The goal is to bring a safe and effective therapy to adult patients with critical narrowing of the upper windpipe (trachea) and lower voicebox (larynx). Our intent is to implement all of the necessary steps for a successful new stem/progenitor cell-derived airway transplant for later stage clinical trials and/or commercialization within 4 years. Our team builds on first-in-human surgical successes with stem cell-based tissue engineered airway implants in compassionate use cases in adults and children. To this end, we will perform the necessary preclinical studies to support a successful IND application within 2 years, followed by a Phase I trial in 10 patients with 1 year of follow-up. We propose to use stem/progenitor cells from the patients themselves to treat an extraordinarily difficult to manage health problem, namely large airway stenosis. This causes severe airway obstruction, which severely limits quality of life, exercise tolerance, communication, and social and employment opportunities. Occasionally, the stenosis may also be life threatening. It occurs in approximately 200 individuals in California each year. Treatment costs for these patients are very high, and the personal and societal investments are substantially higher, although outcomes are consistently poor. The endpoint desired is normal airway and lung function and an improved quality of life. Our team aims to eliminate the need for repeated surgical interventions and/or the use of stents (metal or plastic tube implants), which are not necessarily successful, yet presently the standard of care for such patients.
In 2008/2010, we used stem cell-based, engineered tracheal implants to successfully save a young woman's and a child's life. Both are very well at 5 and 3 years post-implantation. These first-in-human studies emphasize that our goal is realistic, but also highlighted the gaps in our knowledge. Specifically, there is a need for preclinical studies to address questions of safety and long-term maintenance of airway, as well as to determine the fate of the implanted cells; secondly, if supported by these preclinical safety studies, there is a need for a formal clinical trial in patients of our candidate airway implant. Stem/progenitor cell-derived airway transplants that use the patients' own cells have the clinical advantage of not requiring anti-rejection medications. Our experience, to date, indicates such medication is not needed and this finding represents a scientific and clinical breakthrough in organ transplantation. While medical benefit was demonstrated in these two preliminary patients, there is substantial work to be done before such transplants can be considered routine for patients. We address this challenge with our team approach and emphasize the synergism that occurs when linking team members from California and a partner institution, with expertise in a variety of scientific and medical disciplines to address this critical need.
The citizens of California have generously invested in stem cell research and a return on their investment will include breakthroughs in medical treatments for diseases where there are currently limited options. Tissue-engineered stem/progenitor cell-derived airway transplantation is a leading example of translational research in regenerative medicine that can be used for a host of diseases. Through this team effort scientists and physicians will lead the early promise of airway transplantation to clinical trials in California and beyond.
This research team proposes to use tissue-engineered airway scaffolds with stem and progenitor cells to cure an extraordinarily difficult to manage and life-threatening health problem. Severe airway obstruction occurs in approximately 200 adults in California each year. The morbidity associated with this disease is very high, and it can be fatal for some. The knowledge gained from the tissue engineering and preclinical studies proposed will provide a new technology that can be applied to these and other disorders in California. We foresee that our stem cell-derived airway transplant could also be extended to treat an important subpopulation of children with severe subglottic and tracheal stenosis, malacia, or agenesis that have proven refractory to standard surgical interventions, and adult patients with debilitating laryngeal scarring. A further exciting possibility is that stem cell-derived airway transplants or bioengineered stents could also be applied to treat an important subpopulation of adults with severe chronic obstructive pulmonary disease (COPD). Given that the prevalence rate of COPD for California citizens greater than 65 years of age approaches 10%, if even 0.1% of COPD patients in California were candidates, specifically those with associated tracheobronchomalacia, then greater than 3,000 patients might benefit from this treatment. The methods and technology developed from this project can also be used as the basis for other similar health needs including esophageal, bladder, and bowel replacements for disorders where present treatments are very limited and impair quality of life.
- This project focuses on a developmental candidate that is an airway construct, composed of a customized tissue engineered biologic scaffold, populated with cells from the recipient (mesenchymal and epithelial). The construct is a decellularized donor section of trachea, based on implants used in humans in compassionate use cases (adults and children). The studies, to date, have focused on optimized techniques for collecting and characterizing cells, tracheal decellularization techniques, and tracheal recellularization strategies. A summary of achievements includes the following: (1) Cells: comparable marker expression and tri-lineage differentiation potential shown, and no differences in phenotypic or functional properties with transduction to express reporter genes for imaging confirmed; (2) Decellularization: decellularization standard operating procedures (SOP) identified, decellularized trachea shown to meet all success criteria, and biomechanical testing optimized; (3) Recellularization: compared bioreactor designs and identified a recellularization SOP, and optimized conditions for external and intraluminal seeding. In Year 1 we have made significant progress with new and innovative approaches to meet our milestones and goals.
