二甲双胍联合奥沙利铂抑制胃癌细胞SGC-7901的增殖和诱导凋亡

探讨体外培养的人胃癌细胞株SGC-7901经由二甲双胍与奥沙利铂联合处理后增殖和凋亡的响应及药物作用机制。采用CCK-8增殖检测法检测药物处理下对细胞的增殖影响并计算出两种药物的IC50值。采用RT-PCR、Western blotting以及流式细胞术检测药物作用下SGC-7901细胞周期相关和凋亡相关蛋白的mRNA水平、蛋白水平和凋亡水平。实验结果显示,二甲双胍和奥沙利铂单独作用都能够抑制SGC-7901细胞的增殖,联合用药组较单独用药组对细胞的抑制率更高。二甲双胍和奥沙利铂单独作用都能够抑制SGC-7901细胞cyclin D1的mRNA和蛋白水平,药物联用后,对细胞cyclin D1的抑制表达效果更明显。与对照组相比较,二甲双胍和奥沙利铂单独作用均能显著诱导SGC-7901细胞发生凋亡(p0.01),联合用药组亡率((50.13±10.75)%)明显高于单独用药的二甲双胍组((35.06±9.17)%)和奥沙利铂组((42.59±11.98)%)。二甲双胍和奥沙利铂单独都能够抑制SGC-7901细胞中抗凋亡蛋白Bcl-2的mRNA和蛋白表达水平,并增加促凋亡蛋白Bax以及凋亡执行caspase3的mRNA和蛋白表达水平,而联合用药组中这种调控效果更加显著。二甲双胍与奥沙利铂能够抑制胃癌细胞的增殖并诱导细胞发生凋亡,可能是通过促进Bax和caspase3的表达,抑制cyclin D1和Bcl-2表达来实现的。     

RNA干扰Ｃyclin D1基因表达对瘢痕疙瘩成纤维细胞增殖和G1期调控的影响

为研究siRNA干扰瘢痕疙瘩成纤维细胞cyclin D1基因表达,对瘢痕疙瘩成纤维细胞的增殖、细胞周期和G1期调控的影响,构建了靶向cyclin D1的siRNA表达质粒.利用LipofecmmineTM2000转染体外培养的瘢痕疙瘩成纤维细胞,应用荧光定量PCR、RT-PCR检测cyclin D1 mRNA的干扰效果,应用MTT法、流式细胞仪检测细胞增殖和细胞周期的变化,应用免疫组织化学染色检测成纤维细胞中cyclin D1、CDK4、P16、pRb蛋白表达的影响.主要结果如F:a.靶向cyclin D1的特异性siRNA序列可以高效地抑制成纤维细胞cyclin D1基因表达,对照组与实验组在mRNA水平其表达抑制率分别为63.68%和92.83%(P<0.01);b.可以显著抑制瘢痕疙瘩成纤维细胞的增殖,改变细胞周期分布,G0/G1期细胞比例显著高于各对照组(P<0.05),细胞分裂被阻滞;c.免疫组化染色发现,转染72 h后,过表达的cyclin D1、CDK4和pRb蛋白,在瘢痕疙瘩成纤维细胞中均出现了不同程度的表达下调,而低表达的P16则呈上调表现.由上述结果可见,构建的靶向cyclin D1的RNAi表达质粒,可有效地抑制瘢痕疙瘩成纤维细胞cyclin D1基因表达,通过改变Gl期相关周期蛋白的水平,影响G1/S期的进程,显著地抑制成纤维细胞的增殖.     

