Nano-sphere surface arrays based on GaAs solar cells

In this paper,we present our efforts on simulating and analyzing the effect of two-dimensional nano-sphere surface array on the characteristic of GaAs solar cells.Based on the scattering and diffraction theory of the photonic crystals,the simulation results show that the distance of adjacent nano-spheres(D)has the pronounced influence on the conversion efficiency and exhibits much poor tolerance,the absolutely conversion efficiency is reduced by exceeding of 2%as the D varies from 0 to 1μm,in addition,the lower conversion efficiency(<18%)is exhibited and almost remains unaltered when the D is of>2μm.The radius(R)of nano-spheres demonstrates much great tolerance.For D=0,the solar cells exhibit high conversion efficiency(>20%)and the efficiency is only varied by less than 1%when R is varied in a very wide region of 0.3-1.2μm.One can also find out that there is good tolerance for efficiency around the optimal value of refractive index and there is only about 0.2%decrease in final cell efficiency for around±24%variation in the optimal values,which implys that it does not demand high precision processing equipment and the whole nano-sphere array could be fully complemented using self-assembled chemical methods.

The cultivation and identification of tumor stem cells from neuroblastoma derived tumor spheres

Background and Objective: Since the proposal of the tumor stem cell hypothesis, considerable interest has been devoted to the isolation and purification of tumor stem cells. Tumor stem cell enrichment from primary tumor derived cell spheres has been demonstrated in specific, serum-free media. This goal of this study is to establish a method of cultivating floating tumor spheres from neuroblastoma cells and to confirm that neuroblastoma spheres are rich in tumor stem cells. Methods: Bone marrow aspirates were obtained from pediatric patients diagnosed with stage IV neuroblastoma. Primary tumor cells were isolated and cultivated in serum-free, stem cell-selective medium. Single sphere-forming cells were cultivated under serum-free conditions; their cloning efficiency and monoclonal tumor sphere formation rates were calculated. The expression of stem cell marker genes Oct-4 and Bmi-1 was detected by RT-PCR in sphere-forming cells and parental neurolastoma cells. Sphere-forming cells were injected into the armpit of nude mice with subsequent assessment for tumor growth. Sphere-forming cells were cultivated in differentiation medium containing 5 μmol/L 13-cis retinoic acid; changes in cell morphology were observed. Results: Neuroblastoma cells formed non-adherent neurospheres under serum-free, stem cell-selective conditions after a period of 4 to 6 days. A single cell dissociated from a neurosphere could reform a monoclonal sphere; cloning efficiency and monoclonal sphere formation rates were 55.3% and 26.3%, respectively. RT-PCR results revealed heightened tumor sphere expression of Oct-4 and Bmi-1 as compared with parental tumor cells. Fourteen days after injection of 104 sphere-forming cells into nude mice, a neuroblastoma xenograft formed. Treatment of sphere-forming cells with 13-cis retinoic acid induced a gradual differentiation to neuronal cell morphology. Conclusions: Neuroblastoma derived tumor spheres enrich tumor stem cells and the cultivation of primary neuroblastoma cells in serum-free, stem cell-selective medium is an effective method to dissociate and purify tumor stem cells in vitro.

A Bi-layer Composite Film Based on TiO_2 Hollow Spheres, P25,and Multi-walled Carbon Nanotubes for Efficient Photoanode of Dye-sensitized Solar Cell

A bi-layer photoanode for dye-sensitized solar cell(DSSC) was fabricated, in which TiO_2 hollow spheres(THSs) were designed as a scattering layer and P25/multi-walled carbon nanotubes(MWNTs) as an under-layer. The THSs were synthesized by a sacrifice template method and showed good light scattering ability as an over-layer of the photoanode. MWNTs were mixed with P25 to form an under-layer of the photoanode to improve the electron transmission ability of the photoanode. The power conversion efficiency of this kind of DSSC with bi-layer was enhanced to 5.13 %,which is 14.25 % higher than that of pure P25 DSSC.Graphical Abstract A bi-layer composite photoanode based on P25/MWNTs-THSs with improved light scattering and electron transmission, which will provide a new insight into fabrication and structure design of highly efficient dyesensitized solar cells.

