循环肿瘤细胞在外周血中的存活与转移机制

肿瘤转移是恶性肿瘤发展的一个重要阶段,也是导致患者死亡的主要原因。实体恶性肿瘤病灶(原发或转移灶)的肿瘤细胞因自发性脱落或外部因素释放入血形成循环肿瘤细胞(circulating tumor cells,CTCs)。CTCs是肿瘤患者出现复发转移的最直接原因。外周血中的CTCs会因血流剪切力作用、失巢凋亡以及免疫细胞杀伤作用死亡,但仍有小部分的CTCs可以存活下来并发生转移。因此,研究CTCs在外周血中的存活转移机制对肿瘤患者的诊治具有重要意义,本文对CTCs在外周血中存活转移机制的最新研究进展进行了综述,并对其未来发展进行展望。     

循环肿瘤细胞在肿瘤治疗中的研究进展

循环肿瘤细胞(circulating tumor cells,CTCs)由原发肿瘤和转移肿瘤灶中的癌细胞播散而来,对CTCs的定量和定性检测可用于肿瘤的早期诊断、转移复发监测、药效分析和生存期预后等方面,在肿瘤预防与治疗中具有重要应用价值。CTCs在肿瘤临床中的应用是当今非常活跃的研究领域,探索新的特异性CTCs分子标志,并研发更加灵敏、高效和特异的CTCs分析新技术,也成为目前研究的热点。本文简要综述了CTCs用于肿瘤防治的研究进展。     

循环肿瘤细胞在乳腺癌预后评价中的应用和意义

循环肿瘤细胞(CTCs)是导致肿瘤转移的主要原因,它在外周血中的含量与乳腺癌的转移、治疗和预后有密切的关系.本文对于CTCs的概念、检测方法、以及作为肿瘤转移预测指标的优势进行了综述.并对其在临床上的运用前景进行了展望.     

微流控芯片技术在循环肿瘤细胞分离中的研究进展

循环肿瘤细胞(circulating tumor cells,CTCs)是指从原发肿瘤或转移灶脱落、发生上皮-间质转化进入患者外周血血液循环的恶性肿瘤细胞.CTCs在肿瘤研究和临床诊断上的作用逐渐得到认可,外周血中CTCs存在与否以及数量多少不但可以用于肿瘤的早期诊断,还可以用于评估肿瘤预后、监测肿瘤的转移和复发.微流控芯片作为一个高通量、小型化的细胞实验平台,已被应用于CTCs的分选当中.本文综述了用于CTCs捕获的微流控芯片系统的最新研究进展,着重介绍各类芯片的捕获原理、芯片结构和捕获效率,最后对微流控芯片技术在CTCs分选中的应用前景进行了展望.     

循环肿瘤细胞在40例晚期转移性乳腺癌患者中的检测意义

目的:探讨循环肿瘤细胞CTCs在晚期转移性乳腺癌中的应用价值。方法:Cell Search系统检测本院40例复发转移性乳腺癌患者的CTCs水平,比较复发转移性乳腺癌患者血液中CTCs的差异,分析复发转移性乳腺癌患者CTCs与其疾病特征及预后的关系。结果:Cell Search系统检测复发转移性乳腺癌患者外周血CTCs阳性率达42.5%;在复发转移性乳腺癌患者中,CTCs≥5个/7.5 mL者的肝脏转移、骨转移、转移灶≥3处均较CTCs5个/7.5 mL者更高(P0.05),前者的PFS较之后者也表现出强烈的缩短趋势(X2=3.573,P=0.059),而肺转移、淋巴结转移、脑转移、胸壁复发、受体及HER2表达在两组间无差异。结论:Cell Search系统展现出较好的检测复发转移性乳腺癌患者外周血CTCs的能力。在复发转移性乳腺癌患者中,CTCs的高检出率与腹腔脏器转移、肝转移、骨转移相关。CTCs≥5个/7.5 mL患者的预后很可能要差于CTCs5个/7.5 mL者。     

