Side Population Cell Level in Human Breast Cancer and Factors Related to Disease-free Survival

  • Jin, C.G. (Cancer Research Institute) ;
  • Zou, T.N. (Breast Cancer Department, Yunnan Cancer Hospital, The 3rd Affiliated Hospital of Kunming Medical University) ;
  • Li, J. (Cancer Research Institute) ;
  • Chen, X.Q. (Cancer Research Institute) ;
  • Liu, X. (Cancer Research Institute) ;
  • Wang, Y.Y. (Epidemiology and Biostatistics Department, School of Public Health, Kunming Medical University) ;
  • Wang, X. (Cancer Research Institute) ;
  • Che, Y.H. (The First Peoples Hospital of Kunming City) ;
  • Wang, X.C. (Cancer Research Institute) ;
  • Sriplung, Hutcha (Epidemiology Unit, Faculty of Medicine, Prince of Songkla University)
  • Published : 2015.03.04


Side population (SP) cells have stem cell-like properties with a capacity for self-renewal and are resistant to chemotherapy and radiotherapy. Therefore the presence of SP cells in human breast cancer probably has prognostic value. Objective: To investigate the characteristics of SP cells and identify the relationship between the SP cells levels and clinico-pathological parameters of the breast tumor and disease-free survival (DFS) in breast cancer patients. Materials and Methods: A total of 122 eligible breast cancer patients were consecutively recruited from January 1, 2006 to December 31, 2007 at Yunnan Tumor Hospital. All eligible subjects received conventional treatment and were followed up for seven years. Predictors of recurrence and/or metastasis and DFS were analyzed using Cox regression analysis. Human breast cancer cells were also obtained from fresh human breast cancer tissue and cultured by the nucleic acid dye Hoechst33342 with Verapami. Flow cytometry (FCM) was employed to isolate the cells of SP and non-SP types. Results: In this study, SP cells were identified using flow cytometric analysis with Hoechst 33342 dye efflux. Adjusted for age, tumor size, lymph nodal status, histological grade, the Cox model showed a higher risk of recurrence and/or metastasis positively associated with the SP cell level (1.75, 1.02-2.98), as well as with axillary lymph node metastasis (2.99, 1.76-5.09), pathology invasiveness type (1.7, 1.14-2.55), and tumor volume doubling time (TVDT) (1.54, 1.01-2.36). Conclusions: The SP cell level is independently associated with tumor progression and clinical outcome after controlling for other pathological factors. The axillary lymph node status, TVDT and the status of non-invasive or invasive tumor independently predict the prognosis of breast cancer.


