阿霉素通过Wnt/β-catenin信号通路抑制口腔鳞癌干细胞迁移和侵袭

目的:探讨阿霉素对口腔鳞癌干细胞迁移、侵袭、凋亡的影响及其可能的机制。方法:体外培养人口腔鳞癌细胞系SCC25,通过流式细胞术分选CD44^-和CD44⁺细胞,RT-PCR检测CD44^-和CD44⁺细胞的Oct4、CD133、CD44和GAPDH的m RNA表达;检测和比较CD44^-和CD44⁺细胞的克隆形成能力。CD44+细胞用阿霉素或β-catenin抑制剂LF3进行处理,分别使用Transwell和细胞划痕检测细胞侵袭和迁移能力,一步法TUNEL检测细胞凋亡水平,WB检测β-catenin和TCF-4的蛋白表达。结果:流式细胞术成功分离CD44^-和CD44⁺细胞,RT-PCR检测CD44+细胞高表达Oct4、CD133和CD44 m RNA,CD44-细胞弱表达Oct4m RNA,不表达CD133和CD44 m RNA;CD44⁺细胞的克隆形成能力显示显著强于CD44^-细胞(P<0.05)。阿霉素显著降低了CD44⁺细胞的侵袭能力和迁移能力(P<0.05),显著提高了CD44+细胞的凋亡率(P<0.05);阿霉素显著降低了CD44+细胞β-catenin和TCF-4的蛋白表达(P<0.05),LF3对β-catenin和TCF-4蛋白表达的影响与阿霉素比较无显著差异(P>0.05)。结论:阿霉素可能通过抑制Wnt/β-catenin信号通路降低口腔鳞癌干细胞迁移、侵袭能力,促进细胞凋亡。     

急性淋巴细胞白血病CD34+CD38-细胞在NOD/SCID小鼠体内的自我更新与增值能力

目的 探索急性淋巴细胞白血病(ALL)患者CD34+ CD38-细胞移植到NOD/SCID小鼠体内建立白血病的可行性、自我更新与增殖潜能.方法 分选并鉴定ALL患者骨髓CD34+ CD38-细胞及对照CD34- CD38+细胞后,经尾静脉分别注射104个细胞于亚致死剂量射线照射的NOD/SCID小鼠体内,连续监测小鼠状态以及外周血血象改变,对濒死或死亡小鼠进行骨髓检查、肝脾病理学检查.结果 接种从ALL患者分选的CD34+ CD38-细胞到NOD/SCID小鼠体内后4周,小鼠外周血白细胞上升,到8周左右达高峰,约15×109～20× 109/L,原始及幼稚淋巴细胞明显增多.骨髓象显示以原始及幼稚淋巴细胞增生为主,约为40％,且肝脾组织也有白细胞浸润,明显高于接种了对照组CD34- CD38+细胞的NOD/SCID小鼠.结论 ALL患者CD34+CD38-细胞可以成功移植NOD/SCID 小鼠,在小鼠体内增殖形成白血病,说明该群细胞具有自我更新和增殖的潜能,可作为探索白血病起始细胞研究的重要载体.     

急性淋巴细胞白血病CD34~+ CD38~-细胞在NOD/SCID小鼠体内的自我更新与增殖能力

目的探索急性淋巴细胞白血病(ALL)患者CD34+CD38-细胞移植到NOD/SCID小鼠体内建立白血病的可行性、自我更新与增殖潜能。方法分选并鉴定ALL患者骨髓CD34+CD38-细胞及对照CD34-CD38+细胞后,经尾静脉分别注射104个细胞于亚致死剂量射线照射的NOD/SCID小鼠体内,连续监测小鼠状态以及外周血血象改变,对濒死或死亡小鼠进行骨髓检查、肝脾病理学检查。结果接种从ALL患者分选的CD34+CD38-细胞到NOD/SCID小鼠体内后4周,小鼠外周血白细胞上升,到8周左右达高峰,约15×109～20×109/L,原始及幼稚淋巴细胞明显增多。骨髓象显示以原始及幼稚淋巴细胞增生为主,约为40%,且肝脾组织也有白细胞浸润,明显高于接种了对照组CD34-CD38+细胞的NOD/SCID小鼠。结论 ALL患者CD34+CD38-细胞可以成功移植NOD/SCID小鼠,在小鼠体内增殖形成白血病,说明该群细胞具有自我更新和增殖的潜能,可作为探索白血病起始细胞研究的重要载体。     

