Hsa_circ_0000345 inhibits cell proliferation, migration and invasion of nasopharyngeal carcinoma cells via miR-513a-3p/PTEN axis

Abstract

Background: Hsa_circ_0000345 has been reported to be down-regulated in nasopharyngeal carcinoma (NPC). Whether hsa_circ_0000345 can exert antitumor effect in NPC remains unclear. This study aimed to investigate the possible biological role of hsa_cic_0000345 in suppressing the progression of NPC.

Methods: Hsa_circ_0000345 expression was detected in normal nasopharynx epithelial cells (NP69) and NPC cell lines (SUNE1, HONE1, 6-10B and HNE1). The influence of hsa_circ_0000345 on cell proliferation, migration and invasion of NPC cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and transwell assays. Quantitative real-time PCR and western blot were performed to examine gene and protein expression, respectively. Luciferase reporter assay was carried out to verify the relationship among hsa_circ_0000345, miR-513a-3p and phosphatase and tensin homolog deleted on chromosome 10 (PTEN).

Results: Compared with NP69 cells, hsa_circ_0000345 was down-regulated in NPC cells. Moreover, hsa_circ_0000345 overexpression repressed cell proliferation, migration and invasion of SUNE1 cells, whereas hsa_circ_0000345 knockdown promoted cell proliferation, migration and invasion of 6-10B cells. Furthermore, hsa_circ_0000345 promoted PTEN expression by sponging miR-513a-3p. Both miR-513a-3p overexpression and PTEN knockdown promoted cell proliferation, migration and invasion of SUNE1 cells, which were effectively abolished by hsa_circ_0000345 up-regulation.

Conclusion: Hsa_circ_0000345 inhibits cell proliferation, migration and invasion of NPC cells via miR-513a-3p/PTEN axis, thereby suppressing the progression of NPC. Thus, this work suggests that hsa_circ_0000345 may be a potential biomarker for diagnosis and treatment of NPC.

Keywords: Hsa_circ_0000345; Invasion; Migration; Nasopharyngeal carcinoma; PTEN; Proliferation; miR-513a-3p.

Fig. 1

Hsa_circ_0000345 overexpression repressed cell proliferation, migration and invasion of SUNE1 cells, and hsa_circ_0000345 knockdown promoted cell proliferation, migration and invasion of 6-10B cells. A QRT-PCR was performed to detect the expression of hsa_circ_0000345 in NP69, SUNE1, HONE1, 6-10B and HNE1 cells. SUNE1 cells were transfected with pcDNA3.1-hsa_circ_0000345 or pcDNA3.1-NC. 6-10B cells were transfected with Si-hsa_circ_0000345 or Si-NC. B, C QRT-PCR was performed to assess the expression of hsa_circ_0000345 in the transfected SUNE1 and 6-10B cells. D, E MTT assay was performed to examine cell proliferation of the transfected SUNE1 and 6-10B cells. (F-K) Transwell assay was performed to estimate cell migration and invasion of the transfected SUNE1 and 6-10B cells. **P < 0.01 vs. NP69; ^##P < 0.01 vs. Vector; ^$$P < 0.01 vs. Si-NC

Fig. 2

Hsa_circ_0000345 interacted with miR-513a-3p, and miR-513a-3p interacted with PTEN. A, B Luciferase reporter assay was performed to determine the relationship among hsa_circ_0000345, miR-513a-3p and PTEN in 293 T cells. **P < 0.01 vs. mimic NC

Fig. 3

Hsa_circ_0000345 promoted PTEN expression by repressing miR-513a-3p. SUNE1 cells were co-transfected with pcDNA3.1-hsa_circ_0000345 or pcDNA3.1-NC and miR-513a-3p mimic or mimic NC. A QRT-PCR was performed to assess the expression of miR-513a-3p and PTEN in the transfected SUNE1 cells. B WB was performed to examine the expression of PTEN in the transfected SUNE1 cells. 6-10B cells were transfected with Si-hsa_circ_0000345 or Si-NC and miR-513a-3p inhibitor or inhibitor NC. C QRT-PCR was performed to assess the expression of miR-513a-3p and PTEN in the transfected 6-10B cells. D WB was performed to examine the expression of PTEN in the transfected 6-10B cells. **P < 0.01 vs. Vector + mimic NC; ^##P < 0.01 vs. Vector + miR-513a-3p mimic; ^$$P < 0.01 vs. Si-NC + inhibitor NC; ^&&P < 0.01 vs. Si-NC + miR-513a-3p inhibitor

Fig. 4

Hsa_circ_0000345 repressed cell proliferation, migration and invasion of SUNE1 cells by repressing miR-513a-3p. SUNE1 cells were co-transfected with pcDNA3.1-hsa_circ_0000345 or pcDNA3.1-NC and miR-513a-3p mimic or mimic NC. A MTT assay was performed to examine cell proliferation of the transfected SUNE1 cells. B, C Transwell assay was performed to estimate cell migration and invasion of the transfected SUNE1 cells. **P < 0.01 vs. Vector + mimic NC; ^##P < 0.01 vs. Vector + miR-513a-3p mimic

Fig. 5

Hsa_circ_0000345 repressed cell proliferation, migration and invasion of SUNE1 cells by promoting PTEN. SUNE1 cells were co-transfected with pcDNA3.1-hsa_circ_0000345 or pcDNA3.1-NC and Si-PTEN or Si-NC. A MTT assay was performed to examine cell proliferation of the transfected SUNE1 cells. B, C Transwell assay was performed to estimate cell migration and invasion of the transfected SUNE1 cells. **P < 0.01 vs. Vector + Si-NC; ^##P < 0.01 vs. Vector + Si-PTEN