磁珠分选U251细胞系中的CD133+细胞及其生物学特性

背景：脑肿瘤干细胞理论认为,脑肿瘤干细胞是脑肿瘤细胞中“种子”细胞,是脑肿瘤发生、浸润和复发的关键细胞。 目的：观察人多形性胶质母细胞瘤U251细胞系中CD133⁺细胞的增殖、分化及体内致瘤性等生物学特性。 方法：运用磁珠分选技术分选U251细胞系中的CD133⁺和CD133^-细胞亚群;MTT法绘制两个亚群细胞的生长曲线;单克隆形成率实验检测2个亚群细胞的增殖能力;免疫荧光检测CD133⁺细胞亚群的多向分化能力;裸鼠移植实验检测2个亚群细胞在裸鼠体内致瘤性的差异。 结果与结论：U251细胞系中只有约4.5%的CD133⁺细胞;分选后的CD133⁺细胞能增殖形成典型的脑肿瘤干细胞球,生长曲线显示CD133⁺细胞增殖能力明显强于CD133^-细胞;单克隆形成率实验显示CD133⁺细胞能形成脑肿瘤干细胞球的细胞比率达到78.5%~92.4%,而CD133^-细胞仅有0.8%~2.4%;CD133⁺细胞能分化为具有GFAP和NeuN成熟表型的肿瘤细胞;CD133⁺的致瘤率为71.42%,而CD133^-细胞无致瘤性。提示U251细胞系中存在少量具有增殖、多向分化与体内致瘤能力的CD133⁺细胞,CD133⁺细胞是符合肿瘤干细胞定义的细胞亚群。     

CD133和CD44在结直肠癌细胞中的表达及其与患者5年生存率的相关性分析

目的: 探讨不同CD133/CD44细胞亚群的成瘤能力及CD133、CD44的表达水平对根治性结直肠癌患者术后生存率的影响,明确CD133和CD44作为结直肠癌肿瘤干细胞表面标志物的意义。方法: 利用流式细胞术分选出SW480细胞系中CD133和CD44标记的不同细胞亚群,比较其在裸鼠皮下成瘤情况;并利用免疫组化的方法观察CD133和CD44在90例结直肠癌患者石蜡切片标本的表达情况,对CD133、CD44与患者临床病理资料及生存率进行分析。结果: CD133⁺CD44⁺细胞群成瘤能力明显优于其它各组。CD133和CD44均在细胞膜上表达,两者均与患者性别、年龄 、肿瘤位置、肿瘤大小、浸润深度、淋巴结转移、肝转移、肿瘤分化程度及UICC分期无关(P＞0.05)。Kaplan-Meier生存分析法显示,CD133高表达组5年生存率为45.2%,CD133低表达组5年生存率为83.8%,两者有明显差异(P＜0.01);而CD44高表达组5年生存率(75.6%)与低表达组(70.1%)无明显差异(P＞0.05);其中CD133/CD44同时高表达者5年生存率明显较差(P＜0.01)。Cox风险回归模型分析结果表明,CD133、肝转移、分化程度及淋巴结转移是影响结直肠癌患者预后的几个独立危险因素(P＜0.05)。结论: CD133可作为结直肠癌肿瘤干细胞的良好标志物。CD133是影响结直肠癌患者预后的独立危险因素,其表达水平越高,预后越差;尽管CD44与结直肠癌患者预后无明显相关性,但联合检测CD133/CD44却能更好地判断患者的预后情况。     

人鼻咽癌CD133+干细胞的生物学特性及意义**

背景：有研究表明肿瘤细胞株中存在肿瘤干细胞,是肿瘤复发、转移的根源,但人鼻咽癌细胞株CNE-2中肿瘤干细胞的表达及生物学特性至今少有报道。 目的：观察人鼻咽癌CD133+干细胞生物学特性及意义。 方法：采用流式细胞仪检测人鼻咽癌细胞株CNE-2中CD133的表达情况。免疫磁珠分选技术获得人鼻咽癌CD133+干细胞,分别采用无血清培养法、CCK-8法、平板克隆形成试验及裸鼠体内成瘤实验检测CD133+干细胞的体外增殖及体内成瘤能力,并将其与CD133-及未分选鼻咽癌细胞进行比较,以了解CD133+干细胞的生物学特性。 结果与结论：免疫磁珠富集的CD133+细胞在无血清培养基中呈悬浮生长,并可以形成肿瘤干细胞球。CD133+细胞与CD133-细胞比较具有较高的克隆形成能力(P < 0.01);CD133+细胞在裸鼠体内的成瘤率高于CD133-细胞(P < 0.05)。结果证实,鼻咽癌CD133+干细胞能在体外分离培养,形成干细胞球,增殖能力强,在裸鼠体内具有极强的成瘤能力。 关键词：鼻咽癌;肿瘤干细胞;增殖;生物学特性;干细胞培养 doi:10.3969/j.issn.1673-8225.2012.06.013     

