弗林蛋白酶抑制剂对乳腺癌MCF-7细胞生长和迁移的影响

目的 探讨乳腺癌转移的机制,为深入研究乳腺癌发生、发展机制提供理论基础.方法 应用不同浓度的弗林蛋白酶（Furin）抑制剂α1-PDX处理乳腺癌MCF-7细胞.用四甲基偶氮唑蓝（MTT）和克隆形成实验检测Furin抑制剂对MCF-7细胞增殖和克隆形成的影响.单层细胞迁移实验和Transwell实验检测MCF-7细胞迁移和浸润能力.Hoechst 33342/PI双染法检测细胞凋亡.酶联免疫吸附法检测细胞培养液中基质金属蛋白酶2（MMP-2）和MMP-9蛋白水平.Western blot检测细胞迁移相关蛋白MT1-MMP、血管内皮生长因子（VEGF）-C和VEGF-D水平.结果 不同浓度α1-PDX作用MCF-7细胞48 h以上时,细胞的生长受到抑制,集落形成降低,细胞凋亡率升高.但在低浓度情况下对细胞迁移和侵袭起抑制作用.α1-PDX降低了细胞内MT1-MMP、VEGF-C、VEGF-D的表达,同时细胞培养液上清中MMP-2和MMP-9浓度也低于对照组.结论 Furin抑制剂通过抑制乳腺癌MCF-7细胞MMP及VEGF表达抑制肿瘤的迁移能力.     

CD44基因变异体对人乳腺癌细胞株MCF-7的侵袭作用

目的 探讨一种新的CD44基因变异体(CD44v17)对人乳腺癌细胞株MCF-7侵袭能力的影响及其机制.方法 以人乳腺癌耐阿霉素细胞株(MCF-7/ADR)cDNA为模板,采用聚合酶链反应(PCR)扩增目的片段,将其T-A克隆后,进行测序;构建CD44v17质粒真核表达载体(pcDNA3.1-CD44v17);应用脂质体转染法将pcDNA3.1-CD44v17转染入MCF-7细胞中,采用逆转录聚合酶链反应(RT-PCR)及明胶酶谱法测定转染细胞基质金属蛋白酶(MMP)-2和MMP-9的表达;Transwell法检测CD44v17对MCF-7细胞的侵袭力;Western blot检测胞外信号调节蛋白激酶(ERK)及磷酸化蛋白激酶(p-ERK)变化.结果 限制性内切酶消化证实,重组载体已正确克隆;DNA序列分析显示,CD44v17包含CD44基因1～4号外显子、16～17号外显子、18号外显子1～205位碱基(GeneBank NO.FJ216964).MCF-7细胞转染peDNA3.1-CD44v17后,CD44 mRNA表达量和蛋白表达率分别为0.92±0.22和(70.0±2.5)%;透明质酸(HA)处理后,MMP-2 mRNA表达量和蛋白活性分别为0.72±0.22和1.14.4-0.12,MMP-9 mRNA表达量和蛋白活性分别为0.85±0.19和1.23±0.25,细胞侵袭能力明显增加,侵袭细胞数目为352±33个/视野,而CD44单抗可以阻断这种作用;CD44单抗和促分裂原活化蛋白激酶(MAPK)通路抑制剂预处理转染细胞后,显著阻断了P-ERK的表达.结论 在MCF-7/ADR细胞中发现CD44v17,并成功克隆和建立pcDNA3.1-CDd4v17;HA与CD44v17受体结合,通过CD44→ras→MAPK信号传导通路调节MMP-2和MMP-9的表达,从而增加MCF-7细胞的侵袭力.     

