The novel circRNA circ_0045881 inhibits cell proliferation and invasion by targeting mir-214-3p in triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC) is the most lethal subtype of breast cancer (BC). The circRNA-miRNA‒mRNA axis is a promising biomarker for the early diagnosis and prognosis of BC. However, the critical circRNA mediators involved in TNBC progression and the underlying regulatory mechanism involved remain largely unclear. METHODS: In this study, we carried out a circRNA microarray analysis of 6 TNBC patients and performed a gene ontology (GO) analysis. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was used to characterize important circRNAs involved in TNBC progression. The interaction between circRNAs and miRNAs was determined by dual luciferase and RNA immunoprecipitation (RIP) assays. Moreover, Transwell, wound healing and Cell Counting Kit-8 (CCK8) assays were performed with altered circRNA or miRNA expression in MDA-MB-231 and BT-549 cells to investigate the roles of these genes in cell invasion, migration and proliferation. RESULTS: A total of 78 circRNAs were differentially expressed in TNBC tissues, and the hsa_circ_0045881 level was significantly decreased in TNBC tissues and cells. Lentivirus-mediated hsa_circ_0045881 overexpression in MDA-MB-231 and BT-549 cells significantly reduced cell invasion and migration capacity. Additionally, hsa_circ_0045881 interacted with miR-214-3p in MDA-MB-231 cells. miR-214-3p mimics in MDA-MB-231 and BT-549 cells significantly enhanced cell invasion, migration and proliferation, but the other combinations of inhibitors had opposite effects on cell activity. CONCLUSIONS: Our data indicated that the circRNA has_circ_0045881 plays key roles in TNBC progression and that hsa_circ_0045881 might act as a sponge for miR-214-3p to modulate its levels in TNBC cells, thereby regulating cell invasion, metastasis and proliferation. hsa_circ_004588 might be a potential prognostic marker and therapeutic target for TNBC.

CircRNA circSEPT9 Downregulates miR-10a through Methylation to Promote Cell Proliferation in Laryngeal Squamous Cell Carcinoma.

The oncogenic functions of circRNA circSEPT9 have been characterized in triple-negative breast cancer. We analyzed its role in laryngeal squamous cell carcinoma (LSCC). Quantitative reverse-transcription PCR (RT-qPCR) was used to analyze the expression of circSEPT9 and miR-10a in paired LSCC and nontumor tissues donated by 50 patients with LSCC. Methylation-specific PCR (MSP) was performed to analyze the role of circSEPT9 in miR-10a RNA gene methylation. circSEPT9 or miR-10a were overexpressed in LSCC cells to explore the interaction between them. The regulatory role of circSEPT9 and miR-10a in cell proliferation was studied with cell counting kit-8 (CCK-8) assay. CircSEPT9 was highly expressed in LSCC, whereas miR-10a was expressed at a lower level in LSCC. CircSEPT9 and miR-10a were closely correlated across LSCC tissue samples. In LSCC cells, circSEPT9 overexpression increased the methylation of the miR-10a gene and decreased the expression of miR-10a. CircSEPT9 overexpression increased LSCC cell proliferation, whereas miR-10a overexpression decreased cell proliferation. Co-transfection experiments showed that circSEPT9 overexpression attenuated the effects of miR-10a overexpression on cell proliferation. We conclude that circSEPT9 may increase miR-10a methylation to increase cell proliferation in LSCC.

P2Y2 promotes fibroblasts activation and skeletal muscle fibrosis through AKT, ERK, and PKC.

BACKGROUND: Skeletal muscle atrophy and fibrosis are pathological conditions that contribute to morbidity in numerous conditions including aging, cachexia, and denervation. Muscle atrophy is characterized as reduction of muscle fiber size and loss of muscle mass while muscle fibrosis is due to fibroblasts activation and excessive production of extracellular matrix. Purinergic receptor P2Y2 has been implicated in fibrosis. This study aims to elucidate the roles of P2Y2 in sleketal muscle atrophy and fibrosis. METHODS: Primary muscle fibroblasts were isolated from wild type and P2Y2 knockout (KO) mice and their proliferating and migrating abilities were assessed by CCK-8 and Transwell migration assays respectively. Fibroblasts were activated with TGF-ß1 and assessed by western blot of myofibroblast markers including α-SMA, CTGF, and collagen I. Muscle atrophy and fibrosis were induced by transection of distal sciatic nerve and assessed using Masson staining. RESULTS: P2Y2 KO fibroblasts proliferated and migrated significantly slower than WT fibroblasts with or without TGF-ß1.The proliferation and ECM production were enhanced by P2Y2 agonist PSB-1114 and inhibited by antagonist AR-C118925. TGF-ß1 induced fibrotic activation was abolished by P2Y2 ablation and inhibited by AKT, ERK, and PKC inhibitors. Ablation of P2Y2 reduced denervation induced muscle atrophy and fibrosis. CONCLUSIONS: P2Y2 is a promoter of skeletal muscle atrophy and activation of fibroblasts after muscle injury, which signaling through AKT, ERK and PKC. P2Y2 could be a potential intervention target after muscle injury.

Main branch of ACN-to-RLN for management of laryngospasm due to unilateral vocal cord paralysis.

OBJECTIVES/HYPOTHESIS: This study explored the feasibility and efficiency of main branch of ansa cervicalis nerve (ACN)-to-recurrent laryngeal nerve (RLN) anastomosis for management of paroxysmal laryngospasm due to unilateral vocal cord paralysis (UVCP). METHODS: Thirteen patients who underwent main branch of ACN-to-RLN anastomosis for management of paroxysmal laryngospasm due to UVCP were enrolled in the present study. Multidimensional assessments, including videostroboscopy, voice assessment, and laryngeal electromyography (LEMG), were performed preoperatively and postoperatively. RESULTS: This series was limited to UVCP with iatrogenic causes, including thyroidectomy, cervical spine surgery, and thoracic surgery. After main branch of ACN-to-RLN anastomosis, all cases showed significant airway improvement, and laryngospasm was completely abolished in 92.3% (12 of 13) of cases. Videostroboscopy showed that the bulging and paradoxical adduction of the affected vocal cord during a sniff were abolished immediately after operation, and there was no significant difference in vocal fold position or glottal closure before versus after the operation. LEMG showed that the postoperative recruitment and amplitude of voluntary motor unit potential in the affected thyroarytenoid muscle during a sniff were significantly decreased compared to preoperative values, and postoperative recruitment showed significant improvement during phonation compared to that preoperatively. Voice assessment showed that there were no significant differences in overall grade, roughness, breathiness, jitter (local), shimmer (local), noise-to-harmonics ratio, or maximum phonation time after the operation compared to the preoperative values. CONCLUSIONS: Main branch of ACN-to-RLN anastomosis could have long-lasting efficacy in the management of paroxysmal laryngospasm due to UVCP, with no apparent compromise of voice quality. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:2412-2419, 2020.