Asadollahi, E. | Search bioRxiv

bioRxiv2026

The lncRNA SOX2OT Drives Non-Small Cell Lung Cancer Progression and Metastasis by Suppressing miR-143

In terms of cancer-related death, non-small cell lung cancer (NSCLC), the worlds leading cause, highlights the need for continued research into the genetic factors that influence tumor growth. Long non-coding RNAs (lncRNAs) are now well recognized as essential regulators of oncogenic signaling cascades; nevertheless, the specific role and molecular basis of the SOX2 overlapping transcript (SOX2OT) in NSCLC are not entirely understood. This study examined the functional importance of SOX2OT and its regulatory interactions with tumor-suppressive microRNAs in NSCLC cells. In A549 and Calu-3 cells, RNA interference-mediated SOX2OT silencing dramatically reduced cellular proliferation, migration, and invasiveness. Moreover, SOX2OT knockdown was associated with inhibition of epithelial-mesenchymal transition (EMT), alongside induction of cell cycle arrest and activation of apoptotic pathways. Integrated transcriptomic profiling and bioinformatic prediction analyses identified miR-143 as a putative downstream effector of SOX2OT activity. Consistently, depletion of SOX2OT resulted in marked elevation of miR-143 expression, which corresponded with downregulation of oncogenic mediators, including STAT3, EZH2, and CXCL13. As a result of SOX2OT suppression, both the transcript and the protein levels of PTEN were restored. Further functional characterization demonstrated that SOX2OT knockdown inhibits EMT progression by decreasing mesenchymal markers and EMT-related transcription factors (TFs) while concomitantly enhancing epithelial marker expression. Collectively, these findings suggest that SOX2OT contributes to NSCLC pathogenesis through regulation of a miR-143-centered signaling network that influences oncogenic signaling, cellular survival, and metastatic potential. Targeting the SOX2OT/miR-143 regulatory axis may therefore represent a promising therapeutic approach for NSCLC, while also underscoring the broader importance of lncRNA-mediated post-transcriptional regulation in lung cancer biology.

cancer biology↗

bioRxiv2022

Myelin lipids as nervous system energy reserves

Neuronal functions and impulse propagation depend on the continuous supply of glucose1,2. Surprisingly, the mammalian brain has no obvious energy stores, except for astroglial glycogen granules3. Oligodendrocytes make myelin for rapid axonal impulse conduction4 and also support axons metabolically with lactate5-7. Here, we show that myelin itself, a lipid-rich membrane compartment, becomes a local energy reserve when glucose is lacking. In the mouse optic nerve, a model white matter tract, oligodendrocytes survive glucose deprivation far better than astrocytes, by utilizing myelin lipids which requires oxygen and fatty acid beta-oxidation. Importantly, fatty acid oxidation also contributes to axonal ATP and basic conductivity. This metabolic support by fatty acids is an oligodendrocyte function, involving mitochondria and myelin-associated peroxisomes, as shown with mice lacking Mfp2. To study reduced glucose availability in vivo without physically starving mice, we deleted the Slc2a1 gene from mature oligodendrocytes. This caused a significant decline of the glucose transporter GLUT1 from the myelin compartment leading to myelin sheath thinning. We suggest a model in which myelin turnover under low glucose conditions can transiently buffer axonal energy metabolism. This model may explain the gradual loss of myelin in a range of neurodegenerative diseases8 with underlying hypometabolism9.

neuroscience↗