Critical to the long term success of the CIRM iPSC Initiative of generating and ensuring the availability of high quality disease-specific human IPSC lines is the establishment and successful operation of a biorepository with proven methods for quality control, safe storage and capabilities for worldwide distribution of high quality, highly-characterized iPSCs. Specifically the biorepository will be responsible for receipt, expansion, quality characterization, safe storage and distribution of human pluripotent stem cells generated by the CIRM stem cell initiative. This biobanking resource will ensure the availability of the highest quality hiPSC resources for researchers to use in disease modeling, target discovery and drug discovery and development for prevalent, genetically complex diseases.
The generation of induced pluripotent stem cells (iPSCs) from patients and subsequently, the ability to differentiate these iPSCs into disease-relevant cell types holds great promise in facilitating the “disease-in-a-dish” approach for studying our understanding of the pathological mechanisms of human disease. iPSCs have already proven to be a useful model for several monogenic diseases such as Parkinson’s, Fragile X Syndrome, Schizophrenia, Spinal Muscular Atrophy, and inherited metabolic diseases such as 1-antitrypsin deficiency, familial hypercholesterolemia, and glycogen storage disease. In addition, the differentiated cells obtained from iPSCs represent a renewable, disease-relevant cell model for high-throughput drug screening and toxicology/safety assessment which will ultimately lead to the successful development of new therapeutic agents. iPSCs also hold great hope for advancing the use of live cells as therapies for correcting the physiological manifestations caused by disease or injury.
- The California Institute for Regenerative Medicine (CIRM) Human Pluripotent Stem Cell Biorepository is operated by the Coriell Institute for Medical Research and is a critical component of the CIRM Human Stem Cell Initiative. The overall goal of this initiative is to generate, for world-wide use by non-profit and for-profit entities, high quality, disease-specific induced pluripotent stem cells (iPSCs). These cells are derived from existing tissues such as blood or skin, and are genetically manipulated in the laboratory to change into cells that resemble embryonic stem cells. iPSCs can be grown indefinitely in the Petri dish and have the remarkable capability to be converted into most of the major cell types in the body including neurons, heart cells, and liver cells. This ability makes iPSCs an exceptional resource for disease modeling as well as for drug screening. The expectation is that these cells will be a major benefit to the process for understanding prevalent, genetically complex diseases and in developing innovative therapeutics.
- The Coriell CIRM iPSC Biorepository, located at the Buck Institute for Research on Aging in Novato, CA, is funded through a competitive grant award to Coriell from CIRM and is managed by Mr. Matt Self under the supervision of the Program Director, Dr. Steven Madore, Director of Molecular Biology at Coriell. The Biorepository will receive biospecimens consisting of peripheral blood mononuclear cells (PBMCs) and skin biopsies obtained from donors recruited by seven Tissue Collector grant awardees. These biospecimens will serve as the starting material for iPSC derivation by Cellular Dynamics, Inc (CDI). Under a contractual agreement with Coriell, CDI will expand each iPSC line to generate sufficient aliquots of high quality cryopreserved cells for distribution via the Coriell on-line catalogue. Aliquots of frozen cell lines and iPSCs will be stored in liquid nitrogen vapor in storage units at the Buck Institute with back-up aliquots stored in a safe off-site location.
- Renovation and construction of the Biorepository began at the Buck Institute in late January. The Biorepository Manger was hired March 1 and after installation of cryogenic storage vessels and alarm validation, the first biospecimens were received on April 30, 2014. Additionally, Coriell has developed a Clinical Information Management System (CIMS) for storing all clinical and demographic data associated with enrolled subjects. Tissue Collectors utilize CIMS via a web interface to upload and edit the subject demographic and clinical information that will ultimately be made available, along with the iPSCs, via Coriell’s on-line catalogue
- As of November 1 specimens representing a total of 725 unique individuals have been received at the Biorepository. These samples include PBMCs obtained from 550 unique individuals, skin biopsies from 72 unique individuals, and 103 primary dermal fibroblast cultures previously prepared in the laboratories of the CIRM Tissue Collectors. A total of 280 biospecimen samples have been delivered to CDI for the purpose of iPSC derivation. The Biorepository is anticipating delivery of the first batches of iPSCs for distribution in early 2015. These lines, along with the associated clinical data, will become available to scientists via the on-line Coriell catalogue. The CIRM Coriell iPSC Biorepository will ensure safe long-term storage and distribution of high quality iPSCs.
