Heterozygous loss of TSC2 alters p53 signaling and human stem cell reprogramming

• Published in: Human molecular genetics Vol. 26; no. 23; pp. 4629 - 4641
• Main Authors: Armstrong, Laura C, Westlake, Grant, Snow, John P, Cawthon, Bryan, Armour, Eric, Bowman, Aaron B, Ess, Kevin C
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-12-2017
• Subjects: Adolescent; Adult; Alleles; Cellular Reprogramming - genetics; Child; Child, Preschool; Female; Fibroblasts - metabolism; Fibroblasts - pathology; Genes, p53; Heterozygote; Humans; Induced Pluripotent Stem Cells - cytology; Induced Pluripotent Stem Cells - metabolism; Induced Pluripotent Stem Cells - physiology; Infant; Loss of Heterozygosity; Male; Mutation; RNA, Small Interfering - genetics; Signal Transduction; TOR Serine-Threonine Kinases - metabolism; Tuberous Sclerosis - genetics; Tuberous Sclerosis - metabolism; Tuberous Sclerosis - pathology; Tuberous Sclerosis Complex 1 Protein; Tuberous Sclerosis Complex 2 Protein; Tumor Suppressor Protein p53 - genetics; Tumor Suppressor Protein p53 - metabolism; Tumor Suppressor Proteins - genetics; Tumor Suppressor Proteins - metabolism
• ISSN: 0964-6906; 1460-2083
• DOI: 10.1093/hmg/ddx345

Tuberous sclerosis complex (TSC) is a pediatric disorder of dysregulated growth and differentiation caused by loss of function mutations in either the TSC1 or TSC2 genes, which regulate mTOR kinase activity. To study aberrations of early development in TSC, we generated induced pluripotent stem cells using dermal fibroblasts obtained from patients with TSC. During validation, we found that stem cells generated from TSC patients had a very high rate of integration of the reprogramming plasmid containing a shRNA against TP53. We also found that loss of one allele of TSC2 in human fibroblasts is sufficient to increase p53 levels and impair stem cell reprogramming. Increased p53 was also observed in TSC2 heterozygous and homozygous mutant human stem cells, suggesting that the interactions between TSC2 and p53 are consistent across cell types and gene dosage. These results support important contributions of TSC2 heterozygous and homozygous mutant cells to the pathogenesis of TSC and the important role of p53 during reprogramming.