Hilal Bashir, PhD, Postdoctoral Fellow Weill Cornell Medicine Area of Research: Colorectal Cancer Chronic stress is increasingly recognized as a significant factor exacerbating various chronic illnesses, including cancer and autoimmune diseases, yet the mechanisms involved remain poorly understood. Stress-induced alterations in gut microbiota composition and function, alongside bidirectional communication via the gut-brain axis, are emerging as key players in modulating the immune response. However, it remains unclear how chronic stress affects immune response to cancer or cancer immunotherapies. The gut microbiome is a major driver of immune system development and immune response to infection and cancer. By utilizing a novel mouse model of chronic stress coupled with colorectal cancer, Dr. Bashir’s preliminary studies revealed a significant increase in tumor growth in a gut microbiome and B cell-dependent manner. Dr. Bashir found that chronic stress altered the gut microbiome and impaired B cell response to tumors. He plans to investigate how stress dysregulates B cell response and how the gut microbiome could be manipulated to mitigate adverse effects of chronic stress on B cells and anti-tumor immunotherapies. His studies will utilize novel mouse models and human colorectal tumor tissues. By leveraging his innovative chronic stress model and expertise in gnotobiotic animal studies and immune cell profiling, this work will uncover chronic stress-induced specific changes in the gut microbiome and intratumor bacteria that impair anti-tumor B cell response. Dr. Bashir’s findings will have the potential to unravel therapeutic strategies to target the gut microbiome to revert the negative impact of chronic stress and improve the outcomes of cancer immunotherapies. Projects and Grants Defining the stress-gut microbiome interplay in anti-tumor B cell response Weill Cornell Medicine | Colorectal Cancer | 2024 | Melody Y. Zeng, PhD