靶向循环肿瘤细胞治疗策略在抗肿瘤转移中的应用

转移是肿瘤治疗的主要挑战，90%的肿瘤相关死亡病例与肿瘤转移有关。循环肿瘤细胞(circulating tumor cells,CTCs)是肿瘤转移形成的关键，与肿瘤转移的形成过程密切相关。因此，靶向CTCs的治疗策略成为目前抗肿瘤转移研究的热点。基于此，本文从CTCs的产生、CTCs的播散和CTCs的远端定植三个阶段综述了CTCs参与肿瘤转移的机制，并分别从调节肿瘤转移相关基因表达和抑制EMT过程抑制肿瘤细胞脱落产生CTCs、激活自身免疫细胞和仿生细胞膜或特异性分子修饰纳米制剂在血液循环捕获消除CTCs、抑制CTCs黏附并穿过血管内皮细胞和破坏PMN处适宜肿瘤细胞生长的微环境等方面总结了控制肿瘤转移的研究进展，以期为肿瘤转移预防和治疗提供新的思路。     

循环microRNAs的外泌形成机制及其对乳腺癌侵袭和转移的影响

目前乳腺癌的临床诊疗主要依赖影像学和相对较少的预后/预测指标(如雌激素受体、孕激素受体、HER2等).这些生物标志物主要是基于原发肿瘤病灶的生物学检测,可用于转移或复发的检测指标很少,尤其是在切除肿瘤原发灶后,复发监测很困难.循环cell-free microRNAs(circulating cf-miRNAs,或简称circulating miRNAs)的发现为改变现有乳腺癌临床诊疗模式提供了可能.Cell-free miRNA通过外泌体、微囊或转运蛋白的主动外泌机制,可能在循环miRNA的形成中起着重要作用.Cell-free miRNA特别是circulating miRNA不仅自身可以作为信号分子影响肿瘤细胞和组织微环境,而且还可以与其他信号通路发生交互通讯来调控肿瘤部位新生血管的形成和肿瘤细胞表型的上皮-间质转换,影响乳腺癌的侵袭和转移.本文综述了循环miRNA的特征与分泌机制,特别是乳腺癌相关的循环miRNA参与作为一种液体活检生物标志物在乳腺癌诊断、预后评价和疗效评估的临床意义.     

乳腺癌患者循环肿瘤细胞检测的研究进展

血行播散是乳腺癌转移的重要途径,检测腋窝淋巴结已经不能完全准确判断乳腺癌患者是否存在转移。肿瘤细胞进入外周血是肿瘤远处转移的前提,对乳腺癌患者循环肿瘤细胞的检测将有助于判断预后,指导治疗,监测治疗效果。简要综述了乳腺癌循环肿瘤细胞及其检测方法的研究进展。     

乳腺癌生物标志物的研究进展

乳腺癌是一种妇女常见恶性肿瘤,90%的乳腺癌患者死亡由肿瘤的复发和转移所致。乳腺癌的发病机制尚不清楚。目前乳腺癌尚缺乏早期的高效敏感的分子标志物。筛查乳腺癌复发转移的早期分子标志物,对早期诊断乳腺癌的发生和转移、指导个性化治疗、评价生存和预后尤其重要。本文基于乳腺癌的生物学特性,分别对最热点的乳腺癌分子标志物——miRNA、CTCs、ctDNA和μPA在乳腺癌中的表达及作用,并对其在诊疗和预后方面的研究进展进行综述。     

微流控芯片在分选富集循环肿瘤细胞中的应用

循环肿瘤细胞(circulating tumor cells, CTCs)是指从原发肿瘤部位脱落,进入外周血循环的肿瘤细胞,对其准确检测有利于早期癌症转移的诊断与治疗。然而,血液中CTCs的量极少,检测前要先对其进行分选富集。在众多的分选富集方法中,微流控芯片技术成本低、通量高、样品需求量小,可达到特异、灵敏、高捕获率的效果。该文综述了近年来使用微流控芯片分选富集CTCs的方法,同时,分析了各种方法的优缺点,并对未来的发展趋势进行了探讨。     

Imaging Circulating Tumor Cells in Freely Moving Awake Small Animals Using a Miniaturized Intravital Microscope