β-榄香烯注射液对人肝癌HepG-2细胞侵袭、迁移的作用及其相关机制

目的探讨β-榄香烯注射液对人肝癌HepG-2细胞侵袭、迁移的作用及其相关机制。方法首先进行肝癌HepG-2细胞培养,设置实验组及对照组。实验组细胞给予不同浓度(10、20、30、50、100、200、400μg/mL)的β-榄香烯注射液处理,对照组细胞不添加任何药物处理。以MTT法检测HepG-2细胞活力,另采用Transwell小室迁移/侵袭实验检测HepG-2细胞体外迁移能力及侵袭能力;采用细胞-基质粘附实验测定HepG-2细胞的粘附能力;最后以Western blot法定量检测HepG-2细胞MMP-2、MMP-9基因的表达。结果 MTT检测结果显示,当β-榄香烯注射液浓度为50、100、200及400μg/mL时,HepG-2细胞的活力随β-榄香烯注射液浓度的增大而明显降低(P<0.05),具有浓度依赖性;细胞-基质粘附实验结果显示,随着β-榄香烯注射液浓度的增大,HepG-2细胞的粘附率明显降低(P<0.05或P<0.01);Transwell迁移/侵袭实验结果显示,随着β-榄香烯注射液浓度的加大,HepG-2细胞侵袭及迁移数量逐步降低,且β-榄香烯注射液浓度为20、30μg/mL时HepG-2细胞迁移及侵袭细胞数量明显降低,而迁移及侵袭抑制率显著升高(P<0.05或P<0.01)。Western blot实验显示,随着β-榄香烯注射液浓度的加大,MMP-2及MMP-9蛋白表达量均逐渐降低,且对MMP-2蛋白表达的抑制作用更为显著。结论β-榄香烯注射液可有效降低肝癌HepG-2细胞的粘附能力,并抑制其侵袭及迁移,其作用机制很可能与其明显下调机体MMP-2及MMP-9蛋白表达相关。     

TAGLN基因过表达对乳腺癌细胞迁移和侵袭能力的影响

目的 研究TAGLN基因过表达对人乳腺癌细胞MDA-MB-231迁移能力和侵袭能力的影响及其分子机制.方法 对MDA-MB-231细胞采用慢病毒表达系统构建TAGLN基因稳定过表达细胞株,将MDA-MB-231细胞正常培养设为空白对照组,空载体慢病毒包装感染MDA-MB-231细胞后获得的稳定转染细胞株设为空载体对照组.Real time PCR和Western blot检测TAGLN mRNA和蛋白表达,划痕实验和Transwell侵袭实验检测细胞迁移和侵袭能力,Western blot检测TAGLN基因过表达后基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)和MMP-9蛋白表达变化.结果 MDA-MB-231细胞感染TAGLN基因过表达慢病毒载体后,细胞中TAGLN mRNA表达和蛋白表达升高(均P＜0.01),成功构建TAGLN基因过表达稳定细胞株(231-TAGLN).231-TAGLN细胞的体外迁移能力和侵袭能力下降,与空载体对照组和空白对照组细胞比较,差异均具有统计学意义(均P＜0.01),同时伴有MMP-2和MMP-9表达水平降低(均P＜0.01).结论 TAGLN基因过表达可以抑制乳腺癌细胞的迁移和侵袭,MMP-2和MMP-9基因表达下降可能参与这一过程.     

蛋白酪氨酸磷酸酶参与促发的细胞移动过程

 目的　探讨蛋白酪氨酸磷酸酶SHP-2在IL-1β所促发的细胞移动中的作用。方法　构建重组质粒SHP-2-GFP以及SHP-2C>S-GFP 并分别转入MCF-7乳腺癌细胞中，建立SHP-2-GFP- MCF-7和SHP-2C>S-MCF-7细胞株。采用荧光显微镜技术观察细胞移动情况；RT-PCR、免疫印迹法检测钙黏蛋白和金属蛋白酶的变化情况，确定蛋白磷酸酶SHP-2在细胞移动中的作用。结果　E-钙黏蛋白在IL-1β刺激的SHP-2转染的乳腺癌细胞株中的表达量是最低的，而金属蛋白酶MMP-9的表达量最高。结论　SHP-2参与IL-1β促发的细胞移动，并且通过减少E-钙黏蛋白的表达以及增强金属蛋白酶MMP-9的分泌来发挥作用的。     

