K562多药耐药细胞系中肿瘤干细胞样细胞对伊马替尼耐药机制的初步研究

Objective： To characterize a novel chronic myeloid leukemia （CML） cell line and to further elucidate the mechanisms of resistance to STI571. Methods： A novel K562 cell line （K562NP16） was achieved after exposure of the K562 cells to VP16. A small subpopulation （K562NP16 SP） that was capable of excluding Hoechst 33342 in the K562NP16 cell line was isolated by fiow cytometry sorting. The rest of the K562NP16 cells were classified as non-SP K562NP16. The mechanisms involved in K562NP16 SP cells which became resistant to STI571 were studied. Results： The levels of Bcr-Abl and Abl proteins were similar in the K562 cell line and in non-SP K562NP16 and K562NP16 SP cells. The multidrug-resistant gene 1 （MDR1） expression of the 170 kDa P-glycoprotein （P-gp） was detected in K562NP16 non-SP and K562NP16 SP cells but not in K562 cells. The expression levels of P-gp in the two K562NP16 cell lines were similar. Compared with non-SP K562/ VP16, the K562NP16 SP cells were more resistant to STI571. This resistance could hardly be reversed by many multidrug resistance inhibitors. In addition, in vivo study showed that the K562NP16 SP cells induced tumorigenesis in mice, while the K562NP16 non-SP cells failed to do so. Conclusion： A novel K562 cell line, K562NP16, was generated. A small side population K562NP16 SP cells, had high resistance to STI571 treatment and more tumorigenic than the K562 cells. It may represent the cancer stem cells of the K562NP16 cell line.     

Isolation of Side Population Cells and Detection of ABCG2 from SW480

Objective:Side population cells(SP cells)are a new type of stem cells.They mainly express ABCG2/BCRP1 and have the ability to eliminate DNA dye Hoechst33342.Many studies showed that side population cells were able of self-renewal,differentiation and carcinogenesis in cancers.Our investigation aimed at isolation of side population cells and ABCG2 positive subpopulation from colon cancer cell line SW480 and identification of their characteristics of cancer stem cells.Methods:side population cells and non-side population cells of colon cancer cell line SW480 were isolated with DNA dye Hoechst33342 and their cell cycles were measured by flow cytometry.Expression of ABCG2 of SW480 was measured by immunohistochemistry and immunofluorescence,and its proportion was measured by flow cytometry.Results:SW480 contained 2.29% side population cells.The fraction of side population cells decreased greatly to 0.40% by treatment with verapamil.The fraction of side population cells in S-G2M cell cycle was 16.14%,which was much lower than the fraction(34.05%)of non-side population cells in S-G2M.In SW480,ABCG2 positive cells,which proportion was 9.66%,were small,circular or oval,lack of psuedopods,similar to poor differentiation.On the contrary,the ABCG2 negative cells were large,polygonal,with many psuedopods,similar to high differentiation.Conclusion:our assay identified that side population cells did exist in SW480 and had a quiescence characteristic of stem cells.ABCG2 positive subpopulation occupied about 9.66% of SW480 and may have the ability to promote cell self-renewal and inhibit cell differentiation.Therefore,to isolate ABCG2 positive subpopulation from side population cells may be an alternative to study colorectal cancer stem cells.     

