上调miR-200a表达对人肝癌细胞MHCC97中边缘群细胞干细胞特性的影响

目的:探讨转染miR-200a mimics对人肝癌细胞系MHCC97中边缘群细胞(SP)干细胞特性的影响。方法:利用流式细胞技术从MHCC97细胞中分离出SP细胞。转染组为应用脂质体介导转染miR-200a mimics的SP细胞,对照组为未接受转染的SP细胞。采用实时荧光定量RT-PCR检测两组SP细胞miR-200a的表达情况。四甲基偶氮唑盐(MTT)和软琼脂克隆形成实验检测细胞增殖情况。Transwell小室检测细胞迁移能力。裸鼠成瘤实验检测细胞体外成瘤能力。结果:转染miR-200a mimics可明显上调SP细胞miR-200a的表达。MTT结果显示转染组SP细胞的增殖能力明显低于对照组(P<0.05),转染组软琼脂中克隆形成率(24.70±5.54)%明显低于对照组(51.63±7.11)%（P<0.05)。Transwell实验显示转染组细胞穿膜数为(18.52±4.27)个,明显少于对照组(63.34±7.41)个(P<0.05)。裸鼠成瘤实验中转染组成瘤数(1/8)也低于对照组(8/8)（P<0.05)。结论:上调人肝癌细胞系MHCC97中SP细胞miR-200a的表达,能够抑制SP细胞的增殖和迁移,降低体外成瘤能力,即抑制SP细胞的干细胞特性。     

CD44+CD24-/low乳腺癌干细胞分选鉴定及其多药耐药性研究

目的:观察MACS免疫磁珠法分选CD44+CD24-/low乳腺癌干细胞活性,并检测其与多药耐药的关系。方法:运用MACS免疫磁珠法从多药耐药乳腺癌细胞株MCF-7/ADR中分选CD44+CD24-/low乳腺癌干细胞,流式细胞术测定分选前后CD44+CD24-/low细胞比例,微球体培养法检测分选细胞自我更新能力,流式检测CD44+CD24-/low细胞表面P-糖蛋白(P-gp)表达水平,Real-time PCR检测多药耐药相关基因MDR1表达水平。结果:MACS免疫磁珠法分选后,CD44+CD24-/low细胞比例为93.85%,其成球能力明显强于non-CD44+CD24-/low细胞亚群。MCF-7/ADR细胞株和CD44+CD24-/low乳腺癌干细胞P-gp表达强度分别为101 177.10±2 171.86和114 906.70±2 560.19,P<0.05。CD44+CD24-/low乳腺癌干细胞MDR1基因表达水平为MCF-7/ADR细胞株的(1.07±0.02)倍,P<0.05。结论:经MACS免疫磁珠法分选所得CD44+CD24-/low细胞亚群有更强的自我更新能力,高表达P-gp蛋白和MDR1基因可能是引起乳腺癌多药耐药的重要原因。     

免疫磁珠分选与顺铂富集喉癌Hep-2细胞系中肿瘤干细胞的比较

目的比较免疫磁珠分选（MACS）及化疗药物顺铂（DDP）筛选富集喉癌Hep-2细胞系肿瘤干细胞的效果。方法以CD133MACS、DDP作用两种方法来富集喉癌Hep-2细胞系中的肿瘤干细胞,并以流式细胞术（FCM）检测处理后CD133^＋细胞的百分率。同时观察细胞形态学的改变,判断两种方法分选后细胞对后续实验的影响。结果经FCM检测,MACS分选喉癌Hep-2,CD133^＋细胞得率为64．33％,不同浓度DDP作用于喉癌Hep-2细胞48h,FCM检测CD133^＋细胞有不同的得率,其中质量浓度为4μg／ml时,所得CD133^＋≥细胞百分率最高,为50．7％。MACS与DDP各组比较差异均有统计学意义（P〈0．01）;两种方法处理后MACS组细胞的存活状态要好于DDP组。结论MACS分选纯度较高,对细胞损伤小,适合后续培养;但分选前耗时长,每次分选仅能用于一种Marker。DDP筛选简单易行,符合临床肿瘤干细胞（CSC）抵抗化疗的模式。但阳性细胞得率与细胞毒性成正比。MACS和DDP筛选肿瘤干细胞各有其优势及适用范围,实验中可根据不同目的来确定所用筛选方法。     

