Causal role of immune cell phenotypes in idiopathic sudden sensorineural hearing loss: a bi-directional Mendelian randomization study.

Background: A growing body of evidence suggests that immunological processes have a significant role in developing idiopathic sudden sensorineural hearing loss (SSHL). However, few studies have examined the association between immune cell phenotype and SSHL using Mendelian Randomization (MR). Methods: The online genome-wide association studies (GWAS) database was used to compile data from GWAS covering 731 immunophenotypes and SSHL. Inverse variance weighted (IVW) analysis was primarily used for MR study, and single nucleotide polymorphisms (SNPs) associated with immunophenotypes served as dependent variables. A sensitivity study and the false discovery rate (FDR) correction were used to examine the MR hypothesis. In addition, the possibility of reverse causality between immunophenotype and SSHL was validated by reverse MR. Reverse MR was analyzed in a manner consistent with forward MR. Results: After FDR correction and sensitivity analysis, we screened 7 immunophenotypes, including IgD+ CD38dim %lymphocyte (95% CI: 1.0019, 1.0742, p = 3.87 × 10-2, FDR = 1.15 × 10-2); Unsw mem AC (95% CI: 1.004, 1.2522, p = 4.23 × 10-2, FDR = 2.25 × 10-2); CD86+ myeloid DC AC (95% CI: 1.0083, 1.1147, p = 2.24 × 10-2, FDR = 4.27 × 10-2); CD33dim HLA DR- AC (95% CI: 1.0046, 1.0583, p = 2.12 × 10-2, FDR = 4.69 × 10-2); SSC-A on CD8br (95% CI: 1.0028, 1.1461, p = 4.12 × 10-2, FDR = 4.71 × 10-2); CD45RA- CD4+ %T cell (95% CI: 1.0036, 1.0503, p = 2.32 × 10-2, FDR = 4.82 × 10-2); DP (CD4+CD8+) AC (95% CI: 1.011, 1.2091, p = 2.78 × 10-2, FDR = 4.97 × 10-2). There was a strong causal relationship with SSHL onset, and the reliability of the results was verified. Furthermore, the immunological cell profile and SSHL did not appear to be closely associated, as shown by reverse MR analysis. Conclusion: Our study provides more support for the current hypothesis that immunophenotypes and the pathophysiology of SSHL are closely associated. Further validation is needed to assess the role of these immunophenotypes in SSHL.

N6-Methyladenosine reader HNRNPC-mediated downregulation of circITCH prevents miR-224-3p sequestering and contributes to tumorigenesis in nasopharyngeal carcinoma.

BACKGROUND: N6-Methyladenosine (m6A) RNA methylation modulators are implicated in nasopharyngeal carcinoma (NPC). Circular RNAs (circRNAs) stimulate/inhibit the development of NPC by sponging microRNAs (miRNAs). Herein, m6A modifications affecting the circRNA/miRNA axis in NPC were explored. METHODS: Twenty prognostic m6A RNA methylation regulators were identified from 504 head/neck squamous cell carcinoma and 44 normal samples from The Cancer Genome Atlas (TCGA). Differentially expressed miRNAs were screened from the TCGA and Gene Expression Omnibus (GEO) databases. RNA-binding protein (RBP)-circRNA and circRNA-miRNA interactive pairs were verified using RBPmap and RNAhybrid, respectively. The RBP/circRNA/miRNA network was constructed using Cytoscape. Furthermore, CircITCH (hsa_circ_00059948), HNRNPC, and miR-224-3p expressions were detected by western blotting and quantitative polymerase chain reaction. The role of circITCH in NPC was examined using apoptosis, scratch wound healing, transwell invasion, and cell counting kit-8 assays. Finally, CircITCH-miR-224-3p and circITCH-HNRNPC interactions were assessed by dual-luciferase reporter and RNA-immunoprecipitation (RIP) assays, respectively. RESULTS: Bioinformatics analysis revealed that high pathological grade, late-stage tumors, and low survival were associated with increased HNRNPC expression. MiR-224-3p was upregulated in NPC and sequestered by circITCH. Construction of the RBP/circRNA/miRNA network highlighted the HNRNPC/circITCH/miR-224-3p axis. In vitro experiments demonstrated decreased circITCH expression and increased HNRNPC and miR-224-3p expressions in NPC. In NPC cells overexpressing circITCH, HNRNPC and miR-224-3p expressions were significantly decreased. Dual-luciferase assays demonstrated a targeting relationship between circITCH and miR-224-3p, and RIP assays demonstrated interaction of HNRNPC targets with circITCH. CONCLUSION: CircITCH overexpression inhibited NPC progression by sequestering miR-224-3p, and HNRNPC reduced circITCH expression through direct interaction.

