Inflammatory diseases are common, debilitating and affect the well-being of millions of people worldwide. Almost any part of the body can become inflamed, resulting in pain and suffering. For example, Crohn's disease, or colitis, is caused by intestinal inflammation and is manifested by pain, diarrhea and weight loss. Asthma is caused by the inflammation of lung airways and impacts breathing. Atherosclerosis, which involves blood vessel inflammation, leads to heart attacks, strokes, blindness and poor circulation. Because of the wide impact of these diseases, there is an urgent need to control and treat inflammation. The Conway lab was the first to determine that a protein called CD248, plays an important role in controlling inflammatory disorders. When inflammation is present, CD248 is made in high amounts by both stromal and perivascular cells, which reside in all tissues of the body. By generating mice that lack CD248 or a part of the molecule, Dr. Conway's group tested the hypothesis that CD248 might make inflammation worse. Indeed, CD248 ""knockout"" mice develop less severe joint inflammation (arthritis). This finding — that CD248 is involved in inflammation — was very significant, as it points to CD248 as a potential drug target for anti-inflammatory drugs. Dr. Yanet Valdez is now taking this research one step further to determine exactly how CD248 increases inflammation. She is using various biochemical methods to determine which inflammatory diseases are affected by CD248 and what parts of the CD248 protein influence inflammation. The studies will help her figure out how to better turn off the pro-inflammatory effects of CD248 and devise therapies to reduce inflammation severity.
Research Pillar: Biomedical
Synthetic lethal interactions with cancer CIN genes: investigating potential therapeutic targets
Genetic instability is a hallmark of cancer cells. One type of genomic instability seen in >80 percent of solid tumours is called Chromosome Instability (CIN). Cancer cells can contain mutations in CIN genes, and these genes make the cells more genetically susceptible to mutation than normal cells. Cells with CIN have large aberrations in chromosome structure and/or number, including the gain or loss of chromosomes and chromosomal breaks and fusions. This creates a vulnerability that can potentially be exploited therapeutically to selectively kill these cells. However, because of their nature, mutated CIN genes are difficult to identify directly.
Dr. Melanie Bailey is using RNA interference (RNAi) technology to specifically identify CIN genes of interest. She will be collaborating with Dr. Jason Moffat's laboratory at the University of Toronto to search for genes that pair with known CIN genes and are mutated in spontaneous and rare hereditary cancers. She will also be collaborating with Dr. Phil Hieter's lab at the University of British Columbia (UBC) to test a network of gene pairs previously identified by computer analysis of a public genetic database (BIOGRID) in a human cell line using RNAi.
By combining these approaches, Dr. Bailey expects to identify novel gene pairs that will be further studied using various cell biology and biochemical methods. She hopes that her research will help to better understand how CIN works and that it will provide insight into finding novel ways of killing CIN-mutated cells. Finally, Dr. Bailey will identify inhibitors of the CIN genes through collaboration with Dr. Michel Roberge, whose lab at UBC regularly screens chemical compounds for their inhibitory potential. These inhibitors may represent a viable cancer therapy for the future, as they would be specific for killing CIN-mutated cells.
Investigation of breast cancer genome heterogeneity in predictive models of drug action
A common method of testing new cancer drugs is to use human breast tumour cells that have been transplanted into mice. How this transplantation process and drug treatments affect the grafted cells is not known. In particular, we need to know if certain types of mutation within the tumour may survive the process of engraftment better than others, resulting in a transplanted tumour that has a different composition and different properties from the original human tumour. Dr. Peter Eirew's aim is to study in detail how the “landscape” of different gene mutations in the tumor evolves when tumour cells undergo transplantation and subsequent treatment with anti-cancer drugs. Dr. Eirew will sequence the entire DNA and RNA (a measure of the active genes in a cell) of breast cancer patients' tumours before and after transplantation into mice to see how the frequency of each mutation changes over time. Dr. Samuel Aparicio's group has already read the entire DNA sequence of human breast cancer — both the original tumour and a recurrence in a different part of the patient's body nine years later — and showed that the type and frequency of the mutations changed over time. In the second part of the study, he will sequence these human tumour cells before and after the drug treatment to determine the types of mutations that survive. This will set the stage for a follow-on clinical study to determine how closely the drug response of these human cells predict how tumours in patients respond to the same drugs. This study will be the first attempt to define how grafted breast cancer cells behave in mice and how this behaviour is affected by the choice of grafting methods and treatment with existing drugs. This information will be used to improve the methods that are currently used to test potential new cancer drugs, with the ultimate aim of bringing new breast cancer treatments into routine use more quickly than in the past. Knowing the types and combination of mutations that are present in a tumour and how this combination changes during treatment will be the key to developing new and more effective drugs. The study may also identify new mutations in breast tumours, which have the potential to answer more specific questions about how these cancers arise, progress and become resistant to treatment.