人肝癌组织中肿瘤干细胞样细胞的分离培养及鉴定

目的：从人肝癌组织中分离培养肝癌干细胞样细胞,为进一步研究肝癌干细胞靶向治疗奠定基础。方法：采用酶消化法和以原代培养结合短暂传代培养的方法从人肝癌组织中分离出含人肝癌干细胞样细胞（human liver cancer stemlike cells, hLCSLCs) 的连续传代细胞,分别加入肝素、白蛋白、氢化可的松以筛选适用于hLCSLCs的无血清悬浮成球培养基。以流式细胞术检测hLCSLCs和由无血清悬浮成球培养所获得的成球细胞中旁群（side population, SP）细胞、CD133及CD90等的表达,裸鼠成瘤实验检测这两种细胞的致瘤能力。结果：成功地从人肝癌组织分离获得hLCSLCs,其SP、CD133+和CD90+细胞含量分别为0.9%、0.8%和12.7%,裸鼠皮下接种2 000个SP细胞的成瘤率为100%。含有肝素的无血清培养基更适于hLCSLCs的成球培养,所获成球细胞中SP、CD133+和CD90+细胞含量分别为4.6%、9.7%和48%,接种10 000个成球细胞即可全部成瘤。结论：成功建立了从人肝癌组织中分离肿瘤干细胞样细胞的方法,添加肝素的无血清悬浮成球培养法可有效富集肝癌干细胞样细胞。     

肝癌干细胞的研究进展

我国是原发性肝癌高发的国家,其发病率、死亡率约占全球的一半以上。尽管目前肝癌的诊断和治疗有了许多新的进展,但是总体疗效仍不满意。近年来的研究表明,肝癌中存在着一群具有干细胞特征、能自我更新、自我无限增殖并具有多向分化潜能的细胞,即肝癌干细胞,这对重新认识肝癌的发生、发展、预后转归以及指导临床治疗将起到极为重要的作用。本文通过复习肝癌干细胞相关文献,就肝癌干细胞起源、分选及相关治疗的研究进展作一综述。     

高转移潜能肝癌HCCLM3细胞中侧群细胞的分离及其干细胞特性鉴定

目的:检测高转移潜能肝癌HCCLM3细胞株中侧群(side population,SP)细胞比例,分选SP细胞并探讨其生物学特性。方法:4种肝癌细胞株的转移潜能大小依次为HCCLM3>MHCC97H>MHCC97L>Huh7,分别予以荧光染料Hoechst33342染色,以加入维拉帕米的拮抗组为对照,流式细胞术检测SP细胞比例;从HCCLM3细胞中分选SP细胞和主群(main population,MP)细胞,采用悬浮球培养、Transwell侵袭实验及裸鼠成瘤实验判断HCCLM3 SP细胞是否具备肿瘤干细胞生物学特性;RT-PCR检测SP及MP细胞中干细胞相关基因的表达。结果:HCCLM3细胞中SP细胞比例为(16.9±1.8)%,显著多于MHCC97H、MHCC97L、Huh7中SP细胞比例[(8.4±0.7)%、(4.6±0.5)%、(1.0±0.2)%,均P<0.05]。HCCLM3细胞中,SP细胞悬浮球形成明显高于MP细胞[(25.3±5.1)%vs(11.2±2.6)%,P<0.05],SP细胞的侵袭能力显著高于MP细胞(P<0.05),SP细胞的裸鼠皮下成瘤能力也明显高于MP细胞。HCCLM3细胞的SP细胞中干细胞相关基因ABCG2、CD13、CD44、Nanog、Sox2及Klf4 mRNA平均表达水平分别是MP细胞的5.64、2.26、2.10、3.78、2.37、2.92倍(均P<0.05)。结论:肝癌HCCLM3细胞的SP细胞中富集了肝癌干细胞,这可能与其较高的转移潜能有关。     

