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Transforming growth factor beta (TGF-?), a pleiotropic cytokine, promotes cell proliferation and migration in multiple cancers, including nasopharyngeal carcinoma (NPC). microRNA-124 (miR-124) becomes downregulated in NPC and inhibits the tumorigenesis of this disease. However, the role of miR-124 in TGF-?-induced NPC development remains unknown. In this study, constant TGF-? stimulation repressed miR-124 expression, whereas miR-124 overexpression antagonized TGF-?-promoted NPC cell growth and migration. miR-124 overexpression decreased p-SMAD2/3, SMAD4, and p-ERK levels, indicating that ectopic miR-124 overexpression inhibited SMAD and non-SMAD pathways. Pro-oncogenic lncRNA MALAT1 was targeted by miR-124 that regulated ERK/MAPK by targeting MALAT1 independent of the SMAD signaling pathway. In conclusion, our work clarified the significant role of miR-124 in TGF-? signaling pathways independent of the SMAD signaling pathway and showed the potential of miR-124 as a new therapeutic target against NPC., (Copyright © 2018. Published by Elsevier Masson SAS.)

Background: Long noncoding RNAs (lncRNAs) are known as key regulators in many cancer types, but their biological functions in nasopharyngeal carcinoma (NPC) remain largely unknown. In the present study, we aim to explore the role of the lncRNA ZNRD1-AS1 in NPC tumor development. Methods: The role of ZNRD1-AS1 in NPC tissues and cells was explored by using quantitative real-time PCR assay. Cellular behavioral experiments were used in testing NPC cell proliferation, invasion, and migration. Luciferase reporter assay, RNA-binding protein immunoprecipitation, and Western blot analysis were used in estimating the associations among ZNRD1-AS1, miR-335, and ROCK1. Results: ZNRD1-AS1 expression was elevated in the NPC tissues and cells, and ZNRD1-AS1 overexpression was positively correlated with advanced TNM stage and the presence of lymph node metastasis. Our biological experiments indicated that ZNRD1-AS1 knockdown reduces NPC cell invasion and metastasis. Further analyses revealed that ZNRD1-AS1 as a ceRNA promotes the migration and invasion of NPC cells by sponging miR-335. We provided evidence that ZNRD1-AS1 facilitates the invasion and metastasis of NPC cells via the miR-335–ROCK1 axis. Conclusion: Our data shed light on the oncogenic role of ZNRD1-AS1 in NPC tumor development, and a promising therapeutic target for NPC was identified. [ABSTRACT FROM AUTHOR]

Background: Mounting evidence has reported that microRNA-154-5p (miR-154-5p) is involved in the development of multiple cancers, but its function in nasopharyngeal carcinoma (NPC) remains not well investigated. Methods: Real-time quantitative PCR (qRT-PCR) was used to detect miR-154-5p expression in NPC tissues and cells. CCK8, colony formation, wound healing and transwell assays were performed to assess cell proliferation, migration and invasion. Dual-luciferase reporter assays and Western blots were performed to confirm the target gene of miR-154-5p. Rescue experiments were conducted to explore the influence of target gene KIF14 on the functions of miR-154-5p. Xenograft tumor model was conducted to detect the effect of miR-154-5p in vivo. Results: qRT-PCR results revealed that the expression of miR-154-5p was down-regulated in NPC tissues and cell lines compared to normal nasopharyngeal tissues and cell line. Overexpression of miR-154-5p inhibited cell migration and invasion. However, miR-154-5p had no influence on the proliferation of NPC cells. MiR-154-5p overexpression suppressed xenograft tumor metastasis in vivo. Dual-luciferase reporter analysis identified KIF14 as a target gene of miR-154-5p. Rescue experiments showed that knockdown of KIF14 reversed the effect of inhibiting miR-154-5p expression on NPC cell migration and invasion. Conclusion: Taken together, miR-154-5p suppresses tumor migration and invasion by targeting KIF14 in NPC. The newly identified miR-154-5p/KIF14 interaction offers further insights into the progression of NPC, which may represent a novel target for NPC diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Background: E2F transcription factor 3 (E2F3) is oncogenic and dysregulated in various malignancies. Complex networks involving microRNAs (miRNAs) and E2F3 regulate tumorigenesis and progression. However, the potential roles of E2F3 and its target miRNAs in nasopharyngeal carcinoma (NPC) are rarely reported. Methods: E2F3 expression was detected in human NPC tissues and cell lines through quantitative real-time PCR. NPC cell proliferation, migration, and invasion were evaluated in vitro by colony forming, cell counting kit-8, wound healing, and Transwell invasion assays. Publicly available database software was used to explore the target miRNAs of E2F3. Dual-luciferase reporter assay was performed to identify the direct relationship. The function of miRNAs in vivo was investigated by using a tumor xenograft model. Results: E2F3 was upregulated in NPC cell lines and tissues, and its exotic expression promoted NPC cell invasion and migration. E2F3 was identified as a target of miR-432, which restrained NPC cell invasion and migration in vitro and in vivo. Further experiments revealed that miR-432 repressed the invasion and migration potential of NPC cells by modulating E2F3 expression. Conclusion: miRNA-432 suppressed the malignant biological behavior of NPC cells by targeting E2F3. This study provided further insights into NPC prognosis and treatment. [ABSTRACT FROM AUTHOR]