Proteolytic signatures and networks in breast cancer metastases
Breast cancer is the second most common form of cancer. A crucial event in the development of the disease is when cells start to leave the breast tumour, enter the bloodstream and start to form a new tumour in other organs, such as the lung and bone. This process, called metastasis, dramatically reduces the patient's chances of disease recovery. Hence, in depth understanding of this process is key to successful development of novel anti-cancer drugs to provide effective treatment for cancer patients. Although the genetic changes that cause cancer to develop and metastasize are being studied, there are other molecular events that contribute to cancer. The post-translational modification of proteins — which refers to the changes that occur after the proteins are built — can dramatically alter the protein function, putting it in a different place or switching the activity on or off. One way to modify a protein is to cleave a part of it off, exposing a new protein """"tail.” Identification of the actual modification patterns in different disease situations will presumably allow for a much more precise disease diagnosis. Knowing the protein differences between metastases, which are surprisingly different from the tumours they originate from, will help to identify the fundamental causes and provide great insight into the cellular processes affected during cancer. Dr. Philipp Lange's research involves the identification of protein """"tails"""" in different cancer tumours and metastases in order to identify differences between the two. He will also introduce a new protein into the tumours that can mediate the cleavage reactions in a controlled manner, which will enable him to deduce how the individual protein components of tumours were originally connected. As a final step in his research, he will investigate the key protein modification patterns (or """"signatures"""") found in the mouse model and see if this signature exists in patient tumour samples taken from the Tumour Tissue Repository at the BC Cancer Agency. The impact of Dr. Lange's work will be twofold. First, the protein modification signatures he identifies will be used to develop a powerful new method to support earlier breast cancer diagnosis and determination of patient prognosis. Second, the identified key network modulators serve as potential drug targets for the development and testing of new breast cancer therapeutics.
Investigating biochemical signatures of radiation resistance in human breast and prostate cancers via single cell Raman spectroscopy
Radiation therapy is the recommended treatment for about one-third of all cancer patients, including those with breast and prostate cancer. One factor limiting the use of radiation therapy is the considerable difference in radiation response between patients. There are currently no proven biochemical or imaging methods to assess a cancer patient's radiation response during an extended radiation therapy treatment. There is a need to develop customized radiation treatments to accommodate the variations in radiation response from individual patients; however, implementing such personalized treatments requires a better understanding of the fundamental biochemical responses of human tumour cells to ionizing radiation. Dr. Quinn Matthews is investigating the use of Raman spectroscopy as a way to monitor radiation responses in cancer patients undergoing radiotherapy. Raman spectroscopy is a non-invasive technique that shows great promise for the biochemical analysis of cellular radiation responses, as it can provide sensitive molecular information from biological samples, such as human cells or tissues. Recent laboratory studies have shown that single-cell Raman spectroscopy techniques applied to irradiated cells can detect radiation-induced changes in certain proteins, lipids and nucleic acids within human prostate, breast and lung tumour cells. These results suggest that certain types of radiation-induced biochemical changes measured with Raman spectroscopy are correlated with tumour-cell resistance to radiation treatment. The goal of Dr. Matthews' research project is to apply the proven capabilities of Raman spectroscopy to investigate the biochemical radiation response of a variety of human breast and prostate cancers, irradiated both in vitro (in the lab) and in vivo (in the organism). The results of this research will lead to increased effectiveness of radiation therapy by facilitating the development of personalized adaptive treatments designed to account for individual radiation response.
