Development of a New Human Model of Lung Squamous Cell Carcinoma Progression
Lead Research Organisation:
University of Manchester
Department Name: Cancer Research UK Manchester Institute
Abstract
Lung squamous cell carcinoma (LUSC) is a devastating disease which accounts for approximately 5% of all cancer mortality in the UK, is strongly associated with smoking and lacks targeted therapies. Detecting early stage LUSC provides the best chance of therapeutic success as these patients are eligible for curative surgery (60% 5-year overall survival). However, 75% of LUSC patients are diagnosed with advanced disease and are treated with chemotherapy and, more recently, immunotherapy but with limited therapeutic benefit (6% 5-year overall survival).
These dismal figures highlight the need to improve LUSC medicine. This can only be achieved by developing more innovative and ambitious research models that reflect the genetic complexity of LUSC and recapitulate progression from premalignant stages to invasive cancer. Unfortunately, the mechanisms driving this progression remain unclear and this hinders efforts to develop these much-needed patient-relevant models.
The genomes of LUSC are complex and differ among patients, but a closer look shows that some genetic alterations occur in most patients. Additionally, low-frequency genetic alterations often target the same cellular processes and arise in the tumour following a recurrent temporal order that gives rise to a series of 'genetic stages'. These commonalities can be exploited to design more relevant models of LUSC. However, carrying out this modelling effort in mice would require large cohorts of animals due to the number of genes involved and the genetic diversity found in patients. We cancer biologists must try to avoid this cost in mouse lives and find alternative strategies to replace animals in LUSC research in as many translational applications as possible.
Human basal cells (HBCs) are the cell-of-origin of LUSC, can be easily cultured in-vitro and are more likely to reflect better the human cell biology. Therefore, HBCs are an attractive and versatile system to investigate this disease and replace mice in translational LUSC studies. In this work, we intend to engineer HBCs to reproduce the genetic stages and the diversity found in LUSC patients. In following this strategy, I aim to build a model of LUSC progression that best recapitulates the spectrum of premalignant and invasive LUSC stages to replace mouse models.
The first objective of this project is to genetically-engineer HBCs to reproduce the series of genetic stages observed in patients. The selection of alterations will be based on their high frequency and known role in important LUSC pathways. The second objective will be to analyse the cellular changes in each genetic stage including invasiveness, cell proliferation and changes to tissue architecture. The last objective will be to investigate changes in gene expression, immuno-modulatory factors, and intra-tumour heterogeneity.
On completing the validation stage, we aim to have acquired a comprehensive dataset providing the most complete knowledge of the biological changes driving LUSC progression as well as a tractable LUSC model to expand our preclinical research opportunities.
The most innovative aspects of this modelling strategy are a) the use of human cells instead of mouse models, b) the recapitulation of genetic stages that aims to incorporate tumour evolution into cancer modelling strategies and c) the emphasis on premalignant stages. These features will broaden our capabilities to investigate specific areas of LUSC biology in a stage-dependent manner that cannot be undertaken using existing preclinical models, while avoiding the important differences in lung biology between mouse and human. After completing the validation of the model, we intend to focus on the biology of premalignant stages, new cancer vulnerabilities and stage-dependent changes in the immune microenvironment. These research areas will accelerate the development of new early detection methods, novel therapeutic modalities, and the improvement of existing ones.
These dismal figures highlight the need to improve LUSC medicine. This can only be achieved by developing more innovative and ambitious research models that reflect the genetic complexity of LUSC and recapitulate progression from premalignant stages to invasive cancer. Unfortunately, the mechanisms driving this progression remain unclear and this hinders efforts to develop these much-needed patient-relevant models.
The genomes of LUSC are complex and differ among patients, but a closer look shows that some genetic alterations occur in most patients. Additionally, low-frequency genetic alterations often target the same cellular processes and arise in the tumour following a recurrent temporal order that gives rise to a series of 'genetic stages'. These commonalities can be exploited to design more relevant models of LUSC. However, carrying out this modelling effort in mice would require large cohorts of animals due to the number of genes involved and the genetic diversity found in patients. We cancer biologists must try to avoid this cost in mouse lives and find alternative strategies to replace animals in LUSC research in as many translational applications as possible.
