结直肠癌肿瘤干细胞标志物的研究进展

近年来,肿瘤干细胞（CSC）学说得到越来越多的支持,识别CSC的关键就是寻找干细胞的表面特异性标志物.结直肠癌CSC的相关研究不断取得进展,文章综述了近几年发现的比较公认的干细胞标志物CD44、SOX9、ALDH1和OCT-4等的研究进展及其与结直肠癌的关系.     

结直肠肿瘤干细胞标志物的研究现状及进展

0 引言 全球结直肠癌发病率男性位于恶性肿瘤的第4位,女性位于第3位[1],具有发病率高、根治性差的特点.结直肠癌发病情况有显著的地区性差异,其中以北美、大洋洲最高,欧洲居中,亚非地区在较低水平[2].我国与世界发达国家相比,结直肠癌发病率和死亡率曾处于较低水平,但近年来,随着人们生活水平的提高和饮食习惯西方化的改变,结直肠癌发病率和死亡率呈现逐年上升的趋势.临床上结直肠癌的患者,虽然手术彻底切除了肿瘤,但仍有一部分患者术后会出现肿瘤的复发和转移,因此,Reya等[3]提出肿瘤的复发和转移可能是由少量存在的肿瘤干细胞不断增殖而形成的,传统的治疗方法只能抑制肿瘤的生长,不能彻底地杀死肿瘤细胞,治疗后残存一定数量的肿瘤细胞,仍可在一段时间形成肿瘤的复发和转移.     

结直肠肿瘤干细胞标志物的研究现状及进展北大核心CSCD

0引言全球结直肠癌发病率男性位于恶性肿瘤的第4位,女性位于第3位[1],具有发病率高、根治性差的特点。结直肠癌发病情况有显著的地区性差异,其中以北美、大洋洲最高,欧洲居中,亚非地区在较低水平[2]。我国与世界发达国家相比,结直肠癌发病率和死亡率曾处于较低水平,但近年来,随着人们生活水平的提高和饮食习惯西方化的改变,     

肿瘤干细胞标志物在结直肠癌中的研究进展

肿瘤干细胞(CSC)标志物是用来标记并鉴定CSC的一类分子.目前研究发现与结直肠癌有关的CSC标志物主要有CD133、CD29、CD166、CD44、Nanog等.这些干细胞标志物通过多种分子机制参与肿瘤的发生发展,可作为潜在的治疗靶点,还可被用作评估患者预后的有效指标.     

结直肠癌组织中肿瘤干细胞标志物CD44与周期蛋白p27关系及意义

目的：了解结直肠癌组织中CD44、p27表达的关系。方法：采用组织芯片检测、免疫组织化学和双重免疫组织化学染色技术检测61例结直肠癌组织中CD44、p27的表达。结果：在结直肠癌组织中,CD44与p27蛋白的表达与病理分级无明显相关性,CD44＋细胞数约占癌细胞数的0.1%-55%（30.9±19.29）,p27^＋细胞数约占癌细胞数0.1%-35%（20.9±12.21）,p27蛋白在癌组织中表达强弱不一,强阳性细胞（p27high）呈灶性或单个散在分布,约占癌细胞总数的0.1%-15%,CD44^＋细胞大多数p27^-（90%以上）,p27＋的癌细胞也极少表达CD44,CD44^＋/p27high占CD44＋细胞数的0.1%-5%（3.12±1.18）。结论：周期蛋白p27,G0/G1期（即静止期）细胞核含量最高。本实验证实只有极少数CD44＋细胞呈p27蛋白强阳性（p27high）,CD44^＋/p27high的细胞多处于静止期,可能为肿瘤干细胞,p27分子可作为进一步筛选肿瘤干细胞的一个重要标记物。     