卵巢癌细胞中CD90+肿瘤干细胞的生物学特性

背景：肿瘤干细胞与卵巢癌的发生和发展等之间存在十分密切的联系,CD90+是一种重要的肿瘤干细胞标志物。 目的：探索卵巢癌细胞中CD90+肿瘤干细胞生物学特性。 方法：获得原代卵巢癌细胞并进行分析,对人卵巢癌细胞系SKOV3和原代卵巢癌细胞的CD133和CD90阳性率进行流式细胞术检测,分选获得CD90+和CD90-细胞,并通过反转录PCR法对其干细胞和上皮间质化相关基因mRNA的相对表达情况进行检测。通过Transwell小室侵袭试验对细胞侵袭能力进程观察,利用克隆形成试验对细胞增殖分化能力进行观察,利用悬浮成球试验对干细胞潜能进行观察。并通过免疫缺陷小鼠体内有限稀释成瘤试验,对成瘤时间以及成瘤率进行观察。 结果与结论：SKOV3细胞的CD133和CD90阳性率均显著低于原代卵巢癌细胞。SKOV3细胞系CD90+干细胞相关基因mRNA相对表达CD133和OCT4均显著高于SKOV3细胞系CD90-干细胞;原代卵巢癌细胞CD90+干细胞中CD44、CD133、乙醛脱氢酶1和OCT4均显著高于原代卵巢癌细胞CD90-干细胞。SKOV3细胞系CD90-和CD90+干细胞的上皮间质化相关基因mRNA相对表达水平差异有显著性意义,原代卵巢癌细胞CD90-和CD90+干细胞的上皮间质化相关基因mRNA相对表达水平差异有显著性意义。随着接种细胞数量的增加,CD90-和CD90+细胞成瘤率呈现出不断上升的情况,成瘤时间则不断下降。其中,CD90+干细胞的上升较之CD90-干细胞更为显著。SKOV3细胞系和原代卵巢癌细胞的CD90+干细胞穿膜细胞数、细胞克隆数、悬浮成球数量均显著大于CD90-干细胞。提示卵巢癌细胞中CD90+干细胞可高表达干细胞相关基因和间质属性基因,并具备较高的侵袭、增殖分化能力以及成瘤能力和较大的干细胞潜能。 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

X射线增强CD133~-鼻咽癌细胞干样能力的研究

目的探讨CD133~-鼻咽癌细胞经X射线处理后,其干样相关潜能是否得到增强。方法采用免疫磁珠法分选人鼻咽癌CNE-1细胞株,采用流式细胞仪检测分选后细胞CD133的表达率,并通过侵袭能力分析及体内成瘤实验鉴定其干性。采用4 Gy的X射线照射非肿瘤干细胞的CD133~-鼻咽癌细胞,通过侵袭能力分析及体内成瘤实验观察照射前后其干性特征变化,采用RT-PCR检测其CD133、SOX2及OCT4 mRNA表达变化。结果流式细胞仪检测结果提示CD133~+细胞及CD133~-细胞亚群,其CD133表达分别为97.72%±0.82%和1.63%±0.66%。CD133~+细胞亚群其侵袭能力及体内成瘤能力明显强于CD133~-细胞亚群。经电离辐射后,CD133~-细胞亚群其侵袭能力及体内成瘤能力明显增加。RT-PCR结果显示,照射后CD133、SOX2及OCT4 mRNA的表达水平明显上调。结论在体外,X射线可通过上调干样相关基因表达,从而增强CD133~-鼻咽癌细胞的干样相关潜能。     

