无血清培养基分离肿瘤干细胞的研究进展

肿瘤干细胞(cancer stem cells,CSCs)被认为是肿瘤形成、生长、转移以及复发的根本原因。CSCs的分离、鉴定为CSCs的研究及靶向CSCs疗法的开发奠定了基础。目前,无血清培养法已经是分离培养CSCs的常用方法。本文对无血清培养基(serum free medium,SFM)分离CSCs的研究进展作一综述。     

肠道病毒71型在Cellspin系统中无血清微载体培养工艺的建立

目的建立肠道病毒71型(Enterovirus71,EV71)在Cellspin系统中无血清微载体培养工艺,为生物反应器培养EV71工艺的建立奠定基础。方法在Cellspin培养系统中对Vero细胞进行微载体培养,考察不同种类培养基MEM、DMEM/F12、VP-SFM、Opti-SFM、Opti-pro、MD505-199及不同微载体浓度3、5、10 g/L对细胞密度的影响。分别以MOI为0.2及2.0接种EV71至Vero细胞,考察病毒接种量对病毒增殖的影响。分别按培养上清、微载体洗脱液模式收毒,比较不同组分中EV71的抗原含量及TCID50。结果采用5 g/L微载体、VP-SFM培养基时,Vero细胞的密度达4.40×106个/ml;按MOI为2.0染毒,72 h后即可收毒,较MOI为0.2的收毒时间早48 h,按MOI为0.2染毒,收获液上清中的抗原含量达193.5 U/ml,病毒滴度达8.43 Log10TCID50/ml;按上清加洗脱液模式收毒,抗原含量可达573 U/ml。结论成功建立了无血清微载体培养Vero细胞生产EV71的方法,为生物反应器培养EV71工艺的建立奠定了基础。     

人牙髓干细胞的无血清培养及其生物学特性

目的使用无血清培养基体外分离培养人牙髓干细胞(dental pulp stem cell,DPSC),并分析其生物学特性。方法分别用有血清培养体系(SCM:含10%胎牛血清的DMEM)和无血清培养体系(SFM:化学成分明确的、无动物源成分的市售培养基Mesen Cult-XF medium)培养人DPSC,倒置显微镜下观察细胞生长、增殖情况及形态特征。细胞传至5代后,检测两种培养基培养的细胞的增殖能力、免疫表型和分化能力。结果 SFM与SCM培养的细胞形态相似,但SFM培养的细胞外形显得纤细、细长,立体感更强;SFM与SCM培养的人DPSC有相似的增殖能力、细胞表型和分化能力,且SFM培养的人DPSC成骨和成软骨分化能力更强。结论本实验表明,SFM能够在体外培养扩增人DPSC,并维持其干细胞特性,包括自我更新能力(集落形成能力)和多向分化潜能,可取代FBS用于细胞治疗及生物医学研究。     

生物反应器无血清悬浮培养MDCK-siat7e细胞工艺的建立

目的建立无血清无蛋白无动物源性培养基BD001悬浮培养MDCK-siat7e细胞的工艺,为MDCK-siat7e细胞的生物反应器规模化培养及病毒性疫苗的研制提供依据。方法采用BD001驯化MDCK-siat7e细胞,建立无血清无蛋白无动物源性MDCK-siat7e细胞库,对细胞库进行常规检定,观察MDCK-siat7e细胞的生长形态;比较不同起始接种密度(4.0×10~5、8.0×10~5、1.6×10~6 cells/ml)悬浮培养,MDCK-siat7e细胞达到平台期的时间、平台期细胞密度及活率;比较不同规模生物反应器(3、15、60 L)无血清无蛋白无动物源性培养MDCK-siat7e细胞对数生长期的比生长速率(μ)、分裂次数(Cd)、葡萄糖比消耗速率(q_(gluc))、乳酸对葡萄糖的转化率(Y_(lac)/g_(luc)),观察细胞的生长和代谢情况。结果建立的无血清无蛋白无动物源性MDCK-siat7e细胞库复苏后细胞平均活率为(96.20±2.95)%。MDCK-siat7e细胞在BD001培养基中复苏传代后生长状态良好,经过24 h潜伏期后,进入对数生长期,第6天进入平台期,第8天达最大细胞密度(6.2×10~6 cells/ml),维持至第12天细胞密度和活率开始下降,进入衰亡期。MDCK-siat7e细胞在无血清培养基中生长良好;不同起始接种密度MDCK-siat7e细胞达到平台期的时间差异有统计学意义(P0.05),平台期细胞密度及活率差异无统计学意义(P0.05);不同规模生物反应器培养的MDCK-siat7e细胞的μ、Cd、q_(gluc)、Y_(lac/gluc)差异均无统计学意义(P0.05),细胞生长代谢良好。结论建立了生物反应器无血清悬浮培养MDCK-siat7e细胞的工艺,为病毒性疫苗生产中采用无血清无蛋白、无动物源性培养基,生物反应器规模化培养MDCK-siat7e细胞提供了一定的实验依据。     

