喉癌侧群细胞生物学特性的研究
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
摘要
喉癌干细胞的研究目前只处在起始阶段,但这一概念为癌症的临床治疗提供了全新的视角,给人类战胜肿瘤带来了希望,对未来肿瘤研究的影响是不可估量的。
     本文以喉癌细胞系Hep-2为研究对象,采用荧光染料Hoechst33342对细胞染色后,应用流式分选技术检测分离SP和NSP亚群,应用RT-PCR、细胞免疫荧光、Western blot方法检测ABCG2分子在SP和NSP细胞中的表达,发现喉癌细胞系Hep-2中存在SP亚群,而且SP的表型与ABCG2密切相关。进一步通过观察分离后的SP和NSP细胞的生长形态、细胞周期分布、增殖能力、迁移能力、侵袭能力、粘附能力、克隆形成能力、对化疗药5-FU的耐药性等体外生物学特性及在免疫缺陷小鼠体内移植瘤成瘤能力来证实喉癌细胞系Hep-2的SP细胞是相对静止的,具有很强的增殖、分化、克隆形成、迁移、侵袭、成瘤及化疗耐药能力的干细胞样的细胞亚群。最后按照前期实验方法对40例临床喉癌标本原代培养细胞进行Hoechst33342染色后,通过流式细胞仪检测临床喉癌标本原代培养细胞中是否存在SP细胞,并探讨SP细胞与喉癌临床病理学因素的关系。经过研究发现检测的大部分喉癌标本中确实存在SP细胞亚群,SP细胞的比例与喉癌临床分期、病理分级相关。
     本实验进一步验证了肿瘤干细胞学说,探索了一种有意义的喉癌干细胞的分离方法,并初步确认了SP细胞与喉癌预后的关系,为今后喉癌干细胞的深层次研究奠定了初步的理论和实验基础。
The recurrence and metastasis is one of the primary causes for the death of patients with the malignant tumor, which is the biggest challenge for the tumor treatment. Until now the fundamental causes for the genesis, recurrence and metastasis of the tumor have not been identified, although some progress has been made in the study of biology.
     The conception of the tumor stem cell (TSC) has supplied a new thread for the study of the biological properties of the tumor, which make it possible for targeting the TSCs to kill them and preventing the recurrence and metastasis of the tumor. The conception has become the hot topic, but because most of the specific makers of the cells are unknown, the isolation and identification of the TSCs is quite difficult. The side population (SP)is a special type of the cell subpopulation, for which the isolation method is easy but mature. Therefore this method may bring a convenient way for the study of the TSCs.
     Many researchers have checked out the SP cells from various normal and tumor tissues. It was confirmed that compared with the non-SP (NSP)cells, SP cells from much tumor tissues possessed faster proliferation and self-renewal properties, they were more easier to form tumor in immunodeficient mice, and had stronger drug resistance, for which the stem cell characteristic cells were considered to be enriched in the SP cells. At present, the study of TSCs in laryngeal carcinoma is still in the primary stage. Our study investigated the biological properties of the SP cells from the laryngeal carcinoma cell line Hep-2 and the primary cultured laryngeal carcinoma cells, desiring to support a new approach and some experimental reference for the study of laryngeal TSCs.
     Part I:Detection and isolation of the SP cells from the laryngeal carcinoma cell line Hep-2
     Obsjective To detect and isolate the SP cells from laryngeal carcinoma cell line Hep-2, and characterize the generation mechanism of the phenotype of the SP cells. Methods The Hep-2 cells were cultured in vitro and observed under fluorescence microscope after dyed with Hoechst 33342.The SP cells and NSP cells were sorted by fluorescence-activated cell sorting(FACS).The SP and NSP cells were planted in DMEM with 10% FBS to observe the cell morphology. To detect and compare the expression of the mRNA and protein of ABCG2 between the SP and NSP cells, the assays of RT-PCR、cellular immunofluorescence、Western blot were performed. Results The SP cells existed in the laryngeal carcinoma cell line Hep-2,and the percentage of the Hoechst33342 negtive cells was (5.1±0.2)%.The proportion of the SP cells was (4.4±0.85)% sorted by FACS, which decreased to (0.63±0.31)% after the verapamil added. The two group cells showed the similar characteristics with Hep-2 cells after cultured in DMEM with 10% FBS. The expression of ABCG2 in SP cells was significantly higher than NSP cells(P<0.05).
     Conclusions SP cells do exist in laryngeal carcinoma cell line Hep-2, and ABCG2 is associated with the SP phenotype.
     Part II:Identification of the biological characteristics of cancer stem cell-like SP cells from laryngeal carcinoma cell line Hep-2
     Objective To explore the biological characteristics of cancer stem cell-like SP cells from laryngeal carcinoma cell line Hep-2. Methods The SP and NSP cells were cultured in vitro and observed under the inverted phase contrast microscope and the transmission electron microscope, the morphologic characteristics were compared between the two group cells. CCK-8 method was used to detect the proliferation capacity of the SP and NSP cells. The clone formation assay was carried out in the flat plates and the soft agar to observe the clone forming capacity of the SP and NSP cells. The two group cells were analysised by FASC to compare the differentiation potency and the cell cycle. To examine the invasion ability of SP and NSP cells, the matrigel invasion assay was performed. The transwell assay and the scarification test were used to evaluate the migration ability of the SP and NSP cells. The adherence property of the SP and NSP cells was detected by the method of CCK-8. To compare the tumorigenic activity, three numbers of SP and NSP cells were injected into the nude mice. CCK-8 assay was used to assess the proliferation inhibition of chemotherapy drug 5-FU for the two group cells. Results The SP cells depicted float colonies as proliferating, but the NSP cells did not generate the typical cell spheres observed under the inverted phase contrast microscope. Observed under the transmission electron microscope, the SP cells were integrated with big nucleolus and little cytoplasm, while the NSP cells showed the small pyknosis of the nucleolus, with much expanded endoplasmic reticulum and heterochromatin. In the CCK-8 proliferation assay, the absorbance the SP cells were higher than that of the NSP cells from the third cultured day. The ratio of clone formation of SP and NSP cells is (47.47±10.20)% and (4.98±1.41)% in the flat plates, and in the soft agar the ratio is (46.82±5.67)% and(12.53±3.51)% respectively, which demonstrated that the SP cells displayed the higher clone formation ratio than the NSP cells. In the differentiation potency assay by the FACS, the proportion of the sorted SP cells (4.2±0.47)% in the 14th day was similar to that of the first time sorting(4.4±0.85)%. Both the SP and NSP cells displayed a similar cell cycle distribution in the cell cycle assay. The SP cells depicted the higher migrating potency than the NSP cells in both the transwell assay and scarification test, of which the difference was significant(P< 0.05). The matrigel invasion assay showed that the SP cells that penetrated artificial basement membrane (39.04±4.78)% was higher than that of the NSP cells(25.16±4.63)% with significant differences(P<0.05). The adherence property assay of the SP and NSP cells in the CCK-8 test demonstrated that the SP cells owned the higher adherence property (P<0.05). Subcutaneous tumor formation needed as low as 1×103 SP cells inoculation in 3 of 5 mice, while as high as 1×105 NSP cells inoculation in 4 of 5 mice, which indicated that the tumorigenic activity of the SP cells were stronger than the NSP cells(P<0.05).The result of CCK-8 assay of proliferation inhibition showed that the chemotherapy drug 5-FU inhibited the proliferation of SP cells more obviously than the NSP cells. Conclusions The SP cells sorted from the laryngeal cancer cell line Hep-2 is a tumor stem cell-like subpopulation which displayed characteristics of high proliferative、clone formation、differentiation capacities, strong tumorigenic ability, and resistance of chemotherapy drugs.
