Limits...
Identification of CD24 as a cancer stem cell marker in human nasopharyngeal carcinoma.

Yang CH, Wang HL, Lin YS, Kumar KP, Lin HC, Chang CJ, Lu CC, Huang TT, Martel J, Ojcius DM, Chang YS, Young JD, Lai HC - PLoS ONE (2014)

Bottom Line: In this study, we show that CD24+ cells isolated from human NPC cell lines express stem cell genes (Sox2, Oct4, Nanog, Bmi-1, and Rex-1), and show activation of the Wnt/β-catenin signaling pathway.CD24+ cells further show increased invasion ability in vitro, which correlates with enhanced expression of matrix metalloproteinase 2 and 9.In summary, our results suggest that CD24 represents a novel CSC biomarker in NPC.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung, Taiwan, Republic of China.

ABSTRACT
Cancer stem cells (CSCs) represent a unique sub-population of tumor cells with the ability to initiate tumor growth and sustain self-renewal. Although CSC biomarkers have been described for various tumors, only a few markers have been identified for nasopharyngeal carcinoma (NPC). In this study, we show that CD24+ cells isolated from human NPC cell lines express stem cell genes (Sox2, Oct4, Nanog, Bmi-1, and Rex-1), and show activation of the Wnt/β-catenin signaling pathway. CD24+ cells possess typical CSC characteristics that include enhanced cell proliferation, increased colony and sphere formation, maintenance of cell differentiation potential in prolonged culture, and enhanced resistance to chemotherapeutic drugs. Notably, CD24+ cells produce tumors following inoculation of as few as 500 cells in immunodeficient NOD/SCID mice. CD24+ cells further show increased invasion ability in vitro, which correlates with enhanced expression of matrix metalloproteinase 2 and 9. In summary, our results suggest that CD24 represents a novel CSC biomarker in NPC.

Show MeSH

Related in: MedlinePlus

CD24+ cells show enhanced chemoresistance.(A) Sorted CD24+ and CD24− cells from the TW02 and TW04 NPC cell lines were treated or not with 50 µM verapamil for 30 min prior to processing for the Hoechst 33342 dye exclusion assay as described in Materials and Methods. (B) Parental, CD24+, and CD24− cells from the TW02 or TW04 cell lines were treated with various concentrations of cisplatin and docetaxel for 24 h, and cell viability was determined using the MTT assay. CD24+ cells showed higher viability than parental and CD24− cells after treatment with either cisplatin or docetaxel. The results shown represented the average of three independent experiments. *: p<0.05, **: p<0.01, ***: p<0.001. IC50 values of cisplatin or docetaxel treatment against parental, CD24+, and CD24− cells were shown for (C) TW02 and (D) TW04 cells lines.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4067285&req=5

pone-0099412-g005: CD24+ cells show enhanced chemoresistance.(A) Sorted CD24+ and CD24− cells from the TW02 and TW04 NPC cell lines were treated or not with 50 µM verapamil for 30 min prior to processing for the Hoechst 33342 dye exclusion assay as described in Materials and Methods. (B) Parental, CD24+, and CD24− cells from the TW02 or TW04 cell lines were treated with various concentrations of cisplatin and docetaxel for 24 h, and cell viability was determined using the MTT assay. CD24+ cells showed higher viability than parental and CD24− cells after treatment with either cisplatin or docetaxel. The results shown represented the average of three independent experiments. *: p<0.05, **: p<0.01, ***: p<0.001. IC50 values of cisplatin or docetaxel treatment against parental, CD24+, and CD24− cells were shown for (C) TW02 and (D) TW04 cells lines.

Mentions: Higher resistance to chemotherapeutic drugs represents a critical characteristic of CSCs [9]. Previous studies have reported that CSCs can exclude the DNA-binding dye, Hoechst 33342, due to enhanced expression of the ABC transporter, ABCG2 [41], [42]. To determine whether CD24+ cells exclude Hoechst 33342 better than parental or CD24− cells, we performed the dye exclusion assay after treating TW02 cells with the ABC transporter inhibitor, verapamil [43]. As shown in Figure 5A, a larger population of Hoechst 33342-negative cells was observed for CD24+ cells (12.9%) compared with CD24− cells (7.99%). Notably, verapamil treatment reversed the dye exclusion phenotype observed in CD24+ cells, while this treatment had no significant effect on CD24− cells (Figure 5A). Similar results were obtained for the TW04 cell line (verapamil produced no significant effect in this case since almost no TW04 CD24− cells were Hoechst 33342-negative). These observations suggest that CD24+ cells possess an enhanced ability to exclude dye.


Identification of CD24 as a cancer stem cell marker in human nasopharyngeal carcinoma.

