The levels of cell free circulating tumor DNA (ctDNA) in plasma correlated with treatment response and outcome in systemic lymphomas. Notably, in brain tumors, the levels of ctDNA in the ...cerebrospinal fluid (CSF) are higher than in plasma. Nevertheless, their role in central nervous system (CNS) lymphomas remains elusive. We evaluated the CSF and plasma from 19 patients: 6 restricted CNS lymphomas, 1 systemic and CNS lymphoma, and 12 systemic lymphomas. We performed whole exome sequencing or targeted sequencing to identify somatic mutations of the primary tumor, then variant-specific droplet digital PCR was designed for each mutation. At time of enrolment, we found ctDNA in the CSF of all patients with restricted CNS lymphoma but not in patients with systemic lymphoma without CNS involvement. Conversely, plasma ctDNA was detected in only 2/6 patients with restricted CNS lymphoma with lower variant allele frequencies than CSF ctDNA. Moreover, we detected CSF ctDNA in 1 patient with CNS lymphoma in complete remission and in 1 patient with systemic lymphoma, 3 and 8 months before CNS relapse was confirmed; indicating CSF ctDNA might detect CNS relapse earlier than conventional methods. Finally, in 2 cases with CNS lymphoma, CSF ctDNA was still detected after treatment even though a complete decrease in CSF tumor cells was observed by flow cytometry (FC), indicating CSF ctDNA better detected residual disease than FC. In conclusion, CSF ctDNA can better detect CNS lesions than plasma ctDNA and FC. In addition, CSF ctDNA predicted CNS relapse in CNS and systemic lymphomas.
Abstract
The molecular characterisation of medulloblastoma, the most common paediatric brain tumour, is crucial for the correct management and treatment of this heterogenous disease. However, ...insufficient tissue sample, the presence of tumour heterogeneity, or disseminated disease can challenge its diagnosis and monitoring. Here, we report that the cerebrospinal fluid (CSF) circulating tumour DNA (ctDNA) recapitulates the genomic alterations of the tumour and facilitates subgrouping and risk stratification, providing valuable information about diagnosis and prognosis. CSF ctDNA also characterises the intra-tumour genomic heterogeneity identifying small subclones. ctDNA is abundant in the CSF but barely present in plasma and longitudinal analysis of CSF ctDNA allows the study of minimal residual disease, genomic evolution and the characterisation of tumours at recurrence. Ultimately, CSF ctDNA analysis could facilitate the clinical management of medulloblastoma patients and help the design of tailored therapeutic strategies, increasing treatment efficacy while reducing excessive treatment to prevent long-term secondary effects.
The detailed molecular characterization of lethal cancers is a prerequisite to understanding resistance to therapy and escape from cancer immunoediting. We performed extensive multi-platform ...profiling of multi-regional metastases in autopsies from 10 patients with therapy-resistant breast cancer. The integrated genomic and immune landscapes show that metastases propagate and evolve as communities of clones, reveal their predicted neo-antigen landscapes, and show that they can accumulate HLA loss of heterozygosity (LOH). The data further identify variable tumor microenvironments and reveal, through analyses of T cell receptor repertoires, that adaptive immune responses appear to co-evolve with the metastatic genomes. These findings reveal in fine detail the landscapes of lethal metastatic breast cancer.
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•Genomic and transcriptomic landscapes for 10 lethal breast cancers•Within a patient, metastases group in limited clades with shared genomic ancestry•Tumor immune microenvironments across metastases are not uniform•Phylogenetic trees are correlated with TIL-TCR trees across metastases
De Mattos-Arruda et al. profiled multiple metastases from autopsies of patients with therapy-resistant breast cancer, showing that multi-clonal spreading occurs in a small number of founder events. The analysis characterizes predicted neo-antigen landscapes, tumor microenvironments, and accumulation of HLA LOH. T cell immune responses appear to co-evolve with metastatic cancer genomes.
