殖,光镜下可见到PC-3细胞呈典型凋亡的形态学改变。FCM细胞周期分析显示G2／M期细胞增加而s期细胞明显减少,Fas蛋白和TGF-β表达明显上调。结论：VES可诱导前列腺癌PC3细胞凋亡,其作用机制可能与其上调Fas、TGF-β的表达有关。