CDKN2B upregulation prevents teratoma formation in multipotent fibromodulin-reprogrammed cells
Zhong Zheng, … , Kang Ting, Chia Soo
Zhong Zheng, … , Kang Ting, Chia Soo
Published July 15, 2019
Citation Information: J Clin Invest. 2019;129(8):3236-3251. https://doi.org/10.1172/JCI125015.
View: Text | PDF
Research Article Cell biology

CDKN2B upregulation prevents teratoma formation in multipotent fibromodulin-reprogrammed cells

Abstract

Tumorigenicity is a well-documented risk to overcome for pluripotent or multipotent cell applications in regenerative medicine. To address the emerging demand for safe cell sources in tissue regeneration, we established a novel, protein-based reprogramming method that does not require genome integration or oncogene activation to yield multipotent fibromodulin (FMOD)-reprogrammed (FReP) cells from dermal fibroblasts. When compared with induced pluripotent stem cells (iPSCs), FReP cells exhibited a superior capability for bone and skeletal muscle regeneration with markedly less tumorigenic risk. Moreover, we showed that the decreased tumorigenicity of FReP cells was directly related to an upregulation of cyclin-dependent kinase inhibitor 2B (CDKN2B) expression during the FMOD reprogramming process. Indeed, sustained suppression of CDKN2B resulted in tumorigenic, pluripotent FReP cells that formed teratomas in vivo that were indistinguishable from iPSC-derived teratomas. These results highlight the pivotal role of CDKN2B in cell fate determination and tumorigenic regulation and reveal an alternative pluripotent/multipotent cell reprogramming strategy that solely uses FMOD protein.

Authors

Zhong Zheng, Chenshuang Li, Pin Ha, Grace X. Chang, Pu Yang, Xinli Zhang, Jong Kil Kim, Wenlu Jiang, Xiaoxiao Pang, Emily A. Berthiaume, Zane Mills, Christos S. Haveles, Eric Chen, Kang Ting, Chia Soo

×

Figure 2

FReP cell implantation in SCID mouse TA muscle leads to the generation of skeletal muscle.

Options: View larger image (or click on image) Download as PowerPoint
FReP cell implantation in SCID mouse TA muscle leads to the generation o...
(A) TA muscles of SCID mice were weighed, and the left (implantation side) and right (control with no implantation) muscles were compared at 6 weeks after implantation. Two animals implanted with retrovirus-mediated BJ-iPSCs formed tumors (highlighted by dashed lines). Data are presented as mean values. **P < 0.005 (analyzed by 1-tailed Mann-Whitney and Kruskal-Wallis ANOVA tests); n = 8 or 6 (BJ-iPSC group, excluding the 2 tumor-formation animals whose histological evaluation are shown in Supplemental Figure 2). Black asterisks indicate significance in comparison with the PBS vehicle control group; blue asterisks indicate significance in comparison with the FReP cell–implanted group. (B) Confocal microscopy images showing the coronal section view of SCID mouse TA muscles. Staining of ACTA1 was reduced to better visualize the staining of human MHC class I. The spatial colocalization of skeletal muscle marker ACTA1 with human MHC class I and human mitochondria shows the myogenic differentiation and engraftment of BJ-iPSCs, FReP-basal cells, and FReP cells in vivo. Scale bars: 25 μm. Confocal microscopy images showing the transverse section view of SCID mouse TA muscles are presented in Supplemental Figure 1.