There is a critical need for new therapeutic approaches to treat advanced stage rectal cancer, which has increased incidence in younger people and poor prognosis. Working with a multidisciplinary team, Dr. Aguilera is leading a randomized clinical trial that combines an anti-CD40 agonist immunotherapy with radiation and chemotherapy for locally advanced rectal cancer. The drug aims to activate the protein CD40 on dendritic cells which plays a critical role in generating T-cell immunity. As part of the study, Dr. Aguilera is investigating the factors that influence a patient's immune response to this combination treatment with the goal of optimizing therapy for difficult gastrointestinal cancers. If the proposed treatment is successful, it could become a new therapeutic standard that lowers the risk of metastasis, improves survival, shortens the treatment course and potentially avoids the need for surgery.

Dietary interventions such as caloric restriction (CR) and ketogenic diet (KD) are reported to limit tumor growth partially by modulating stem cell function. The intestine functions as the main organ of nutrient absorption and, due to rapid tissue renewal via intestinal stem cells (ISCs), is sensitive to shifts in the body’s metabolic state before and after eating. Both CR and KD conditions dramatically enhance the activity of an enzyme in ISCs known as HMGCS2. This enzyme controls ketogenesis, the conversion of fatty acids into ketone bodies as a means of producing energy when glucose is unavailable. Dr. Chi aims to dissect the role of ketone body metabolites in modulating intestinal stem cell function and tumor growth. With a better understanding of how intestinal stem cells adapt to diverse diets, he hopes to identify new strategies or dietary interventions that prevent and reduce the growth of cancers in the intestinal tract. Dr. Chi received his PhD from the University of California, Los Angeles and his BS from Zhejiang University.

Cancer cells form complex interactions with the various normal cells in their environment, including immune cells, fibroblasts, and blood vessels. These interactions are essential for cancer cells to grow, evade immune surveillance, and become metastatic or resistant to certain therapies.  Spatial transcriptomics refers to a method of visualizing the distribution of RNA molecules in a tissue sample, allowing us to assign specific cell types to their locations. Dr. Chu [William Raveis Charitable Fund Quantitative Biology Fellow] aims to develop a statistical framework to infer how different cell types interact with each other based on spatial transcriptomics data. He will use this statistical framework to study cell-cell interactions in both colorectal cancer and inflammatory bowel disease, a risk factor for colorectal cancer.

Dr. Chu will develop a hierarchical Bayesian statistical model to deconvolve the spatial transcriptomic data and then resolve cell type-specific information. Based on the deconvolved spatial data, he will then deploy a Bayesian spatial model to infer the interaction between various cell types.

Dr. Cote is exploring embryonic development to better understand how cells cooperate and build complex tissues. Since cancer cells often erroneously redeploy developmental programs and behaviors, her research into how neighboring cells align will yield insights into how cancerous cells metastasize and invade other tissues. Dr. Cote is combining tissue-specific genetic manipulations and laser cell ablations with live imaging during Caenorhabditis elegans digestive tract development to reveal how intracellular organization in one cell type can influence the alignment, polarity, and function of cells in the neighboring tissues.

Dr. Donaldson [Robert Black Fellow] is investigating the difference between a healthy mucosal surface and a tumor-promoting surface in the gut. Bacteria in the gut associate intimately with the surface of the intestine, where they exert a constant influence on the immune system throughout an organism’s life. Studies indicate that certain gut bacteria in cancer patients reside in the mucus of the intestinal surface and may promote (or potentially inhibit) the growth of tumors, perhaps through effects on the immune system. Uncovering specific “molecular conversations” that maintain a healthy community of mucosal bacteria may lead to novel therapies to prevent the origin of colorectal cancers in addition to treating existing tumors.

Regulation of gene transcription is a major mechanism cells use to modify the levels of certain proteins in response to their environment. A specific class of genes called immediate-early genes (IEGs) responds rapidly to external stimuli to adjust downstream gene transcription programs before any new proteins are synthesized. Abnormal expression of IEGs has been implicated in multiple types of cancers, as well as in neurological syndromes like addiction. Despite extensive study, the regulation of IEGs remains poorly understood. Dr. Gu’s work focuses on revealing the molecular mechanisms of IEG expression in cells and establishing model systems to study the physiological and disease-related outcomes caused by misregulation of this process. Dr. Gu received her PhD from MIT and her BSc from Peking University.

DNA stores the information for making all the proteins in an organism. Transfer RNA (tRNA) plays a key role in building the proteins from this blueprint. tRNA molecules recognize specific sequences (three-letter codons) and deliver the corresponding amino acids needed to make a protein. Dr. Hsu recently found that certain starvation conditions can cause some tRNAs to be modulated in colorectal cancer cells. He will study the changes in tRNA levels that occur in response to cellular starvation states. He aims to shed light on how cancer cells adapt to starvation, which potentially can lead to new therapeutic approaches to target metabolic dependencies in cancer.

Dr. Hueschen studies the motility of Apicomplexan parasites, which cause malaria, foodborne illness (toxoplasmosis) and infections in immunocompromised cancer patients. These parasites move through the human body using a mechanism called "gliding" to migrate over host cells and through the surrounding extracellular matrix. Dr. Hueschen's goal is to understand how molecules inside the parasite are organized, coordinated and regulated to produce forces that direct movement. This research has the potential to aid in the development of therapies to prevent opportunistic infections.

In addition to acute illness, viruses can cause cancers. While our understanding of cellular immunity against viruses that have DNA-based genomes is robust, we know less about how cells protect themselves against RNA-based viruses such as hepatitis C, a leading cause of liver cancer. Because many cellular defenses against viruses are known to be shared between mammals and bacteria, Dr. Mendoza [HHMI Fellow] is looking for new cellular defenses against RNA viruses in bacteria and will investigate how these defenses work. The resulting discovery of anti-viral defenses will broaden our understanding of how cells protect themselves against RNA viruses, which will improve our capacity to support patients' immune systems when infected with cancer-causing RNA viruses. Dr. Mendoza received their PhD from the University of California, San Francisco, and their BS from the University of Miami.

Human cells compact their vast genomes into the small confines of the nucleus by wrapping their DNA into a highly complex structure called chromatin. Packaging DNA into chromatin, however, affects all nucleic acid-transacting machines (e.g., transcription factors) that need to access the genomic information stored in the DNA. NuRD is a large multi-subunit protein complex that plays a major role in making chromatin either accessible or inaccessible. Dysregulation of NuRD and aberrant targeting of the complex can result in the emergence of several types of cancers, including breast, liver, lung, blood, and prostate cancers. Dr. Osorio Valeriano’s [Philip O'Bryan Montgomery, Jr., MD, Fellow] work will reveal mechanistic aspects of NuRD-mediated chromatin regulation and pave the way for the development of novel therapeutic approaches that target cancers more effectively. Dr. Osorio Valeriano received his PhD from Philipps University and his MSc and BSc from the National Autonomous University of Mexico.