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.

Inhibition of growth of Asian keloid cells with human umbilical cord Wharton’s jelly stem cell-conditioned medium

“…Additionally, the qRT-PCR results showed that the anti-apoptotic gene (SURVIVIN) was downregulated and pro-apoptotic and autophagyrelated genes (BECLIN-1, BAX, ATG5, ATG7) were upregulated in AKCs exposed to hWJSC-CM, further confirming that the possible mechanisms by which hWJSC-CM induce AKCs cell death is through autophagy and apoptotic pathways. These results tally with our previous reports that hWJSC-CM increased oxidative stress, thus inducing apoptosis in lymphoma cells and keloids [32,34].…”

“…The results of the present study revealed that cell viability and proliferation rates were significantly lower in fresh uncultured Asian keloid cells (AKCs) exposed to hWJSC-CM compared to controls. Although AKCs expressed CD29, CD44, CD73, CD90, and CD105 markers [1,34], their expression was significantly reduced in the AKCs after exposure to hWJSC-CM suggesting that AKCs were losing their stemness properties but not in controls. AKCs exposed to hWJSC-CM appear to be inhibited via apoptosis as they were arrested at Sub-G1 and G2/M phases [33], which is the same focal point of cell arrest by other anti-leukemic agents [35].…”

“…p < 0.05 was considered as statistically significant promotes wound healing with reduction of hypertrophic scars [39,40]. Several groups, including our group, have shown that hWJSCs secrete high levels of hyaluronic acid, anti-inflammatory, and antifibrotic cytokines (IL10, VEGF, and HGF), and suppress the production of proinflammatory cytokines (TNF-α and IL-6) that may be responsible for reduced scarring to allow better healing [7,34,36].…”

Managing keloid scars: From radiation therapy to actual and potential drug deliveries

“…71 In addition, when human keloid cells were treated with human WJSC-conditioned medium or lysate every 72 hours for up to 9 days, they exhibited decreased proliferation, increased apoptosis, interruption of the cell cycle, and inhibition of migration. 72 In relation to amniotic stem cells, when a thoracotomy scar and its surrounding skin were injected with 2 million human amniotic stem cells mixed with amniotic membrane matrix, the intractable pain of the Caucasian male patient decreased significantly. Two additional injections completely eliminated the pain and improved the remodelling of the scar.…”

Inhibiting function of human fetal dermal mesenchymal stem cells on bioactivities of keloid fibroblasts

“…Recent studies show that MSCs can regulate the wound-healing process and prevent scar formation in keloid formation, suggesting their promising therapeutic role in keloid. The paracrine role of MSCs is also attracting particular attention for their therapeutic effect on wound healing, tissue repair, and scar remodeling [18–20]. Reports have demonstrated that the use of adipose-derived MSCs could facilitate cutaneous wound healing and form a thinner scar, and the underlying mechanisms involved are the downregulated expression of transforming growth factor (TGF)-β1, decreased accumulation of collagen, and increased expression of decorin [21].…”