Search

Background TP53 is the most frequently mutated gene in the human cancer, and the awareness of its mutational status is useful in the diagnosis and treatment of cancer patients. In the present study, we investigated the association between TP53 gene mutations and p53 immunohistochemical staining (IHC) patterns and non-genetic effect of MDM2 as a negative regulator of p53. Methods A total of 135 solid cancer cases with next generation sequencing data were subjected to p53 IHC and classified as overexpression, null type or usual pattern. Results TP53 mutation was observed in 104 out of 135 cases (77.0%). When the TP53 mutations were annotated into DISRUPTED (truncations, frameshifts, splice site mutations, and deep deletions) and IF-DBD (in-frame mutations in the DNA binding domain), the null type p53 IHC pattern was associated with DISRUPTED mutations (sensitivity 86.2%, specificity 97.2%) while the overexpression pattern was associated with IF-DBD mutations (sensitivity 100%, specificity 81.7%). The specificity of p53 IHC usual pattern predicting wild type TP53 was also as high as 100%. Regardless of MDM2 amplification, p53 IHC pattern showed a perfect association with TP53 mutation pattern. Conclusions p53 IHC pattern (overexpression, null type, usual) reasonably predicted TP53 mutational status (DISRUPTED, IF-DBD), and MDM2 amplification status did not have any impact on the p53 IHC pattern.

Purpose The phase 3 ATTRACTION-2 study demonstrated that nivolumab monotherapy improved survival compared to placebo in patients with pretreated advanced gastric cancer (AGC). However, the efficacy of nivolumab seems to be limited to a subset of patients. Materials and methods The predictive values of blood neutrophil–lymphocyte ratio (NLR), serum Na, PD-L1 expression, MSI status, tumor EBV infection, and tumor mutation burden (TMB) were investigated in patients with AGC refractory to ≥2 lines of chemotherapy enrolled from Asan Medical Center in ATTRACTION-2 study. Results All 45 patients were analyzed; nivolumab (n = 28) and placebo (n = 17) groups. The objective response rate, median progression-free survival (PFS), and overall survival (OS) were 16.7%, 1.6 months, and 8.1 months in nivolumab group and 0%, 1.6 months and 6.5 months in placebo group. When comparing nivolumab with the placebo group, tumor PD-L1 expression, blood NLR, and serum Na were significant predictive factors of PFS and OS. A multivariate analysis revealed that PD-L1 ( +) and low NLR (≤ 2.9, median) were associated with better PFS. In the nivolumab group, PD-L1 ( +), low NLR, and normal Na (≥ 135 mmol/L) were associated with higher response and disease control rates, while tumor EBV infection and TMB were not. Conclusion Tumor PD-L1 expression, blood NLR, and serum Na could be predictive biomarkers for the efficacy of nivolumab in previously treated cases of AGC.

Background There has been a growing interest in the association between mitochondrial dysfunction and sepsis. However, most studies have focused on mitochondrial structural damage, functional aspects, or the clinical phenotypes in sepsis. The purpose of this study was to evaluate mitochondrial DNA (mtDNA) gene mutations in critically ill pediatric patients with septic shock. Method Thirteen patients with severe sepsis or septic shock admitted to the pediatric intensive care unit (PICU) of a tertiary children's hospital were enrolled in this prospective observational study. Clinical data from electronic medical records were obtained. Whole-blood samples were collected within 24 h of PICU admission to perform PBMC isolation, mtDNA extraction, and mtDNA sequencing using next-generation sequencing. Results mtDNA sequencing revealed mutations in 9 of the 13 patients, presenting 27 point mutations overall, with 15 (55.6%) located in the locus related to adenosine triphosphate production and superoxide metabolism, including electron transport. Conclusion In this pilot study, significant numbers of mtDNA point mutations were detected in critically ill pediatric patients with septic shock. These mutations could provide promising evidence for mitochondrial dysfunction in sepsis and a basis for further large-scale studies. Impact This study is the first to examine mitochondrial DNA mutations in pediatric patients with septic shock using next-generation sequencing. A high frequency of mitochondrial DNA mutations was detected in these patients indicating an association with septic shock. This pilot study may provide a potential explanation for the association between mitochondrial dysfunction and septic shock on a genetic basis.

Background The first Korean individual diploid genome sequence data (KOREF) was publicized in December 2008. Results A Korean genome variation analysis and browsing server (Gevab) was constructed as a database and web server for the exploration and downloading of Korean personal genome(s). Information in the Gevab includes SNPs, short indels, and structural variation (SV) and comparison analysis between the NCBI human reference and the Korean genome(s). The user can find information on assembled consensus sequences, sequenced short reads, genetic variations, and relationships between genotype and phenotypes. Conclusion This server is openly and publicly available online at http://koreagenome.org/en/ or directly http://gevab.org.