循环肿瘤细胞在肝癌中的应用进展

肝癌在恶性肿瘤死亡顺位中仅次于胃癌、食道癌而居第三位〔1〕。尽管针对肝癌已有诸多治疗措施,但由于大多数患者诊断延迟,发现时已达中晚期,导致肝癌患者治疗后的预后较差,而根本原因即是肿瘤的复发与转移〔2〕。目前所能发现的肿瘤转移灶大多数是通过计算机断层扫描(CT)、磁共振成像(MRI)或正电子发射计算机断层显像(PET-CT)等影像检测手段,但此时往往进入了肿瘤晚期。循环肿瘤细胞(CTCs)是指由原发肿瘤或转移灶通过血管侵犯而侵入癌症患者外周血液中的肿瘤细胞〔3〕。早在1869年,Ashworth就在1例乳腺癌患者尸检过程中发现了外周血中存在肿瘤细胞,随着近年来分子生物学及检测技术的发展,CTCs成为肿瘤早期转移及治疗术后复发领域研究的热点〔4,5〕。已知,CTCs在乳腺癌、肺癌、前列腺癌及结直肠癌复发及预后的预测中起着重要作用,但其在肝癌中的研究应用还远不及这些肿瘤类型。本文着重探讨肝癌CTCs的检测及其对肝癌复发及转移的预测作用。     

DNA甲基化在胰腺癌早期诊断及治疗中的研究进展

胰腺癌(pancreatic cancer, PC)是恶性程度最高的消化道系统肿瘤之一,多数患者就诊时已属中晚期从而失去根治性手术机会,导致5年生存率不到5%. PC患者外周血中循环肿瘤DNA浓度明显高于正常健康人群,并且携带有肿瘤特有的基因突变与甲基化改变.DNA甲基化是表观遗传学的重要表现形式,也是肿瘤发生中的早期事件,早于基因突变并且可以出现在PC进展的各个阶段.因此, PC患者启动子区异常DNA甲基化的检测可能为肿瘤的早期诊断、预后评价以及复发监测提供了一种简便的、无创的有效方法.本文就近年来人们对于DNA甲基化在PC早期诊断中的研究进展及其对于PC治疗的潜在价值进行综述.     

循环肿瘤细胞在食管癌和胃癌中的表达及临床意义的研究进展

循环肿瘤细胞是一种重要的肿瘤标志物,对循环肿瘤细胞的检测是近年来肿瘤液体活检的研究热点。食管癌和胃癌都属于高发病率和高病死率的肿瘤,对循环肿瘤细胞数量的动态监测对判断二者早期转移、化疗效果及长期预后有重要的临床意义。该文就循环肿瘤细胞在食管癌和胃癌中的表达及临床意义的研究进展进行综述。     

液体活检在淋巴瘤中的应用进展

正"液体活检"是通过血液样本检测肿瘤DNA的一种无创手段。肿瘤DNA在血液中以细胞形式即循环肿瘤细胞(circulating tumor cells,CTCs)或者游离形式即血清游离DNA (cell-free DNA,cfDNA)被检测到。cfDNA是细胞坏死或者凋亡之后进入血液的长度较短(200个碱基对)的双链DNA,肿瘤组织和非肿瘤组织都可以产生cfDNA,其中肿瘤组织来源的DNA即循环肿瘤DNA(circulating-tumor DNA,ctDNA)~([1-2])。随着测序技术的不断进展,尤其是二代测序技术的兴起,测序深     

循环肿瘤DNA在非小细胞肺癌中的研究进展

肺癌是全世界发病率及病死率最高的恶性肿瘤,其早期诊断和监测复发与转移对提高肺癌患者5年生存率尤为重要.循环肿瘤DNA (circulating tumor DNA,etDNA)是一种存在于人体体液中的细胞外游离状态的DNA.非小细胞肺癌(non-small cell lung cancer,NSCLC)患者血浆或血清ctDNA水平要显著高于健康志愿者,而且许多研究证实ctDNA水平有助于NSCLC的诊断、分期、预测疗效及判断预后.NSCLC患者ctDNA中也发现了许多基因的改变,如微卫星不稳定、杂合性丢失、DNA甲基化及基因突变.这些研究证明ctDNA可能有助于动态监测基因变化.本文就近年来ctDNA在NSCLC领域的研究进展进行综述.     