G6PD通过细胞周期蛋白D1/D2调控人黑色素瘤细胞周期的进程

葡萄糖-6-磷酸脱氢酶(G6PD)在人皮肤黑色素瘤A375细胞中处于高表达与高活性状态, 但G6PD在黑色素瘤发生发展过程中的作用及其具体机制尚不明确.本文在前期运用 siRNA方法构建G6PD敲减的黑色素瘤A375稳转细胞(A375-G6PDΔ)基础上,构建表达载体pBabe-puro-G6PDWT在A375-G6PDΔ细胞中过表达野生型的G6PD基因,从而构建G6PD表达恢复的稳转细胞(A375-G6PDΔ-G6PDWT).3株细胞A375-WT、A375-G6PDΔ和 A375-G6PDΔ-G6PDWT经G6PD酶活性测定、MTT测定、克隆形成实验、流式细胞仪分析细胞周期和Western 印迹检测.结果显示,A375-G6PDΔ-G6PDWT细胞的G6PD蛋白表达量 (0.847 ± 0.080)及其活性(0.394 ± 0.029)分别是A375-G6PDΔ的3.28倍(P＜0.01) 和7.34倍(P＜0.01),分别是A375-WT细胞的91-57%和2.12倍(P＜0.05).与A375-WT细 胞相比,A375-G6PDΔ细胞G0/G1期细胞数增加,S期细胞数减少,增殖指数PI降低了25-70%（P＜0.05）,细胞周期蛋白D1/D2、细胞周期蛋白E表达分别下降37.4%、54.3% (P＜0.01)和17.3%;而A375-G6PDΔ-G6PDWT细胞呈现G1/S期阻滞解除,细胞周期蛋白D1/D2蛋白分别恢复到A375-WT细胞的89.5%和87.6%,细胞周期蛋白E表达未见 恢复,呈现生长增殖和克隆形成率的恢复并接近于A375-WT细胞. 结果提示,G6PD通 过细胞周期蛋白D1/D2调控人皮肤黑色素瘤A375细胞G1期向S期转换的进程,这为黑色 素瘤发病机制的研究提供了新的思路.     

茅苍术提取物在肺癌A549细胞中的抗增殖作用机制

目的:研究茅苍术提取物对肺癌A549细胞的肿瘤增殖抑制效果及机制。方法:MTT比色法检测茅苍术提取物对A549细胞增殖的抑制效果;流式细胞术分析茅苍术提取物对肺癌A549细胞周期的影响;Western Blot检测茅苍术刺激前后细胞周期蛋白D1(cyclin D1)蛋白表达量变化。结果:茅苍术提取物能有效抑制肺癌A549细胞增殖,且抑制效果与茅苍术提取物浓度呈现依赖性,茅苍术提取物刺激48h后,抑制效果最佳,IC50约为77.12μg/ml;细胞周期分析显示:茅苍术提取物可将细胞周期阻滞在G0/G1期,50μg/ml茅苍术提取物刺激48h后,G1期上升至53.41%;cyclin D1蛋白含量因茅苍术作用而下调。结论:茅苍术提取物能通过有效抑制cyclin D1的表达,进而将细胞周期阻滞于G1期,最终实现其抗增殖作用机制。     

二甲双胍对人膀胱癌细胞能量代谢的调控作用分析

目的:检测二甲双胍对人膀胱肿瘤细胞能量代谢的作用及分子机制。方法:将膀胱肿瘤细胞分为4组,分别用终浓度为0、20、40、60 mmol/L的二甲双胍处理,比色法检测各组葡萄糖的消耗和乳酸的生成,用ATP检测试剂盒检测各组ATP水平,用JC-1膜电位检测试剂盒检测二甲双胍对膀胱肿瘤细胞膜电位的影响,通过real-time PCR检测己糖激酶2(HK2)和电压依赖性阴离子通道(VDAC)的mRNA表达水平,采用Western印迹检测每组中HK2、VDAC、磷酸化信号转导与转录激活因子3(p-STAT3)的蛋白表达水平变化。结果:在20 mmol/L二甲双胍下,膀胱肿瘤细胞葡萄糖消耗增加,乳酸产生受到抑制,ATP产生和细胞线粒体膜电位降低,HK2、VDAC和p-STAT3的表达降低。结论:二甲双胍可能通过抑制HK2、VDAC和p-STAT3的表达来阻断膀胱肿瘤的糖酵解和线粒体功能,这为研究二甲双胍对肿瘤的抑制作用机制奠定了理论和实验基础。     

