OTUB1 promotes colorectal cancer progression by stabilizing GPX4 and inhibiting ferroptosis
摘要
Therapeutic resistance in colorectal cancer (CRC) is frequently linked to dysregulated protein homeostasis, which enables tumor cells to evade cell death. The ubiquitin-proteasome system (UPS) plays a pivotal role in regulating protein stability and has been implicated in ferroptosis, an iron-dependent form of cell death driven by lipid peroxidation. Otubain1 (OTUB1), a deubiquitinase within the UPS, is hypothesized to regulate ferroptosis by stabilizing GPX4, a key inhibitor of ferroptosis.
AimThis study investigates the regulatory role of OTUB1 in ferroptosis through its interaction with GPX4, aiming to uncover a novel therapeutic axis for CRC.
MethodsOTUB1 expression was manipulated in CRC cells using siRNA-mediated knockdown and plasmid-based overexpression. GPX4 expression, ROS levels, lipid peroxidation, and cell viability were assessed using qRT-PCR, Western blotting, and functional assays. Co-immunoprecipitation (Co-IP) assay was performed to confirm the interaction between OTUB1 and GPX4.
ResultsOTUB1 knockdown led to a significant reduction in GPX4 protein levels, leading to elevated ROS, increased lipid peroxidation, and decreased cell viability. Conversely, GPX4 overexpression in OTUB1-knockdown cells restored cell viability and reversed ferroptosis markers (P < 0.01). Co-IP assay confirmed that OTUB1 interacted with GPX4 and prevented its ubiquitin-mediated degradation, thereby stabilizing GPX4.
ConclusionThis study identifies OTUB1 as a novel regulator of ferroptosis in CRC through the stabilization of GPX4. Targeting the OTUB1-GPX4 axis may provide a new therapeutic approach for inducing ferroptosis in CRC cells, potentially overcoming resistance to conventional therapies and improving patient outcomes.