Abstract 1305: Brief pulses of high-level fluid shear stress enhance metastatic potential and rapidly alters the metabolism of cancer cells

Abstract During their journey through the circulation, circulating tumor cells (CTCs) face challenges to their survival including mechanical stresses related to their dynamic fluid microenvironment and oxidative stress related to their detached cell state. Recently, we identified a mechano-adaptive response to transient fluid shear stress (FSS) exposure that enables cancer cells to survive mechanical destruction in the circulation and found that it involves an increase in the activation of RhoA-actomyosin signaling (Moose et al., Cancer Cell 2020). Because RhoA is likely to influence other phenotypes involved in metastasis, such as invasiveness, we hypothesized that activation of RhoA by FSS may promote metastatic behavior in CTCs. Here we find that cancer cells (PC-3, MDA-MB-231, Myc-CaP) exposed to brief pulses of high-level FSS (∼1msec, τ =750-6400 dynes/cm2) exhibit enhanced invasiveness (dependent on RhoA) and anchorage-independent proliferation in vitro and enhanced metastatic colonization/tumor formation in vivo as compared to static controls. To investigate how exposure to FSS confers these phenotypes, we conducted transcriptomic and metabolomic profiling. Transcriptomic analysis at 3, 6, and 24h post FSS exposure revealed enrichment of gene expression involved in oxidative phosphorylation. Consistent with this, we found elevated oxygen consumption of cells exposed to FSS at 24h. Metabolomic profiling of cells immediately after exposure to FSS demonstrated rapid energy utilization consistent with actin remodeling and contractility as well as depletion of amino acids acids associated with the folate pathway. Cells exposed to FSS exhibit a reduced reactive oxygen species burden as compared to static controls. Consistent with the hypothesis that FSS-dependent activation of the folate pathway reduces oxidative burden in cells exposed to FSS, we found that exposure of cancer cells with the folate inhibitor methotrexate, sensitized those cells destruction by FSS. Taken together our data indicate that cancer cells that survive exposure brief pulses of FSS are primed for metastatic colonization in part through rapid metabolic programming that enables them to withstand oxidative stress associated with cell detachment. Thus, some CTCs may derive an unexpected survival benefit through encountering FSS in the circulation. Citation Format: Amanda N. Pope, Devon L. Moose, Sujata Birua, Guy O. Hudson, Hank Weresh, Patrick Breheny, Michael D. Henry. Brief pulses of high-level fluid shear stress enhance metastatic potential and rapidly alters the metabolism of cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 1305.