Cell Biology International最新文献

Chronic obstructive pulmonary disease (COPD) is a pervasive and incapacitating respiratory condition, distinguished by airway inflammation and the remodeling of the lower respiratory tract. Central to its pathogenesis is an intricate inflammatory process, wherein macrophages exert significant regulatory functions, and High mobility group box 1 (HMGB1) emerges as a pivotal inflammatory mediator potentially driving COPD progression. This study explores the hypothesis that HMGB1, within macrophages, modulates COPD through inflammatory mechanisms, focusing on its influence on macrophage polarization. Our investigation uncovered that HMGB1 is upregulated in the context of COPD, associated with an enhanced proinflammatory M1 macrophage polarization induced by cigarette smoke. This polarization is linked to suppressed cell proliferation and induced apoptosis, indicative of HMGB1's role in the disease's inflammatory trajectory. The study further implicates HMGB1 in the activation of the Nuclear factor kappa-B (NF-κB) signaling pathway and chemokine signaling within macrophages, which are likely to amplify the inflammatory response characteristic of COPD. The findings underscore HMGB1's critical involvement in COPD pathogenesis, presenting it as a significant target for therapeutic intervention aimed at modulating macrophage polarization and inflammation.

Crizotinib, as the first-generation of anaplastic lymphoma kinase (ALK) inhibitor, effectively improves the survival time of ALK-positive non-small cell lung cancer (NSCLC) patients. However, its efficacy is severely limited by drug resistance caused by secondary mutations. G1202R and L1196M are classical mutation sites located in ALK kinase domain. They may hinder the binding of ALK inhibitors to the target kinase domain, resulting in drug resistance in patients. However, the exact mechanism of drug resistance mediated by these mutations remains unclear. In this study, we aimed to evaluate how G1202R and L1196M mutations mediate crizotinib resistance. To explore the resistance mechanism, we constructed EML4-ALK G1202R and L1196M mutant cell lines with A549 cells. The results showed that the mutant cells exhibited significant epithelial–mesenchymal transition (EMT) and metastasis compared to control (A549-vector) or wild type (A549-EML4-ALK) cells. Subsequently, it was found that the occurrence of EMT was correlated to the high expression of murine double minute 2 (MDM2) protein and the activation of mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway in mutant cells. Down-regulation of MDM2 inhibited the activation of MEK/ERK pathway, thus reversed the EMT process and markedly increased the inhibitory effect of crizotinib on the growth of mutant cells. Collectively, resistance of ALK-positive NSCLC cells to crizotinib is induced by G1202R and L1196M mutations through activation of the MDM2/MEK/ERK signalling axis, promoting EMT process and metastasis. These findings suggest that the combination of MDM2 inhibitors and crizotinib could be a potential therapeutic strategy.

Erucic acid (ErA) is a source of omega-9 monounsaturated fatty acids. ErA exhibited antitumor effects by causing apoptosis and oxidative stress in tumor cells, with the exception of the HT-29 human colorectal cancer cell line. The apoptotic and Ca²⁺ signaling pathways in tumor cells are triggered when mitochondrial Ca²⁺ and Zn²⁺ accumulation produce reactive free oxygen species (ROS), which in turn activate TRPM2. ErA-induced ROS and TRPM2 stimulation may augment the anticancer action of cisplatin (CSP). We aimed to study the effects of ErA and CSP incubations on ROS, apoptosis, and cell death in the HT-29 cells by activating TRPM2. The cells were divided into five groups: control, ErA (200 µM for 48 h), CSP (25 µM for 24 h), and ErA + CSP + TRPM2 antagonists (200 µM carvacrol and 25 µM N-(p-amylcinnamoyl)anthranilic acid for 24 h). The TRPM2 antagonists reduced ErA plus CSP-induced increases in H₂O₂-induced intracellular free Ca²⁺ concentration ([Ca²⁺]_c) and adenosine diphosphate-ribose-caused TRPM2 currents. ErA and CSP were found to cause apoptosis and cell death by raising the intracellular free Zn²⁺ concentration (Zn²⁺]_c), caspase-3, −8, and −9, mitochondrial membrane dysfunction, and ROS, while lowering reduced glutathione, cell viability, and cell number. The oxidative, apoptotic, and tumor cell death effects of CSP in the cells were enhanced by the increase of ErA-mediated [Ca²⁺]_c and Zn²⁺]_c entering mitochondria through the activation of TRPM2. In conclusion, we observed that the combination of ErA and CSP was synergistic via TRPM2 activation for the treatment of HT-29 tumor cells.