  1. Al-Hajj M, Wicha MS, Benito-Hernandez A, et al (2003). Prospective identification of tumorigenic breast cancer cells. Proc Natl Acad Sci USA, 100, 3983-8.
  2. Alvi AJ, Clayton H, Joshi C, et al (2003). Functional and molecular characterisation of mammary side population cells. Breast Cancer Res, 5, 1-8.
  3. Campbell LL and Polyak K (2007). Breast tumor heterogeneity: cancer stem cells or clonal evolution? Cell Cycle, 6, 2332-8.
  4. Chen CY, Chiou SH, Huang CY, et al (2009). Distinct population of highly malignant cells in a head and neck squamous cell carcinoma cell line established by xenograft model. J Biomed Sci, 16, 100.
  5. Cianfrocca M and Goldstein LJ (2004). Prognostic and predictive factors in early-stage breast cancer. Oncologist, 9, 606-16.
  6. Clayton H, Titley I and Vivanco M (2004). Growth and differentiation of progenitor/stem cells derived from the human mammary gland. Exp Cell Res, 297, 444-60.
  7. Croker AK, Goodale D, Chu J, et al (2009). High aldehyde dehydrogenase and expression of cancer stem cell markers selects for breast cancer cells with enhanced malignant and metastatic ability. J Cell Mol Med, 13, 2236-52.
  8. Engelmann K, Shen H and Finn OJ (2008). MCF7 side population cells with characteristics of cancer stem/ progenitor cells express the tumor antigen MUC1. Cancer Res, 68, 2419-26.
  9. Fuchs D, Heinold A, Opelz G, et al (2009). Salinomycin induces apoptosis and overcomes apoptosis resistance in human cancer cells. Biochem Biophys Res Commun, 390, 743-9.
  10. Goodell MA, Brose K, Paradis G, et al (1996). Isolation and functional properties of murine hematopoietic stem cells that are replicating in vivo. J Exp Med, 183, 1797-806.
  11. Han JS and Crowe DL (2009). Tumor initiating cancer stem cells from human breast cancer cell lines. Int J Oncol, 34, 1449-53.
  12. Jatoi I, Hilsenbeck SG, Clark GM, et al (1999). Significance of axillary lymph node metastasis in primary breast cancer. J Clin Oncol, 17, 2334-40.
  13. Kabashima A, Higuchi H, Takaishi H, et al (2009). Side population of pancreatic cancer cells predominates in TGF-$\beta$-mediated epithelial to mesenchymal transition and invasion. Int J Cancer, 124, 2771-9.
  14. Kato K, Yoshimoto M, Kato K, et al (2007). Characterization of side-population cells in human normal endometrium. Hum Reprod, 22, 1214-23.
  15. Kusama S, Spratt JS, Donegan WL, et al (1972). The gross rates of growth of human mammary carcinoma. Cancer, 30, 594-9.<594::AID-CNCR2820300241>3.0.CO;2-2
  16. Mimeault M, Hauke R, Mehta PP, et al (2007). Recent advances in cancerstem/progenitor cell research: therapeutic implications for overcomingresistance to the most aggressive cancers. J Cell Mol Med, 11, 981-1011.
  17. Mitsutake N, Iwao A, Nagai K, et al (2007). Characterization of side population in thyroid cancer cell lines: Cancer stem-like cells are enriched partly but not exclusively. Endocrinology, 148, 1797-803.
  18. Nakanishi T, Chumsri S, Khakpour N, et al (2010). Sidepopulation cells in luminal-type breast cancer have tumour-initiating cell properties, and are regulated by HER2 expression and signalling. Br J Cancer, 102, 815-26.
  19. Nishii T, Yashiro M, Shinto O, et al (2009). Cancer stem cell-like SP cells have a high adhesion ability to the peritoneum in gastric carcinoma. Cancer Sci, 100, 1397-402.
  20. Nogami T, Shien T, Tanaka T, et al (2014). Expression of ALDH1 in axillary lymph node metastases is a prognostic factor of poor clinical outcome in breast cancer patients with 1-3 lymph node metastases. Breast Cancer, 21, 58-65.
  21. Patrawala, L., Calhoun T, R. Schneider-Broussard, et al (2005). Side population is enriched in tumorigenic, stem-like cancer cells, whereas ABCG2+ and ABCG2- cancer cells are similarly tumorigenic. Cancer Res, 65, 6207-19.
  22. Ponti D, Costa A, Zaffaroni N, et al (2005). Isolation and in vitro propagation of tumorigenic breast cancer cells with stem/progenitor cell properties. Cancer Res, 65, 5506-11.
  23. Raaijmakers MH (2007). ATP-binding-cassette transporters in hematopoieticstem cells and their utility as therapeutical targets in acute and chronicmyeloid leukemia. Leukemia, 21, 2094-02.
  24. Reya T, Morrison SJ, Clarke MF, et al (2001). Stem cells, cancer, and cancer stem cells. Nature, 414, 105-11.
  25. Rosa Mendoza ES, Moreno E and Caguioa PB (2013). Predictors of early distant metastasis in women with breast cancer. J Cancer Res Clin Oncol, 139, 645-52.
  26. Sakariassen PO, Immervoll H, Chekenya M (2007). Cancer stem cells as mediators of treatment resistance in brain tumors : status and controversies. Neoplasia, 9, 882-92.
  27. Sankaranarayanan R, Swaminathan R, Lucas E (2011). Cancer survival in Africa, Asia, the Caribbean and Central America (SurvCan). IARC scientific publications volume 162, ISBN 978-92-832-2162-3, Lyon, International Agency for Research on Cancer.
  28. Song J, Chang I, Chen Z, et al (2010). Characterization of side populations in hnscc: highly invasive, chemoresistant and abnormal wnt signaling. PLoS One, 5, 11456.
  29. Steiniger SC, Coppinger JA, Kruger JA, et al (2008). Quantitative mass spectrometry identifies drug targets in cancer stem cell containing side population. Stem Cells, 26, 3037-46.
  30. Sun Y, Liao M, Cheng G (2011). NCCN non-small cell lung cancer clinical practice guideline: Chinese Edition Version 2011. Beijing.
  31. Van den Broeck A, Vankelecom H, Van DelmW, et al (2013). Human pancreatic cancer contains a side population expressing cancer stem cell-associated and prognostic genes. PloS One, 8, 73968.
  32. Visvader JE, Lindeman GJ (2008). Cancer stem cells in solid tumours: accumulating evidence and unresolved questions. Nat Rev Cancer, 8, 755-68.
  33. Weigel MT, Dowsett M (2010). Current and emerging biomarkers in breast cancer: prognosis and prediction. Endocr Relat Cancer, 17, 245-62.
  34. Woodward WA, Chen MS, Behbod F, et al (2007). WNT/betacatenin mediates radiation resistance of mouse mammary progenitor cells. Proc Natl Acad Sci USA, 104, 618-23.
  35. Wu C and Alman BA. (2008) Side population cells in human cancers. Cancer Lett, 268, 1-9.
  36. Yang M, Zhang R, Yan M, et al (2010). Detection and characterization of side population in Ewing's sarcoma SK-ES-1 cells in vitro. Biochem Biophys Res Commun, 391, 1062-6.
  37. Yin L, Castagnino P, Assoian RK (2008). ABCG2 Expression and side population abundance regulated by a transforming growth factor {beta}-directed epithelial-mesenchymal transition. Cancer Res, 68, 800-7.
  38. Zeppernick F, Ahmadi R, Campos B, et al (2008). Stem cell markercd133 affects clinical outcome in glioma patients. Clin Cancer Res, 14, 123-9.
  39. Zhang AM, Fan Y, Yao Q, Ma H, et al (2012). Identification of a cancer stem-like population in the Lewis lung cancer cell line. Asian Pac J Cancer Prev, 13, 761-6.
  40. Zhou J, Zhang H, Gu P, et al (2008). Cancer stem/progenitor cell active compound 8-quinolinol in combination with paclitaxel achieves an improved cure of breast cancer in the mouse model. Breast Cancer Res Treat, 115, 269-77.

Cited by

  1. Do Different Stemness Markers Identify Different Pools of Cancer Stem Cells in Malignancies: A Study on ER+ and ER-Breast Cancer Cell Lines pp.1532-2807, 2018,