Induced pluripotent stem cells (iPSCs) have the potential to differentiate to nearly any cells of the body, thereby providing a new paradigm for studying normal and aberrant biological networks in nearly all stages of development. Donor-specific iPSCs and differentiated cells made from them can be used for basic and applied research, for developing better disease models, and for regenerative medicine involving novel cell therapies and tissue engineering platforms. When iPSCs are derived from a disease-carrying donor; the iPSC-derived differentiated cells may show the same disease phenotype as the donor, producing a very valuable cell type as a disease model. To facilitate wider access to large numbers of iPSCs in order to develop cures for polygenic diseases, we will use a an episomal reprogramming system to produce 3 well-characterized iPSC lines from each of 3,000 selected donors. These donors may express traits related to Alzheimer’s disease, autism spectrum disorders, autoimmune diseases, cardiovascular diseases, cerebral palsy, diabetes, or respiratory diseases. The footprint-free iPSCs will be derived from donor peripheral blood or skin biopsies. iPSCs made by this method have been thoroughly tested, routinely grown at large scale, and differentiated to produce cardiomyocytes, neurons, hepatocytes, and endothelial cells. The 9,000 iPSC lines developed in this proposal will be made widely available to stem cell researchers studying these often intractable diseases.
Induced pluripotent stem cells (iPSCs) offer great promise to the large number of Californians suffering from often intractable polygenic diseases such as Alzheimer’s disease, autism spectrum disorders, autoimmune and cardiovascular diseases, diabetes, and respiratory disease. iPSCs can be generated from numerous adult tissues, including blood or skin, in 4–5 weeks and then differentiated to almost any desired terminal cell type. When iPSCs are derived from a disease-carrying donor, the iPSC-derived differentiated cells may show the same disease phenotype as the donor. In these cases, the cells will be useful for understanding disease biology and for screening drug candidates, and California researchers will benefit from access to a large, genetically diverse iPSC bank. The goal of this project is to reprogram 3,000 tissue samples from patients who have been diagnosed with various complex diseases and from healthy controls. These tissue samples will be used to generate fully characterized, high-quality iPSC lines that will be banked and made readily available to researchers for basic and clinical research. These efforts will ultimately lead to better medicines and/or cellular therapies to treat afflicted Californians. As iPSC research progresses to commercial development and clinical applications, more and more California patients will benefit and a substantial number of new jobs will be created in the state.
- First year progress on grant ID1-06557, " Generation and Characterization of High-Quality, Footprint-Free Human Induced Pluripotent Stem Cell (iPSC) Lines From 3000 Donors to Investigate Multigenic Disease" has met all agreed-upon milestones. In particular, Cellular Dynamics International (CDI) has taken lease to approximately 5000 square feet of lab space at the Buck Institute for Research on Aging in Novato, CA. The majority of this space is located within the new CIRM-funded Stem Cell Research Building at the Buck Institute and was extensively reconfigured to meet the specific needs of this grant. All equipment, including tissue culture safety cabinets and incubators, liquid-handling robotics, and QC instrumentation have been installed and qualified. A total of 16 scientists have been hired and trained (13 in Production and 3 in Quality) and more than 20 Standard Operating Procedures (SOPs) have been developed and approved specifically for this project. These SOPs serve to govern the daily activities of the Production and Quality staff and help ensure consistency and quality throughout the iPSC derivation and characterization process. In addition, a Laboratory Information Management System (LIMS) had to be developed to handle the large amount of data generated by this project and to track all samples from start to finish. The first and most important phase of this LIMS project has been completed; additional functionalities will likely be added to the LIMS during the next year, but completion of phase 1 will allow us to enter full production mode on schedule in the first quarter of year 2. Procedures for the shipping, infectious disease testing, and processing of donor samples were successfully implemented with the seven Tissue Collectors. To date, over 700 samples have been received from these Tissue Collectors and derivation of the first 50 patient-derived iPSC lines has been completed on schedule. These cells have been banked in the Coriell BioRepository, also located at the Buck Institute. The first Distribution Banks will be available for commercial release during year 2.
