Periodic Reporting for period 3 - PATRES-MDS (Pathogenesis and treatment of splicing factor mutant myelodysplastic syndromes)
Período documentado: 2022-05-01 hasta 2023-10-31
The myelodysplastic syndromes (MDS) are a group of haematological malignancies that affect 5 per 100,000 people each year. The annual incidence of MDS rises with age reaching 30 per 100,000 for those aged 70 years or older. Unfortunately, despite the development of some new treatments, the MDS remain lethal to the majority of sufferers. The only potentially curative treatment for MDS is blood stem cell transplantation (also known as bone marrow transplantation), but this toxic therapy is appropriate only for a small minority of patients. Therefore, the MDS represent an important unmet clinical need and the development of new effective and non-toxic treatments is urgently required. An improved understanding of how and why the MDS develop can help develop effective new treatments. Like all cancers, the MDS are driven by specific DNA gene mutations in blood-making cells (also known as blood stem cells). It is widely accepted that these mutations give a growth advantage to the host cells, however the nature and biological basis of this advantage remain elusive. The most common type of MDS-driver mutations affect genes involved in a process called RNA splicing, a necessary step for the production of mature RNA in cells. Such mutations usually affect the SF3B1 and SRSF2 genes, are found in more than two thirds of MDS cases and are usually responsible for initiating the process of MDS development. In fact, splicing gene mutations can be found in the blood for several years before MDS develop, and drive expansion of the mutant cells specifically in older people for reasons that remain unknown. Notably, as the proportion of people surviving to advanced old age increases, so does the incidence of MDS. The overall objectives of this project are to decipher how mutations in splicing genes SF3B1 and SRSF2 lead to clonal expansion and the development of MDS in older age, and how potential new treatments can reverse the effects of these mutations or eliminate the cells carrying them. We anticipate that our studies will help the development of improved treatments for patients with MDS that will prolong their life and/or cure them from these diseases.
Overall, we are now poised to carry out our planned investigations and anticipate that over the next 1-2 years we will make new discoveries that will help us understand how splicing genes mutations cause MDS and give us hints about potential treatment for these disorders.
Since the start of this project in May 2019 we have been able to generate many of the tools, protocols, reagents and models that will enable us to perform the most appropriate studies for understanding the effects of splicing gene mutations. Overall, we have been able to make good progress towards our goals, including:
1. Using state-of-the-art genome editing, we have introduced MDS-associated mutations in splicing genes in blood cell lines and are now using these for downstream studies to determine the effects of these mutations on blood cells
2. We have generated two new mouse models and have started using these to study the mutations in vivo, in a way that closely mimics what happens in humans with MDS and obviates the need for (unphysiological) haematopoietic stem and progenitor cell (HSPC) transplantation.
3. We have tested pro-inflammatory treatments to mimic ageing-related inflammation in mice repopulated with cells carrying normal and Sf3b1-mutant cells.
4. We have obtained ethical approval and set up a process to systematically collect samples from patient volunteers at Cambridge University Hospitals. Samples obtained are being used in experimental studies and will be used for validation of findings from proteomic, mouse and other experiments/work (e.g. see next point).
5. Using published molecular gene expression data, we have a set of mRNA transcripts that code for cell surface proteins and are differentially expressed in MDS patient blood cells. We have been investigate the ability of these cell surface proteins to distinguish mutant for wild type cells, which would be of great help to our studies.
Overall, we are now poised to carry out our planned investigations and anticipate that over the next 1-2 years we will make new discoveries that will help us understand how splicing genes mutations cause MDS and give us insights into potential treatments for these disorders.
Since the start of this project in May 2019 we have been able to generate many of the tools, protocols, reagents and models that will enable us to perform the most appropriate studies for understanding the effects of splicing gene mutations. Overall, we have been able to make good progress towards our goals, including:
1. Using state-of-the-art genome editing, we have introduced MDS-associated mutations in splicing genes in blood cell lines and are now using these for downstream studies to determine the effects of these mutations on blood cells
2. We have generated two new mouse models and have started using these to study the mutations in vivo, in a way that closely mimics what happens in humans with MDS and obviates the need for (unphysiological) haematopoietic stem and progenitor cell (HSPC) transplantation.
3. We have tested pro-inflammatory treatments to mimic ageing-related inflammation in mice repopulated with cells carrying normal and Sf3b1-mutant cells.
4. We have obtained ethical approval and set up a process to systematically collect samples from patient volunteers at Cambridge University Hospitals. Samples obtained are being used in experimental studies and will be used for validation of findings from proteomic, mouse and other experiments/work (e.g. see next point).
5. Using published molecular gene expression data, we have a set of mRNA transcripts that code for cell surface proteins and are differentially expressed in MDS patient blood cells. We have been investigate the ability of these cell surface proteins to distinguish mutant for wild type cells, which would be of great help to our studies.
Overall, we are now poised to carry out our planned investigations and anticipate that over the next 1-2 years we will make new discoveries that will help us understand how splicing genes mutations cause MDS and give us insights into potential treatments for these disorders.
A key deliverable that goes beyond the current state-of-the-art has been the generation of murine models that will enable the generation of endogenous hematopoietic mosaicism with only a proportion (<50%) of the cells carrying genetic mutations of choice. This approach avoids the toxic effects of blood stem cell transplantation (current state-of-the-art) and allows a much more physiological study of the mutations under study, in the presence and absence of relevant modifiers, perturbations or treatments. Together with other advances we expect that these innovative new models will help us: i) derive new insights into how mutations in splicing factor genes (SF3B1 & SRSF2) drive the abnormal growth of mutant blood stem and progenitor cells and ii) identify therapeutic vulnerabilities of MDS driven by these mutations that will be used for the development of new treatment against these incurable malignancies.