吉西他滨联合YH-16对肝癌干细胞样细胞的影响

目的：探讨吉西他滨联合重组人血管内皮抑制素YH-16对裸鼠CD133+MHCC97H肝癌移植瘤中肝癌干细胞样细胞的影响。方法：用免疫磁珠分选MHCC97H中肝癌干细胞样细胞,将其接种到20只裸鼠皮下,建立移植瘤模型。治疗组给予吉西他滨和YH-16,对照组给予等量生理盐水,比较两组移植瘤大小变化及原代培养细胞球形成情况,流式细胞术检测原代培养中CD133+细胞百分率。结果：治疗组的移植瘤明显缩小,治疗组和对照组细胞球形成数目分别为(7.5±2.4)个 vs (16.0±3.5)个,细胞球直径分别为(178.30±19.21) μm vs (131.06±20.96) μm（P＜0.05）;治疗组和对照组原代培养中CD133+细胞百分数分别为（6.24±0.96）% vs（18.26±1.76）%（P＜0.05）。结论：低剂量吉西他滨联合YH-16可抑制血管内皮细胞破坏肝癌干细胞样细胞的血管巢,进而选择性清除肝癌干细胞样细胞。     

小细胞肺癌干细胞样细胞的分离鉴定

背景与目的:小细胞肺癌是高度侵袭的恶性肿瘤,患者的5年生存率不足10%,提示小细胞肺癌组织中可能富含较多的肿瘤干细胞.本研究设计从小细胞肺癌组织中原代培养肿瘤细胞并建立细胞系,从早期传代的细胞系中分离鉴定肺癌干细胞.方法:用无血清培养基原代培养肺癌细胞,传代后建立细胞系.应用流式细胞分析及分选技术,从细胞系第3代或第4代的细胞中寻找肺癌干细胞.应用单细胞克隆形成实验、平板集落形成试验及细胞球形成实验,研究肺癌干细胞的生物学特性.结果:应用原代细胞培养技术成功地从1例小细胞肺癌标本中培养出高纯度的原代肺癌细胞,其传代次数可达25代以上.流式细胞学分析显示该细胞系中有5.1%的细胞CD44呈强阳性表达(CD44++),相比于占主群的CD44弱阳性细胞(CD44+),CD44++细胞具有较强的平板集落形成能力,只有它们可以形成完全克隆(holoclone),在超低黏附的96孔培养板中可形成细胞球,而CD44+细胞不能形成完全克隆和细胞球.这些结果提示小细胞肺癌干细胞富集在CD44++细胞群中,而CD44+细胞中没有干细胞.应用CD44和CD90共同标记,可将小细胞肺癌细胞系中的细胞分为4群,分别是CD44+CD90-、CD44+CD90+、CD44++CD90-和CD44++CD90+细胞,其中CD44++CD90+细胞所占比例为1.9%.相比于其他细胞群,CD44++CD90+细胞形成细胞球的能力最强,提示CD90可能也是肺癌的干细胞标记.结论:小细胞肺癌细胞系中存在肿瘤干细胞样细胞,CD44和CD90可能是小细胞肺癌的干细胞标记.     

人前列腺癌细胞系DU 145中肿瘤干细胞样侧群细胞的分离

目的:分离人前列腺癌细胞系DU 145中的侧群(side population,SP)细胞,并初步分析其生物学特性。方法:采用荧光激活细胞分类(fluorescence activated cell sorting,FACS)技术,从DU 145细胞中分离出侧群细胞,并检测其比例;继而培养于无血清培养基中,观察其生长特性。采用反转录聚合酶链反应(RT-PCR)技术检测侧群细胞中ABCG2的表达水平。结果:DU 1 4 5细胞中存在含量极少的侧群细胞,比例约1.1%;培养于无血清培养基中成簇生长。和对应的母系DU 145细胞相比,DU 145侧群细胞的ABCG2表达增高。结论:人前列腺癌细胞系DU 145中存在具有肿瘤干细胞特性的侧群细胞。     