循环肿瘤细胞检测方式及临床应用

循环肿瘤细胞（CTC）指从实体肿瘤原发病灶或转移病灶脱落进入循环系统的肿瘤细胞亚群，其在肿瘤疾病进展、转移、复发中发挥着重要作用。CTC的有效检测及纯化对其临床应用、肿瘤疾病进展、转移及复发的机制研究尤为重要，并为肿瘤的个体化治疗提供可能。     

循环肿瘤细胞检测在胰腺癌早期诊断中的作用

胰腺癌是一种恶性程度很高的消化系肿瘤.因胰腺癌的早期临床症状不典型且具有隐蔽性,使胰腺癌的早期诊断十分困难,大部分群体一旦确诊即为晚期,难以治愈.因此胰腺癌的早期诊断成为国内外的研究热点.循环肿瘤细胞是存在于患者外周血中的肿瘤细胞,主要反映肿瘤的转移情况,但也有研究发现循环肿瘤细胞在原发癌诊断前可能已进入血液.如果早期在患者的外周血中检测到循环肿瘤细胞的存在,这将会增大肿瘤的早期诊断几率.本文主要介绍循环肿瘤细胞的检测方法及其在胰腺癌诊断中的作用.     

循环DNA与恶性肿瘤关系研究进展

健康人或一般疾病患的外周血中有很少量的游离DNA，而肿瘤病人外周血中的DNA明显增多。已经从肿瘤病人血浆提取的基因物质中发现肿瘤DNA特征性改变，如：DNA链稳定性降低、存在特殊癌基因、肿瘤抑制基因及微卫星改变。在白血病、结肠癌、胰腺癌病人血清中发现ras基因畸变，有时可早于临床诊断；在非何杰金氏淋巴瘤和急性B细胞白血病病人血浆中可发现免疫球蛋白重链DNA重排现象：头颈、肺和肾细胞癌血清／血浆中可见微小卫星不稳定状态。对大量不同肿瘤病人血清DNA的研究使开展肿瘤的无创性诊断、预后及疗效观察、随访成为可能。本就有关研究作一综述。     

ctDNA在B细胞淋巴瘤中的研究进展

摘要 循环肿瘤DNA（ctDNA）是肿瘤患者体液循环中一种广泛存在的游离DNA片段，相较于肿瘤实体病灶，ctDNA具有取材方便、安全无创、信息全面等优势。ctDNA检测可应用于B细胞淋巴瘤的治疗前、治疗中和治疗后等各个阶段，在肿瘤辅助诊断、预后分层、靶向治疗、疗效评估、微小残留病灶（MRD）监测及预测复发等方面具有重要指导意义。本文主要就ctDNA在B细胞淋巴瘤中的相关检测手段、应用进展和前景展望等作一概述。     

肿瘤坏死因子相关凋亡诱导配体联合柔红霉素诱导急性髓系白血病细胞凋亡的研究

目的探讨肿瘤坏死因子相关凋亡诱导配体(TRAIL)联合柔红霉素(DNR)诱导急性髓系白血病细胞凋亡的作用。方法分离21例急性髓系白血病患者的骨髓或外周血单个核细胞,每例分为4组进行观察：空白对照组、TRAIL组、DNR组、TRAIL DNR组,共同培养6、12、24小时。通过MTr比色法测定细胞杀伤率、DNA电泳及流式细胞仪检测细胞凋亡。结果TRAIL和柔红霉素可协同降低急性髓系自血病细胞活力,抑制细胞增殖,诱导细胞凋亡,其作用随培养时间延长及药物浓度增加而增强。结论TRAIL与柔红霉素具有协同作用,能高效杀灭肿瘤细胞。TRAIL是一种有望应用于临床的新型生物制剂。     

Prognostic and predictive blood biomarkers in gastric cancer and the potential application of circulating tumor cells