乳腺癌MMP-2、MMP-9的体外阻断研究

目的:探讨乳腺癌MMP-2、MMP-9表达的临床病理联系及直接阻断MMP-2、MMP-9对乳腺癌细胞增殖、侵袭及细胞周期的影响。方法:应用免疫组织化学方法检测48例乳腺癌MMP-2、MMP-9的表达。明胶酶谱法检测乳腺癌MCF-7细胞MMP-2、MMP-9的表达。MCF-7细胞接种于预铺BME的Tran-swell小室上室,与MMP-2、MMP-9的阻断剂CTT共孵育16h,观察阻断MMP-2、MMP-9对MCF-7细胞侵袭能力的影响。MCF-7细胞与CTT共孵育12h后,MTT法检测阻断MMP-2、MMP-9对细胞增殖能力的影响。MCF-7细胞与CTT共孵育24h后,PI染色流式法检测阻断MMP-2、MMP-9对细胞凋亡和细胞周期的影响。结果:48例乳腺癌组织有MMP-2表达者45例(93.75%),MMP-9表达者38例(79.17%),MMP-2和MMP-9在发生淋巴结转移组明显高表达(P<0.05);组织学分级越高,MMP-2和MMP-9的表达越显著(P<0.05)。明胶酶谱法检测:在MCF-7培养上清中检测到MMP-2、MMP-9的表达。在浓度为100μg/ml和200μg/ml时CTT对MCF-7细胞的侵袭抑制率达到39.5%和61.9%。在终浓度为50、100、200μg/ml时,CTT对MCF-7细胞的增殖率均无明显下降(P>0.05)。CTT处理组MCF-7细胞经流式法检测未见凋亡峰,细胞周期各期未见明显阻滞(P>0.05)。结论:MMP-2、MMP-9与乳腺癌的淋巴结转移密切相关,阻断MMP-2、MMP-9可有效抑制乳腺癌的浸润和转移。     

乳腺癌MMP-2、MMP-9的体外阻断研究

目的:探讨乳腺癌MMP-2、MMP-9表达的临床病理联系及直接阻断MMP-2、MMP-9对乳腺癌细胞增殖、侵袭及细胞周期的影响。方法:应用免疫组织化学方法检测48例乳腺癌MMP-2、MMP-9的表达。明胶酶谱法检测乳腺癌MCF-7细胞MMP-2、MMP-9的表达。MCF-7细胞接种于预铺BME的Tran-swell小室上室,与MMP-2、MMP-9的阻断剂CTT共孵育16h,观察阻断MMP-2、MMP-9对MCF-7细胞侵袭能力的影响。MCF-7细胞与CTT共孵育12h后,MTT法检测阻断MMP-2、MMP-9对细胞增殖能力的影响。MCF-7细胞与CTT共孵育24h后,PI染色流式法检测阻断MMP-2、MMP-9对细胞凋亡和细胞周期的影响。结果:48例乳腺癌组织有MMP-2表达者45例(93.75%),MMP-9表达者38例(79.17%),MMP-2和MMP-9在发生淋巴结转移组明显高表达(P<0.05);组织学分级越高,MMP-2和MMP-9的表达越显著(P<0.05)。明胶酶谱法检测:在MCF-7培养上清中检测到MMP-2、MMP-9的表达。在浓度为100μg/ml和200μg/ml时CTT对MCF-7细胞的侵袭抑制率达到39.5%和61.9%。在终浓度为50、100、200μg/ml时,CTT对MCF-7细胞的增殖率均无明显下降(P>0.05)。CTT处理组MCF-7细胞经流式法检测未见凋亡峰,细胞周期各期未见明显阻滞(P>0.05)。结论:MMP-2、MMP-9与乳腺癌的淋巴结转移密切相关,阻断MMP-2、MMP-9可有效抑制乳腺癌的浸润和转移。     

