乳腺癌浸润转移的研究进展

目的:乳腺癌是女性常见的恶性肿瘤之一,在西方国家其发病率和死亡率均居恶性肿瘤之首.近年来乳腺癌在我国发病率有上升的趋势,且其发病年龄有提早的趋向.乳腺癌的浸润和转移是导致病人死亡的关键所在,阻止乳腺癌的浸润、转移是现代乳腺癌治疗中的关键环节.因此,进一步研究乳腺癌细胞转移的分子基础,已成为提高乳腺癌治疗效果的热点问题.本文就乳腺癌浸润和转移的研究作一介绍.     

人乳腺癌细胞化疗敏感性与相关基因表达的关系

目的探讨人乳腺癌细胞化疗敏感性与多药耐药相关基因和凋亡调控基因表达的关系。方法MTT法检测5株人乳腺癌细胞株Bcap37、MCF-7、T47D、MDA-MB-231和MDA-MB-435对阿霉素(ADM)、顺铂(DDP)、丝裂霉素(MMC)、5-氟尿嘧啶(5-Fu)、卡氮芥(BCNU)的敏感性。流式细胞术检测多药耐药基因P-糖蛋白(P-GP)、谷胱甘肽-S-转移酶-π(GST-π)、肺耐药蛋白(LRP)、多药耐药相关蛋白(MRP)和甲基鸟嘌呤甲基转移酶(MGMT)等耐药相关基因和凋亡调控基因FAS、BCL-2、P53和P16的表达。结果不同人乳腺癌细胞株对同一药物敏感性差异较大。相关分析表明,细胞株对5-Fu的敏感性与P16表达呈正相关(P<0.01),对其余药物的敏感性与所检基因的表达水平无关。结论人乳腺癌细胞株对5-Fu的敏感性与P16表达有关。     

CTCF在乳腺癌中的表达及其对细胞增殖的影响

目的观察抑癌基因CTCF在乳腺癌细胞系、乳腺癌患者肿瘤组织及血清中的表达水平,并初步探讨其对乳腺癌细胞MCF7增殖的影响。方法 Western blot检测人乳腺癌细胞系MCF7、SKBR3和MDA-MB-231及正常乳腺细胞MCF-10A中CTCF蛋白的表达。实时荧光定量PCR和免疫组织化学法分别检测乳腺浸润性导管癌(n=23)、癌旁组织(n=10)及乳腺纤维腺瘤(n=10)中CTCF mRNA和蛋白水平的表达。酶联免疫吸附试验(ELISA)检测血清中CTCF的水平。进一步构建包装含CTCF的反转录病毒,感染MCF7细胞,筛选出稳定表达CTCF的细胞系,MTT法检测细胞的增殖。结果 CTCF在MCF-10A中表达最高,MCF7、SKBR3和MDA-MB-231中逐渐降低。乳腺癌组织中CTCF表达显著低于癌旁组织及乳腺纤维腺瘤组织(P0.01),CTCF在乳腺癌患者血清中表达量也显著低于健康对照(P0.01)。CTCF过表达能抑制MCF7细胞的增殖。结论 CTCF在乳腺癌细胞系、乳腺癌患者肿瘤组织及血清中表达降低。CTCF可抑制乳腺癌细胞的增殖。     

