Upregulation of EID3 sensitizes breast cancer cells to ionizing radiation-induced cellular senescence

EID3 inhibits the osteogenic differentiation of periodontal ligament stem cells and mediates the signal transduction of TAZ-EID3-AKT/MTOR/ERK

Exploring the molecular mechanisms of cell behaviors is beneficial for promoting periodontal ligament stem cell (PDLSC)-mediated tissue regeneration. This study intends to explore the regulatory effects of EID3 on cell proliferation, apoptosis, and osteogenic differentiation and to preliminarily explore the regulatory mechanism of EID3. Here, EID3 was overexpressed or knocked down in PDLSCs by recombinant lentivirus. Then, cell proliferation activity was analyzed by colony-forming assay, EdU assay, and cell cycle assay. Cell apoptosis was detected by flow cytometry. The osteo-differentiation potential was analyzed using ALP activity assay, ALP staining, alizarin red staining, and mRNA and protein assay of osteo-differentiation related genes. The results showed that when EID3 was knocked down, the proliferation activity and osteogenic differentiation potential of PDLSCs decreased, while they increased when EID3 was overexpressed. The cell apoptosis rate decreased in PDLSCs with EID3 knockdown but increased in PDLSCs with EID3 overexpression. Moreover, EID3 inhibited the transduction of the AKT/MTOR and ERK signaling pathway. In addition, TAZ negatively regulated the expression of EID3, and the overexpression of EID3 partially reversed the promotive effects of TAZ on the osteogenic differentiation of PDLSCs. Taken together, EID3 inhibits the proliferation and osteogenic differentiation while promoting the apoptosis of PDLSCs. EID3 inhibits the transduction of the AKT/MTOR and ERK signaling pathways and mediates the regulatory effect of TAZ on PDLSC osteogenic differentiation.

EID3 Promotes Cancer Stem Cell-Like Phenotypes in Osteosarcoma through the Activation of PI3K-AKT Signaling Pathway

The aim of this study is to elucidate molecular mechanism by which E1A-like inhibitor of differentiation 3 (EID3) promotes cancer stem cell-like phenotypes in osteosarcoma. Overexpression of EID3 in osteosarcoma cells generated more spherical clones, enhanced the expression of stemness-associated genes, and promoted chemoresistance, invasion, and metastasis. Furthermore, osteosarcoma cells overexpressing EID3 had increased ability to grow in suspension as osteospheres with high expression of Sox2 and stem cell marker CD133. In addition, knockdown of EID3 reduced sphere formation and inhibited osteosarcoma cell migration and invasion. RNA sequencing and bioinformatics analysis revealed that PI3K-Akt signaling pathway and MAPK pathway­related genes were enriched in osteosarcoma cells with high expression of EID3. Taken together, EID3 promotes osteosarcoma, and EID3–PI3K-Akt axis is a potential therapeutic target for osteosarcoma treatment.

Cellular Senescence: Molecular Targets, Biomarkers, and Senolytic Drugs

Cellular senescence is defined as irreversible cell cycle arrest caused by various processes that render viable cells non-functional, hampering normal tissue homeostasis. It has many endogenous and exogenous inducers, and is closely connected with age, age-related pathologies, DNA damage, degenerative disorders, tumor suppression and activation, wound healing, and tissue repair. However, the literature is replete with contradictory findings concerning its triggering mechanisms, specific biomarkers, and detection protocols. This may be partly due to the wide range of cellular and in vivo animal or human models of accelerated aging that have been used to study senescence and test senolytic drugs. This review summarizes recent findings concerning senescence, presents some widely used cellular and animal senescence models, and briefly describes the best-known senolytic agents.