在无血清无蛋白培养基中培养Vero细胞

目的开发在无血清无蛋白培养基(PF)中培养Vero细胞的技术。方法在DMEM/F12培养基中添加酵母提取物和大豆水解物,配制成无血清无蛋白培养基。使用配制好的无血清无蛋白培养基,分别在玻璃、聚乙烯醇缩丁醛(PVB)和聚苯乙烯(PS-TC)培养面上培养Vero细胞,观察细胞生长情况,并绘制细胞生长曲线,以含血清培养基BM为对照。结果与BM培养基比较,在玻璃培养面上,PF培养基不支持Vero细胞生长和分裂;在PVB培养面上,PF培养基支持Vero细胞生长,但不支持分裂;在PS-TC培养面上,PF培养基支持Vero细胞的生长和分裂。结论在PS-TC培养面上,PF培养基适合培养Vero细胞。     

无血清培养Vero细胞及其传代稳定性分析

目的建立无血清无动物源性培养基(virus production-serum-free medium,VP-SFM)培养Vero细胞的工艺,并分析其传代稳定性。方法采用VP-SFM适应培养Vero细胞,建立无血清无动物源性Vero细胞库,对细胞库进行常规检定;绘制VP-SFM培养Vero细胞的生长曲线;比较140、150、160代Vero细胞在VP-SFM中培养的比生长速率(μ)和分裂次数(Cd);比较142、147、153代Vero细胞在VP-SFM中培养的狂犬病病毒滴度;比较无血清与含血清培养140、150、160代Vero细胞的μ和Cd值;分别在250 ml spinner flask中加入2 g/L cytodexⅠ、在3 L生物反应器中加入3 g/L cytodexⅠ培养Vero细胞,观察细胞贴壁和生长情况。结果建立的无血清无动物源性Vero细胞库,细胞密度为4×10~6个/ml,冻存前细胞活率为100%,复苏后细胞平均活率为(94.20±3.95)%,无菌检查和支原体检查合格;细胞在VP-SFM中复苏传代后生长良好,经过24 h潜伏期后,进入对数生长期,第8天进入平台期,第12天达最大细胞密度20.5×10~5个/ml,并维持至第14天,活细胞数开始下降,最大μ值为0.025 4 h~(-1)。Vero细胞在无血清培养基中传代稳定性较好,140、150、160代Vero细胞在VP-SFM培养的μ和Cd值差异无统计学意义(P0.05);142、147、153代Vero细胞在VP-SFM培养的狂犬病病毒滴度差异无统计学意义(P0.05);140、150、160代Vero细胞在无血清和含血清培养基培养的μ和Cd值差异无统计学意义(P0.05)。在生物反应器微载体系统中,采用无血清培养基培养Vero细胞,细胞贴壁及生长状态良好。结论初步建立无血清、无动物源性物质的Vero细胞库,采用方瓶静置培养或微载体搅拌培养,细胞生长状态均良好,传代稳定性也较好。     

