MiRNA-regulated delivery of lincRNA-p21 suppresses β-catenin signaling and tumorigenicity of colorectal cancer stem cells

TNF-related apoptosis-inducing ligand (TRAIL) is a tumor-selective apoptosis inducer and has been shown to be promising for treating various types of cancers. However, the application of TRAIL is greatly impeded by the resistance of cancer cells to its action. Studies show that overexpression of some critical pro-survival proteins, such as survivin, is responsible for TRAIL resistance. In this study, we found that Aplysin, a brominated compound from marine organisms, was able to restore the sensitivity of cancer cells to TRAIL both in vitro and in vivo. Aplysin was found to enhance the tumor-suppressing capacity of TRAIL on several TRAIL-resistant cancer cell lines. TRAIL-induced apoptosis was also potentiated in A549 and MCF7 cells treated with Aplysin. Survivin downregulation was identified as a mechanism by which Aplysin-mediated TRAIL sensitization of cancer cells. Furthermore, the activation of p38 MAPK was revealed in Aplysin-treated cancer cells, and its inhibitor SB203580 was able to abrogate the promoting effect of Aplysin on the response of cancer cells to TRAIL action, as evidenced by restored survivin expression, elevated cell survival and reduced apoptotic rates. In conclusion, we provided evidence that Aplysin acts as a sensitizer for TRAIL and its effect on p38 MAPK/survivin pathway may partially account for this activity. Considering its low cytotoxicity to normal cells, Aplysin may be a promising agent for cancer treatment in combination with TRAIL.

Background: Drug resistance plays an important role in the failure of clinical therapy. This study aimed to identify the key genes related to cisplatin resistance in A549 human lung adenocarcinoma cells. Methods: The mRNA microarray dataset E-MEXP-3123 and miRNA dataset GSE43249 were downloaded from the Gene Expression Omnibus (GEO) database. The differentially expressed genes (DEGs) and miRNAs (DEMs) between parental and cisplatin-resistance A549 lung cancer cells were identified. Functional enrichment analysis and pathway analysis were performed by using the DAVID database. Protein-protein interactions of DEGs, microRNAs (miRNAs) network and their potential gene targets were formed by Cytoscape. Real-time quantitative polymerase chain reaction (qRT-PCR) was used to validate the identified candidate genes in cisplatin-resistant A549 cells. Results: Firstly, a total of 499 DEGs were identified from E-MEXP-3123. In gene ontology (GO) term analysis, DEGs were significantly involved in signal transduction, oxidation-reduction process, multicellular organism development, cell adhesion and inflammatory response. Pathway analysis showed that the most significant pathways were neuroactive ligand-receptor interaction, endocytosis and hippo signaling pathway. PPI network showed that the top five hub genes were CDH1 (cadherin 1), BDKRB2 (bradykinin receptor B2), FPR2 (formyl peptide receptor 2), CCR5 (C-C chemokine receptor type 5) and YWHAE (tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein epsilon). Secondly, 12 DEMs were identified from GSE43249, and the top six DEMs were miR-194, miR-192, miR-574-3p, miR-106b, miR-146a and miR-182. In subsequent qRT-PCR experiments, low expression levels of miR-192, miR-106b, miR-182 and high expression level of miR-574-3p were confirmed in cisplatin-resistant group compared with control group. Meanwhile as predicted, the overexpression of NCALD, SPIN1 that are miR-182 potential targets and the weak expression of PSMA4 that is miR-574-3p potential target were also experimentally validated in cisplatin-resistant lung cancer cells. Conclusions: These key genes identified in our study might provide new clues for developing effective strategies against cisplatin resistance during lung adenocarcinoma treatment.