芪三酚与人乳腺癌MDC1基因关系的研究

目的探讨芪三酚（Res）对人乳腺癌MDA—MB-231细胞增殖抑制的相关效应及其与MDCl基因的关系。方法以人乳腺癌MDA—MB-231细胞株为研究对象,采用MTS方法测定细胞增殖,应用吖啶橙荧光染色观察Res对乳腺癌MDA—MB-231细胞的影响,用RT-PCR与免疫印迹方法测定MDCl基因与蛋白表达水平,用小RNA干扰MDCl基因后,用流式细胞仪检测细胞的凋亡并观察其对Res的敏感性影响。结果40μmol／L以上的Res可显著抑制乳腺癌MDA—MB-231细胞的增殖（P〈0．05）,给予0、60、120μmol／LRes能明显降低MDCl基因和蛋白的表达（P〈0．05）。用小RNA干扰MDC1基因后,流式细胞术分析显示,实验组（MDCl．siRNA）的细胞凋亡率[（45．13±6．2）％]较阴性对照组[（24．34±2．6）％]和未处理组[（17．69±4．9）％]明显上升（P〈0．05）,MTS结果显示MDCl基因干扰后细胞对Res的敏感性增加。结论40μmol／L以上的Res可以抑制MDA-MB-231细胞的增殖,Res可以有效降低MDC基因和蛋白的表达并促进细胞的凋亡。用小RNA干扰MDCl基因（MDCl-siRNA）后,MDA-MB-231细胞对Res的敏感性增加。     

Choline kinase overexpression increases invasiveness and drug resistance of human breast cancer cells

A direct correlation exists between increased choline kinase (Chk) expression, and the resulting increase of phosphocholine levels, and histological tumor grade. To better understand the function of Chk and choline phospholipid metabolism in breast cancer we have stably overexpressed one of the two isoforms of Chk‐α known to be upregulated in malignant cells, in non‐invasive MCF‐7 human breast cancer cells. Dynamic tracking of cell invasion and cell metabolism were studied with a magnetic resonance (MR) compatible cell perfusion assay. The MR based invasion assay demonstrated that MCF‐7 cells overexpressing Chk‐α (MCF‐7‐Chk) exhibited an increase of invasion relative to control MCF‐7 cells (0.84 vs 0.3). Proton MR spectroscopy studies showed significantly higher phosphocholine and elevated triglyceride signals in Chk overexpressing clones compared to control cells. A test of drug resistance in MCF‐7‐Chk cells revealed that these cells had an increased resistance to 5‐fluorouracil and higher expression of thymidylate synthase compared to control MCF‐7 cells. To further characterize increased drug resistance in these cells, we performed rhodamine‐123 efflux studies to evaluate drug efflux pumps. MCF‐7‐Chk cells effluxed twice as much rhodamine‐123 compared to MCF‐7 cells. Chk‐α overexpression resulted in MCF‐7 human breast cancer cells acquiring an increasingly aggressive phenotype, supporting the role of Chk‐α in mediating invasion and drug resistance, and the use of phosphocholine as a biomarker of aggressive breast cancers. Copyright © 2010 John Wiley & Sons, Ltd.     

syk真核表达载体的构建及其对人乳腺癌细胞MHC-I类分子表达的影响

目的：构建非受体蛋白酪氨酸激酶Syk的真核表达载体，转染人乳腺癌细胞，使其在细胞中稳定表达，以研究Syk对人乳腺癌细胞MHC—Ⅰ类分子表达的影响。方法：以RT-PCR法从人乳腺癌细胞株MDA-MB-468扩增出叼击编码序列基因片段，将其克隆到真核表达载体pcDNA3-1D／V5-His—TOPO中。对重组质粒进行酶切、PCR及测序鉴定后，以脂质体介导法转染Syk缺失的人乳腺癌细胞MDA-MB-231，经G418筛选，构建syk基因稳定表达的细胞株，通过Westernblot、RT-PCR和流式细胞术检测转染乳腺癌细胞Syk、MHC-Ⅰ及ICAMⅠ的表达。结果：构建了hsyk真核表达载体pcDNA3-1D／V5-His-TOPO／hsyk，并在人乳腺癌细胞MDA—MB-231中获得稳定表达。表达Syk的MDA—MB-231细胞同时可以高表达MHC-Ⅰ和ICAMⅠ。结论：成功地构建了syk真核表达载体并在真核细胞中表达，为进一步的肿瘤免疫研究奠定了实验基础。     