Gastric cancer(GC), with its high incidence and mortality rates, is a highly fatal cancer that is common in East Asia particularly in China. Its recurrence and metastasis are the main causes of its poor prognosis. Circulating tumor cells(CTCs) or other blood biomarkers that are released into the circulating blood stream by tumors are thought to play a crucial role in the recurrence and metastasis of gastric cancer. Therefore, the detection of CTCs and other blood biomarkers has an important clinical significance; in fact, they can help predict the prognosis, assess the staging, monitor the therapeutic effects and determine the drug susceptibility. Recent research has identified many blood biomarkers in GC, such as various serum proteins, autoantibodies against tumor associated antigens, and cell-free DNAs. The analysis of CTCs and circulating cell-free tumor DNA(ctDNA) in the peripheral blood of patients with gastric cancer is called as liquid biopsy. These blood biomarkers provide the disease status for individuals and have clinical meaning. In this review, we focus on the recent scientific advances regarding CTCs and other blood biomarkers, and discuss their origins and clinical meaning.     

Liquid biopsy in patients with pancreatic cancer: Circulating tumor cells and cell-free nucleic acids

Despite recent advances in surgical techniques and perioperative management, the prognosis of pancreatic cancer(PCa) remains extremely poor. To provide optimal treatment for each patient with Pca, superior biomarkers are urgently needed in all phases of management from early detection to staging, treatment monitoring, and prognosis. In the blood of patients with cancer, circulating tumor cells(CTCs) and cell-free nucleic acids(cf NAs), such as DNA, m RNA, and noncoding RNA have been recognized. In the recent years, their presence in the blood has encouraged researchers to investigate their potential use as novel blood biomarkers, and numerous studies have demonstrated their potential clinical utility as a biomarker for certain types of cancer. This concept, called "liquid biopsy" has been focused on as a less invasive, alternative approach to cancer tissue biopsy for obtaining genetic and epigenetic aberrations that contribute to oncogenesis and cancer progression. In this article, we review the available literature on CTCs and cfN As in patients with cancer, particularly focusing on PCa, and discuss future perspectives in this field.     

内镜超声引导下细针穿刺胰腺癌门静脉血测定循环肿瘤细胞的临床研究

目的评估用内镜超声引导下细针抽吸术(EUS-FNA)于胰腺癌门静脉采血检测循环肿瘤细胞(CTCs)的安全性及有效性。方法该研究为一项前瞻性单中心临床研究,纳入5例胰腺癌患者,行EUS-FNA门静脉采血。以外周血CTCs为对照,采用阴性免疫磁珠联合FISH法和叶酸受体阳性CTCs检测试剂盒检测门静脉血和外周血CTCs的细胞含量。结果5例患者EUS-FNA下门静脉采血均成功。1例出现血液凝集,未能进行CTCs检测。4例患者进行检测,3例门静脉血和外周血检测到CTCs。其中门静脉血CTCs细胞含量为(10.5±4.0)FU/3.7 mL,外周血CTCs含量为(11.4±4.2)FU/3.7 mL,两组比较差异无统计学意义(P>0.05)。术中术后无感染、腹腔出血和休克等并发症。结论内镜超声引导下胰腺癌门静脉血CTCs测定是一项安全可行的方法,可有助于胰腺癌早期转移的预估和治疗方案的选择。     

