PURPOSE: Pediatric sarcomas are bone and soft tissue tumors that often exhibit high metastatic potential and refractory stem-like phenotypes, resulting in poor outcomes. Aggressive sarcomas frequently harbor a disrupted p53 pathway. However, whether pediatric sarcoma stemness is associated with abrogated p53 function and might be attenuated via p53 reactivation remains unclear. METHODS: We utilized a unique panel of pediatric sarcoma models and tumor tissue cohorts to investigate the correlation between the expression of stemness-related transcription factors, p53 pathway dysregulations, tumorigenicity in vivo, and clinicopathological features. TP53 mutation status was assessed by next-generation sequencing. Major findings were validated via shRNA-mediated silencing and functional assays. The p53 pathway-targeting drugs were used to explore the effects and selectivity of p53 reactivation against sarcoma cells with stem-like traits. RESULTS: We found that highly tumorigenic stem-like sarcoma cells exhibit dysregulated p53, making them vulnerable to drugs that restore wild-type p53 activity. Immunohistochemistry of mouse xenografts and human tumor tissues revealed that p53 dysregulations, together with enhanced expression of the stemness-related transcription factors SOX2 or KLF4, are crucial features in pediatric osteosarcoma, rhabdomyosarcoma, and Ewing's sarcoma development. p53 dysregulation appears to be an important step for sarcoma cells to acquire a fully stem-like phenotype, and p53-positive pediatric sarcomas exhibit a high frequency of early metastasis. Importantly, reactivating p53 signaling via MDM2/MDMX inhibition selectively induces apoptosis in aggressive, stem-like Ewing's sarcoma cells while sparing healthy fibroblasts. CONCLUSIONS: Our results indicate that restoring canonical p53 activity provides a promising strategy for developing improved therapies for pediatric sarcomas with unfavorable stem-like traits.

• Klíčová slova
• Cancer stemness, Pediatric sarcomas, Prognosis, Targeted therapy, p53,
• MeSH
• dítě MeSH
• Krüppel-like faktor 4 * MeSH
• lidé MeSH
• mladiství MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové kmenové buňky * metabolismus   patologie   MeSH
• nádorový supresorový protein p53 * metabolismus   genetika   MeSH
• předškolní dítě MeSH
• regulace genové exprese u nádorů MeSH
• sarkom * genetika   patologie   metabolismus   MeSH
• signální transdukce MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• myši MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• KLF4 protein, human MeSH Prohlížeč
• Klf4 protein, mouse MeSH Prohlížeč
• Krüppel-like faktor 4 * MeSH
• nádorový supresorový protein p53 * MeSH

Infrequent and rare genetic variants in the human population vastly outnumber common ones. Although they may contribute significantly to the genetic basis of a disease, these seldom-encountered variants may also be miss-identified as pathogenic if no correct references are available. Somatic and germline TP53 variants are associated with multiple neoplastic diseases, and thus have come to serve as a paradigm for genetic analyses in this setting. We searched 14 independent, globally distributed datasets and recovered TP53 SNPs from 202,767 cancer-free individuals. In our analyses, 19 new missense TP53 SNPs, including five novel variants specific to the Asian population, were recurrently identified in multiple datasets. Using a combination of in silico, functional, structural, and genetic approaches, we showed that none of these variants displayed loss of function compared to the normal TP53 gene. In addition, classification using ACMG criteria suggested that they are all benign. Considered together, our data reveal that the TP53 coding region shows far more polymorphism than previously thought and present high ethnic diversity. They furthermore underline the importance of correctly assessing novel variants in all variant-calling pipelines associated with genetic diagnoses for cancer.

• MeSH
• geny p53 genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé MeSH
• missense mutace genetika   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• nádory genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH

Chronic lymphocytic leukemia is associated with a highly heterogeneous disease course in terms of clinical outcomes and responses to chemoimmunotherapy. This heterogeneity is partly due to genetic aberrations identified in chronic lymphocytic leukemia cells such as mutations of TP53 and/or deletions in chromosome 17p [del(17p)], resulting in loss of one TP53 allele. These aberrations are associated with markedly decreased survival and predict impaired response to chemoimmunotherapy thus being among the strongest predictive markers guiding treatment decisions in chronic lymphocytic leukemia. Clinical trials demonstrate the importance of accurately testing for TP53 aberrations [both del(17p) and TP53 mutations] before each line of treatment to allow for appropriate treatment decisions that can optimize patients' outcomes. The current report reviews the diagnostic methods to detect TP53 disruption better, the role of TP53 aberrations in treatment decisions and current therapies available for patients with chronic lymphocytic leukemia carrying these abnormalities. The standardization in sequencing technologies for accurate identification of TP53 mutations and the importance of continued evaluation of TP53 aberrations throughout initial and subsequent lines of therapy remain unmet clinical needs as new therapeutic alternatives become available.

