Extensive profiling of circular RNAs and the potential regulatory role of circRNA-000284 in cell proliferation and invasion of cervical cancer via sponging miR-506.

Circular RNAs (circRNAs) are key regulators in the development and progression of human cancers, however its role in cervical cancer tumorigenesis is not well understood. The present study aims to investigate the expression profiles and potential modulation of circRNA on cervical cancer carcinogenesis. Human circRNA microarray was performed to screen for abnormally expressed circRNA in cervical cancer cells and circRNA-000284 was identified as one circRNA significantly upregulated in cervical cancer cells. Subsequent mechanistic investigations suggested that knockdown of circRNA-000284 suppressed cell proliferation and invasion, and caused G0/G1 phase cell cycle arrest. By performing anti-AGO2 RNA precipitation and luciferase reporter assay, we identified miR-506 as the circRNA-000284-associated miRNA. Furthermore, Snail-2 was identified as a direct target of miR-506, and circRNA-000284 could positively regulate the expression of Snail-2. Finally, the tumor promoting effect of circRNA-000284 was abolished by co-expression of miR-506 mimics or Snail-2 silencing vector. In conclusion, circRNA-000284 promotes cell proliferation and invasion in cervical cancer, and may serve as a promising therapeutic target for cervical cancer patients. Therefore, silence of circRNA-000284 could be a future direction to develop a novel treatment strategy.

Autonomic nervous infiltration positively correlates with pathological risk grading and poor prognosis in patients with lung adenocarcinoma.

BACKGROUND: Perineural invasion has been found in several types of human tumors, and is associated with poor prognosis; however, few studies have examined perineural invasion in lung cancer. We evaluated the relationship between autonomic nervous densities, pathological risk grading, and prognosis in patients with lung adenocarcinoma (LADC). METHODS: Neural fiber expression was examined by immunofluorescence in resected lung specimens in control patients (n = 30), and low-risk (n = 22), and high-risk LADC patients (n = 43). The nerve densities of normal lung tissue and abnormal lung tissues in the tumor and surrounding tissues were evaluated by a semi-quantitative score method. RESULTS: Increased sympathetic fibers mainly infiltrated the paratumoral area, while increased parasympathetic fibers were largely restricted to the tumor (paratumor vs. tumor, P = 0.000 in high, P = 0.034 in low; each). In addition, high-risk patients presented the highest density of neural fibers, followed by low-risk and control patients ( P = 0.000; each). In Kaplan-Meier survival analysis, the densities of sympathetic fibers in paratumoral tissue and parasympathetic fibers in the tumor, respectively, correlated with poor recurrence-free survival in patients who were not treated with adjuvant therapy ( P < 0.001; each). Further multivariate analysis showed that these two factors were associated with poor prognosis in all LADC patients ( P = 0.024 sympathetic fibers; P = 0.037 parasympathetic fibers). CONCLUSION: These findings reveal a positive correlation between nervous infiltration and risk of poor prognosis in patients with LADC.