Pax-6 emerges as a critical transcription factor that guides the fate of stem cells towards neural lineages. Its expression influences the differentiation of neural progenitors into diverse neuronal subtypes, glial cells, and other neural cell types. Pax-6 operates with other regulatory factors to ensure the precise patterning and organization of the developing nervous system. The intricate interplay between Pax-6 and other signaling pathways, transcription factors, and epigenetic modifiers underpins the complicated balance between stem cell maintenance, proliferation, and differentiation in neuroectodermal and ocular contexts. Dysfunction of Pax-6 can lead to a spectrum of developmental anomalies, underscoring its importance in these processes. This review highlights the essential role of Pax-6 expression in neuroectodermal and ocular stem cells, shedding light on its significance in orchestrating the intricate journey from stem cell fate determination to the emergence of diverse neural and ocular cell types. The comprehensive understanding of Pax-6 function gained from a developmental biology perspective offers valuable insights into normal development and potential therapeutic avenues for neuroectodermal and ocular disorders.

Hypoxia-induced heterogeneity in colorectal cancer (CRC) significantly impacts patient survival by promoting chemoresistance. These conditions alter the regulation of miRNAs, key regulators of crucial processes like proliferation, apoptosis, and invasion, leading to tumor progression. Despite their promising potential as diagnostic and therapeutic targets, the underlying mechanisms by which miRNAs influence hypoxia-mediated tumorigenesis remain largely unexplored. This study aims to elucidate the action of miRNAs in HCT-116 colorectal cancer stem cells (CSCs) under hypoxia, providing valuable insights into their role in tumor adaptation and progression. MiRNA expression was determined using Nanostring nCounter, and bioinformatic analysis was performed to explain the molecular pathway. A total of 50 miRNAs were obtained with an average count of ≥ 20 reads for comparative expression analysis. The results showed that hypoxia-affected 36 oncomiRs were increased in HCT-116, and 14 suppressor-miRs were increased in MSCs. The increase in miRNA expression occurred consistently from normoxia to hypoxia and significantly differed between mesenchymal stem cells (MSCs) and HCT-116. Furthermore, miR-16-5p and miR-29a-3p were dominant in regulating the p53 signaling pathway, which is thought to be related to the escape mechanism against hypoxia and maintaining cell proliferation. More research with a genome-transcriptome axis approach is needed to fully understand miRNAs’ role in adapting CRC cells and MSCs to hypoxia. Further research could focus on developing specific biomarkers for diagnosis. In addition, anti-miR can be developed as a therapy to prevent cancer proliferation or inhibit the adaptation of cancer cells to hypoxia.

Cytotoxic CD8⁺ T cells plays a pivotal role in the adaptive immune system to protect the organism against infections and cancer. During activation and response, T cells undergo a metabolic reprogramming that involves various metabolic pathways, with a predominant reliance on glycolysis to meet their increased energy demands and enhanced effector response. Recently, extracellular vesicles (EVs) known as exosomes have been recognized as crucial signaling mediators in regulating the tumor microenvironment (TME). Recent reports indicates that exosomes may transfer biologically functional molecules to the recipient cells, thereby facilitate cancer progression, angiogenesis, metastasis, drug resistance, and immunosuppression by reprogramming the metabolism of cancer cells. This study sought to enlighten possible involvement of cancer-derived exosomes in CD8 + T cell glucose metabolism and discover a regulated signalome as a mechanism of action. We observed reduction in glucose metabolism due to downregulation of AKT/mTOR signalome in activated CD8 + T cells after cancer derived exosome exposure. In-vivo murine breast tumor studies showed better tumor control and antitumor CD8 + T cell glycolysis and effector response after abrogation of exosome release from breast cancer cells. Summarizing, the present study establishes an immune evasion mechanism of breast cancer cell secreted exosomes that will act as a foundation for future precision cancer therapeutics.