     PartⅢ:Analysis of the SP cells in the primary laryngeal carcinoma cells
     Objective To detect the SP cells in the primary laryngeal carcinoma cells, and explore the associativity of the SP cells and the clinical pathological characteristics of the laryngeal carcinoma. Methods The primary laryngeal cancer cells from 40 cases of clinical specimens were harvested by the collagenase digestive method, and detected by the FACS for the side population. The associativity between the SP cells proportion of the primary laryngeal carcinoma cultured cells and the prognostic factors of the laryngeal carcinoma was analysised. Results The SP cells existed in most of the primary laryngeal carcinoma cells, and the average proportion of the SP cells from the 40 cases of laryngeal carcinoma specimens is (3.1±2.36)%.The SP cells were correlated with the clinical staging、pathological grading、metastasis of lymph node of the laryngeal carcinoma.Conclusion The SP cells exist in most primary laryngeal carcinoma specimen cultured cells. The SP cells were correlated with clinical pathological characteristics of the laryngeal carcinoma.
引文
[1]Marioni G, Marchese-Ragona R,Cartei G,et al.Current opinion in diagnosis and treatment of laryngeal carcinoma[J].Cancer Treat Rev,2006,32(7):504-515.
    [2]刘巍巍,曾宗渊,谢汝华,等.喉癌治疗后原发灶复发的手术救援[J].肿瘤,2003,3(5):417-419.
    [3]Reya T, Morrison SJ, Clarke MF, et al. Stem cells, cancer, and cancer stem cells [J].Nature,2001,414(6859):105-111.
    [4]Altaba AR. Therapeutic inhibition of hadgehog-GLI signaling in cancer: epithelial, stromal, or stem cell targets [J]?Cancer Cell,2008,14(4):281-283.
    [5]Lapidot T, Sirard C, Vormoor J, et al. A cell initiating human acute myeloid leukaemia after transplantation into SCID mice [J]. Nature,1994,367(6464):645-648.
    [6]Al-Hajj M, Clarke MF.Self-renewal and solid tumor stem cells [J]. Oncogene, 2004,23 (43):7274-7282.
    [7]Ignatova TN, Kukekov VG, Laywell ED, et al. Human corticalglial tumors contain neural stem-like cells expressing astroglial and neuronal markers in vitro [J]. Glia,2002,39(3):193-206.
    [8]FangD, Ngnyen TK, LeishearK, et al. A tumorigenic subpopulation with stem cell properties in melanomas [J]. Cancer Res,2005,65(20):9382-9337.
    [9]Lobo NA. Shimono Y, Qian D, et al. The biology of cancer stem cells [J]. Annu Rev Cell Dev Biol,2007,23:675-699.
    [10]Prince ME, Sivanandan R, Kaczorowski A, et al. Identification of a subpopulation of cells with cancer stem cell properties in head and neck squamous cell carcinoma[J]. Proc Natl Acad Sci USA,2007,104(3):973-978.
    [11]Shachaf CM, Kopelman AM, Arvanitis C, et al. MYC inactivation uncovers pluripotent differentiation and tumour dormancy in hepatocellular cancer [J]. Nature,2004,431(7012):1112-1117.
    [12]Kim CF, Jackson EL, Woolfenden AE, et al. Identification of bronchioalveolar stem cells in normal lung and lung cancer [J]. Cell,2005,121(6):823-835.
    [13]Maitland NJ, Collins A.A tumour stem cell hypothesis for the origins of prostate cancer [J]. BJU Int,2005,96(9):1219-1223.
    [14]Dalerba P,Dylla SJ, Park IK,et al. Phenotypic characterization of human colorectal cancer stem cells [J].Proc Natl Acad Sci USA,2007,104(24):10158-10163.
    [15]Singh SK, Hawkins C, Clarke ID, et al. Idendification of human brain tumor initiating cells [J].Nature,2004,432(7015):396-401.
    [16]Goodell MA, Brose K, Paradis G, et al. Isolation and functional properties of murine hematopoietic stem cells that are replicating in vivo[J].J Exp Med,1996, 183(4):1797-1806.
    [17]Graham SM, Jorgensen HG, Allan E, et al. Primitive, quiescent, philadelphia-positive stem cells from patients with chronic myeloid leukemia are insensitive to ST1571 in vitro [J]. Blood,2002,99(1):319-325.
    [18]Wulf GG, Wang RY, Kuehnle I, et al. A leukemic stem cell with intrinsic drug efflux capacity in acutemyeloid leukemia [J]. Blood,2001,98(4):1166-1173.
    [19]Liu BY, McDermott SP, Khwaja SS, et al. The transforming activity of Wnt effectors correlates with their ability to induce the accumulation of mammary progenitor cells [J]. Proc Natl Acad Sci USA,2004,101(12):4158-4163.
    [20]Kondo T, Setoguchi T, Taga T. Persistence of a small subpopulation of cancer stem-like cells in the C6 glioma cellline[J].Proc Natl Acad Sci USA,2004, 101(3):781-786.
    [21]Ho MM, Ng AV,Lam S,et al. Side population in human lung cancer cell lines and tumors is enriched with stem-like cancer cells [J]. Cancer Res,2007,67(10): 4827-4833.
    [22]Haraguchi N, Utsunomiya T, Inoue H, et al. Characterization of a side population of cancer cells from human gastrointestinal system [J]. Stem Cells, 2006,24(3):506-513.
    [23]Mitsutake N, Iwao A, Nagai K, et al. Characterization of side population in thyroid cancer cell lines:cancer stem-like cells are enriched partly but not exclusively [J]. Endocrinology,2007,148(4):1797-1803.
    [24]Wang J, Guo LP, Chen LZ, et al. Identification of cancer stem cell-like side population cells in human nasopharyngeal carcinoma cell line [J]. Cancer Res, 2007,67(8):3716-3724.