白细胞介素4降低脐带间充质干细胞对造血干细胞分化潜能的维持能力

目的探讨白细胞介素4（IL-4）对脐带间充质干细胞（UC-MSC）维持造血干细胞分化的影响。 方法将UC-MSC与脐带血CD34⁺造血干细胞按照造血支持能力常用的方案共培养,实验分为对照组和IL-4组,IL-4处理组加入IL-4（20 ng/ml）培养14 d。收集细胞并计数,使用流式细胞仪检测表达CD34的细胞比例。取3×10³个细胞,加入到半固体培养基,培养14 d后,通过倒置显微镜观察比较各种集落的形成,并使用流式细胞仪分析其中巨噬细胞和粒细胞表面特异性蛋白CD11b、CD14和CD15的表达。对两独立样本进行t检验统计学分析。 结果加入IL-4后,共培养体系中细胞数量（1.31±0.05）×10⁵个/孔与对照组（2.80±0.28）×10^5?个/孔相比下降,差异有统计学意义（t = 7.31,P < 0.05）,并且流式细胞分析显示其中的CD34⁺细胞比例也有降低。3×10³个IL-4组得到的细胞形成巨噬细胞集落形成单位的能力（9.33±1.53）?个/孔较对照组（17.67±0.58）个/孔有明显下降,差异有统计学意义（t = 8.84,P?< 0.001）;形成粒-巨噬集落形成单位的能力（15.67±3.22）个/孔较对照组（29.33±4.04）?个/?孔有明显下降,差异有统计学意义（t = 4.58,P < 0.05）;形成总集落单位的能力（39.33±9.07）个/?孔较对照组（62.67±6.66）?个/?孔也有下降,差异有统计学意义（t = 3.59,P < 0.05）。IL-4组得到的细胞分化出的细胞总数（3.67±1.71）×10⁵个/孔与对照组（9.50± 3.13）×10⁵个/孔相比也明显下降,差异有统计学意义（t = 2.83,P < 0.05）,而流式细胞术分析发现分化成的细胞中CD14⁺细胞比例也下降。 结论IL-4可以降低UC-MSC对造血干细胞分化潜能的维持能力,提示在Ⅱ型辅助T细胞相关体液免疫疾病中使用间充质干细胞治疗时,也需要兼顾机体造血相关功能。     

亲缘供者外周血红细胞参数对造血干细胞采集影响的经验分析

目的探讨亲缘供者外周血红细胞参数对COBE Spectra血细胞分离机的自动外周血干细胞采集程序（AutoPBSC程序）与单个核细胞采集程序（MNC程序）的影响及经验分析。 方法选取河北燕达陆道培医院2019年6月至2021年2月小红细胞亲缘供者31例45次采集为小红细胞组,选取同期非小红细胞亲缘供者51例60次采集为非小红细胞组,分别应用AutoPBSC程序和MNC程序,比较两组采集情况及采集产品相关指标。采用独立样本t检验和Mann-Whitney U检验分析2组计量资料的差异。 结果与小红细胞AutoPBSC程序组比较,小红细胞MNC程序组血小板（PLT）降低率[（25.88±15.83）﹪比（36.64±10.22）﹪]、采集效率[32.65﹪（23.60﹪,73.82﹪）比63.74﹪ （59.83﹪,68.55﹪）]、采集物体积[（158.83±34.39）比（222.91±63.9）mL]、MNC总数[（218.04±117.57）×10⁸/L比（350.24±127.64）×10⁸/L]、CD34⁺细胞总数[113.83×10⁶/L （79.25×10⁶/L,154.10×10⁶/L）比233.26×10⁶/L （177.18×10⁶/L,392.51×10⁶/L）]、MNC计数[（4.04±2.61）×10⁸/kg比（5.54±2.22）×10⁸/ kg]、CD34⁺计数[1.84×10⁶/kg （1.16×10⁶/kg,4.41×10⁶/kg）比3.64×10⁶/kg （2.49×10⁶/kg,6.37×10⁶/kg）]均升高,差异有统计学意义（P < 0.05）;与非小红细胞AutoPBSC程序组比较,非小红细胞组MNC程序组采集物体积[（162.83±51.74）比（242.56±43.25）mL]升高,差异有统计学意义（P < 0.05）。 结论对造血干细胞移植供者红细胞体积偏小时,应用MNC程序采集外周血造血干细胞,比应用AutoPBSC程序更有优势。     