桦木酸对人胃癌SGC-7901细胞增殖的影响*

目的:利用不同浓度的桦木酸对人胃癌SGC-7901细胞增殖的影响。方法:桦木酸设4个不同浓度(0、10、20、30 μg/ml),并采用常规化疗药物5-Fu处理作为阳性对照,以探究其对细胞增殖的影响。采用台盼蓝拒染法和吉姆萨染色法分别检测桦木酸对人胃癌SGC-7901细胞生长抑制率及克隆形成率;EdU法检测SGC-7901的细胞增殖;利用流式细胞术检测细胞周期, 应用qRT-PCR和Western blot分别检测细胞周期蛋白cyclin D1,cyclin B1的mRNA和蛋白表达水平。结果:不同浓度的桦木酸处理人胃癌SGC-7901细胞48 h后,其细胞生长抑制率显著升高(P＜0.05),克隆形成率和细胞增殖率均明显降低(P＜0.01),且呈剂量和时间依赖性;人胃癌SGC-7901细胞被阻滞在G1/G0期,细胞周期蛋白cyclin D1和cyclin B1的mRNA和蛋白表达量也随桦木酸浓度升高而显著降低(P＜0.01)。且与5-Fu对照组相比,桦木酸浓度为20 μg/ml和30 μg/ml时,细胞增殖能力明显降低,细胞周期被抑制,细胞周期蛋白表达量均明显降低(P ＜0.05)。结论:桦木酸通过下调cyclin B1和cyclin D1基因表达,将人胃癌SGC-7901细胞阻滞在G1/G0期,从而抑制细胞增殖。     

孕激素诱导的microRNA-1a抑制子宫内膜上皮细胞增殖

本文旨在研究孕激素诱导micro RNA-1a(mi R-1a)在子宫内膜上皮细胞(endometrial epithelial cells,EECs)的表达及其对EECs增殖的作用。用雌激素(E2组)或雌、孕激素联合(E2P4组)处理去卵巢小鼠,q PCR检测mi R-1a的成熟体mi R-1a-3p的表达;将mi R-1a-3p拟似剂或抑制剂注入各组小鼠的一侧子宫角,另一侧注入拟似剂或抑制剂对照,流式细胞术检测mi R-1a-3p对EECs细胞周期的影响;免疫组化检测mi R-1a-3p对细胞周期蛋白cyclin D2、cyclin E1和cyclin E2表达的影响。在体外实验,将分离培养的原代小鼠EECs分为两组,分别给予雌激素处理(E2组)和雌、孕激素联合处理(E2P4组),q PCR检测mi R-1a-3p的表达;再用mi R-1a-3p拟似剂作用于雌激素预处理细胞,对照组给予非特异性拟似剂,Ed U掺入实验检测细胞增殖活性。体内q PCR结果显示,E2P4组小鼠EECs mi R-1a-3p的表达量相比E2组明显增加(P0.05)。流式细胞术结果显示mi R-1a-3p拟似剂能够将E2处理细胞的细胞周期进程阻滞在G1/S期(P0.05);mi R-1a-3p抑制剂能够部分逆转P4对细胞周期进程的G1/S期阻滞(P0.05)。小鼠子宫组织免疫组化结果显示mi R-1a-3p拟似剂能较明显地抑制cyclin E1和cyclin E2蛋白的表达(P0.05),而对cyclin D2蛋白表达无影响(P0.05)。体外q PCR结果显示E2处理组和E2P4联合处理组细胞中都未检测到mi R-1a-3p表达,体外Ed U掺入实验表明外源性mi R-1a-3p拟似剂能够一定程度抑制雌激素促细胞增殖作用(P0.05)。以上结果表明,孕激素可通过诱导mi R-1a-3p表达引起细胞周期G1/S期阻滞,从而抑制EECs细胞增殖,这种抑制增殖作用与其抑制cyclin E1和cyclin E2蛋白表达有关。     

siRNA-cyclin D1对乳腺癌MCF-7细胞增殖的抑制作用

研究小干扰RNA(small interfering RNA,siRNA)对乳腺癌MCF-7细胞株cyclin D1表达的抑制及对细胞增殖的影响。化学合成针对cyclin D1基因的siRNA,转染MCF-7细胞株;分别应用荧光定量PCR和免疫印迹测定cyclin D1 mRNA和蛋白的表达,CCK-8测定细胞的增殖活性,流式细胞仪检测细胞周期,软琼脂培养检测细胞克隆形成能力。在实验中,10、50、100 nmol/L siRNA-cyclin D1分别使MCF-7细胞cyclin D1 mRNA表达降低了57．85%、63．22%和68．02%,蛋白表达降低了51．13%、62．09%、77．68%。转染siRNA-cyclin D1后,细胞增殖受到抑制,细胞周期阻滞于G1期,软琼脂克隆形成率降低。结果提示siRNA可以有效抑制MCF-7细胞株中cyclin D1的表达,使细胞周期阻滞于G1期,从而抑制细胞增殖。     