成胶质细胞瘤U87干细胞样细胞的培养及其代谢表型与成瘤能力鉴定

目的培养成胶质细胞瘤U87干细胞样细胞(U87 SLCs),检测其干性标志物的水平、线粒体呼吸能力和体内成瘤能力。方法DMEM/F-12中添加B-27以及生长因子EGF和bFGF作为无血清干细胞培养基培养U87 SLCs;悬浮培养U87 SLCs使用神经球培养法,贴壁培养U87 SLCs通过在培养表面包被Matrigel基质胶实现;通过RT-qPCR和Western blot检测培养物的干性标志物mRNA和蛋白质水平;通过流式细胞测量术检测培养物中CD133+细胞的比例;通过Seahorse实时细胞代谢分析检测细胞耗氧速率的变化;通过接种动物皮下移植瘤验证细胞成瘤能力的改变。结果干细胞培养基中的U87 SLCs在1周内即会成长为典型的细胞球形态,细胞球在培养过程中会不断增大;在贴壁剂合适的浓度下,U87 SLCs可以在干细胞培养基中完好地平铺贴壁增殖;CD133、nestin、OLIG2、CD44、CD15、整合素α6(ITGA6)等干性标志物的mRNA表达水平在两种方式培养后与U87相比均显著提升(P<0.05),CD133和nestin的蛋白水平在两种方式培养后也均升高(P<0.05);U87 SLCs展现出了更高的线粒体储备呼吸能力(P<0.05);U87 SLCs能够以更少的接种细胞数形成更大的皮下肿瘤(P<0.05),U87 SLCs体内增殖更加迅速,具有更强的成瘤能力。结论U87 SLCs具有典型的干性特征,是一个良好的干性更高的肿瘤细胞模型。

DMSCs三维培养方法及其在组织再生和疾病治疗中应用的研究进展

牙源性间充质干细胞(DMSCs)是来源于神经嵴外胚层的间充质干细胞,具有优越的自我更新和多向分化的能力,被广泛应用于组织工程和再生医学研究。利用三维培养方法可对DMSCs进行大量体外扩增以满足研究和治疗的需要。与传统的二维培养方法比较,三维培养技术可更有效地模拟干细胞在体内所处的结构和微环境,从时间和空间上共同调控干细胞的增殖及分化。近年来开展的体外三维培养方法较多,悬滴培养法操作简单,但较难控制培养组织的气象环境;微流控芯片可更好地控制细胞参数,但成本高昂,且存在技术平台的难题而难以广泛应用;磁悬浮培养费用低廉,操作简便,细胞成球速度快,但由于磁化作用难以用来定量分析。其他三维培养方法还包括旋转细胞培养系统、离心成球培养法、液体覆盖法和人工支架法等,上述培养方法都存在不同的优势和一定的局限性。现对体外三维培养DMSCs的不同方法及其在不同组织再生和疾病治疗中的应用进行综述,为DMSCs功能的精准调控和再生医学研究提供参考。

Radiobiological characteristics of cancer stem cells from esophageal cancer cell lines

