第二军医大学  2014, Vol. 35 Issue (12): 1382-1386   PDF    
原发性肝癌患者外周血CD133CD105细胞水平及意义
徐永, 吴立胜, 方胜, 汪宏    
安徽医科大学第三附属医院微创外科, 合肥 230001
摘要目的 探讨原发性肝癌(HCC)患者外周血CD133+/CD105+细胞表达水平及其与临床预后的关系。方法 用流式细胞仪检测80例原发性肝癌患者和20例健康者CD45-/CD133+/CD105+细胞比例, 分析其与年龄、性别、临床分期、组织学分化程度、淋巴结转移及手术预后的关系, 采用Kaplan-Meier方法进行生存率分析,应用Cox比例风险模型进行多因素分析。结果 原发性肝癌患者外周血CD45-/CD133+/CD105+细胞水平较术后及健康对照组升高, 差异有统计学意义(P=0.003、P=0.000)。术后复发组术前外周血CD45-/CD133+/CD105+细胞水平高于术后未复发组,差异有统计学意义(P=0.015)。患者外周血CD45-/CD133+/CD105+细胞比例与临床分期、分化程度、有无淋巴结转移密切相关(均P<0.05),与年龄、性别无关。CD133与CD105的表达呈正相关(r=0.846, P<0.05)。患者外周血CD45-/CD133+/CD105+细胞比例> 0.5%者术后生存率较细胞比例≤0.5%者下降(P<0.05), CD45-CD133+细胞比例> 1.1%者术后生存率较细胞比例≤1.1%者降低(P<0.05), CD45-CD105+细胞比例> 36%者术后生存率较细胞比例≤36%者降低(P<0.05), 外周血CD45-/CD133+/CD105+细胞表达水平、分化程度、有无淋巴结转移是影响肝癌预后的独立因素。结论 肝癌患者外周血CD45-/CD133+/CD105+细胞表达水平明显升高并且与肝癌的恶性程度密切相关。外周血CD45-/CD133+/CD105+细胞表达水平降低是肝癌患者预后良好的独立因素, 是潜在的抗癌靶标。
关键词肝肿瘤     CD105     CD133     流式细胞术     预后    
Expression of CD133 and CD105 on cells in peripheral blood of patients with primary hepatocellular carcinoma
XU Yong, WU Li-sheng, FANG Sheng, WANG Hong    
Department of Minimally Invasive Surgery, The Third Affiliated Hospital of Anhui Medical University, Hefei 230001, Anhui, China
Abstract: Objective To investigate the relationship of CD133+ and CD105+ cells in the peripheral blood with the clinical prognosis of patients with primary hepatocellular carcinoma (HCC). Methods The proportions of CD45-CD133+CD105+ cells were determined in 80 primary HCC patients and 20 healthy subjects by flow cytometry, and the correlation of the proportion with age, gender, clinical stage, histological differentiation, lymph node metastasis, and surgical outcomes were analyzed. The survival rate was analyzed by Kaplan-Meier curves, and multivariate analysis was performed using Cox proportional hazards model. Results The proportion of CD45-CD133+CD105+ cells in the peripheral blood of primary HCC patients was significantly higher compared with those in the postoperative patients and healthy controls (P=0.003, P=0.000). The proportion of preoperative CD45-CD133+CD105+ cells in the postoperative recurrent group was significantly higher than those in the non-recurrent group (P=0.015). The proportion of CD45-CD133+CD105+ cells in the peripheral blood of primary HCC patients was significantly associated with the clinical stage, degrees of differentiation, and presence/absence of lymph node metastasis (P<0.05), and not associated with age or gender. CD133 expression was positively correlated with CD105 expression (r=0.846, P<0.05). Postoperative survival rate was significantly lower in patients with CD45-CD133+CD105+ proportion > 0.5% compared with ≤ 0.5% (P<0.05). The postoperative survival rate of patients with CD45-CD133+ cell proportion > 1.1% was significantly lower than that with CD45-CD133+ cell proportion ≤1.1% (P<0.05). The postoperative survival rate of patients with CD45-CD105+ proportion > 36% was significantly lower than those with CD45-CD105+ proportion ≤ 36% (P<0.05). Peripheral blood CD45-CD133+CD105+ cell proportion, degree of differentiation, and presence/absence of lymph node metastasis were the independent factors influencing HCC prognosis. Conclusion Proportion of CD45-CD133+CD105+ cells in the peripheral blood is greatly increased in HCC patients, which is closely associated with the degree of malignancy of HCC. Decreased CD45-CD133+CD105+ cell proportion in the peripheral blood is an independent favorable prognostic factor for HCC patients, and targeted lowering of CD45-CD133+CD105+ cell proportion in the peripheral blood of primary HCC patients may represent a new treatment.
Key words: primary hepatic carcinoma     CD105     CD133     flow cytometry     prognosis    