抗酶1基因转染对HeLa细胞增殖及细胞周期的抑制作用

研究抗酶(antizyme)1对人宫颈癌HeLa细胞增殖与细胞周期的影响,并分析抗酶1对细胞周期蛋白D1(cyclin D1)的表达影响.采用定点突变技术,将抗酶1的frameshift位点缺失,随后将突变基因重组至真核表达载体pEGFP-N1中,鉴定后转染HeLa细胞.通过MTT法检测细胞增殖变化,流式细胞术分析抗酶1对细胞周期的影响.RT-PCR和Western印迹检测抗酶1转染对细胞周期蛋白 D1基因表达的影响.酶切结果显示,抗酶1突变基因成功克隆至pEGFP-N1中.成功转染HeLa细胞后,检测结果显示,抗酶1能够减慢HeLa细胞增殖速度,并使细胞停滞于G₀/G₁期,细胞周期蛋白D1基因的表达同时受到抑制.实验说明,抗酶1基因能够抑制HeLa细胞增殖,通过降低细胞周期蛋白D1的表达阻滞细胞周期.     

miR-155 通过p53/p21 调控前列腺癌细胞周期

目的:探讨miR-155对前列腺癌细胞周期的影响及其分子机制。方法:通过转染anti-miR-155抑制前列腺癌DU145和PC-3细胞中miR-155水平后,采用流式细胞术观察细胞周期的变化,western blot和RT-PCR观察p53和p21蛋白及CDK2和cyclin蛋白和m RNA表达的变化。结果:与对照组相比,DU145和PC-3细胞转染anti-miR-155后,G2/M期细胞阻滞,S期细胞数比例显著增加(P0.05),p53和p21蛋白和m RNA表达水平显著增加(P0.01),CDK2和cyclin E蛋白和m RNA表达均显著降低(P0.01)。结论:miR-155可影响人前列腺癌细胞的周期,可能与其调节p53、p21及其下游的CDK2和cyclin E的表达相关。     

The anti-proliferative effect of metformin in triple-negative MDA-MB-231 breast cancer cells is highly dependent on glucose concentration: Implications for cancer therapy and prevention

Background

Metformin has been shown to have a strong anti-proliferative effect in many breast cancer cell lines, mainly due to the activation of the energy sensing kinase, AMP-activated protein kinase (AMPK). MDA-MB-231 cells are aggressive and invasive breast cancer cells that are known to be resistant to several anti-cancer agents as well as to the anti-proliferative effect of metformin. As metformin is a glucose lowering drug, we hypothesized that normoglycemia will sensitize MDA-MB-231 cells to the anti-proliferative effect of metformin.

Methods

MDA-MB-231 cells were treated with increasing metformin concentrations in hyperglycemic or normoglycemic conditions. The growth inhibitory effect of metformin was assessed by MTT assay. The expression of several proteins involved in cell proliferation was measured by Western blotting.

Results

In agreement with previous studies, treatment with metformin did not inhibit the growth of MDA-MB-231 cells cultured in hyperglycemic conditions. However, metformin significantly inhibited MDA-MB-231 growth when the cells were cultured in normoglycemic conditions. In addition, we show that metformin-treatment of MDA-MB-231 cells cultured in normoglycemic conditions and not in hyperglycemic conditions caused a striking activation of AMPK, and an AMPK-dependent inhibition of multiple molecular signaling pathways known to control protein synthesis and cell proliferation.

Conclusion

Our data show that normoglycemia sensitizes the triple negative MDA-MB-231 breast cancer cells to the anti-proliferative effect of metformin through an AMPK-dependent mechanism.

General significance

These findings suggest that tight normoglycemic control may enhance the anti-proliferative effect of metformin in diabetic cancer patients.     