肝细胞癌的诱导分化治疗

肝细胞癌是最常见的恶性肿瘤之一,虽然其诊断和治疗有不少进展,但其预后仍较差,病死率较高。诱导分化治疗这一概念的提出为肝细胞癌的治疗指明了新的方向。诱导分化治疗在血液系统肿瘤治疗方面获得了成功,其经典范例是全反式维甲酸临床治疗急性早幼粒白血病;但是其在恶性实体肿瘤领域的进展远不如血液系统肿瘤。目前特异性的肝细胞癌诱导分化剂较少,相关的临床应用更是有限。靶向性地针对肿瘤干细胞分化相关的信号转导通路或转录因子进行干预可能起到诱导肝细胞癌分化的效果,例如通过上调与肝细胞分化密切相关的转录因子肝细胞核因子4α（hepatocyte nuclear factor 4α, HNF4α)来诱导肝癌细胞,特别是诱导肝癌干细胞向成熟阶段分化,已初见成效。肿瘤发生发展过程中存在诸多表观遗传学异常改变,如甲基化、乙酰化水平异常或microRNA表达异常,有些改变与肿瘤分化密切相关,干预这些异常改变的药物如组蛋白去乙酰化酶抑制剂对肿瘤起到一定的诱导分化作用。因此,肿瘤干细胞学说的出现及表现遗传学的发展给肝细胞癌诱导分化治疗研究提供了具体的途径。     

肝星状细胞条件培养基对肝癌细胞PLC/PRF/5耐药性的影响及其机制

目的：探讨肝星状细胞条件培养基（hepatic stellate cell conditioned medium,HSC-CM）对人肝癌PLC/PRF/5细胞耐药性的影响及其可能的机制。 方法： 用无血清RPMI 1640培养肝星状细胞LX-2,使其在缺营养的环境下活化,收集其条件培养上清即为HSC-CM。PLC/PRF/5细胞在HSC-CM条件下培养24 h后,顺铂处理12 h或24 h,采用流式细胞术检测PLC/PRF/5细胞的凋亡情况,MTT法检测PLC/PRF/5细胞的增殖,real-time PCR检测PLC/PRF/5细胞上皮间质转化（epithelial mesenchymal transition,EMT）相关基因的表达水平。 结果： 顺铂组12和24 h两个时间点PLC/PRF/5细胞的凋亡率为（22.34±1.12）%和（26.78±1.56）%;HSC-CM+顺铂组细胞的凋亡率为（17.22±1.42）%和（21.52±1.76）%,顺铂组细胞凋亡率显著高于HSC-CM+顺铂组（P<0.05）。同在这两个时间点,顺铂组和HSC-CM+顺铂组PLC/PRF/5细胞的增殖活性分别为（68.65±2.56）%和（79.47±1.43）%,（46.54±3.65）%和（62.77±2.89）%,HSC-CM+顺铂组细胞增殖活性均高于顺铂组（P<0.05）。Real-time PCR 结果显示,与顺铂组相比较,HSC-CM+顺铂组PLC/PRF/5细胞中上皮标记物钙黏蛋白（E-cadherin）的表达下降（P<0.05）,而间质细胞标记物神经黏附素（N-cadherin）、波形蛋白（vimentin）以及EMT相关转录因 子Snail和ZEB1的表达显著上调（P<0.01）。 结论: HSC-CM可能通过诱导PLC/PRF/5细胞发生EMT,从而增强PLC/PRF/5 细胞对顺铂的抵抗作用。     

肝细胞癌起源的研究

肝细胞癌是临床常见的难治的恶性肿瘤之一,发病率逐年升高。大量证据表明肝脏干细胞在肝癌的发生发展中起重要作用。有两个关于肝癌干细胞关键问题值得回答：肝细胞癌是否来源于肝干细胞？肝细胞癌是否有肿瘤干细胞的特点？然而到目前为止,肝癌的干细胞仍未被分离,且可靠的表面标志仍未被确认。     

miR-214/199a/199a* cluster levels predict poor survival in hepatocellular carcinoma through interference with cell-cycle regulators

Aims

To identify the clinical and functional association of miR-214/199a/199a* cluster in human hepatocellular carcinoma (HCC) and to clarify the mechanism of miR-214.

