Atreya, A. | bioRxiv Science

bioRxiv2025

NELFA-mediated promoter-proximal pausing restrains YAP-driven transcription and shapes context-dependent outcomes in breast cancer

Overexpression of YAP is associated with tumor progression in multiple malignancies. YAP is the key transcriptional effector of Hippo signaling: a conserved pathway from Drosophila (Yki) to humans (YAP). In a Drosophila screen, we identified NELFA, a core component of the promoter-proximal pausing (PPP) complex, as a suppressor of Yki-driven hyperproliferation. We investigated whether PPP-YAP regulatory interaction is conserved in mammalian system. In HEK293T and MDA-MB-231 cells, we demonstrate that NELFA depletion amplifies YAP-driven transcription. Whole-transcriptome analysis of MDA-MB-231 cells revealed widespread reprogramming upon NELFA loss, with strong enrichment of YAP signatures, EMT and TGF-{beta} transcriptional networks--indicating that NELFA regulates a broad YAP-centered gene regulatory module. Clinical analysis of two independent breast cancer cohorts revealed a context-dependent role for NELFA. Low NELFA expression predicted poor disease-free survival in YAP-high tumors--particularly in triple-negative breast cancer (TNBC)--suggesting a tumor-suppressive role. While High NELFA expression correlated with poorer overall survival in all the subtypes. These findings confirm that NELFAs role in YAP-driven transcription is conserved in mammalian system and it manifests in a context-dependent manner in the breast cancer.

cancer biology↗

bioRxiv2025

Delayed protective effect of chronic variable stress on optic tract axonal degeneration after experimental TBI

Of the 2.8 million individuals who seek medical attention for traumatic brain injury (TBI) each year, nearly 300,000 require hospitalization, with up to 60% of these needing intensive care. Intensive care treatment of TBI involves stressful events such as sleep disruption, noise, and painful procedures, potentially leading to chronic stress in patients undergoing such treatment. Given that physiologic stress can exacerbate neuroinflammation and impair normal neural function, we hypothesized that chronic variable stress (CVS) following TBI would exacerbate behavioral and pathological outcomes. We tested this hypothesis by subjecting adolescent male mice to blunt TBI, followed by two weeks of CVS or control conditions. We assessed brain pathologic responses to injury 2-, 5-, 20-, and 28-weeks post-injury. We found chronic optic tract degeneration by Fluoro-jade B staining in TBI groups. Unexpectedly, CVS+TBI mice did not show evidence of optic tract axon degeneration 20 weeks after injury, but did at the other time points. CVS led to increased microglial phagocytic markers early after injury, regardless of TBI status, and TBI led to increased microglial phagocytic markers in a delayed fashion as well. Notably, microglial phagocytosis markers were not elevated in TBI+CVS groups compared to TBI only groups 20 weeks post-injury. There was no effect of TBI or CVS on behavioral measures taken at the end of CVS. These findings suggest a delayed, but not permanent, protective effect on axonal degeneration after TBI, potentially related to altered microglial and astrocytic phagocytic activity.

neuroscience↗