Inactivating mutations in BRCA1 or BRCA2 genes predispose to several types of cancer.

What is the most effective way to eliminate tumour cells? The DNA repair mechanism could play an important role in increasing the effectiveness of chemotherapy in the fight against cancerous cells. If we are to influence this mechanism, we need fundamental knowledge about how the mechanism works.

Promotores: J.N. Kok, H.J. Hoogeboom

Promotor: P. J. J. Hooykaas Co-promotor: B. S de Pater

Identification and characterization of components of DNA repair pathways and their role in Agrobacterium T-DNA integration and repair of CRISPR/Cas induced DSBs.

Promotor: D. Bouwmeester, Co-promotor: D. Kraft

The type-IV secretion system (T4SS) is a machinery able to transfer DNA and proteins between bacteria and in certain cases also to eukaryotic cells.

Our DNA molecules are packaged by proteins in compact structures. The aim of this project is to understand how modern gene editing techniques nevertheless get access to their target in the DNA.

Promotor: R.D. Gill, F. Taroni

THURSDAY, 19 JANUARY 2023 FROM 18:00-19:00 UTC+02

The genetic information of all living organisms is contained in their DNA. Cells modify the degree of DNA compaction by epigenetics, which largely determines what genes are read out and which genes are transcriptionally silent.

All life on earth contains DNA, which is used to store biological information. Organisms compact their DNA in order for it to fit inside their cell(s).

How can we prevent drug-induced liver and kidney damage? PhD candidates Marije Niemeijer and Lukas Wijaya investigated what happens in the cells during the onset of this damage: a stress response. Both focused on a different subtopic and made some interesting discoveries.

On 17 December 2018, Dejian Kong defended his thesis 'Civil Liability for Damage caused by Global Navigation Satellite System'. The doctoral research was supervised by Prof. dr. P.M.J. Mendes de Leon.

Bacteria often experience external challenges, such as changes in environmental conditions or attacks by bacteriophages.

PhD defence

DNA carries various forms of information. Out of these forms of information the most well-known is classical genetic information.

Leiden physicist Maarten Kruithof has discovered how our DNA is infallibly able to fold itself and to unfold again. In his dissertation he demonstrates how DNA is folded in a single long, very flexible spiral.

Cellular stress response pathways are activated upon exposure to chemicals and help organisms deal with various molecular dangers (e.g. oxidative stress). When these pathways become hyper-activated an adverse response takes place and cells die, which may lead to organism-level toxicity such as drug-induced…

Lecture

Single-celled organisms have stiffer DNA than multicellular lifeforms like humans and rice. Theoretical physicists managed to simulate the folding in full genomes for the first time to reach this conclusion. Publication in Biophysical Journal on February 7.

This project aims to assess the risk of spread of antimicrobial resistance genes in the environment derived from currently used synthetic biology approaches in the field of drug discovery.

Dutch researchers have developed a new tool to label DNA for studying chromosomes in live cells. The tool is non-invasive and can be applied in culture but also in living organisms, such as zebrafish embryos. The team published their findings in the journal Nucleic Acids Research.

PhD defence

PhD defence

PhD defence

PhD defence

In an Advance Online Publication biophysicist John van Noort and others show using magnetic tweezers that DNA is folded in compliant helices of chromatin. This allows enzymes access to the DNA needed for gene expression. Van Noort's research group made the discovery in close partnership with researchers…

Theoretical physicist Helmut Schiessel receives an NWO Projectruimte grant of 390,000 euro. He will use this budget to hire a postdoc and a PhD student to continue his research on flexibility of double stranded DNA.

Schneider

Promotor: B. van de Water

An overview of the research at the Cancer Dug Target Discovery group.

The four possible segments A, T, C and G that link together to form DNA molecules, and with their ordering encode genetic information, are not only different in name, but also in their physical and chemical properties.

The DNA of young people is regulated to express the right genes at the right time. With the passing of years, the regulation of the DNA gradually gets disrupted, which is an important cause of ageing. A study of over 3,000 people shows that this is not true for everyone: there are people whose DNA appears…

Using the principles of Industrial Ecology in Environmental Policy making in two cases: transition to a hydrogen economy and chlorinated compounds.

Researching DNA material for genetic disorders using the most powerful apparatus. This is what GenomeScan, a company on the Leiden Bio Science Park, does. Master's student Konstantina Konstantinopoulou is doing an internship there. 'It's a world where developments happen really rapidly so it's a fantastic…

Effective host defence against tuberculosis bacteria depends on a properly balanced level of inflammation. The Inflammafish project uses zebrafish larvae to study how autophagy controls this inflammation and vice versa.

Phosphorylation affects all four major biomolecules – proteins, lipids, carbohydrates and nucleic acids – and plays a pivotal role in the most fundamental cellular functions.

Key publications of the Cancer Drug Target Discovery group

The main purpose of DNAmarkerpoint is to better understand the ecology, evolution and biodiversity through the study of ancient- and modern DNA.

Why do opposites attract? According to Karin van der Tuin, researcher at Leiden University Medical Center (LUMC), it could be because of your DNA. The more you differ from one another, the better. She will be testing her ideas at the Lowlands festival Lowlands, where she will subject visitors to DNA…

Self-assembly is an abundant process in nature and is vital to many processes in living organisms.

Leiden and Jülich researchers discovered an elegant and simple approach to improve the sensitivity of graphene biosensors. These so-called ‘next generation graphene electronic biochemical sensor devices’ are able to detect very low amounts of HIV DNA thanks to their very low electronic noise.

Rapid developments in DNA techniques allow researchers to find out more and more about human genetics. An international group of scientists has drawn up five ethical guidelines to ensure that this DNA research is better regulated. Leiden archaeologist Marie Soressi – one of the signatories - explains…

Leiden theoretical physicists have proven that not only the genetic information in DNA determines who we are, but also DNA’s mechanics. Helmut Schiessel and his group simulated many DNA sequences and found a correlation between mechanical cues and the way DNA is folded. Publication in PLoS One.

Freshwater is an important resource, but at a great risk of species decline due to habitat loss, pollution and over-exploitation, and invasive alien species.

The way DNA folds, largely determines which genes are read out. John van Noort and his group have quantified how easily rolled-up DNA parts stack. This costs less energy than previously assumed. Publication in Biophysical Journal.

You pour a scoop of ditch water in the DNA scanner, and voilà: you know exactly which plants and animals the ditch accommodates. Well, it is not that simple yet, but according to PhD candidate Kevin Beentjes, we can already use DNA techniques to monitor the quality of freshwater. For his PhD research,…

PhD student Willem Noteborn has investigated supramolecular structures. These can be useful for the loading of medicines and signalling molecules regarding, for example, cellular differentiation. In his thesis, he describes the functioning of these structures.