Lung adenocarcinoma (LUAD) is a prevalent type of thoracic cancer with a poor prognosis and high mortality rate. However, the exact pathogenesis of this cancer is still not fully understood. One potential factor that can contribute to the development of lung adenocarcinoma is DNA methylation, which can cause changes in chromosome structure and potentially lead to the formation of tumors. The baculoviral IAP repeat containing the 5 (BIRC5) gene encodes the Survivin protein, which is a multifunctional gene involved in cell proliferation, migration, and invasion of tumor cells. This gene is elevated in various solid tumors, but its specific role and mechanism in lung adenocarcinoma are not well-known. To identify the potential biomarkers associated with lung adenocarcinoma, we screened the methylation-regulated differentially expressed genes (MeDEGs) of LUAD via bioinformatics analysis. Gene ontology (GO) process and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were applied to investigate the biological function and pathway of MeDEGs. A protein–protein interaction (PPI) network was employed to explore the key module and screen hub genes. We screened out eight hub genes whose products are aberrantly expressed, and whose DNA methylation modification level is significantly changed in lung adenocarcinoma. BIRC5 is a bona fide marker which was remarkably up-regulated in tumor tissues. Flow cytometry analysis, lactate dehydrogenase release (LDH) assay and Micro-PET imaging were performed in A549 cells and a mouse xenograft tumor to explore the function of BIRC5 in cell death of lung adenocarcinoma. We found that BIRC5 was up-regulated and related to a high mortality rate in lung adenocarcinoma patients. Mechanically, the knockdown of BIRC5 inhibited the proliferation of A549 cells and induced pyroptosis via caspase3/GSDME signaling. Our findings have unraveled that BIRC5 holds promise as a novel biomarker and therapeutic target for lung adenocarcinoma. Additionally, we have discovered a novel pathway in which BIRC5 inhibition can induce pyroptosis through the caspase3-GSDME pathway in lung adenocarcinoma cells.

Liquid–liquid phase separation (LLPS), a fundamental biophysical process driven by multivalent weak interactions, regulates diverse cellular physiological functions. Ion channels are critical transmembrane protein complexes governing electrophysiological signaling, yet their phase separation characteristics remain largely uncharacterized. Here, we systematically assessed the phase-separation propensity of 140 human ion-channel proteins from the PhaSePred database, and 69 human ion channel proteins were predicted to have a high propensity for LLPS (prediction score ≥ 0.5). Based on the self-assembling phase-separating (PS-Self) and partner-dependent phase-separating (PS-Part) scores of the proteins, we classified ion channel proteins with a ratio (PS-Self/PS-Part) > 1 into the PS-Self group and those with a ratio < 1 into the PS-Part group. Ultimately, 37 proteins were predicted to tend toward PS-Self, and 32 to tend toward PS-Part. Moreover, PS-Self candidates exhibited higher hydropathy and pi–pi contact scores, whereas predicted PS-Part candidates showed higher IDR, LCR, and phosphorylation-associated scores. Experimental analyses identified intracellular regions of Ca_V1.2, Ca_V1.3, Na_V1.5, and K_Ca2.2 that formed dynamic condensate-like assemblies when expressed in HeLa cells. Our findings elucidate the phase separation classification and core structural domains mediating LLPS in key ion channels and providing a molecular basis for understanding the pathophysiological roles of ion channel phase separation in cardiac and neurological disorders and may inform the development of phase-separation-targeted diagnostic and therapeutic strategies.