LOX在乳腺癌中的表达及与MMP-2、MMP-9相关性的实验研究

目的 探讨赖氨酰氧化酶(LOX)在不同侵袭、转移潜能的乳腺癌细胞株的表达及LOX与MMP-2、MMP-9的关系.方法 以RT-PCR检测LOX mRNA在乳腺癌细胞株MDA-MB-231、MCF-7的表达水平.40只裸鼠随机分为2组,每组裸鼠的乳腺脂肪垫内分别接种上述不同的细胞,建立人乳腺癌原位移植瘤模型.6周后测定肿瘤体积,SP免疫组织化学法检测移植瘤中LOX、MMP-2、MMP-9的表达情况,并对数据进行统计学处理.结果 高侵袭、转移潜能的乳腺癌细胞后第6天均有肿瘤形成,至6周时MDA-MB-231组肿瘤体积为(758.84±241.08)mm3,MCF-7组为(210.36±101.06)mm3,差异有统计学意义(P＜0.01).LOX与MMP-2、MMP-9的表达呈正相关(P＜0.01).结论 乳腺癌细胞高侵袭、转移的潜能可能与LOX、MMP-2、MMP-9的高表达及其相互之间协同作用相关.     

膜型基质金属蛋白酶-1对乳腺癌细胞浸润能力的影响

目的 研究膜型基质金属蛋白酶-1（MT1-MMP）对乳腺癌细胞株浸润能力的影响,并初步探讨其作用机制。方法 用20μg／ml刀豆素（ConA）刺激乳腺癌细胞株MDA—MB-453,促使其表达MT1-MMP蛋白,并用免疫细胞化学和Western blot法检测;然后加入外源性MMP-2原酶（proMMP-2）,并用明胶酶谱分析法检测proMMP-2被激活的情况;最后用侵袭实验检测细胞株的浸润能力。实验中将细胞株分为4组：空白对照组、ConA组、MMP-2组和ConA＋MMP-2组,各组实验结果进行对比分析。结果 利用ConA刺激后,ConA组和ConA＋MMP-2组的细胞均表达MT1-MMP蛋白,另两组无MT1-MMP蛋白表达。明胶酶谱分析实验发现,MMP-2组只检测到72000原酶形式的MMP-2,ConA＋MMP．2组同时检测到72000原酶形式和64000活酶形式的MMP-2,其余两组检测不到任何形式MMP-2。侵袭实验结果显示,ConA＋MMP-2组细胞穿过Marigel胶的细胞数目明显多于其他组。结论 MT1-MMP能显著增强乳腺癌细胞株的浸润能力,其机制主要是通过激活MMP-2原酶,降解肿瘤周围的基质成分实现的。     

苯丁酸钠对甲状腺滤泡癌细胞侵袭能力及MMP-9和TIMP-1表达的影响

目的: 探讨苯丁酸钠(sodium phenylbutyrate,NaBP)对甲状腺滤泡癌细胞CGTHW-1的侵袭能力及基质金属蛋白酶-9(matrix metalloproteinase-9, MMP-9)和金属蛋白酶组织抑制剂-1(tissue inhibitor of metalloproteinase,TIMP-1)表达的影响 .方法:培养CGTHW-1细胞,通过Transwell侵袭实验观察苯丁酸钠对CGTHW-1细胞侵袭能力的影响,采用免疫细胞化学SP法及RT-PCR观察苯丁酸钠对CGTHW-1细胞中MMP-9和TIMP-1蛋白及mRNA表达的影响 .结果:4 mmol/L苯丁酸钠作72 h, CGTHW-1 细胞的侵袭细胞数显著减少[(29.8±1.77)vs(11.00±2.59),(P<0.01)].免疫细胞化学和RT-PCR 检测结果显示,4 、6 mmol/L 苯丁酸钠显著抑制CGTHW-1细胞中MMP-9、TIMP-1蛋白及mRNA的表达 (P<0.05). 结论:苯丁酸钠可通过下调MMP-9和TIMP-1的表达进而降低甲状腺滤泡癌CGTHW-1细胞的侵袭能力.     