syk真核表达载体的构建及其对人乳腺癌细胞MHC-Ⅰ类分子表达的影响

目的:构建非受体蛋白酪氨酸激酶Syk的真核表达载体,转染人乳腺癌细胞,使其在细胞中稳定表达,以研究Syk对人乳腺癌细胞MHC-Ⅰ类分子表达的影响.方法:以RTPCR法从人乳腺癌细胞株MDA-MB-468扩增出syk编码序列基因片段,将其克隆到真核表达载体pcDNA3.1D/V5-His-TOPO中.对重组质粒进行酶切、PCR及测序鉴定后,以脂质体介导法转染Syk缺失的人乳腺癌细胞MDA-MB-231,经G418筛选,构建syk基因稳定表达的细胞株,通过Western blot、RT-PCR和流式细胞术检测转染乳腺癌细胞Syk、MHC-Ⅰ及ICAM-Ⅰ的表达.结果:构建了hsyk真核表达载体pcDNA3.1D/V5-His-TOPO/hsyk,并在人乳腺癌细胞MDA-MB-231中获得稳定表达.表达Syk的MDA-MB-231细胞同时可以高表达MHC-Ⅰ和ICAM-Ⅰ.结论:成功地构建了syk真核表达载体并在真核细胞中表达,为进一步的肿瘤免疫研究奠定了实验基础.     

syk基因真核表达载体的构建及其对乳腺癌细胞侵袭性抑制作用的体外研究

目的：构建非受体型蛋白酪氨酸激酶Syk的真核表达载体，转染人乳腺癌细胞，使其在乳腺癌细胞中稳定表达，为进一步探讨Syk抑制肿瘤细胞侵袭转移的具体机制奠定基础。方法：构建syk基因的真核表达载体pcDNA3．1D／V5．His-TOPO／syk，以脂质体介导法转染Syk表达缺失的MDA-MB-231细胞，经G418筛选，获得syk基因稳定表达的MDA-MB-231／syk细胞。通过流式细胞术和RT-PCR技术检测转染细胞MMP-9的表达变化，用体外迁移和侵袭力实验测定转染细胞的迁移和侵袭能力。结果：构建了syk基因的真核表达载体pcDNA3．1D／V5．His．TOPO／syk，并在MDA-MB-231细胞中获得稳定表达。与野生型MDA．MB-231细胞相比，MDA-MB-231／syk细胞表达MMP-9的水平明显降低（P〈0．01），并且该细胞的迁移和侵袭能力也明显降低（P〈0．01）。结论：候选抑癌基因syk通过脂质体可有效转染MDA-MB-231细胞，MDA-MB-231／syk细胞迁移和侵袭能力明显降低，这为进一步研究Syk在体内的抑瘤作用和乳腺癌基因治疗奠定了基础。     

下调血管内皮生长因子-C基因表达对乳腺癌MCF-7细胞侵袭抑制作用的研究

目的 探讨下调乳腺癌MCF-7细胞中血管内皮生长因子(VEGF)-C基因的表达后对乳腺癌细胞侵袭能力的影响.方法 脂质体介导重组质粒pSIREN-VEGF-C转染乳腺癌MCF-7细胞株.荧光定量PCR及Western印迹检测转染后对乳腺癌MCF-7细胞VEGF-C mRNA和蛋白质水平的影响.Transwell体外侵袭实验检测转染前后乳腺癌MCF-7细胞的侵袭能力.RT-PCR检测转染前后乳腺癌MCF-7细胞中MMP-2、-9 mRNA表达变化.结果 转染后获得稳定表达的细胞株.转染后的乳腺癌MCF-7细胞VEGF-C mRNA及蛋白表达均明显下调,抑制率分别为95%及100%(P<0.05).Transwell体外侵袭实验显示,转染后重组质粒组与阴性质粒相比,穿膜数明显减少(29.0±1.9比59.0±2.1,P<0.05).RT-PCR显示,转染后乳腺癌细胞的MMP-2、-9 mRNA表达均明显受抑制,抑制率分别为55%、75%(P<0.05).结论 下调VEGF-C表达对乳腺癌MCF-7细胞的侵袭能力有显著抑制作用.     

