Metabolic reprogramming in triple-negative breast cancer

Since triple-negative breast cancer(TNBC)was first defined over a decade ago,increasing studies have focused on its genetic and molecular characteristics.Patients diagnosed with TNBC,compared to those diagnosed with other breast cancer subtypes,have relatively poor outcomes due to high tumor aggressiveness and lack of targeted treatment.Metabolic reprogramming,an emerging hallmark of cancer,is hijacked by TNBC to fulfill bioenergetic and biosynthetic demands;maintain the redox balance;and further promote oncogenic signaling,cell proliferation,and metastasis.Understanding the mechanisms of metabolic remodeling may guide the design of metabolic strategies for the effective intervention of TNBC.Here,we review the metabolic reprogramming of glycolysis,oxidative phosphorylation,amino acid metabolism,lipid metabolism,and other branched pathways in TNBC and explore opportunities for new biomarkers,imaging modalities,and metabolically targeted therapies.

GD2+ cancer stem cells in triple-negative breast cancer:mechanisms of resistance to breast cancer therapies

Research has led to the development of tailored treatment options for different cancers in different patients.Despite some treatments being able to provide remarkable responses,nearly all current treatments encounter the same issue:resistance.Here,we discuss our experiences with how breast cancers resist therapies.The focus of our discussion revolves around the cancer stem cell subpopulation and their mechanisms for resistance.

Discovery of a tetrahydroisoquinoline-based CDK9-cyclin T1 proteineprotein interaction inhibitor as an anti-proliferative and anti-migration agent against triple-negative breast cancer cells

Triple-negative breast cancer(TNBC)is a highly aggressive and metastasizing cancer that has the worst prognosis out of all breast cancer subtypes.The epithelial emesenchymal transition(EMT)and cancer stem cells(CSCs)have been proposed as important mechanisms underlying TNBC metastasis.CDK9 is highly expressed in breast cancer,including TNBC,where it promotes EMT and induces cancer cell stemness.In this study,we have identified a tetrahydroisoquinoline derivative(compound 1)as a potent and selective CDK9-cyclin T1 inhibitor via virtual screening.Interestingly,by targeting the ATP binding site,compound 1 not only inhibited CDK9 activity but also disrupted the CDK9-cyclin T1 proteineprotein interaction(PPI).Mechanistically,compound 1 reversed EMT and reduced the ratio of CSCs by blocking the CDK9-cyclin T1 interaction,leading to reduced TNBC cell proliferation and migration.To date,compound 1 is the first reported tetrahydroisoquinoline-based CDK9-cyclin T1 ATP-competitive inhibitor that also interferes with the interaction between CDK9 and cyclin T1.Compound 1 may serve as a promising scaffold for developing more selective and potent anti-TNBC agents.Our work also provides insight into the role of the CDK9-cyclin T1 PPI on EMT and CSCs and highlights the feasibility and significance of targeting CDK9 for the treatment of TNBC.

Breast cancer development and progression:Risk factors,cancer stem cells,signaling pathways,genomics,and molecular pathogenesis

As the most commonly occurring cancer in women worldwide,breast cancer poses a formidable public health challenge on a global scale.Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast.While the risk factors associated with this cancer varies with respect to other cancers,genetic predisposition,most notably mutations in BRCA1 or BRCA2 gene,is an important causative factor for this malignancy.Breast cancers can begin in different areas of the breast,such as the ducts,the lobules,or the tissue in between.Within the large group of diverse breast carcinomas,there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites.It is important to distinguish between the various subtypes because they have different prognoses and treatment implications.As there are remarkable parallels between normal development and breast cancer progression at the molecular level,it has been postulated that breast cancer may be derived from mammary cancer stem cells.Normal breast development and mammary stem cells are regulated by several signaling pathways,such as estrogen receptors(ERs),HER2,and Wnt/b-catenin signaling pathways,which control stem cell proliferation,cell death,cell differentiation,and cell motility.Furthermore,emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer,especially for triple-negative breast cancer.This review provides a comprehensive survey of the molecular,cellular and genetic aspects of breast cancer.