人肺腺癌A549细胞系干细胞相关亚群的分离与鉴定

目的 分离人肺腺癌A549细胞系中的侧群(SP)细胞亚群并探讨其细胞特性.方法 采用免疫组化法检测人肺腺癌A549细胞系中ABCG2蛋白的表达.采用流式细胞术分选A549细胞系中的SP和非SP细胞亚群,并检测两亚群细胞的分化功能.采用逆转录聚合酶链反应(RT-PCR)方法检测两亚群细胞的ABCG2蛋白表达,通过两亚群细胞的生长曲线、细胞分裂指数、细胞周期各时相分布、平板克隆形成实验、体外侵袭和迁移实验、化疗药敏试验、细胞内药物浓度测定以及裸鼠移植瘤实验,比较两亚群细胞的生物学行为,并用RT-PCR和免疫组化方法检测移植瘤组织中ABCG2的表达.结果 A549细胞系中ABCG2蛋白的阳性表达率为2.13%.通过流式细胞术能成功分选得到SP细胞和非SP细胞,SP细胞亚群可产生SP及非SP两种细胞,而非SP细胞只能产生非SP细胞.SP细胞表达ABCG2,非SP细胞则不表达.两细胞亚群的增殖、迁移能力相似,吸光度、分裂指数、细胞周期时相分布和细胞体外迁移实验穿过滤膜的细胞数差异均无统计学意义(均P＞0.05),但SP细胞的侵袭能力和成瘤能力强于非SP细胞,细胞体外侵袭实验穿过滤膜的细胞数、体外细胞克隆形成数和移植瘤成瘤率均高于非SP细胞(P＜0.01,P＜0.01,P＜0.05).SP细胞和非SP细胞对顺铂(DDP)的敏感性和细胞内药物浓度相似,非SP细胞对5-氟尿嘧啶(5-Fu)、依托泊苷(VP-16)、长春瑞滨(NVB)和吉西他滨(GEM)的敏感性及细胞内药物浓度则高于SP细胞(均P＜0.01).结论 人肺腺癌A549细胞系SP细胞亚群富集了肺癌干细胞,通过流式细胞仪分选肺腺癌SP细胞亚群是分离肺腺癌干细胞的有效方法.

Abstract：

Objective To isolate and characterize the side population cells(SP cells) in the lung adenocarcinomas cell line A549. Methods The protein expression of ABCG2 in human lung adenocarcinoma cell line A549 was detected by immunohistochemistry.SP and NSP cells in the cell line A549 were isolated by FACS,and their differentiation was analysed.ABCG2 expression in the two cell subsets was detected by RT-PCR.The cell growth curves,cell division indexes,cell cycles,plate clone formation tests,migration and invasion assays,chemotherapeutic susceptibility tests,tests of the intracellular drug levels,and the tumor cell implantation experiments on nude mice were applied to study the biological properties of the two cell subsets.The expression of ABCG2 in the transplanted tumor in nude mice was detected by immunohistochemistry and RT-PCR. Results The positive rate of ABCG2 expression in the A549 cells by immunohistochemistry was 2.13%.SP and NSP cells were isolated by FACS.The SP cells could produce both SP and NSP cells,while NSP cells only produced NSP cells.SP cells expressed ABCG2,but NSP cells did not.The proliferation and migration abilities of the two cell subsets were similar,but the invasion and tumorigenic ability of SP cells was significantly higher than that of NSP cells.The susceptibilities to DDP and its intracellular levels of the two cell subsets were similar,but the susceptibilities to 5-FU,VP16,NVB and GEM and their intracellular levels of NSP cells were significantly higher than those of the SP cells. Conclusions SP cells in the human lung adenocarcinomas cell line A549 is enriched with tumor stem cells.An effective way to get lung adenocarcinomas stem cells is to isolate SP cells by FACS.     

ABCG2-overexpressing S1-M1-80 cell xenografts in nude mice keep original biochemistry and cell biological properties

S1-M1-80 cells,derived from human colon carcinoma S1 cells,are mitoxantrone-selected ABCG2-overexpressing cells and are widely used in in vitro studies of multidrug resistance(MDR).In this study,S1-M1-80 cell xenografts were established to investigate whether the MDR phenotype and cell biological properties were maintained in vivo.Our results showed that the proliferation,cell cycle,and ABCG2 expression level in S1-M1-80 cells were similar to those in cells isolated from S1-M1-80 cell xenografts(named xS1-M1-80 cells).Consistently,xS1-M1-80 cells exhibited high levels of resistance to ABCG2 substrates such as mitoxantrone and topotecan,but remained sensitive to the non-ABCG2 substrate cisplatin.Furthermore,the specific ABCG2 inhibitor Ko143 potently sensitized xS1-M1-80 cells to mitoxantrone and topotecan.These results suggest that S1-M1-80 cell xenografts in nude mice retain their original cytological characteristics at 9 weeks.Thus,this model could serve as a good system for further investigation of ABCG2-mediated MDR.     

