title: Human non-small cell lung cancer expresses putative cancer stem cell markers and exhibits the transcriptomic profile of multipotent cells.
abstract: BACKGROUND
  Despite significant advances in staging and therapies, lung cancer remains a major cause of cancer-related lethality due to its high incidence and recurrence. Clearly, a novel approach is required to develop new therapies to treat this devastating disease. Recent evidence indicates that tumours contain a small population of cells known as cancer stem cells (CSCs) that are responsible for tumour maintenance, spreading and resistant to chemotherapy. The genetic composition of CSCs so far is not fully understood, but manipulation of the specific genes that maintain their integrity would be beneficial for developing strategies to combat cancer. Therefore, the goal of this study isto identify the transcriptomic composition and biological functions of CSCs from non-small cell lung cancer (NSCLC).
  
  
  METHODS
  We isolated putative lung CSCs from lung adenocarcinoma cells (A549 and H2170) and normal stem cells from normal bronchial epithelial cells (PHBEC) on the basis of positive expression of stem cell surface markers (CD166, CD44, and EpCAM) using fluorescence-activated cell sorting. The isolated cells were then characterised for their self-renewal characteristics, differentiation capabilities, expression of stem cell transcription factor and in vivo tumouregenicity. The transcriptomic profiles of putative lung CSCs then were obtained using microarray analysis. Significantly regulated genes (p < 0.05, fold change (FC) > 2.0) in putative CSCs were identified and further analysed for their biological functions using the Database for Annotation, Visualization, and Integrated Discovery (DAVID).
  
  
  RESULTS
  The putative lung CSCs phenotypes of CD166(+)/CD44(+) and CD166(+)/EpCAM(+) showed multipotent characteristics of stem cells, including the ability to differentiate into adipogenic and osteogenic cells, self-renewal, and expression of stem cell transcription factors such as Sox2 and Oct3/4. Moreover, the cells also shows the in vivo tumouregenicity characteristic when transplanted into nude mice. Microarray and bioinformatics data analyses revealed that the putative lung CSCs have molecular signatures of both normal and cancer stem cells and that the most prominent biological functions are associated with angiogenesis, migration, pro-apoptosis and anti-apoptosis, osteoblast differentiation, mesenchymal cell differentiation, and mesenchyme development. Additionally, self-renewal pathways such as the Wnt and hedgehog signalling pathways, cancer pathways, and extracellular matrix (ECM)-receptor interaction pathways are significantly associated with the putative lung CSCs.
  
  
  CONCLUSIONS
  This study revealed that isolated lung CSCs exhibit the characteristics of multipotent stem cells and that their genetic composition might be valuable for future gene and stem cells therapy for lung cancer.
authors.affiliation: Regenerative Medicine Cluster, Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Pulau Pinang, Malaysia. norashikin.zakaria@yahoo.com.
authors.forename: Norashikin
authors.initials: N
authors.lastname: Zakaria
authors.affiliation: Regenerative Medicine Cluster, Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Pulau Pinang, Malaysia. narazah@amdi.usm.edu.my.
authors.forename: Narazah Mohd
authors.initials: NM
authors.lastname: Yusoff
authors.affiliation: Stem Cell Laboratory, Haematology Unit, Cancer Research Centre, Institute for Medical Research (IMR), Kuala Lumpur, Malaysia. zubaidah@imr.gov.my.
authors.forename: Zubaidah
authors.initials: Z
authors.lastname: Zakaria
authors.affiliation: Stem Cell Laboratory, Haematology Unit, Cancer Research Centre, Institute for Medical Research (IMR), Kuala Lumpur, Malaysia. lisa@imr.gov.my.
authors.forename: Moon Nian
authors.initials: MN
authors.lastname: Lim
authors.affiliation: Stem Cell Laboratory, Haematology Unit, Cancer Research Centre, Institute for Medical Research (IMR), Kuala Lumpur, Malaysia. puteri@imr.gov.my.
authors.forename: Puteri J Noor
authors.initials: PJ
authors.lastname: Baharuddin
authors.affiliation: Stem Cell Laboratory, Haematology Unit, Cancer Research Centre, Institute for Medical Research (IMR), Kuala Lumpur, Malaysia. kamal@imr.gov.my.
authors.forename: Kamal Shaik
authors.initials: KS
authors.lastname: Fakiruddin
authors.affiliation: Regenerative Medicine Cluster, Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia, Bertam, 13200, Kepala Batas, Pulau Pinang, Malaysia. badrul@amdi.usm.edu.my.
authors.forename: Badrul
authors.initials: B
authors.lastname: Yahaya
mesh_terms: D000818:Animals; D015415:Biomarkers; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D002454:Cell Differentiation / Q000235:genetics; D045744:Cell Line, Tumor; D000066673:Cell Self Renewal / Q000235:genetics; D002471:Cell Transformation, Neoplastic / Q000235:genetics / Q000378:metabolism; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D015972:Gene Expression Regulation, Neoplastic; D063990:Gene Ontology; D064593:Heterografts; D006801:Humans; D016130:Immunophenotyping; D008175:Lung Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D051379:Mice; D014411:Neoplastic Stem Cells / Q000378:metabolism* / Q000473:pathology; D015203:Reproducibility of Results; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D059467:Transcriptome
chemical_list: D015415:Biomarkers; D014157:Transcription Factors