• MeSH
• chromozomální delece * MeSH
• chronická lymfatická leukemie diagnóza   genetika   terapie   MeSH
• lidé MeSH
• lidské chromozomy, pár 17 genetika   MeSH
• mutace * MeSH
• nádorový supresorový protein p53 genetika   MeSH
• přežití bez známek nemoci MeSH
• prognóza MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH

We performed comprehensive molecular analysis of five cases of metastasizing uveal malignant melanoma (UM) (fresh-frozen samples) with an NGS panel of 73 genes. A likely pathogenic germline TP53 mutation c.760A > G (p.I254V) was found in two tumor samples and matched nontumor tissue. In three cases, pathogenic BAP1 mutation was detected together with germline missense variants of uncertain significance in ATM. All cases carried recurrent activating GNAQ or GNA11 mutation. Moreover, we analyzed samples from another 16 patients with primary UM by direct Sanger sequencing focusing only on TP53 coding region. No other germline TP53 mutation was detected in these samples. Germline TP53 mutation, usually associated with Li-Fraumeni syndrome, is a rare event in UM. To the best of our knowledge, only one family with germline TP53 mutation has previously been described. In our study, we detected TP53 mutation in two patients without known family relationship. The identification of germline aberrations in TP53 or BAP1 is important to identify patients with Li-Fraumeni syndrome or BAP1 cancer syndrome, which is also crucial for proper genetic counseling.

• MeSH
• ATM protein genetika   MeSH
• dospělí MeSH
• genetická predispozice k nemoci MeSH
• lidé středního věku MeSH
• lidé MeSH
• melanom genetika   patologie   MeSH
• míra přežití MeSH
• mladý dospělý MeSH
• mutační analýza DNA MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádorový supresorový protein p53 genetika   MeSH
• nádory jater genetika   sekundární   MeSH
• nádory uvey genetika   patologie   MeSH
• prognóza MeSH
• senioři MeSH
• thiolesterasa ubikvitinu genetika   MeSH
• uveální melanom MeSH
• zárodečné mutace * MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ATM protein, human MeSH Prohlížeč
• ATM protein MeSH
• BAP1 protein, human MeSH Prohlížeč
• nádorové supresorové proteiny MeSH
• nádorový supresorový protein p53 MeSH
• thiolesterasa ubikvitinu MeSH
• TP53 protein, human MeSH Prohlížeč

In chronic lymphocytic leukemia (CLL), TP53 gene defects, due to deletion of the 17p13 locus and/or mutation(s) within the TP53 gene, are associated with resistance to chemoimmunotherapy and a particularly dismal clinical outcome. On these grounds, analysis of TP53 aberrations has been incorporated into routine clinical diagnostics to improve patient stratification and optimize therapeutic decisions. The predictive implications of TP53 aberrations have increasing significance in the era of novel targeted therapies, i.e., inhibitors of B-cell receptor (BcR) signaling and anti-apoptotic BCL2 family members, owing to their efficacy in patients with TP53 defects. In this report, the TP53 Network of the European Research Initiative on Chronic Lymphocytic Leukemia (ERIC) presents updated recommendations on the methodological approaches for TP53 mutation analysis. Moreover, it provides guidance to ensure that the analysis is performed in a timely manner for all patients requiring treatment and that the data is interpreted and reported in a consistent, standardized, and accurate way. Since next-generation sequencing technologies are gaining prominence within diagnostic laboratories, this report also offers advice and recommendations for the interpretation of TP53 mutation data generated by this methodology.

• MeSH
• chronická lymfatická leukemie genetika   MeSH
• geny p53 genetika   MeSH
• lidé MeSH
• mutační analýza DNA metody   MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• směrnice pro lékařskou praxi MeSH
• Geografické názvy
• Evropa MeSH