Project description:Therapy-related acute myeloid leukaemia (t-AML) is a late adverse effect of previous chemotherapy(ct-AML) and/or radiotherapy (rt-AML) or immunosuppressive treatment. t-AMLs represent ~10-20% of all AML cases, are extremely aggressive and have a poor prognosis in comparison to de novo AML. We hypothesised that in rt-AML, exposure to radiation leads to genome-wide epigenetic modifications. An epigenome-wide association study was conducted, measuring over 850K methylation sites across the whole genome in 14 donors. We focused on 94K sites lying in CpG-rich gene promoter regions. Overall, we found genome-wide hypo-methylation in AML and identified specific genes with promoter hyper-methylation. Additionally, pyrosequencing was used to quantify the methylation in 24 samples. We confirmed that the promoters of the genes MEST and GATA5, both previously reported as tumour suppressors, were specifically hyper-methylated in rt-AML in comparison to control and other subtypes of t-AML. These may represent the epigenetic contribution to rt-AML development at the molecular level and be potential drug targets in rt-AML.
Project description:Therapy-related acute myeloid leukaemia (t-AML) is a late side effect of previous chemotherapy (ct-AML) and/or radiotherapy (rt-AML) or immunosuppressive treatment. t-AMLs, which account for ∼10-20 % of all AML cases, are extremely aggressive and have a poor prognosis compared to de novo AML. Our hypothesis is that exposure to radiation causes genome-wide epigenetic changes in rt-AML. An epigenome-wide association study was undertaken, measuring over 850K methylation sites across the genome from fifteen donors (five healthy, five de novo, and five t-AMLs). The study predominantly focussed on 94K sites that lie in CpG-rich gene promoter regions. Genome-wide hypomethylation was discovered in AML, primarily in intergenic regions. Additionally, genes specific to AML were identified with promoter hypermethylation. A two-step validation was conducted, both internally, using pyrosequencing to measure methylation levels in specific regions across fifteen primary samples, and externally, with an additional eight AML samples. We demonstrated that the MEST and GATA5 gene promoters, which were previously identified as tumour suppressors, were noticeably hypermethylated in rt-AML, as opposed to other subtypes of AML and control samples. These may indicate the epigenetic involvement in the development of rt-AML at the molecular level and could serve as potential targets for drug therapy in rt-AML.
Project description:gDNA from patient samples with multiple basal cell carcinomas and possible exposure to ionizing radiation was hybridized Vs. GM12878 gDNA to assess CNAs. We aimed to find a possible common aberration pattern related to ionizing radiation or a rare metastasis.
Project description:Tardigrades can survive remarkable doses of ionizing radiation, up to about 1000 times the lethal dose for humans. How they do so is incompletely understood. We found that the tardigrade Hypsibius exemplaris suffers DNA damage upon gamma irradiation, but damage is repaired. We show that tardigrades have a specific and robust response to ionizing radiation: irradiation induces a rapid, dramatic upregulation of many DNA repair genes. By expressing tardigrade genes in bacteria, we validate that increased expression of some repair genes can suffice to increase radiation tolerance. We show that at least one such gene is necessary for tardigrade radiation tolerance. Tardigrades’ ability to sense ionizing radiation and massively upregulate specific DNA repair pathway genes may represent an evolved solution for maintaining DNA integrity.
Project description:Genome-wide expression analysis comparison with and without ionizing radiation in p53 mutant and wild type Drosophila larvae Genome-wide expression analysis comparison with and without ionizing radiation in p53 mutant (p53^5A-1-4) and wild type (y^1 w^1118) Drosophila third instar larvae. 4000R of X-rays used in IR-treated Drosophila. Analyzed 2hr and 18hr after exposure with age-matched larvae in non-treated controls.
Project description:The goal of the study is to identify differentially expressed isoforms in response to SRSF1 knockdown and/or ionizing radiation in HEK293T cells
Project description:This project explored the relationship between ionizing radiation and antigen presentation using both proteomic and immunopeptidomics methodologies. We investigated the radiation-specific changes which occur in the colorectal tumor cell proteome associated with changes in dose and time after irradiation. We used this data to observe the changes in key regulators and effector proteins of the antigen processing and presentation machinery. Furthermore, a parallel immunopeptidomics analysis enabled a peptide-level assessment of antigen presentation to correlate changes observed in the proteome thereby defining a radiation-specific peptide repertoire. A nuanced relationship between protein expression and antigen presentation was observed where radiation-induced changes in proteins do not always correlate with increased presentation of associated peptides. Furthermore, a neoantigen which increases in the context of radiation was characterised. This study provides new insights into how radiation enhances antigen processing and presentation that could be suitable for the development of combinatorial therapies.
Project description:Densely ionizing radiation is a major component of the space radiation environment and has potentially greater carcinogenic effect compared to sparsely ionizing radiation that is prevalent in the terrestrial environment. It is unknown to what extent the irradiated microenvironment contributes to the differential carcinogenic potential of densely ionizing radiation. To address this gap, 10-week old BALB/c mice were irradiated with 100 cGy sparsely ionizing g-radiation or 10, 30, or 80 cGy of densely ionizing, 350 MeV/amu Si particles and transplanted 3 days later with syngeneic Trp53 null mammary fragments. Tumor appearance was monitored for 600 days. Tumors arising in Si-particle irradiated mice had a shorter median time to appearance, grew faster and were more likely to metastasize. Most tumors arising in sham-irradiated mice were ER-positive, pseudo-glandular and contained both basal keratin 14 and luminal keratin 8/18 cells (designated K14/18), while most tumors arising in irradiated hosts were K8/18 positive (designated K18) and ER negative. Comparison of K18 vs K14/18 tumor expression profiles showed that genes increased in K18 tumors were associated with ERBB2 and KRAS while decreased genes overlapped with those down regulated in metastasis and by loss of E-cadherin. Consistent with this, K18 tumors grew faster than K14/18 tumors and more mice with K18 tumors developed lung metastases compared to mice with K14/18 tumors. However, K18 tumors arising in Si-particle irradiated mice grew even faster and were more metastatic compared to control mice. A K18 Si-irradiated host profile was enriched in genes involved in mammary stem cells, stroma, and Notch signaling. Thus systemic responses to densely ionizing radiation enriches for a ER-negative, K18-positive tumor, whose biology is more aggressive compared to similar tumors arising in non-irradiated hosts. Key Words: ionizing radiation; breast cancer; heavy ion radiation;initiation; promotion