RESUMEN
PURPOSE: There is increasing evidence that non-coding RNAs (ncRNAs), including long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), produce a critical regulatory effect on osteosarcoma (OS). LINC01278, as a newly discovered lncRNA, is found to be highly expressed in OS, but its related mechanism remains unclear. This research, therefore, is designed to study the mechanism of LINC01278 in OS and to find potential targets for clinical use. METHODS: qRT-PCR was applied to determine the relative expression of LINC01278 and analyze its diagnostic value in OS. CCK-8, Transwell and flow cytometry were utilized for the determination of cell proliferation, migration/invasion, and apoptosis. RIP and RNA pull-down experiments were used to verify the targeted binding effect of miR-134-5p and LINC01278. The relationship between miR-134-5p and LINC01278 or KRAS was analyzed using dual luciferase reporter gene. The effects of LINC01278 on tumor growth in nude mice was analyzed by in vivo experiment. RESULTS: qRT-PCR showed that LINC01278 increased in OS tissues and serum, indicating poor prognosis. In addition, LINC01278 was also of high value for OS diagnosis. Functional experiments showed that LINC01278 inhibited KRAS-mediated OS cell proliferation and metastasis through miR-134-5p. Finally, the results of an in vivo animal model indicated that LINC01278 promoted OS growth. CONCLUSION: LINC01278 is expressed highly in OS, and patients with high LINC01278 expression have poor prognosis. Moreover, LINC01278 can suppress the proliferation and apoptosis of OS cells through mediating miR-134-5p/KRAS axis, which is expected to become a potential therapeutic target for OS.
RESUMEN
Euphorbia fischeriana Steud, a traditional Chinese medicine, has been shown to inhibit the growth of various cancers by the induction of apoptosis and cell cycle arrest. The purpose of the present study was to investigate the association between the phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) signaling pathway and the inhibitory effect of Euphorbia fischeriana Steud on the growth and metastasis of melanoma B16 cells in vitro, and the underlying mechanisms. MTT assay results indicated that Euphorbia fischeriana Steud inhibited the growth of B16 cells in a time- and dose-dependent manner. Flow cytometric analysis revealed that Euphorbia fischeriana Steud markedly induced apoptosis of the B16 cells, with arrest at the G0/G1 phase of the cell cycle. In addition, in a Transwell assay Euphorbia fischeriana Steud significantly suppressed the migration of B16 cells. Western blot analysis revealed that the expression levels of phosphatase and tensin homolog (PTEN) were upregulated, and the phosphorylation of Akt was downregulated, which resulted in inhibition of the PI3K/Akt signaling pathway and the eventual suppression of its downstream targets, such as matrix metalloproteinase-2 mRNA, in B16 cells. The results demonstrated that Euphorbia fischeriana Steud inhibited the growth and migration of B16 cells, possibly via modulation of the PI3K/Akt signaling pathway and upregulation of PTEN expression levels, in addition to downregulation of p-Akt expression. The aforementioned findings suggest that Euphorbia fischeriana Steud may have broad therapeutic applications in the treatment of malignant melanoma.
