Background: DNA methylation patterns are established during development and are propagated in a cell type specific manner, but these patterns may become aberrant during aging and cancer. Regions of alternating high and moderate to low levels of DNA methylation exist along all chromosomes in human cells. It is unclear how these distinct DNA methylation blocks are established. Most of the prior work in this area has been performed with mouse embryonic stem cells.

Methods: Using whole genome bisulfite sequencing and chromatin-immunoprecipitation sequencing, we have profiled DNA methylation at single base resolution and various histone modifications in human bronchial epithelial cells.

Results: We found that many regions of lower DNA methylation (< 50%) are characterized by presence of the Polycomb repressive complex 2 (PRC2) mark, histone H3K27 trimethylation, but less so by the PRC1 mark histone H2AK119 monoubiquitylation. These same PRC2-marked regions also showed a depletion of histone H3K36 di- and tri-methylation.

Conclusion: Since H3K36me2 and H3K36me3 are recognized by the reader domains of the DNA methyltransferases DNMT3A and DNMT3B, and H3K36 methylation is a block to the PRC2 methyltransferases, these two types of crosstalk may explain the stable maintenance and antagonism between H3K27me3 and broad DNA methylation domains. However, methylated CpG islands are depleted of H3K36me2 and show a different relationship between DNA methylation and H3K36me2 deposition compared to non-CpG island regions. The data give insight into how DNA methylation patterns are established in human cells. We discuss these findings and their potential relevance for altered DNA methylation patterns seen in aging tissues and in cancer cells.

Background: The outcomes of older adults with cancer are usually worse than those of their younger counterparts. Several randomised trials have demonstrated benefits of a comprehensive geriatric assessment (CGA) in older patients undergoing systemic cancer therapy. Despite that, CGA is not implemented into routine care in Germany and data on its efficacy and feasibility within the German healthcare system are missing.

Methods: This prospective, bicentric cohort study will assess the feasibility of CGA implementation into routine care for older adults with cancer in Germany. Patients ≥ 65 years with a positive geriatric screening (G8) and newly diagnosed cancer or progressive disease prior to a new treatment line undergo a CGA as part of their routine care. Patients who consent to participate in the study receive a follow-up call after three months to assess functional measures, and their (routine) CGA data are analyzed thereafter. CGA results are presented during the multidisciplinary team meeting to inform treatment recommendations provided by primary healthcare providers (pHCP; e.g., oncologists, gynecologists, urologists). pHCP are further evaluated for their satisfaction with CGA implementation and whether its results have influenced their recommendations. The primary endpoint is to estimate the patients’ willingness to participate with an accuracy of ± 7.5%. Secondary endpoints focus on additional feasibility measures and patient preferences.

Conclusion: This study will assess the feasibility of CGA implementation into routine care for older cancer patients. Its results will provide the framework to design a larger subsequent trial to assess the efficacy and cost effectiveness of CGA implementation in Germany.

Clinical trial registration number: DRKS00035569