    [25]Zhang P, Zhang Y, Mao L, et al. Side population in oral squamous cell carcinoma possesses tumor stem cell phenotypes [J]. Cancer Lett,2009,277(2):227-234.
    [26]Wan G, Zhou L, Xie M, et al. Characterization of side population cells from laryngeal cancer cell lines [J]. Head Neck,2010,32(10):1302-1309.
    [1]Reya T, Morrison SJ, Clarke MF, et al. Stem cells, cancer, and cancer stem cells [J]. Nature,2001,414(6859):105-111.
    [2]Cohnheim J. Ueber entzundung und eiterung [J]. Path Anat Physiol Klin Med, 1867,40:1-79.
    [3]Cohnheim J. Congenitales, quergestreiftes Muskelsarkon der Nireren [J]. Virchows Arch,1875,65:64.
    [4]Makino S. The role of tumor stem cells in regrowth of the tumor following drastic applications [J]. Acta Unio Int Contra Cancrum,1959,15 (Suppll): 196-198.
    [5]Hamburger AW, Salmon SE.Primary bioassay of human tumor stem cells [J].Science,1977,197 (4302):461-463.
    [6]Bonnet D, Dick JE. Human acutemyeloid leukemia is organized as a hierarchy that originates from a primitive hematopoietic cell [J]. Nature Medicine,1997, 3(7):730-737.
    [7]Al-Hajj M, Wicha MS, Benito-Hernandez A, et al. Prospective identification of tumorigenic breast cancer cells[J]. Proc Natl Acad Sci USA,2003,100(7): 3983-3988.
    [8]Sun ZG, Huang SD, Zhang BR, et al. Isolation and identification of cancer stem cells from human esophageal carcinoma [J].Cell,2009,89(5):291-295.
    [9]Yang ZF, Ho DW, Ng MN, et al. Significance of CD90+ cancer stem cells in human liver cancer[J].Cancer Cell,2008,13(2):153-166.
    [10]Li C, Heidt DG, Daler BA, et al. Identification of pancreatic cancer stem cells [J]. Cancer Res,2007,67(3):1030-1037
    [11]Cheshier SH, Kalani MY, Lim M, et al. A neurosurgeon's guide to stem cells, cancer stem cells, and brain tumor stem cells [J].Neurosurgery,2009,65(2): 237-249; discussion 249-250; quiz N6.
    [12]Ricci-Vitiani L, Lombardi DG, Pilozzi E, et al. Identification and expansion of human colon-cancer-initiating cells [J]. Nature,2007,445(7123):111-115.
    [13]Prince ME, Sivanandan R, Kaczorowski A, et al. Identification of a subpopulation of cells with cancer stem cell properties in head and neck squamous cell carcinoma [J]. Proc Natl Acad Sci USA,2007,104(3):973-978.
    [14]Collins AT, Berry PA, Hyde C, et al. Prospective identification of tumorigenic prostate cancer stem cells [J]. Cancer Res,2005,65(23):10946-10951.
    [15]Wang JC, Dick JE. Cancer stem cells:lessons from leukemia [J]. Trends Cell Biol,2005,15(9):494-501.
    [16]Dick JE. Stem cell concepts renew cancer research [J]. Blood,2008,112(13): 4793-4807.
    [17]Bjerkvig R, Tysnes BB, Aboody KS, et al. Opinion:the origin of the cancer stem cell:current controversies and new insights [J]. Nat Rev Cancer,2005,5(11): 899-904.
    [18]Clarke MF, Dick JE, Dirks PB,et al. Cancer stem cells-perspectives on current status and future directions:AACR workshop on cancer stem cells [J]. Cancer Res,2006,66(19):9339-9344.
    [19]Ren X, Hu B, Colletti L.Stem cell factor and its receptor, c-kit, are important for hepatocyte proliferation in wild-type and tumor necrosis factor receptor-1 knockout mice after 70% hepatectomy[J].Surgery,2008,143(6):790-802.
    [20]Veeraraghavalu K, Subbaiah VK, Srivastava S, et al. Complementation of human papilloma virus type 16 E6 and E7 by Jagged 1-specific Notch 1-phosphatidylinositol 3-kinase signaling involves pleiotropic oncogenic functions independent of CBF1;Su(H); Lag-1 activation [J]. J Virol,2005, 79(12):7889-7898.
    [21]Ponti D, Costa A, Zaffaroni N, et al. Isolation and in vitro propagation of tumorigenic breast cancer cells with stem/progenitor cell properties [J]. Cancer Res,2005,65(13):5506-5511.
    [22]刘新垣.癌症靶向治疗的新趋势[J].中华肿瘤防治杂志,2006,13(18):1361-1364.
    [23]Espada J, Calvo MB, Diaz-Prado S,et al.Wnt signaling and cancer stem cells[J]. Clin Transl Oncol,2009,11(7):411-427.
    [24]Zhang XP, Zheng G, Zou L, et al. Notch activation promotes cell proliferation and the formation of neural stem cell-like colonies in human glioma cells [J]. Mol Cell Biochem,2008,307(1-2):101-108.
    [25]Guzman ML, Swiderski CF, Howard DS, et al. Preferential induction of apoptosis for primary human leukemic stem cells [J]. Proc Natl Acad Sci USA, 2002,99(25):16220-16225.
    [26]Yu F, Yao H, Zhu P, et al. Let-7 regulates self renewal and tumorigenicity of breast cancer cells [J].Cell,2007,131(6):1109-1123.
    [27]Guan Y, Gerhard B, Hogge DE. Detection, isolation, and stimulation of quiescent primitive leukemic progenitor cells from patients with acute myeloid leukemia(AML)[J]. Blood,2003,101(8):3142-3149.
    [28]Robey RW, Polgar O, Deeken J, et al. ABCG2:determining its relevance in clinical drug resistance [J]. Cancer Metastasis Rev,2007,26(1):39-57.
    [29]Liu G, Yuan X, Zeng Z, et al. Analysis of gene expression and chemoresistance of CD133+ cancer stem cells in glioblastoma [J]. Mol Cancer,2006,5:67.
    [30]Pearce DJ, Taussig D, Simpson C, et al. Characterization of cells with a high aldehyde dehydrogenase activity from cord blood and acute myeloid leukemia samples [J]. Stem Cells,2005,23(6):752-760.
    [31]Jiang F, Qiu Q, Khanna A, et al. Aldehyde dehydrogenase 1 is a tumor stem cell-associated marker in lung cancer [J]. Mol Cancer Res,2009,7(3):330-338.
    [32]Pankov R, Cukierman E, Clark K, et al. Specific betal integrin site selectively regulates Akt/protein kinase B signaling via local activation of protein phosphatase 2A [J]. J Biol Chem,2003,278(20):18671-18681.