原发性肝癌(hepatocellular carcinoma,HCC)是消化系统最常见的恶性肿瘤之一,其发病率和死亡率均居高不下,目前手术是治疗HCC最有效的方法,但术后复发率较高[1,2]。研究[3,4]发现肝癌的高复发率和高死亡率与肿瘤干细胞关系密切,肝癌干细胞可能在肝癌早期已进入外周血液,并且在外周血中无限增殖,诱导正常肝细胞和肿瘤细胞的恶变,此外肝癌干细胞对化疗药物和放疗的治疗效应也产生对抗作用,为降低肝癌的死亡率和复发率,早期发现肝癌患者外周血中的肝癌干细胞已成为目前研究的热点。CD133是肿瘤干细胞的特征性标记物之一[5,6],CD105是肿瘤微血管标记物之一且与CD133关系密切,两者共同参与了肿瘤的发生和发展[7]。本研究拟通过检测HCC患者外周血CD133和CD105阳性细胞的水平,探讨二者在肝癌发生、发展及预后判断中的重要意义。 1 资料和方法 1.1 研究对象

2003年3月至2009年3月在安徽医科大学第三附属医院进行手术治疗的HCC患者216例,本研究回顾性分析了其中在知情同意下行肝门区域淋巴结清扫+肝脏切除术的肝癌患者80例。该80例患者术前常规检查AFP、右上腹CT增强扫描,其中25例行上腹部MRI,未发现有远处转移。术后病理诊断为肝细胞肝癌63例(伴肝硬化54例),胆管细胞癌11例(合并肝内胆管结石5例、伴肝硬化3例),混合型肝癌6例均伴有肝硬化。80例HCC患者中术前21例发生淋巴结转移,病理组织示肝细胞癌13例、胆管细胞癌5例、混合性肝癌3例。术中无死亡。80例患者中男41例、女39例,平均年龄(58.22±7.00)岁,分别于术前5~7 d收集患者外周血进行CD133、CD105检测。选取正常健康体检者20例作为对照,其中男 13例、女7例,平均年龄(57.74±8.28) 岁。所有HCC患者均经病理学证实,术前未经过放化疗和免疫治疗,术后都经正规的放化疗,所有患者均无其他系统恶性肿瘤病史。 1.2 主要试剂与仪器

抗人CD105-FITC抗体、抗人CD133-PE抗体、抗人CD45-PCy5抗体、FITC、PE和PCy5标记的小鼠IgG1同型对照、FC-500流式细胞仪、溶血素、离心机均购自美国Beckman Coulter 公司。磷酸盐缓冲液(PBS)购自大冢(中国)投资有限公司。 1.3 实验方法