他莫昔芬对乳腺癌MCF-7细胞侵袭能力的影响及其作用机制

目的 探讨他莫昔芬(TAM)对乳腺癌MCF-7细胞侵袭能力的影响及其作用机制.方法 采用对数生长期的乳腺癌MCF-7细胞,以无血清无酚红高糖DMEM培养基对其进行24 h的培养,然后将其分别接种并分为对照组(无血清无酚红高糖DMEM培养基)、TAM组(含有1μmol/L TAM的无血清无酚红高糖DMEM培养基),采用Western blot法、RT-PCR法检测两组MCF-7细胞基质金属蛋白酶-9(MMP-9)、MMP-2、血管内皮细胞生长因子(VEGF)蛋白及mRNA表达水平,采用Transwell法检测MCF-7细胞的侵袭能力.结果 TAM组MCF-7细胞中VEGF、MMP-9、MMP-2蛋白表达水平均明显高于对照组,VEGF、MMP-9、MMP-2 mRNA相对表达水平均明显高于对照组,差异均有统计学意义(P﹤0.01);TAM组MCF-7细胞的侵袭能力相对数明显高于对照组,差异有统计学意义(P﹤0.01).结论 TAM可能发挥类雌激素功能,促进乳腺癌MCF-7细胞侵袭能力,这与其提高MCF-7细胞中VEGF、MMP-9、MMP-2表达水平有关.     

Extraction-dependent effects of American ginseng (Panax quinquefolium) on human breast cancer cell proliferation and estrogen receptor activation

HYPOTHESIS: Ginseng root extracts and the biologically active ginsenosides have been shown to inhibit proliferation of human cancer cell lines, including breast cancer. However, there are conflicting data that suggest that ginseng extracts (GEs) may or may not have estrogenic action, which might be contraindicated in individuals with estrogen-dependent cancers. The current study was designed to address the hypothesis that the extraction method of American ginseng (Panax quinquefolium) root will dictate its ability to produce an estrogenic response using the estrogen receptor (ER)-positive MCF-7 human breast cancer cell model. METHODS: MCF-7 cells were treated with a wide concentration range of either methanol-(alc-GE) or water-extracted (w-GE) ginseng root for 6 days. Cells were grown in media containing either normal or charcoal-stripped fetal calf serum to limit exposure to exogenous estrogen. Thus, an increase in MCF-7 cell proliferation by GE indicated potential estrogenicity. This was confirmed by blocking GE-induced MCF-7 cell proliferation with ER antagonists ICI 182,780 (1 nM) and 4-hydroxytamoxifen (0.1 microM). Furthermore, the ability of GE to bind ERalpha or ERbeta and stimulate estrogen-responsive genes was examined. RESULTS: Alc-GE, but not w-GE, was able to increase MCF-7 cell proliferation at low concentrations (5-100 microg/mL) when cells were maintained under low-estrogen conditions. The stimulatory effect of alc-GE on MCF-7 cell proliferation was blocked by the ER antagonists ICI 182,780 or 4-hydroxyta-moxifen. At higher concentrations of GE, both extracts inhibited MCF-7 and ER-negative MDA-MB-231 cell proliferation regardless of media conditions. Binding assays demonstrated that alc-GE, but not w-GE, was able to bind ERalpha and ERbeta. Alc-GE (50 microg/mL) also induced an approximate 2.5-fold increase in expression of the estrogen-responsive pS2 gene, as well as progesterone receptor (PgR) gene expression, whereas w-GE was without effect. CONCLUSION: These data indicate that low concentrations of alc-GE, but not w-GE, elicit estrogenic effects, as evidenced by increased MCF-7 cell proliferation, in a manner antagonized by ER antagonists, interactions of alc-GE with estrogen receptors, and increased expression of estrogen-responsive genes by alc-GE. Thus, discrepant results between different laboratories may be due to the type of GE being analyzed for estrogenic activity.     