MicroRNA-140在乳腺癌细胞中对Nrf2及其下游抗氧化基因的表达调控

目的 本研究旨在揭示microRNA在乳腺癌细胞中对Nrf2表达的影响.方法 利用生物信息学方法预测miR-140与Nrf2的结合位点,然后采用双荧光报告系统检测miR-140对Nrf2 3′UTR及启动子上的8×ARE区域活性的影响;同时以实时荧光定量PCR法和Western bloting法检测过表达miR-140和加药刺激前后细胞中Nrf2及其下游基因的mRNA和蛋白的表达变化;最后,四甲基偶氮唑蓝(MTT)法检测转染miR-140后,对于不同浓度H2O2处理的细胞,观察其生长能力及对氧化应激敏感性的变化.结果 过表达miR-140能够显著抑制Nrf2 3′UTR区域的表达(P =0.007)和启动子上ARE区域的活性(P=0.01);在过表达miR-140的对照组和加药组细胞中,Nrf2及其下游基因mRNA和蛋白水平均被明显抑制(均P＜0.05);MTT实验结果显示转染miR-140细胞活力受到抑制,同时再使用不同浓度的H2 02刺激细胞后,细胞对氧化应激的敏感性增加(P＜0.01).结论 Nrf2可能作为miR-140的一个新型靶基因,miR-140能够通过抑制Nrf2,进而影响其下游一系列抗氧化基因的表达.     

Inactivation of the PTEN gene protein product is associated with the invasiveness and metastasis, but not angiogenesis, of breast cancer

PTEN is a novel tumor-suppressor gene located on chromosomal band 10q23. Loss of PTEN function has been implicated in the progression of several types of cancer, but the correlation between loss of PTEN expression and advanced carcinomas is not well established. The capacity for angiogenesis of a tumor is known to play a very important role in growth and metastasis, and there have been reports that PTEN relates to angiogenesis. In the present study, formalin-fixed and paraffin embedded tissues from 101 patients with breast carcinomas, including 88 cases of invasive ductal carcinomas and 13 cases of ductal carcinoma in situ (DCIS), were evaluated by immunohistochemical methods for the expression of PTEN and vascular endothelial growth factor (VEGF), as well as microvessel density (MVD). The results were compared with the clinicopathologic parameters. There was no loss of PTEN expression in any of the cases of DCIS, but 28 (32%) of the 88 invasive cases did not express PTEN. Loss of PTEN expression was associated with lymph node metastasis ( P  = 0.03), but did not correlate with tumor size, tumor grade, MVD or recurrence. VEGF expression significantly correlated with lymph node metastasis in invasive ductal carcinoma ( P  = 0.01). There was no correlation between the expression of PTEN and that of VEGF ( P  = 0.63). The present study suggests that loss of PTEN expression is common and correlates with tumor progression and lymph node metastasis in breast carcinoma. The relationship between loss of PTEN and progression of breast cancer may not be explained by modulation of angiogenesis.     

STC2 基因在乳腺癌中的表达及抑制其表达对癌细胞生物学特性的影响研究

目的:探讨斯钙素鄄2(STC2)基因在乳腺癌中的表达及抑制其表达对癌细胞增殖、周期及凋亡的影响。方法: RT鄄PCR 及Western blot 分别检测乳腺癌组织中STC2 基因的mRNA 及蛋白表达,并分析其与病理特征的关系;将STC2-siRNA 转染人乳腺癌MCF-7 细胞,另设空白对照组(Control)和阴性对照组(NC-siRNA),转染48 h 后,Western blot 检测各组细胞中 STC2、ki67、细胞周期素(cyclin D1)、活化的含半胱氨酸的天冬氨酸蛋白水解酶3(Cleaved caspase3)、Notch1、Hes1 蛋白表达; CCK8 检测细胞增殖;流式细胞仪检测细胞周期及凋亡。结果:STC2 基因在乳腺癌中的mRNA 及蛋白表达均显著高于癌旁组 织(P<0.05);STC2 基因表达与乳腺癌患者年龄、组织学分级及是否发生转移无关(P>0郾05),与病理分期、肿瘤大小相关(P< 0.05);NC-siRNA 组STC2 的蛋白表达与Control 组差异无统计学意义(P>0.05),STC2鄄siRNA 组STC2 的蛋白表达显著低于 Control 组(P<0.05);STC2鄄siRNA 组细胞存活率、S 期和G2/ M 细胞及ki67、cyclin D1、Notch1、Hes1 蛋白表达显著低于Control 组,细胞凋亡率、G0/ G1 期细胞及Cleaved caspase3 蛋白表达显著高于Control 组(P<0.05)。结论:STC2 基因在乳腺癌中高表 达,其表达与病理分期和肿瘤大小相关,抑制其表达可降低癌细胞的增殖,阻滞细胞于G1 期,并诱导细胞凋亡,其机制与下调 ki67、cyclin D1 和上调Cleaved caspase3 表达及下调Notch1 信号通路有关。     

