RESUMEN
BACKGROUND: Circular RNA RHOT1 (circRHOT1) plays crucial roles in tumorigenesis by competing with microRNAs. It is largely abundant in tumor cell-derived exosomes. Meanwhile, cancer-derived exosomes participate in diverse biological processes. However, the expression patterns and functions of exosomal circRHOT1 in breast cancer remain unknown. This study is aimed to investigate and elucidate the exosomal circRHOT1/miR-204-5p/PRMT5 axis in breast cancer. METHODS: The exosomes derived from serum samples of breast cancer patients and breast cancer cell lines were characterized using transmission electron microscopy and Western blot. MTT, colony formation, wound healing, and transwell assays were utilized to analyze cell proliferation, migration, and invasion of breast cancer cells. Flow cytometry was used for apoptosis analysis. The bioinformatics method was employed to screen differentially expressed novel circRNAs and predict the microRNA targets of circRHOT1. Dual-luciferase reporter gene assays were performed to verify their direct interaction. Finally, Xenograft experiments were used to investigate the effect of exosomal circRHOT1 on tumor growth in vivo. RESULTS: CircRHOT1 exhibited significantly high expression in exosomes derived from the serum of breast cancer patients and breast cancer cell lines, which suggested its potential diagnostic value. Breast cancer-derived exosomes promoted the cell proliferation, migration, invasion, and epithelial-mesenchymal transition of breast cancer cells while inhibiting apoptosis. However, exosomes with downregulated circRHOT1 inhibited the growth of co-cultured cells. Mechanistically, circRHOT1 acted as a sponge of miR-204-5p and promoted protein arginine methyltransferase 5 (PRMT5) expression. Moreover, miR-204-5p inhibitor and pcPRMT5 could reverse the tumor suppressive effects mediated by circRHOT1-knockdown. Furthermore, treatment with exosomes derived from breast cancer cells with circRHOT1 knockdown attenuated tumor growth in tumor-bearing nude mice, which was accompanied by a reduction in PRMT5 expression and an enhancement of miR-204-5p expression. CONCLUSION: The exosomal circRHOT1 may promote breast cancer progression by regulating the miR-204-5p/PRMT5 axis. The current study strengthens the role of circRHOT1, miR-204-5p, and PRMT5 in breast cancer development and provides a potential treatment strategy for breast cancer.
RESUMEN
The present study explored the effective components, functional targets, and mechanism of Sparganii Rhizoma(vinegar-processed Sparganii Rhizoma) in the treatment of hyperlipidemia based on network pharmacology and experimental verification. In the network pharmacology, the screening of active components, target prediction, and pathway enrichment analysis of Sparganii Rhizoma were carried out, followed by the comparison with targets and pathways related to hyperlipidemia. In the experimental verification, the hyperlipidemia model in rats was induced to detect hemorheological parameters and coagulation function. The liver index was observed by HE staining, and PCR technology was used to verify the results of the network pharmacological analysis. Compared with the model group, the Sparganii Rhizoma and vinegar-processed Sparganii Rhizoma groups showed decreased liver index(P<0.05), reduced liver lipid deposition, dwindled serum low-density lipoprotein cholesterol(LDL-c) level(P<0.05), diminished blood viscosity, and increased prothrombin time(PT), thrombin time(TT), and activated partial thrombin time(APTT)(P<0.05). As revealed by the PCR assay, Sparganii Rhizoma could affect LDL-c and high-density lipoprotein cholesterol(HDL-c) levels and reduce the inhibitory effect of cholesterol ester transporter by regulating the expression of Apol2, Apof, and Stab2, thereby treating hyperlipidemia. Vinegar-processed Sparganii Rhizoma could enhance triglyceride metabolism and cholesterol reversal by regulating the expression of Hmgcr, Hmgcs2, Abca1, Abcg1, Cyp7 b1, and Stab2. Compared with the Sparganii Rhizoma, the vinegar-processed one was potent in treating hyperlipidemia. The active components of Sparganii Rhizoma in the treatment of hyperlipidemia may be L-alpha-palmitin,(1S,2S)-1,2-bis(2-furyl)ethane-1,2-diol, cis-zimtsaeure, o-acetyl-p-cresol, sanleng, and 9-hexadecenoic acid. Based on the network pharmacology and experimental verification, this study preliminarily explored the potential active components and possible mechanism of Sparganii Rhizoma in the treatment of hyperlipidemia, which is expected to provide a certain basis for in-depth research on active components, mechanism, and clinical application.