人脐血CD34+细胞在NOD/SCID小鼠免疫重建及其抗HBV作用的初步探讨

目的：探讨NOD／SCID（nonobese diabetic／severe combined immunodeficient）小鼠移植人脐带血（human umbilical cord blood,HUCB）CD34＋细胞后免疫重建的特性。建立hu—NOD／SCID人鼠嵌合模型并观察其人源化免疫细胞在小鼠体内的生长分化特性、存活时间及其对HBV感染的清除作用。方法：1．NOD／SCID小鼠于C0603．5Gy照射后24h内尾静脉输注HUCBCD34＋细胞;2．以流式细胞技术鉴定小鼠外周血中CD45＋,CD3＋,CD19＋,CD56＋等人源化细胞的比例;3．NOD／SCID小鼠于移植后第4wk注射HBV感染者血清并以未移植的NOD／SCID小鼠作为对照,注射同等量的患者血清;4．于感染后1、7、10、15天采血,免疫荧光定量PCR方法分别检测其HBV—DNA含量。结果：1．HUCBCD34＋细胞移植后第2wk,在小鼠外周血中检测出的CD3＋CD8＋T细胞、CD3＋CD4＋T细胞、CD19＋B细胞、CD56＋NK细胞的比例分别为18．6％、16．1％、13．1％和27．8％。各细胞比例随小鼠周龄而变化。所有移植小鼠存活时间均达9wk;2．移植后小鼠感染HBV血清后,病毒仅在感染后第一天检出,随后消失;未移植CD34＋细胞的小鼠外周血HBV—DNA一直维持在103水平：结论：1．NOD／SCID小鼠经射线照射后移植HUCBCD34＋细胞,在不加任何刺激因子的情况下小鼠可以长时间存活并重建免疫;2．hu—NOD／SCID人鼠嵌合模型小鼠免疫成功重建后,对HBV感染有快速的清除作用。     

肝素促进脐血巨核祖细胞体外扩增

目的 :探索肝素在脐带血CD34⁺ 细胞定向扩增巨核祖细胞中的作用。方法采用免疫磁珠法 (MACS)分选CD34⁺ 细胞 ,在TPO ,IL 1 1的扩增体系中加入肝素 ,巨核祖细胞集落分析 (CFU MK)测定巨核祖细胞扩增倍数 ,流式细胞仪检测巨核祖细胞分化过程中的特异性标记 (CD34⁺ ,CD41a⁺ ,CD61⁺ ,CD34⁺ CD41a⁺ ,CD41a⁺ CD61 ⁺ ) ,巨核细胞特异性抗体 (CD41a)免疫组化染色和透射电镜观察鉴定巨核细胞形态及超微结构 ,血小板体外活化实验及NOD/SCID小鼠异种体内移植实验评价扩增的巨核祖细胞的功能。结果 :TPO( 5 0ng/ml)与IL-1 1 ( 5 0ng/ml)双因子联合应用 ,7天巨核祖细胞克隆扩增倍数为 83 1 7± 39 41倍 ,1 0天为 2 0 5 0 6± 74 2 6倍 ,流式细胞仪分析显示 7天CD34⁺ CD41a+ 细胞扩增 1 0 5 1± 4 79倍 ,0天加入肝素后 ,7天巨核祖细胞克隆扩增倍数为 1 0 8 2 5± 32 67倍 ,1 0天为 333 0 6± 2 7 5 4倍 ,7天CD34⁺ CD41a⁺ 细胞扩增到 2 9 93± 6 39倍 ,为无肝素组的 2.85倍 ,与双因子组相比有统计学差异 (P <0.0 1 ) ,肝素在第 5天及第 7天加入没有增加巨核祖细胞扩增效果。经全身照射预处理的NOD/SCID小鼠静脉输注扩增第 7天的巨核细胞 (TPO、IL-11、肝素联合 ) ,可明显加速其血小板及白细胞计数的恢复并提高生存率 ;同时 ,体外血小板活化实验证实扩增的巨核细胞在体外可产生血小板 ,有正常巨核细胞功能。结论 :TPO、IL-11组合的扩增体系中加入肝素可进一步改善脐带血巨核祖细胞的扩增效果 ,优化体外扩增体系。     