    [33]Pim D, Massimi P, Dilworth SM, et al. Activation of the protein kinase B pathway by the HPV-16 E7 oncoprotein occurs through a mechanism involving interaction with PP2A[J].Oncogene,2005,24 (53):7830-7838.
    [34]Sheridan C, Kishimoto H, Fuchs RK, et al. CD44+/CD24-breast cancer cells exhibit enhanced in properties:an early step necessary for metastasis [J].Breast Cancer Res,2006,8(5):R59.
    [35]Li F, Tiede B, Massague J et al. Beyond tumorigenesis:cancer stem cells in metastasis[J]. Cell Res,2007,17(1):3-14.
    [36]Jordan CT, Guzman ML, Noble M. Cancer stem cells [J]. N Engl J Med,2006, 355(12):1253-1261.
    [37]Shackleton M, Vaillant F, Simpson KJ, et al. Generation of a functional mammary gland from a single stem cell [J]. Nature,2006,439 (7072):84-88.
    [38]Jaiswal S, Traver D, Miyamoto T, et al. Expression of BCR/ABL and BCL-2 in myeloid progenitors leads to myeloid leukemias [J]. Proc Natl Acad Sci USA, 2003,100(17):10002-10007.
    [39]Vescovi AL, Galli R, Reynolds BA. Brain tumor stem cells [J]. Nature Reviews Cancer,2006,6(6):425-436.
    [40]Wagers AJ, Weissman IL. Plasticity of adult stem cells [J]. Cell,2004,116(5): 639-648.
    [41]RizviA Z, Swain JR, Davies PS, et al. Bone marrow-derived cells fuse with normal and transformed intestinal stem cells [J].Proc Natl Acad Sci USA,2006, 103(16):6321-6325.
    [42]Singh SK, Hawkins C, Clarke ID, et al. Identification of human brain tumour initiating cells [J]. Nature,2004,432(7015):396-401.
    [43]Graham SM, Jorgensen HG, Allan E, et al. Primitive, quiescent, philadelphia-positive stem cells from patients with chronic myeloid leukemia are insensitive to STI571 in vitro [J]. Blood,2002,99(1):319-925.
    [44]Wulf GG, Wang RY, Kuehnle I,et al. A leukemic stem cell with intrinsic drug efflux capacity in acutemyeloid leukemia [J]. Blood,2001,98(4):1166-1173.
    [45]Liu BY, McDermott SP, Khwaja SS, et al. The transforming activity of Wnt effectors correlates with their ability to induce the accumulation of mammary progenitor cells [J]. Proc Natl Acad Sci USA,2004,101(12):4158-4163.
    [46]Kondo T, Setoguchi T, Taga T. Persistence of a small subpopulation of cancer stem-like cells in the C6 glioma cell line[J].Proc Natl Acad Sci USA,2004; 101(3):781-786.
    [47]Ho MM, Ng AV, Lam S, et al. Side population in human lung cancer cell lines and tumors is enriched with stem-like cancer cells [J].Cancer Res,2007,67(10): 4827-4833.
    [48]Haraguchi N, Utsunomiya T, Inoue H, et al. Characterization of a side population of cancer cells from human gastrointestinal system [J]. Stem Cells, 2006,24(3):506-513.
    [49]Challen GA, Little MH. A side order of stem cells:the SP phenotype [J].Stem Cells,2006,24(1):3-12.
    [50]Zhang HB, Ren CP, Ye L, et al. Indentification of label-retaining cells in nasopharyngeal epithelial and nasopharyngeal carcinoma tissues [J].Histochem Cell Biol,2007,127 (3):347-354.
    [51]Zhang J, Niu C, Ye L, et al. Identification of the haematopoietic stem cell niche and control of the niche size [J].Nature,2003,425(6960):836-841.
    [52]Corti S, Locatelli F, Papadimitriou D, et al. Identification of a primitive brain-derived neural stem cell population based on aldehyde dehydrogenase activity [J]. Stem Cells,2006,24(4):975-985.
    [53]Lobl NA, Shimono Y, Qian D, et al. The biology of cancer stem cells [J].Annu Rev Cell Dev Biol,2007,23:675-699.
    [54]Levran O, O'Hara K, Peles E, et al. ABCB1 (MDR1) genetic variants are associated with methadone doses required for effective treatment of heroin dependence[J]. Hum Mol Genet,2008,17(14):2219-2227.
    [55]Neethan AL, Yohei S, Dalong Q, et al. The biology of cancer stem cells [J].Annu Rev Cell Dev Biol,2007, 11(23):675-699.
    [56]Spillane JB, Henderson MA. Cancer stem cells:a review [J].ANZ J Surg,2007, 77(6):464-468.
    [57]Dick JE. Breast cancer stem cells revealed [J]. Proc Natl Acad Sci USA,2003, 100(7):3547-3549.
    [58]Al-Hajj M, Becker MW, Wicha M,et al. Therapeutic implications of cancer stem cells [J]. Curr Opin Genet Dev,2004,14(1):43-47.
    [59]Lapidot T, Sirard C, Vormoor J, et al. A cell initiating human acute myeloid leukaemia after transplantation into SCID mice [J]. Nature,1994,367(6464):645-648.
    [60]Miyamoto T, Weissman IL, Akashi K. AML1/ETO2 expressing non-leukemic stem cells in acute myelogenous leukemia with 8;21 chromosomal translocation [J]. Proc Natl Acad Sci USA,2000,97(13):7521-7526.
    [61]Cox CV, Evely RS, Oakhill A, et al. Characterization of acute lymphoblastic leukemia progenitor cell [J]. Blood,2004,104(9):2919.
    [62]Abkowitz JL, Chen J. Studies of c-MpI function distiuguish the replication of hematopoietic stem cell from the expansion of differentiating clones [J]. Blood, 2007,109(12):5186-5190.
    [63]Nishida H, Yamazaki H, Yamada T, et al. CD9 correlates with cancer stem cell potentials in human B-acute lymphoblastic leukemia cells [J].Biochem Biophys Res commun,2009,382(1):57-62.
    [64]Du X, HOM, Pastan I. New immunotoxins targeting CD 123, a stem cell antigen on acute myeloid leukemia cells [J]. J Immunother,2007,30(6):607-613.
    [65]Hosen N, Park CY, Tatsum iN, et al. CD96 is a leukemia stem cell-specific marker in human acute myeloid leukemia [J]. Proc Natl Acad Sci USA,2007, 104(26):11008-11013.
    [66]Al-Hajj M, Clarke MF. Self-renewal and solid tumor stem cells [J]. Oncogene, 2004,23(43):7274-7282.
    [67]Ignatova TN, Kukekov VG, Laywell ED, et al. Human corticalglial tumors contain neural stem-like cells expressing astroglial and neuronal markers in vitro [J]. Glia,2002,39(3):193-206.
