Exosomes loaded with circPARD3 promotes EBV-miR-BART4-induced stemness and cisplatin resistance in nasopharyngeal carcinoma side population cells through the miR-579-3p/SIRT1/SSRP1 axis.
To explore the effects of exosomes loaded with circular RNA PARD3 on EBV-miR-BART4-induced stemness and resistance of cisplatin in nasopharyngeal carcinoma side population (NPC-SP) cells through the miR-579-3p/SIRT1/SSRP1 axis.
Sixty-five cancer tissues and 65 noncancerous tissues were collected from NPC patients or patients with rhinitis. The expressions of circPARD3, miR-579-3p, SIRT1, and SSRP1 were detected by qRT-PCR, western blot, or immunohistochemistry. In vivo tumor formation assay was performed in nude mice. Immunofluorescence and qRT-PCR were conducted for the determination of CD44 and CD133 expressions, and flow cytometry combined with Hoechst 33,342 dye efflux for identifying SP cells, CCK-8 and EdU assays for cell proliferation, and Transwell assay for migration and invasion.
CircPARD3, SIRT1, and SSRP1 were upregulated while miR-579-3p was downregulated in NPC tissues and cells. CircPARD3 was positively correlated with the expressions of SIRT1 and SSRP1, and miR-579-3p was negatively correlated with circPARD3, SIRT1, and SSRP1. Exosomes loaded with circPARD3 promoted EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells, while miR-579-3p reversed the effect of exosomal circPARD3 on EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells. Additionally, miR-579-3p suppressed EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells by regulating SIRT1. SIRT1 upregulated SSRP1 expression by catalyzing H3K4 methylation and down-regulation of SSRP1 reversed the effect of SIRT1 on EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells.
Exosomes loaded with circPARD3 promoted EBV-miR-BART4-induced stemness and cisplatin resistance in NPC-SP cells through the miR-579-3p/SIRT1/SSRP1 axis. Graphical Headlights • EBV-miR-BART4 induces the stemness and resistance of NPC-SP cells. • CircPARD3 regulates SIRT1 by miR-579-3p. • SIRT1 regulates SSRP1 expression by histone methylation. • Exosomes loaded with circPARD3 promotes EBV-miR-BART4-induced NPC-SP cell stemness and resistance by the miR-579-3p/SIRT1/SSRP1 axis.
Ai J
，Tan G
，Li W
，Liu H
，Li T
，Zhang G
，Zhou Z
，Gan Y
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Downregulation of EB virus miR-BART4 inhibits proliferation and aggressiveness while promoting radiosensitivity of nasopharyngeal carcinoma.
This study aims to explore the role of Epstein-Barr virus (EBV) miR-BART4 in occurrence and progression of nasopharyngeal carcinoma (NPC) and its effect on radiosensitivity.
The expressions of EBV and miR-BART4 in 108 cases of NPC tissues and 97 cases of chronic nasopharyngeal inflammation tissues were determined by real time quantitative polymerase chain reaction (PCR), and the relationship between the expression of miR-BART4 and the clinicopathological features of NPC was analyzed. Cell lines, HONEl, CNEl, CNE2, C666-1, 6-10B, and NP-69 were used to compare the expression of miR-BART4, in which the CNE2 cells were selected for further experiments. CNE2 cells were grouped into blank group, negative control (NC) group, miR-BART4 inhibitors group and miR-BART4 mimics group. Cells in above groups were under radiation of 6 Gy X ray for 12 h before grouped into control group, 6 Gy group, NC + 6 Gy group, miR-BART4 inhibitors + 6 Gy group and miR-BART4 mimics + 6 Gy group. Cell proliferation, clone formation ability, cell apoptosis, invasion and migration ability were measured by MTT assay, clone formation assay, flow cytometry (FCM), Transwell assay and scratch test, respectively. Western blot analysis was used to detect the expression of apoptosis-related proteins (cleaved caspase-3, Bax and Bcl-2) and epithelial-mesenchymal transition (EMT) marker protein E-cadherin and Vimentin. mRNA and protein expression of PTEN were detected by qRT-PCR and western blot. Bioinformatics software and luciferase activity experiments were used to verify the targeting relationship between miR-BART4 and PTEN.
Positive rate of EBV in NPC tissues (93.5%) was remarkably higher than that in chronic nasopharyngeal inflammation tissues (21.6%). miR-BART4 was highly expressed and mRNA and protein expression of PTEN was lowly expressed in EBV positive NPC tissues compared with EBV negative NPC tissues and chronic nasopharyngeal inflammation tissues. The expression of miR-BART4 was related to the clinical stage, lymph node metastasis and differentiation degree of NPC. Expression of miR-BART4 in CNE2, CNEl, HONEl, C666-1, 6-10B, 5-8F cells was higher than that in NP-69 cells. In CNE2 and C666-1 cell experiments, compared with blank group and NC group, miR-BART4 inhibitors group had decreased miR-BART4 expression, increased mRNA and protein expression of PTEN, cell survival rate, invasion and migration ability and increased cell apoptosis rate, which is totally contrary to the observation in miR-BART4 mimics group. The radiosensitive NPC tissues had higher miR-BART4 expression than that in radio-resistance NPC tissues. In comparison to 6 Gy group and NC + 6 Gy group, cell survival rate and clone number was inhibited, but the cell apoptosis rate was increased in miR-BART4 inhibitors +6 G group, in contrary to the observation in miR-BART4 inhibitors + 6 Gy group. Bioinformatics software and luciferase activity experiments confirmed that miR-BART4 could inhibit the expression of PTEN.