Combined Treatment with Exendin-4 and Metformin Attenuates Prostate Cancer Growth

Introduction

Recently, the pleiotropic benefits of incretin-based therapy have been reported. We have previously reported that Exendin–4, a glucagon-like peptide–1 (GLP–1) receptor agonist, attenuates prostate cancer growth. Metformin is known for its anti-cancer effect. Here, we examined the anti-cancer effect of Exendin–4 and metformin using a prostate cancer model.

Methods

Prostate cancer cells were treated with Exendin–4 and/or metformin. Cell proliferation was quantified by growth curves and 5-bromo–2′-deoxyuridine (BrdU) assay. TUNEL assay and AMP-activated protein kinase (AMPK) phosphorylation were examined in LNCaP cells. For in vivo experiments, LNCaP cells were transplanted subcutaneously into the flank region of athymic mice, which were then treated with Exendin–4 and/or metformin. TUNEL assay and immunohistochemistry were performed on tumors.

Results

Exendin–4 and metformin additively decreased the growth curve, but not the migration, of prostate cancer cells. The BrdU assay revealed that both Exendin–4 and metformin significantly decreased prostate cancer cell proliferation. Furthermore, metformin, but not Exendin–4, activated AMPK and induced apoptosis in LNCaP cells. The anti-proliferative effect of metformin was abolished by inhibition or knock down of AMPK. In vivo, Exendin–4 and metformin significantly decreased tumor size, and further significant tumor size reduction was observed after combined treatment. Immunohistochemistry on tumors revealed that the P504S and Ki67 expression decreased by Exendin–4 and/or metformin, and that metformin increased phospho-AMPK expression and the apoptotic cell number.

Conclusion

These data suggest that Exendin–4 and metformin attenuated prostate cancer growth by inhibiting proliferation, and that metformin inhibited proliferation by inducing apoptosis. Combined treatment with Exendin–4 and metformin attenuated prostate cancer growth more than separate treatments.     

CDK4基因沉默对非小细胞肺癌A549 增殖和代谢的影响

目的:通过特异性小干扰RNA(small interfering RNA,si RNA),使CDK4基因沉默,探讨该基因沉默对肺癌A549细胞增殖和代谢的影响及其可能的作用机制。方法:将靶向CDK4小干扰RNA(si RNA-CDK4)和阴性对照干扰片段(si RNA-control)成功转染A549细胞后,利用实时荧光定量PCR和蛋白质免疫印迹法分别检测CDK4在m RNA和蛋白水平的变化;细胞计数法、CCK-8法和软琼脂糖克隆形成实验检测A549增殖的变化和克隆形成能力;FCM法检测A549细胞的细胞周期;18F-FDG摄取实验、乳酸检测试剂盒及海马技术检测A549细胞中葡萄糖、乳酸的量及氧耗的变化;利用RT-PCR检测CDK4基因沉默后A549细胞中糖代谢相关酶m RNA水平的变化。结果:将靶向CDK4小干扰RNA(si RNA-CDK4)转染A549细胞后,可明显抑制CDK4的m RNA和蛋白表达(P0.001,P0.01)。CDK4蛋白抑制后,细胞增殖在48、72和96 h均明显降低(P值均0.05),G1期细胞比例明显增多,S期细胞比例明显减少(P值均0.05);18F-FDG摄取量下降(42.21±1.90)%(P0.05),乳酸的生成量减少(29.39±5.35)%(P0.05),而细胞的基础耗氧量增加(67.17±3.58)%(P0.01);糖酵解相关酶PFKFB3、PKM2、LDHA在m RNA水平均明显减低(P0.001,P0.01,P0.001)。结论:抑制CDK4表达可明显降低糖酵解水平,并增加耗氧量;同时可引起细胞周期阻滞,抑制肿瘤细胞增殖。其机制可能与CDK4直接或间接调节糖酵解相关酶的表达有关。     

Bladder cancer cell viability inhibition and apoptosis induction by baicalein through targeting the expression of anti-apoptotic genes