AIM:To study the cancer stem cell population in esophageal cancer cell lines KYSE-150 and TE-1 and identify whether the resulting stem-like spheroid cells display cancer stem cells and radiation resistance characteristics.METHODS:A serum-free medium(SFM)suspension was used to culture esophageal cancer stem cell lines and enrich the esophageal stem-like spheres.A reverse transcription polymerase chain reaction assay was used to detect stem cell gene expression in the spheroid cells.Radiosensitivity of stem-like spheres and parental cells were evaluated by clonogenic assays.Furthermore,different cells after different doses of irradiation were tested to evaluate the change in sphere formation,cell cycle and CD44+CD271+expression of tumor stem-like spheroid cells using flow cytometry beforeand after irradiation.RESULTS:The cells were observed to generate an increased number of spheres in SFM with increasing cell passage.Radiation increased the rate of generation of stem-like spheres in both types of cells.The average survival fraction(SF2)of the cultured KYSE-150compared with TE-1 stem-like spheres after 2 Gy of radiation was 0.81±0.03 vs 0.87±0.01(P<0.05),while the average SF2 of KYSE-150 compared with TE-1 parental cells was 0.69±0.04 vs 0.80±0.03,P<0.05.In the esophageal parental cells,irradiation dose-dependently induced G2 arrest.Stem-like esophageal spheres were resistant to irradiation-induced G2arrest without significant changes in the percentage population of irradiated stem-like cells.Under irradiation at 0,4,and 8 Gy,the CD44+CD271+cell percentage for KYSE150 parental cells was 1.08%±0.03%vs1.29%±0.07%vs 1.11%±0.09%,respectively;the CD44+CD271+cell percentage for TE1 parental cells was 1.16%±0.11%vs 0.97%±0.08%vs 1.45%±0.35%,respectively.The differences were not statistically significant.Under irradiation at 0,4,and 8 Gy,the CD44+CD271+cell percentage for KYSE-150 stemlike spheres was 35.83%±1.23%vs 44.9%±1.67%vs 57.77%±1.88%,respectively;the CD44+CD271+cell percentage for TE1 stem-like spheres was 16.07%±0.91%vs 22.67%±1.12%,16.07%±0.91%vs33.27%±1.07%,respectively.The 4 and 8 Gy irradiated KYSE-150 and TE-1 stem-like spheres were compared with the 0 Gy irradiated group,and the differences were statistically significant(P<0.05).CONCLUSION:The KYSE-150 and TE-1 stem-like spheres are more radioresistant than their parental cells which may suggest that cancer stem cells are related to radioresistance.

Pluripotent stem cell-derived neural stem cells: From basic research to applications

Basic research on pluripotent stem cells is designed to enhance understanding of embryogenesis, whereas applied research is designed to develop novel therapies and prevent diseases. Attainment of these goals has been enhanced by the establishment of embryonic stem cell lines, the technological development of genomic reprogramming to generate induced-pluripotent stem cells, and improvements in in vitro techniques to manipulate stem cells. This review summarizes the techniques required to generate neural cells from pluripotent stem cells. In particular, this review describes current research applications of a simple neural differentiation method, the neural stem sphere method, which we developed.

CD133^+ gallbladder carcinoma cells exhibit self-renewal ability and tumorigenicity

AIM:To identify cancer stem cells(CSCs) in human gallbladder carcinomas(GBCs).METHODS:Primary GBC cells were cultured under serum-free conditions to produce floating spheres.The stem-cell properties of the sphere-forming cells,including self-renewal,differentiation potential,chemoresistance and tumorigenicity,were determined in vitro or in vivo.Cell surface expression of CD133 was investigated in primary tumors and in spheroid cells using flow cytometry.The sphere-colony-formation ability and tumorigenicity of CD133+ cells were assayed.RESULTS:In vitro culture experiments revealed thatfloating spheroids were generated from primary GBC cells,and these sphere-forming cells could generate new progeny spheroids in serum-free media.Spheroid cells were differentiated under serum-containing conditions with downregulation of the stem cell markers Oct-4,Nanog,and nestin(P < 0.05).The differentiated cells showed lower spheroid-colony-formation ability than the original spheroid cells(P < 0.05).Spheroid cells were more resistant to chemotherapeutic reagents than the congenetic adherent cells(P < 0.05).Flow cytometry showed enriched CD133+ population in sphereforming cells(P < 0.05).CD133+ cells possessed high colony-formation ability than the CD133-population(P < 0.01).CD133+ cells injected into nude mice revealed higher tumorigenicity than their antigen-negative counterparts(P < 0.05).CONCLUSION:CD133 may be a cell surface marker for CSCs in GBC.