结直肠癌组织中肿瘤干细胞标志物CD44与周期蛋白p27关系及意义

目的:了解结直肠癌组织中CD44、p27表达的关系。方法:采用组织芯片检测、免疫组织化学和双重免疫组织化学染色技术检测61例结直肠癌组织中CD44、p27的表达。结果:在结直肠癌组织中,CD44与p27蛋白的表达与病理分级无明显相关性,CD44+细胞数约占癌细胞数的0.1%-55%(30.9±19.29),p27+细胞数约占癌细胞数0.1%-35%(20.9±12.21),p27蛋白在癌组织中表达强弱不一,强阳性细胞(p27high)呈灶性或单个散在分布,约占癌细胞总数的0.1%-15%,CD44+细胞大多数p27-(90%以上),p27+的癌细胞也极少表达CD44,CD44+/p27high占CD44+细胞数的0.1%-5%(3.12±1.18)。结论:周期蛋白p27,G0/G1期(即静止期)细胞核含量最高。本实验证实只有极少数CD44+细胞呈p27蛋白强阳性(p27high),CD44+/p27high的细胞多处于静止期,可能为肿瘤干细胞,p27分子可作为进一步筛选肿瘤干细胞的一个重要标记物。     

血清肿瘤标志物对结直肠癌诊断的评价

癌胚抗原(CEA)、癌相关糖抗原(CA19-9)和(CA-50)血清标志物均为非特异的肿瘤相关抗原。近年来肿瘤相关标志物已广泛应用于肿瘤临床诊断，但各报道结果并非一致，我们对我院部分手术治疗的结、直肠癌患者术前血清CEA、CA19-9、CA-50、甲胎蛋白(AFP)和血清铁蛋白(SF)的联合检测结果进……     

结直肠癌干细胞及靶向治疗研究进展

肿瘤干细胞是一类未分化的原始肿瘤细胞,是肿瘤转移,复发和耐药的根源。研究结直肠癌干细胞及标志物对于寻求针对肿瘤干细胞的治疗措施将是肿瘤治疗研究的新方向,针对性的靶向治疗将成为肿瘤治疗的研究热点。     

CD133作为肿瘤干细胞标志物的研究进展

正1 CD133的结构和功能人CD133(AC133或者prominin-1)是一个由865个氨基酸组成的蛋白,其结构中包含一个细胞外区的N-端、5个跨膜结构域、两个细胞外loop环、一个59个氨基酸的细胞内C-端和8个N-糖基化区。CD133预测大小为97 kDa,但实际的糖基化CD133的分子量为120 kDa。CD133基因(PROM1)在所有动物中都是保     

流式细胞术检测结直肠癌根治术前后循环肿瘤细胞和循环肿瘤干细胞及其临床预测价值

目的:探讨流式细胞仪检测结直肠癌根治术前后循环肿瘤细胞(circulating tumor cell,CTC)和循环肿瘤干细胞(circulating tumor stem cell,CTSC)作为患者临床预测指标的可行性和临床价值.方法:人组首诊初治50例结直肠癌患者,手术前后各抽取15 ml外周血.分离单个核细胞后分成两份,一份标记CTC标志物(CD45、EpCAM和CK),另一份标记CTSC标志物(CD45、EpCAM、CD44和CD133),Moflo XDP流式细胞仪对其进行检测,CD45-EpCAM+ CK+细胞确定为CTC;CTSC确定为3群:CD44+CTSC、CD133+ CTSC和CD44+ CD133+ CTSC.结果:结直肠癌根治术前患者CTC和CD44+ CTSC阳性率分别为34％和44％,CD133+ CTSC和CD44+CD133+ CTSC是24％和0;术后患者CTC和CD44+ CTSC阳性率分别为38％和54％,CD133+ CTSC和CD44+ CD133+ CTSC分别为26％和0.根治术前后CTC阳性率都与肿瘤T分期有关联(P＜0.05);术后CTC与肿瘤的浸润深度、淋巴结转移和远处转移有关联(P＜0.05);术前CD44+ CTSC与肿瘤的浸润深度有关联.结论:根治术前后CTC及术前CD44+ CTSC阳性率都具有临床预测指标的可行性和价值,术后CTC阳性率可能是更好的预测指标.     