The study was aimed to investigate the effect of baicalein, a flavonoid molecule isolated from the plant Oroxylum indicum on bladder cancer cell viability. The results revealed that baicalein treatment of T24 and 253J bladder cancer cells targeted the expression of mRNA and proteins corresponding to the anti-apoptotic genes. RT-PCR assay showed that anti-apoptotic genes were markedly over-expressed in the bladder cancer cells. Exposure of the bladder cancer cells to baicalein at 5 mg/mL doses for 72 h led to reduction in the expression of mRNA levels of antiapoptotic genes. In T24 cells, the levels of BCL2, Bcl-xL, XIAP and surviving was reduced by 65, 69, 58 and 72%, respectively. In T24 and 253J cells exposure to baicalein for 72 h resulted respectively in 39 and 46% reduction in cell viability. Baicalein treatment also induced apoptosis in the bladder cancer cells. In T24 and 253J cells baicalein treatment at 5 mg/mL for 72 h induced apoptosis in 79 and 86% cells respectively. Thus, baicalein mediated reduction in antiapoptotic gene expression inhibits viability and induces apoptosis in bladder cancer cells. Therefore, baicalein is of therapeutic importance for the development of bladder cancer treatment strategy.     

二甲双胍对人脐带间充质干细胞形态、增殖、表面标志及细胞周期的影响

目的探讨不同浓度二甲双胍（METF）对人脐带间充质干细胞（hUC-MSC）形态、增殖、表面标志及细胞周期的影响。 方法取健康足月新生儿脐带在体外分离出hUC-MSC进行传代培养,至第3代（流式细胞仪分析）对细胞进行鉴定,取第6代处于对数生长期的hUC-MSC （相对老化）,将对照组与不同浓度METF （0.1,1,5,10,20?mmol/L）干预的细胞进行比较,观察不同浓度METF干预对细胞的形态、增殖率（MTT法分别于24、48、72?h检测）、及细胞表面标志和细胞周期的影响,采用One-Way ANOVA,及LSD-t检验进行统计学分析。 结果（1）METF为0.1?mmol/L、1?mmol/L,细胞形态无显著改变,当药物浓度为5?~?20?mmol/?L时,随着药物浓度增加、培养时间延长,细胞形态改变越显著。（2）METF为0.1?mmol/L（24?h：101.28±0.98,24?h：104.06±1.76,24?h：101.51±0.67）促进hUC-MSC增殖,药物浓度为1?~ 10?mmol/L在培养初期可增加间充质干细胞的增殖率,随着培养时间的延长,细胞的增殖逐渐被抑制。METF为20?mmol/L（24?h：86.64±0.66,48?h：58.38±2.52,72?h：17.75±1.35）抑制细胞增殖,抑制作用随着时间延长而增强（P?< 0.05）。（3）当METF浓度为5,10,20?mmol/L时,随着药物浓度的增加,CD105的表达逐渐减弱（F?= 17.539,P?< 0.05）。METF未对CD44、CD90产生影响。（4）METF为0.1?mmol/L时降低G0/G1期的比例（64.16±1.20,P?< 0.05）,促进间充质干细胞的增殖,随着药物浓度的增加,细胞增殖逐渐被抑制。 结论METF浓度在0.1mmol/?L促进hUC-MSC增殖,而在浓度5 ~ 20?mmol/L时抑制人脐带间充质干细胞的增殖及表面标志CD105的表达,不同浓度的METF均未对CD44、CD90的表达产生影响。     

人参皂苷单体Rh2对人鼻咽癌CNE-2S细胞增殖及凋亡的影响

目的:探讨人参皂苷单体Rh2对人鼻咽癌CNE-2S细胞增殖及凋亡的影响。方法:将生长在对数期的人鼻咽癌CNE-2S细胞分为空白对照组、阴性对照组和实验组。对照组常规培养,阴性对照组采用含有DMSO的培养液培养,实验组在对照组细胞的基础上加入不同浓度人参皂苷单体Rh2处理。采用MTT法测定细胞增殖,PI单染流式细胞术分析各时期细胞所占百分比,Annexin V-PI双染流式细胞仪检测细胞的凋亡情况。结果:与阴性对照组相比,实验组各浓度下的Rh2对CNE-2S细胞均具有显著的增殖抑制作用(P0.05),且随着Rh2浓度的增加而呈现增强的趋势,其中浓度为12.5 mg·L-1 Rh2增值抑制率最低,浓度为100 mg·L-1Rh2增值抑制率最高。不同浓度人参皂苷单体Rh2 G0/G1期细胞分布显著高于阴性对照组(P0.001),且G2/M、S期细胞比例显著低于阴性对照组(P0.01),且随着人参皂苷单体Rh2浓度的增加作用呈现增强的趋势(P0.05);不同浓度的Rh2单体作用24h,CNE-2S细胞早期、晚期凋亡率及总凋亡率均较阴性对照组明显增高(P0.001),并且在Rh2单体浓度为100 mg·L-1时,凋亡率最高。结论:人参皂苷单体Rh2对人鼻咽癌CNE-2S细胞增殖及凋亡具有显著的影响,并且可能对单体Rh2的浓度存在依懒性。     