    [68]Singh SK, Clarke ID, Terasaki M, et al. Identification of a cancer stem cell in human brain tumors [J].Cancer Res,2003,63(18):5821-5828
    [69]邓永文,方加胜,李茗初,等.胶质瘤中肿瘤干细胞的分离、培养及鉴定[J].中国现代医学杂志,2005,15(16):2449-2452.
    [70]Zhou L, Wei X, Cheng L, et al. CD 133, one of the markers of cancer stem cells in Hep-2 cell line[J]. Laryngoscope,2007,117(3):455-460.
    [71]Kim CF, Jackson EL, Woolfenden AE, et al. Identification of brochioalveolar stem cells in normal lung and lung cancer [J]. Cell,2005,121(6):823-835.
    [72]O'Brien CA, Pollett A, Gallinger S, et al. A human colon cancer cell capable of initiating tumour growth in immunodeficient mice [J]. Nature,2007,445(7123): 106-110.
    [73]Dalerba P, Dylla SJ, Park IK, et al. Phenotypic characterization of human colorectal cancer stem cells [J].Proc Natl Acad Sci USA,2007,104(24):10158-10163.
    [74]Vormoor J, Baersch G, Decker S, et al. Establishment of an in vivo model for pediatric ewing tumors by transplantation into NOD/SCID mice [J]. Pediatr Res, 2001,49 (3):332-341.
    [75]Fang D, Ngnyen TK, LeishearK, et al. A tumorigenic subpopulation with stem cell properties in melanomas [J]. Cancer Res,2005,65(20):9382-9337.
    [76]Shachaf CM, Kopelman AM, Arvanitis C, et al. MYC inactivation uncovers pluripotent differentiation and tumour dormancy in hepatocellular cancer [J].Nature,2004,431(7012):1112-1117.
    [77]Maitland NJ, Collins A. A tumour stem cell hypothesis for the origins of prostate cancer [J].BJU Int 2005,96(9):1219-1223.
    [78]Altaba AR. Therapeutic inhibition of hadgehog-GLI signaling in cancer: epithelia, stromal, or stem cell targets [J]?Cancer Cell,2008,14(4):281-283.
    [79]Romer JT, Kimura H, Magdaleno S, et al. Suppression of the Shh pathway using a small molecule inhibitor eliminates medulloblastoma in Ptcl (+/-) p53 (-/-) mice [J]. Cancer Cell,2004,6(3):229-240.
    [80]Fan X, Matsui W, Khaki L, et al. Notch pathway inhibition depletes stem-like cells and blocks engraftment in embryonal brain tumors [J]. Cancer Res,2006, 66(15):7445-7452.
    [81]Jin XC, Bo LL, Xiang Z. How powerful is CD133 as a cancer stem cell marker in brain tumors [J]?Cancer Treat Rev,2009,35(5):403-408.
    [82]谢渭芬,许文萍.肝细胞癌的诱导分化治疗[J].中国肿瘤生物治疗杂志,2010,17(4):363-367.
    [83]Ohno R, Asou N, Ohnishi K. Treatment of acute promyelocytic leukemia:strategy toward further increase of cure rate [J]. Leukemia,2003,17(8):1454-1463.
    [84]Gupta PB, Onder TT, Jiang G Identification of selective inhibitors of cancer stem cells by high-throughput screening [J]. Cell,2009,138(4):645-659.
    [85]Clarke MF, Fuller M. Stem cells and cancer:two faces of eve [J]. Cell,2006, 124(6):1111-1115.
    [1]Goodell MA, Rosenzweig M, Kim H, et al. Dye efflux studies suggest that hematopoietic stem cells expressing low or undetectable levels of CD34 antigen exist in multiple species[J].Nat Med,1997,3(12):1337-1345.
    [2]Hadnagy A,Gaboury L, Beaulieu R, et al. SP analysis may be used to identify cancer stem cell populations [J]. Exp Cell Res,2006,312(19):3701-3710.
    [3]Goodell MA, Brose K, Paradis G, et al. Isolation and functional properties of murine hematopoietic stem cells that are replicating in vivo[J]. J Exp Med 1996,183 (4):1797-1806.
    [4} Zhou S, Schuetz JD, Bunting KD, et al. The ABC transporter Bcrpl/ABCG2 is expressed in a wide variety of stem cells and is a molecular determinant of the side-population phenotype [J].Nat Med,2001,7(9):1028-1034.
    [5]Habich A, Jurga M, Markiewicz I, et al. Early appearance of stem/progenitor cells with neural-like characteristics in human cord blood mononuclear fraction cultured in vitro [J]. Exp Hematol,2006,34(7):914-925.
    [6]Zhang S, Uchida S, Inoue T,et al. Side population (SP) cells isolated from fetal rat calvaria are inriched for bone, cartilage, adipose tissue and neural progenitors [J].Bone,2006,38(5):662-670.
    [7]Mitsutake N, Iwao A, Nagai K, et al. Characterization of side population in thyroid cancer cell lines:cancer stem-like cells are enriched partly but not exclusively [J]. Endocrinology,2007,148 (4):1797-1803.
    [8]Challen GA, Little MH. A side order of stem cells:the SP phenotype [J]. Stem Cells,2006,24(1):3-12.
    [9]Guo Y, Follo M,Geiger K, et al. Side-population cells from different precursor compartments [J].J Hematother Stem Cell Res,2003,12(1):71-82.
    [10]Uchida N, Fujisaki T, Eaves AC,et al. Transplantable hematopoietic stem cells in human fetal liver have a CD34 (+) side population (SP) phenotype [J]. J Clin Invest,2001,108(7):1071-1077.
    [11]Preffer FI, Dombkowski D, Sykes M,et al. Lineage-negative side-population (SP) cells with restricted hematopoietic capacity circulate in normal human adult blood:immunophenotypic and functional characterization [J]. Stem Cells,2002, 20(5):417-427.
    [12]Asakura A, Rudnicki MA. Side population cells from diverse adult tissues are capable of in vitro hematopoietic differentiation [J]. Exp Hematol,2002, 30(11):1339-1345.
    [13]Kim M, Morshead CM.Distinct populations of forebrain neural stem and progenitor cells can be isolated using side-population analysis [J]. J Neurosci, 2003,23(33):10703-10709.
    [14]Murayama A, Matsuzaki Y, Kawaguchi A,et al. Flow cytometric analysis of neural stem cells in the developing and adult mouse brain [J]. J Neurosci Res. 2002,69(6):837-847.
    [15]Majka SM, Jackson KA, Kienstra KA,et al. Distinct progenitor populations in skeletal muscle are bone marrow derived and exhibit different cell fates during vascular regeneration [J]. J Clin Invest,2003,111(1):71-79.
    [16]Falciatori I, Borsellino G, Haliassos N,et al. Identification and enrichment of spermatogonial stem cells displaying side-population phenotype in immature mouse testis [J]. FASEB J,2004,18(2):376-378.