BRACHYURY confers cancer stem cell characteristics on colorectal cancer cells

Cancer stem cells (CSCs) are initiating cells in colorectal cancer (CRC). Colorectal tumours undergo epithelial to mesenchymal transition (EMT)-like processes at the invasive front, enabling invasion and metastasis, and recent studies have linked this process to the acquisition of stem cell-like properties. It is of fundamental importance to understand the molecular events leading to the establishment of cancer initiating cells and how these mechanisms relate to cellular transitions during tumourigenesis. We use an in vitro system to recapitulate changes in CRC cells at the invasive front (mesenchymal-like cells) and central mass (epithelial-like cells) of tumours. We show that the mesoderm inducer BRACHYURY is expressed in a subpopulation of CRC cells that resemble invasive front mesenchymal-like cells, where it acts to impose characteristics of CSCs in a fully reversible manner, suggesting reversible formation and modulation of such cells. BRACHYURY, itself regulated by the oncogene β-catenin, influences NANOG and other 'stemness' markers including a panel of markers defining CRC-CSC whose presence has been linked to poor patient prognosis. Similar regulation of NANOG through BRACHYURY was observed in other cells lines, suggesting this might be a pathway common to cancer cells undergoing mesenchymal transition. We suggest that BRACHYURY may regulate NANOG in mesenchymal-like CRC cells to impose a 'plastic-state', allowing competence of cells to respond to signals prompting invasion or metastasis.     

卵巢癌干细胞标记物的研究进展

卵巢癌是致命的妇科癌症之一。虽然目前的治疗策略相对有效,但存在易复发及化疗耐药,其与卵巢癌干细胞有着密切的联系。肿瘤干细胞（CSC）是肿瘤内罕见的化疗耐药性细胞,其可以用更多分化的子细胞填充大部分肿瘤,并可能导致复发性疾病。目前,对卵巢癌干细胞的分离与鉴定已经开展了很多研究,并分析了卵巢癌干细胞特异性标记物的特性。本文旨在对卵巢癌干细胞标记物的相关研究以及其作为治疗靶点的潜力进行综述。     

肿瘤干细胞标志物与胃癌关系的研究进展

肿瘤干细胞（cancer stem cell,CSCs）是理论认为肿瘤中存在一小部分细胞具有自我更新和多向分化的潜能,具有特异性表面标志的细胞.目前已经从乳腺癌、结直肠癌、皮肤癌等多种恶性肿瘤中鉴定分离出了各自的肿瘤干细胞标志物.本文就与胃癌相关的干细胞标志物进行综述.     

Up-regulation of stem cell markers by P21-activated kinase 1 contributes to 5-fluorouracil resistance of colorectal cancer

Cancer stem cells (CSC) are tumorigenic and resistant to chemotherapy. In colorectal cancer (CRC), CSCs have been identified by the expression of specific markers, including CD44, Bmi1 and Nanog. Although p21-activated kinase 1 (PAK1), acting downstream of Ras, stimulates Wnt/β-catenin signaling and is known to play an important role in CRC development and progression, the role of PAK1 in the expression of CSC markers has not previously been investigated. The effect of PAK1 over-expression, knockdown or inhibition on the expression or alteration (in the case of CD44) of CSC markers in human CRC cell lines was measured by immunofluorescence and Western blotting. The effect of PAK1 modulation on tumorigenesis, and on resistance to treatment with 5-fluorouracil (5-FU), was measured by sphere formation in vitro and by growth of xenografted tumors in vivo. The results show that PAK1 activity correlated with the expression of CSC markers and the CD44 isoform profile, and with tumor growth both in vitro and in vivo. Furthermore PAK overexpression partially overcame the inhibition of CRC growth by 5-FU, and PAK inhibition was synergistic with 5-FU treatment. Our findings lay the foundation for a combination therapy in which PAK1 inhibitors targeting CSCs may be combined with conventional 5-FU-based chemotherapy for the treatment of CRC.     

大肠癌细胞HCT-15肿瘤干细胞样细胞分离及成瘤性比较

目的:依据人大肠癌细胞HCT-15的表面标志物,分离其中的干细胞亚群。建立裸鼠体内原代大肠癌荷瘤模型,比较各亚群肿瘤体积和质量。方法:利用免疫磁珠分选技术,分离其中CD133/CD44干细胞亚群。分选得到CD133+CD44+、CD133+CD44-亚群分别接种于裸鼠体内,并观察肿瘤大小和质量。结果:CD133+CD44+和CD133+CD44-细胞亚群成功的从HCT-15细胞中分离出来。接种CD133+CD44+细胞的裸鼠形成的肿瘤体积［（2.76±0.22）cm3］和质量［（5.2±0.21）g］明显高于接种CD133+CD44-细胞裸鼠的肿瘤体积与质量［（1.56±0.34）cm3,（3.4±0.18）g］（P＜0.05）。结论:CD44阳性的大肠癌肿瘤干细胞成瘤能力明显高于CD44阴性的大肠癌肿瘤干细胞。     