肿瘤微环境中ROS介导IgG表达对膀胱癌细胞增殖和侵袭能力的影响

摘要 目的：探讨肿瘤微环境（TME）中活性氧（ROS）介导免疫球蛋白G（IgG）表达对膀胱癌EJ细胞增殖、迁移和侵袭能力的影响。方法：临床收集的18例膀胱癌患者样本,通过Western blot法检测膀胱癌和癌旁正常组织样本中IgG表达量。利用免疫荧光染色（IF）技术分别对膀胱癌组织和癌旁正常组织中ROS和IgG分子进行共定位和相对定量分析。将活性氧清除剂N-乙酰基-L-半胱氨酸（NAC）加入膀胱癌细胞EJ中,实验分为3组：空白组（EJ细胞）、阴性对照组（EJ+PBS）、实验组（EJ+PBS+NAC）,10 mM NAC药物处理48小时后,运用DHE-ROS荧光探针技术和Western blot实验检测药物NAC对ROS和IgG相对表达水平的影响;通过克隆集落形成实验、划痕实验、Transwell实验检测去除ROS后对膀胱癌细胞增殖、迁移和侵袭的影响。结果：人体膀胱癌组织中ROS和IgG分子表达水平显著高于癌旁正常组织（P<0.001）;荧光显微镜显示膀胱肿瘤组织中正常膀胱尿路上皮细胞组织被肿瘤细胞严重破坏,结构紊乱不规则,IgG和ROS表达水平均升高,而癌旁组织膀胱尿路上皮组织的结构均匀规则;NAC药物处理EJ细胞后,与空白组和阴性对照组相比ROS和IgG表达显著降低,同时实验组细胞的增殖、迁移和侵袭能力明显下降（P<0.01）。结论：ROS和IgG在临床膀胱癌组织和体外膀胱癌细胞株EJ中均显著高表达,在肿瘤微环境中ROS通过调控IgG表达,从而促进膀胱癌细胞的增殖、迁移、侵袭。ROS和IgG可能成为膀胱癌早期诊断和生物治疗的临床新靶点。     

Inhibitory Role of the Small Leucine-Rich Proteoglycan Biglycan in Bladder Cancer

Background

Urothelial bladder cancer is the ninth most common cancer. Despite surgical and chemotherapeutic treatment the prognosis is still poor once bladder cancer progresses to a muscle-invasive state. Discovery of new diagnostic markers and pathophysiologic effectors might help to contribute to novel diagnostic and therapeutic options. The extracellular matrix microenvironment shaped by the extracellular matrix critically affects tumor cell and stroma cell functions. Therefore, aim of the present study was to assess the possible implication of the small leucine-rich proteoglycan biglycan in progression of human urothelial bladder cancer.

Methods and Results

For this purpose tumor biopsies of 76 bladder cancer patients with different tumor stages (pTa, pT1-T4) were investigated with respect to biglycan expression and correlated with a long-term (10 years) clinical follow-up. Interestingly, higher biglycan mRNA expression was associated with higher tumor stages and muscle invasiveness. In vitro knock-down of endogenous biglycan in human urothelial carcinoma cells (J82 cells) increased proliferation, whereas addition of recombinant biglycan and overexpression of biglycan inhibited tumor cell proliferation. In line with this growth-inhibitory effect of biglycan, transplantation of J82 cells after knock-down of biglycan resulted in significantly increased growth of subcutaneous xenograft tumors in nude mice in vivo. Furthermore, treatment with two anti-proliferative, multi-receptor tyrosine kinase inhibitors—sunitinib and sorafenib—strongly upregulated biglycan expression. Collectively, the experimental data suggest that high biglycan expression is associated with reduced tumor cell proliferation. In accordance, Kaplan-Meier analysis revealed higher 10-year survival in patients with high biglycan mRNA expression in tumor biopsies.

