Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, Kent Ridge, 119228, Singapore.
Department of Surgery, Kent Ridge, 119228, Singapore.
Stem Cell Res Ther. 2020 Feb 21;11(1):78. doi: 10.1186/s13287-020-01609-7.
Keloid 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).
Human 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.
qRT-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.
hWJSC-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.
瘢痕疙瘩在白种人、黑种人和亚洲人群中都会发生，这给患者带来了严重的心理社会负担。由于其发病机制尚未得到充分理解，因此目前尚无针对这种疾病的永久性治疗方法。此外，不同种族之间的瘢痕疙瘩行为也尚不清楚。人们假设瘢痕疙瘩之所以会生长失控，是因为它们表现出良性肿瘤的特征。本研究评估了人脐带沃顿胶干细胞条件培养基（hWJSC-CM）对新鲜亚洲瘢痕疙瘩细胞（AKC）的杀肿瘤特性。
基于我们之前的方法，分离出人脐带沃顿胶干细胞（hWJSCs）和 AKC。hWJSCs 和人皮肤成纤维细胞（HSF）（对照）用于收集 hWJSC-CM 和 HSF 条件培养基（HSF-CM）。体外和体内通过人瘢痕疙瘩异种移植 SCID 小鼠模型，用 hWJSC-CM 和 HSF-CM 处理 AKC。使用各种检测方法在体外测试 hWJSC-CM 对 AKC 的抑制作用，并在体内测试其在异种移植小鼠模型中是否可以减轻/消除 AKC 肿瘤。
qRT-PCR 分析显示，AKC 中 FN1、MMP1 和 VCAN 基因显著上调，而 ANXA1、ASPN、IGFBP7、LGALS1 和 PTN 基因下调。与对照组相比，体外暴露于 hWJSC-CM 的 AKC 细胞活力和增殖显著降低， Annexin V-FITC+细胞数量增加，细胞周期在 Sub-G1 和 G2/M 期中断，CD 标志物表达改变，抗凋亡相关基因下调，促凋亡和自噬相关基因上调。当 AKC 与 hWJSC-CM 一起给予免疫缺陷小鼠时，与未治疗的对照组相比，10 只小鼠中有 7 只（n=10）未形成瘢痕疙瘩肿瘤。当 hWJSC-CM 直接注射到小鼠体内形成的瘢痕疙瘩肿瘤中时，30 天后瘢痕疙瘩肿瘤体积和重量明显减少。
hWJSC-CM 抑制 AKC 的体外和异种移植小鼠的生长，可能是人类瘢痕疙瘩的一种潜在新疗法。需要鉴定、表征并在更大的临床前和临床研究中单独测试 hWJSC-CM 中诱导抗瘢痕疙瘩作用的特定分子。
