Mechanistic understanding of the lifecycle of a circulating hybrid cell.

Project Summary Metastatic disease accounts for >90% of cancer-related deaths worldwide, yet this phase of tumor progression is the least biologically understood. The consequence of this lack of knowledge is that we do not have the appropriate therapeutic arsenal to defeat metastatic cancer. New revelations for colorectal cancer point to shed

neoplastic cells into peripheral blood even from early stage tumors, suggesting this is why some early stage tumors recur despite seemingly successful treatment. However, whether all early stage primary tumors shed neoplastic cells, or if only subsets of more aggressive neoplastic cells garner ability to disseminate is not known.

This highlights the critical gap in knowledge of the mechanisms underlying neoplastic cell dissemination leading to distant disease. Identifying the key features within the lifecycle of a disseminated tumor cell will unravel this important step in tumor progression with potential to influence management of cancer care. Our study leverages

newly developed state-of-the-art phenotypic analyses of key attributes of a recently discovered neoplastic hybrid cell in primary tumors and in peripheral blood, termed circulating hybrid cells (CHCs), supported by cutting-edge computational analyses. Interestingly, CHCs harbor tumor-initiating properties implying that they have high

potential as effectors of metastatic tumor seeding. We will detail cells poised to disseminate from the primary tumor into circulation and seed metastatic sites combining protein, multi-omic analyses and functional behavioral analyses. A focus on a stage II and late stage colorectal cancer cohorts support analyses across the disease

axis, with an emphasis on stage II CRC patients with undetected micrometastases at the time of diagnoses. Evaluation of the lifecycle of the hybrid cell from primary tumor to dissemination will provide biologic insight into the metastatic process with great potential to impact the management and care of patients with cancer.