Conclusion

In conclusion, the present data suggest that biglycan is an endogenous inhibitor of bladder cancer cell proliferation that is upregulated in response to anti-proliferative tyrosine kinase inhibitors. In addition, high biglycan expression is associated with favorable prognosis.     

N—乙酰氨基葡萄糖转移酶Ⅲ,Ⅳ及Ⅴ在7721人肝癌细胞周期中的变化

In order to investigate the changes of N-acetylglucosaminyl transferase (GlcNAc-T) III, IV and V in cell cycle, the synchronization of 7721 human hepatocellular carcinoma cells was performed using serum hunger method. The percentages of cells in different phases during cell cycle were measured by flow cytometry (FCM) and the cell cycle was checked by determining the activity of cellular p34cdc2 kinase. It was found that the activities of GlcNAc-T III increased in G0/G1 cell peak phase and had correlation with the cell percentage of G0/G1 phase (r = 0.760, P < 0.05), while GlcNAc-T V showed the highest activity when G2/M cells were most abundant and had an apparent correlation with the cell percentage of G2/M phase (r = 0.868, P < 0.001). The changes of GlcNAc-T IV activity seemed not related to the cell cycle. The changes in opposite directions of relative activities (percentage of total GlcNAc-T III, IV, V) of GlcNAc-T III and GlcNAc-T V were observed during cell cycle (r = -0.951, P < 0.001), suggesting that these two enzymes might be regulated differently and functioned oppositely in the cells: GlcNAc-T V may be related to the proliferation of 7721 cells, while GlcNAc-T III may be related to the non-mitotic silence phase of the cells, or, it may be a factor against proliferation. Immunohistochemical results showed that the protein content of GlcNAc-T V was not significantly changed during cell cycle, and had no correlation with the activity of GlcNAc-T V, suggesting that the changes of GlcNAc-T V activity in cell cycle might not be resulted from the alteration of enzyme protein synthesis. The correlation between the activities of GlcNAc-T V and p34cdc2 kinase (r = 0.752, P < 0.05) was observed in cell cycle, implicating that GlcNAc-T V might possibly be regulated by p34cdc2 kinase.     

Erythropoietin enhancement of rat pancreatic tumor cell proliferation requires the activation of ERK and JNK signals

Erythropoietin (EPO) regulates the proliferation and differentiation of erythroid cells by binding to its specific transmembrane receptor EPOR. Recent studies, however, have shown that the EPOR is additionally present in various cancer cells and EPO induces the proliferation of these cells, suggesting a different function for EPO other than erythropoiesis. Therefore, the purpose of the present study was to examine EPOR expression and the role of EPO in the proliferation and signaling cascades involved in this process, using the rat pancreatic tumor cell line AR42J. Our results showed that AR42J cells expressed EPOR, and EPO significantly enhanced their proliferation. Cell cycle analysis of EPO-treated cells indicated an increased percentage of cells in the S phase, whereas cell numbers in G0/G1 phase were significantly reduced. Phosphorylation of extracellular regulatory kinase 1/2 (ERK1/2) and c-Jun NH₂ terminal kinase 1/2 (JNK1/2) was rapidly stimulated and sustained after EPO addition. Treatment of cells with mitogen-activated protein/ERK kinase (MEK) inhibitor PD98059 or JNK inhibitor SP600125 significantly inhibited EPO-enhanced proliferation and also increased the fraction of cells in G0/G1 phase. Furthermore, the inhibition of JNK using small interference RNA (siRNA) suppressed EPO-enhanced proliferation of AR42J cells. Taken together, our results indicate that AR42J cells express EPOR and that the activation of both ERK1/2 and JNK1/2 by EPO is essential in regulating proliferation and the cell cycle. Thus both appear to play a key role in EPO-enhanced proliferation and suggest that the presence of both is required for EPO-mediated proliferation of AR42J cells. erythropoietin receptor; cell signaling; mitogen-activated protein kinase induction