Methods

Kaplan-Meier and Cox proportional regression analyses were used to determine the association of miR-214/199a/199a* cluster levels with the survival of HCC patients. The role of miR-214 in regulating HCC cell proliferation was studied with miR-214 mimics/inhibitor-treated cells. Furthermore, the inhibition effect of miR-214 on E2F2, cyclin-dependent kinase (CDK) 3 and CDK6 expression was assessed in HCC cell lines with miR-214 mimics/inhibitors to increase/decrease miR-214 expression. Direct binding of miR-214 to the 3′-untranslated regions of E2F2, CDK3, and CDK6 was verified by dual-luciferase reporter assay.

Results

In analyzing HCC clinical specimens and cell lines, we discovered a uniform decrease in miR-214/199a/199a* expression in comparison with noncancerous tissue or normal liver epithelial cell lines. Higher miR-214 levels were related with improved patient survival. Overexpression of miR-214 in HCC cells inhibited proliferation by inducing G1-S checkpoint arrest. Conversely, RNA interference–mediated silencing of miR-214 promoted cell-cycle progression and accelerated the proliferation of HCC cells. E2F2, CDK3 and CDK6 were each directly targeted for inhibition by miR-214, and restoring their expression reversed miR-214 inhibition of cell-cycle progression. The relationship between expression of miR-214 and its targets was confirmed in HCC tumor xenografts and clinical specimens.

Conclusions

Our results demonstrate that miR-214 has tumor-suppressive activity in HCC through inhibition of E2F2, CDK3 and CDK6.     

miRNA-7/21/107 contribute to HBx-induced hepatocellular carcinoma progression through suppression of maspin

Maspin suppresses tumor progression by promoting cell adhesion and apoptosis and by inhibiting cell motility. However, its role in tumorigenesis of hepatocellular carcinoma (HCC) remains unclear. The gene regulation of maspin and its relationship with HCC patient prognosis were investigated in this study. Maspin expression was specifically reduced in HBV-associated patients and correlated with their poor prognosis. Maspin downregulation in HCC cells was induced by HBx to promote their motility and resistance to anoikis and chemotherapy. HBx-dependent induction of microRNA-7, -107, and -21 was further demonstrated to directly target maspin mRNA, leading to its protein downregulation. Higher expressions of these microRNAs also correlated with maspin downregulation in HBV-associated patients, and were associated with their poor overall survival. These data not only provided new insights into the molecular mechanisms of maspin deficiency by HBx, but also indicated that downregulation of maspin by microRNAs confers HBx-mediated aggressiveness and chemoresistance in HCC.     

ALDH1A1-overexpressing cells are differentiated cells but not cancer stem or progenitor cells in human hepatocellular carcinoma

Aldehyde dehydrogenase 1A1 (ALDH1A1) is considered to be a cancer stem cell marker in several human malignancies. However, the role of ALDH1A1 in hepatocellular carcinoma (HCC) has not been well elucidated. In this study, we investigated the relationship between ALDH1A1 and clinicopathological findings and examined whether ALDH1A1 deserves to be a cancer stem cell marker in HCC. Sixty HCC samples obtained from surgical resection were collected for immunohistochemical (IHC) staining. Of these 60 samples, 47 samples of HCC tumorous and non-tumorous tissues were evaluated with qRT-PCR. There was no significant difference in the ALDH1A1-mRNA level between tumorous and non-tumorous tissues. Tumorous ALDH1A1-mRNA level had no relationship with the clinicopathological features. Immunoreactivity of ALDH1A1 was classified into two groups based on the percentage of ALDH1A1-overexpressing cells. The ALDH1A1-high group was significantly associated with low serum levels of α-fetoprotein, small tumor diameter, very little lymphovascular invasion, more differentiated pathology and good stage. The ALDH1A1-high group showed more favorable prognosis for recurrence-free survival. In double-staining IHC, ALDH1A1 was not co-expressed with BMI1, EpCAM, CD13, CD24, CD90 and CD133, which reported as cancer stem cell markers in HCC. In conclusion, ALDH1A1-overexpressing cells could appear to be differentiated cells rather than cancer stem cells in HCC.     

