Cellular senescence is a hallmark of normal aging and aging-related syndromes, including the premature aging disorder Hutchinson-Gilford Progeria Syndrome (HGPS), a rare genetic disorder caused by a single mutation in the LMNA gene that results in the constitutive expression of a truncated splicing mutant of lamin A known as progerin. Progerin accumulation leads to increased cellular stresses including unrepaired DNA damage, activation of the p53 signaling pathway and accelerated senescence. We previously established that the p53 isoforms ∆133p53 and p53β regulate senescence in normal human cells. However, their role in premature aging is unknown. Here we report that p53 isoforms are expressed in primary fibroblasts derived from HGPS patients, are associated with their accelerated senescence and that their manipulation can restore the replication capacity of HGPS fibroblasts. We found that in near-senescent HGPS fibroblasts, which exhibit low levels of ∆133p53 and high levels of p53β, restoration of Δ133p53 expression was sufficient to extend replicative lifespan and delay senescence, despite progerin levels and abnormal nuclear morphology remaining unchanged. Conversely, Δ133p53 depletion or p53β overexpression accelerated the onset of senescence in otherwise proliferative HGPS fibroblasts. Our data indicate that Δ133p53 exerts its role by modulating full-length p53 (FLp53) signaling to extend the replicative lifespan and promotes the repair of spontaneous progerin-induced DNA double-strand breaks (DSBs). We showed that Δ133p53 dominant-negative inhibition of FLp53 occurs directly at the p21/CDKN1A and miR-34a promoters, two p53 senescence-associated genes. In addition, Δ133p53 expression increased the expression of DNA repair RAD51, likely through upregulation of E2F1, a transcription factor that activates RAD51, to promote repair of DSBs. In summary, our data indicate that Δ133p53 modulates p53 signaling to repress progerin-induced early onset of senescence in HGPS cells. Therefore, restoration of ∆133p53 expression may be a novel therapeutic strategy to treat aging-associated phenotypes of HGPS in vivo.
- MeSH
- časové faktory MeSH
- fibroblasty patologie fyziologie MeSH
- kultivované buňky MeSH
- lidé MeSH
- nádorový supresorový protein p53 genetika fyziologie MeSH
- poškození DNA genetika MeSH
- předčasné stárnutí genetika patologie MeSH
- progerie genetika patologie MeSH
- protein - isoformy fyziologie MeSH
- stárnutí buněk genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Triple-negative breast cancers (TNBC) comprise a heterogeneous subgroup of tumors with a generally poor prognosis. Subclassification of TNBC based on genomic analyses shows that basal-like TNBCs, specifically the basal A or BL2 subtype, are characterized by the expression of ΔNp63, a transcription factor that has been attributed a variety of roles in the regulation of proliferation, differentiation, and cell survival. To investigate the role(s) of p63 in basal-like breast cancers, we used HCC1806 cells that are classified as basal A/BL2. We show that these cells endogenously express p63, mainly as the ΔNp63α isoform. TP63 gene knockout by CRISPR resulted in viable cells that proliferate more slowly and adhere less tightly, with an increased rate of migration. Analysis of adhesion-related gene expression revealed a complex set of alterations in p63-depleted cells, with both increased and decreased adhesion molecules and adhesion substrates compared to parental cells expressing p63. Examination of the phenotype of these cells indicated that endogenous p63 is required to suppress the expression of luminal markers and maintain the basal epithelial phenotype, with increased levels of both CK8 and CK18 and a reduction in N-cadherin levels in cells lacking p63. On the other hand, the level of CK5 was not decreased and ER was not increased, indicating that p63 loss is insufficient to induce full luminal-type differentiation. Taken together, these data demonstrate that p63 exerts multiple pro-oncogenic effects on cell differentiation, proliferation and adhesion in basal-like breast cancers.