无血清培养基与含血清培养基培养CHO细胞的比较

目的对无血清培养基与含血清培养基培养CHO细胞进行比较。方法应用两种培养基采用小方瓶培养CHO细胞,观察细胞维持时间、培养过程的形态变化及对血凝效价的影响。结果应用无血清培养基(A)培养CHO-C28细胞虽然可维持细胞正常生长,但贴壁不好,逐渐降低(A)加量情况可得到相应改善。结论 目前无血清培养基尚不能完全取代含血清培养基用于培养CHO细胞。     

表达乙型肝炎表面抗原的重组CHO细胞无血清培养基的优化及生物反应器培养

目的优化表达乙型肝炎表面抗原(HBsAg)的重组CHO细胞的无血清培养基,并进行生物反应器高密度培养。方法通过对现有重组CHO细胞无血清培养基SFMB的氨基酸、蛋白类激素、蛋白水解物等的优化,建立针对表达HBsAg的重组CHO细胞无血清低蛋白(<10mg/L)培养基SFMC。并利用此培养基在生物反应器中分批、流加、灌注悬浮培养重组CHO细胞,通过最大细胞密度和HBsAg产率评价不同的培养模式。结果 SFMC与原培养基SFMB相比,使重组CHO细胞的最大细胞密度提高了20%,HBsAg表达量提高了25%。在生物反应器培养过程中,灌注培养的重组CHO细胞表达的HBsAg产率为0.70mg/(L·d),较分批和流加培养的0.30mg/(L·d)提高了约133%。结论通过无血清培养基优化及生物反应器高密度培养,可显著提高重组CHO细胞表达HBsAg的效率。     

康宁宣布扩大无血清细胞培养基产品组合

2012年10月15日,康宁公司宣布扩充Mediatech公司的无血清产品组合,增加肝细胞培养基和stemgro。间充质干细胞培养基两种新型细胞培养基。肝细胞培养基针对人原代肝细胞的培养进行了优化,体外培养的人原代肝细胞是研究药物性肝损伤（DILI）的一种成熟体外模型。问充质干细胞培养基旨在更高效地培养扩增来自骨髓、脐带血或脂肪组织的人类间充质干细胞（MSCs）。     

无血清悬浮培养CHO-K1-SFS细胞系的建立及其生物学特性

目的建立无血清悬浮培养CHO-K1-SFS细胞系,并检测其生物学特性。方法将CHO-K1贴壁细胞通过逐步降低血清浓度,获得低血清CHO-K1贴壁细胞,以3×105个/ml接种于含无血清培养基SFM4CHO的150 ml三角瓶中,摇床无血清适应培养,获得CHO-K1-SFS细胞。对该细胞进行生长曲线绘制、微生物污染检测、代谢分析及外源基因表达检测。结果所获得的CHO-K1-SFS细胞系可无血清悬浮培养,以3×105个/ml的初始密度接种,最大增殖浓度可达3.8×106个/ml,平均倍增时间为29.7 h;无细菌、真菌、病毒和支原体污染;对葡萄糖利用率较高,乳酸产生较多;能较好地表达外源基因。结论成功建立了无血清悬浮培养CHO-K1-SFS细胞系,为建立高效的外源基因表达平台奠定了基础。     

无血清微载体培养Vero细胞和H1N1流感病毒条件的优化

目的优化无血清微载体培养Vero细胞和H1N1流感病毒的条件,为Vero细胞流感疫苗的开发奠定基础。方法在搅拌瓶中采用不同的细胞接种量和不同的微载体浓度培养Vero细胞,制备流感病毒,并检测不同的pH值、TPCK-胰酶含量、病毒接种量及病毒收获时间对流感病毒血凝滴度的影响。结果以(1.0～5.0)×105个/ml的Vero细胞接种至浓度为3mg/ml的无血清微载体中,病毒培养液pH值为7.2～7.4,TPCK-胰酶含量为1.0μg/ml,病毒接种量为1.0MOI,并在感染48h后补加TPCK-胰酶,培养72h后收获上清与细胞内病毒,血凝滴度可达1:512。结论已获得了无血清微载体培养Vero细胞和H1N1流感病毒的适宜条件,为应用生物反应器大规模制备流感病毒奠定了基础。     

