ABSTRACT
Mutation is a fundamental process in tumorigenesis. However, the degree to which the rate of somatic mutation varies across the human genome and the mechanistic basis underlying this variation remain to be fully elucidated. Here, we performed a cross-cancer comparison of 402 whole genomes comprising a diverse set of childhood and adult tumors, including both solid and hematopoietic malignancies. Surprisingly, we found that the inactive X chromosome of many female cancer genomes accumulates on average twice and up to four times as many somatic mutations per megabase, as compared to the individual autosomes. Whole-genome sequencing of clonally expanded hematopoietic stem/progenitor cells (HSPCs) from healthy individuals and a premalignant myelodysplastic syndrome (MDS) sample revealed no X chromosome hypermutation. Our data suggest that hypermutation of the inactive X chromosome is an early and frequent feature of tumorigenesis resulting from DNA replication stress in aberrantly proliferating cells.
Subject(s)
Chromosomes, Human, X , Mutation , Neoplasms/genetics , X Chromosome Inactivation , Adult , Aged , DNA Replication , Female , Humans , Male , Medulloblastoma/genetics , Medulloblastoma/pathology , Myelodysplastic Syndromes/genetics , Myelodysplastic Syndromes/pathology , Polymorphism, Single Nucleotide , S PhaseABSTRACT
INTRODUCTION: It is unknown whether intraoperative subcutaneous wound closing culture samples (WCCS) are useful to predict periprosthetic joint infection (PJI). METHOD: Here we prospectively followed 167 out of a total of 175 consecutive patients with primary total hip (THR) or knee replacement (TKR) between 01/2002 and 12/2002 for a mean follow-up period of 5 years; of those patients, n = 159 (96.8%) underwent WCCS. RESULTS: The results showed a positive WCCS in n = 9 cases (5.8%). Nine patients developed postoperative wound complication and required revision surgery. Two patients developed signs of a deep periprosthetic infection; however, only one out of nine patients had initial positive WCCS. CONCLUSION: Our results thus indicate that WCCS during primary joint replacement is not an appropriate predictive method to identify patients at risk for periprosthetic joint infections.