胃癌SGC-7901细胞株侧群细胞分选及生物学特性的初步研究

目的:分选胃癌细胞株中的侧群(side population,SP)细胞并初步研究其相关生物学特性。方法:选择人胃癌细胞株SGC-7901,以荧光染料Hoechst 33342染色,维拉帕米拮抗对照,应用流式细胞仪检测并分选出SP细胞和nonSP细胞。CCK-8法观察两组细胞体外增殖活性;体外耐药实验检测两组细胞对化疗药物5-FU的耐药存活率;无血清培养基培养观察肿瘤球形成能力;荧光定量PCR检测干细胞相关基因Musashi-1和CD44在两组细胞中的表达差异;裸鼠体内成瘤实验观察两组细胞体内成瘤能力。 结果:胃癌细胞株SGC-7901中SP细胞的比例为2.8%,与nonSP细胞相比,SP细胞具有较强的体外增殖活性(P<0.05),对5-FU的耐药存活率明显高于nonSP细胞(P<0.05),在无血清培养基中能形成明显的肿瘤球,SP细胞中Musashi-1和CD44mRNA的相对表达量明显高于nonSP细胞(P<0.05),裸鼠体内成瘤实验表明,皮下注射2×10³ 个SP细胞就能形成肿瘤,而2×10⁴ 个nonSP细胞也不能形成肿瘤。 结论:胃癌细胞株SGC-7901中存在数量极少的SP细胞,SP细胞具有肿瘤干细胞的相关生物学特性。     

GATA1s敲除hPSCs模型构建与造血分化影响初探

本文建立了GATA1s敲除人多能干细胞(human pluripotent stem cells,hPSCs)细胞株，并以此为模型探讨了GATA1s缺失对体外诱导造血分化的影响。本文通过构建含有重组臂-敲入片段(GATA1外显子Ⅱ-Ⅵ序列及BGH polyA序列)-LoxP-潮霉素筛选标记-LoxP-重组臂的打靶质粒和含有gRNA-Cas9的gRNA质粒对hPSCs进行基因编辑以敲除GATA1s。通过第一步电穿孔将以上质粒导入细胞，潮霉素初步筛选7 d后的阳性克隆进行下一步电穿孔环化重组酶(Cre)使LoxP位点特异性重组以去除筛选标记，通过单细胞克隆的方式进一步培养，PCR及测序鉴定出正确基因编辑细胞，最后通过蛋白质免疫印迹验证其GATA1与GATA1s蛋白的表达情况，验证敲除GATA1s后的细胞株进行体外诱导造血分化，发现其CD34⁺、CD43⁺及CD45⁺细胞增多，但GPA⁺、CD41a⁺及CD42b⁺细胞显著减少，通过转座子系统过表达GATA1也不...     

长非编码RNA HOTAIR调控胃癌细胞SGC-7901来源肿瘤干细胞样细胞

肿瘤干细胞样细胞具有自我更新、无限增殖和多向分化能力,且受到长非编码RNA（long non-coding RNAs, lncRNAs）的调控。长非编码RNA HOTAIR在人胃癌细胞中表达升高,且具有调控功能。但目前对其在胃癌干细胞样细胞中的功能尚无研究。本研究的目的是探讨胃癌肿瘤干细胞中HOTAIR对肿瘤恶性行为的调控作用。本研究采用无血清培养基在补充细胞因子条件下培养SGC-7901细胞,获得悬浮生长的肿瘤干细胞样细胞微球,检测微球细胞的表面特征因子CD44、CD24及HOTAIR的表达量变化;并通过CCK-8、流式细胞分析及ELISA等技术探讨了HOTAIR对肿瘤干细胞样细胞功能调控作用。结果表明,无血清培养基中获得的肿瘤干细胞样细胞具有自我更新能力,其可连续传代细胞微球的比率为4.75%±0.76%;RT-qPCR检测显示,相对于SGC-7901细胞,肿瘤干细胞样细胞中的HOTAIR表达量明显升高;通过慢病毒干扰技术发现,HOTAIR干扰抑制了HLA-G蛋白分泌、促进肿瘤干细胞样细胞的细胞周期推进、细胞增殖和自我更新能力维持。本研究提示,胃癌细胞系SGC-7901中的肿瘤干细胞样细胞中HOTAIR表达量升高,并可能通过促进肿瘤干细胞样细胞干性调控肿瘤恶性行为。     

