Biology subjects

Fabrowski, P.

Publications and source records attributed to Fabrowski, P..

3 recordsLinked to original sources

bioRxiv2024

Differential KEAP1/NRF2 mediated signaling widens the therapeutic window of redox-targeting drugs in SCLC therapy

Small cell lung cancer (SCLC) patients frequently experience a remarkable response to first-line therapy. Follow up maintenance treatments aim to control residual tumor cells, but generally fail due to cross-resistance, inefficient targeting of tumor vulnerabilities, or dose-limiting toxicity, resulting in relapse and disease progression. Here, we show that SCLC cells, similar to their cells of origin, pulmonary neuroendocrine cells (PNECs), exhibit low activity in pathways protecting against reactive oxygen species (ROS). When exposed to a novel thioredoxin reductase 1 (TXNRD1) inhibitor, these cells quickly exhaust their ROS-scavenging capacity, regardless of their molecular subtype or resistance to first-line therapy. Importantly, unlike non-cancerous cells, SCLC cells cannot adapt to drug-induced ROS stress due to the suppression of ROS defense mechanisms by multiple layers of epigenetic and transcriptional regulation. By exploiting this difference in oxidative stress management, we safely increased the therapeutic dose of TXNRD1 inhibitors in vivo by pharmacological activation of the NRF2 stress response pathway. This resulted in improved tumor control without added toxicity to healthy tissues. These findings underscore the therapeutic potential of TXNRD1 inhibitors for maintenance therapy in SCLC. Graphical summary O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=72 SRC="FIGDIR/small/621846v1_ufig1.gif" ALT="Figure 1"> View larger version (21K): org.highwire.dtl.DTLVardef@2a7336org.highwire.dtl.DTLVardef@f21de9org.highwire.dtl.DTLVardef@189d062org.highwire.dtl.DTLVardef@cff38b_HPS_FORMAT_FIGEXP M_FIG C_FIG Pharmacological induction of NRF2 leads to differential cyto-protection against TXNRD1 inhibitors in normal tissue but not in SCLC tumor cells. This results in a reduction of adverse effects, allowing to increase the therapeutic dose.

cancer biology↗

bioRxiv2023

Low level of antioxidant capacity biomarkers but not target overexpression predicts vulnerability to ROS-inducing drugs

Despite a strong rationale for why cancer cells are susceptible to redox-targeting drugs, such drugs often face tumor resistance or dose-limiting toxicity in preclinical and clinical studies. An important reason is the lack of specific biomarkers to better select susceptible cancer entities and stratify patients. Using a large panel of lung cancer cell lines, we identified a set of "antioxidant-capacity" biomarkers (ACB), which were tightly repressed, partly by STAT3 and STAT5A/B in sensitive cells, rendering them susceptible to multiple redox-targeting and ferroptosis-inducing drugs. Contrary to expectation, constitutively low ACB expression was not associated with an increased steady state level of reactive oxygen species (ROS) but a high level of nitric oxide, which is required to sustain high replication rates. Using ACBs, we identified cancer entities with a high percentage of patients with favorable ACB expression pattern, making it likely that more responders to ROS-inducing drugs could be stratified for clinical trials.

cancer biology↗

bioRxiv2022

Orphan nuclear receptors Err2 and 3 promote a feature-specific terminal differentiationprogram underlying gamma motor neuron function and proprioceptive movement control

Motor neurons are commonly thought of as mere relays between the central nervous system and the movement apparatus, yet, in mammals about one-third of them function exclusively as regulators of muscle proprioception. How these gamma motor neurons acquire properties to function differently from the muscle force-producing alpha motor neurons remains unclear. Here, we found that upon selective loss of the orphan nuclear receptors Err2 and Err3 (Err2/3) in mice, gamma motor neurons acquire characteristic structural (e.g. synaptic wiring), but not functional (e.g. physiological firing rates) properties necessary for regulating muscle proprioception, thus disrupting gait and precision movements in vivo. Moreover, Err2/3 operate via transcriptional activation of neural activity modulators, one of which (Kcna10) promoted gamma motor neuron functional properties. Our work identifies a long-sought mechanism specifying gamma motor neuron properties necessary for proprioceptive movement control, which implies a feature-specific terminal differentiation program implementing neuron subtype-specific functional but not structural properties. SummaryThe transcription factors Err2 and 3 promote functional properties in a subset of motor neurons necessary for executing precise movements.

neuroscience↗