Promising new treatments for cancers of the bladder and kidney have been developed, but, as with many cancer therapies, tumors eventually develop resistance. Research has shown that cancer cells resist treatment in part via epigenetic changes—those that do not affect the DNA sequence itself but turn important genes on or off, allowing cancers to survive under therapeutic stress. Dr. Baca is using novel techniques to study the epigenomes of cancer cells from blood samples. His goal is to understand how changes in the epigenomes of bladder and kidney cancers lead to treatment resistance. This knowledge will enable the design of better treatments and drug combinations that will benefit patients with metastatic bladder or kidney cancers.

Abnormal interactions between our immune system and our gut microbes can lead to inflammation that drives colon and gastric cancer growth. Dr. Brian [HHMI Fellow] is investigating how the immune system recognizes and responds to these microbes, and how these interactions contribute to abnormal inflammation that can fuel cancer growth. Microbiota-immune interactions have been generally studied in the context of "clean" laboratory mice, but these models do not fully capture human immunology and the complex interplay between host cells and foreign microbes. To overcome this, Dr. Brian plans to study these interactions in "dirty" mice, colonized by a diverse community of microbes as well as pathogens. He will then use laboratory mice with more defined microbial communities to test how recognition of specific microbes by the immune system is regulated and how disruptions to this regulation contributes to inflammation. Dr. Brian received his PhD from the University of Minnesota, Twin Cities and his BS from the University of California, Santa Barbara.

Hepatocellular carcinoma (HCC) is the most common liver cancer and has one of the highest cancer-related mortality rates. Conventional cancer immunotherapies, which largely focus on enhancing T cell activity, are unfortunately effective in only a small minority of HCC patients. Though dendritic cells (DCs) are essential for T cell activation, their potential as an immunotherapeutic target remains poorly understood. Dr. Cao [Bakewell Foundation Fellow] is investigating how a unique, hyperactivated state of DCs can be harnessed to enhance anti-tumor immunity in a genetically engineered mouse model of HCC. Her work aims to uncover how hyperactivated DC responses generate stronger and longer-lasting protection against HCC and hopefully other cancers that are poorly responsive to conventional therapies. Dr. Cao received her MD, PhD from Albert Einstein College of Medicine, Bronx and her BS from Cornell University, Ithaca. 

Proteins found on the surface of cells are key agents in cancer progression, as they play a role in cell signaling and metastasis. Targeted protein degradation has emerged as a therapeutic strategy to modulate what are considered “undruggable” proteins. Specifically, lysosomal-targeting protein degradation (LTPD), which uses the cancer cell’s own degradation machinery to break down proteins, has demonstrated therapeutic potential. However, the proteins targeted for LTPD have been limited to a few well-studied membrane and extracellular proteins, leaving much still unknown about the breadth of proteins that can be targeted for degradation and the features of a target protein that determine LTPD efficacy. Dr. Floyd [HHMI Fellow] aims to systematically characterize the features of cell surface proteins that drive the efficacy of LTPD with the goal of identifying new targets for blood cancer treatment. Dr. Floyd received his PhD from University of Texas at Austin, Austin and his BS from California Polytechnic State University, San Luis Obispo.

Dr. Freije [Berger Foundation Fellow] is studying how the genetic diversity of hepatitis B virus (HBV) is shaped by its need to replicate and interact with specific host genes. Current antiviral therapeutics for HBV merely suppress infection and do not cure disease; as a result, patients with chronic HBV infection are at risk of developing liver cancer. Dr. Freije plans to uncover essential genomic regions that HBV needs to survive and persist, as well as those that counteract host genes that function to restrict these activities. This approach could provide insight into the progression of disease and has the potential to identify new antiviral therapeutics and ultimately reduce the incidence of HBV-associated liver cancer.

Drug therapies that selectively target proteins that drive the growth of tumor cells are rapidly becoming the standard of care for many cancers. However, tumors are often able to evade inhibition by targeted anti-cancer drugs by activating other proteins, leading to drug resistance. Dr. Gier [HHMI Fellow] is developing a new therapeutic approach that repurposes existing drugs to release highly toxic cargoes, known as payloads, that aggregate in drug-resistant cancer cells and kill them. As a general platform, it is applicable to a wide range of solid and liquid cancers. Dr. Gier received his PhD from University of Pennsylvania, Philadelphia and his BA from Swarthmore College, Swarthmore. 