Aim: To evaluate the efficacy of the self-management of insulin titration based on information received by the Short Message Service (SMS). Methods: A case-control study including 59 subjects in each ...arm with 16 weeks of follow-up was performed. The inclusion criteria were: (1) Subjects with type 2 diabetes (T2D) under basal insulin treatment; (2) Suboptimal glycemic control: HbA1c ≥ 7.5% and fasting capillary blood glucose (FCBG) > 140 mg/dL (>3 times per week). Subjects were invited to use an insulin titration service based on SMS feedback aimed at optimizing glycemic control depending on fasting blood glucose levels. Psychological aspects were evaluated in the interventional group by means of validated questionnaires (DDS, HADS and SF-12). Results: The intervention group achieved a lower mean FCBG (126 mg/dL ± 34 vs. 149 mg/dL ± 46, p = 0.001) and lower HbA1c (7.5% ± 1.3 vs. 7.9% ± 0.9, p = 0.021) than the control group. In addition, the intervention group showed a significant improvement in psychological aspects related to Emotional Burden (p = 0.031), Regimen Distress (p < 0.001), Depression (p = 0.049) and Mental Health (p < 0.01). Conclusions: The SMS-guided titration was effective in terms of improving glucometric parameters in comparison with the standard of care and improved significant psychological aspects—mainly, the stress associated with insulin treatment
Epigenetic deregulation revealed by altered profiles of DNA methylation and histone modifications is a frequent event in cancer cells and results in abnormal patterns of gene expression. Cancer ...silenced genes constitute prime therapeutic targets and considerable progress has been made in the epigenetic characterization of the chromatin scenarios associated with their inactivation and drug induced reactivation. Despite these advances, the mechanisms involved in the maintenance or resetting of epigenetic states in both physiological and pharmacological situations are poorly known. To get insights into the dynamics of chromatin regulation upon drug-induced reactivation, we have investigated the epigenetic profiles of two chromosomal regions undergoing long range epigenetic silencing in colon cancer cells in time-course settings after exposure of cells to chromatin reactivating agents. The DNA methylation states and the balance between histone H3K4 methylation and H3K27 methylation marks clearly define groups of genes with alternative responses to therapy. We show that the expected epigenetic remodeling induced by the reactivating drugs, just achieves a transient disruption of the bivalent states, which overcome the treatment and restore the transcriptional silencing approximately four weeks after drug exposure. The interplay between DNA methylation and bivalent histone marks appears to configure a plastic but stable chromatin scenario that is fully restored in silenced genes after drug withdrawal. These data suggest that improvement of epigenetic therapies may be achieved by designing strategies with long lasting effects.
Unlike core histones, the linker histone H1 family is more evolutionarily diverse, and many organisms have multiple H1 variants or subtypes. In mammals, the H1 family includes seven somatic H1 ...variants; H1.1 to H1.5 are expressed in a replication-dependent manner, whereas H1.0 and H1X are replication-independent. Using ChIP-sequencing data and cell fractionation, we have compared the genomic distribution of H1.0 and H1X in human breast cancer cells, in which we previously observed differential distribution of H1.2 compared with the other subtypes. We have found H1.0 to be enriched at nucleolus-associated DNA repeats and chromatin domains, whereas H1X is associated with coding regions, RNA polymerase II-enriched regions, and hypomethylated CpG islands. Further, H1X accumulates within constitutive or included exons and retained introns and toward the 3′ end of expressed genes. Inducible H1X knockdown does not affect cell proliferation but dysregulates a subset of genes related to cell movement and transport. In H1X-depleted cells, the promoters of up-regulated genes are not occupied specifically by this variant, have a lower than average H1 content, and, unexpectedly, do not form an H1 valley upon induction. We conclude that H1 variants are not distributed evenly across the genome and may participate with some specificity in chromatin domain organization or gene regulation.
Background: There are seven histone H1 variants in somatic mammalian cells, two of which are replication-independent, H1.0 and H1X.
Results: In breast cancer cells, H1.0 is enriched at nucleolus-associated domains, whereas H1X is associated with RNA polymerase II-enriched regions.
Conclusion: Most H1 variants show great redundancy across the genome, but there is also some specificity.
Significance: Some H1 variants may have specific functions.