EBV may promote development and progression of NPC by up-regulating miR-BART4 expressions, consequently inhibiting its radiosensitivity, whose effect may be related to the targeting inhibition of PTEN expression.
Wu Q
，Han T
，Sheng X
，Zhang N
，Wang P
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Cinobufotalin powerfully reversed EBV-miR-BART22-induced cisplatin resistance via stimulating MAP2K4 to antagonize non-muscle myosin heavy chain IIA/glycogen synthase 3β/β-catenin signaling pathway.
Nasopharyngeal carcinoma (NPC) is an Epstein-Barr virus (EBV)-related tumor. The role of EBV-encoding miR-BART22 is still unclear in NPC. This study aimed to identify the detailed mechanisms by which EBV-miR-BART22 functions as a tumor-promoting factor and evaluate the action of cinobufotalin in treating EBV-miR-BART22-overexpressing NPC cells.
Using real-time PCR, western blotting, immunohistochemistry, and In situ hybridization, we detected the expression of miR-BART22 and MAP2K4 in tissues and cells, as well as evaluated their clinical relevance in NPC patients. The effects of miR-BART22 on cell metastasis, stemness and DDP chemoresistance were examined by sphere formation assay, side population analysis, transwell, boyden, in vivo xenograft tumor mouse model et al. Western blotting, immunofluorescence staining, luciferase reporter assay, ChIP, EMSA and Co-IP assay et al. were performed to explore the detailed molecular mechanism of EBV-miR-BART22 in NPC. Finally, we estimated the effects and molecular basis of Cinobufotalin on EBV-miR-BART22-overexpressing NPC cells in vitro and in vivo assays.
We observed that EBV-miR-BART22 not only promoted tumor stemness and metastasis, but also enhanced the resistance to Cisplatin (DDP) in vitro and in vivo. Mechanistic analysis indicated that EBV-miR-BART22 directly targeted the MAP2K4 and upregulated non-muscle myosin heavy chain IIA (MYH9) expression by PI3K/AKT/c-Jun-induced transcription. Further, MYH9 interacted with glycogen synthase 3β(GSK3β) protein and induced its ubiquitin degradation by activating PI3K/AKT/c-Jun-induced ubiquitin transcription and the latter combined with increased TRAF6 E3 ligase, which further bound to GSK3β protein. Reductions in the GSK3β protein thus promoted β-catenin expression and nuclear translocation, which induced tumor stemness and the epithelial-to-mesenchymal transition (EMT) signals. Furthermore, we observed that cinobufotalin, a new chemically synthesized compound, significantly suppressed EBV-miR-BART22-induced DDP chemoresistance by upregulating MAP2K4 to suppress MYH9/GSK3β/β-catenin and its downstream tumor stemness and EMT signals in NPC. Finally, clinical data revealed that increased miR-BART22 and reduced MAP2K4 expression caused the poor prognoses of NPC patients.
Our study provides a novel mechanism that cinobufotalin reversed the DDP chemoresistance and EMT induced by EBV-miR-BART22 in NPC.
Liu Y
，Jiang Q
，Liu X
，Lin X
，Tang Z
，Liu C
，Zhou J
，Zhao M
，Li X
，Cheng Z
，Li L
，Xie Y
，Liu Z
，Fang W
... -
《EBioMedicine》
MicroRNA-101-3p inhibits nasopharyngeal carcinoma cell proliferation and cisplatin resistance through ZIC5 down-regulation by targeting SOX2.
This study aims to explore the mechanism of microRNA (miR)-101-3p-mediated SOX2/ZIC5 axis in the progression of cisplatin resistance of nasopharyngeal carcinoma (NPC). ZIC5 expression was analyzed with a bioinformatics database and detected in NPC cell lines. Cisplatin-resistant cells (HNE-1/DDP and C666-1/DDP) were transfected with sh-ZIC5, sh-SOX2, sh-SOX2 + pcDNA3.1-ZIC5, or miR-101-3p Agomir + pcDNA3.1-SOX2. MiR-101-3p, SOX2, and ZIC5 expression was assessed after transfection, and cancer associated phenotypes were evaluated after cisplatin treatment. The potential relationships among miR-101-3p, SOX2, and ZIC5 were analyzed. A xenograft mouse model of NPC was established with HNE-1 cells stably transfected or not transfected with oe-ZIC5 and subjected to tail vein injection of miR-101-3p Agomir and intraperitoneal injection of cisplatin. Overexpression of ZIC5 was found in cisplatin-resistant NPC cells. Downregulating ZIC5 in NPC cells decreased cell viability, promoted apoptosis, and reduced cisplatin resistance. SOX2 had a binding site on ZIC5, and SOX2 promoted proliferation, migration, and cisplatin resistance and inhibited cell apoptosis by up-regulating ZIC5. Mechanistically, miR-101-3p was decreased in cisplatin-resistant NPC cells and negatively targeted SOX2. Overexpression of miR-101-3p inhibited tumor growth and cisplatin resistance in xenograft mouse model, which was reversed by ZIC5 overexpression. In conclusion, the miR-101-3p/SOX2/ZIC5 axis was implicated in cancer associated phenotypes and cisplatin resistance in NPC.
Li T
，Zhang G
，Li W
，Xiao J
，Zhou Z
，Tan G
，Ai J
... -
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ResearchGate
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钛学术
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