Inhibition of growth of Asian keloid cells with human umbilical cord Wharton\u2019s jelly stem cell-conditioned medium

Subramanian Arjunan,Mahesh Choolani,Shu Uin Gan,Arijit Biswas,Jane Lim,Chui Yee Fong,Vaishnevi Raj,Ariff Bongso

doi:10.1186/s13287-020-01609-7

Subramanian Arjunan, Mahesh Choolani + Show 6 more

Open Access

https://doi.org/10.1186/s13287-020-01609-7

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Abstract

BackgroundKeloid formation occurs in Caucasian, African, and Asian populations and is a severe psychosocial burden on patients. There is no permanent treatment for this problem as its pathogenesis is not properly understood. Furthermore, differences in keloid behavior between ethnic groups are not known. It has been hypothesized that keloids behave like benign tumors because of their uncontrolled growth. The present study evaluated the tumoricidal properties of human Wharton’s jelly stem cell-conditioned medium (hWJSC-CM) on fresh Asian keloid cells (AKCs).MethodsHuman Wharton’s jelly stem cells (hWJSCs) and AKCs were isolated based on our previous methods. hWJSCs and human skin fibroblasts (HSF) (controls) were used to collect hWJSC-CM and HSF-conditioned medium (HSF-CM). AKCs were treated with hWJSC-CM and HSF-CM in vitro and in vivo in a human keloid xenograft SCID mouse model. The inhibitory effect of hWJSC-CM on AKCs was tested in vitro using various assays and in vivo for attenuation/abrogation of AKC tumors created in a xenograft mouse model.ResultsqRT-PCR analysis showed that the genes FN1, MMP1, and VCAN were significantly upregulated in AKCs and ANXA1, ASPN, IGFBP7, LGALS1, and PTN downregulated. AKCs exposed to hWJSC-CM in vitro showed significant decreases in cell viability and proliferation, increases in Annexin V-FITC+ cell numbers, interruptions of the cell cycle at Sub-G1 and G2/M phases, altered CD marker expression, downregulated anti-apoptotic-related genes, and upregulated pro-apoptotic and autophagy-related genes compared to controls. When AKCs were administered together with hWJSC-CM into immunodeficient mice there were no keloid tumors formed in 7 mice (n = 10) compared to the untreated control mice. When hWJSC-CM was injected directly into keloid tumors created in mice there were significant reductions in keloid tumor volumes and weights in 30 days.ConclusionshWJSC-CM inhibited the growth of AKCs in vitro and in xenograft mice, and it may be a potential novel treatment for keloids in the human. The specific molecule(s) in hWJSC-CM that induce the anti-keloid effect need to be identified, characterized, and tested separately in larger preclinical and clinical studies.

Highlights

Keloid formation occurs in Caucasian, African, and Asian populations and is a severe psychosocial burden on patients
Cell cycle analysis Cell cycle analysis using flow cytometry of propidium iodide (PI) staining was done to compare the Asian keloid cells (AKC) exposed to Human Wharton’s jelly stem cells (hWJSCs)-CM, human skin fibroblasts (HSF)-CM, and control
Results Quantitative real-time polymerase chain reaction (qRT-PCR) and confocal microscopic analysis of Asian keloid cells Asian keloid cells (AKCs) were significantly upregulated for the keloid and matrix assembly-related genes such as A2M, FN1, MMP1, VCAN, C5orf13, HIF1a, SERPINH1, ACAN3, TNFAIP6, INHBA, DCN, FMOD, Transforming growth factor-beta (TGF)-β1, and TGF-β3; and downregulated for ANXA1, ASPN, IGFBP7, LGALS1, and PTN compared to human skin fibroblasts (HSFs)

Summary

Introduction

Keloid formation occurs in Caucasian, African, and Asian populations and is a severe psychosocial burden on patients. Keloids are characterized by a painful pruritic raised scar that grows beyond the boundary of the original margin of wounds. It commonly involves the shoulders, ear lobes, upper arm, and anterior back [1]. Hypertrophic scars are similar to keloids but possess some clinical, histological, and epidemiological differences between them that suggest that they may be two distinct entities. Hypertrophic scars unlike keloids do not extend beyond the initial site of injury, have low recurrence rates after excision, and histologically possess well organized, wavy type III collagen bundles oriented parallel to the epidermal surface with abundant nodules containing myofibroblasts. It has been suggested that, given these differences between keloids and hypertrophic scars, there is a need for proper characterization of keloids between ethnicities with the recommendation of a specific set of signature markers for their reliable identification

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