title: Human keloid cell characterization and inhibition of growth with human Wharton's jelly stem cell extracts.
abstract: Keloids are firm rubbery growths that grow beyond the boundaries of human wounds and their treatment has met with limited success. Their properties and growth behavior have not been properly characterized and it has been suggested that a benign neoplastic stem cell-like phenotype in an altered cytokine microenvironment drives their uncontrolled cell proliferation. Modification of the stem cell niche may be an attractive approach to its prevention. We studied the growth behavior, stemness, and tumorigenic characteristics of keloid cells in prolonged culture. Since human Wharton's jelly stem cells (hWJSCs) secrete high levels of cytokines and have anti-tumorigenic properties we explored its role on the inhibition of keloid growth in vitro. Keloid cells grew readily in both adherent and sphere culture and expressed high levels of mesenchymal CD and tumor-associated fibroblast (TAF) markers up to passage 10. When they were exposed to repeat doses of hWJSC conditioned medium (hWJSC-CM) and lysate (hWJSC-CL) every 72 h up to 9 days their growth was inhibited with a reduction in CD and TAF marker expression. On Days 3, 6, and 9 treated keloid cells showed linear decreases in cell proliferation (BrdU), increases in Annexin V-FITC and TUNEL-positive cells, interruptions of the cell cycle and inhibition of migration in scratch-wound assays. Immunocytochemistry and qRT-PCR confirmed a significant downregulation of TAF and anti-apoptotic-related gene (SURVIVIN) expression and upregulation of autophagy-related (BAX, ATG5, ATG7, BECLIN-1) gene expression. The results suggest that hWJSCs or molecules secreted by them may be of therapeutic value in the treatment of keloids.
authors.affiliation: Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Kent Ridge, Singapore, 119228, Singapore.
authors.forename: Chui-Yee
authors.initials: CY
authors.lastname: Fong
authors.forename: Arijit
authors.initials: A
authors.lastname: Biswas
authors.forename: Arjunan
authors.initials: A
authors.lastname: Subramanian
authors.forename: Akshaya
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Mahesh
authors.initials: M
authors.lastname: Choolani
authors.forename: Ariff
authors.initials: A
authors.lastname: Bongso
mesh_terms: D017209:Apoptosis / Q000235:genetics; D051017:Apoptosis Regulatory Proteins / Q000235:genetics / Q000378:metabolism; D001343:Autophagy / Q000235:genetics; D000071186:Beclin-1; D002453:Cell Cycle / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002457:Cell Extracts / Q000737:chemistry / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D007627:Keloid / Q000378:metabolism*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D059630:Mesenchymal Stem Cells / Q000737:chemistry / Q000473:pathology*; D008869:Microtubule-Associated Proteins / Q000235:genetics
chemical_list: D051017:Apoptosis Regulatory Proteins; C491997:BECN1 protein, human; D000071186:Beclin-1; D002457:Cell Extracts; D008565:Membrane Proteins; D008869:Microtubule-Associated Proteins
keywords: CONDITIONED MEDIUM; GROWTH INHIBITION; HUMAN WHARTON'S JELLY STEM CELLS; KELOIDS; LYSATE