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Objective:To investigate the effect of LINC00261 on the radiosensitivity of nasopharyngeal carcinoma and tumor formation and its underlying mechanism in nude mice.Methods:qRT-PCR was used to detect the relative expression levels of miR-620 and LINC00261 in radiosensitive and radioresistant nasopharyngeal carcinoma tissues. After the 6-10B and HNE-3 cells were irradiated with 0, 2, 4, 6, and 8 Gy 60Coγ-ray, the relative expression levels of miR-620 and LINC00261 were measured by qRT-PCR. After over-expression or silencing of LINC00261 and inhibition of miR-620 expression, the cells were irradiated with 4 Gy 60Coγ-ray. Clone formation assay was performed to detect the radiosensitivity of nasopharyngeal carcinoma cells. Flow cytometry was used to detect cell apoptosis. Western blot was utilized to detect the expression levels of Cleaved caspase-3 and Cleaved caspase-9 proteins. Luciferase reporter assay was adopted to analyze the targeting relationship between LINC00261 and miR-620. The changes in tumor formation were observed in tumor-bearing nude mice. Results:Compared with the radiosensitive tissues, the expression of LINC00261 was significantly down-regulated, whereas that of miR-620 was significantly up-regulated in radioresistant tissues (both P<0.05). After different doses of irradiation, the expression of LINC00261 was significantly down-regulated, whereas that of miR-620 was significantly up-regulated in 6-10B and HNE-3 cells (both P<0.05). After overexpression of LINC00261 and interference with miR-620 expression, the expression levels of Cleaved caspase-3 and Cleaved caspase-9 were significantly up-regulated (both P<0.05), the cell apoptosis rate was remarkably increased ( P<0.05) and the cell survival fraction was significantly enhanced in 6-10B and HNE-3 cells ( P<0.05). LINC00261 targetedly regulated the expression of miR-620. Overexpression of miR-620 could attenuate the radiosensitization and pro-apoptotic effects of LINC00261 overexpression on nasopharyngeal carcinoma cells. LINC00261 overexpression could significantly reduce the tumor formation weight of nasopharyngeal carcinoma in nude mice ( P<0.05). Conclusion:Overexpression of LINC00261 can increase the radiosensitivity of nasopharyngeal carcinoma cells probably by targeted regulation of miR-620 expression.
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<p><b>OBJECTIVE</b>To investigate the prognostic factors relevant to sudden sensorineural hearing loss.</p><p><b>METHODS</b>The internationally accepted standardized clinical research methods, unified design, and unified program were adopted to conduct the prospective clinical multi-center study. The sudden deafness patients between 18 to 65 years old, with the course of this disorder less than two weeks, and without any medical treatments were collected, and then, divided into four types according to the hearing curve: type A, acute sensorineural hearing loss in low tone frequencies; type B, acute sensorineural hearing loss in high tone frequencies; type C, acute sensorineural hearing loss in all frequencies; and type D, total deafness. The factors, in terms of age, gender, type of initial audiogram, time delay before the first visit, and severity of hearing loss, were included in the analyses.</p><p><b>RESULTS</b>A total of 1 024 cases with single side sudden deafness were collected in the study from 33 hospitals in China from August 2007 to October 2011, inclusive of for 492 males (48.05%) and 532 females (51.95%). The average age was (41.2 ± 12.8) years old. There were 553 cases (54.00%) in left ear, and 471 cases (46.00%) in right ear. The curative effects of different types were shown as follows: the type in low tone frequencies had the highest rate of 90.73%, the type in all frequencies was 82.59%; the type of total deafness was 70.29%; and the type in high tone frequencies had the lowest rate of 65.96%. It had significant difference of the effective rate between different types (χ(2) = 231.58, P = 0.000). Age, time delay before first visit, and severity of initial hearing loss were significantly correlated with hearing improvement.</p><p><b>CONCLUSIONS</b>Initial audiogram of SSNHL might predict hearing recovery. The young in age and a short time delay before starting treatment are positive prognostic factors for hearing recovery in SSNHL. The initial severity of hearing loss is negative prognostic factor of hearing recovery.</p>