HIF-1-Induced hsa-miR-429: Understanding Its Direct Targets as the Key to Developing Cancer Diagnostics and Therapies

Regulation of TGF-β2-induced epithelial-mesenchymal transition and autophagy in lens epithelial cells by the miR-492/NPM1 axis

A cataract is a clinically common blinding disease closely related to the ageing of the eye cells, which has become a major health killer in the elderly. Our research seeks to analyze the primary targets linked to the pathogenesis of cataracts during the ageing process. We performed bioinformatics analyses on the GSE101727 dataset to discover genes linked with ageing and cataracts. To explore the impacts of Nucleophosmin 1 (NPM1) on cell apoptosis, proliferation, as well as epithelial-mesenchymal transition (EMT) processes, in vitro tests such as western blotting, flow cytometry, and MTT were carried out. Additionally, the study incorporated transforming growth factor β2 (TGF-β2) to examine its function in cellular responses, chloroquine (CQ) to regulate autophagic flow, and H2O2 therapy to mimic oxidative stress. Our study discovered seven ageing-related genes, including NPM1, that had substantial relationships with cataracts. NPM1 overexpression was shown to boost cell proliferation and prevent apoptosis in SRA01/04 cells. Notably, NPM1 modulated the TGF-β signalling pathway, influencing cell proliferation and EMT processes. miR-429 was shown to be adversely regulating NPM1 and autophagy-related proteins, as demonstrated by changes in their expression in response to TGF-β2 treatment. Furthermore, NPM1 knockdown restored autophagy activity suppressed by miR-429 mimics, indicating a complex interaction of miR-429, NPM1, and TGF-β2 pathways in regulating autophagy and EMT. Lens epithelial cell proliferation and apoptosis were largely regulated by NPM1, as well as autophagy and EMT, which were significantly mediated by TGF-β2 and the miR-429/NPM1 axis. These results imply new possible targets for prognosis and therapy of cataracts.

Prognostic value and potential regulatory relationship of miR-200c-5p in colorectal cancer

This study aimed to investigate the relationship and potential mechanisms of miR-200c-5p in colorectal cancer (CRC) progression. Differentially expressed miRNAs were screened using the TCGA database. Subsequently, univariate analysis was performed to identify CRC survival-related miRNAs. Survival and receiver operator characteristic curves were generated. The target genes of miR-200c-5p and the relevant signaling pathways or biological processes were predicted by the miRNet database and enrichment analyses. The miR-200c-5p expression was detected using quantitative reverse-transcription polymerase chain reaction, Cell Counting Kit-8, Transwell, and cell apoptosis experiments were performed to determine miR-200c-5p's impact on CRC cell viability, invasiveness, and apoptosis. Finally, we constructed a CRC mouse model with inhibited miR-200c-5p to evaluate its impact on tumors. miR-200c-5p was upregulated in CRC, implying a favorable prognosis. Gene set enrichment analysis revealed that miR-200c-5p may participate in signaling pathways such as the TGF-β signaling pathway, RIG-I-like receptor signaling pathway, renin-angiotensin system, and DNA replication. miR-200c-5p potentially targeted mRNAs, including KCNE4 and CYP1B1, exhibiting a negative correlation with their expression. Furthermore, these mRNAs may participate in biological processes like the regulation of intracellular transport, cAMP-dependent protein kinase regulatory activity, ubiquitin protein ligase binding, MHC class II protein complex binding, and regulation of apoptotic signaling pathway. Lastly, miR-200c-5p overexpression repressed the viability and invasiveness of CRC cells but promoted apoptosis. The tumor size, weight, and volume were significantly increased by inhibiting miR-200c-5p (p < 0.05). miR-200c-5p is upregulated in CRC, serving as a promising biomarker for predicting CRC prognosis.

Regulation of the HIF switch in human endothelial and cancer cells

Hypoxia-inducible factors (HIFs) are transcription factors that reprogram the transcriptome for cells to survive hypoxic insults and oxidative stress. They are important during embryonic development and reprogram the cells to utilize glycolysis when the oxygen levels are extremely low. This metabolic change facilitates normal cell survival as well as cancer cell survival. The key feature in survival is the transition between acute hypoxia and chronic hypoxia, and this is regulated by the transition between HIF-1 expression and HIF-2/HIF-3 expression. This transition is observed in many human cancers and endothelial cells and referred to as the HIF Switch. Here we discuss the mechanisms involved in the HIF Switch in human endothelial and cancer cells which include mRNA and protein levels of the alpha chains of the HIFs. A major continuing effort in this field is directed towards determining the differences between normal and tumor cell utilization of this important pathway, and how this could lead to potential therapeutic approaches.

Understanding the Significance of Hypoxia-Inducible Factors (HIFs) in Glioblastoma: A Systematic Review

BACKGROUND

The study aims to investigate the role of hypoxia-inducible factors (HIFs) in the development, progression, and therapeutic potential of glioblastomas.

METHODOLOGY

The study, following PRISMA guidelines, systematically examined hypoxia and HIFs in glioblastoma using MEDLINE (PubMed), Web of Science, and Scopus. A total of 104 relevant studies underwent data extraction.

RESULTS

Among the 104 studies, global contributions were diverse, with China leading at 23.1%. The most productive year was 2019, accounting for 11.5%. Hypoxia-inducible factor 1 alpha (HIF1α) was frequently studied, followed by hypoxia-inducible factor 2 alpha (HIF2α), osteopontin, and cavolin-1. Commonly associated factors and pathways include glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3) receptors, vascular endothelial growth factor (VEGF), phosphoinositide 3-kinase (PI3K)-Akt-mechanistic target of rapamycin (mTOR) pathway, and reactive oxygen species (ROS). HIF expression correlates with various glioblastoma hallmarks, including progression, survival, neovascularization, glucose metabolism, migration, and invasion.

CONCLUSION

Overcoming challenges such as treatment resistance and the absence of biomarkers is critical for the effective integration of HIF-related therapies into the treatment of glioblastoma with the aim of optimizing patient outcomes.

The Unfolded Protein Response: A Double-Edged Sword for Brain Health

Efficient brain function requires as much as 20% of the total oxygen intake to support normal neuronal cell function. This level of oxygen usage, however, leads to the generation of free radicals, and thus can lead to oxidative stress and potentially to age-related cognitive decay and even neurodegenerative diseases. The regulation of this system requires a complex monitoring network to maintain proper oxygen homeostasis. Furthermore, the high content of mitochondria in the brain has elevated glucose demands, and thus requires a normal redox balance. Maintaining this is mediated by adaptive stress response pathways that permit cells to survive oxidative stress and to minimize cellular damage. These stress pathways rely on the proper function of the endoplasmic reticulum (ER) and the activation of the unfolded protein response (UPR), a cellular pathway responsible for normal ER function and cell survival. Interestingly, the UPR has two opposing signaling pathways, one that promotes cell survival and one that induces apoptosis. In this narrative review, we discuss the opposing roles of the UPR signaling pathways and how a better understanding of these stress pathways could potentially allow for the development of effective strategies to prevent age-related cognitive decay as well as treat neurodegenerative diseases.