MTA1基因表达与人骨肉瘤细胞浸润和转移的关系

Objective： To compare the expression level of metastasis associated-1 （MTA1） in the higher and lower metastasis sublines of human osteosarcoma cells （MG63）, and to investigate the relationship between the expression level of MTA1-EGFP and in vitro invasion and metastasis of human osteosarcoma cells. Methods： The expression level of MTA1 in two sublines of MG63 cells was detected by semi-quantitative RT-PCR, and cell invasion assay and cell proliferation assay were used to evaluate the invasive capacity in vitro in two sublines. The lower metastasis line of MG-63 cells were transfected with MTA1-EGFP full-length cDNA expression plasmid by lipofectamine. The changes of the MTA1-EGFP expression and in vitro invasion potential were measured after transfection. Results： M8 subline expressed significantly higher level of MTA1 than that of M6 subline by RT-PCR. The invasive potentials of low metastasis MG63 cell line were increased after MTA1 gene transfection. Conclusion： There may be a relationship between MTA1 and invasive potentials of human osteosarcoma cells, and MTA1 may play a role in the molecular mechanism of tumor metastases and be a potential target for gene therapy of osteosarcoma. Further studies of MTA1 in human ostersarcoma cell metastasis are needed.     

Expression of a mutant hTERT in human bladder carcinoma cell line T24 and its clinical significance

Objective: To construct a mutant pEGFP- hTERT expression vector, to observe its steady expression in transfected human bladder carcinoma cell line T24 and its role in molecular regulatory mechanisms of telomerase, and to provide a new target gene for bladder cancer. Methods:PCR amplification was performed by using primers based on the known gene sequence of hTERT. PCR production was cloned into plasmid pGEMT-T easy and the sequence of mutant hTERT gene was analyzed. A recombinant mutant hTERT vector (pEGFP-hTERT) was constructed at the EcoR I and Sa/I sites of the pEGFP-C1 vector. After transfecting the fusion gene into bladder carcinoma cell line T24 by calcium phosphate-DNA coprecipitation, the steady expression of GFP-hTERT fusion protein was tested by fluorescent light microscopy. The proliferation changes of bladder carcinoma cell line T24 were detected by light microscopy and senescence correlated [3-galactosidase staining. Results: Identification of pEGFP-hTERT by enzyme digestion showed that mutant hTERT fragment had been cloned into EcoR I and Sal I sites of the pEGFP-C1 vector. The steady expression of GFP-hTERT fusion protein was localized in the nucleus of transfected cells. Expression of senescence-associated ~-galactosidase in transfected cells gradually increased with extended cultured time and cell growth was suppressed. Conclusion: The mutant-type hTERT gene suppresses the proliferation of bladder carcinoma cell line T24 by competitive effect on telomerase activity. This suggests that hTERT gene might be a suitable gene target for bladder cancer therapy.     

High Expression of the RECK Gene in Breast Cancer Cells is Related to Low Invasive Capacity

OBJECTIVE To investigate the expression of the RECK gene in human breast (cancer) cell lines, and to determine the relationship between RECK gene expression and the invasive capacity of the breast cancer cell lines. METHODS The invasive capacity of breast (cancer) cell lines including HBL-100, MCF-7 and MDA-MB-435S were determined by the Tran-swell method. The protein expression levels of RECK, MMP-2 and MMP-9 genes in these three cell lines were measured by immunocytochemical methods. The expressions of the RECK gene and protein level were measured by RT-PCR and Western blots in the cell lines respectively. RESULTS The order of the invasive capacity of the breast (cancer) cell lines was MDA-MB-435S, being the highest, and HBL-100, being the lowest. The invasive capacity difference between any two groups among the three groups was significant (P<0.01). The protein expression level of the RECK gene in the HBL-100 cell line was highest, and no expression was detected in MDA-MB-435S cells. Moreover, the expression of the RECK gene was negatively correlated with the expression of the MMP-2 and MMP-9 genes. The mRNA level of the RECK gene in HBL-100 cells was the highest, but no expression was found in the MDA-MB-435S cells (P<0.001). CONCLUSION There was a significant negative correlation between the expression level of the RECK gene and invasive capacity in vitro, and the RECK gene expression showed an inverse proportion to that of the MMP-2, MMP-9 genes.     