所有观察对象于清晨空腹抽取外周静脉血2 mL。EDTA抗凝,2 h内送至流式细胞仪室,取流式细胞仪专用试管2支,A管中加CD105-FITC抗体、抗人CD133-PE抗体、抗人CD45-PCy5抗体各10 μL,B管中加相应同型对照液各10 μL,A、B管分别加入100 μL全血,混匀后避光反应约15 min,各加溶血素1 mL,再避光放置10 min,以1 500 r/min的速度离心5 min,弃上清液,各加缓冲液2 mL,同一速度离心5 min,弃上清液,加400 μL缓冲液后上机,用流式细胞仪检测,以Cell Quest软件获取分析数据,定量分析每管样品中30 000个细胞,以CD45-/CD133+/CD105+细胞为阳性细胞,记录阳性细胞百分率,减去非特异性对照值。 1.4 统计学处理

采用SPSS16.0软件进行统计学分析,计量资料以x±s表示,组间比较采用t检验,相关性分析采用Pearson列联系数r计算,采用Kaplan-Meier方法进行生存率分析,应用Cox比例风险模型进行多因素分析。检验水准(α)为0.05。 2 结 果 2.1 术前、术后外周血CD45-/CD133+/CD105+细胞水平变化

80例HCC患者术前外周血CD45-/CD133+/CD105+细胞水平为(0.632±0.562)%,术后为(0.437±0.379)%,术前外周血中CD45-/CD133+/CD105+细胞水平高于术后(t=3.252,P=0.003);且较健康对照组[(0.025±0.071)%]升高,差异有统计学意义(t=4.801,P=0.000)。此外,HCC患者术后复发组术前外周血CD45-/CD133+/CD105+细胞水平[(0.770±0.608)%]高于术后未复发组[(0.465±0.389)%],差异有统计学意义(t=2.489,P=0.015)。 2.2 CD45-/CD133+/CD105+细胞表达与临床病理学特征的关系

患者外周血CD45-/CD133+/CD105+细胞比例与性别、年龄无关。临床分期Ⅱ~Ⅲ期肝癌患者外周血CD45-/CD133+/CD105+细胞比例高于Ⅰ~Ⅱ期肝癌患者,差异有统计学意义(t=2.734,P=0.008)。高、中、低分化癌患者外周血CD45-/CD133+/CD105+细胞比例,两两比较差异均有统计学意义(均P<0.05)。有淋巴结转移肝癌患者外周血CD45-/CD133+/CD105+细胞比例高于无淋巴结转移者,差异有统计学意义(t=3.110,P=0.003)。具体数据见表 1

表 1 80例HCC患者CD45-/CD133+/CD105+细胞水平与临床特征的关系
2.3 HCC患者外周血中CD133和CD105蛋白表达之间的关系

80例HCC患者外周血中CD133随CD105阳性表达改变而改变者62例,二者呈正相关(r=0.846,P<0.05)。 2.4 CD45-CD133+、CD45-CD105+细胞表达水平与肝癌患者术后生存率的关系

对80例HCC患者电话或信件随访并进行Kaplan-Meier分析,比较其外周血中CD45-/CD133+/CD105+细胞的不同表达水平与生存率的关系,总生存期定义为自手术之日起至随访截止或死亡。外周血CD45-/CD133+/CD105+细胞比例>0.5%者术后生存率较细胞比例≤0.5%者降低(P<0.05,图 1A),CD45-/CD133+细胞比例>1.1%者术后生存率较细胞比例≤1.1%者降低(P<0.05,图 1B),CD45-/CD105+细胞比例>36%者术后生存率较细胞比例≤36%者降低(P<0.05,图 1C)。

图 1 CD45-/CD133+/CD105+、CD45-/CD133+和CD45-/CD105+的细胞表达水平与肝癌患者术后生存率的关系
2.5 影响预后的Cox模型多因素分析

外周血中CD45-/CD133+/CD105+细胞表达水平、分化程度、有无淋巴结转移是影响本组肝癌患者预后的独立因素(表 2)。

表 2 影响原发性肝癌术后预后的Cox模型多因素分析
3 讨 论

肝癌干细胞的研究尚处于初级阶段,研究发现在结肠癌、前列腺癌、脑胶质瘤中均存在CD133阳性细胞,并且与肿瘤的恶性程度密切相关[8,9,10]。CD105参与血管新生过程,从而促进肿瘤的生长、浸润和转移[11,12,13]。本课题组前期探讨了CD133和CD105阳性细胞在HCC患者中的增殖及侵袭作用,联合检测CD133和CD105双阳性细胞可以更加精确地筛选出肝癌干细胞,其部分实验结果已发表[14],此外,国外文献也已有相关实验[15,16]