RA患者外周血CD8＋CD28-和CD4＋CD25＋调节性T细胞的表达及疾病活动性指标相关性分析

目的：检测类风湿性关节炎（RA）患者外周血CD8＋CD28-、CD4＋CD25＋调节性T细胞亚群,探讨其与临床活动性指标的关系。方法：采用流式细胞术检测台州医院RA患者外周血CD8＋CD28-、CD4＋CD25＋ T细胞亚群比例,探讨调节性T细胞与RA活动性、类风湿因子（RF）、免疫球蛋白（Ig）、C反应蛋白（CRP）、补体C3、抗CCP抗体、抗核抗体（ANA）、血小板（PLT）及血沉（ESR）的关系。结果：活动期RA患者外周血CD4＋CD25＋调节性T细胞亚群比例显著低于正常对照组（P〈0.01）,但稳定期RA患者与正常对照组结果差异无统计学意义（P〉0.05）。活动期和稳定期RA患者CD8＋CD28-与正常对照组相比较,结果无统计学意义（P〉0.05）;CD4＋CD25＋与CRP密切相关（r=-0.593,P〈0.05）,CD8＋CD28-与ESR相关系数呈弱相关。CD4＋CD25＋和CD8＋CD28-细胞与RF、IGG、C3、ANA、anti-CCP和PLT未见明显相关性。结论：活动期RA患者外周血CD4＋CD25＋ T细胞亚群比例减少,CD4＋CD25＋ T细胞可能与类风湿性关节炎疾病进展有关。     

CD133+卵巢癌干细胞样细胞在血管内皮细胞中的分化

背景：大量研究证实,新生血管形成在肿瘤的生长、浸润以及转移过程中发挥重要作用。 目的：探讨CD133+卵巢癌干细胞样细胞向血管内皮细胞分化的特点。 方法：通过无血清培养方法从卵巢癌A2780细胞株中成功诱导出CD133⁺卵巢癌干细胞样细胞,在体外接种于铺或不铺Matrigel基质胶的96孔板内,观察不同时间点CD133⁺卵巢癌干细胞样细胞和人脐静脉内皮细胞形成管腔样结构能力。通过裸鼠皮下移植实验,免疫荧光法观察CD133⁺卵巢癌干细胞样细胞在卵巢癌血管新生中的作用。 结果与结论：CD133⁺卵巢癌干细胞样细胞和人脐静脉内皮细胞(阳性对照)在未铺 Matrigel基质胶上并不能形成相应的管腔结构,且不表达内皮细胞标志物CD31,在Matrigel基质胶上能够形成相对稳定的管腔结构,CD31表达明显。CD133⁺卵巢癌干细胞样细胞接种裸鼠皮下成瘤后,可观察到肿瘤组织中有人源性CD31的表达。结果表明CD133⁺卵巢癌干细胞样细胞能够分化为血管内皮细胞,参与肿瘤血管重建。中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

干细胞表面标志CD133在肝癌中的表达及其阳性亚群增殖特性北大核心

背景:以CD133为标志物,利用其蛋白特异性特征可对不同的肿瘤干细胞进行分选和研究。目的:探讨干细胞表面标志CD133在肝癌中的表达及其阳性亚群的体外增殖特性。方法:对人肝癌MHCC97-H细胞株进行培养和分选,分别获得CD133^+与CD133^-MHCC97-H细胞,检测CD133表达及细胞迁移侵袭能力;培养14 d,检测细胞克隆形成率;培养7 d,检测细胞增殖及Notch基因蛋白表达。将CD133^+与CD133^-MHCC97-H细胞分别接种于裸鼠背部皮下,4周后,检测成瘤情况。结果与结论:(1)CD133表达与细胞克隆形成率:CD133^+MHCC97-H细胞CD133表达率、克隆形成率均显著大于CD133^-MHCC97-H细胞(P<0.05);(2)细胞增殖:CD133^+MHCC97^-H细胞培养3-7 d的吸光度值大于CD133^-MHCC97-H细胞(P<0.05);(3)细胞迁移侵袭:CD133^+MHCC97-H细胞迁移与侵袭实验的透膜细胞数均显著多于CD133^-MHCC97-H细胞(P<0.05);(4)Notch基因蛋白:CD133^+MHCC97-H细胞Notch基因蛋白表达多于CD133^-MHCC97-H细胞(P<0.05);(5)成瘤实验:CD133^-MHCC97-H细胞组成瘤体积大于CD133^-MHCC97-H细胞组(P<0.05);(6)结果表明:CD133阳性肝癌细胞亚群具有较强的体外增殖特性,具有一定的肿瘤干细胞特性,并有较强的侵袭、转移及致瘤能力。     

