KLF2 is a clinical diagnostic and treatment biomarker of breast cancer.

Background: As a highly prevalent malignancy among women worldwide, breast cancer, remains a critical public health issue necessitating the development of novel therapeutics and biomarkers. Kruppel Like Factor 2 (KLF2), a member of the Kruppel family of transcription factors, has been implicated in various types of cancer due to its diminished expression; however, the potential implications of KLF2 expression in relation to breast cancer progression, prognosis, and therapy remain unclear. Methods: The present study employed the Tumor Immune Estimation Resource (TIMER) and The Human Protein Atlas databases to investigate the expression pattern of KLF2 in pan-cancer. The relationship between KLF2 expression and clinical features or immune infiltration of The Cancer Genome Atlas (TCGA) breast cancer samples was evaluated using Breast Cancer Integrative Platform (BCIP) and TIMER. The expression levels of KLF2 in breast cancer were validated via immunohistochemical staining analysis. Gene Set Enrichment Analysis (GSEA) to study the KLF2-related gene ontology. STRING database was employed to construct a protein-protein interaction (PPI) network of KLF2 in relation to vascular endothelial growth factor A (VEGFA) and hypoxia-inducible factor 1α (HIF1α). The expression of KLF2 following diverse breast cancer therapies was analyzed in the Gene Expression Omnibus (GEO) databases. The expression of KLF2 following treatment with simvastatin was validated via immunofluorescence and western blotting. Results: Our study reveals that KLF2 displays significantly reduced expression in cancerous tissues compared to non-cancerous controls. Patients with low KLF2 expression levels exhibited poor prognosis across multiple cancer types. KLF2 expression levels were found to be reduced in advanced cancer stages and grades, while positively correlated with the expression of estrogen receptor (ER), progesterone receptor (PR), and tumor size in breast cancer. KLF2 expression is associated with diverse immune infiltration cells, and may impact the breast tumor immune microenvironment by regulating dendritic cell activation. Additionally, we observed a negative correlation between KLF2 expression levels and angiogenesis, as well as the expression of VEGFA and HIF1α. Notably, the anticancer drug simvastatin could induce KLF2 expression in both breast cancer. Conclusion: Based on our observations, KLF2 has potential as a diagnostic, prognostic, and therapeutic biomarker for breast cancer.

Rno_circRNA_006061 participates in apoptosis induced by formaldehyde via activating p38/ATF3 pathway.

Formaldehyde, a common indoor air pollutant, is significantly toxic to the respiratory system, whereas its mechanism is unclear. CircRNAs exert critical functions via sponging microRNAs (miRNAs). To evaluate the effect of long-term formaldehyde exposure on rno_circRNA_006061 expression profiles, the downstream targets and signaling pathways associated with rno_circRNA_006061 were predicted and validated using bioinformatics methods and dual-luciferase reporter assay. Previously, our circRNA microarray showed that rno_circRNA_006061 was up-regulated in the formaldehyde-exposed lung tissue. Subsequently, bioinformatics analysis predicted that rno_circRNA_006061 bound to rno-miR-128-3p and co-regulated the p38/ATF3 signaling pathway. Meanwhile, the expressions of rno_circRNA_006061, rno-miR-128-3p and p38 were correlated with the lung histomorphopathological injury assessment. Furthermore, TUNEL and Bax/Bcl-2 ratio results revealed that up-regulated rno_circRNA_00606 induced by formaldehyde stimulated apoptosis in the lung. After the knockdown of rno_circRNA_006061, the expression of rno-miR-128-3p increased and the expression of p38 decreased slightly, which partially restored formaldehyde-induced apoptosis in alveolar epithelial cells. In conclusion, our study hinted that the rno_circRNA_006061 might enhance p38/ATF3 pathway expression via sponging the rno-miR-128-3p, thus significantly promoting apoptosis in lung tissues, which may provide potential new targets for preventing and treating lung injury by formaldehyde inhalation.

Stable atrogin-1 (Fbxo32) and MuRF1 (Trim63) gene expression is involved in the protective mechanism in soleus muscle of hibernating Daurian ground squirrels (Spermophilus dauricus).

Understanding the mechanisms that protect against or limit muscle atrophy in hibernators during prolonged inactivity has important implications for its treatment. We examined whether external factors influence the pathways regulating protein synthesis and degradation, leading to muscle atrophy prevention in Daurian ground squirrels (Spermophilus dauricus). We investigated the effects of 14-day hindlimb-unloading (HU) in different seasons and two-month hibernation on the soleus (SOL) muscle wet mass, muscle-to-body mass ratio, fiber cross sectional area (CSA), fiber distribution and muscle ultrastructure. We also measured changes in the protein expression and activation states of Akt, mTOR and FoxO1 and the mRNA expression of atrogin-1 and MuRF1. Compared with the control groups, autumn and winter HU significantly lowered SOL muscle wet mass and muscle-to-body mass ratio, decreased type I and II fiber CSA and induced ultrastructural anomalies. However, these measured indices were unchanged between Pre-hibernation and Hibernation groups. Furthermore, phosphorylation levels of Akt and mTOR significantly decreased, while the phosphorylation level of FoxO1 and mRNA expression of atrogin-1 and MuRF1 increased after HU. During hibernation, the phosphorylation levels of Akt and mTOR significantly decreased, but the phosphorylation level of FoxO1 and mRNA expression of atrogin-1 and MuRF1 remained unchanged. Overall, our findings suggest that disuse and seasonality may not be sufficient to initiate the innate protective mechanism that prevents SOL atrophy during prolonged periods of hibernation inactivity. The stable expression of atrogin-1 and MuRF1 may facilitate to prevent SOL atrophy via controlling ubiquitination of muscle proteins during hibernation.