Inhibitory Effect of Ginseng on Breast Cancer Cell Line Growth Via Up-Regulation of Cyclin Dependent Kinase Inhibitor,p21 and p53

Objective: Breast cancer is global female health problem worldwide. Most of the currently used agents for breast cancer treatment have toxic side-effects. Ginseng root, an oriental medicine, has many health benefits and may exhibit direct anti-cancer properties. This study was performed to assess the effects of ginseng on breast cancer cell lines. Materials and Methods: Cytotoxicity of ginseng extract was measured by MTT assay after exposure of MDA-MB-231, MCF-10A and MCF-7 breast cancer cells to concentrations of 0.25, 0.5, 1, 1.5, 2 and 2.5 mg/well. Expression levels of p21WAF, p16INK4A, Bcl-2, Bax and P53 genes were analyzed by quantitative real time PCR. Results: The treatment resulted in inhibition of cell proliferation in a dose-and time-dependent manner. p53, p21WAF1and p16INK4A expression levels were up-regulated in ginseng treated MDA-MB-231 and MCF-7 cancer cells compared to untreated controls and in MCF-10A cells. The expression levels of Bcl2 in the MDA-MB-231 and MCF-7 cells were down-regulated. In contrast, that of Bax was significantly up-regulated. Conclusion: The results of this study revealed that ginseng may inhibit breast cancer cell growth by activation of the apoptotic pathway.     

Expression of Ets-related transcription factors and matrix metalloproteinase genes in human breast cancer cells

The expression levels of ets and MMP genes was examined in two breast cancer cell lines of differing invasive potential. The more invasive MDA-MB-231 cell line had higher levels of Ets-1, Ets-2, PEA3, ERM, Tel, Net, MMP-13 and -14 mRNA than MCF-7 cells. MMP-1, -3 and -16 mRNAs were expressed equally. TPA stimulated MMP-1, -9 and TIMP-1 mRNA expression in both cell lines. MMP-2 and MMP-7 mRNAs were not detected in either cell line. The Ets-1 protein was only detected in MDA-MB-231 cells and its level increased following TPA stimulation. TPA induced MMP-9 activity in MCF-7 cells and increased its activity in MDA-MB-231 cells, however, MMP-2 activity was not detected.     

紫花牡荆素抑制乳腺癌MCF-7细胞增殖与侵袭能力的研究

目的观察紫花牡荆素对乳腺癌MCF-7细胞株增殖与侵袭能力的影响并探讨其分子机制。方法应用四甲基偶氮唑蓝（MTT）比色法与侵袭实验检测紫花牡荆素对MCF-7细胞增殖与侵袭能力的影响,应用反转录PCR、Western blot法、Tunel法检测紫花牡荆素对基因表达、蛋白表达、细胞凋亡的影响。结果不同浓度紫花牡荆素均抑制MCF-7细胞增殖水平,同未加药对照组比较差异均有统计学意义（P〈0．05）,5、10、20μmol／L紫花牡荆素作用后,MCF-7细胞迁移数与未处理组相比分别降低20.3％、44．4％和50．3％（P〈0．05）。以10μmol／L紫花牡荆素处理后,凋亡细胞数增多,可以上调Bax与Caspase-3蛋白的表达水平,下调基质金属蛋白酶（MMP）-2与MMP-9的mRNA和蛋白表达水平。结论紫花牡荆素对于乳腺癌细胞恶性增殖与侵袭能力具有显著抑制作用。     

American ginseng (Panax quinquefolius L.) extract alters mitogen-activated protein kinase cell signaling and inhibits proliferation of MCF-7 cells