    [17]Watanabe K, Nishida K, Yamato M, et al. Human limbal epithelium contains side population cells expressing the ATP-binding cassette transporter ABCG2 [J]. FEBS Lett,2004,565(1-3):6-10.
    [18]Lechner A, Leech CA, Abraham EJ,et al. Nestin-positive progenitor cells derived from adult human pancreatic islets of langerhans contain side population (SP) cells defined by expression of the ABCG2 (BCRP1) ATP-binding cassette transporter [J]. Biochem Biophys Res Commun,2002,293(2):670-674.
    [19]Giangreco A, Shen H, Reynolds SD, et al. Molecular phenotype of airway side population cells [J]. Am J Physiol Lung Cell Mol Physiol,2004,286(4):L624-630.
    [20]Kondo T, Setoguchi T, Taga T. Persistence of a small subpopulation of cancer stem-like cells in the C6 glioma cell line [J]. Proc Natl Acad Sci USA,2004, 101(3):781-786.
    [21]Szotek PP, Pieretti-Vanmarcke R, Masiakos PT, et al. Ovarian cancer side population defines cells with stem cell-like characteristics and mullerian inhibiting substance responsiveness [J]. Proc Natl Acad Sci USA,2006,103(30):11154-11159.
    [22]Chiba T, Kita K, Zheng Y W, et al. Side population purified from hepatocellular carcinoma cells harbors cancer stem cell-like properties [J]. Hepatology,2006, 44(1):240-251.
    [23]Hirschmann-Jax C, Foster AE, Wulf GG, et al. A distinct"side population"of cells with high drug efflux capacity in human tumor cells [J].Proc Natl Acad Sci USA,2004,101(39):14228-14233.
    [24]Wang J, Guo L P, Chen L Z, et al. Identification of cancer stem cell-like side population cells in human nasopharyngeal carcinoma cell line [J]. Cancer Res, 2007,67(8):3716-3724.
    [25]Ho MM, Ng AV, Lam S, et al. Side population in human lung cancer cell lines and tumors is enriched with stem-like cancer cells [J]. Cancer Res,2007, 67(10):4827-4833.
    [26]Haraguchi N, Utsunomiya T, Inoue H, et al. Characterization of a side population of cancer cells from human gastrointestinal system [J]. Stem Cells, 2006,24(3):506-513.
    [27]Wu C, Wei Q, Utomo V, et al. Side population cells isolated from mesenchymal neoplasms have tumor initiating potential[J]. Cancer Res,2007,67(17):8216-8222.
    [28]Setoguchi T, Taga T, Kondo T, et al. Cancer stem cells Persist in many cancer Cell lines [J].Cell Cycle,2004,3(4):414-415.
    [29]de Jonge-Peeters SD, Kuipers F, de Vries EG, et al. ABC transporter expression in hematopoietic stem cells and the role in AML drug resistance [J]. Crit Rev Oncol Hematol,2007,62(3):214-226.
    [30]Dean M, Fojo T, Bates S. Tumour stem cells and drug resistance [J]. Nat Rev Cancer,2005,5(4):275-284.
    [31]Rocchi E, Khodjakov A, Volk EL,et al. The product of the ABC half-transporter gene ABCG2 (BCRP/MXR/ABCP) is expressed in the plasma membrane [J]. Biochem Biophys Res Commun,2000,271(1):42-46.
    [32]Martin CM, Meeson AP, Robertson SM, et al. Persistent expression of the ATP-binding cassette transporter, ABCG2, identifies cardiac SP cells in the developing and adult heart [J]. Dev Biol,2004,265(1):262-275.
    [33]Krishnamurthy P, Schuetz JD. Role of ABCG2/BCRP in biology and medicine [J]. Annu Rev Pharmacol Toxicol,2006,46:381-410.
    [34]Montanaro F, Liadaki K, Schienda J, et al. Demystifying SP cell purification: viability, yield, and phenotype are defined by isolation parameters [J]. Exp Cell Res,2004,298(1):144-154.
    [35]Jackson KA, Mi T, Goodell MA. Hematopoietic potential of stem cells isolated from murine skeletal muscle [J]. Proc Natl Acad Sci USA,1999,96(25):14482-14486.
    [36]Horsley V, Aliprantis AO, Polak L,et al. NFATcl balances quiescence and proliferation of skin stem cells [J]. Cell,2008,132(2):299-310.
    [37]Benchaouir R, Rameau P, Decraene C, et al. Evidence for a resident subset of cells with SP phenotype in the C2C12 myogenic line:a tool to explore muscle stem cell biology [J]. Exp Cell Res,2004,294(1):254-268.
    [38]Clarke MF, Dick JE, Dirks PB, et al. Cancer stem cells-perspectives on current status and future directions:AACR workshop on cancer stem cells [J]. Cancer Res,2006,66 (19):9339-9344.
    [39]Robey RW, Polgar O, Deeken J, et al. ABCG2:determining its relevance in clinical drug resistance. Cancer Metastasis Rev,2007,26(1):39-57.
    [40]Robey RW, Polgar O, Deeken J, et al. Identification of cancer stem cell-like side population cells in human nasopharyngeal carcinoma cell line[J].Cancer Res, 2007,67(8):3716-3724.
    [41]Telford WG, Frolova EG. Discrimination of the hoechst side population in mouse bone marrow with violet and near-ultraviolet laser diodes [J].Cytometry, 2004,57(1):45-52.
    [42]Shi GM, Xu Y, Fan J, et al. Identification of side population cells inhuman hepatocellular carcinoma cell lines with stepwise metastatic potentials [J]. J Cancer Res Clin Oncol,2008,134(11):1155-1163.
    [43]Brown MD, Gilmore PE, Hart CA, et al. Characterization of benign and malignant prostate epithelial Hoechst33342 side populations [J]. Prostate,2007, 67(13):1384-1396.
    [44]黄盛松,吴登龙,阂志慧,等.膀胱癌干细胞样侧群细胞的分选与鉴定[J]. 中华泌尿外科杂志,2008,29(1):44-48.
    [45]Sung JM, Cho HJ, Yi H, et al. Characterization of a stem cell population in lung cancer A549 cells [J]. Biochem Biophys Res Commun,2008,371(1):163-167.
    [46]Yajima T, Oehiai H, Uchiyama T, et al. Resistance to cytotoxic chemotherapy-induced apoptosis in side population cells of human oral squamous cell carcinoma cell line Ho-1-N-1 [J]. hit J Oncol,2009,35(2):273-280.
    [47]Wan G, Zhou L, Xie M, et al. Characterization of side population cells from laryngeal cancer cell lines [J]. Head Neck,2010,32(10):1302-1309.
    [48]Chen JS, Pardo FS, Wang-Rodriguez J, et al. EGFR regulates the side population in head and neck squamous cell carcinoma [J]. Laryngoscope,2006,116(3):401-406.