健康双生子外周血CD4^＋和CD8^＋ T细胞亚群相对计数遗传度研究

目的分析围生期及生命早期环境因素与外周血CD4＋、CD8＋T细胞相对计数的关系,估计CD4＋和CD8＋T细胞亚群的遗传度。方法采用双生子研究设计,经纳入与排除标准选取在新疆医科大学第一附属医院、乌鲁木齐市妇幼保健医院、新疆维吾尔自治区人民医院、中国人民解放军乌鲁木齐总医院和乌鲁木齐市第一人民医院出生的健康双生子。收集研究对象一般家庭状况、母亲孕期及分娩状况、出生时状况等信息,在双生子满1周岁时进行体检。体重和身高等体格发育指标依照＂1995年中国九市7岁以下儿童体格发育调查研究＂标准进行测量。测定外周血CD4＋和CD8＋T细胞亚群相对计数,并通过微卫星DNA基因分型技术进行卵型鉴定。CD4＋和CD8＋T细胞亚群的遗传度估计应用Mx软件进行分析。结果研究期间共有172对双生子进入分析,其中82对为（47.7%）同卵双生子（MZ）,90对为异卵双生子（DZ）。Apgar评分与MZ、DZ组CD4＋T细胞相对计数呈弱正相关（rMZ=0.16,rDZ=0.14,P〈0.05）。最终选择AE模型得到1岁幼儿外周血CD4＋和CD8＋T细胞的遗传度分别为61.8%（95%CI：38.3%-74.8%）与57.3%（95%CI：34.5%-70.2%）。结论 1岁幼儿外周血CD4＋和CD8＋T细胞亚群遗传度高于成人水平,Apgar评分或与CD4＋和CD8＋T细胞亚群相对计数相关。     

人肺癌NCI-H446细胞生成肿瘤干细胞球

目的 探索人肺癌NCI-H446细胞系干细胞球体的培养,并鉴定其生物学特性.方法 用无血清培养基培养人肺癌NCI-H446细胞得到肿瘤细胞球.将肿瘤细胞球传代扩增,并用含血清培养基培养促使其分化;四甲基偶氮唑盐(MTT)比色检测肿瘤球和普通NCI-H446细胞的增殖能力,并将肿瘤球和普通NCI-H446细胞分别植入裸鼠皮下,观察肿瘤形成;Transwell侵袭实验检测肿瘤球和普通NCI-H446细胞的侵袭能力的不同;流式细胞术检测CD133、CD44在肿瘤球和普通NCI-H446细胞中的表达,并筛选细胞表面标志物.结果 在无血清培养基中,人肺癌NCI-H446细胞可以形成少量的肿瘤细胞球,并显示很强的自我更新和增殖能力,在含血清环境中能够诱导肿瘤球分化而贴壁生长;在动物实验中,接种5×105个细胞时,肿瘤球细胞较普通NCI-H446细胞显示更强的致瘤能力;在侵袭实验中,肿瘤球细胞的侵袭能力高于普通NCI-H446细胞;干细胞标志物CD133及CD44在肿瘤球细胞的表达较普通NCI-H446细胞明显增高.结论 人肺癌细胞NCI-H446中存在癌干细胞,且可以通过无血清培养、分离和富集.     