Yang CH, Wang HL, Lin YS, Kumar KP, Lin HC, Chang CJ, Lu CC, Huang TT, Martel J, Ojcius DM, Chang YS, Young JD, Lai HC - PLoS ONE (2014)

CD24+ cells show enhanced chemoresistance.(A) Sorted CD24+ and CD24− cells from the TW02 and TW04 NPC cell lines were treated or not with 50 µM verapamil for 30 min prior to processing for the Hoechst 33342 dye exclusion assay as described in Materials and Methods. (B) Parental, CD24+, and CD24− cells from the TW02 or TW04 cell lines were treated with various concentrations of cisplatin and docetaxel for 24 h, and cell viability was determined using the MTT assay. CD24+ cells showed higher viability than parental and CD24− cells after treatment with either cisplatin or docetaxel. The results shown represented the average of three independent experiments. *: p<0.05, **: p<0.01, ***: p<0.001. IC50 values of cisplatin or docetaxel treatment against parental, CD24+, and CD24− cells were shown for (C) TW02 and (D) TW04 cells lines.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4067285&req=5

pone-0099412-g005: CD24+ cells show enhanced chemoresistance.(A) Sorted CD24+ and CD24− cells from the TW02 and TW04 NPC cell lines were treated or not with 50 µM verapamil for 30 min prior to processing for the Hoechst 33342 dye exclusion assay as described in Materials and Methods. (B) Parental, CD24+, and CD24− cells from the TW02 or TW04 cell lines were treated with various concentrations of cisplatin and docetaxel for 24 h, and cell viability was determined using the MTT assay. CD24+ cells showed higher viability than parental and CD24− cells after treatment with either cisplatin or docetaxel. The results shown represented the average of three independent experiments. *: p<0.05, **: p<0.01, ***: p<0.001. IC50 values of cisplatin or docetaxel treatment against parental, CD24+, and CD24− cells were shown for (C) TW02 and (D) TW04 cells lines.
Mentions: Higher resistance to chemotherapeutic drugs represents a critical characteristic of CSCs [9]. Previous studies have reported that CSCs can exclude the DNA-binding dye, Hoechst 33342, due to enhanced expression of the ABC transporter, ABCG2 [41], [42]. To determine whether CD24+ cells exclude Hoechst 33342 better than parental or CD24− cells, we performed the dye exclusion assay after treating TW02 cells with the ABC transporter inhibitor, verapamil [43]. As shown in Figure 5A, a larger population of Hoechst 33342-negative cells was observed for CD24+ cells (12.9%) compared with CD24− cells (7.99%). Notably, verapamil treatment reversed the dye exclusion phenotype observed in CD24+ cells, while this treatment had no significant effect on CD24− cells (Figure 5A). Similar results were obtained for the TW04 cell line (verapamil produced no significant effect in this case since almost no TW04 CD24− cells were Hoechst 33342-negative). These observations suggest that CD24+ cells possess an enhanced ability to exclude dye.

Bottom Line: In this study, we show that CD24+ cells isolated from human NPC cell lines express stem cell genes (Sox2, Oct4, Nanog, Bmi-1, and Rex-1), and show activation of the Wnt/β-catenin signaling pathway.CD24+ cells further show increased invasion ability in vitro, which correlates with enhanced expression of matrix metalloproteinase 2 and 9.In summary, our results suggest that CD24 represents a novel CSC biomarker in NPC.

View Article: PubMed Central - PubMed

Affiliation: Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan, Republic of China; Division of Applied Toxicology, Taiwan Agricultural Chemicals and Toxic Substances Research Institute, Council of Agriculture, Executive Yuan, Taichung, Taiwan, Republic of China.

ABSTRACT
Cancer stem cells (CSCs) represent a unique sub-population of tumor cells with the ability to initiate tumor growth and sustain self-renewal. Although CSC biomarkers have been described for various tumors, only a few markers have been identified for nasopharyngeal carcinoma (NPC). In this study, we show that CD24+ cells isolated from human NPC cell lines express stem cell genes (Sox2, Oct4, Nanog, Bmi-1, and Rex-1), and show activation of the Wnt/β-catenin signaling pathway. CD24+ cells possess typical CSC characteristics that include enhanced cell proliferation, increased colony and sphere formation, maintenance of cell differentiation potential in prolonged culture, and enhanced resistance to chemotherapeutic drugs. Notably, CD24+ cells produce tumors following inoculation of as few as 500 cells in immunodeficient NOD/SCID mice. CD24+ cells further show increased invasion ability in vitro, which correlates with enhanced expression of matrix metalloproteinase 2 and 9. In summary, our results suggest that CD24 represents a novel CSC biomarker in NPC.

Show MeSH
Related in: MedlinePlus