人胆囊癌SP细胞的分离及其干细胞标记物的表达*

目的:探索在人胆囊癌GBC-SD 细胞系中是否存在具有干细胞特性的SP细胞（side population cells）,以及SP细胞、非SP细胞和GBC-SD 细胞系表达常见干细胞标记物ABCG2、Oct- 4、CD34的情况。方法:采用荧光激活细胞分选技术（FACS）分选出人胆囊癌SP细胞和非SP细胞,通过RT-PCR、Western blot、流式细胞术以及免疫荧光化学技术检测SP细胞、非SP细胞以及GBC-SD 细胞系表达ABCG2、Oct- 4 和CD34的情况。结果:人胆囊癌GBC-SD 细胞系中存在着少量的具有干细胞潜能的SP细胞,其所占的比例为（0.64± 0.08）% ,SP细胞相对于非SP细胞和GBC-SD 细胞,具有更强的体外侵袭力（P<0.05）;并且ABCG2 在胆囊癌SP细胞中呈现出高表达的状态（89.56±3.86）% ,在非SP细胞中几乎不表达（1.32± 0.49）% ,在未分选胆囊癌细胞系中ABCG2 呈弱表达（12.37± 1.61）% ,P=0.001;Oct- 4 在三种细胞中的表达分别为:（94.87± 1.40）% 、（88.16± 2.34）% 、（90.17± 1.61）% ,P>0.05;CD34在mRNA水平高表达于非SP细胞和GBC-SD 细胞,不表达于SP细胞;在蛋白水平几乎均不表达于这三种细胞,其含量依次为:（1.78± 0.51）% 、（0.63± 0.21）% 、（0.96± 0.38）% ,P>0.05。结论:人胆囊癌GBC-SD 细胞系中存在具有干细胞特性的SP细胞,并且具有ABCG2+Oct- 4+CD34-的表型特征。      

肾癌细胞株786-0侧群细胞生物学特性与XIAP mRNA表达的研究

目的 肿瘤干细胞在肿瘤复发和耐药中起着关键作用,侧群(side population,SP)细胞中富含肿瘤干细胞.本研究探讨肾癌786-0细胞株中SP细胞的生物学特性及凋亡抑制蛋白XIAP在SP中的表达.方法 制备肾癌786-0细胞株单细胞悬液,Hoechst33342染色,流式细胞荧光激活技术分选出肾癌786-0细胞系中的SP细胞和非侧群(non-SP,NSP)细胞2个亚群,MTT法绘制细胞生长曲线,比较SP细胞和NSP细胞的增殖能力;无血清悬浮培养观察两组亚群细胞肿瘤球形成能力,流式细胞仪检测两组亚群细胞体外分化能力;实时荧光定量PCR法检测SP细胞、NSP细胞及未经分选的肾癌786-0细胞XIAP mRNA的表达情况.结果 流式细胞分选结果显示,肾癌786-0细胞株中SP细胞所占比例为(2.9±0.1)％.细胞生长曲线结果显示,SP细胞增殖速度快,与NSP细胞增殖能力比较,差异有统计学意义,t=4.32,P=0.033.SP细胞在无血清培养基中的肿瘤球形成能力强于NSP细胞;无血清培养2周后SP细胞亚组SP细胞所占比例下降为(18.1±0.3)％,提示SP细胞可以分化为NSP细胞.XIAP mRNA在SP细胞中的表达量为10.74±0.25,与NSP细胞亚组及未经分选的786-0细胞比较差异有统计学意义,F=61.02,P=0.012.结论 肾癌786-0细胞株中存在具有干细胞特性的SP细胞,高表达凋亡抑制蛋白XIAP,SP细胞可作为肾癌分子靶向治疗研究的切入点.     

Isolation and characterization of cancer stem-like side population cells in human oral cancer cells

