MicroRNA-367-3p induces apoptosis and suppresses migration of MCF-7 cells by downregulating the expression of human choline kinase α

Dysregulated expression of miR‑367 in disease development and its prospects as a therapeutic target and diagnostic biomarker (Review)

MicroRNA (miR)-367 has a wide range of functions in gene regulation and as such plays a critical role in cell proliferation, differentiation and development, making it an essential molecule in various physiological processes. miR-367 belongs to the miR-302/367 cluster and is located in the intronic region of human chromosome 4 on the 4q25 locus. Dysregulation of miR-367 is associated with various disease conditions, including cancer, inflammation and cardiac conditions. Moreover, miR-367 has shown promise both as a tumor suppressor and a potential diagnostic biomarker for breast, gastric and prostate cancer. The elucidation of the essential role of miR-367 in inflammation, development and cardiac diseases emphasizes its versatility in regulating various physiological processes beyond cancer biology. However, further research is necessary to fully understand the complex regulatory mechanisms involving miR-367 in different physiological and pathological contexts. In conclusion, the versatility and significance of miR-367 makes it a promising candidate for further study and in the development of new diagnostic and therapeutic strategies.

Mesenchymal stem cell-derived exosomal microRNA-367–3p alleviates experimental autoimmune encephalomyelitis via inhibition of microglial ferroptosis by targeting EZH2

Multiple sclerosis (MS) is an autoimmune, inflammatory demyelinating disorder of the central nervous system. Accumulating evidence has underscored the therapeutic potential of bone marrow mesenchymal stem cells (BMSCs)-derived exosomes (BMSC-Exos) containing bioactive compounds in MS. Herein, the current study sought to characterize the mechanism of BMSC-Exos harboring miR-367-3p both in BV2 microglia by Erastin-induced ferroptosis and in experimental autoimmune encephalomyelitis (EAE), a typical animal model of MS. Exosomes were firstly isolated from BMSCs and identified for further use. BV2 microglia were co-cultured with miR-367-3p-containing BMSC-Exos, followed by an assessment of cell ferroptosis. Mechanistic exploration was furthered by the interaction of miR-367-3p and its downstream regulators. Lastly, BMSC-Exos harboring miR-367-3p were injected into EAE mice for in vivo validation. BMSC-Exos carrying miR-367-3p restrained microglial ferroptosis in vitro. Mechanistically, miR-367-3p could bind to Enhancer of zeste homolog 2 (EZH2) and restrain EZH2 expression, leading to the over-expression of solute carrier family 7 member 11 (SLC7A11). Meanwhile, over-expression of SLC7A11 resulted in Glutathione Peroxidase 4 (GPX4) activation and ferroptosis suppression. Ectopic expression of EZH2 in vitro negated the protective effects of BMSC-Exos. Furthermore, BMSC-Exos containing miR-367-3p relieved the severity of EAE by suppressing ferroptosis and restraining EZH2 expression in vivo. Collectively, our findings suggest that BMSC-Exos carrying miR-367-3p brings about a significant decline in microglia ferroptosis by repressing EZH2 and alleviating the severity of EAE in vivo, suggesting a possible role of miR-367-3p overexpression in the treatment strategy of EAE. AVAILABILITY OF DATA AND MATERIALS: The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

DHRS2 inhibits cell growth and metastasis in ovarian cancer by downregulation of CHKα to disrupt choline metabolism

The short-chain dehydrogenase/reductase (SDR) superfamily has essential roles in lipid metabolism and redox sensing. In recent years, accumulating evidence highlights the emerging association between SDR family enzymes and cancer. Dehydrogenase/reductase member 2(DHRS2) belongs to the NADH/NADPH-dependent SDR family, and extensively participates in the regulation of the proliferation, migration, and chemoresistance of cancer cells. However, the underlying mechanism has not been well defined. In the present study, we have demonstrated that DHRS2 inhibits the growth and metastasis of ovarian cancer (OC) cells in vitro and in vivo. Mechanistically, the combination of transcriptome and metabolome reveals an interruption of choline metabolism by DHRS2. DHRS2 post-transcriptionally downregulates choline kinase α (CHKα) to inhibit AKT signaling activation and reduce phosphorylcholine (PC)/glycerophosphorylcholine (GPC) ratio, impeding choline metabolism reprogramming in OC. These actions mainly account for the tumor-suppressive role of DHRS2 in OC. Overall, our findings establish the mechanistic connection among metabolic enzymes, metabolites, and the malignant phenotype of cancer cells. This could result in further development of novel pharmacological tools against OC by the induction of DHRS2 to disrupt the choline metabolic pathway.

DNA Methylation of Human Choline Kinase Alpha Promoter-Associated CpG Islands in MCF-7 Cells

Choline kinase (CK) is the enzyme catalyzing the first reaction in CDP-choline pathway for the biosynthesis of phosphatidylcholine. Higher expression of the α isozyme of CK has been implicated in carcinogenesis, and inhibition or downregulation of CKα (CHKA) is a promising anticancer approach. This study aimed to investigate the regulation of CKα expression by DNA methylation of the CpG islands found on the promoter of this gene in MCF-7 cells. Four CpG islands have been predicted in the 2000 bp promoter region of ckα (chka) gene. Six CpG island deletion mutants were constructed using PCR site-directed mutagenesis method and cloned into pGL4.10 vectors for promoter activity assays. Deletion of CpG4C region located between -225 and -56 significantly increased the promoter activity by 4-fold, indicating the presence of important repressive transcription factor binding site. The promoter activity of methylated full-length promoter was significantly lower than the methylated CpG4C deletion mutant by 16-fold. The results show that DNA methylation of CpG4C promotes the binding of the transcription factor that suppresses the promoter activity. Electrophoretic mobility shift assay analysis showed that cytosine methylation at MZF1 binding site in CpG4C increased the binding of putative MZF1 in nuclear extract. In conclusion, the results suggest that DNA methylation decreased the promoter activity by promoting the binding of putative MZF1 transcription factor at CpG4C region of the ckα gene promoter.

Choline Kinase: An Unexpected Journey for a Precision Medicine Strategy in Human Diseases

Choline kinase (ChoK) is a cytosolic enzyme that catalyzes the phosphorylation of choline to form phosphorylcholine (PCho) in the presence of ATP and magnesium. ChoK is required for the synthesis of key membrane phospholipids and is involved in malignant transformation in a large variety of human tumours. Active compounds against ChoK have been identified and proposed as antitumor agents. The ChoK inhibitory and antiproliferative activities of symmetrical bispyridinium and bisquinolinium compounds have been defined using quantitative structure-activity relationships (QSARs) and structural parameters. The design strategy followed in the development of the most active molecules is presented. The selective anticancer activity of these structures is also described. One promising anticancer compound has even entered clinical trials. Recently, ChoKα inhibitors have also been proposed as a novel therapeutic approach against parasites, rheumatoid arthritis, inflammatory processes, and pathogenic bacteria. The evidence for ChoKα as a novel drug target for approaches in precision medicine is discussed.