Role of SNHG7-miR-653-5p-STAT2 feedback loop in regulating neuroblastoma progression.

Long noncoding RNAs (lncRNAs) are reported to be involved in the pathology of numerous cancers, including neuroblastoma (NB). lncRNA SNHG7 has been recognized as a carcinogen in several cancers, but its role in NB progression remains unknown. Our study revealed that SNHG7 expression was markedly higher in NB tissues than that in nontumor tissues. Besides, upregulated SNHG7 was greatly correlated with poor overall survival of NB patients. Functionally, the loss-of-function assays demonstrated that knockdown of SNHG7 inhibited cell proliferation, migration, invasion, and epithelial-mesenchymal transition in NB cells. Mechanically, the bioinformatics analysis predicted that miR-653-5p was the shared partner of SNHG7 and signal transducer and activator of transcription 2 (STAT2). Unsurprisingly, we further confirmed that SNHG7 could interact with miR-653-5p and therefore functioned as the ceRNA of STAT2 so as to regulate STAT2 expression in NB cells. Moreover, STAT2 expression was in inverse proportion to miR-653-5p level but in positive proportion to SNHG7 level in NB tissues. Importantly, the repressed NB progression induced by silenced SNHG7 was reversed by STAT2 overexpression or miR-653-5p inhibitors. Jointly, our findings elucidated SNHG7 facilitated NB progression through the miR-653-5p/STAT2 pathway, providing a novel therapeutic target and prognostic biomarker for this disease.

[Sequential expression of hypoxia-inducible factor 1alpha and its significance in secondary spinal cord injury].

OBJECTIVE: To investigate the expression pattern of hypoxia-inducible factor 1alpha (HIF-1alpha) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. METHODS: A total of 66 SD rats (female or male) with weight (250 +/- 20) g were randomly divided into 3 groups: normal control group (group A, n = 6), pseudo injury group (group B, n = 6), and spinal cord injury (SCI) group (group C, n = 54). In group A, no treatment was given as normal control. In group B, only laminectomy was applied. In group C, laminectomy was applied and static compression model of SCI was built at T10 level. The expression of HIF-1alpha was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with light staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of glial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-la was poorly expressed in group A and increased a little in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of ganglion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then declined. At 14 days, it appeared only in a small amount of ganglion cells of white matter. There was no significant difference in the number of HIF-1alpha positive cells between groups A and B (t = 1.325, P = 0.137). The number of HIF-1alpha positive cells at each time point in group C was more than those in groups A and B (P < 0.05), and there were significant differences between all time points in group C (P < 0.05). CONCLUSION: The expression of HIF-1alpha increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.