Idiopathic Pulmonary Fibrosis (IPF) is a progressive and generally fatal disease that causes scarring of the lungs and therefore an inability to breathe. Its true prevalence is unknown, as it may go unrecognized for many years, but it is generally thought to affect more than 200,000 people in the USA and is five times more common than cystic fibrosis or amyotrophic lateral sclerosis. The mortality from the disease is very high with about two-thirds of patients dying within five years of diagnosis. The cause and reasons for progression of disease are unknown, but are likely complex and multifactorial, involving genetic predisposition and environmental exposures. A small percentage of cases run in families.
Our lack of therapies and understanding of IPF may in large part be due to the fact that there are no good models of the disease. Therefore, the potential development of a model of IPF from iPSC derived from IPF patients would be a major advance for the field and has the potential for drug and pathway discovery that would make a huge impact on patients’ lives. [REDACTED] has one of the largest IPF clinics on the west coast and has a Clinical Trials Group and a registry for IPF. Here we propose to recruit IPF patients from the IPF clinic to donate a blood sample for iPSC derivation. We will also track their demographic and medical data. These iPSCs will then be used for disease modeling of IPF followed by high throughput drug discovery testing to identify therapies for IPF.
Idiopathic pulmonary fibrosis (IPF) is a devastating fatal lung disease that usually occurs in the 7th decade of life. The disease causes scarring of the lungs that make it impossible to breath. The prevalence of IPF is on the rise and expected to double in the next 20 years as the U.S. population continues to age. The prevalence worldwide in the population that is greater than 65 years of age is predicted to be around 125 IPF cases per 100,000 people. California, the most populous state, is also the state with the largest number of people 65 years of age and over (3.6 million people in the year 2000) and therefore the prevalence of IPF in the USA is highest in California with over 5,000 cases.
By virtue of the severity of this disease, patients will almost always progress to end stage lung failure and the only therapy available is a lung transplant. In addition to the suffering and disability that IPF causes, the costs associated with caring for patients with IPF, including lung transplant costs, are extremely large. For example a single lung transplant costs roughly $400,000 and this doesn’t include all the follow up care needed post-transplant or any complications.
Improving our understanding of and identifying therapies for IPF will therefore have a major impact on patients in California with IPF. Firstly, it will reduce much pain and suffering and secondly it will reduce costs and free up donor lungs, that are in short supply, for other end stage lung disease patients.
- We have now collected 115 blood samples from patients with Idiopathic Pulmonary Fibrosis for reprogramming to induced pluripotent stem cells, This is ahead of our 1 year target of collecting 100 samples.
- This quarter we collected blood samples from 33 patients with IPF in order to generate induced pluripotent stem cell lines to study IPF.
The primary goal is to bring a safe and effective therapy to children with severe large airway disease. Our intent is to implement all of the necessary steps for a successful new stem/progenitor cell-derived airway transplant for clinical trials in children within 4 years. Our team builds on first-in-human surgical success with a stem cell-based tissue engineered airway implant in a compassionate care case in a young adult and in a child. To this end, we will perform the necessary preclinical studies to support a successful FDA application within 4 years. We propose to use stem/progenitor cells from the patient to treat an extraordinarily difficult-to-manage health problem in children, namely large airway disease. In children this leads to collapse of tracheal cartilage causing severe airway obstruction that is life-threatening. It occurs in approximately 200 California children each year and the morbidity and mortality associated with this disease is very high. Approximately 25% of these young patients die before their first birthday. Treatment costs for these children are very high, and the familial and societal investments are substantially higher, although outcomes are consistently poor. The endpoint desired is normal airway and lung function and a normal quality of life. Our team aims to eliminate the need for repeated surgical interventions which are not necessarily successful, presently the standard of care for children with large airway obstruction. Bioengineered airway transplants that use the cells of the patients could be used in humans of all age groups and would not require lifelong, harmful anti-rejection medications.