Isolation and identification of cancer stem-like cells from murine melanoma cell lines

In current study, cancer stem-like cells in the murine melanoma B16F10 cells were investigated. CD phenotypes of the B16F10 cells were analyzed by flow cytometry, and the specific CD phenotype cells from the B16F10 cells were isolated by MACS. Then we used colony formation assay in soft agar media, the cell growth assay in serum-free culture media as well as the tumorigenicity investigation of the specific CD phenotype cells in C57BL/6 mice, respectively, to identify cancer stem-like cells in the B16F10 cells. The results showed that the B16F10 cells could form spherical clones in serum-free culture media, and the rate of clonegenesis of CD133^＋, CD44^＋ and CD44^＋CD133^＋ cells was higher than that of CD133^-, CD44^- and CD44^＋CD133^＋ cells in soft agar media, respectively. The tumorigenic potential of CD133^＋, CD44^＋, CD44^＋CD133^＋ cells and CD44^＋CD133^＋CD24^＋ cells was stronger than that of CD133^-, CD44^-, CD44^＋CD133^- cells and CD44^＋CD133^＋CD24^- cells in mice, respectively. In conclusion, the CD44^＋CD133^＋CD24^＋ cells have some biological properties of cancer stem-like cells or are highly similar to the characteristics of cancer stem cells （CSC）. These results provide an important method for identifying cancer stem-like cells in B16F10 cells and for further cancer target therapy. Cellular ＆ Molecular Immunology.     

A possible interplay between HR-HPV and stemness in tumor development: an in vivo investigation of CD133 as a putative marker of cancer stem cell in HPV18-infected KB cell line

High-risk HPVs (HR-HPVs) are DNA viruses considered as primary etiologic factors in malignancies of the low female genital tract. Their presence has also been documented in oropharyngeal and laryngeal cancers. However, HPV infection is considered a necessary but not sufficient cause of tumoral development; meantime, increasing evidences on the tumorigenic role of cancer stem cells (CSCs) have been documented in the literature. CSCs represent a small subpopulation of neoplastic cells with self-renewal potential, capable of maintaining tumor growth and cell differentiation, also involved in metastatic process, recurrence, and resistance to chemotherapeutic agents. In the present study, performed on KB cell lines, we evaluated the tumor forming potential of CSCs, and their relationship with the HPV infection status. We started our study by identifying the most aggressive cell line on the minimal number of cells being able of growth in vivo in a model of athymic nude mice (BALB/c nu/nu). We used an oral-derived KB cell line separated in the KB-CD133+ and KB-CD133- populations, by using immunomagnetic beads and fluorescence-activated cell sorting (FACS). The separated populations were injected in athymic nude mice (BALB/c nu/nu). Xenograft tumors have been analyzed for tumor size, CD133 expression by immunohistochemistry (IHC) and for DNA HR-HPV integration by in situ hybridization (ISH), comparing CD133-enriched xenograft tumors versus the CD133 non-enriched ones. On standard conditions, the KB cell line has a poor population of glycosylated CD133 marker (<5.0%) when investigated with antibodies versus CD133, and more specifically its glycosylated epitope (AC133). Enriched CD133 KB cells possess a higher capacity of tumor growth in xenograft models of nude mice when compared to KB CD133-negative cells. We observed that the AC133 epitope, extensively used to purifying hematopoietic stem cells, is able to select an epithelial subpopulation of cancer stem cells with aggressive behavior. We retain that CD133 may be a useful target in anticancer strategies including pharmacological and immunological therapies.     

Cancerous and non-neoplastic stem cells in the stomach similarly express CD44 and CD133

CD44 and CD133 have been considered as cancer stem cell (CSC) markers. Stem cell markers are rarely described in healthy stomach tissues. However, the clinicopathological and prognostic value of CD44 and CD133 in gastric cancer remains controversial. This study investigated the expression of CD44 and CD133 in gastric cancer and non-neoplastic gastric mucosa. We used samples of primary gastric adenocarcinomas (n = 69), metastatic lymph nodes (n = 30), intestinal metaplasia (n = 17), and histologically normal gastric tissues of surgical margins (n = 54). The expression of CD44 and CD133 were studied in samples by immunohistochemistry. Fisher’s exact test and a logistic regression model were used in this study. CD44 expression was observed in 12% of samples with intestinal metaplasia, 20% with lymph node metastases, 22% with normal mucosa, to 30% of samples with primary tumors. Most of these positive tumors showed immunostaining in less than 4% of cancerous cells, mainly in the diffuse type. CD133 expression was observed in 7% (intestinal metaplasia) to 46% (normal mucosa). In the positive cases of cancer (24%), in most of them, less than 3% of cells were marked. CD44 and CD133 expression in the histologically normal gastric mucosa was restricted to the deeper regions of the gastric crypts at the level where stem cells and progenitor cells are usually found. CD44 and CD133 expression occurs in few gastric cancer cells, mainly in diffuse carcinomas, and are expressed in histologically normal gastric mucosae. None of the markers are specific for cancer and are also present in intestinal metaplasia and the normal mucosa.     