- MeSH
- buněčná adheze MeSH
- buněčná diferenciace MeSH
- CD antigeny biosyntéza genetika MeSH
- CRISPR-Cas systémy MeSH
- epitelové buňky metabolismus patologie MeSH
- fenotyp MeSH
- genový knockout MeSH
- kadheriny biosyntéza genetika MeSH
- karcinom patologie MeSH
- keratiny biosyntéza genetika MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- nádorové proteiny fyziologie MeSH
- nádorové supresorové proteiny nedostatek fyziologie MeSH
- proliferace buněk MeSH
- protein - isoformy fyziologie MeSH
- regulace genové exprese u nádorů MeSH
- transkripční faktory nedostatek fyziologie MeSH
- triple-negativní karcinom prsu patologie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
The transcription factor p63 has important functions in tumorigenesis, epidermal differentiation and stem cell self-renewal. The TP63 gene encodes multiple protein isoforms that have different or even antagonistic roles in these processes. The balance of p63 isoforms, together with the presence or absence of the other p53 family members, p73 and p53, has a striking biological impact. There is increasing evidence that interactions between p53-family members, whether cooperative or antagonistic, are involved in various cell processes. This review summarizes the current understanding of the role of p63 in tumorigenesis, metastasis, cell migration and senescence. In particular, recent data indicate important roles in adult stem cell and cancer stem cell regulation and in the response of cancer cells to therapy.
- MeSH
- kmenové buňky metabolismus MeSH
- lidé MeSH
- myši MeSH
- nádorové kmenové buňky metabolismus MeSH
- nádorové supresorové proteiny genetika metabolismus fyziologie MeSH
- nádory metabolismus MeSH
- protein - isoformy genetika metabolismus fyziologie MeSH
- transkripční faktory genetika metabolismus fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Death receptor 6 (DR6/TNFRSF21) is a death domain-containing receptor of the TNFR superfamily with an apparent regulatory function in hematopoietic and neuronal cells. In this study we document that DR6 is an extensively posttranslationally modified transmembrane protein and that N- and O-glycosylations of amino acids in its extracellular part are mainly responsible for its approximately 40 kDa mobility shift in SDS polyacrylamide gels. Site-directed mutagenesis confirmed that all six extracellular asparagines are N-glycosylated and that the Ser/Thr/Pro cluster in the "stalk" domain juxtaposed to the cysteine-rich domains (CRDs) is a major site for the likely mucine-type of O-glycosylation. Deletion of the entire linker region between CRDs and the transmembrane domain, spanning over 130 amino acids, severely compromises the plasma membrane localization of DR6 and leads to its intracellular retention. Biosynthetic labeling with radiolabeled palmitate and side-directed mutagenesis also revealed that the membrane-proximal Cys368 in the intracellular part of DR6 is, similarly as cysteines in Fas/CD95 or DR4 ICPs, S-palmitoylated. However, palmitoylation of Cys368 is apparently not required for DR6 targeting into Brij-98 insoluble lipid rafts. In contrast, we show that N-glycosylation of the extracellular part might participate in directing DR6 into these membrane microdomains.
- MeSH
- buněčné linie MeSH
- glykosylace MeSH
- HeLa buňky MeSH
- HL-60 buňky MeSH
- Jurkat buňky MeSH
- lidé MeSH
- lipoylace MeSH
- membránové mikrodomény metabolismus MeSH
- molekulová hmotnost MeSH
- mutageneze cílená MeSH
- nádorové buněčné linie MeSH
- posttranslační úpravy proteinů MeSH
- protein - isoformy fyziologie genetika chemie MeSH
- receptory TNF genetika chemie metabolismus MeSH
- rekombinantní proteiny genetika chemie metabolismus MeSH
- sekvenční delece MeSH
- terciární struktura proteinů MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- antigeny CD44 analýza fyziologie MeSH
- finanční podpora výzkumu jako téma MeSH
- karcinoembryonální antigen analýza fyziologie MeSH
- lidé MeSH
- molekuly buněčné adheze nervové analýza fyziologie MeSH
- nádory plic imunologie patologie MeSH
- přežití MeSH
- prognóza MeSH
- protein - isoformy analýza fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- srovnávací studie MeSH
- MeSH
- alely genetika MeSH
- apolipoproteiny E fyziologie MeSH
- ateroskleróza etiologie metabolismus MeSH
- lidé MeSH
- lipoprotein (a) fyziologie MeSH
- protein - isoformy fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
