Essentiality of CTNNB1 in Malignant Transformation of Human Embryonic Stem Cells under Long-Term Suboptimal Conditions.

Human embryonic stem cells (hESCs) gradually accumulate abnormal karyotypes during long-term suboptimal culture, which hinder their application in regenerative medicine. Previous studies demonstrated that the activation of might be implicated in this process. Hence, the hESC line with stably silenced was established to further explore the role of in the malignant transformation of hESCs. It was shown to play a vital role in the maintenance of the physiological properties of stem cells, such as proliferation, migration, differentiation, and telomere regulation. Furthermore, the malignant transformation of hESCs was induced by continuous exposure to 0.001 g/ml mitomycin C (MMC). The results showed that and its target genes, including proto-oncogenes and , were aberrantly upregulated in hESCs after MMC treatment. Moreover, the high expression of accelerated cell transition from G0/G1 phase to the S phase and stimulated the growth of cells containing breakage-fusion-bridge (BFB) cycles. Conversely, silencing inhibited these effects and triggered a survival crisis. The current data indicated that is intimately associated with the physiological properties of stem cells; however, the aberrant expression of is involved in the malignant transformation of hESCs, which might advance the process by facilitating telomere-related unstable cell proliferation. Thus, the aberrant CTNNB1 level might serve as a potential biomarker for detecting the malignant transformation of hESCs.