由于CD133+和CD105+的细胞在外周血中非常少,因此,需要利用CD45进行富集以提高检测灵敏度。抗人CD45抗体又称抗人白细胞共同抗原抗体,它可以结合血源性白细胞,而不结合非血源性的肿瘤细胞。在使用流式细胞仪对单个核细胞检测时,考虑到CD45阴性的单核细胞可以从分离液和血浆之间分离[17,18],我们首先加CD45 Per CP以进行CD45/SSC双参数散电图设门,选中CD45-区域再进行下一步分析,从而将外周血单个核细胞中血源性白细胞去除,使该CD45-区域细胞全为肿瘤细胞,在此基础上进一步检测CD133、CD105阳性表达,可使CD133+CD105+肝癌干细胞的检测敏感性大幅提高。

本研究结果显示,术后肝癌患者外周血CD45-/CD133+/CD105+细胞水平低于术前(P<0.05),而健康正常人外周血几乎未见CD45-/CD133+/CD105+细胞[19]。这表明手术切除肿瘤后,外周血CD45-/CD133+/CD105+细胞比例下降,这有助于延缓肿瘤的进一步发展。本研究还发现CD45-/CD133+/CD105+细胞的表达与临床分期、分化程度以及淋巴结转移相关,有文献报道术中切除局部淋巴结可能提高患者预后[1, 20]。因此推测肝癌患者外周血CD45-/CD133+/CD105+细胞水平越高,患者的病情越严重,预后越差,原因可能与含有的肿瘤干细胞越多,新生血管增生越活跃,转移几率进一步增加有关[21]

本研究还发现,肝癌患者外周血中CD133与CD105的表达呈正相关,即肝癌外周血中CD133表达越高,CD105表达也越高。这可能是因为CD133作为一种肝癌干细胞,其可以促进或分化成血管内皮细胞,从而导致CD105的表达升高,促进肿瘤的生长、浸润和转移。

综上所述,肝癌患者外周血CD45-/CD133+/CD105+细胞表达水平明显升高,且与肝癌的恶性程度密切相关,另外其还极大地影响着患者预后,对CD45-/CD133+/CD105+细胞表达的进一步研究,可能会为预测肝癌复发及判断肝癌预后提供新的依据,靶向降低肝癌患者外周血CD45-/CD133+/CD105+细胞的数量将为肝癌的临床治疗提供一个应用前景。