In 2008 and 2010, a stem cell based, tissue engineered tracheal implant was successfully used by our team to save a young woman's and a child's life, respectively. These first-in-human studies emphasize that our goal is realistic and paves the way for clinical trials in children after carefully designed safety studies are completed for preclinical testing. Stem/progenitor cell-derived airway transplants that use the patient's cells have the clinical advantage of not requiring anti-rejection medications long-term. Our experience, to date, indicates such medication is not needed and this finding represents a scientific and clinical breakthrough in organ transplantation. While clear medical benefit was demonstrated in these proof-of-principle, compassionate care human cases, there is substantial work that must be done before considering such transplants for pediatric patients, and on a large scale, for adults. We address this challenge with our team approach and emphasize the synergism resulting from linking team members with expertise in a variety of scientific and medical disciplines to address this critical need. This new therapeutic approach could offer a tremendous benefit to children and patients in other age groups in the State of California that are in desperate need of new treatment options.
The citizens of California have generously invested in stem cell research and a return on their investment will include breakthroughs in medical treatments for diseases where there are currently limited options. Stem/progenitor cell-derived airway transplantation is a leading example of translational research in regenerative medicine that can be used for a host of diseases. Through this team effort scientists and physicians will lead the early promise of airway transplantation to clinical trials in California and beyond.
The research team proposes to use stem and progenitor cells to cure an extraordinarily difficult to manage and life-threatening health problem in children. Severe airway obstruction occurs in approximately 200 California children each year. The morbidity and mortality associated with this disease is very high; approximately 25% of patients will die before their first birthday. The knowledge gained from the preclinical studies proposed will provide a new technology that can be applied to other disorders in California populations. We foresee that our stem cell-derived airway transplant could also be applied to treat an important subpopulation of adults with severe chronic obstructive pulmonary disease (COPD) and the large number of children and adults with severe subglottic stenoses that have proven refractory to standard surgical interventions, and patients with debilitating laryngeal scarring. Given that the prevalence rate of COPD for California citizens greater than 65 years of age approaches 10%, if even 0.1% of COPD patients in California were candidates, specifically those with associated tracheobronchomalacia, then greater than 3,000 patients might benefit from this treatment. The methods and technology developed from this project can also be used as the basis for other similar health needs including esophageal, bladder, and bowel replacements for disorders where present treatments are very limited and impair quality of life.
- We have built a highly experienced, multidisciplinary clinical, managerial, and scientific team to deliver a new stem cell based treatment for children with advanced airway disorders. There are no satisfactory treatments for severe collapse of the windpipe in children. Conventional surgery leads many children requiring repeated hospital admissions and can have serious complications, whilst the use of internal supports (stents) can cause infections, bleeding and coughing. We have performed one adult and one child airway replacement operations using implants based on the patient's own stem cells. The windpipe scaffolds were derived from transplant donors, with all the donor cells removed but all the good biological properties retained. At three and one half and two years respectively, both patients are doing very well: the adult is working and the child at school. From the lessons learned by these ‘first-in-human’ experiences, we have been able to propose research work leading to, and including, the world's first clinical trial of an organ replacement based on stem cells, here the windpipe in needy children. With our first-in-human experiences, we believe this project has a very high chance of successful delivery of a landmark clinical trial in California within the four-year period of funding requested.
Chronic lung disease is an enormous societal and medical problem in California and the nation as a whole, representing the third most likely cause of death. Treatment costs were $389.2 billion in 2011 and are expected to reach $832.9 billion in 2021 according to the Milken Institute. Chronic lung diseases cover a spectrum of disorders that include pulmonary fibrosis, a disease that makes it difficult to breathe due to the accumulation of scar tissue in the lung, and chronic obstructive pulmonary disease (COPD), a disease that makes breathing difficult due to loss of critical structures that allow oxygen to enter the blood. According to Breathe California, COPD is the 4th leading cause of death in the United States and 1.6 million Californians are diagnosed with COPD. Treatment options vary by disease but are particularly ineffective for patients with COPD and fibrotic lung diseases. One fibrotic lung disease termed idiopathic pulmonary fibrosis (IPF) can only be treated by lung transplantation and this option is limited to those who meet specific age and health criteria. Without transplantation the majority of IPF patients die within three years of initial diagnosis.
Our research team being recruited to California is led by an international expert in lung stem cell biology and includes a leading physician in pulmonary fibrosis research and clinical management. Goals of research outlined in this proposal are to understand how lungs are damaged by diseases and to develop new treatment options to help prevent, arrest, or repair damage leading to
improved patient health. Specifically, we will show how cells that line airspaces of the lung generate new cells that function to protect the lung from injury and facilitate gas exchange during breathing. Through this work it will be possible to determine how lung disease is caused and this will lead to new therapies that will prevent either initiation or progression of lung disease.