Breast cancer development and progression: Risk factors, cancer stem cells, signaling pathways, genomics, and molecular pathogenesis

As the most commonly occurring cancer in women worldwide,breast cancer poses a formidable public health challenge on a global scale.Breast cancer consists of a group of biologically and molecularly heterogeneous diseases originated from the breast.While the risk factors associated with this cancer varies with respect to other cancers,genetic predisposition,most notably mutations in BRCA1 or BRCA2 gene,is an important causative factor for this malignancy.Breast cancers can begin in different areas of the breast,such as the ducts,the lobules,or the tissue in between.Within the large group of diverse breast carcinomas,there are various denoted types of breast cancer based on their invasiveness relative to the primary tumor sites.It is important to distinguish between the various subtypes because they have different prognoses and treatment implications.As there are remarkable parallels between normal development and breast cancer progression at the molecular level,it has been postulated that breast cancer may be derived from mammary cancer stem cells.Normal breast development and mammary stem cells are regulated by several signaling pathways,such as estrogen receptors(ERs),HER2,and Wnt/b-catenin signaling pathways,which control stem cell proliferation,cell death,cell differentiation,and cell motility.Furthermore,emerging evidence indicates that epigenetic regulations and noncoding RNAs may play important roles in breast cancer development and may contribute to the heterogeneity and metastatic aspects of breast cancer,especially for triple-negative breast cancer.This review provides a comprehensive survey of the molecular,cellular and genetic aspects of breast cancer.

肿瘤微环境对乳腺癌干细胞样微球体培养鉴定的影响

目的:探讨肿瘤微环境在乳腺癌干细胞(breast cancer stem cells,BCSCs)培养鉴定及分化过程中的影响及意义。方法:采用无血清培养液PCM-2及成纤维细胞上清液对乳腺癌细胞及MCF-7细胞进行原代培养。观察乳腺癌细胞微球体形成状况,MTT比色法检测乳腺癌细胞的增殖能力,免疫细胞化学方法检测乳腺癌干细胞标记物及上皮间质标记物的表达,并通过RT-PCR进行验证。结果:无血清培养液PCM-2培养的原代细胞微球体的直径大于成纤维细胞上清液的培养(t=4.996,P=0.002),且原代细胞中ALDH1(aldehyde dehydrogenase 1)的表达率高于后者。成纤维细胞上清液培养的细胞生长速度较无血清培养液PCM-2快,差异具有统计学意义(P=0.004)。RT-PCR检测发现无血清培养液PCM-2培养的原代细胞中ALDH1表达上调,E-cadherin、Vimentin表达下调。结论:在乳腺癌原代细胞和MCF-7细胞中可以采用无血清悬浮培养方法富集BCSCs样微球体,成纤维细胞上清液能够促进BCSCs样微球体的增殖与分化。提示乳腺肿瘤微环境在乳腺癌细胞的生长增殖过程中发挥了至关重要的作用。

扶正消瘤方对人乳腺癌MCF-7干细胞体外增殖及凋亡的影响

目的:观察扶正消瘤方含药血清对人乳腺癌MCF-7干细胞增殖及凋亡的影响。方法:采用体外悬浮培养乳腺癌MCF-7干细胞作为研究对象,中药灌胃方法制备大鼠含药血清;实验设计为空白对照组,无药血清模型组、中药等效量组、中药1倍量组、中药2倍量组共5组;噻唑蓝(MTT)比色法检测细胞增殖情况,荧光免疫细胞化学法检测细胞凋亡情况。结果:中药含药血清等效剂量组、中药1倍剂量组和中药2倍剂量组对人乳腺癌MCF-7干细胞的抑制率均明显高于空白对照组和无药血清组(P<0.05);与空白对照组及无药血清组比较,扶正消瘤方含药血清组人乳腺癌MCF-7干细胞凋亡明显增多。结论:扶正消瘤方能明显抑制人乳腺癌MCF-7细胞的增殖,诱导其细胞凋亡。

尼美舒利对三阴性乳腺癌干细胞体外增殖和凋亡的影响

目的体外研究选择性环氧化酶-2(COX-2)抑制剂尼美舒利对三阴性乳腺癌(TNBC)干细胞体外增殖和凋亡的影响及可能的作用机制。方法在人乳腺癌细胞株MDA-MB-231中分别加入不同浓度的尼美舒利,作用24、48、72 h后,应用噻唑蓝比色法检测细胞增殖抑制作用,流式细胞仪检测细胞周期和凋亡,电镜观察细胞形态,Western blot法检测Cox/Bax/Bcl-2蛋白表达。结果尼美舒利能显著抑制TNBC干细胞增殖,呈时间和浓度依赖性;并使G0/G1期细胞增多,S期和G2/M期细胞减少,引起明显的细胞凋亡。电镜可见典型的细胞凋亡形态学特征:细胞体积缩小、细胞核固缩、凋亡小体形成等。凋亡比例呈剂量依赖。Western blot分析显示,尼美舒利作用细胞后,随着浓度的增加细胞COX-2和Bcl-2表达水平降低,但Bax表达水平增高。结论尼美舒利体外能够显著抑制TNBC干细胞增殖,诱导其凋亡,COX-2、Bcl-2及Bax等凋亡相关基因可能参与了尼美舒利诱导的TNBC干细胞凋亡过程。