Metastasis, the cause for 90% of cancer mortality, is a complex and poorly understood process involving the invasion of circulating tumor cells (CTCs) into blood vessels. These cells have potential prognostic value as biomarkers for early metastatic risk. But their rarity and the lack of specificity and sensitivity in measuring them render their interrogation by current techniques very challenging. How and when these cells are circulating in the blood, on their way to potentially give rise to metastasis, is a question that remains largely unanswered. In order to provide an insight into this "black box" using non-invasive imaging, we developed a novel miniature intravital microscopy (mIVM) strategy capable of real-time long-term monitoring of CTCs in awake small animals. We established an experimental 4T1-GL mouse model of metastatic breast cancer, in which tumor cells express both fluorescent and bioluminescent reporter genes to enable both single cell and whole body tumor imaging. Using mIVM, we monitored blood vessels of different diameters in awake mice in an experimental model of metastasis. Using an in-house software algorithm we developed, we demonstrated in vivo CTC enumeration and computation of CTC trajectory and speed. These data represent the first reported use we know of for a miniature mountable intravital microscopy setup for in vivo imaging of CTCs in awake animals.     

A label-free microfluidic chip for the highly selective isolation of single and cluster CTCs from breast cancer patients

BackgroundCirculating tumor cells (CTCs) existing in peripheral blood can be used to predict the prognosis and survival of cancer patients. The study was designed to detect circulating tumor cells and circulating tumor single cell genes by applying microfluidic chip technology. It was used to explore the clinical application value in breast cancer.MethodsWe have developed a size-based CTCs sorting microfluidic chip, which contains a hexagonal array and a micro-pipe channel array to isolate and confirm both single CTCs and CTCs clusters. The sorting performance of the as-fabricated chip was tested by analyzing the clinical samples collected from 129 breast cancer patients and 50 healthy persons.ResultsIn this study, the chip can detect different immunophenotypes of CTCs in breast cancer patients. It was found that the new microfluidic device had high sensitivity (73.6%) and specificity (82.0%) in detecting CTCs. By detecting the blood samples of 129 breast cancer patients and 50 healthy blood donors, it was found that the number of CTCs was not associated with clinical factors such as age, gender, pathological type, and tumor size of breast cancer patients (P > 0.05), but was associated with TNM staging of breast cancer, with or without metastasis (P < 0.005). There was a statistically significant difference in the number of CTCs between luminal A (ER+/PR+/HER2-) and HER-2+ (ER-/PR-/HER2+) (P < 0.05). The best cut-off level distinguished by CTC between the breast cancer patients and the healthy persons was 3.5 cells/mL, with 0.845 for AUC-ROC, 0.790–0.901 for 95% CI, 73.6% for sensitivity, and 82% for specificity (P = 0.000). The combination of CTC, CEA, CA125 and CA153 can provide more effective breast cancer screening.ConclusionsThe CTCs analysis method presented here doesn''t rely on the specific antibody, such as anti-EpCAM, which would avoid the missed inspection caused by antibody-relied methods and offer more comprehensive biological information for clinical breast cancer diagnosis and treatment.     

Circulating tumor cells from patients with advanced prostate and breast cancer display both epithelial and mesenchymal markers

During cancer progression, malignant cells undergo epithelial-mesenchymal transitions (EMT) and mesenchymal-epithelial transitions (MET) as part of a broad invasion and metastasis program. We previously observed MET events among lung metastases in a preclinical model of prostate adenocarcinoma that suggested a relationship between epithelial plasticity and metastatic spread. We thus sought to translate these findings into clinical evidence by examining the existence of EMT in circulating tumor cells (CTC) from patients with progressive metastatic solid tumors, with a focus on men with castration-resistant prostate cancer (CRPC) and women with metastatic breast cancer. We showed that the majority (> 80%) of these CTCs in patients with metastatic CRPC coexpress epithelial proteins such as epithelial cell adhesion molecule (EpCAM), cytokeratins (CK), and E-cadherin, with mesenchymal proteins including vimentin, N-cadherin and O-cadherin, and the stem cell marker CD133. Equally, we found that more than 75% of CTCs from women with metastatic breast cancer coexpress CK, vimentin, and N-cadherin. The existence and high frequency of these CTCs coexpressing epithelial, mesenchymal, and stem cell markers in patients with progressive metastases has important implications for the application and interpretation of approved methods to detect CTCs.     