Isolation of Stem Cells from Human Pancreatic Cancer Xenografts

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal and produce differentiated progeny¹. These properties allow CSCs to recapitulate the original tumor when injected into immunocompromised mice. CSCs within an epithelial malignancy were first described in breast cancer and found to display specific cell surface antigen expression (CD44⁺CD24^low/-)². Since then, CSCs have been identified in an increasing number of other human malignancies using CD44 and CD24 as well as a number of other surface antigens. Physiologic properties, including aldehyde dehydrogenase (ALDH) activity, have also been used to isolate CSCs from malignant tissues^3-5.Recently, we and others identified CSCs from pancreatic adenocarcinoma based on ALDH activity and the expression of the cell surface antigens CD44 and CD24, and CD133^6-8. These highly tumorigenic populations may or may not be overlapping and display other functions. We found that ALDH⁺ and CD44⁺CD24⁺ pancreatic CSCs are similarly tumorigenic, but ALDH⁺ cells are relatively more invasive⁸. In this protocol we describe a method to isolate viable pancreatic CSCs from low-passage human xenografts⁹. Xenografted tumors are harvested from mice and made into a single-cell suspension. Tissue debris and dead cells are separated from live cells and then stained using antibodies against CD44 and CD24 and using the ALDEFLUOR reagent, a fluorescent substrate of ALDH¹⁰. CSCs are then isolated by fluorescence activated cell sorting. Isolated CSCs can then be used for analytical or functional assays requiring viable cells.     

Identification and Characterization of Cells with Cancer Stem Cell Properties in Human Primary Lung Cancer Cell Lines

Lung cancer (LC) with its different subtypes is generally known as a therapy resistant cancer with the highest morbidity rate worldwide. Therapy resistance of a tumor is thought to be related to cancer stem cells (CSCs) within the tumors. There have been indications that the lung cancer is propagated and maintained by a small population of CSCs. To study this question we established a panel of 15 primary lung cancer cell lines (PLCCLs) from 20 fresh primary tumors using a robust serum-free culture system. We subsequently focused on identification of lung CSCs by studying these cell lines derived from 4 representative lung cancer subtypes such as small cell lung cancer (SCLC), large cell carcinoma (LCC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). We identified a small population of cells strongly positive for CD44 (CD44^high) and a main population which was either weakly positive or negative for CD44 (CD44^low/−). Co-expression of CD90 further narrowed down the putative stem cell population in PLCCLs from SCLC and LCC as spheroid-forming cells were mainly found within the CD44^highCD90⁺ sub-population. Moreover, these CD44^highCD90⁺ cells revealed mesenchymal morphology, increased expression of mesenchymal markers N-Cadherin and Vimentin, increased mRNA levels of the embryonic stem cell related genes Nanog and Oct4 and increased resistance to irradiation compared to other sub-populations studied, suggesting the CD44^highCD90⁺ population a good candidate for the lung CSCs. Both CD44^highCD90⁺ and CD44^highCD90⁻ cells in the PLCCL derived from SCC formed spheroids, whereas the CD44^low/− cells were lacking this potential. These results indicate that CD44^highCD90⁺ sub-population may represent CSCs in SCLC and LCC, whereas in SCC lung cancer subtype, CSC potentials were found within the CD44^high sub-population.     

CD44 and CD24 cannot act as cancer stem cell markers in human lung adenocarcinoma cell line A549

Cancer stem cells (CSCs) are subpopulations of tumor cells that are responsible for tumor initiation, maintenance and metastasis. Recent studies suggested that lung cancer arises from CSCs. In this study, the expression of potential CSC markers in cell line A549 was evaluated. We applied flow cytometry to assess the expression of putative stem cell markers, including aldehyde dehydrogenase 1 (ALDH1), CD24, CD44, CD133 and ABCG2. Cells were then sorted according to the expression of CD44 and CD24 markers by fluorescence-activated cell sorting (FACS) Aria II and characterized using their clonogenic and sphere-forming capacity. A549 cells expressed the CSC markers CD44 and CD24 at 68.16% and 54.46%, respectively. The expression of the putative CSC marker ALDH1 was 4.20%, whereas the expression of ABCG2 and CD133 was 0.93%. Double-positive CD44/133 populations were rare. CD44⁺/24⁺ and CD44⁺/CD24^?/low subpopulations respectively exhibited 64% and 27.92% expression. The colony-forming potentials in the CD44⁺/CD24⁺ and CD44⁺/CD24^?/low subpopulations were 84.37 ± 2.86% and 90 ± 3.06%, respectively, while the parental A549 cells yielded 56.65 ± 2.33% using the colony-formation assay. Both isolated subpopulations formed spheres in serumfree medium supplemented with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF). CD44 and CD24 cannot be considered potential markers for isolating lung CSCs in cell line A549, but further investigation using in vivo assays is required.     