Ginseng has been shown to inhibit cancer cell proliferation and tumor growth, however the mechanisms underlying this inhibition have yet to be elucidated. An inhibitory effect of hot water-extracted American ginseng (Panax quinquefolius L.) root on cell proliferation was demonstrated using MCF-7 human breast cancer cells treated with a wide concentration range of the ginseng extract (GE) for 6 days. The effects of GE were concentration-dependent with an IC50 of 0.49 microg/microl and the minimum exposure time to elicit an inhibitory response was 24 hours. Using an antibody microarray, it was determined that several key cell survival proteins were altered in GE-treated cells, including several members of the mitogen-activated protein kinase (MAPK) family. A GE-induced decrease in phospho-MEK1/2 and -ERK1/2 and an increase in phospho-Raf-1 were observed and verified using Western blot analysis. Furthermore, mRNA and protein expression of the Raf-1 kinase inhibitor protein (RKIP) was shown to be transiently, yet significantly, upregulated following GE treatment. These results suggest that American ginseng may act to inhibit breast cancer cell proliferation by increasing the expression of RKIP, resulting in inhibition of the MAPK pathway. This novel mechanism has implications in the potential prevention and treatment of breast cancer.     

Histone deacetylases 1, 6 and 8 are critical for invasion in breast cancer

Histone deacetylases (HDACs) are associated with the development and progression of cancer, but it is not known which of the HDAC isoforms play important roles in breast cancer metastasis. This study identified the specific HDAC isoforms that are necessary for invasion and/or migration in human breast cancer cell lines. MDA-MB-231 cells were significantly more invasive and expressed higher levels of matrix metalloproteinase-9 (MMP-9) compared to MCF-7 cells. We compared the expression of HDAC isoforms between MCF-7 and MDA-MB-231 cells and found greater expression of HDAC4, 6 and 8 in MDA-MB-231 cells by RT-PCR and Western blot analyses. In addition, apicidin, a histone deacetylase inhibitor, was shown to attenuate the invasion, migration and MMP-9 expression in MDA-MB-231 cells. Using specific siRNAs directed against HDAC1, 4, 6 and 8, we show that inhibition of HDAC1, 6 and 8, but not HDAC4, are responsible for invasion and MMP-9 expression in MDA-MB-231 cells. We analyzed the invasiveness of MCF-7 cells overexpressing HDAC1, 4, 6 or 8 and found that overexpression of HDAC1, 6 or 8 increased invasion and MMP-9 expression. By developing HDAC isoforms as potential biomarkers for breast cancer metastasis, the present study can be extended to developing therapies for breast cancer invasion.     

Instructions for Authors

Tissue remodeling is a key element in the local invasion and metastasis of malignant breast tumors. The degradation of extracellular matrix that is associated with this process is thought to be mediated by a number of Zn²⁺-dependent matrix metalloproteinases (MMPs). In most cases these enzymes are not produced by the malignant epithelium itself but by adjacent breast stroma, suggesting an important role for cell-cell interactions. We have analyzed Gelatinase A (MMP-2) and Gelatinase B (MMP-9) gene expression in a panel of six breast cancer cell lines and six primary cultures of stromal cells deriving from breast cancer biopsies. With one exception we did not detect MMP-2 or MMP-9 gene expression in any of the established tumor cell lines. Conversely, tumor stroma-derived fibroblasts expressed MMP-2 mRNA, although no MMP-9 mRNA was seen in RNase protection assays. When fibroblasts were cultured in the presence of media conditioned by MCF-7 tumor cells, MMP-2 enzyme production increased but MMP-9 activity remained undetectable. However, when fibroblasts and MCF-7 tumor cells were co-cultured together, MMP-9 was induced. These observations were confirmed by immunocytochemical analysis of co-cultures of MCF-7 and tumor-derived fibroblasts in which MMP-2 and MMP-9 protein expression was confined to stromal cells adjacent to MCF-7 tumor cells. No MMP-2 or MMP-9 staining was detected in monocultures of the two respective cell types. We conclude that MMP-2 expression is present in the stroma of malignant tumors and is increased by paracrine stimulation mediated by soluble factors. In contrast, MMP-9 expression tumor-derived fibroblasts requires direct contact with malignant tumor epithelium.