EPS8 phosphorylation by Src modulates its oncogenic functions

Exercise may improve lung immunity after surgical stress: Evidence from a nephrectomy model via a bioinformatic analysis

Exercise offers numerous benefits to cancer patients and plays an essential role in postsurgical cancer rehabilitation. However, there is a lack of research examining the effects of exercise after the surgical stress of nephrectomy. To address this gap, we created an animal model that simulated patients who had undergone nephrectomy with or without an exercise intervention. Next, we performed a bioinformatic analysis based on the data generated by the RNA sequencing of the lung tissue sample. An overrepresentation analysis was conducted using two genome databases (Gene Ontology and Kyoto Encyclopedia of Genes and Genomes [KEGG]). A KEGG analysis of the exercise-treated nephrectomy mice revealed enrichment in immune-related pathways, particularly in the NF-κB and B cell-related pathways. The expression of CD79A and IGHD, which are responsible for B cell differentiation and proliferation, was upregulated in the nephrectomy mice. Differential gene expression was categorized as significantly upregulated or downregulated according to nephrectomy and exercise groups. Notably, we identified several gene expression reversals in the nephrectomy groups with exercise that were not found in the nephrectomy without exercise or control groups. Our preliminary results potentially reveal a genetic landscape for the underlying mechanisms of the effects of exercise on our nephrectomy model.

Chlamydia repurposes the actin-binding protein EPS8 to disassemble epithelial tight junctions and promote infection

Invasive microbial pathogens often disrupt epithelial barriers, yet the mechanisms used to dismantle tight junctions are poorly understood. Here, we show that the obligate pathogen Chlamydia trachomatis uses the effector protein TepP to transiently disassemble tight junctions early during infection. TepP alters the tyrosine phosphorylation status of host proteins involved in cytoskeletal regulation, including the filamentous actin-binding protein EPS8. We determined that TepP and EPS8 are necessary and sufficient to remodel tight junctions and that the ensuing disruption of epithelial barrier function promotes secondary invasion events. The genetic deletion of EPS8 renders epithelial cells and endometrial organoids resistant to TepP-mediated tight junction remodeling. Finally, TepP and EPS8 promote infection in murine models of infections, with TepP mutants displaying defects in ascension to the upper genital tract. These findings reveal a non-canonical function of EPS8 in the disassembly of epithelial junctions and an important role for Chlamydia pathogenesis.

Ubiquitin-Specific Protease 6 n-Terminal-like Protein (USP6NL) and the Epidermal Growth Factor Receptor (EGFR) Signaling Axis Regulates Ubiquitin-Mediated DNA Repair and Temozolomide-Resistance in Glioblastoma

Glioblastoma multiforme (GBM) is the most malignant glioma, with a 30–60% epidermal growth factor receptor (EGFR) mutation. This mutation is associated with unrestricted cell growth and increases the possibility of cancer invasion. Patients with EGFR-mutated GBM often develop resistance to the available treatment modalities and higher recurrence rates. The drug resistance observed is associated with multiple genetic or epigenetic factors. The ubiquitin-specific protease 6 N-terminal-like protein (USP6NL) is a GTPase-activating protein that functions as a deubiquitinating enzyme and regulates endocytosis and signal transduction. It is highly expressed in many cancer types and may promote the growth and proliferation of cancer cells. We hypothesized that USP6NL affects GBM chemoresistance and tumorigenesis, and that its inhibition may be a novel therapeutic strategy for GBM treatment. The USP6NL level, together with EGFR expression in human GBM tissue samples and cell lines associated with therapy resistance, tumor growth, and cancer invasion, were investigated. Its pivotal roles and potential mechanism in modulating tumor growth, and the key mechanism associated with therapy resistance of GBM cells, were studied, both in vitro and in vivo. Herein, we found that deubiquitinase USP6NL and growth factor receptor EGFR were strongly associated with the oncogenicity and resistance of GBM, both in vitro and in vivo, toward temozolomide, as evidenced by enhanced migration, invasion, and acquisition of a highly invasive and drug-resistant phenotype by the GBM cells. Furthermore, abrogation of USP6NL reversed the properties of GBM cells and resensitized them toward temozolomide by enhancing autophagy and reducing the DNA damage repair response. Our results provide novel insights into the probable mechanism through which USP6NL/EGFR signaling might suppress the anticancer therapeutic response, induce cancer invasiveness, and facilitate reduced sensitivity to temozolomide treatment in GBM in an autolysosome-dependent manner. Therefore, controlling the USP6NL may offer an alternative, but efficient, therapeutic strategy for targeting and eradicating otherwise resistant and recurrent phenotypes of aggressive GBM cells.