ELK4 Promotes Cell Cycle Progression and Stem Cell-like Characteristics in HPV-associated Cervical Cancer by Regulating the FBXO22/PTEN Axis

ELK4 transcription promotes MSI2-mediated progression of non-small cell lung cancer through the TGF-β/SMAD3 pathway

Non-small cell lung cancer (NSCLC) is a primary contributor to global cancer-related mortality. Musashi-2 (MSI2), an RNA-binding protein (RBP), is upregulated in specific NSCLC tumor subgroups. The current investigation evaluated the role and underlying mechanism of MSI2 in NSCLC. The expression levels of ELK4, MSI2, SMAD3, p-SMAD3 and TGFβR1 were assessed via RT-qPCR or Western blot. Chromatin immunoprecipitation (ChIP) and dual luciferase reporter assays were used to confirm the interaction between ELK4 and MSI2. The proliferation, migration and invasion of NSCLC cells were determined via MTT, colony formation, and transwell assays, respectively. A xenograft tumor model was established in BALB/c nude mice. Immunohistochemical (IHC) staining was used to test Ki67 expression. We found that MSI2 and ELK4 expression levels were increased in NSCLC tissues and cells. ELK4 depletion suppressed the proliferation, migration and invasion of NSCLC cells. ELK4 acts as a transcription factor and promotes the transcription of MSI2. MSI2 depletion repressed NSCLC cell proliferation, migration and invasion through the TGF-β/SMAD3 pathway. Overexpression of ELK4 reversed the inhibitory effect of MSI2 repression on NSCLC progression. These results confirmed that ELK4 is a direct regulator of MSI2 expression and that MSI2 promotes NSCLC progression through TGF-β/SMAD3 activation, suggesting the potential clinical value of inhibiting MSI2 in NSCLC.

ETS-1 in tumor immunology: implications for novel anti-cancer strategies

ETS-1, a key member of the Erythroblast Transformation-Specific (ETS) transcription factor family, plays an important role in cell biology and medical research due to its wide expression profile and strong transcriptional regulation ability. It regulates fundamental biological processes, including cell proliferation, differentiation, and apoptosis, and is involved in tumorigenesis and metastasis, promoting malignant behaviors such as angiogenesis, matrix degradation, and cell migration. Given the association between ETS-1 overexpression and the aggressive characteristics of multiple malignancies, it represents a promising therapeutic target in cancer treatment. This study aims to systematically analyze the role of ETS-1 within the tumor immune microenvironment, elucidating its mechanisms in cancer initiation, progression, and metastasis. It also investigates the differential expression of ETS-1 across tumor tissues and adjacent normal tissues, exploring its potential as a molecular marker for tumor diagnosis and prognosis.

Longitudinal Assessment of Nasopharyngeal Biomarkers Post-COVID-19: Unveiling Persistent Markers and Severity Correlations

SARS-CoV-19 infection provokes a variety of symptoms; most patients present mild/moderate symptoms, whereas a small proportion of patients progress to severe illness with multiorgan failure accompanied by metabolic disturbances requiring ICU-level care. Given the importance of the disease, researchers focused on identifying severity-associated biomarkers in infected patients as well as markers associated with patients suffering long-COVID. However, little is known about the presence of biomarkers that remain a few years after SARS-CoV-2 infection once the patients fully recover of the symptoms. In this study, we evaluated the presence of persistent biomarkers in the nasopharyngeal tract two years after SARS-Cov-2 infection in fully asymptomatic patients, taking into account the severity of their infection (mild/moderate and severe infections). In addition to the direct identification of several components of the Coronavirus Infection Pathway in those individuals that suffered severe infections, we describe herein 371 proteins and their associated canonical pathways that define the different adverse effects of SARS-CoV-2 infections. The persistence of these biomarkers for up to two years after infection, along with their ability to distinguish the severity of the infection endured, highlights the surprising presence of persistent nasopharyngeal exudate changes in fully recovered patients.