与食管癌相关的癌症干细胞膜标志物的研究进展

食管癌发病率和死亡率在癌症中均位于前列。食管癌预后较差,尽管目前治疗手段不断进步,也是难治疗和治愈的恶性肿瘤之一。当前,针对食管肿瘤遗传学改变方面的研究正在逐步进行,包括分子机制、基因表达及肿瘤干细胞等的研究。本文就与食管癌相关的癌症干细胞膜标志物的研究进展作一综述。     

Cancer stem cell marker expression and methylation status in patients with colorectal cancer

The number of individuals diagnosed with colorectal cancer (CRC) has been on an alarming upward trajectory over the past decade. In some countries, this cancer represents one of the most frequently diagnosed types of neoplasia. Therefore, it is an important demand to study the pathology underlying this disease to gain insights into the mechanism of resistance to treatment. Resistance of tumors to chemotherapy and tumor aggressiveness have been associated with a minor population of neoplastic cells, which are considered to be responsible for tumor recurrence. These types of neoplastic cells are known as cancer stem cells, which have been previously reported to serve an important role in pathogenesis of this malignant disease. Slovakia has one of the highest incidence rates of CRC worldwide. In the present study, the aim was to classify the abundance of selected stem cell markers (CD133, CD166 and Lgr5) in CRC tumors using flow cytometry. In addition, the methylation status of selected genomic regions of CRC biomarkers (ADAMTS16, MGMT, PROM1 (CD133), LGR5 and ALCAM) was investigated by pyrosequencing in a cohort of patients from Martin University Hospital, Martin, Slovakia. Samples from both primary tumors and metastatic tumors were tested. Analysis of DNA methylation in the genomic regions of indicated five CRC biomarkers was also performed, which revealed the highest levels of methylation in the A disintegrin and metalloproteinase with thrombospondin motifs 16 and O6-methyguanine-DNA methyl transferase genes, whereas the lowest levels of methylation were found in genes expressing prominin-1, leucine-rich repeat-containing G-protein-coupled receptor 5 and activated leukocyte cell adhesion molecule. Furthermore, tumor tissues from metastases showed significantly higher levels of CD133⁺ cells compared with that in primary tumors. Higher levels of CD133⁺ cells correlated with TNM stage and the invasiveness of CRC into the lymphatic system. Although relatively small number of samples was processed, CD133 marker was consider to be important marker in pathology of CRC.     

Prognostic impact of the expression of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and ALDH1 in colorectal cancer

Background:

The aim of this study was to elucidate the prognostic impact of putative cancer stem cell markers CD133, CD166, CD44s, EpCAM, and aldehyde dehydrogenase-1 (ALDH1) in colorectal cancer.

Methods:

A tissue microarray of 1420 primary colorectal cancers and 57 normal mucosa samples was immunostained for CD133, CD166, CD44s, EpCAM, and ALDH1 in addition to 101 corresponding whole tissue sections. Invasive potential of three colorectal cancer cell lines was tested.

Results:

Differences between normal tissue and cancer were observed for all markers (P<0.001). Loss of membranous CD166 and CD44s were linked to higher pT (P=0.002, P=0.014), pN (P=0.004, P=0.002), an infiltrating growth pattern (P<0.001, P=0.002), and worse survival (P=0.015, P=0.019) in univariate analysis only. Loss of membranous EpCAM expression was also linked to higher pN (P=0.023) and infiltrating growth pattern (P=0.005). The CD44s, CD166, and EpCAM expression were lost towards the invasive front. The CD44−/CD166− cells from three colorectal cancer cell lines exhibited significantly higher invasive potential in vitro than their positive counterparts.

Conclusions:

Loss, rather than overexpression, of membranous CD44s, CD166, and EpCAM is linked to tumour progression. This supports the notion that the membranous evaluation of these proteins assessed by immunohistochemistry may be representative of their cell adhesion rather than their intra-cellular functions.