Preparation of silica-coated CdSe QDs for cell imaging applications

CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, while amino groups were introduced synchronously onto the nanoparticles by copolymerization of 3-aminopropyl- trimethoxysilane and tetraethyl orthosilicate. The results of TEM imaging, fluorescent spectroscopy and photostability tests show that the QDs are of uniform spherical size (200±8 nm), monodispersity, and high fluorescence and photostability.

靶向胃癌干细胞单克隆抗体2C12的鉴定及功能研究

目的:研究胃癌干细胞的功能性单克隆抗体2C12体外功能实验,为胃癌干细胞的靶向治疗提供候选单抗药物。方法:以胃癌细胞系SNU-5为细胞模型,流式细胞术检测其亲本细胞和通过无血清悬浮培养的球体细胞中2C12+细胞的表达水平,双色细胞免疫荧光检测单抗2C12和CD90识别的抗原在SNU-5细胞中的表达情况。流式细胞术分选SNU-5细胞中2C12+和2C12-细胞,采用无血清悬浮培养成球实验和Transwell小室法分别检测其自我更新能力和侵袭能力。用单抗2C12处理SNU-5的球体细胞后,检测其对SNU-5的球体细胞自我更新能力和侵袭能力的影响。结果:2C12+细胞在SNU-5的球体细胞中的表达水平明显高于亲本细胞。免疫荧光结果显示单抗2C12识别的抗原分子能与CD90在SNU-5细胞上共定位。流式细胞术分选结果表明SNU-5细胞中2C12+细胞成球数明显高于2C12-细胞(103.3±9.07 vs 50.67±5.86)(P<0.01),侵袭能力也明显较高(209.3±12.9 vs 99.0±3.61)(P<0.01)。对2C12单抗的体外功能研究发现,不同浓度的单抗2C12(0μg/mL、20μg/mL、40μg/mL)能显著抑制SNU-5的球体细胞的成球能力(122.0±5.66、83.0±5.66、59.0±4.24),抑制率达到31.97%和51.64%,同时侵袭能力也显著降低(178.0±8.49、106.5±5.0、78.0±2.83),抑制率达到40.17%和56.18%。结论:单抗2C12是一株抗胃癌干细胞的功能性单抗,能够显著抑制胃癌干细胞的干性相关特征,为胃癌干细胞靶向治疗的候选抗体药物。

无血清悬浮球状培养方法在人源前列腺癌干细胞富集纯化中的应用

目的:通过无血清悬浮球状培养方法富集纯化人源前列腺癌干细胞并进行小鼠体内外实验验证。方法:采用前列腺癌DU145细胞系,通过无血清悬浮球状培养的方法分离富集、培养纯化出肿瘤干细胞微球(Tumor spheres)。通过流式细胞仪鉴定干细胞表型,并采用动物成瘤实验,将不同数量级的DU145细胞和Tumor spheres细胞接种到NOD/SCID小鼠双侧腋下,观察成瘤率和成瘤速度。对分离富集、培养纯化的Tumor spheres进行诱导分化、增殖水平、活性氧簇、细胞周期检测。为进一步明确Tumor spheres的肿瘤干细胞特性,采用Western blot法检测特异性蛋白的表达,RT-PCR法检测相关mRNA表达。结果:采用无血清悬浮球状培养的方法可使对数生长期DU145细胞分离富集形成Tumor spheres,培养3代可达到纯化的目的,流式细胞技术鉴定其表达前列腺癌干细胞表型CD44(+)CD24(-/low)比例为(63±1)%,明显高于DU145细胞[(33±4)%](P<0.05)。动物成瘤实验显示,接种Tumor spheres侧肿瘤成瘤速度和成瘤率均高于接种DU145细胞侧。Tumor spheres具有更强的自我更新能力和分化潜能,细胞周期检测发现Tumor spheres中(81.67±0.68)%处于细胞周期的G_(0)/G_(1)期(P<0.05),同时Tumor spheres具有更低水平的活性氧簇ROS水平(P<0.05)。Tumor spheres高表达肿瘤干细胞HES1蛋白(P<0.05),Tumor spheres高表达肿瘤干细胞相关Notch1、HES1、HIF-1α、Sox2、Jagged1的mRNA(P<0.05)。结论:无血清悬浮球培养分离纯化DU145肿瘤干细胞的方法简便易行、获取量大、成瘤率高,Tumor spheres具有明确的肿瘤干细胞特性,可作为前列腺癌肿瘤干细胞研究的良好实验模型。