CD44~+CD24~(-/low)与ALDH1~+作为乳腺癌干细胞标志物之异同

越来越多的研究表明,CD44+CD24-/low与ALDH1+都是乳腺癌干细胞标志物。CD44+CD24-/low细胞与ALDH1+细胞具有很多相同的性质,但又有不同的性质和特点。该文主要就CD44+CD24-/low与ALDH1+之间的相同点、两者在乳腺癌干细胞特性方面的差异及其与乳腺癌基因亚型、预后、转移和耐药之间的不同关系等方面作一综述。     

CAFs外泌体通过上调ABCB5诱导乳腺癌细胞化疗耐药

目的:探讨肿瘤相关成纤维细胞(CAFs)诱导乳腺癌细胞耐药及其作用机制。方法:从临床样本中分离培养CAFs,获取条件培养基,并纯化外泌体。使用CAFs条件培养基或CAFs外泌体与CD44+的乳腺癌干细胞(CSCs)和CD44-的非干细胞亚群共培养,并用5氟尿嘧啶(5-FU)处理共培养的细胞,通过成球实验和CCK8实验检测细胞的自我更新能力和存活能力。抑制细胞中ABCB5的表达,检测5-FU对细胞存活能力的影响。结果:CAFs条件培养或外泌体处理的CSCs自我更新能力和对5-FU的耐药能力更强,成球能力和对5-FU耐药性上升约1.5-2倍。CAFs外泌体可提高CSCs中ABCB5的表达水平约4-5倍,抑制ABCB5可降低CSCs的耐药性至原来的约60-80%。结论:CAFs通过旁分泌外泌体增强CSCs的自我更新能力并通过上调CSCs中ABCB5的表达水平促进其对化疗药物的抵抗。     

Non-small cell lung cancer stem/progenitor cells are enriched in multiple distinct phenotypic subpopulations and exhibit plasticity

Cancer stem cells (CSCs) represent a population of cancer cells that possess unique self-renewal and differentiation characteristics required for tumorigenesis and are resistant to chemotherapy-induced apoptosis. Lung CSCs can be enriched by several markers including drug-resistant side population (SP), CD133^pos and ALDH^high. Using human non-small cell lung adenocarcinoma cell lines and patient-derived primary tumor cells, we demonstrate that SP cells represent a subpopulation distinct from other cancer stem/progenitor cell (CS/PC) populations marked by CD133^pos or ALDH^high. The non-CS/PCs and CS/PCs of each subpopulation are interconvertible. Epithelial-mesenchymal transition (EMT) promotes the formation of CD133^pos and ALDH^high CS/PC subpopulations while suppressing the SP CS/PC subpopulation. Rac1 GTPase activity is significantly increased in cells that have undergone EMT, and targeting Rac1 is effective in inhibiting the dynamic conversion of non-CS/PCs to CS/PCs, as well as the CS/PC activity. These results imply that various subpopulations of CS/PCs and non-CS/PCs may achieve a stochastic equilibrium in a defined microenvironment, and eliminating multiple subpopulations of CS/PCs and effectively blocking non-CS/PC to CS/PC transition, by an approach such as targeting Rac1, can be a more effective therapy.     

A CD44high/EGFRlow Subpopulation within Head and Neck Cancer Cell Lines Shows an Epithelial-Mesenchymal Transition Phenotype and Resistance to Treatment