4 利益冲突

所有作者声明本文不涉及任何利益冲突。

参考文献
[1] Kim K H,Lee S G,Park E H,Hwang S,Ahn C S,Moon D B,et al.Surgical treatments and prognoses of patients with combined hepatocellular carcinoma and cholangiocarcinoma[J].Ann Surg Oncol,2009,16:623-629.
[2] 徐本玲, 袁 龙, 高全立, 范瑞华, 张成娟, 宋永平.重组纤维连接蛋白诱导自体CIK联合IFN-α治疗晚期肝癌疗效[J].郑州大学学报(医学版), 2011,46:694-696.
[3] Kohga K,Tatsumi T,Takehara T,Tsunematsu H, Shimizu S,Yamamoto M,et al.Expression of CD133 confers malignant potential by regulating metalloproteinases in human hepatocellular carcinoma[J].J Hepatol,2010,52:872-879.
[4] Piao L S,Hur W,Kim T K,Hong S W,Kim S W,Choi J E,et al.CD133+ liver cancer stem cells modulate radioresistance in human hepatocellular carcinoma[J].Cancer Lett,2012,315:129-137.
[5] Pallini R,Ricci-Vitiani L,Montano N,Mollinari C,Biffoni M,Cenci T,et al.Expression of the stem cell marker CD133 in recurrent glioblastoma and its value for prognosis[J].Cancer,2011,117:162-174.
[6] Song W,Li H,Tao K,Li R,Song Z,Zhao Q,et al.Expression and clinical significance of the stem cell marker CD133 in hepatocellular carcinoma[J].Int J Clin Pract,2008,62:1212-1218.
[7] 程继荣,王淑琴,祖木热提, 邹 静.肺癌组织中CD133和CD105的表达及其临床意义[J].肿瘤, 2010,30:334-337.
[8] Park B S,Jung S Y,Kwon S M,Bae J H,Lee S M,Shin D H,et al.Comparison of putative circulating cancer stem cell detection between the hepatic portal system and peripheral blood in colorectal cancer patients[J].Ann Surg Treat Res,2014,87:232-238.
[9] Miki J,Furusato B,Li H,Gu Y,Takahashi H,Egawa S,et al.Identification of putative stem cell markers,CD133 and CXCR4,in hTERT-immortalized primary nonmalignant and malignant tumor-derived human prostate epithelial cell lines and in prostate cancer specimens[J].Cancer Res,2007,67:3153-3161.
[10] Singh S K,Hawkins C,Clarke I D,Squire J A,Bayani J,Hide T,et al.Identification of human brain tumour initiating cells[J].Nature,2004,432:396-401.
[11] Li Y,Zhai Z,Liu D,Zhong X,Meng X,Yang Q,et al.CD105 promotes hepatocarcinoma cell invasion and metastasis through VEGF[J].Tumour Biol,2014 Oct 7.[Epub ahead of print]
[12] Miyata Y,Mitsunari K,Asai A,Takehara K,Mochizuki Y,Sakai H.Pathological significance and prognostic role of microvessel density,evaluated using CD31,CD34,and CD105 in prostate cancer patients after radical prostatectomy with neoadjuvant therapy[J].Prostate,2014 Oct 13.[Epub ahead of print]
[13] Yoshitomi H,Kobayashi S,Ohtsuka M,Kimura F, Shimizu H,Yoshidome H,et al.Specific expression of endoglin (CD105) in endothelial cells of intratumoral blood and lymphatic vessels in pancreatic cancer[J].Pancreas,2008,37:275-281.
[14] 张俊松, 汪 宏, 吴立胜.CD105、CD133在人肝癌细胞株HepG-2的表达情况及生物学性状的体外研究[J].肝胆外科杂志, 2013, 21:133-136.
[15] Lee J S,Heo J,Libbrecht L,Chu I S,Kaposi-Novak P,Calvisi D F,et al.A novel prognostic subtype of human hepatocellular carcinoma derived from hepatic progenitor cells[J].Nat Med,2006,12:410-416.
[16] Tang Y,Kitisin K,Jogunoori W,Li C,Deng C X,Mueller S C,et al.Progenitor/stem cells give rise to liver cancer due to aberrant TGF-beta and IL-6 signaling[J].Proc Natl Acad Sci USA,2008,105:2445-2450.
[17] Jacob K,Sollier C,Jabado N.Circulating tumor cells: detection,molecular profiling and future prospects[J].Expert Rev Proteomics,2007,4:741-756.
[18] Naume B,Borgen E,Tssvik S,Pavlak N,Oates D,Nesland J M.Detection of isolated tumor cells in peripheral blood and in BM: evaluation of a new enrichment method[J].Cytotherapy,2004,6:244-252.
[19] Ma S.Biology and clinical implications of CD133(+) liver cancer stem cells[J].Exp Cell Res,2013,319:126-132.
[20] Agrawal S,Belghiti J.Oncologic resection for malignant tumors of the liver[J].Ann Surg,2011,253:656-665.
[21] Hou Y,Zou Q,Ge R,Shen F,Wang Y.The critical role of CD133(+)CD44(+/high) tumor cells in hematogenous metastasis of liver cancers[J].Cell Res,2012,22:259-272.