Abstract A012: Aging drives TNBC lung metastasis dependency on FGFR-triggered metabolic reprogramming exposing an age-induced liability with therapeutic potential
Authors: Drapela Stanislav , Chang Shiun , Rad Rojan Chimeh , Rubio Vanessa , Ilter Didem , Rodriguez Paulo , Gomes Ana P. 
Published: November 2024

Abstract
The clinical manifestation of metastasis in a vital organ is the final stage of breast cancer progression and the main culprit of breast cancer related mortality. This remain especially problematic in the case of triple negative breast cancer (TNBC), the most aggressive type of breast cancer, often diagnosed in its metastatic form and for which chemotherapies are still the major therapeutic option. Typically, TNBC is seen as a disease of younger women, however, 20% of TNBCs occur in patients aged 65 and older, whose prognosis is equally staggering. Unfortunately, due to co-morbidities, tolerability of chemotherapies, as well as severe reduction in quality of life, majority of women above age 65 can’t or decide not to receive chemotherapy ultimately cutting their lives short. Metastatic outgrowth is largely dictated by the ability of TNBC disseminated cancer cells (DCCs) to thrive distal organs and is largely dependent on the physiology of the specific organs. However, how the aging process, a major driver of changes in organismal physiology, affects the interaction between the host organ and TNBC DCCs remains unknown. Here, we adapted several traditional syngeneic models of TNBC metastasis to old mice of different strains and coupled with RNA-seq to unveil molecular adaptations of TNBC DCCs to the aging lung. We show that the changes that occur in the lung with aging drives an increase in mitochondrial fitness in TNBC DCCs, an adaptation that is necessary for metastasis to thrive in the old lung environment. Mechanistically, our data show that the expression of FGF19, a gut hormone not normally expressed in TNBC DCCs, drives this increase in mitochondrial fitness in the old lung through an autocrine signaling axis impinging on activation of FGF-19 cognate receptor family, FGFRs. Inhibition of FGF19-FGFR signaling using an FDA- approved FGFR inhibitor not only blocks the age-induced increase in mitochondrial fitness but also effectively abolishes lung metastasis in old, but not in young, immune competent and immune compromised mice. We traced this to age-specific metastatic adaptation of TNBC lung metastasis to the increase in bile acids, the canonical regulators of FGF19 expression, in the old lung environment. Together, our work demonstrates an important contribution of age-driven metabolic reprogramming of the host to the traits that enable metastasis to thrive in the lung and provides rationale for the use of FDA-approved FGFR inhibitors for the treatment of breast cancer lung metastasis in the most vulnerable of stage IV metastatic TNBC patients, the elderly.
Citation Format: Stanislav Drapela, Shiun Chang, Rojan Chimeh Rad, Vanessa Rubio, Didem Ilter, Paulo Rodriguez, Ana P. Gomes. Aging drives TNBC lung metastasis dependency on FGFR-triggered metabolic reprogramming exposing an age-induced liability with therapeutic potential [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A012.