There are seven linker histone variants in human somatic cells (H1.0 to H1.5 and H1X), and their prevalence varies as a function of cell type and differentiation stage, suggesting that the different ...variants may have distinct roles. We have revisited this notion by using new methodologies to study pluripotency and differentiation, including the in vitro differentiation of human embryonic stem (ES) and teratocarcinoma cells and the reprogramming of keratinocytes to induced pluripotent stem cells. Our results show that pluripotent cells (PCs) have decreased levels of H1.0 and increased levels of H1.1, H1.3, and H1.5 compared with differentiated cells. PCs have a more diverse repertoire of H1 variants, whereas in differentiated cells, H1.0 expression represents ∼80% of the H1 transcripts. In agreement with their prevalent expression in ES cells, the regulatory regions of H1.3 and H1.5 genes were found to be occupied by pluripotency factors. Moreover, the H1.0 gene promoter contains bivalent domains (H3K4me2 and H3K27me3) in PCs, suggesting that this variant is likely to have an important role during differentiation. Indeed, the knockdown of H1.0 in human ES did not affect self-renewal but impaired differentiation. Accordingly, H1.0 was recruited to the regulatory regions of differentiation and pluripotency genes during differentiation, confirming that this histone variant plays a critical role in the regulation of these genes. Thus, histone H1 variant expression is controlled by a variety of mechanisms that produce distinct but consistent H1 repertoires in pluripotent and differentiated cells that appear critical to maintain the functionality of such cells.
Large chromosomal regions can be suppressed in cancer cells as denoted by hypermethylation of neighbouring CpG islands and downregulation of most genes within the region. We have analysed the extent ...and prevalence of long-range epigenetic silencing at 2q14.2 (the first and best characterised example of coordinated epigenetic remodelling) and investigated its possible applicability as a non-invasive diagnostic marker of human colorectal cancer using different approaches and biological samples. Hypermethylation of at least one of the CpG islands analysed (EN1, SCTR, INHBB) occurred in most carcinomas (90%), with EN1 methylated in 73 and 40% of carcinomas and adenomas, respectively. Gene suppression was a common phenomenon in all the tumours analysed and affected both methylated and unmethylated genes. Detection of methylated EN1 using bisulfite treatment and melting curve (MC) analysis from stool DNA in patients and controls resulted in a predictive capacity of, 44% sensitivity in positive patients (27% of overall sensitivity) and 97% specificity. We conclude that epigenetic suppression along 2q14.2 is common to most colorectal cancers and the presence of a methylated EN1 CpG island in stool DNA might be used as biomarker of neoplastic disease.
•Human histone H1.2 T165 is phosphorylated at S and G2/M phases of the cell cycle.•H1.2 T165 phosphorylation marks highly proliferative cancer cells.•H1.2 T165 is dispensable for cell proliferation ...and H1.2 binding to chromatin.•H1.4 S27 is phosphorylated at G2/M whether adjacent K26 is modified or not.•H1.4 K26 residue is required for cell proliferation and heterochromatin loading.
In mammals, the linker histone H1, involved in DNA packaging into chromatin, is represented by a family of variants. H1 tails undergo post-translational modifications (PTMs) that can be detected by mass spectrometry. We developed antibodies to analyze several of these as yet unexplored PTMs including the combination of H1.4 K26 acetylation or trimethylation and S27 phosphorylation. H1.2-T165 phosphorylation was detected at S and G2/M phases of the cell cycle and was dispensable for chromatin binding and cell proliferation; while the H1.4-K26 residue was essential for proper cell cycle progression. We conclude that histone H1 PTMs are dynamic over the cell cycle and that the recognition of modified lysines may be affected by phosphorylation of adjacent residues.
Methylation markers have shown promise in the early diagnosis of pancreatic carcinoma. The aim of this study was to assess the diagnostic utility of hypermethylation status of candidate genes in ...combination with KRAS mutation detection in the evaluation of pancreatic masses.
Sixty-one fine needle aspirates of pancreatic masses (43 pancreatic adenocarcinomas and 18 chronic pancreatitis) were studied. Methylation status of HRH2, EN1, SPARC, CDH13 and APC were analysed using melting curve analysis after DNA bisulfite treatment. KRAS mutations were also analysed.
The methylation panel had a sensitivity of 73% (27 of 37, CI 95% 56 to 86%) and a specificity of 100% whenever two or more promoters were found hypermethylated. KRAS mutations showed a sensitivity of 77% (33 of 43, CI 95% 62 to 88%) and a specificity of 100%. Both molecular analyses added useful information to cytology by increasing the number of informative cases. When genetic and epigenetic analyses were combined sensitivity was 84% (36 of 43 CI 95% 69 to 93%) maintaining a 100% specificity.
Analysis of hypermethylation status of a panel of genes and KRAS mutation detection offer a similar diagnostic yield in the evaluation of pancreatic masses. The combined molecular analysis increases the number of informative cases without diminishing specificity.
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