The Role of MicroRNAs in Breast Cancer Stem Cells

The concept of the existence of a subset of cancer cells with stem cell-like properties, which are thought to play a significant role in tumor formation, metastasis, resistance to anticancer therapies and cancer recurrence, has gained tremendous attraction within the last decade. These cancer stem cells (CSCs) are relatively rare and have been described by different molecular markers and cellular features in different types of cancers. Ten years ago, a novel class of molecules, small non-protein-coding RNAs, was found to be involved in carcinogenesis. These small RNAs, which are called microRNAs (miRNAs), act as endogenous suppressors of gene expression that exert their effect by binding to the 3′-untranslated region (UTR) of large target messenger RNAs (mRNAs). MicroRNAs trigger either translational repression or mRNA cleavage of target mRNAs. Some studies have shown that putative breast cancer stem cells (BCSCs) exhibit a distinct miRNA expression profile compared to non-tumorigenic breast cancer cells. The deregulated miRNAs may contribute to carcinogenesis and self-renewal of BCSCs via several different pathways and can act either as oncomirs or as tumor suppressive miRNAs. It has also been demonstrated that certain miRNAs play an essential role in regulating the stem cell-like phenotype of BCSCs. Some miRNAs control clonal expansion or maintain the self-renewal and anti-apoptotic features of BCSCs. Others are targeting the specific mRNA of their target genes and thereby contribute to the formation and self-renewal process of BCSCs. Several miRNAs are involved in epithelial to mesenchymal transition, which is often implicated in the process of formation of CSCs. Other miRNAs were shown to be involved in the increased chemotherapeutic resistance of BCSCs. This review highlights the recent findings and crucial role of miRNAs in the maintenance, growth and behavior of BCSCs, thus indicating the potential for novel diagnostic, prognostic and therapeutic miRNA-based strategies.     

Hela细胞高密度悬浮培养的研究

应用1.5L Celligen细胞培养罐,通过加大培养基的更换量,实现了Hela细胞高密度悬浮培养,细胞浓度达1.1×10~7/ml,每周可收获10~(10)以上的活细胞。     

Tumour Stem Cells in Breast Cancer

Tumour stem cells (CSCs) are a self-renewing population that plays important roles in tumour initiation, recurrence, and metastasis. Although the medical literature is extensive, problems with CSC identification and cancer therapy remain. This review provides the main mechanisms of CSC action in breast cancer (BC): CSC markers and signalling pathways, heterogeneity, plasticity, and ecological behaviour. The dynamic heterogeneity of CSCs and the dynamic transitions of CSC⁻ non-CSCs and their significance for metastasis are considered.     

Vero细胞无血清培养制备弓形虫排泄-分泌抗原适宜条件的筛选

目的筛选Vero细胞无血清培养制备弓形虫排泄-分泌抗原(ESA)的适宜条件。方法采用拉丁方析因设计。第一部分:在血清浓度为0.5%、1.0%、2.0%、4.0%的培养基中,共培养Vero细胞与弓形虫速殖子,分别于培养3、6、12、24h时,改为无血清培养基,继续培养至第7天,收集培养上清液,制备ESA,并检测蛋白含量。第二部分:在含1.0%血清培养基中共培养Vero细胞与弓形虫速殖子,分别于培养12、24、48、72h时,改为无血清培养基,继续培养至第7、9、11、13天,收集培养上清液,制备ESA,并检测蛋白含量。结果Vero细胞与弓形虫速殖子在1.0%血清浓度培养基中培养12或24h时,无血清培养基继续培养7d,制备的ESA蛋白含量显著高于其他血清浓度(0.5%、2.0%、4.0%)及含血清培养时间(3、6h)。Vero细胞与弓形虫速殖子在含1.0%血清培养基中共培养12、24h,无血清培养基继续培养至第13天,制备的ESA蛋白含量显著高于其他培养时间(48、72h)和无血清培养基继续培养时间(7、9、11d)。结论培养基的血清浓度以及含血清和无血清培养时间是影响体外制备ESA的重要因素。Vero细胞与弓形虫速殖子在1.0%血清浓度培养基中培养12h,无血清培养基继续培养13d,为制备ESA的适宜条件。     