Mitigation of hippocampal dysfunction and cognitive deficits in early-symptomatic YAC128 transgenic mice for Huntington’s disease
Huntington's disease is a devastating neurodegenerative disorder affecting between three and 10 individuals per 100,000 in the Western world. It is caused by a mutation in the huntingtin gene, which results in the accumulation of mutated huntingtin protein in the brain and the eventual degeneration of certain types of brain cells. The disease is primarily characterized by the onset of motor deficits; this develops when the striatum region deep within the brain begins to degenerate. However, Huntington’s disease patients commonly show cognitive impairments decades before the onset of the motor symptoms. The hippocampus is a brain region known to be involved both in cognitive (i.e. learning and memory) and emotional (i.e. depression) processes.
Dr. Joana Gil-Mohapel is investigating whether the hippocampus is involved in the early cognitive impairments in Huntington’s disease. She is working with a mouse model of Huntington’s disease, which closely mimics the human condition. These mice demonstrate profound structural and functional deficits in this region; significantly, as seen in Huntington’s disease patients, these deficits can be detected when the animals are still in an early-symptomatic stage, before the onset of motor symptoms. Therefore, the goal of the present research is to gain a better understanding of how this structure is affected in this mouse model.
Dr. Gil-Mohapel will investigate whether relevant cellular pathways are altered in this brain region and whether therapies aimed at promoting hippocampal function can reverse these deficits and be of therapeutic value for Huntington’s disease. She hopes her research will help elucidate novel targets for the mitigation of the cognitive deficits characteristic of early-stage Huntington’s disease patients.
Functional characterization of MLL2 mutations in follicular and diffuse large B-cell lymphomas
Lymphomas are cancers of the immune system. Canadian cancer statistics estimated around 8,100 newly diagnosed cases and 3,300 deaths from lymphoma in 2009. Lymphomas develop as the result of errors, or mutations, in the proteins that regulate the rate of cell division. These types of mutations are found in many different cancer types; however, certain mutations are found only in a specific cancer type. When the same mutation is found in several patients of a specific cancer type, it is likely to be a cancer-causing or cancer-driving mutation. The aim of Dr. Maria Mendez-Lago’s research is to investigate the impact of mutations found in the gene MLL2 on the formation and progression of lymphomas. Her research team discovered mutations in MLL2 by using next-generation sequencing of 127 non-Hodgkin lymphoma cases. Based on the pattern and distribution of the mutations, they believe MLL2 is a new tumour suppressor that might be acting through de-regulation of gene expression. Next-generation sequencing has allowed Dr. Mendez-Lago’s team to do whole genome, exome, and transcription sequencing using limited amounts of DNA from cancer tissues – an approach that was not possible only four years ago. They are applying this technology to different applications, such as the targeted sequencing approach used to detect mutations in MLL2. MLL2 has only recently been linked to cancer, so there is a great need to study the gene in further detail to understand how mutations in this gene promote cancer. To explore the impact of these mutations, Dr. Mendez-Lago’s team will culture and study all lines similar to the cancer cells from patients. Their findings will likely determine new candidates for designing drugs to treat cancers.
Investigating anti-arrhythmic inhibition of voltage-gated sodium channels with unnatural amino acids and fluorescence spectroscopy
Cardiac arrhythmias are on the rise in our aging population. They are electrical disturbances in the heart that can cause a wide variety of potentially life-threatening conditions, including an increased chance of stroke or, in the case of heart failure, sudden death. Anti-arrhythmic drugs that target a particular type of protein called an “ion channel” are useful in converting these irregular heart rhythms back to a normal beating. Unfortunately, many available anti-arrhythmic drugs have serious side effects. The basic action mechanisms of anti-arrhythmic drugs are not understood, and the chemical characteristics of good/safe anti-arrhythmic drugs are not known. This makes it difficult to engineer the next generation of life-saving cardiac drugs. Dr. Stephan Pless is aiming to fill crucial gaps in our understanding of how anti-arrhythmic drugs regulate heart function. By combining cutting-edge chemical methods with computer modeling, he has already made significant progress in defining the essential characteristics of what makes a “good” anti-arrhythmic drug. His next goal is even more important, as it aims to define the precise nature of the heart receptor through which anti-arrhythmic drugs modulate electric excitability. For this purpose, he will employ novel artificial amino acids to delineate the precise location of the receptor and will use novel fluorescent probes to give us insights into the atomic-level movements of the receptor during drug binding. All of the technologies used here have been tested in other relevant systems, but never for this application; therefore, it places Dr. Pless in a position to make a substantial contribution to the cardiovascular health of Canadians.