Lung disease has an enormous societal impact. For the period from 1990-2008 chronic lower respiratory diseases were the third most likely cause of death in the US, accounting for approximately 6% of deaths and an annual rate of approximately 0.1% of the total population (NHLBI report, 2010). Lung diseases can be caused by either genetic and/or environmental factors, and are
compounded by age-related declines in lung function. Poor air quality in and around major California cities are well documented and have been conservatively estimated to account for 10,000 hospital visits per year (RAND Corporation report, 2010). Ozone and particulate airborne pollutants are a significant concern due to chronic effects on lung tissue remodeling in otherwise
healthy individuals. They also trigger exacerbations in patients with existing lung disease leading to more serious illness and death. Interventions can include imposing strict air quality standards and improving therapies for patients either with or who are at risk of developing lung disease. Pulmonary fibrosis in particular represents a major unmet medical need in California and lung transplant is the only effective therapy at present. Accordingly, defining mechanisms of lung fibrosis and developing cures for otherwise intractable lung diseases has the potential to significantly benefit the population of California.
This CIRM Research Leadership Award application will develop a transformative program aimed at applying new discoveries in basic mechanisms of lung disease towards development of new interventions to help patients. This will be accomplished by integrating the applicant’s expertise in lung stem cell biology and regenerative medicine with basic and translational research
strengths at the destination institution. Previous work has shown that signaling interactions between epithelial progenitor cells and their associated stromal microenvironment are critical for normal development and tissue homeostasis in adulthood. These interactions are dysregulated in many lung diseases including fibrotic lung diseases, chronic obstructive pulmonary disease and asthma. This proposal will focus on fibrotic lung diseases in particular due to the poor prognosis that results from lack of effective therapies. Through identifying mediators that regulate epithelial progenitor-stromal interactions in the normal adult lung, and how changes in their activity contribute to disease, we will gain new insights into disease mechanisms and therapies. We expect that discoveries will be broadly applicable to many lung diseases and will significantly impact Californians through
novel drug discoveries that improve the health and quality of life of patients with early onset or established lung disease.
- Chronic lung disease is an enormous societal and medical problem in California and the nation as a whole, representing the third most likely cause of death with treatment costs of $389.2 billion in 2011 and expected to reach $832.9 billion in 2021 according to the Milken Institute. Chronic lung diseases cover a spectrum of disorders that include pulmonary fibrosis, a disease that makes it difficult to breathe due to the accumulation of scar tissue in the lung, and chronic obstructive pulmonary disease (COPD), a disease that makes breathing difficult due to loss of critical structures that allow oxygen to enter the blood. According to Breathe California, COPD is the 4th leading cause of death in the United States and 1.6 million Californians are diagnosed with COPD. Treatment options vary by disease but are particularly ineffective for patients with COPD and fibrotic lung diseases. One fibrotic lung disease termed idiopathic pulmonary fibrosis (IPF) can only be treated by lung transplantation and this option is limited to those who meet specific age and health criteria. Without transplantation the majority of IPF patients die within three years of initial diagnosis. Our research program has relocated from Duke University Medical Center to Cedars-Sinai Medical Center with the goal of translating a basic understanding of disease mechanisms to improved patient care. We have developed new tools to understand cell types and regulatory mechanisms that participate in lung repair and disease in mouse models. These new mouse models allow us to investigate ways that lung cells interact to repair damage in an intact animal model, and have allowed us to develop new ways of reconstructing regulatory cell interactions in a culture environment. Parallel culture models for analysis of human lung cell types have allowed us to investigate the critical roles for cell-cell interactions in the regulation of epithelial repair and aberrant tissue remodeling. Our long-term goal is to determine how lung disease is caused and use this information to develop new therapies that will prevent either initiation or progression of lung disease.
