Circ_0062270 upregulates EPHA2 to facilitate melanoma progression via sponging miR-331-3p

Upregulation of EphA2 is associated with apoptosis in response to H2O2 and UV radiation-induced cataracts

In this article, we examine the role of erythropoietin-producing hepatocellular receptor A2 (EphA2) in the apoptosis of lens epithelial cells (LECs) in H2O2 and UV radiation-induced cataracts. We treated SRA01/04 cells with H2O2 or ultraviolet (UV) radiation to create a cataract cell model. We constructed a cataract lens model by exposing mice to UV radiation. We used CCK8 assays, Annexin V-FITC analysis, and immunohistochemical staining to explore proliferation and apoptosis of the cataract model. Thereafter, we used quantitative real-time PCR (qPCR) analysis, Western blot assays, and immunofluorescence to determine gene and protein expression levels. We also employed Crispr/Cas9 gene editing to create an EphA2 knockout in SRA01/04 cells. Results: H2O2 or UV radiation induced SRA01/04 cells showed EphA2 gene upregulation. CCK8 and apoptosis assays showed that EphA2 over-expression (OE) reduced epithelial cell apoptosis, but knockout of EphA2 induced it in response to H2O2 and UV radiation, respectively. Mutation of the EphA2 protein kinase domain (c.2003G > A, p. G668D) had a limited effect on cell apoptosis. In vivo, the EphA2 protein level increased in the lenses of UV-treated mice. Our results showed that EphA2 was upregulated in SRA01/04 cells in response to H2O2 and UV radiation. Mutation of the EphA2 protein kinase domain (c.2003G > A, p. G668D) had a limited effect on H2O2 and UV radiation-induced cell apoptosis. We confirmed this change with an experiment on UV-treated mice. The present study established a novel association between EphA2 and LEC apoptosis.

Circ_0081054 facilitates melanoma development via sponging miR-637 and regulating RAB9A

BACKGROUND

Accumulating evidence announces that aberrantly expressed circRNAs were closely related to the development of human cancers. However, the role and mechanism of multiple circRNAs remain unclear. Our work aimed to disclose the functional role and mechanism of circ_0081054 in melanoma.

METHODS

Quantitative real-time polymerase chain reaction assay was utilized to detect circ_0081054, microRNA-637 (miR-637) and RAB9A (member RAS oncogene family) mRNA expression. Cell proliferative ability was evaluated via Cell Counting Kit-8 and colony formation assay. Cell invasion was assessed by using wound healing assay.

RESULTS

The significant upregulation of circ_0081054 was detected in melanoma tissues and cells. The proliferation, migration, glycolytic metabolism, and angiogenesis in melanoma cells were suppressed, while apoptosis was promoted following the silence of circ_0081054. In addition, circ_0081054 could target miR-637, and miR-637 inhibitor could reverse the effects of circ_0081054 deficiency. Furthermore, RAB9A was a target gene for miR-637 and RAB9A overexpression could reverse the effects of miR-637 overexpression. In addition, the deficiency of circ_0081054 hampered tumor growth in vivo. Moreover, circ_0081054 could regulate RAB9A expression by sponging miR-637.

CONCLUSION

All results indicated that circ_0081054 promoted the malignant behaviors of melanoma cells partly by regulating the miR-637/RAB9A molecular axis.

Hsa_circ_0103232 promotes melanoma cells proliferation and invasion via targeting miR-661/RAB3D

Little is known about the role of hsa_circ_0103232 in melanoma. This study researched the role of hsa_circ_0103232 in melanoma progression. Hsa_circ_0103232 expression in clinical tissues of melanoma patients and melanoma cells was detected by qRT-PCR. Hsa_circ_0103232 localization in melanoma cells was visualized by fluorescence in situ hybridization. Hsa_circ_0103232 effect on melanoma cells viability, proliferation, migration, and invasion was explored by cell counting kit-8 (CCK-8) assay, Edu experiment, wound healing assay, and Transwell experiment. RNA pull-down assay and dual-luciferase reporter gene assay were performed to verify the binding of hsa_circ_0103232 with miR-661, and the binding of miR-661 and RAB3D. Xenograft tumor models were constructed. Western blot and immunohistochemistry were used for protein expression detection. Hsa_circ_0103232 expression was increased in melanoma patients, indicating lower overall survival. Hsa_circ_0103232 was mainly expressed in the cytoplasm of melanoma cells. Silencing hsa_circ_0103232 suppressed melanoma cell viability, proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) (P < 0.01). Hsa_circ_0103232 functioned as a sponge of miR-661 to increase RAB3D expression. miR-661 overexpression partially reversed hsa_circ_0103232 promoting effect on melanoma cells viability, proliferation, migration, invasion, and EMT (P < 0.01). In melanoma patients, hsa_circ_0103232 expression was negatively correlated with miR-661 and positively correlated with RAB3D. Silencing hsa_circ_0103232 suppressed melanoma cell growth in vivo and Ki67 and RAB3D expression in xenograft tumors (P < 0.01). Hsa_circ_0103232 is a tumor promoter in melanoma to enhance malignant phenotype and growth in vivo via sponging miR-661/RAB3D. Hsa_circ_0103232 may be a novel target for melanoma treatment.