Mitochondria harbor independent genetic material known as mitochondrial DNA (mtDNA). This compact, circular molecule encodes proteins essential for the assembly of the mitochondrial electron transport chain to generate energy in form of ATP. Like nuclear DNA, mtDNA is susceptible to damage and mutations. One of the most common disease-causing aberrations of mtDNA is termed “common deletion.” This aberration disrupts mitochondrial function, resulting in neuromuscular diseases and potentially certain cancers, including colorectal cancer. Due to a lack of tools to modify the mitochondrial genome, researchers currently do not understand the mechanisms behind common deletion. Dr. Kavlashvili [Timmerman Traverse Fellow] aims to investigate by using cutting-edge molecular biology tools to edit and visualize mtDNA genomes. She will then be poised to unravel impacts of this deletion on various tissues, in order to ultimately mitigate its pathological impact. Dr. Kavlashvili received her PhD from Vanderbilt University, Nashville and her BS from University of Iowa, Iowa City.

Ammonia, a waste product of cellular activity, is cleared from the body by the liver and kidneys through a process known as the urea cycle. During the urea cycle, ammonia is converted to urea, and arginine (an amino acid) is generated. When liver cells become cancerous, the urea cycle pathway stops functioning and cancer cells must import arginine from outside the cell. When cancer cells are prevented from importing arginine (via removal of arginine from the diet or genetic removal of the transporter), tumors do not grow, suggesting that arginine is critical for cells. However, the function of arginine in the cell is unclear. Using mass spectrometry and mathematical modeling, Dr. Lesner will identify the fate of arginine as it is metabolized by liver cancer cells in mouse models, and investigate how this is altered by various genetic mutations. Additionally, he will examine how restricting arginine from the diet genetically alters the liver and tumor cells. By understanding how disruption of this metabolic pathway influences liver cancer growth in the context of specific cancer drivers, Dr. Lesner aims to inform new therapeutic strategies. Dr. Lesner received his PhD from The University of Texas Southwestern Medical Center, Dallas and his BA from the University of Wooster, Wooster, Ohio.

Dr. Li’s research aims to uncover a missing link between repeated DNA sequences, genomic instability, and viruses. While abnormal expansion of “repeats” has been found at unstable genomic regions, known as fragile sites, that are implicated in cancer growth, the mechanisms and consequences of this genomic instability remain poorly understood. Dr. Li recently discovered a cluster of Epstein Barr Virus (EBV)-like repeat sequences in the genome that breaks when bound by abnormally high levels of EBV antigens. These findings illustrate how a chromosome can be broken in long-term EBV infection, which can threaten genome stability and trigger cancer development. Dr. Li aims to leverage this discovery to advance our understanding of how broken repeats threaten genome integrity for clinical screening of individuals susceptible to EBV-associated diseases, and for the prevention and treatment of disease in these individuals. This research could also lead to the discovery of other virus-like repeats and the potential biological function of these virus-like repeats in our genome.  

While immunotherapies such as anti-PD-1 therapy have provided an important treatment option for bladder cancer, the majority of patients do not respond to these regimens. This may reflect the distinct activation requirements of other immune T-cells besides CD8+ T-cells. In recent work, Dr. Oh and colleagues have identified cytotoxic (cancer cell-killing) CD4+ T-cells in human bladder cancer that are associated with immunotherapy responses. However, the regulation of cytotoxic CD4+ T-cells and how these mechanisms compare with CD8+ T-cells is not understood. Dr. Oh proposes to identify and validate surface receptors that enhance or inhibit the activity of cytotoxic CD4+ T cells in human bladder cancer, and the tumor antigens that are recognized specifically by these cells. He will also compare which of these regulatory mechanisms are unique to cytotoxic CD4+ T-cells relative to their CD8+ T-cell counterparts from the same patients. This work has the potential to increase both the proportion of bladder cancer patients who respond to immunotherapy as well as the quality of their response.