Processed pseudogene from the von Hippel-Lindau disease gene is located on human chromosome 1.

The von Hippel-Lindau (VHL) disease gene is a tumor suppressor located at 3p25-26. While amplifying intron 1 of this gene, a smaller-than-expected product was found. This fragment was sequenced and was approximately 78% similar in sequence to the VHL gene and completely lacked sequence from the intron. No stop codons were found in the sequenced region. Using this DNA fragment as a probe for Northern blot hybridization analysis, no evidence was found for expression of a unique RNA. Because of the lack of intron 1 sequence and the likely lack of expression, the new sequence is most probably a part of a VHL processed pseudogene. The putative pseudogene was mapped to human chromosome band 1q12 using the polymerase chain reaction with template DNA from human/rodent somatic cell hybrids, a radiation hybrid panel, and a set of primers that were chosen to be maximally divergent from the genuine VHL gene. The human/rodent somatic cell hybrid DNAs were then used on Southern blots to determine which human bands are from the pseudogene and which are from the functional gene. This knowledge is valuable in interpreting Southern blot evidence of VHL gene abnormalities.     

乳腺癌中胎盘型谷胱甘肽S－转移酶基因的扩增与异常表达

在国内首次制备并用光敏生物素方法标记胎盘型谷胱甘肽Ｓ－转移酶（ＧＳＴ－π）ｃＤＮＡ探针，应用斑点杂交技术检测２４例乳腺癌ＧＳＴ－π基因ＤＮＡ扩增与ｍＲＮＡ异常表达。结果发现，２４例乳腺癌中，３例（１２．５％）存在ＤＮＡ扩增，７例（２９．２％）存在ｍＲＮＡ异常表达，ＤＮＡ扩增和ｍＲＮＡ表达之间存在正相关性，二者均与患者年龄、肿瘤大小、淋巴结转移无明显相关，但ｍＲＮＡ异常表达与乳腺癌ＥＲ表达呈现负相关性。结果证实人乳腺癌中既存在ＧＳＴ－π基因ＤＮＡ扩增，又存在ｍＲＮＡ异常表达，提示ＧＳＴ－π与乳腺癌有密切关系。     

截短型人bid基因的克隆、表达和促凋亡作用的研究

目的 :探讨截短型bid(truncatedbid ,tbid)基因的表达对Hela细胞的促进凋亡活性。方法 :用RT PCR法克隆人全长bid基因 ,测序正确后 ,通过PCR截去编码N末端 6 0个氨基酸残基的基因 ,而获得tbid基因。将其克隆入含绿色荧光蛋白(GFP)基因的真核表达载体pIRES2 EGFP中 ,用脂质体法转染Hela细胞。通过荧光显微镜、电子显微镜观察和TUNEL检测法 ,检测目的基因的表达对转染细胞的形态及生长状况的影响。结果 :成功地构建了tbid基因的真核表达载体。以其转染Hela细胞后 ,tbid基因在细胞中得到表达 ,随后引起细胞荧光强度下降 ,生长状况不良甚至死亡。电镜观察及TUNEL检测的结果显示 ,许多细胞呈典型的凋亡特征。结论 :tbid基因的表达可促进Hela细胞的凋亡