Generation of a humanized mouse xenotransplant model of myelodysplastic syndrome
Myelodysplastic syndromes (MDS) are diseases of the blood and bone marrow. MDS originate when a stem cell, from which all other blood cells originate, becomes mutated and then overgrows and crowds out other cells. This results in reduced numbers of red cells (anemia), white cells (leukopenia) and platelets (thrombocytopenia) circulating in the blood. As the disease progresses, bone marrow may completely fail to produce normal cells, and the myelodysplastic stem cell may develop into cancer, Acute myeloid leukemia (AML). The exact molecular causes for MDS are unknown; however, a common feature of MDS is chromosomal abnormality, the loss of the long arm (q) of the chromosome 5 being one of the most common in a subtype of MDS called 5q- syndrome. This lost region of 5q likely harbors several important genes, which may prevent MDS.
Dr. Joanna Wegrzyn Woltosz's research project will decipher the molecular mechanism of the disease and identify targets of a new drug (lenalidomide) currently used in MDS treatment. She is studying two important factors that are located on the 5q arm and are involved in the development of MDS (1) the RPS14 gene, which is thought to be responsible for the anemia seen in MDS patients, and (2) microRNAs, whose loss allows the abnormal MDS stem cells to survive and grow more than the other bone marrow cells. Since lenalidomide reverses symptoms resulting from loss of the microRNAs, she will also study whether lenalidomide increases the expression of these microRNAs. Currently, the only treatment for MDS is high-dose chemotherapy with stem cell transplantation, which is risky and challenging for patients to endure.
The information Dr. Wegrzyn Woltosz expects to obtain from this study will not only help to better understand the molecular mechanism underlying MDS, but will suggest novel steps towards the development of better therapies that will improve treatment and quality of life and increase survival for MDS patients.
Identification and characterization of leukemia stem cells in T-cell acute lymphoblastic leukemia (T-ALL)
The traditional view of cancer is that tumours are composed of identical cells, and thus the goal of treatment is to kill every one of those cancer cells in the body. In a tumour, it is estimated that a very small fraction of cells (perhaps 1 in 10,000) are ""cancer stem cells"", which are the cells that have the capacity to self-renew or to create progeny that carry the same properties as the parent cell. A new cancer treatment theory hypothesizes that to treat cancer, the only cells that need to be killed off are these cancer stem cells, and once they are gone the rest of the tumour should regress on its own. The challenge becomes to first identify the cancer stem cells and then design a drug that would specifically kill those cancer stem cells only. Dr. Vincenzo Giambra's lab has recently shown that cancer stem cells exist in a particular type of blood cancer called T-cell acute lymphoblastic leukemia (T-ALL). Although T-ALL is not a common form of cancer, it is unique in that more than 50 per cent of cases carry mutations that inappropriately activate a gene called Notch1, which plays an important role in normal stem cell maintenance. Dr. Giambra's research objectives are to identify how cancer stem cells are able to evade the immune system and thrive in T-ALL, and to design a drug that specifically kills those cancer stem cells. He will be isolating cancer stem cells from a unique mouse model that has Notch1-induced T-ALL, using specific molecules on the surface of cancer stem cells. He will also compare leukemias generated from mice of different ages to see if they express different genes, with the goal of using this information to design new drugs that may help to cure more patients with leukemia. These studies will allow Dr. Giambra to define the genetic programs and pathways that are responsible for conferring self-renewal upon the leukemia stem cells; they will also provide rationale for the design of new therapies that specifically target the stem cells. In focusing his efforts toward killing only the cancer stem cells, Dr. Giambra expects these therapies will be more effective for achieving a cure and less toxic to the patient. Finally, he anticipates that some of the genetic programs and pathways he will identify will be critical for self-renewal of Notch T-ALL stem cells and may be important for self-renewal of all cancer stem cells in general. Thus, these results may prove useful to investigators studying other cancers as well.