PROJECT SUMMARY
While primary, early-stage breast cancer is curable, metastatic breast cancer remains a clinically significant
problem. Recent analyses of clinical samples have shown that the increased infiltration of sympathetic and
sensory nerve fibers into the mammary tumors, a phenomenon known as tumor innervation, is highly correlated
with metastatic potential of breast cancer. Despite recent interests in understanding breast tumor innervation,
there still exists a critical gap in fundamental knowledge in the molecular and cellular mechanisms of breast
tumor innervation. The goal of this project is to address this gap in knowledge by studying metabolic regulations
of breast tumor innervation and subsequent effects on metastasis.
A wealth of literature suggests that metabolic dysregulation could in fact be linked to tumor innervation and
heightened metastatic potential. For instance, metabolic rewiring such as aerobic glycolysis and glutamine
addiction of cancer cells leads to changes in the tumor microenvironment that increases secretion of
neurotrophins such as nerve growth factor and brain-derived neurotrophic factor, as well as pro-axonogenic
extracellular matrix components. Despite the obvious implications of blocking tumor innervation to reduce
metastatic frequency, the therapeutic potential of targeting metabolic rewiring to prevent breast tumor innervation
and curb metastasis has not yet been carefully evaluated.
Therefore, we hypothesize that aerobic glycolysis and glutamine addiction in breast cancer promotes breast
tumor innervation leading to heightened metastasis. To test our hypothesis, we will utilize our tissue-engineered
3D culture platforms that have been optimized in-house to study tumor innervation. Our platforms comprise
tumor-mimetic collagen fiber organization and breast tumor microenvironment-mimetic decellularized adipose
tissue matrices. Notably, our platform can be monitored longitudinally live using optical redox imaging to
determine cell type-specific metabolic changes and its correlation with innervation. We will evaluate the link
between metabolic rewiring in tumor cells and heightened innervation (Aim 1) and metastatic potential of breast
cancer cells as a function of the amount of tumor innervation (Aim 2). Aim 3 will focus on analysis of deidentified
patient samples from primary and metastatic breast tumors to unravel association among metabolic profiles,
innervation, and clinical metastatic outcomes. Mechanistic insights will be gained via pharmacological inhibitions
and genetic deletions of target metabolic enzymes and neurotrophin receptors. Outcomes of our research may
lead to not only knowledge gain on correlations among metabolic rewiring, innervation and metastasis, but also
novel strategies to curb metastatic breast cancer progression via interference on dysregulated cellular
metabolism and innervation. Importantly, our platforms can be broadened to study metabolic regulations of
cancer-nerve crosstalk in other types of non-neural cancers with proven malignant contributions from the nerves
via tumor innervation (e.g., lung, pancreas, colorectal, head and neck, skin, etc.).