小鼠髓母细胞瘤干细胞分离培养及干细胞标记物的分析

目的 旨在建立自发髓母细胞瘤模型小鼠肿瘤干细胞分离培养方法,观察其在体外形成克隆的能力,对可能的肿瘤干细胞标志分子CD44、CD133和CD15进行流式细胞术分析鉴定.方法 将小鼠髓母细胞瘤组织通过温和消化液消化分离成单细胞悬液,于干细胞培养基中培养.计算其细胞球形成率.于含血清培养基中培养观察分化能力.利用流式细胞术对其表面可能的干细胞表面标记分子进行分析鉴定.结果 从模型小鼠髓母细胞瘤组织中成功分离培养髓母细胞瘤原代细胞,原代细胞可形成具有高度的自我更新和增殖能力的细胞球;细胞球可在含血清培养基中贴壁分化成为神经元样细胞;干细胞表面标记分子流式细胞术分析表明髓母细胞瘤干细胞中CD44表达较高,CD133及CD15的表达无差异或者降低.结论 髓母细胞瘤肿瘤细胞中存在一定量的具有自我更新增殖能力、高表达CD44的肿瘤干细胞,并能在体外将其分离培养、连续传代及诱导发生分化.     

Genome and transcriptome profiles of CD133-positive colorectal cancer cells

Colorectal carcinomas (CRC) might be organized hierarchically and contain a subpopulation of tumorigenic, putative cancer stem cells that are CD133 positive. We studied the biological and genetic characteristics of such cells in CRC cell lines and primary tumors. Three CRC cell lines were sorted in CD133 positive and negative fractions. The respective genetic aberration profiles were studied using array comparative genomic hybridization (aCGH) and expression profiling. Tumorigenicity for each cellular population was tested by injection into nude mice. Additionally, we compared CD133+ and CD133- cells of 12 primary colorectal tumors using laser capture microdissection and aCGH. Three of five CRC cell lines displayed both CD133+ and CD133- cells, but tumorigenicity of these subfractions did not differ significantly and aCGH revealed essentially identical genomic imbalances. However, 96 genes were differentially expressed between the two populations. Array comparative genomic hybridization analysis after laser capture microdissection of CD133+ and CD133- areas in primary colorectal tumors revealed genetic differences in 7 of 12 cases. The use of cell lines for studying genomic alterations that define cancer stem cell characteristics, therefore, seems questionable. In contrast, CD133+ cells in primary cancer samples showed a unique genomic aberration profile. In conclusion, our data suggest that CD133 positivity defines a genetically distinct cellular compartment in primary CRC, which potentially includes tumor initiating cells.     

Establishment of pancreatic cancer stem cells by flow cytometry and their biological characteristics

To investigate the method of separating human pancreatic cancer stem cells by Hoechst 33342 labeled flow cytometry and to analyze the biological properties of pancreatic cancer stem cells. The human pancreatic cancer cell line PC-3 was divided into SP and non-SP cells by flow cytometry. The number of two cell clone spheres and nude mice tumor formation rates were compared by cultivating in serum-free medium; The expression of CD133, Nestin mRNA and protein was analyzed by real-time fluorescence quantitative PCR and Western blot; The expression of two cell drug resistance genes (MDR1, ABCG2, ABCA2 and MRP1) was analyzed by real time fluorescent quantitative PCR. The number of the cloned spheres in SP cells in serum-free medium was significantly higher than that of non-SP cells (P<0.05). The incidence of SP cells in the tumor of immunodeficiency nude mice was significantly higher than that of non-SP cells, and the difference was statistically significant (P<0.05). Real-time fluorescence quantitative PCR analysis showed that the expression of CD133 and Nestin mRNA in SP cells was significantly higher than those of non-SP cells, and the expression of CD133 and Nestin protein in SP cells was also significantly higher than those of non-SP cells (P<0.05). In conclusion, SP side population pancreatic cancer cells by Hoechst 33342 separation have the stem cell characteristics, higher tumor formation rate and higher drug resistance, which may be related to chemotherapy resistance.