- Our research program seeks to identify reparative cells of the lung that contribute to normal maintenance and repaired after injury, determine how they are regulated at the molecular level, and to determine how and why these cells are disregulated in lungs of patients with chronic lung diseases such as idiopathic pulmonary fibrosis (IPF) and chronic obstructive pulmonary disease (COPD). Our long-term goal is to determine how lung disease is caused and use this information to develop new therapies that will prevent either initiation or progression of lung disease. We have made progress in studies using mouse models to investigate lung repair mechanisms and also with human samples to understand how lung tissue stem cells change in patients with lung disease. In animal studies we have defined cells that migrate within the lung to repair damage caused by severe H1N1 influenza virus infection. We have developed methods to grow lung tissue in a dish and are using this technology to screen for drugs that promote lung repair and/or inhibit scaring of lung tissue. Our work with patient samples has allowed us to identify molecular signatures of normal lung cell types that line airspaces of the lung and molecular changes to these cells seen in IPF. We have made significant progress in the development “lung in a dish” models for human cells and have established methods for the generation of lung cell types from patient-specific pluripotent cells (a type of stem cell that has the potential to generate all cells of the body). Continuation of this work will provide new model systems and a more comprehensive understanding of molecular changes to lung cells that accompany disease. This information will allow us to define new targets for drug development and opportunities to help patients with intractable lung diseases.
Lung cancer is the most deadly cancer worldwide and accounts for more deaths than prostate cancer, breast cancer and colon cancer combined. Non small cell lung cancer (NSCLC) accounts for about 85% of all lung cancers. The current 5-year survival rate for all stages of NSCLC is only 15%. Although early stage lung cancer has a much better survival rate. Current therapeutic strategies of chemotherapy, radiation therapy and trials with new targeted therapies have only demonstrated, at best, extension in survival by a few months. Clearly, a novel approach is required to develop new therapies for this devastating disease and to detect the disease at an early stage. Cancer stem cells have been identified as the initial cell in the formation of carcinomas. Chemotherapy, radiation and even targeted therapies are all designed to eliminate dividing cells. However, cancer stem cells “hide out” in the quiescent phase of growth. This provides an explanation as to why our cancer therapies may produce an initial response but are often unsuccessful in curing patients. Lung cancer develops through a series of step wise changes that result in the progression of pre-malignant lesions to invasive lung cancer. The mechanisms of how lung cancer develops are not known and if we can prevent the formation of pre-malignant lesions, we will likely be able to prevent lung cancer. We have discovered a subpopulation of stem cells that circulates in the blood and is essential for normal lung repair. Blocking these cells from entering the lung results in a pre-malignant condition in the lungs. We have also identified a subpopulation of stem cells in the lung that is responsible for generating pre-malignant lung cancer lesions. We hypothesize that the interaction between the stem cells in the blood and the stem cells in the lung are critical to prevent lung cancer. We plan to use cutting edge technologies to characterize these different stem cell populations in the lung, and determine how they form pre-malignant lung cancer lesions. We also plan to use preclinical models to try to prevent lung cancer by giving additional stem cells derived from the blood as a therapy. Lastly, we plan to determine whether levels of stem cells in the blood in patients may be used as a blood test to measure the chance of recurrence of lung cancer after therapy. The long term goals of our work are to develop a screening test for lung cancer stem cells that can predict which patients are at high risk for developing lung cancer in order to diagnose lung cancer at an early stage, and to potentially develop a new stem cell based therapy for preventing and treating lung cancer.
According to the Center for Health Statistics, California Department of Health Services, 13,427 people died of lung cancer in the state of California in 2005. This is more than the deaths attributed to breast, prostate and colon cancers combined. The devastating effects of this disease on the citizens of California and the health care costs involved are enormous. Most cases of lung cancer occur in smokers, but non smokers, people exposed to second hand smoke and ex-smokers are also at risk. In addition, of special concern to California residents, is that exposure to air pollution is associated with an increased risk of lung cancer. Current therapeutic strategies for lung cancer are in general only able to prolong survival by a few months, especially for late stage disease. One reason for this may be that the cancer initiating stem cell is resistant to these therapies. Understanding the stem cell populations involved in repair of the lung and how these cells may give rise to lung cancer is important for potentially generating new therapeutic targets for lung cancer. We propose to study the stem cell populations of the lung that are crucial for normal airway repair and characterize the putative cancer initiating stem cell in the lung. We have also found stem cells in the blood that are critical for normal airway repair and we plan to test their role in the prevention of premalignant lung cancer lesions. We also plan to test whether levels of these stem cells in the blood may be used as a biomarker of lung cancer. Ultimately, the ability to perform a screening test to detect lung cancer at an early stage, and the development of new therapies for lung cancer will be of major benefit to the citizens of California.
