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Biology subjects

Willey, C.

Publications and source records attributed to Willey, C..

2 recordsLinked to original sources

Circadian Dysregulation in Aging Alters Senescence and Inflammatory Pathways in a Sex- and Time-of-Day Dependent Manner

The circadian rhythm orchestrates gene expression and critical physiological processes but becomes disrupted with aging, contributing to disease. How this disruption interacts with cellular senescence--a key driver of aging pathology--remains poorly defined. We studied renal gene expression at four timepoints over 24hrs in 6- and 24-month-old genetically diverse UM-HET3 mice of both sexes and performed complementary analyses in synchronized fibroblasts sampled at seven timepoints. Aging dysregulated core clock relationships, including loss of the canonical anti-phase expression between Bmal1 and Per2. Senescence-associated genes were not static but exhibited pronounced oscillations, with senescence phenotypes varying by sex and time of day. Differential expression analysis revealed immune activation, metabolic rewiring, and epigenetic changes that were sex- and time-dependent. Variance analysis uncovered increased transcriptional noise in aging, particularly in circadian-regulated pathways such as RNA splicing, ribosome biogenesis, and TOR signaling. Single-nucleus RNA-Seq identified two cell populations lacking the normal Bmal1-Cdkn1a expression relationship: one senescent-like and another profibrotic, revealing distinct cell states linked to circadian dysregulation. Fibroblasts recapitulated key age-related circadian changes seen in the kidneys, including phase shifts in mTOR and oxidative phosphorylation. Together, this work demonstrates that senescence phenotypes are dynamic, sex-specific, and time-of-day dependent, and introduces a new framework for detecting senescent cells based on circadian gene relationships. These findings underscore the need to integrate temporal context into aging research and therapeutic strategies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=185 HEIGHT=200 SRC="FIGDIR/small/709919v1_ufig1.gif" ALT="Figure 1"> View larger version (86K): org.highwire.dtl.DTLVardef@247e70org.highwire.dtl.DTLVardef@1e8f66borg.highwire.dtl.DTLVardef@18a0673org.highwire.dtl.DTLVardef@ad91d7_HPS_FORMAT_FIGEXP M_FIG C_FIG

genetics↗

Fibroblast growth factor receptor facilitates recurrence of minimal residual disease following trastuzumab emtansine therapy

Trastuzumab-emtansine (T-DM1) is an antibody-drug conjugate (ADC) that efficiently delivers a potent microtubule inhibitor into HER2 overexpressing tumor cells. However, resistance to T-DM1 is emerging as a significant clinical problem. Continuous in vitro treatment of HER2-transformed mammary epithelial cells with T-DM1 did not elicit spontaneously resistant cells. However, induction of epithelial-mesenchymal transition (EMT) via pretreatment with TGF-{beta}1 facilitated acquisition of T-DM1 resistance. Flow cytometric analyses indicated that induction of EMT decreased trastuzumab binding, prior to overt loss of HER2 expression. Kinome analyses of T-DM1 resistant cells indicated increased phosphorylation of ErbB1, ErbB4, and fibroblast blast growth factor receptor 1 (FGFR1). T-DM1 resistant cells failed to respond to the ErbB kinase inhibitors lapatinib and afatinib, but they acquired sensitivity to FIIN4, a covalent FGFR kinase inhibitor. In vivo, T-DM1 treatment led to robust regression of HER2-transformed tumors, but minimal residual disease (MRD) was still detectable via bioluminescent imaging. Upon cessation of the ADC relapse occurred and secondary tumors were resistant to additional rounds of T-DM1, but this recurrent tumor growth could be inhibited by FIIN4. Expression of FGFR1 was upregulated in T-DM1 resistant tumors, and ectopic overexpression of FGFR1 was sufficient to enhance tumor growth, diminish trastuzumab binding, and promote recurrence following T-DM1-induced MRD. Finally, patient-derived xenografts from a HER2+ breast cancer patient who had progressed on trastuzumab failed to respond to T-DM1, but tumor growth was significantly inhibited by FIIN4. Overall, our studies strongly support therapeutic combination of TDM1 and FGFR targeted agents in HER2+ breast cancer.

cancer biology↗