Environmental stressors and radiation lead to adverse effects, such as cancer, germ cell mutagenesis and inflammatory responses. The plethora of stressors that humans are constantly exposed to may also disrupt important processes during early development when stem cells are transformed into more dedicated cell types to form a new individual. Moreover during this window of time the expression of our genes (the transcriptome) and regulation of the transcriptome, by epigenetic regulation can be disturbed due to external stressors.

So, cells respond to external stimuli by changing their transcriptional activity, which is regulated by epigenetic mechanisms. These mechanism include processes such as DNA methylation and histone modifications, changing the accessibility to chromatin for transcription. One method that encompass several of the epigenetic regulatory mechanisms is ATAC-seq (Assay for Transposase-Accessible Chromatin using sequencing) which is a technique used to assess genome-wide chromatin accessibility, i.e. identifying regions of the genome that is available for transcription. This method is established in our lab.

Human stem cells are progenitors cells for all cells of the body. We work with human inducible pluripotent stem cells (hIPSC) cells, that are representative stem cells for all cell types of the body and is a model system for early embryonal development and cancer, and investigate detrimental effects on these cells as a result of environmental stressors such as ionising radiation (giving rise to reactive oxygen species) and other environmental stressors, that often occur in symphony (i.e. simultaneously).

Our research group (Department of Environment and Health; Section of Molecular Toxicology) at the Norwegian Institute of Public Health (NIPH) focus on effects of stressors in the environment on genetic and epigenetic regulation, linked to adverse effect and disease outcomes.

This master assignment may include

1. hIPSC cell culturing and characterization suing morphology assessment by microscopy, stem cell factor assessments by real-time q-PCR/fluorescence microscopy and karyotyping
2. Conducting experiments in hIPSC cell cultures exposed to ionizing radiation, alone and in combination with co-stressors), and assess effect markers such as
   1. Cell survival analyses (cytotoxicity)
   2. Changes in differentiation to the three germ cell layers
   3. Genotoxicity and DNA repair dynamics by DNA damage analyses (i.e. comet analyses)
   4. Epigenetic analyses
      1. ATAC seq for chomatin accessibility assessments
      2. Gene expression analyses by q-PCR of mRNA sequencing
      3. Bioinformatic analyses of sequencing data
      4. DNA methylation assessment (EPIC)

For further details please contact

Ann-Karin (Anka) Olsen

Senior Scientist, PhD

Section of Molecular Toxicology

Department of Environmental Health

Norwegian Institute of Public Health (NIPH)

https://www.fhi.no/

Tlf. +47 21076296/92035022