Periodic Reporting for period 1 - MS (Unravelling the molecular and cellular mechanism of metastasis)
Berichtszeitraum: 2020-01-29 bis 2021-11-28
The Marie Curie fellowship has enabled me to work on fundamental questions related to cancer and metastasis.
Indeed, metastasis is the primary cause of cancer deaths. Yet, for most of cancers, the identification and the mechanisms by which the metastatic initiating cells (MICs) successfully establish a secondary tumor at a distant site from their primary tumor remains elusive.
Understanding these mechanisms is fundamental in developing clinical applications that would enable the treatment of patients suffering from advanced-stage cancers. The understanding of such mechanisms would also enable a preventive approach for cancers detected early enough.
The classical view of the metastatic process posits that MICs need to lose their cell-cell contact with the neighbors, detach from the primary tumor, intravasate into the blood circulation, circulate through the body, stop, extravasate and colonize distant organs, in which they reform a new mass of proliferative cells. With the tremendous heterogeneity of tumors and the limited capacity to trace multiple genetic clones in parallel with the traditional reporter mice , new animal models are needed to better understand the clonal dynamic and molecular mechanisms guiding different steps of the metastatic cascades in vivo.
The overall objective of this project was to to investigate primary tumour heterogeneity and contribution of cancer clones to metastasis, as well as the role of microenvironment in regulating metastasis. This knowledge aids the design of new methods for early diagnosis and the monitoring of patients with metastasis, and will lead to new strategies that target or prevent metastasis.
Indeed, metastasis is the primary cause of cancer deaths. Yet, for most of cancers, the identification and the mechanisms by which the metastatic initiating cells (MICs) successfully establish a secondary tumor at a distant site from their primary tumor remains elusive.
Understanding these mechanisms is fundamental in developing clinical applications that would enable the treatment of patients suffering from advanced-stage cancers. The understanding of such mechanisms would also enable a preventive approach for cancers detected early enough.
The classical view of the metastatic process posits that MICs need to lose their cell-cell contact with the neighbors, detach from the primary tumor, intravasate into the blood circulation, circulate through the body, stop, extravasate and colonize distant organs, in which they reform a new mass of proliferative cells. With the tremendous heterogeneity of tumors and the limited capacity to trace multiple genetic clones in parallel with the traditional reporter mice , new animal models are needed to better understand the clonal dynamic and molecular mechanisms guiding different steps of the metastatic cascades in vivo.
The overall objective of this project was to to investigate primary tumour heterogeneity and contribution of cancer clones to metastasis, as well as the role of microenvironment in regulating metastasis. This knowledge aids the design of new methods for early diagnosis and the monitoring of patients with metastasis, and will lead to new strategies that target or prevent metastasis.
The goals of the project were twofold: first, we aimed at investigating primary tumour heterogeneity and contribution of cancer clones to metastasis. We also worked on understanding the role of microenvironment in regulating metastasis.
With respect to understanding the heterogeneity within the primary tumour and metastasis,
we analysed the barcode-clone composition in the primary tumour and metastases, using DNA/RNA extraction followed by PCR amplification. The samples were submitted for DNA and RNA sequencing. Subsequently, the analysis of the sequencing results has been carried out and we were able to identify barcode structure in primary tumour and metastases, offering an outlook on cellular dynamics during the metastatic process. Analysis of gene expression in different tissues of metastasis allowed us to provide link between the gene expression pattern and the potential of a tumour cell to metastasize. The genes of interest are tested functionally by gain and loss-of function assays.
Regarding the role of microenvironment in the metastatic progression, we applied an unbiased approach of sequencing niche cells from primary tumour and metastasis. To this end we were able to isolate the cells in the immediate surroundings of cancer cells, and the molecular profiling by 10X single-cell RNA-sequencing enabled the identification of broad populations of cells in the environment. We were able to identify populations of cells enriched in the metastases. These findings are essential for the understanding of how the cancer cells may be regulated by other cells in their niche, to drive metastasis.
The work on this project has resulted in one review article on this topic (Sznurkowska and Aceto 2021) and one primary research publication (Ghahhari et al. 2022). The main findings of this project are in the phase of manuscript preparation. We are confident that the significance of the findings will lead to high impact factor publication, that will reach a broad scientific audience. Once published, special attention will be brought to the dissemination through presentations at conferences, communication via social media, media outlets and ETH networks.
With respect to understanding the heterogeneity within the primary tumour and metastasis,
we analysed the barcode-clone composition in the primary tumour and metastases, using DNA/RNA extraction followed by PCR amplification. The samples were submitted for DNA and RNA sequencing. Subsequently, the analysis of the sequencing results has been carried out and we were able to identify barcode structure in primary tumour and metastases, offering an outlook on cellular dynamics during the metastatic process. Analysis of gene expression in different tissues of metastasis allowed us to provide link between the gene expression pattern and the potential of a tumour cell to metastasize. The genes of interest are tested functionally by gain and loss-of function assays.
Regarding the role of microenvironment in the metastatic progression, we applied an unbiased approach of sequencing niche cells from primary tumour and metastasis. To this end we were able to isolate the cells in the immediate surroundings of cancer cells, and the molecular profiling by 10X single-cell RNA-sequencing enabled the identification of broad populations of cells in the environment. We were able to identify populations of cells enriched in the metastases. These findings are essential for the understanding of how the cancer cells may be regulated by other cells in their niche, to drive metastasis.
The work on this project has resulted in one review article on this topic (Sznurkowska and Aceto 2021) and one primary research publication (Ghahhari et al. 2022). The main findings of this project are in the phase of manuscript preparation. We are confident that the significance of the findings will lead to high impact factor publication, that will reach a broad scientific audience. Once published, special attention will be brought to the dissemination through presentations at conferences, communication via social media, media outlets and ETH networks.
The field of cancer metastasis has been focused on the analysis of mutations or epigenetic alterations affecting the primary tumour cells. However, the clonal analysis of different populations of metastasising cancer cells has been scarce. This research involved a combination of cutting edge techniques – DNA barcoding that enables the study of thousands of clones in parallel, combined with molecular profiling and functional analysis of the role of implicated genes.
This analysis contributed to the field of cancer metastasis by providing a molecular and cellular model of the process.
As outlined above, the societal implications of answering the questions asked in this project are essential.
Overall, the knowledge gained thanks to this project will aid the design of new methods for early diagnosis and the monitoring of patients with metastasis, as well as the development of new strategies that target or prevent metastasis. Given the absolute necessity of developing those methods, it is likely that once the results will be published, they will have a wide impact and inspire further promising clinical work.
This analysis contributed to the field of cancer metastasis by providing a molecular and cellular model of the process.
As outlined above, the societal implications of answering the questions asked in this project are essential.
Overall, the knowledge gained thanks to this project will aid the design of new methods for early diagnosis and the monitoring of patients with metastasis, as well as the development of new strategies that target or prevent metastasis. Given the absolute necessity of developing those methods, it is likely that once the results will be published, they will have a wide impact and inspire further promising clinical work.