    [49]Fang D, Nguyen TK, Leishear K, et al. A tumorigenic subpulation with stem cell properties in melanomas [J]. Cancer Res,2005,65(20):9328-9337.
    [50]Fried J, Doblin J, Takamoto S, et al. Effects of Hoechst 33342 on survival and growth of two tumor cell lines and on hematopoietically normal bone marrow cells [J]. Cytometry,1982,3(1):42-47.
    [51]Zheng X, Shen G, Yang X, et al. Most C6 cells are cancer stem cells:evidence from clonal and population analyses [J]. Cancer Res,2007,67(8):3691-3697.
    [52]Zhou J, Wulfkuhle J, Zhang H, et al. Activation of the PTEN/Mtor/STAT3 pathway in breast cancer stem-like cells is required for viability and maintenance [J]. Proc Natl Acad Sci USA,2007,104 (41):16158-16163.
    [53]Sales-Pardo I, Avendano A, Martinez-Munoz V, et al. Flow cytometry of the side population:tips & trieks [J].Cell Oncol,2006,28(1-2):37-53.
    [54]Morita Y, Ema H, Yamazaki S, et al. Non-side-population hematopoietic stem cells in mouse bone marrow[J]. Blood,2006,108(8):2850-2856.
    [55]Patrawala L, Calhoun T, Schneider-Broussard R, et al. Side population is enriched in tumorigenic, stem-like cancer cells, whereas ABCG2+ and ABCG2- cancer cells are similarly tumorigenic [J]. Cancer Res,2005,65(14):6207-6219.
    [56]Triel C, Vestergaard ME, Bolund L, et al. Side population cells in human and mouse epidermis lack stem cell characteristics [J]. Exp Cell Res,2004,295(1):79-90.
    [57]Liehtenauer UD, Shapiro I, Geiger K, et al. Side population does not define stem cell-like cancer cells in the adrenocortical carcinoma cell line NCI h295R [J]. Endocrinology,2008,149(3):1314-1322.
    [1]Wang J, Guo LP, Chen LZ, et al. Identification of cancer stem cell-like side population cells in human nasopharyngeal carcinoma cell line [J]. Cancer Res, 2007,67(8):3716-3724.
    [2]Goodell MA, Brose K, Paradis G, et al. Isolation and functional properfies of murine hematopoietic stem cells that are replicating in vivo [J]. J Exp Med,1996, 183(4):1797-1806.
    [3]Zhou S, Schuetz JD, Bunting KD, et al. The ABC transporter Bcrpl/ABCG2 is expressed in a wide variety of stem cells and is a molecular determinant of the side-population phenotype [J]. Nat Med,2001,7(9):1028-1034.
    [4]Habich A, Jurga M, Markiewicz I, et al. Early appearance of stem/progenitor cells with neural-like characteristics in human cord blood mononuclear fraction cultured in vitro [J].Exp Hematol,2006,34(7):914-925.
    [5]Zhang S,Uchida S,Inoue T,et al. Side population (SP) cells isolated from fetal rat calvaria are enriched for one, cartilage, adipose tissue and neural progenitors [J].Bone,2006,38(5):662-670.
    [6]Challen GA, Little MH. A side order of stem cells:the SP phenotype [J].Stem Cells,2006,24(1):3-12.
    [7]Hirschmann-Jax C, Foster AE, Wulf GG, et al. A distinct "side population" of cells with high drug efflux capacity in human tumor cells [J].Proc Natl Acad Sci USA,2004,101(39):14228-14233.
    [8]Mitsutake N, Iwao A, Nagai K, et al. Characterization of side population in thyroid cancer cell lines:cancer stem-like cells are enriched partly but not exclusively [J]. Endocrinology,2007,148(4):1797-1803.
    [9]Kondo T, Setoguchi T, Taga T, et al. Persistence of a small subpopulation of cancer tem-like cells in the C6 glioma cell line [J].Proc Natl Acad Sci USA,2004, 101(3):781-786.
    [10]Szotek PP, Pieretti-Vanmarcke R, Masiakos PT, et al. Ovarian cancer side population defines cells with stem cell-like characteristics and mullerian inhibiting substance responsiveness [J]. Proc Natl Acad Sci USA,2006,103(30): 11154-11159.
    [11]Wan G, Zhou L, Xie M, et al. Characterization of side population cells from laryngeal cancer cell lines [J].Head Neck,2010,32 (10):1302-1309.
    [12]Telford WG. Analysis of UV-excited fluorochromes by flow cytometry using near-ultraviolet laser diodes[J].Cytometry A,2004,61(1):9-17.
    [13]Zhang P, Zhang Y, Mao L, et al. Side population in oral squamous cell carcinoma possesses tumor stem cell phenotypes [J].Cancer Lett,2009,277(2):227-234.
    [1]Reya T, Morrison SJ, Clarke MF, et al. Stem cells, cancer, and cancer stem cells[J]. Nature,2001,414(6859):105-111.
    [2]Challen GA, Bertoncello I, Deane JA, et al. Kidney side population reveals multilineage potential and renal functional capacity but also cellular heterogeneity [J]. J Am Soc Nephrol,2006,17(7):1896-1912.
    [3]Hadnagy A,Gaboury L, Beaulieu R, et al. SP analysis may be used to identify cancer stem cell populations [J]. Exp Cell Res,2006,312(19):3701-3710.
    [4]Challen GA, Little MH.A side order of stem cells:the SP phenotype [J]. Stem Cells,2006,24(1):3-12.
    [5]Mahller YY, Williams JP, Balrd WH, et al. Neuroblastoma cell lines contain pluripotent tumor initiating cells that are susceptible to a targeted oncolytic virus [J]. PLoS One,2009,4(1):e4235.
    [6]Wan G, Zhou L, Xie M, et al. Characterization of side population cells from laryngeal cancer cell lines [J]. Head Neck,2010,32(10):1302-1309.
    [7]Na YR, Seok SH, Kim DJ, et al. Isolation and characterization of spheroid cells from human malignant melanoma cell line WM-266-4[J]. Tumor Biology,2009, 30(5-6):300-309.
    [8]Li YF, Xiao B, Lai ZS, et al. Spheres isolated from Colo205 cell line possess Cancer stem-like cells under serum-free culture condition [J]. Nan Fang Yi Ke Da Xue Xue Bao,2008,28(2):236-240.
    [9]Wei XD, Zhou L, Cheng L, et al. In vivo investigation of CD 133 as a putative marker of cancer stem cells in Hep-2 cell line [J]. Head Neck,2009,31(1):94-101.
    [10]Yu SC, Ping YF, YI L, et al. Isolation and characterization of cancer stem cells from a human glioblastoma cell line U87 [J]. Cancer Letters,2008,265 (1):124-134.