Mortality in head and neck squamous cell carcinoma (HNSCC) is high due to emergence of therapy resistance which results in local and regional recurrences that may have their origin in resistant cancer stem cells (CSCs) or cells with an epithelial-mesenchymal transition (EMT) phenotype. In the present study, we investigate the possibility of using the cell surface expression of CD44 and epidermal growth factor receptor (EGFR), both of which have been used as stem cell markers, to identify subpopulations within HNSCC cell lines that differ with respect to phenotype and treatment sensitivity. Three subpopulations, consisting of CD44^high/EGFR^low, CD44^high/EGFR^high and CD44^low cells, respectively, were collected by fluorescence-activated cell sorting. The CD44^high/EGFR^low population showed a spindle-shaped EMT-like morphology, while the CD44^low population was dominated by cobblestone-shaped cells. The CD44^high/EGFR^low population was enriched with cells in G0/G1 and showed a relatively low proliferation rate and a high plating efficiency. Using a real time PCR array, 27 genes, of which 14 were related to an EMT phenotype and two with stemness, were found to be differentially expressed in CD44^high/EGFR^low cells in comparison to CD44^low cells. Moreover, CD44^high/EGFR^low cells showed a low sensitivity to radiation, cisplatin, cetuximab and gefitinib, and a high sensitivity to dasatinib relative to its CD44^high/EGFR^high and CD44^low counterparts. In conclusion, our results show that the combination of CD44 (high) and EGFR (low) cell surface expression can be used to identify a treatment resistant subpopulation with an EMT phenotype in HNSCC cell lines.     

Effect of Melatonin in Epithelial Mesenchymal Transition Markers and Invasive Properties of Breast Cancer Stem Cells of Canine and Human Cell Lines

Cancer stem cells (CSCs) have been associated with metastasis and therapeutic resistance and can be generated via epithelial mesenchymal transition (EMT). Some studies suggest that the hormone melatonin acts in CSCs and may participate in the inhibition of the EMT. The objectives of this study were to evaluate the formation of mammospheres from the canine and human breast cancer cell lines, CMT-U229 and MCF-7, and the effects of melatonin treatment on the modulation of stem cell and EMT molecular markers: OCT4, E-cadherin, N-cadherin and vimentin, as well as on cell viability and invasiveness of the cells from mammospheres. The CMT-U229 and MCF-7 cell lines were subjected to three-dimensional culture in special medium for stem cells. The phenotype of mammospheres was first evaluated by flow cytometry (CD44⁺/CD24^low/- marking). Cell viability was measured by MTT colorimetric assay and the expression of the proteins OCT4, E-cadherin, N-cadherin and vimentin was evaluated by immunofluorescence and quantified by optical densitometry. The analysis of cell migration and invasion was performed in Boyden Chamber. Flow cytometry proved the stem cell phenotype with CD44⁺/CD24^low/- positive marking for both cell lines. Cell viability of CMT-U229 and MCF-7 cells was reduced after treatment with 1mM melatonin for 24 h (P<0.05). Immunofluorescence staining showed increased E-cadherin expression (P<0.05) and decreased expression of OCT4, N-cadherin and vimentin (P<0.05) in both cell lines after treatment with 1 mM melatonin for 24 hours. Moreover, treatment with melatonin was able to reduce cell migration and invasion in both cell lines when compared to control group (P<0.05). Our results demonstrate that melatonin shows an inhibitory role in the viability and invasiveness of breast cancer mammospheres as well as in modulating the expression of proteins related to EMT in breast CSCs, suggesting its potential anti-metastatic role in canine and human breast cancer cell lines.     

Cancer stem cell marker‐expressing cell‐rich spheroid fabrication from PANC‐1 cells using alginate microcapsules with spherical cavities templated by gelatin microparticles

Cancer stem‐like cells (CSCs) are rare subpopulations of cancer cells. The development of three‐dimensional tissues abundant in CSCs is important to both the understanding and establishment of novel therapeutics targeting them. Here, we describe the fabrication of multicellular tumor spheroids (MTSs) abundant in CSCs by employing alginate microcapsules with spherical cavities templated by cell‐enclosing gelatin microparticles. Encapsulated human pancreatic cancer cell line PANC‐1 cells grew for 14 days until they filled the cavities. The percentage of cells expressing reported CSC markers CD24, CD44, and epithelial‐specific antigen (ESA), increased during this growth period. The percentage at 24 days of incubation, 22%, was 1.6 times higher than that of MTSs formed on a nonadherent surface in the same period of incubation. The MTSs in microcapsules could be cryopreserved in liquid nitrogen using a conventional method. No significant difference in the content of CSC marker‐expressing cells was detected at 3 days of incubation when thawed after cryopreservation for 2 weeks, compared with cells incubated without prior cryopreservation. © 2015 American Institute of Chemical Engineers Biotechnol. Prog., 31:1071–1076, 2015