| Melanoma is characterized by high malignancy,rapid growth and poor prognosis.In recent years,its morbidity and mortality have risen sharply,causing widespread social attention.Radiotherapy is one of the main methods for the treatment of malignant tumors,and it is also the main treatment for advanced melanoma.However,treatment is often prone to increase the tolerance of radiotherapy,directly affecting the therapeutic effect of melanoma.How to reduce the radiation resistance of melanoma and study the related mechanisms,which are connected with the prognosis of patients and are of great significance for clinical treatment.MicroRNAs(miRNAs)are a class of small-molecule single-stranded RNAs that are widely found in eukaryotic organisms with a length of about 22 nucleotides.The classical function of miRNAs is to recognize and bind the target gene mRNA 3'-UTR through its seed sequence to inhibit the expression of its target gene.The study indicated that miRNA can regulate nearly one-third of human genes,and the gene regulation of miRNA is also a complex network-like structure.More and more studies have shown that miRNAs are closely related to tumor progression and play an important role in radiation therapy.Studies have shown that miR-615-3p can affect the occurrence and development of a variety of tumors,play a role in inhibiting tumors,but its role in melanoma and its mechanism remains unclear,and its effect on the efficacy of radiotherapy for melanoma has not been reported.Objective: To study the effect of miR-615-3p on the biological behavior of melanoma A375 cells and to explore the potential target genes of miR-615-3p.To study the role of miR-615-3p in the radiotherapy of melanoma cells and to explore the related molecular mechanism.Methods: Overexpression or inhibition of miR-615-3p expression in melanoma A375 cells,CCK-8 assay,RTCA assay and Colony formation assay for detecting A375 cell proliferation;a scratch wound healing assay for detecting cell migration;flow cytometry for detecting cell cycle.The target gene of miR-615-3p is predicted by Starbase database,and screened and verified by qRT-PCR and western blotting.MiR-615-3p were over-expressed or low-expressed in A375 cells after 48 h,then A375 cells were irradiated by 5 Gy X-rays.RTCA assay monitored cell proliferation in real time,and the expression of DNA damage-related and apoptosis-related proteins were detected by western blotting.Results: 1.After overexpression of miR-615-3p in A375 cells,the cell proliferation rate decreased,cell migration ability decreased,colony colony formation decreased,cell cycle arrest increased and mainly occurred in G1 phase;after lowexpression of miR-615-3p in A375 cells,cell proliferation rate and cell migration ability increased,colony colony formation increased,and cell cycle arrest decreased.2.The results of Starbase database prediction were verified.The results showed that SPIN1 protein may have a relationship with miR-615-3p.After overexpression of miR-615-3p,the mRNA and protein expression levels of SPIN1 were significantly decreased,while miR-615-3p was inhibited,caused an increase in the protein expression level of SPIN1.3.Overexpression of miR-615-3p in A375 cells were irradiated by X-ray,which resulted in a time-dependent decrease in cell proliferation,increased expression of DNA damage-associated protein ?H2AX,and increased expression of apoptosis-related proteins Bax and caspase-3.Lowexpression of miR-615-3p in A375 cells were irradiated by X-ray,which indicated the opposite resules.Conclusion: miR-615-3p can inhibit the proliferation,migration and clonal formation of melanoma A375 cells,and lead to cell cycle arrest;SPIN1 protein may be a potential target gene for miR-615-3p,miR-615-3p may affect cell proliferation by regulating the SPIN1 expression;miR-615-3p makes A375 cells more sensitive to radiotherapy,which can promote DNA damage and apoptosis induced by radiation. |
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