Radioresistance is a major obstacle for the therapy of esophageal squamous cell carcinoma (ESCC) and lead to a poor prognosis. Ferroptosis is supposed to be responsible for radioresistance. However, the ferroptosis-induced radioresistance in ESCC and its related regulatory mechanisms are not yet fully understood. In this study, human ESCC cell line and the corresponding radioresistance cells were irradiated with 6 megavolts (MV) X-ray. It was showed that irradiation led to less ferroptosis in radioresistant ESCC cells as compared to the parental cells, as depicted by transmission electron microscopy, intracellular Fe²⁺ iron contents, lipid peroxidation, and expression of COX2. The increase of ASCL4 expression levels in radioresistant cells after radiotherapy was smaller than that in the parental cells. ACSL4 overexpression significantly enhanced ferroptosis. The fold increase in ACSL4 m⁶A modification in the radioresistant cells was significantly smaller than that in the parental cells as detected by methylated RNA immunoprecipitation with qRT-PCR. METTL14 overexpression accelerated ferroptosis induced by irradiation via upregulating m⁶A modification of ACSL4 mRNA. In conclusions, ferroptosis ablation was responsible for the radioresistant of ESCC. The METTL14-mediated m⁶A modification of ACSL4 mRNA sensitized ESCC to irradiation via accelerating ferroptosis. This study sheds new light on our understanding of radioresistant in ESCC, and provides potential strategies for ESCC radiotherapy.

Ectophosphatases catalyse the hydrolysis of phosphorylated molecules, such as phospho-amino acids, in the extracellular environment. Nevertheless, the hydrolysis of nucleotides in the extracellular environment is typically catalysed by ectonucleotidases. Studies have shown that acid ectophosphatase, or transmembrane-prostatic acid phosphatase (TM-PAP), a membrane-bound splice variant of prostatic acid phosphatase, has ecto-5′-nucleotidase activity. Furthermore, it was demonstrated that ectophosphatase cannot hydrolyse ATP, ADP, or AMP in triple-negative breast cancer cells. In contrast to previous findings in MDA-MB-231 cells, the ectophosphatase studied in the present work displayed a remarkable capacity to hydrolyse AMP in luminal A breast cancer cells (MCF-7). We showed that AMP dose-dependently inhibited p-nitrophenylphosphate (p-NPP) hydrolysis. The p-NPP and AMP hydrolysis showed similar biochemical behaviours, such as increased hydrolysis under acidic conditions and comparable inhibition by NiCl₂, ammonium molybdate, and sodium orthovanadate. In addition, this ectophosphatase with ectonucleotidase activity was essential for the release of adenosine and inorganic phosphate from phosphorylated molecules available in the extracellular microenvironment. This is the first study to show that prostatic acid phosphatase on the membrane surface of breast cancer cells (MCF-7) is correlated with cell adhesion and migration.

The establishment of fibroblast lines enables several applications from the formation of biobanks for the conservation of biodiversity to the use of these cells in physiological and toxicological assays. Considered a species vulnerable to extinction, the characterization of fibroblastic lines of northern tiger cat would contribute to its conservation. Therefore, we established and characterized fibroblasts derived from northern tiger cat during extended passage (third, seventh, and eleventh passages) and cryopreservation with regard to the morphology, viability, apoptotic classification, metabolism, proliferative activity, and oxidative stress by reactive oxygen species (ROS) levels and mitochondrial membrane potential (ΔΨm). Initially, we identified four dermal fibroblast lines by morphology, immunophenotyping, and karyotyping assays. In vitro culture after the third, seventh, and eleventh passages did not affect the viability, apoptotic classification, and ROS levels. Nevertheless, cells at seventh and eleventh passages featured a reduction in metabolism and an alteration in ΔΨm when compared to third passage cells. Additionally, cells at eleventh passage showed changes in the proliferative activity and morphology when compared to other passages. Regarding cryopreservation, no effect was observed on cryopreserved cells for morphology, viability, apoptotic classification, metabolism, and proliferative activity. Nevertheless, cryopreserved cells had alteration for ROS levels and ΔΨm. In summary, fibroblasts from northern tiger cat were affected by extended passage (seventh and eleventh passages) and cryopreservation. Adjustments to the in vitro culture and cryopreservation are necessary to reduce cellular oxidative stress caused by in vitro conditions.