Comparative study of the transcriptomes of Caco-2 cells cultured under dynamic vs. static conditions following exposure to titanium dioxide and zinc oxide nanomaterials

Due to the widespread application of food-relevant inorganic nanomaterials, the gastrointestinal tract is potentially exposed to these materials. Gut-on-chip in vitro systems are proposed for the investigation of compound toxicity as they better recapitulate the in vivo human intestinal environment than static models, due to the added shear stresses associated with the flow of the medium. We aimed to compare cellular responses of intestinal epithelial Caco-2 cells at the gene expression level upon TiO₂ (E171) and ZnO (NM110) nanomaterial exposure when cultured under dynamic and conventionally applied static conditions. Whole-genome transcriptome analyses upon exposure of the cells to TiO₂ and ZnO nanomaterials revealed differentially expressed genes and related biological processes that were culture condition specific. The total number of differentially expressed genes (p < 0.01) and affected pathways (p < 0.05 and FDR < 0.25) after nanomaterial exposure was higher under dynamic culture conditions than under static conditions for both nanomaterials. The observed increase in nanomaterial-induced responses in the gut-on-chip model indicates that shear stress might be a major factor in cell susceptibility. This is the first report on the application of a gut-on-chip system in which gene expression responses upon TiO₂ and ZnO nanomaterial exposure are evaluated and compared to a static system. It extends current knowledge on nanomaterial toxicity assessment and the influence of a dynamic environment on cellular responses. Application of the gut-on-chip system resulted in higher sensitivity of the cells and might thus be an attractive system for use in the toxicological hazard characterization of nanomaterials.

Signature changes in the expressions of protein-coding genes, lncRNAs, and repeat elements in early and late cellular senescence

Replicative cellular senescence is the main cause of aging. It is important to note that early senescence is linked to tissue regeneration, whereas late senescence is known to trigger a chronically inflammatory phenotype. Despite the presence of various genome-wide studies, there is a lack of information on distinguishing early and late senescent phenotypes at the transcriptome level. Particularly, the changes in the noncoding RNA portion of the aging cell have not been fully elucidated. By utilising RNA sequencing data of fibroblasts, hereby, we are not only reporting changes in gene expression profiles and relevant biological processes in the early and late senescent phenotypes but also presenting significant differences in the expressions of many unravelled long noncoding RNAs (lncRNAs) and transcripts arisen from repetitive DNA. Our results indicate that, in addition to previously reported L1 elements, various LTR and DNA transposons, as well as members of the classical satellites including HSAT5 and α-satellites (ALR/Alpha), are expressed at higher levels in late senescence. Moreover, we revealed finer links between the expression levels of repeats with the genes located near them and known to be involved in cell cycle and senescence. Noncoding elements reported here provide a new perspective to be explored in further experimental studies.

The Premature Senescence in Breast Cancer Treatment Strategy

Cellular senescence is a permanent blockade of cell proliferation. In response to therapy-induced stress, cancer cells undergo apoptosis or premature senescence. In apoptosis-resistant cancer cells or at lower doses of anticancer drugs, therapy-induced stress leads to premature senescence. The role of this senescence in cancer treatment is discussable. First of all, the senescent cells lose the ability to proliferate, migrate, and invade. In addition, the senescent cells secrete a set of proteins (inflammatory cytokines, chemokines, growth factors) known as the senescence-associated secretory phenotype (SASP), which influences non-senescent normal cells and non-senescent cancer cells in the tumor microenvironment and triggers tumor promotion and recurrence. Recently, many studies have examined senescence induction through breast cancer therapy and potentially using this phenomenon to treat this cancer. This review summarizes the recent in vitro, in vivo, and clinical studies investigating senescence in breast cancer treatments. Senescence inductors, senolytics, as well as their action mechanism are discussed herein. Potential SASP-modulating treatment strategies are also described.

Formylation of a metathesis-derived ansa[4]-ferrocene: a simple route to anticancer organometallics

Ansa-Ferrocenealdehyde, obtained by formylation of a metathesis-derived ansa-ferrocene, was transformed into a conjugate with triazole and uracil with anticancer activity.