Tumor suppressor functions of miRNA-375 in nasopharyngeal carcinoma through inhibition of ubiquitin-specific protease 1 expression.

BACKGROUND: Nasopharyngeal carcinoma (NPC) development involves many genetic alterations. This study profiled differentially expressed microRNAs (DE-miRNAs) and selected miR-375 for further study. METHODS: DE-miRNAs were screened using online databases and subjected to various analyzes. miR-375 mimics with negative control (NC) cDNA, and a ubiquitin-specific protease 1 (USP1) as well as a NC group were transfected into NPC cells for analysis by quantitative PCR, western blotting, wound healing, Transwell, flow cytometry, cell counting kit-8 (CCK-8), and luciferase gene reporter assays. RESULTS: Among these DE-miRNAs, miR-375 was downregulated and miR-21 was upregulated in NPC cells. Bioinformatical analysis identified USP1 as a potential target gene of miR-375. Increased USP1 expression was associated with poor survival of head and neck cancer patients. The luciferase assay confirmed miR-375 binding to the USP1 3'-untranslated region (UTR), while the transfection experiment confirmed miR-375 expression reduced USP1 expression. USP1 overexpression reversed the anti-tumor activity of miR-375 in NPC cells as determined by tumor cell migration, invasion, apoptosis, and viability assays. In addition, USP1 overexpression activated phosphoinositide 3-kinase (PI3K) signaling, whereas a selective PI3K inhibitor (S2739) could reverse the effects of USP1 on NPC cells in vitro. CONCLUSIONS: miR-375 and miR-21 are both related to NPC and miR-375 can target USP1. Further experiments revealed that up-regulated miR-375 expression led to USP1 down-regulation, and miR-375 overexpression suppressed PI3K/Akt signaling and inhibited NPC cell migration and invasion, but promoted NPC cell apoptosis.

Knockdown of hsa_circ_0023028 inhibits cell proliferation, migration, and invasion in laryngeal cancer by sponging miR-194-5p.

Emerging evidences have proposed that circular RNAs (circRNAs) play a major role in carcinogenesis. Hsa_circ_0023028 has been reported to be aberrantly expressed in laryngeal cancer (LCa). However, the role and the mechanism of hsa_circ_0023028 in LCa have not been adequately studied. In the present study, we demonstrated that hsa_circ_0023028 expression was up-regulated in LCa tissues and cell lines. miR-194-5p was down-regulated in LCa cells. Functionally, knockdown of hsa_circ_0023028 inhibited the proliferation, migration, and invasion of LCa cells, as evidenced by the reduced number of 5-Ethynyl-2'-deoxyuridine (EdU)-positive cells and decreased number of migrated and invaded cells. Additionally, hsa_circ_0023028 was identified as an miR-194-5p sink. A negative correlation between miR-194-5p and hsa_circ_0023028 expression was observed in LCa tissues. Besides, down-regulation of miR-194-5p attenuated the inhibitory effects of hsa_circ_0023028 silencing on LCa cell proliferation, migration, and invasion. In summary, hsa_circ_0023028 functions as an miR-194-5p sponge to promote the proliferation, migration, and invasion of LCa cells.

Frequent overexpression of PDK1 in primary nasopharyngeal carcinoma is associated with poor prognosis.

OBJECTIVE: Pyruvate dehydrogenase kinase 1 (PDK1) is reported to be up-regulated and play multiple functions in several cancers. Herein, we investigated its roles in primary nasopharyngeal carcinoma. METHODS: Expression of PDK1 protein was examined by immunohistochemical staining in 102 samples of primary nasopharyngeal carcinoma (pNPC) and 31 samples of chronic nasopharyngitis. The relationships of PDK1 expression levels with clinical features and prognosis in NPC patients were analyzed. RESULTS: PDK1 protein expression was significantly greater in pNPC tissues than in the chronic nasopharyngitis tissues (P<0.01). In addition, overexpression of PDK1 was associated with advanced clinical stage (P<0.01), advanced N classification (P=0.024), and distant metastasis (P=0.048). Kaplan-Meier survival analysis demonstrated that patients with higher PDK1 expression had significantly shorter overall survival (P=0.006), disease-free survival (P=0.015), loco-regional relapse-free survival (P=0.008), and distant metastasis-free survival (P=0.017). Furthermore, multi-variate analysis showed that PDK1 expression was an independent prognostic factor in pNPC patients. CONCLUSION: PDK1 is frequently upregulated in pNPC and may serve as a prognostic marker.