骨三维药物筛选模型的特性、功能及应用

背景:临床上骨骼相关疾病药物的开发是个漫长的过程,传统的二维模型药物筛选的效果已经不能满足需求,改进研发的各种三维模型均有其优缺点和相关应用,但到目前为止还没有一个理想的实验模型可以用于所有骨骼相关疾病的药物筛选。目的:综述近几年相关文献,总结骨二维模型和三维模型的基本特性以及对细胞功能的可能影响,重点综述目前常见的骨三维模型以及其在实际骨骼系统疾病中的药物筛选应用,以期为将来骨三维模型在药物筛选中的应用和改进提供一定帮助。方法:检索PubMed数据库中的相关英文文章,英文检索词为“bone,skeleton,three-dimensional models,models,drug screening,drug selection”;检索中国知网及万方数据库相关中文文献,中文检索词为“骨、骨骼、模型、三维模型、药物筛选”,并结合文献追溯法查找部分文献进行综述分析。结果与结论:①骨二维模型和三维模型的物理特性不同,二维模型基质一般是固定的,三维模型基质则是可调节的,二者对细胞的功能方面影响不同。②骨二维模型的构建和生产较为容易,但其缺乏典型的三维微观结构,缺少与周围细胞及细胞外基质的相互联系,因此只能适应于细胞水平研究。③骨二维模型和三维模型培养的骨组织有生物学差异,二维状态下骨细胞或者诱导成骨细胞都是扁平状的,而三维模型更接近骨组织的自然细胞外基质的结构,能更准确地表现药物反应。④目前常见的骨三维模型包括细胞球、水凝胶、生物反应器和微流体芯片等,它们的构建方法不同,在药物筛选方面各有优势。⑤目前常见的骨三维模型已经应用于骨骼相关疾病的药物筛选,不同疾病对不同三维模型的需求不同,例如在骨质疏松症的药物筛选中,支架和水凝胶的可降解和可持续性更能达到药物筛选的效果。

RNA去甲基化酶FTO抑制剂对胶质母细胞瘤干细胞功能的影响

目的分析m^(6)A去甲基化酶FTO的抑制剂(FB23-2)对人胶质母细胞瘤干细胞活性的影响。方法运用CCK-8法和神经球形成实验检测FB23-2和替莫唑胺对GSC的影响;体外有限稀释实验检测FB23-2对GSC自我更新的影响;EdU法检测FB23-2对GSC增殖的影响;流式细胞术检测FB23-2对GSC凋亡的影响。结果CCK-8结果显示,FB23-2能够有效抑制GSC的细胞活性,其IC_(50)分别为7.11μmol·L^(-1)和4.63μmol·L^(-1)。成球实验证明,FB23-2处理组的GSC神经球的大小和数量较对照组明显减少。体外有限稀释实验表明,FB23-2可有效抑制GSC的自我更新能力;EdU参入实验显示,与对照组相比,处理组分别降至(70.59±13.74)%和(50.33±4.53)%。流式细胞术检测处理组细胞的凋亡率分别为(12.16±1.90)%和(16.77±1.17)%。结论FTO抑制剂FB23-2可抑制GSC的生长和自我更新能力,靶向FTO可能是清除GSC的潜在策略之一。