CircNUP98 promotes the malignant behavior of glioma cells through the miR-520f-3p/ELK4 axis

Glioma, a formidable form of brain cancer, poses significant challenges in terms of treatment and prognosis. Circular RNA nucleoporin 98 (circNUP98) has emerged as a potential regulator in various cancers, yet its role in glioma remains unclear. Here, we elucidate the functional role of circNUP98 in glioma cell proliferation, invasion, and migration, shedding light on its therapeutic implications. Glioma cells were subjected to si-NUP98 transfection, followed by assessments of cell viability, proliferation, invasion, and migration. Subcellular localization of circNUP98 was determined, and its downstream targets were identified. We delineated the binding relationships between circNUP98 and microRNA (miR)-520f-3p, as well as between miR-520f-3p and ETS transcription factor ELK4 (ELK4). The expression levels of circNUP98/miR-520f-3p/ELK4 were quantified. Our findings demonstrated that circNUP98 was upregulated in glioma cells, and its inhibition significantly attenuated glioma cell proliferation, invasion, and migration. Mechanistically, circNUP98 functioned as a sponge for miR-520f-3p, thereby relieving the inhibitory effect of miR-520f-3p on ELK4. Moreover, inhibition of miR-520f-3p or overexpression of ELK4 partially rescued the suppressive effect of circNUP98 knockdown on glioma cell behaviors. In summary, our study unveils that circNUP98 promotes glioma cell progression via the miR-520f-3p/ELK4 axis, offering novel insights into the therapeutic targeting of circNUP98 in glioma treatment.

ELK4 targets CHMP6 to inhibit ferroptosis and enhance malignant properties of skin cutaneous melanoma cells

Ferroptosis, a key factor in tumor progression, is poorly understood at the molecular level. This study investigates how ELK4 and CHMP6 regulate skin cutaneous melanoma (SKCM) cell proliferation and ferroptosis. Analysis of TCGA data reveals high expression of ELK4 and CHMP6 in SKCM. Overexpression of ELK4 or CHMP6 enhances cell proliferation, invasion, and migration while reducing ROS and Fe2 + levels. It also increases GPX4 and xCT expression and decreases ACSL4 levels in SKCM cells. The opposite effects are observed with ELK4 or CHMP6 knockdown. ELK4 binds to the CHMP6 promoter, promoting CHMP6 transcription. Knockdown of CHMP6 reverses the oncogenic effects of ELK4 overexpression. In conclusion, ELK4 enhances proliferation, invasion, and migration while inhibiting ferroptosis in SKCM cells by upregulating CHMP6 transcription. This study sheds light on the intricate mechanisms involved in SKCM progression and identifies potential therapeutic targets in melanoma treatment.

miR-129-5p inhibits anchorage-independent growth through silencing of ACTN1 and the ELK4/c-FOS axis in HPV-transformed keratinocytes

A persistent infection with human papillomavirus (HPV) can induce precancerous lesions of the cervix that may ultimately develop into cancer. Cervical cancer development has been linked to altered microRNA (miRNA) expression, with miRNAs regulating anchorage-independent growth being particularly important for the progression of precancerous lesions to cancer. In this study, we set out to identify and validate targets of miR-129-5p, a previously identified tumor suppressive miRNA involved in anchorage-independent growth and HPV-induced carcinogenesis. We predicted 26 potential miR-129-5p targets using online databases, followed by KEGG pathway enrichment analysis. RT-qPCR and luciferase assays confirmed that 3'UTR regions of six genes (ACTN1, BMPR2, CAMK4, ELK4, EP300, and GNAQ) were targeted by miR-129-5p. Expressions of ACTN1, CAMK4, and ELK4 were inversely correlated to miR-129-5p expression in HPV-transformed keratinocytes, and their silencing reduced anchorage-independent growth. Concordantly, miR-129-5p overexpression decreased protein levels of ACTN1, BMPR2, CAMK4 and ELK4 in anchorage-independent conditions. Additionally, c-FOS, a downstream target of ELK4, was downregulated upon miR-129-5p overexpression, suggesting regulation through the ELK4/c-FOS axis. ACTN1 and ELK4 expression was also upregulated in high-grade precancerous lesions and cervical cancers, supporting their clinical relevance. In conclusion, we identified six targets of miR-129-5p involved in the regulation of anchorage-independent growth, with ACTN1, BMPR2, ELK4, EP300, and GNAQ representing novel targets for miR-129-5p. For both ACTN1 and ELK4 functional and clinical relevance was confirmed, indicating that miR-129-5p-regulated ACTN1 and ELK4 expression contributes to HPV-induced carcinogenesis.