    [11]Zhou XD, Wang XY, Qu FJ, et al. Detection of cancer stem cells from the C6 glioma cell line [J]. Journal of International Medical Research,2009,37(2):503-510.
    [12]Ponti D, Costa A, Zaffaroni N, et al. Isolation and in vitro propagation of tumorigenic breast cancer cells with stem/progenitor cell properties [J]. Cancer Res,2005,65(13):5506-5511.
    [13]Cheng T. Cell cycle inhibitors in normal and tumor stem cells [J]. Oncogene. 2004,23(43):7256-7266.
    [14]Sell S. Stem cell origin of cancer and differentiation therapy [J].Critical Reviews in Oncology Hematology,2004,51 (1):1-28.
    [15]Glauche I, Moore K, Thielecke L, et al. Stem cell proliferation and quiescence-two sides of the same coin [J]. PLoS Comut Biol,2009,5(7):e1000447.
    [16]Schotzer-Schrehardt U, Kruse FE. Identification and characterization of limbal stem cells [J]. Exp Eye Res,2005,81(3):247-264.
    [17]Li L, Neaves WB. Normal stem cells and cancer stem cells:the niche matters [J]. Cancer Res,2006,66(9):4553-4557.
    [18]Fuchs E, Tumbar T, Guasch G. Socializing with the neighbors:stem cells and their niche [J]. Cell,2004,116(6):769-778.
    [19]吴银艳,黄强,董军,等.干细胞niche与肿瘤干细胞产生和发展的关系[J].癌症,2008,27(1):109-112.
    [20]Al-Hajj M, Wieha MS, Benito-Hernandez A, et al. Prospective identification of tumorigenic breast cancer cells [J]. Proc Natl Acad Sci USA,2003,100(7): 3983-3988.
    [21]Thomson SP, Meyskens FL. Method for measurement of self-renewal capacity of clonogenic cells from biopsies of metastatic human-malignant Melanoma[J]. Cancer Research,1982,42(11):4606-4613.
    [22]Wieha MS, Liu SL, Dontu G. Cancer stem cells:An old idea-A paradigm shift [J]. Cancer Research,2006,66(4):1883-1890.
    [23]Cui HJ, Ma J, Ding J, et al. Bmi-1 regulates the differentiation and clonogenic self-renewal of Ⅰ-type neuroblastoma cells in a concentration-dependent manner [J]. Journal of Biologieal Chemistry 2006,281 (45):34696-34704.
    [24]Condeelis J, Segall JE. Intravital imaging of cell movement in tumours [J]. Nat Rev Cancer,2003,3(12):921-930.
    [25]Zhang B, Zhou Z, Lin H, et al. Protein phosphatase I A (PPMIA) is involved In human cytotrophoblast cell invasion and migration[J].Histoehem Cell Biol, 2009,132(2):169-179.
    [26]Al-Hajj M, Clarke MF. Self-renewal and solid tumor stem cells [J]. Oncogene. 2004,23(43):7274-7282.
    [27]Robey RW, Polgar O, Deeken J, et al. ABCG2:Determining its relevance in clinical drug resistance [J]. Cancer Metastasis Rev,2007,26(1):39-57.
    [28]Robey RW, Shukla S, Finley EM, et al. Inhibition of P-glycoprotein (ABCB1) and multidrug resistance associated protein1 (ABCC1) mediated transport by the orally administered inhibitor, CBT-1(R) [J], Biochem Pharmacol,2008,75(6): 1302-1312.
    [1]Goodell MA, Brose K, Paradis G, et al. Isolation and functional properties of murine hematopoietic stem cells that are replicating in vivo[J].J Exp Med, 1996,183(4):1797-1806.
    [2]Hirsehmann-Jax C, Foster AE, Wulf GG, et al. A distinct "side population" of cells with high drug efflux capacity in human tumor cells [J]. Proe Natl Acad Sei USA,2004,101 (39):14228-14233.
    [3]Patrawala L, Calhoun T, Schneider-Broussard R, et al. Side population is enriched in tumorigenic, stem-like cancer cells, whereas ABCG2+ and ABCG2-cancer cells are similarly tumorigenic [J]. Cancer Res,2005,65 (14):6207-6219.
    [4]Prince ME, Sivanandan R, Kaczorowski A, et al. Identification of a subpopulation of cells with cancer stem cell properties in head and neck squarous cell carcinoma [J]. Proc Natl Acad Sci USA,2007,104(3):973-978.
    [5]Haraguehi N, Utsunomiya T, Inoue H, et al. Characterization of a side population of cancer cells from human gastrointestinal system [J].Stem Cells,2006, 24(3):506-513.
    [6]Szotek PP, Pieretti-Vanmarcke R, Masiakos PT, et al. Ovarian cancer side population defines cells with stem cell-like characteristics and mullerian inhibiting substance responsiveness [J]. Proc Natl Acad Sci USA,2006,103(30):11154-11159.
    [7]Chiba T, Kita K, Zheng YW, et al. Side population purified from hepatocellular carcinoma cells harbors cancer stem cell-like properties [J]. Hepatology,2006, 44(1):240-251.
    [8]Ignatova TN, Kukekov VG, Laywell ED, et al. Human cortical glial tumors contain neural stem-like cells expressing astroglial and neuronal markers in vitro [J].Glia,2002,39(3):193-206.
    [9]Hemmati HD, Nakano I, Lazareff JA, et al. Cancerous stem cells can arise from pediatric brain tumors [J].Proc Natl Acad Sci USA,2003,100(25):15178-15183.
    [10]Singh SK, Clarke ID, Terasaki M, et al. Identification of a cancer stem cell in human brain tumors [J].Cancer Res,2003,63(18):5821-5828.
    [11]Challen GA, Little MH. A side order of stem cells:the SP phenotype[J]. Stem Cells,2006,24(1):3-12.
    [12]Wang J, Guo LP, Chen LZ, et al. Identification of cancer stem cell-like side population cells in human nasopharyngeal carcinoma cell line [J].Cancer Res, 2007,67(8):3716-3724.
    [13]Wan G, Zhou L, Xie M, et al. Characterization of side population cells from laryngeal cancer cell lines [J]. Head Neck,2010,32(10):1302-1309.
    [14]Wu C, Wei Q, Utomo V, et al. Side population cells isolated from mesenchymal neoplasms have tumor initiating potential [J]. Cancer Res,2007,67(17):8216-8222.
    [15]Wicha MS. Cancer stem cells and metastasis:lethal seeds [J]. Clin Cancer Res, 2006,12(19):5606-5607.
    [16]Hermann PC, Huber SL, Herrler T,et al. Distinct populations of cancer stem cells determine tumor growth and metastatic activity in human pancreatic cancer [J]. Cell Stem Cell,2007,1 (3):313-323.