肝细胞性肝癌组织CD133+细胞肿瘤干细胞特性的研究

目的 越来越多的研究表明,肝癌细胞系中能检测到肿瘤干细胞(cancer stem cells,CSCs)的存在.本研究旨在探讨从肝细胞性肝癌(hepatocellular carcinoma,HCC)组织样本中分离获得的CD133+细胞是否具有CSCs特性.方法 将2014-02-01-2015-06-30广西医科大学附属肿瘤医院肝胆外科25例手术获得的新鲜HCC组织和对应癌旁组织,采用酶消化法分别消化成单个肝癌细胞和单个肝细胞,利用流式细胞术检测部分单个肝癌细胞和单个肝细胞CD133的表达率.用剩余的单个肝癌细胞进行原代培养,流式细胞术将培养获得的肝癌细胞分选为CD133+和CD133-细胞,通过平板克隆形成实验、肿瘤球形成实验和裸鼠移植瘤形成实验对比分析这两组细胞的CSCs特性.结果 25例HCC组织中CD133的表达率为3.8％～8.3％,平均值为(5.8±1.6)％,而癌旁组织CD133的表达率为0.1％～0.4％,平均值为(0.2±0.1)％,两者比较差异有统计学意义,t=17.12,P＜0.001.CD133+和CD133-细胞的平均克隆率分别为(25.2±0.8)％和(7.6±0.8)％,两者比较差异有统计学意义,t=81.95,P＜0.001.CD133+和CD133-细胞的平均成球率分别为(20.3±0.6)％和(12.5±1.4)％,两者比较差异有统计学意义,t=68.17,P＜0.001.CD133+细胞的裸鼠移植瘤形成能力明显高于CD133-细胞.结论 从HCC组织样本中分离获得的CD133+细胞具有明显的CSCs特性.     

Diagnostic and prognostic implications of microRNAs in human hepatocellular carcinoma

MicroRNAs (miRNAs) are important gene regulators, which are often deregulated in cancers. In this study, the authors analyzed the microRNAs profiles of 78 matched cancer/noncanerous liver tissues from HCC patients and 10 normal liver tissues and found that 69 miRNAs were differentially expressed between hepatocellular carcinoma (HCC) and corresponding noncancerous liver tissues (N). Then the expressions of 8 differentially expressed miRNAs were validated by real time RT PCR. The set of differentially expressed miRNAs could distinctly classify HCC, N and normal liver tissues (NL). Moreover, some of these differentially expressed miRNAs were related to the clinical factors of HCC patients. Most importantly, Kaplan-Meier estimates and the log-rank test showed that high expression of hsa-miR-125b was correlated with good survival of HCC patients (hazard ratio, 1.787, 95% confidence interval, 1.020-3.133, p = 0.043). The transfection assay showed that overexpression of miR-125b in HCC cell line could obviously suppress the cell growth and phosporylation of Akt. In conclusion, the authors have demonstrated the diagnostic miRNA profile for HCC, and for the first time, identified the miR-125b with predictive significance for HCC prognosis.     

Capturing circulating tumor cells of hepatocellular carcinoma

Early metastases of hepatocellular carcinoma (HCC) may be detected by the isolation of circulating tumor cells (CTCs) in the bloodstream. During the course of therapeutic attempts, monitoring CTC changes in patients with HCC is helpful for the efficacy assessment. Nevertheless, the markers used for the detection, such as α-feto protein, asialoglycoprotein receptor or epithelial cell adhesion molecule, CD133 or CD90, are not specific for HCC CTCs. In spite of these limitations, a timely determination of the existence of CTCs will be beneficial for the monitoring of distant metastases, the evaluation of therapeutic attempts, and the prediction of prognosis.