DNA DAMAGE - RNAI · Identification and characterization of novel genes involved in DNA damage- response pathways in humans
FP6 — Marie Curie Actions (Human Resources and Mobility)
- Duration
- 2005-01-01 → 2006-12-31
- EU contribution
- €150,977
- Participants
- 1
- Scheme
- EIF
Lines connect the coordinator with its partners.
Results in brief
Final Activity Report Summary - DNA DAMAGE - RNAi (Identification and characterization of novel genes involved in DNA damage- response pathways in humans)
In the scientific project described here, I identified microRNA genes (miRNAs, miRs) that are potent promoters of human cancers. miRNA genes encode short RNAs that are widely expressed in multi-cellular organisms. They suppress the expression of protein coding-genes, which encode messenger RNAs (mRNAs) that bear fully or partially complementary sequences to that of the miRNAs. Typically, hundreds of potential protein coding target genes are predicted for each miRNA. While approximately 450 human miRNA genes were found so far, the function of only a handful of them has been determined. We recently performed a functional genetic screen for miRNAs that mediate bypass of cellular senescence, induced by the activation of cancer promoting genes (oncogenes). (Senescence is a cancer defence mechanism, which leads to proliferation arrest and eventually cell death.) We discovered that miR-372 and miR-373 can induce the tumourigenic transformation of primary (non-cancerous) human cells, and described their involvement in the development of testicular germ cell tumours. Our experiments demonstrated the power of miRNAs to change cellular fate, and exemplified the potential of miRNA-genetic screens to identify cancer relevant genes. In order to identify and characterise miRNAs that are potential oncogenes, I performed a large-scale assay, in which I introduced into primary cells each of the known human miRNA genes, and examined their capacity to promote the tumourigenic transformation of these cells. I performed experiments to identify relevant target genes to the miRNAs identified in the screen, using target-predicting software and different experimental approaches that can select for possible target mRNA-candidates. Furthermore, I examined cellular pathways that were affected by these miRNAs, in order to uncover their mechanism of action in promoting human cancer. With the identification of hundreds of miRNAs in the human genome that can potentially target thousands of protein coding genes, only a few of which with a known function, it becomes clear that systematic searches for miRNA functions should be performed. In my research I carried out genetic screens to identify and characterise miRNAs with the capacity to induce transformation of primary human cells. I believe that these experiments will enable us to identify miRNAs with cancer relevant functions and uncover their relevant target genes and their mechanism of action. The results of this research may contribute to the development of better diagnostic tools and to a better understanding of the efficiency of cancer therapy. In the future, these miRNAs might be used for designing better cancer therapeutics, due to their unique molecular properties (i.e. their small size and molecular specificity).
Data: CORDIS, © European Union
Project objective
DNA damage induces cell cycle arrest, required for the action of repair mechanisms. The genes of these pathways affect cells' sensitivity to DNA damage, and their loss may lead to deregulated cellular growth, genomic instability and cancer. Until now, our knowledge in this field was gained mainly from work in cells of DNA damage-sensitive individuals and from lower eukaryotes. Improving our understanding of these processes in mammals was hampered due to lack of suitable genetic tools. Recently, we developed a vector-based system that generates persistent loss-of-function phenotypes in mammalian cells by production of short interfering RNA (siRNA). A siRNA-expressing library to suppress up to 8000 human genes was constructed in our institute and is consent to perform genome wide loss-of-function screens.The proposal includes:1) Screen for novel genes participating in DNA damage response pathways;2) Elucidating the roles of these genes in DNA damage response pathways;3) Evaluating the contribution of these genes to malignancy.I will screen primary human cells for genes involved in sensitising cells to genotoxic stress, and genes that synergize with radio- and chemotherapy agents in tumour cell killing. I will investigate the mechanism of action of the identified genes in DNA damage response pathways, and will assess their tumour suppressive/oncogenic properties. The identification of novel genes modulating cellular toxicity induced by DNA damage will improve our understanding of the action genotoxic agents, and will provide new opportunities to screen for drugs that sensitise tumours to conventional therapy.This project will render the siRNA library system extremely beneficial for mammalian models and research fields, encouraging the transfer of research competencies across different labs. My training in this project will complement my contemporary expertise and will diversify them considerably, contributing to my development as an independent researcher.
Original text from CORDIS.
Participants
- THE NETHERLANDS CANCER INSTITUTE / ANTONI VAN LEEUWENHOEK HOSPITAL · AMSTERDAMCoordinatorNetherlands
Links
Data: CORDIS, © European Union