鼻咽癌肿瘤干细胞样细胞亚群的分离及初步鉴定

目的:分离和鉴定具有肿瘤干细胞特性的鼻咽癌球形成细胞亚群。方法:利用无血清干细胞球悬浮培养技术从不同分化程度鼻咽癌细胞株中分离成球细胞,然后利用MTT法,软琼脂克隆形成实验,分别评价成球细胞的耐药性、克隆形成能力,最后利用RT-PCR和免疫荧光细胞技术分析干性基因及Wnt信号通路关键转录因子β-catenin在成球及未成球细胞中的表达情况。结果:低分化鼻咽癌细胞含有较高成球细胞,而高分化细胞株CNE-1中未见成球细胞。与CNE-2相比较,CNE-2S(来源于CNE-2的成球细胞)具有较强的抗肿瘤药物耐药性、克隆形成能力、高表达干性基因,且β-catenin在胞浆和核内都呈高表达。结论:本研究分离到干细胞样鼻咽癌成球细胞亚群,为最终靶向杀灭鼻咽癌肿瘤干细胞提供了可能。

食管癌细胞株中肿瘤干细胞样细胞的分离培养及生物学鉴定

目的:用无血清培养基方法从人食管癌细胞株KYSE-150、TE-1中分离富含肿瘤干细胞的细胞球并鉴定其生物学特性。方法:运用无血清培养基培养KYSE-150、TE-1细胞,观察细胞球的生成及在有血清培养基中的分化情况,利用MTT法以及Transwell小室法研究食管癌细胞球的增殖情况和侵袭能力,流式细胞仪检测分子标志CD44、CD271的表达。结果:KYSE-150、TE-1细胞在无血清培养基培养条件下可以获得可稳定传代的细胞球,细胞球细胞的增殖能力和侵袭能力均高于其亲本细胞;无血清培养基培养下KYSE-150细胞球中CD44+、CD271+、CD44+CD271+细胞分别为(64.92±11.04)%、(28.27±6.79)%、(24.07±5.39)%,均显著高于亲本细胞[(37.04±6.30)%、(3.69±0.49)%、(1.64±0.11)%,P均<0.05]。TE-1细胞球中CD44+、CD271+、CD44+CD271+细胞占(6.41±0.87)%、(2.58±0.17)%、(0.27±0.53)%,均显著高于亲本细胞[(1.87±0.18)%、(0.44±0.10)%、(0.09±0.02)%,P均<0.05]。结论:应用无血清培养基可以从KYSE-150、TE-1细胞系中分离出具有干细胞特性的食管癌细胞球,CD44、CD271分子可能是食管癌干细胞的标志。

无血清培养的大肠癌Colo205细胞生成肿瘤干细胞球的研究

目的通过含生长因子的无血清培养基(SFM)培养大肠癌Colo205细胞,分离并扩增出肿瘤干细胞球。方法SFM培养大肠癌Colo205细胞,以含血清培养基(SSM)组为对照。观察细胞形态,检测正常肠道干细胞标志Musashi-1的表达,更换培养基为SSM诱导其分化,分别检测SFM组细胞分化前、分化后以及SSM组细胞表面标志CD133、CD44表达的改变,分析各细胞周期的比例,最后进行核型分析。结果Colo205细胞能在SFM中存活、增殖并形成肿瘤干细胞球,高表达Musashi-1,SFM组细胞分化前CD133、CD44的表达高于SSM组和SFM组分化后,差异有统计学意义(P<0.05),SFM组分化后与SSM组相比差异无统计学意义(P>0.05)。细胞周期分析发现肿瘤干细胞球处于高增殖状态,核型分析发现SFM组细胞与SSM组细胞染色体条数未见明显差别。结论含生长因子的SFM培养Colo205细胞,可生成肿瘤干细胞球,这种细胞球富集了肿瘤干细胞。