TRAIL-coated leukocytes that kill cancer cells in the circulation

Metastasis through the bloodstream contributes to poor prognosis in many types of cancer. Mounting evidence implicates selectin-based adhesive interactions between cancer cells and the blood vessel wall as facilitating this process, in a manner similar to leukocyte trafficking during inflammation. Here, we describe a unique approach to target and kill colon and prostate cancer cells in the blood that causes circulating leukocytes to present the cancer-specific TNF-related apoptosis inducing ligand (TRAIL) on their surface along with E-selectin adhesion receptor. This approach, demonstrated in vitro with human blood and also in mice, mimics the cytotoxic activity of natural killer cells and increases the surface area available for delivery of the receptor-mediated signal. The resulting “unnatural killer cells” hold promise as an effective means to neutralize circulating tumor cells that enter blood with the potential to form new metastases.Over 90% of cancer-related deaths are due to cancer metastasis, the spread of cancer cells from a primary tumor to anatomically distant organs (1). In many types of cancer, cancer cells from the primary tumor can intravasate into the peripheral circulation as circulating tumor cells (CTCs) (2, 3). These CTCs can then interact with the receptor-bearing endothelial cell wall under flow in other organs, in a manner similar to leukocyte extravasation during inflammation and lymphocyte homing to lymphatic tissues (4). Recent studies have shown that CTCs from many types of primary tumors express sialylated carbohydrate ligands similar to leukocytes, which mediate interactions with selectins on the endothelium (5, 6). Selectins possess rapid, force-dependent binding kinetics, which can trigger the rolling adhesion of CTCs along the blood vessel wall (7, 8). CTCs can subsequently transition from rolling to firm adhesion, allowing for transendothelial migration into tissues and eventual formation of micrometastases (9). Surgery and radiation have proven effective at treating primary tumors that do not invade the basement membrane; however, the difficulty of detecting distant micrometastases has made the majority of metastatic cancer treatments unsuccessful.The development of technologies to directly target CTCs in vivo holds promise in reducing both the metastatic load and the formation of new tumors. Although studies have reported that as many as 1 × 10⁶ cancer cells detach from the primary tumor (per gram) of patients per day (10, 11), CTCs are difficult to detect due to their sparse concentrations in the bloodstream, as low as 1–100 cells per mL (3, 12). Additionally, there are ∼1 × 10⁶ leukocytes or 1 × 10⁹ erythrocytes per single CTC in blood (13). Despite the difference in numbers, both leukocytes and CTCs share similar characteristics in terms of their migration within the bloodstream. Highly deformable erythrocytes experience a drift velocity away from the vessel wall and collect in the center region, displacing less deformable leukocytes and CTCs to the near-wall region in a mechanism termed margination (14). Such margination phenomena can effectively surround CTCs within the circulating leukocyte population, thus making leukocytes a potentially attractive carrier of treatments to CTCs by exploiting their numerous adhesion receptors.The utilization of leukocytes to treat CTCs directly within the bloodstream has not previously been explored. Here, we describe a therapeutic approach to target and kill circulating cancer cells in the bloodstream by functionalizing leukocytes with the apoptosis-inducing ligand TRAIL, and the adhesion receptor E-selectin directly within blood under shear flow. The functionalization of leukocytes under flow, effectively creating a form of “unnatural killer cells” within the bloodstream, is shown to be highly effective at treating circulating cancer cells in flowing human blood in vitro, and in the peripheral circulation of mice in vivo.     

Liquid biopsy of gastric cancer patients:Circulating tumor cells and cell-free nucleic acids

To improve the clinical outcomes of cancer patients,early detection and accurate monitoring of diseases are necessary.Numerous genetic and epigenetic alterations contribute to oncogenesis and cancer progression,and analyses of these changes have been increasingly utilized for diagnostic,prognostic and therapeutic purposes in malignant diseases including gastric cancer(GC).Surgical and/or biopsy specimens are generally used to understand the tumor-associated alterations;however,those approaches cannot always be performed because of their invasive characteristics and may fail to reflect current tumor dynamics and drug sensitivities,which may change during the therapeutic process.Therefore,the importance of developing a non-invasive biomarker with the ability to monitor real-time tumor dynamics should be emphasized.This concept,so called"liquid biopsy",would provide an ideal therapeutic strategy for an individual cancer patient and would facilitate the development of"tailor-made"cancer management programs.In the blood of cancer patients,the presence and potent utilities of circulating tumor cells(CTCs)and cell-free nucleic acids(cfNAs)such as DNA,mRNA and microRNA have been recognized,and their clinical relevance is attracting considerable attention.In this review,we discuss recent developments in this research field as well as the relevance and future perspectives of CTCs and cfNAs in cancer patients,especially focusing on GC.     

