RESUMO
PURPOSE: Mounting evidence highlights the essential role of TRIM44 in tumor initiation and malignant progression in several cancers; however, the function of TRIM44 in osteosarcoma (OS) remains unknown. In this study, we aim to investigate the role of TRIM44 and reveal its regulation by deregulated miRNAs in OS. MATERIALS AND METHODS: The expression profiles of TRIM44 were examined by immunohistochemistry, Western blotting, and qRT-PCR. The biological functions of TRIM44 were investigated through siRNA-mediated knockdown experiments. The regulation of TRIM44 by miR-410 was confirmed by Western blotting, dual luciferase reporter assays, and rescue experiments. RESULTS: TRIM44 was upregulated in OS tissues and cell lines, and its overexpression was positively correlated with TNM stage, metastasis, and recurrence. Knockdown of TRIM44 in OS cells suppressed cell proliferation, migration, invasion, and epithelial-mesenchymal transition. In addition, we identified TRIM44 as a novel target gene of miR-410 and miR-410 was remarkably downregulated in OS. Moreover, overexpression of miR-410 suppressed proliferation, migration, invasion, and epithelial-mesenchymal transition of OS cells by directly targeting TRIM44 expression. Furthermore, reintroduction of TRIM44 partially reversed miR-410-induced inhibitory effects on OS cells. CONCLUSION: Collectively, our findings indicate that the miR-410/TRIM44 link is critical in the control of OS progression.
RESUMO
Cullin 4A (CUL4A) overexpression has been reported to be involved in the carcinogenesis and progression of many malignant tumors. However, the role of CUL4A in the progression of gastric cancer (GC) remains unclear. In this study, we explored whether and how CUL4A regulates proinflammatory signaling to promote GC cell invasion. Our results showed that knockdown of CUL4A inhibited GC cell migration and invasion induced by lipopolysaccharide (LPS) stimulation. We also found that both CUL4A and nuclear factor-kappa B (NF-κB) protein expressions were enhanced by LPS stimulation in HGC27 GC cell lines. Furthermore, knockdown of CUL4A decreased the protein expression of NF-κB and mRNA expression of the downstream genes of the NF-κB pathway, such as matrix metalloproteinase (MMP) 2, MMP9, and interleukin-8. Our immunohistochemistry analysis on 50 GC tissue samples also revealed that CUL4A positively correlated with NF-κB expression. Taken together, our findings suggest that CUL4A may promote GC cell invasion by regulating the NF-κB signaling pathway and could be considered as a potential therapeutic target in patients with GC.
RESUMO
Gastric cancer (GC) is the fourth most prevalent type of cancer worldwide, which is usually caused by the interaction between environmental and genetic factors, or epigenetic aspects. Referring to the non-coding RNAs, miR-128b has been reported to be associated with many tumour cases, and exerts distinct functions in different types of cancers. However, the function of miR-128b in GC onset and progression largely remains unknown. In the present study, we found that miR-128b expression was down-regulated in tissues from 18 GC patients and 3 carcinoma cell lines. In turn, over-expression of miR-128b suppressed GC cell proliferation, invasion and promoted apoptosis. Moreover, miR-128b was predicted to bind the 3'UTR of PDK1 gene using bioinformatic target-screening tools. Accordingly, ectopic expression of miR-128b inhibited the PDK1 expression at both transcriptional and post-transcriptional levels, and furthermore, the expression of gene tailed by the 3'UTR of PDK1 gene was significantly decreased in a dualluciferase reporter assay, suggesting that PDK1 was a direct target of miR-128b in GC cells. In the conditon of miR- 128b over-expression, we also observed spontaneous inactivation of the Akt/NF-κB signalling, implying PDK1 was a potential regulator of this pathway. In conclusion, our study shed some novel light on miR-128b-PDK1/Akt/NF-κB axis on GC progression.