MEK／ERK信号通路活性表达与乳腺癌干细胞增殖和凋亡的关系

目的探讨MEK／ERK信号通路在乳腺癌干细胞增殖和凋亡中的作用。方法体外培养乳腺癌干细胞，采用MEK抑制剂PD98059抑制MEK／ERK信号通路表达，Western blot检测PD98059对p—ERK1／2表达的影响，进一步应用MTT法测定PD98059对乳腺癌干细胞增殖的抑制作用，流式细胞术检测细胞周期变化；同时，TUNEL荧光染色分析、Histone／DNAELISA和流式细胞术检测评价细胞凋亡。结果PD98059可有效下调p—ERK1／2表达，抑制乳腺癌干细胞生长，诱导G0／G1期抑制；TUNEL荧光染色，Histone／DNAELISA检测和流式细胞术检测分析显示PD98059可有效诱导乳腺癌干细胞凋亡。结论MEK／ERK信号通路在乳腺癌干细胞增殖和凋亡中发挥重要作用。

丁酸盐二甲双胍对乳腺癌干细胞的抗肿瘤活性及细胞毒性作用研究

目的探讨丁酸盐二甲双胍对乳腺癌干细胞抗肿瘤活性及细胞毒性作用。方法利用超低粘附悬浮培养法,从MDA-MB-231细胞中,获得乳腺癌干细胞样细胞。随机将其分为对照组(化疗药物)和观察组(丁酸盐二甲双胍联合化疗药物),在缺氧状态下分别处理细胞,通过流式细胞仪,检测两组细胞凋亡情况,利用四甲基偶氮唑盐(MTT)法检测乳腺癌干细胞增殖活性。结果对照组丁酸盐二甲双胍能够促进MDA-MB-231细胞凋亡,对ER阳性的MCF-7无明显影响;观察组丁酸盐二甲双胍能够明显增加乳腺癌干细胞对化疗药物的敏感性。结论丁酸盐二甲双胍可促进乳腺癌干细胞凋亡,增强乳腺癌干细胞对化疗药物的敏感性。

二甲双胍对人类表皮生长因子受体-2阳性乳腺癌干细胞自我更新能力的干预

目的以曲妥珠单抗（TRA）为对照，观察二甲双胍（MET）对人类表皮生长因子受体（Her-2）阳性乳腺癌干细胞（BCSCs—HP）自我更新能力的影响。方法（1）以乙醛脱氢酶1（ALDH1）为标记，通过悬浮培养富集ALDH1阳性乳腺癌肿瘤干细胞（SC细胞）；（2）采用微球体形成试验、细胞计数试剂盒（CCK-8）法、Transwell侵袭试验研究二甲双胍对BCSCs．HP生物学行为及其自我更新能力的影响作用；（3）采用Westernblot方法检测分别应用TRA、MET及TRA＋MET干预BCSCs—HP（SC—TRA组，SC—MET组以及SC—MET—TRA组）后p21及哺乳动物雷帕霉素靶蛋白（mTOR）蛋白表达的变化。结果SC—TRA、SC—MET、SC．MET—TRA组的干细胞比例分别为（29．17±2．06）％、（14．08±1．18）％，（8．12±0．42）％，微球体形成率分别为（17．85±1．87）％、（11．08±0．94）％、（6．57±0．52）％，同时干细胞的增殖与侵袭能力均降低，p21及mTOR蛋白表达明显下降，差异有统计学意义（P〈0．05）。结论二甲双胍可以影响干细胞微球体的形成，抑制其体外增殖、侵袭及下调p21和mTOR蛋白的表达，抑制干细胞的自我更新能力。

乳腺癌干细胞分选与鉴定方法研究进展

乳腺癌是女性最常见恶性肿瘤,病死率居女性恶性肿瘤前列。乳腺癌干细胞的提出与研究的深入为乳腺癌的治疗提供了新思路和方法。富集纯化得到高纯乳腺癌干细胞是相关研究的基础与前提。本文就近年来乳腺癌干细胞分选与鉴定方法的研究进展作一综述。

人乳腺癌干细胞中CCR5的表达及意义

目的:探讨人乳腺癌干细胞和乳腺癌细胞中CCR5的表达及意义。方法:采用流式分选技术从人乳腺癌细胞系MCF-7中分选出乳腺癌干细胞,并利用SYBR实时PCR技术测定不同亚群乳腺癌细胞中CCR5的表达。结果:熔解曲线分析和琼脂糖凝胶电泳结果证实PCR反应的特异性;相对定量结果显示,乳腺癌干细胞CD44+CD24-/low的CCR5表达水平为对照组CD44+CD24+乳腺癌细胞的6.14倍(P<0.05)。结论:高表达CCR5的乳腺癌干细胞与乳腺癌细胞相比具有更强的侵袭转移能力,可能是乳腺癌转移关键因素之一。