The long non-coding RNA nuclear paraspeckle assembly transcript 1 (NEAT1) was reported to be upregulated and be involved in oncogenic growth and drug resistance in nasopharyngeal carcinoma (NPC). However, the exact roles of NEAT1 and its underlying mechanisms in the drug resistance of NPC remain largely unclear. In this study, the expressions of NEAT1, let-72-5p and Rsf-1 mRNA were detected by reverse transcription-quantitative polymerase chain reaction (RT-qPCR). The effects of NEAT1 and let-72-5p on cell proliferation and cisplatin resistance of NPC cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and 5-ethynyl-20-deoxyuridine (EdU) assay. Western blot analysis was performed to detect the protein levels of Rsf-1, Ras, p-Raf1, Raf1, p-MEK1, MEK1, p-ERK1/2 and ERK1/2. Xenograft tumor assay was done to elucidate the role of NEAT1 involved in NPC tumor growth in vivo. We found that NEAT1 was upregulated and let-7a-5p was downregulated in NPC tissues, as well as NPC cell lines. Inhibition of NEAT1 markedly repressed the cisplatin resistance of NPC cells. NEAT1 was demonstrated to interact with let-7a-5p. Besides, a negative correlation between NEAT1 and let-7a-5p expression was observed in NPC tissues. Rsf-1 was confirmed as a target of let-7a-5p. NEAT1 remarkably reversed the inhibitory effect of let-7q-5p on the cisplatin resistance of NPC cells in vitro. Additionally, NEAT1 knockdown inhibited the Ras-MAPK pathway in NPC cells. NEAT1 knockdown suppressed tumor growth in the presence of cisplatin in vivo. Overall, these findings suggest that NEAT1/let-7a-5p axis regulates the cisplatin resistance in NPC by targeting Rsf-1 and modulating the Ras-MAPK signaling pathway.

Long noncoding RNAs (lncRNAs) play important roles in the initiation and progression of various cancers, including laryngeal squamous cell carcinoma (LSCC). Recently, lncRNA Sox2 overlapping transcript (SOX2‐OT) has been identified as an oncogene in various cancers. However, the functional role and the regulatory mechanism of SOX2‐OT in LSCC remains unclear. In this study, we found that SOX2‐OT expression was increased and negatively correlated with PTEN expression in LSCC tissues. Furthermore, SOX2‐OT overexpression promoted LSCC cell proliferation, migration, invasion, and suppressed cell apoptosis in vitro, as well as facilitated the in vivo tumorigenicity. By contrast, SOX2‐OT silencing exerted the opposite effect. Mechanically, SOX2‐OT interacted with EZH2 and recruited EZH2 to induce H3K27me3 and epigenetically inhibited PTEN expression in LSCC cells. Additionally, EZH2 silencing and PTEN overexpression significantly abrogated the SOX2‐OT overexpression‐mediated promotion of LSCC cell malignant behavior. Collectively, our findings demonstrate that SOX2‐OT inhibits PTEN expression to facilitate LSCC development through EZH2‐mediated H3K27me3. © 2019 IUBMB Life, 71(9):1230–1239, 2019

Treatment of frontal sinus using surgery is complicated owing to the complex anatomical structure of the sinus region. The aim of the present study was to investigate the efficacy and safety of Draf IIb endoscopic frontal sinus surgery treatment for frontal sinus lesions using the agger nasi approach on 19 patients (28 left or and right nasal cavities). A 10–12 mm excision of the upper frontal maxilla was performed for endoscopic resection between the middle turbinate and lateral nasal wall. No serious complications in frontal sinus surgery treatment for the removal of the frontal sinus were observed. Patients were followed up after surgery for 6–36 months. Chronic sinusitis and nasal polyps were identified in 10 cases (19 left or and right nasal cavities; disease control, 15 left or and right nasal cavities; and disease partial control, 4 left or and right nasal cavities). Frontal sinus inverted papilloma was observed in 9 cases (9 left or and right nasal cavities). Frontal sinus inverted papilloma were successfully treated in 8 cases, and 1 case of recurrence was observed. In conclusion, the nasal endoscopic Draf IIb agger nasi approach is a minimally invasive treatment for frontal sinus lesions. This surgical procedure is safe and less complicated and may be applied in the clinic.

No abstract