Human basal cells (HBCs) are the cell-of-origin of LUSC, can be easily cultured in-vitro and are more likely to reflect better the human cell biology. Therefore, HBCs are an attractive and versatile system to investigate this disease and replace mice in translational LUSC studies. In this work, we intend to engineer HBCs to reproduce the genetic stages and the diversity found in LUSC patients. In following this strategy, I aim to build a model of LUSC progression that best recapitulates the spectrum of premalignant and invasive LUSC stages to replace mouse models.
The first objective of this project is to genetically-engineer HBCs to reproduce the series of genetic stages observed in patients. The selection of alterations will be based on their high frequency and known role in important LUSC pathways. The second objective will be to analyse the cellular changes in each genetic stage including invasiveness, cell proliferation and changes to tissue architecture. The last objective will be to investigate changes in gene expression, immuno-modulatory factors, and intra-tumour heterogeneity.
On completing the validation stage, we aim to have acquired a comprehensive dataset providing the most complete knowledge of the biological changes driving LUSC progression as well as a tractable LUSC model to expand our preclinical research opportunities.
The most innovative aspects of this modelling strategy are a) the use of human cells instead of mouse models, b) the recapitulation of genetic stages that aims to incorporate tumour evolution into cancer modelling strategies and c) the emphasis on premalignant stages. These features will broaden our capabilities to investigate specific areas of LUSC biology in a stage-dependent manner that cannot be undertaken using existing preclinical models, while avoiding the important differences in lung biology between mouse and human. After completing the validation of the model, we intend to focus on the biology of premalignant stages, new cancer vulnerabilities and stage-dependent changes in the immune microenvironment. These research areas will accelerate the development of new early detection methods, novel therapeutic modalities, and the improvement of existing ones.
Technical Summary
Lung squamous cell carcinoma (LUSC) arises from the accumulation of genomic alterations in basal cells, the resident stem cells in the bronchial epithelium. Regardless of a complex pattern of driver genes and extensive heterogeneity, LUSC tumours present important commonalities such as frequent inactivation of TP53 and CDKN2A, genetic alterations recurrently targeting important pathways and repetitive temporal patterns in which genetic alterations occur during tumour evolution. This new perspective into LUSC genetics can be exploited to build more accurate LUSC models that reflect patient heterogeneity and the developmental stages of the disease. Using cultured human basal cells (HBCs) constitutes an excellent system to develop these comprehensive models of LUSC and replace large cohorts of mouse models in a wide range of basic and translational research areas. In this project, we will recapitulate the evolutionary history of LUSC in HBCs in order to build a new human model of LUSC progression, thereby providing an alternative in-vitro model of this disease.
To develop this model, we will generate genetically-engineered HBCs harbouring cumulative genetic alterations in a sequential manner, mimicking the evolutionary stages of LUSC. The selection of genetic alterations will be based on high frequency of mutations in patients, alterations targeting pathways recurrently altered in LUSC and drivers of intra-tumour heterogeneity. To validate the model, we will analyse the cumulative role of the genetic alterations in driving the landmarks of LUSC progression, including invasiveness, epithelial alterations, proliferation, gene-expression changes, genome instability and secretion of immuno-modulatory factors. This model will enable us to replace mouse models to investigate clinically relevant aspects of LUSC biology such as precancerous stages and cooperation of somatic alterations, and will reflect better the human biology and heterogeneity of LUSC.
To develop this model, we will generate genetically-engineered HBCs harbouring cumulative genetic alterations in a sequential manner, mimicking the evolutionary stages of LUSC. The selection of genetic alterations will be based on high frequency of mutations in patients, alterations targeting pathways recurrently altered in LUSC and drivers of intra-tumour heterogeneity. To validate the model, we will analyse the cumulative role of the genetic alterations in driving the landmarks of LUSC progression, including invasiveness, epithelial alterations, proliferation, gene-expression changes, genome instability and secretion of immuno-modulatory factors. This model will enable us to replace mouse models to investigate clinically relevant aspects of LUSC biology such as precancerous stages and cooperation of somatic alterations, and will reflect better the human biology and heterogeneity of LUSC.