Recent studies suggest that cancer stem cells may be responsible for tumorigenesis and contribute to some individuals’ resistance to cancer therapy. Some studies demonstrate that side population (SP) cells isolated from diverse cancer cell lines harbor stem cell-like properties; however, there are few reports examining the role of SP cells in human oral cancer. To determine whether human oral cancer cell lines contain a SP cell fraction, we first isolated SP cells by fluorescence activated cell sorting, followed by culturing in serum-free medium (SFM) using the SCC25 tongue cancer cell line, so that SP cells were able to be propagated to maintain the CSC property. Differential expression profile of stem cell markers (ABCG2, Oct-4 and EpCAM) was examined by RT-PCR in either SP cells or non-SP cells. Growth inhibition by 5-FU was determined by the MTT assay. Clonogenic ability was evaluated by colony formation assay. SCC25 cells contained 0.23% SP cells. The fraction of SP cells was available to grow in SFM cultures. SP cells showed higher mRNA expression of stem cell markers (ABCG2, Oct-4 and EpCAM) as compared with non-SP cells. Moreover, SP cells demonstrated more drug resistance to 5-FU, as compared with non-SP cells. The clone formation efficiency of SP cells was significantly higher than non-SP cells at an equal cell number (P < 0.01). We isolated cancer stem-like SP cells from an oral cancer cell line. SP cells possessed the characteristics of cancer stem cells, chemoresistance, and high proliferation ability. Further characterization of cancer stem-like SP cells may provide new insights for novel therapeutic targets.     

The multidrug resistance transporter ABCG2 (breast cancer resistance protein 1) effluxes Hoechst 33342 and is overexpressed in hematopoietic stem cells.

The human ATP-binding cassette superfamily G (White) member 2 (ABCG2) gene and its murine homologue breast cancer resistance protein 1 (Bcrp1) are recently described ATP-binding cassette transporters associated with drug resistance in tumor cell lines, including the MCF-7 cell line, selected for its resistance to mitoxantrone (MCF-7/MitoR). Infection of MCF-7 cells with the retroviral vector containing ABCG2 cDNA (G1-ABCG2) resulted in cells (MCF-7/ABCG2) that were resistant to mitoxantrone at levels similar to those observed in MCF-7/MitoR cells. Previous studies have shown that pluripotent hematopoietic stem cells overexpress the multidrug-resistant transport (MDR1) gene and efflux rhodamine, a substrate for the MDR1 transporter. Other studies have identified a primitive hematopoietic stem cell population, or side population (SP) cells, which are identified by their efflux of the fluorescent dye, Hoechst 33342. In an attempt to identify the transport genes responsible for this phenotype, we examined the uptake of Hoechst 33342 into MCF-7, MCF-7/MitoR, and MCF-7 cells infected with a retroviral vector expressing the ABCG2 gene (MCF-7/ABCG2). MCF-7/MitoR cells as well as MCF-7/ABCG2 cells demonstrated lower levels of Hoechst 33342 uptake compared with the parental MCF-7 cells. We also examined the level of the mouse Bcrp1 RNA in SP cells and non-SP cells isolated from mouse hematopoietic cells. Mouse SP cells expressed relatively high levels of Bcrp1 mRNA relative to non-SP cells. These results suggest that Hoechst 33342 is a substrate for the ABCG2 transporter and that ABCG2/Bcrp1 expression may serve as a marker for hematopoietic stem cells in hematopoietic cells.     

干细胞标志物在卵巢癌SKOV3细胞侧群细胞中的表达

目的：检测干细胞相关标志物在卵巢癌SKOV3细胞系侧群（side population,SP）细胞和非侧群（Non-SP）细胞中的表达差异,确定卵巢癌干细胞特异性标志物。 方法： Hoechst 33342染色检测SKOV3细胞中SP细胞的比例,流式细胞术检测SKOV3细胞的SP和Non-SP细胞中干细胞标志物CD133、CD117、CD44、ABCG2、ALDH1 的表达情况,荧光定量PCR检测SP和Non-SP细胞中 ABCG2、ALDH2、NANOG、OCT4、SOX2、CD133、CD117 mRNA的表达水平。 结果： SKOV3细胞中SP细胞比例为(1.56±0.35)%。 ALDH1、ABCG2在SP细胞中表达率分别为（87.3±5.76）%、（29.48±4.43）%,在Non-SP的表达率分别为（5.32±0.47）%、（3.01±1.69）%,差异有统计学意义（ P <0.01）;CD44在这两种细胞亚群中的表达率均高于99%（ P >005）;CD133、CD117在这两种细胞亚群中均不表达。 ALDH1、ABCG2、 NANOG、OCT4和SOX2 mRNA在SP细胞中的表达分别是Non-SP细胞的21.03倍（ P =0.001）、3.14倍（ P =0.001）、23.94倍（ P =0.001）、10.73倍（ P =0.009）和21.46倍( P =0001), CD133、CD117 mRNA在两种细胞亚群中均不表达。 结论： 人卵巢癌细胞株SKOV3中存在SP细胞亚群, ALDH1、ABCG2和NANOG、OCT4、SOX2 mRNA可能是卵巢癌干细胞标志物,为诊断及治疗卵巢癌提供了潜在的靶点。     