Detection of mycoplasma infection in circulating tumor cells in patients with hepatocellular carcinoma

Many studies have shown that persistent infections of bacteria promote carcinogenesis and metastasis. Infectious agents and their products can modulate cancer progression through the induction of host inflammatory and immune responses. The presence of circulating tumor cells (CTCs) is considered as an important indicator in the metastatic cascade. We unintentionally produced a monoclonal antibody (MAb) CA27 against the mycoplasmal p37 protein in mycoplasma-infected cancer cells during the searching process of novel surface markers of CTCs. Mycoplasma-infected cells were enriched by CA27-conjugated magnetic beads in the peripheral blood mononuclear cells in patients with hepatocellular carcinoma (HCC) and analyzed by confocal microscopy with anti-CD45 and CA27 antibodies. CD45-negative and CA27-positive cells were readily detected in three out of seven patients (range 12–30/8.5 ml blood), indicating that they are mycoplasma-infected circulating epithelial cells. CA27-positive cells had larger size than CD45-positive hematological lineage cells, high nuclear to cytoplasmic ratios and irregular nuclear morphology, which identified them as CTCs. The results show for the first time the existence of mycoplasma-infected CTCs in patients with HCC and suggest a possible correlation between mycoplasma infection and the development of cancer metastasis.     

Epithelial–mesenchymal transition markers expressed in circulating tumor cells in hepatocellular carcinoma patients with different stages of disease

The presence of circulating tumor cells (CTCs) in peripheral blood is associated with metastasis and prognosis in hepatocellular carcinoma (HCC) patients. The epithelial–mesenchymal transition (EMT) has a pivotal role in tumor invasion and dissemination. To identify more sensitive biomarkers for evaluating metastasis and prognosis, we investigated the expression of EMT markers, including vimentin, twist, ZEB1, ZEB2, snail, slug and E-cadherin in CTCs, primary HCC tumors and adjacent non-tumoral liver tissues. After isolating viable CTCs from the peripheral blood of HCC patients using asialoglycoprotein receptors (ASGPRs), the CTCs were identified with immunofluorescence staining. CTCs were detected in the peripheral blood obtained from 46 of 60 (76.7%) HCC patients. Triple-immunofluorescence staining showed that twist and vimentin expression could be detected in CTCs obtained from 39 (84.8%) and 37 (80.4%) of the 46 patients, respectively. The expression of both twist and vimentin in CTCs was significantly correlated with portal vein tumor thrombus. Coexpression of twist and vimentin in CTCs could be detected in 32 (69.6%) of the 46 patients and was highly correlated with portal vein tumor thrombus, TNM classification and tumor size. Quantitative fluorescence western blot analysis revealed that the expression levels of E-cadherin, vimentin and twist in HCC tumors were significantly associated with the positivity of isolated CTCs (P=0.013, P=0.012, P=0.009, respectively). However, there was no significant difference in ZEB1, ZEB2, snail and slug expression levels in CTCs, primary HCC tumors and adjacent non-tumoral liver tissues across samples with regard to the clinicopathological parameters. Our results demonstrate that the EMT has a role in promoting the blood-borne dissemination of primary HCC cells, and the twist and vimentin expression levels in CTCs could serve as promising biomarkers for evaluating metastasis and prognosis in HCC patients.     