- We identified a putative tumor-initiating stem/progenitor cell that goes rise to smoking-associated non small cell lung cancer (NSCLC). We examined 399 NSCLC samples for this tumor-initiating stem/progenitor cell and found that the presence of this cell in the tumor gave rise to a significantly worse prognosis and was associated with metastatic disease. This stem/progenitor cell is known to be important for repair of the airway and is present in precancerous lesions. We believe that this cell undergoes aberrant repair after smoking injury, which leads to lung cancer. We are currently trying to identify the genetic and epigenetic mechanisms involved in this aberrant repair as a means to identify a novel therapy to prevent the development of lung cancer. The presence of these stem/progenitor cells may also be used as a biomarker of poor prognostic NSCLC even in early stage disease.
- We have identified markers on these stem/progenitor tumor-initiating cells and identified sub-populations of these cells. We are now determining the stem cell capabilities of each of these sub-populations. We are using a model of the development of lung cancer to determine if giving a stem/progenitor cell sub-population for repair can prevent NSCLC from developing.
- We examined the blood of patients diagnosed with a lung nodule for circulating epithelial stem/progenitor cells. We found that the presence of these cells in the blood of patients predicted the presence of a subtype of NSCLC as compared to a benign lung nodule. We are currently obtaining many more blood samples from patients to further determine whether circulating epithelial stem/progenitor cells could be used as a biomarker of early NSCLC.
- We have found a stem cell that is important for lung repair after injury that is located in a protected niche in the airway. After repeated injury, for example in smokers, these stem cells persist in an abnormal location on the surface of the airway and replicate and form precancerous areas in the lung. The presence of these stem cells in lung cancer tumors was associated with a poor prognosis with an increased chance of relapse and metastasis.This was especially true in current and former smokers. We therefore believe we have found a putative stem cell that is a tumor initiating cell for lung cancer. We developed a method to isolate these lung stem cells and to profile these cells and developed in vitro and in vivo models to assess their stem cell properties. Finally, we examined human blood samples to assess levels of surrogate markers of these stem cells to assess whether we could use this as a biomarker to predict the presence or absence of lung cancer in patients with a lung nodule.
- We found a stem cell that is important for lung repair after injury that we believe may form precancerous areas in the lung. We are characterizing these stem cells and identifying pathways involved in normal repair and aberrant repair that leads to lung cancer. We are also isolating this stem cell population and other cell populations from the airway and inducing genetic changes to determine the tumor initiating cell/s for lung cancer. We are also examining the effect the environment may have on the regulation of genes in these stem cells, in precancerous areas and in lung cancers. Finally, we are examining human blood samples to assess levels of surrogate markers of these stem cells to assess whether we could use this as a biomarker to predict the presence or absence of lung cancer in patients with a lung nodule.
- During this period of funding we discovered a method to reproducibly recover stem cells from human airways and grow them in a dish into mature airway cells. We also discovered the role that certain metabolic cell processes play in regulating the repair after airway injury. We believe that an inability to shut off these processes leads to abnormal repair and lung cancer and are actively investigating this. We are also determining whether the stem cells we isolate from the airways are the stem cells for lung cancer and how they might give rise to lung cancer.
- In the last year of funding we identified a novel mechanism that tightly controls airway stem cell proliferation for repair after injury. We found that perturbing this pathway results in precancerous lesions that can ultimately lead to lung cancer. Correcting the abnormalities in this pathway that are seen in smokers could allow the development of targeted chemoprevention strategies to prevent the development of precancerous lesions and therefore lung cancer in at risk populations. We also continued our work on trying to identify a cell of origin for squamous lung cancer and identifying the critical drive mutations that are required for squamous lung cancer to develop.
- During this reporting period we discovered and published on how reactive oxygen species drive proliferation of airway basal stem cells. We found that this pathway is critical for homeostasis of the airway epithelium and perturbing this pathway results in precancerous lesions. Interestingly, these precancerous lesions are able to resolve over time, which is similar to the situation in smokers who develop precancerous lesions that almost always resolve. We now have a model to study the driver mutations that take precancerous lesions to invasive squamous lung cancer and with this model we can start to identify novel therapies to prevent the development of precancerous lesions and/or progression of precancerous lesions. We also developed a model of precancerous lesions in a dish which allows us to screen for compounds that promote or resolve these premalignant lesions. Our overall goal is to use these models to develop a targeted chemoprevention strategy for squamous lung cancer.