人骨肉瘤细胞MG-63侧群细胞的分离及耐药性研究

 目的 分选人骨肉瘤细胞MG-63中的侧群（side population,SP）细胞,并探讨SP细胞对化疗药物耐药的机制。方法 以流式细胞术仪检测、分选经DNA染料Hoechst 33342染色后MG-63中的SP细胞,采用CCK-8法检测顺铂对SP细胞与非侧群（non-SP）细胞的抑制率,并计算半数抑制浓度（IC₅₀）。荧光定量 PCＲ法检测SP细胞和non-SP细胞中 MRP、XRCC1、MGMT、ABCG2 mＲNA 的表达水平。结果 MG-63 细胞在细胞密度为9×10⁵个/ml、 Hoechst 33342 终质量浓度为5 μg/ml 时,MG-63 SP 细胞的比例最稳定,为（1.45±0.23）%,且细胞保持良好的活性。顺铂对SP细胞的IC₅₀为11.608 μg/ml,对non-SP细胞的IC50为6.876 μg/ml,两者比较差异有统计学意义（P<0.05）。MRP、XRCC1 、MGMT 和ABCG2 mＲNA 在 SP细胞中的表达分别是non-SP 细胞的 1.58 倍、1.61倍、2.36倍和3.14倍（P<0.05）。 结论 人骨肉瘤MG-63细胞中存在SP细胞亚群,与non-SP细胞相比,SP细胞对顺铂的耐药性更为明显,可能与其耐药基因MRP、XRCC1 、MGMT、ABCG2 mRNA的高水平表达有关。     

Identification of a cancer stem-like population in the Lewis lung cancer cell line

Objective: Although various human cancer stem cells (CSCs) have been defined, their applications are restricted to immunocompromised models. Developing a novel CSC model which could be used in immunocompetent or transgenic mice is essential for further understanding of the biomolecular characteristics of tumor stem cells. Therefore, in this study, we analyzed murine lung cancer cells for the presence of CSCs. Methods: Side population (SP) cells were isolated by fluorescence activated cell sorting, followed by serum-free medium (SFM) culture, using Lewis lung carcinoma cell (LLC) line. The self-renewal, differentiated progeny, chemosensitivity, and tumorigenic properties in SP and non-SP cells were investigated through in vitro culture and in vivo serial transplantation. Differential expression profiles of stem cell markers were examined by RT-PCR. Results: The SP cell fraction comprised 1.1% of the total LLC population. SP cells were available to grow in SFM, and had significantly enhanced capacity for cell proliferation and colony formation. They were also more resistant to cisplatin in comparison to non-SP cells, and displayed increased tumorigenic ability. Moreover, SP cells showed higher mRNA expression of Oct-4, ABCG2, and CD44. Conclusion: We identified SP cells from a murine lung carcinoma, which possess well-known characteristics of CSCs. Our study established a useful model that should allow investigation of the biological features and pharmacosensitivity of lung CSCs, both in vitro and in syngeneic immunocompetent or transgenic/knockout mice.     

膀胱癌细胞系T24侧群细胞的分离及初步鉴定

目的:检测和分选人类膀胱癌细胞系T24中的侧群（side population,SP）细胞,并初步鉴定其癌干细胞特性,为癌干细胞的分离纯化奠定基础。方法:采用荧光激活细胞分选（FACS）技术,分选得到T24细胞中的侧群细胞,并检测其比例。采用反转录聚合酶链反应（RT-PCR）技术检测侧群细胞中ABCG2的表达情况;继而将侧群细胞培养于无血清培养基中,观察形成悬浮肿瘤细胞球的能力。结果:流式细胞分选结果显示:T24细胞中侧群细胞的比例约为3.6%。和对应的母系T24细胞相比,T24侧群细胞的ABCG2表达增高。培养于无血清培养基中的侧群细胞成簇生长,并形成肿瘤细胞球。结论:人类膀胱癌细胞系T24中存在具有癌干细胞特性的侧群细胞。     

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。