K homology-type splicing regulatory protein (KSRP) is emerging as a key player in cancer biology, and immunology. As a single-strand nucleic acid binding protein it functions in both transcriptional and post-transcriptional regulation, while facilitating multiple stages of RNA metabolism to affect proliferation and control cell fate. However, it must interact with other proteins to determine the fate of its bound substrate. Here we provide an minireview of this important regulatory protein and describe its complex subcellular functions to affect RNA metabolism, stability, miRNA biogenesis and maturation, stress granule function, metastasis, and inflammatory processes.
With the increasing aging population in China, the incidence rate of knee osteoarthritis is expected to rise annually. Therefore, we conducted a study to investigate the crucial role of LPCAT3 in osteoarthritis and its underlying mechanisms. We collected samples from normal volunteers (n = 12) and patients with osteoarthritis (n = 12) at our hospital. It was observed that LPCAT3 mRNA expression was reduced and positively correlated with IL-1β mRNA expression in patients with osteoarthritis. In a mouse model, LPCAT3 mRNA and protein expression were found to be suppressed. Furthermore, in an in vitro model, the enrichment level of LPCAT3 mRNA was inhibited by a specific m6A antibody through si-METTL3. Si-METTL3 also reduced the stability of LPCAT3 mRNA in the in vitro model. The inhibition of LPCAT3 was found to exacerbate osteoarthritis in the mouse model. Additionally, LPCAT3 was shown to reduce inflammation in the in vitro model. It was also observed that LPCAT3 reduced chondrocyte ferroptosis by inhibiting mitochondrial damage. LPCAT3 protein was found to interact with ACSL4 protein, and its up-regulation suppressed ACSL4 expression in the in vitro model. ACSL4 was identified as a target of LPCAT3 for suppressing mitochondrial damage in the in vitro model. In conclusion, this study demonstrates that LPCAT3 improves osteoarthritis by regulating ACSL4 to inhibit chondrocyte ferroptosis, thus providing a novel target for the treatment of osteoarthritis.
Histone acetylation that controlled by two mutually antagonistic enzyme families, histone acetyl transferases (HATs) and histone deacetylases (HDACs), as one of major epigenetic mechanisms controls transcription and its abnormal regulation was implicated in various aspects of cancer. However, the comprehensive understanding of HDACs and HATs in cancer is still lacking. Systematically analysis through 33 cancer types based on next-generation sequence data reveals heterogeneous expression pattern of HDACs and HATs across different cancer types. In particular, HDAC10 and HDAC6 show significant downregulation in most cancers. Principal components analysis (PCA) of pan-cancer reveals significant difference of HDACs and HATs between normal tissues and normal tissue adjacent to the tumor. The abnormal expression of HDACs and HATs was partially due to CNV and DNA methylation in multiple types of cancer. Prognostic significance (AUC reached 0.736) of HDACs and HATs demonstrates a five-gene signature including KAT2A, HAT1, KAT5, CREBBP and SIRT1 in KIRC. Analysis of NCI-60 drug database reveals the cytotoxic effect of several drugs are associated with dysregulated expression of HDACs and HATs. Analysis of immune infiltration and immunotherapy reveals that KAT2B and HDAC9 are associated with immune infiltration and immunotherapy. Our analysis provided comprehensive understanding of the regulation and implication of HDACs and HATs in pan-cancer. These findings provide novel evidence for biological investigating potential individual HDACs and HATs in the development and therapy of cancer in the future.
Bladder cancer (BC) is the second most common genitourinary malignancy. Long noncoding RNA (lncRNA) is implicated in BC progression. This study delved into the underlying mechanism of lncRNA MEG3 in BC. Bioinformatics analysis predicted the expression of lncRNA MEG3, its association with the survival of BC patients, its subcellular localization, and its binding sites with miR-21-5p. Differentially expressed genes (DEGs) in the GSE13507 chip were analyzed using GEOexplorer, downstream targets of miR-21-5p were predicted from databases, and the overlapping genes were analyzed by the website Venny2.1 (https://bioinfogp.cnb.csic.es/tools/venny/index.html); their impacts on patient survival were analyzed by the Starbase database. The expression of SPRY2 and TGFBI associated with patient survival was analyzed in TCGA. RT-qPCR and western blot were performed to detect levels of MEG3, miR-21-5p, and SPRY2 in BC/SV-HUC-1 cells. Malignant biological behaviors of BC cells were detected using CCK8, flow cytometry, and Transwell assays. RNA pull-down and dual-luciferase assays were employed to verify the binding relationship of miR-21-5p with MEG3 and SPRY2. MEG3 was found to be lowly expressed in BC cells and mainly distributed in the cytoplasm. Over-expression of MEG3 was found to inhibit BC cell activity, promote apoptosis, and reduce invasion and migration. miR-21-5p was found to be highly expressed in BC cells, and its down-regulation was found to inhibit the malignant behavior of BC cells. Over-expression of miR-21-5p was found to reverse the effect of pcDNA3.1-MEG3 on BC cells. MEG3 was found to competitively bind to miR-21-5p as a ceRNA to promote SPRY2 levels. LncRNA MEG3 promotes SPRY2 expression by competitively binding to miR-21-5p, thereby inhibiting proliferation and promoting apoptosis of BC cells.