New blood markers detection technology: A leap in the diagnosis of gastric cancer

Gastric cancer(GC) is still one of the malignant tumors with high morbidity and mortality in the world, with a 5-year survival rate of less than 30%. GC is often either asymptomatic or causes only nonspecific symptoms in its early stages, whereas when the symptoms manifest, the cancer has usually reached an advanced stage, which is one of the main causes of its relatively poor prognosis. Hence, the main focus of GC research has been on discovering new tools and technology to predict, screen and diagnose g C at an early stage which would prompt early treatment. With the tremendous advances in the OMICS technology, serum proteomics has been in the limelight of cancer research over the last few decades and has steered the development of several methods helping to understand the mechanisms underlying gastric carcinogenesis, resulting in the identification of a large number of molecular targets such as circulating tumor cells(CTCs), cell free DNA(cf DNA) and cell tumor DNA(ct DNA) and their sub-molecular components such as mi RNA, that show great promise as GC biomarkers. In this review, we are underlying the recent breakthroughs about new blood markers technology for GC while scrutinizing the potential clinical use of CTCs, cf DNA, ct DNA and the role of the methylation of their submolecular components in the pathogenesis, diagnosis and management of GC.     

Liquid biopsy leads to a paradigm shift in the treatment of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) is one of the most cancers. Its 5-year survival rate is very low. The recent induction of neoadjuvant chemotherapy and improvements in chemotherapy for patients with pancreatic cancer have resulted in improved survival outcomes. However, the prognosis of pancreatic cancer is still poor. To dramatically improve the prognosis, we need to develop more tools for early diagnosis, treatment selection, disease monitoring, and response rate evaluation. Recently, liquid biopsy (circulating free DNA, circulating tumor DNA, circulating tumor cells, exosomes, and microRNAs) has caught the attention of many researchers as a new biomarker that is minimally invasive, confers low-risk, and displays an overall state of the tumor. Thus, liquid biopsy does not employ the traditional difficulties of obtaining tumor samples from patients with advanced PDAC to investigate their molecular biological status. In addition, it allows for long-term monitoring of the molecular profile of tumor progression. These could help in identifying tumor-specific alterations that use the target structure for tailor-made therapy. Through this review, we highlighted the latest discoveries and advances in liquid biopsy technology in pancreatic cancer research and showed how it can be applied in clinical practice.     

肺癌循环肿瘤细胞研究进展

肺癌是引起肿瘤相关死亡的首要原因.循环肿瘤细胞(CTCs)在肺癌的远处转移中起到关键作用.最近研究显示,CTCs水平可以预测肺癌患者的预后和治疗效果.CTCs检测作为一种“液体活检”具有更小的创伤性.CTCs可以及时反映患者的疾病状态,并为肺癌患者提供更好的个体化治疗策略.     

Circulating tumor cells in pancreatic cancer patients: Enrichment and cultivation

AIM:To investigate the feasibility of separation and cultivation of circulating tumor cells(CTCs)in pancreatic cancer(Pa C)using a filtration device.METHODS:In total,24 Pa C patients who were candidates for surgical treatment were enrolled into the study.Peripheral blood samples were collected before an indicated surgery.For each patient,approximately8 m L of venous blood was drawn from the antecubitalveins.A new size-based separation Meta Cell?technology was used for enrichment and cultivation of CTCs in vitro.(Separated CTCs were cultured on a membrane in FBS enriched RPMI media and observed by inverted microscope.The cultured cells were analyzed by means of histochemistry and immunohistochemistry using the specific antibodies to identify the cell origin.RESULTS:CTCs were detected in 16 patients(66.7%)of the 24 evaluable patients.The CTC positivity did not reflect the disease stage,tumor size,or lymph node involvement.The same percentage of CTC positivity was observed in the metastatic and non-metastatic patients(66.7%vs 66.7%).We report a successful isolation of CTCs in Pa C patients capturing proliferating cells.The cells were captured by a capillary action driven size-based filtration approach that enabled cells cultures from the viable CTCs to be unaffected by any antibodies or lysing solutions.The captured cancer cells displayed plasticity which enabled some cells to invade the separating membrane.Further,the cancer cells in the“bottom fraction”,may represent a more invasive CTC-fraction.The CTCs were cultured in vitro for further downstream applications.CONCLUSION:The presented size-based filtration method enables culture of CTCs in vitro for possible downstream applications.