Vero细胞和流感病毒在无血清条件下的微载体培养

目的探索Vero细胞和流感病毒在无血清条件下的微载体培养条件。方法在搅拌瓶中,选择合适的微载体,在无血清条件下培养Vero细胞和流感病毒。观察Vero细胞的生长状况,并检测流感病毒的血凝滴度。结果Vero细胞在Cytodex 3上生长最好,每个微载体上接种10个细胞为最佳接种浓度,以MOI=0.005和0.010 CCID50/细胞接种H1N1流感病毒后,在72h时,培养上清病毒血凝滴度达到最高。结论无血清条件下,Vero细胞在Cytodex 3上生长良好,流感病毒能在Vero细胞上成功培养。     

The Impact of Human Lipoaspirate and Adipose Tissue-Derived Stem Cells Contact Culture on Breast Cancer Cells: Implications in Breast Reconstruction

Background: Autologous fat transfer in the form of lipoaspirates for the reconstruction of the breast after breast cancer surgery is a commonly used procedure in plastic surgery. However, concerns regarding the oncologic risk of nutrient-rich fat tissue are widely debated. Previous studies have primarily focused on studying the interaction between adipose-derived stem cells (ASCs) and breast cancer cells. Methods: In this study, we performed a comprehensive analysis of the paracrine- and contact-based interactions between lipoaspirates, ASCs and breast cancer cell lines. An inverted flask culture method was used to study the contact-based interaction between lipoaspirates and breast cancer cells, while GFP-expressing breast cancer cell lines were generated to study the cell–cell contact interaction with ASCs. Three different human breast cancer cell lines, MCF-7, MDA-MB-231 and BT-474, were studied. We analyzed the impact of these interactions on the proliferation, cell cycle and epithelial-to-mesenchymal (EMT) transition of the breast cancer cells. Results: Our results revealed that both lipoaspirates and ASCs do not increase the proliferation rate of the breast cancer cells either through paracrine- or contact-dependent interactions. We observed that lipoaspirates selectively inhibit the proliferation of MCF-7 cells in contact co-culture, driven by the retinoblastoma (Rb) protein activity mediating cell cycle arrest. Additionally, ASCs inhibited MDA-MB-231 breast cancer cell proliferation in cell–cell contact-dependent interactions. Quantitative real-time PCR revealed no significant increase in the EMT-related genes in breast cancer cells upon co-culture with ASCs. Conclusion: In conclusion, this study provides evidence of the non-oncogenic character of lipoaspirates and supports the safety of clinical fat grafting in breast reconstruction after oncological surgical procedures. In vivo studies in appropriate animal models and long-term post-operative clinical data from patients are essential to reach the final safety recommendations.     

Targeting Breast Cancer Stem Cells Using Naturally Occurring Phytoestrogens

Breast cancer therapies have made significant strides in improving survival for patients over the past decades. However, recurrence and drug resistance continue to challenge long-term recurrence-free and overall survival rates. Mounting evidence supports the cancer stem cell model in which the existence of a small population of breast cancer stem cells (BCSCs) within the tumor enables these cells to evade conventional therapies and repopulate the tumor, giving rise to more aggressive, recurrent tumors. Thus, successful breast cancer therapy would need to target these BCSCs, as well the tumor bulk cells. Since the Women’s Health Initiative study reported an increased risk of breast cancer with the use of conventional hormone replacement therapy in postmenopausal women, many have turned their attention to phytoestrogens as a natural alternative. Phytoestrogens are plant compounds that share structural similarities with human estrogens and can bind to the estrogen receptors to alter the endocrine responses. Recent studies have found that phytoestrogens can also target BCSCs and have the potential to complement conventional therapy eradicating BCSCs. This review summarized the latest findings of different phytoestrogens and their effect on BCSCs, along with their mechanisms of action, including selective estrogen receptor binding and inhibition of molecular pathways used by BCSCs. The latest results of phytoestrogens in clinical trials are also discussed to further evaluate the use of phytoestrogen in the treatment and prevention of breast cancer.