UHRF1基因在乳腺癌循环肿瘤细胞中的表达研究

外周血液中乳腺循环癌肿瘤细胞的生物表征与转移性乳腺癌的严重程度密切相关,本研究的目的在于结合体外细胞实验探讨UHRF1基因对乳腺癌进展的意义。多重RNA原位分析乳腺癌循环肿瘤细胞(circulating tumor cells,CTCs)中UHRF1的表达;MTT法检测UHRF1基因转染对正常乳腺细胞增殖的影响;蛋白免疫印迹检测UHRF1基因转染对正常乳腺细胞中Bax蛋白和Bcl-2蛋白的影响;Caspase-3检测试剂盒检测正常乳腺细胞中Caspase-3活性;Transwell侵袭实验和划痕愈合实验检测UHRF1基因转染对正常乳腺细胞侵袭和迁移能力的影响。研究发现,UHRF1 RNA水平在乳腺癌循环肿瘤细胞中高表达;UHRF1基因增加正常乳腺细胞增殖率;UHRF1基因降低正常乳腺细胞中Caspase-3活性;UHRF1基因降低正常乳腺细胞中Bax蛋白的表达,增加Bcl-2蛋白的表达;UHRF1基因增强正常乳腺细胞侵袭和迁移能力。本研究初步说明,UHRF1可促进正常乳腺细胞增殖,抑制正常乳腺细胞凋亡,增强正常乳腺细胞侵袭和迁移能力。     

Classification of Circulating Tumor Cells by Epithelial-Mesenchymal Transition Markers

In cancer, epithelial-mesenchymal transition (EMT) is associated with metastasis. Characterizing EMT phenotypes in circulating tumor cells (CTCs) has been challenging because epithelial marker-based methods have typically been used for the isolation and detection of CTCs from blood samples. The aim of this study was to use the optimized CanPatrol CTC enrichment technique to classify CTCs using EMT markers in different types of cancers. The first step of this technique was to isolate CTCs via a filter-based method; then, an RNA in situ hybridization (RNA-ISH) method based on the branched DNA signal amplification technology was used to classify the CTCs according to EMT markers. Our results indicated that the efficiency of tumor cell recovery with this technique was at least 80%. When compared with the non-optimized method, the new method was more sensitive and more CTCs were detected in the 5-ml blood samples. To further validate the new method, 164 blood samples from patients with liver, nasopharyngeal, breast, colon, gastric cancer, or non-small-cell lung cancer (NSCLC) were collected for CTC isolation and characterization. CTCs were detected in 107(65%) of 164 blood samples, and three CTC subpopulations were identified using EMT markers, including epithelial CTCs, biophenotypic epithelial/mesenchymal CTCs, and mesenchymal CTCs. Compared with the earlier stages of cancer, mesenchymal CTCs were more commonly found in patients in the metastatic stages of the disease in different types of cancers. Circulating tumor microemboli (CTM) with a mesenchymal phenotype were also detected in the metastatic stages of cancer. Classifying CTCs by EMT markers helps to identify the more aggressive CTC subpopulation and provides useful evidence for determining an appropriate clinical approach. This method is suitable for a broad range of carcinomas.     

Heterogeneity of ERα and ErbB2 Status in Cell Lines and Circulating Tumor Cells of Metastatic Breast Cancer Patients

Hormone therapy and anti-ErbB2 therapies are prescribed according to the hormone receptor [estrogen receptor α (ERα)/progesterone receptor] and ErbB2 status of the initial tumor, but it appears that circulating tumor cells (CTCs) and, consequently, the metastatic cells may have a different receptor status. As an attempt to meet the crucial need for identification of the subpopulation of patients that will benefit from more individualized therapies, rapidly evolving therapies should allow a profiling of the tumors and/or of the CTCs. We established a triple fluorescence staining using eight cell lines to visualize the CTCs (cytokeratin detection) and then to define their individual ERα and ErbB2 status. Afterward, we used this method for blood samples from 26 metastatic breast cancer patients. We identified major differences of ERα levels between the cell lines and even within one cell line. For the metastatic patients, we detected and characterized CTCs in 38.5% of the patients with a total of 92 CTCs. We could demonstrate that at least 69.6% of the CTCs exhibit an ERα and/or ErbB2 status different from the status of the primary tumor and that the CTCs from only 30% of the patients had no change of receptor status. Strikingly, heterogeneities of the status, aggregation, and size clearly appear within the CTCs. The data we generated outline the importance of a profiling not only of tumors but also of CTCs to establish individualized treatments. CTCs may then appear as new prognosis and treatment marker for both metastatic and adjuvant breast cancers.