新生小鼠海马神经干细胞体外培养条件下的增殖与分化

背景:神经干细胞移植可用于中枢神经损伤的临床治疗。目的:观察新生小鼠海马神经干细胞在体外培养条件下的增殖和分化。方法:从新生昆明小鼠海马取材,采用机械分离法对原代细胞进行无血清培养,采用机械法复合酶消化法对原代细胞进行传代,以体积分数为10%胎牛血清诱导分化。免疫荧光行巢蛋白、β-微管蛋白Ⅲ和胶质纤维酸性蛋白染色,对培养的细胞进行鉴定。CCK-8法检测神经干细胞增殖能力。结果与结论:从新生小鼠海马分离得到的细胞具有连续传代形成克隆球的能力,克隆球呈巢蛋白免疫反应阳性;加入胎牛血清可诱导分化为β-微管蛋白Ⅲ和胶质纤维酸性蛋白阳性细胞。提示实验成功建立了体外培养新生小鼠海马组织分离和培养神经干细胞的方法,培养的神经干细胞在体外培养条件下保持着自我增殖和分化的潜能。

低温保护剂对神经干细胞球添加过程的模拟分析

建立了神经干细胞球的低温保护剂添加模型。通过计算研究了在保护剂添加过程中,神经球中不同位置的细胞体积变化情况,以及细胞内外浓度和细胞膜两侧浓差随时间和空间的变化情况;并分析了影响细胞体积变化的因素,利用该模型进行了保护剂添加程序的优化。结果表明细胞外的保护剂浓度变化较快,在球表面处不到10s接近平衡,接近球中心处15s后接近平衡;由于跨膜传质阻力的影响,胞内的保护剂浓度变化较为平缓。减小Lp和增大ω可以显著改善保护剂添加过程的细胞体积变化,神经球尺寸对细胞体积变化影响较小。添加高浓度保护剂时,可以采用等渗透压差、渗透时间间隔逐渐减小的分步添加方法,分步添加方法以四步法较好。理想的连续梯度添加方案应是低浓差和短添加时间的组合,凸曲线添加方案是一种合适的添加方法。

辐射与悬浮球培养联合纯化乳腺癌干细胞

目的:利用悬浮球培养联合不同辐射模式,高度纯化人乳腺癌MCF-7细胞中辐射抵抗的CD44+/CD24-/low乳腺癌干细胞。方法:利用含细胞因子的无血清培养体系培养MCF-7细胞,将培养形成的球囊细胞连续传代,选择第2代球囊细胞分别行2Gy×4次及单次8Gy照射。利用滤网收集存活细胞生成的微球囊,流式细胞仪检测纯化后微球囊中CD44+/CD24-/low细胞的含量,克隆形成检测及单击多靶模型曲线拟合分析纯化后微球囊细胞的辐射敏感性。结果:单纯悬浮球培养与联合X线照射组之间CD44+/CD24-/low细胞的含量差异存在显著性(P﹤0.05),联合组高度纯化CD44+/CD24-/low细胞;多次分割及单次大剂量照射对CD44+/CD24-/low细胞的富集作用差异无显著性(P=0.303)。纯化细胞照射后存活分数显著高于贴壁MCF-7细胞。结论:辐射联合悬浮球培养进一步纯化辐射抵抗的CD44+/CD24-/low乳腺癌干细胞的方法是可行的。

基因芯片筛选胃癌及肿瘤球细胞差异表达基因

目的:利用基因芯片技术筛选人胃癌细胞HGC-27及其肿瘤球细胞的差异表达基因。方法:无菌条件下体外培养人胃癌细胞HGC-27及其肿瘤球细胞,Trizol试剂提取两种细胞的总RNA并纯化,按Gene-Chip IVT Express Kit说明对总RNA进行杂交,所得荧光信号用Cluster和TreeView软件进行分析和显示。结果:按差异显著性标准(差异为2倍),以人胃癌细胞为对照,在肿瘤球细胞中有610个基因表达上调,1135个基因表达下调,涉及细胞生长、信号传导、肿瘤形成等多个方面。结论:人胃癌细胞HGC-27与其肿瘤球细胞存在基因表达的差异,肿瘤球细胞与肿瘤的形成相关。