Background: This study investigated the mechanism of drug resistance in non-small cell lung cancer (NSCLC) patients. We specifically studied whether long noncoding RNAs influence drug resistance in NSCLC to discover new therapeutic targets to increase the survival rate of drug-resistant NSCLC patients. Methods: Tissue samples were collected from NSCLC patients, and total RNA was isolated for assessment of HOTAIR expression and drug resistance status. MTT assays, tumor sphere formation assays, and western blot were performed to cytologically determine the relationship between HOTAIR expression and cisplatin resistance, as well as to elucidate the potential molecular mechanism involved. Results: HOTAIR expression in tissues of drug-resistant NSCLC patients was higher than that of nondrug-resistant patients. HOTAIR expression was elevated in cisplatin-resistant cell strains (A549/CDDP), and reducing HOTAIR expression increased the sensitivity of A549/CDDP cells to cisplatin. In addition, overexpression of HOTAIR in A549 cells increased resistance to cisplatin. Tumor sphere formation assays showed that the volume of spheres formed by cell strains expressing elevated levels of HOTAIR was greater than that of cell strains with low expression. Western blot experiments showed that elevated expression of HOTAIR upregulated tumor stem cell-related biomarkers and HOTAIR expression was directly related to Klf4 expression.Conclusions: Elevated HOTAIR expression is associated with drug resistance in NSCLC patients and is related to Klf4 upregulation, providing a new therapeutic target for drug-resistant NSCLC patients.

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Background/Aims: Ketamine has been reported to exert anti-inflammatory effects on astrocytes stimulated by lipopolysaccharide (LPS) in vitro and in vivo. However, the mechanism has not been elicited clearly. The aim of this study was to investigate the effects of ketamine on TLR4 expression and NF-ĸB-p65 phosphorylation, as well as the production of proinflammatory cytokines in LPS challenged astrocytes. Methods: Astrocytes were stimulated with LPS (1µg/ ml) in the absence and presence of various concentrations of ketamine (10, 100, 1000µM). The concentrations of IL-1β, IL-6 and TNF-α were measured by ELISA, the expression of glial fibrillary acidic protein (GFAP) in astrocytes was detected by immunofluorescence staining, the level of phosphorylated NF-ĸB p65 and the expression of TLR4 were detected by western blotting. Results: LPS increased TLR4 expression and the phosphorylation of NF-ĸB p65 subunit as well as GFAP expression and the production of IL-1β, IL-6 and TNF-α in cultured astrocytes. Ketamine (100 and 1000 µM) reduced the expression of GFAP and the production of these proinflammatory cytokines, inhibited the expression of TLR4 and attenuated the phosphorylation of NF-ĸB p65 in astrocytes challenged by LPS. Conclusion: The inhibitory effects of ketamine on LPS-induced astrocytes activation and inflammation response may be mediated by suppressing NF-ĸB activation through reducing the expression of TLR4.

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Background Neuroblastoma (NB) displays the most heterogeneity in clinical manifestation. The insulin-like growth factor 1 receptor (IGF1R) has long been recognized for its role in tumourigenesis and growth. The IGF/IGF1R pathway is important in maintaining cell survival. It is reported that IGF1R participates in the occurrence of NB, but the mechanism is still unclear. Methods Human NB cell lines IMR-32 and SH-SY5Y were recruited in this study. IGF1R was knocked down by transfection with short hairpin RNA. Signal transducer and activator of transcription 3 (STAT3) expression was inhibited by Cryptotanshinone treatment. Cell proliferation, migration, and invasion were determined by MTT assay, wound healing assay, and cell invasion assay, respectively. The cancer stem cell properties were characterized by tumour sphere formation assay and colony formation assay. The mRNA and protein expression levels of related proteins were detected by RT-PCR and Western blot, respectively. Results The knockdown of IGF1R inhibits NB cell tumourigenesis and the epithelial-mesenchymal transition (EMT) of NB cells. Additionally, IGF1R was found to stimulate cancer stem cell-like properties in NPC cells. The knockdown of IGF1R significantly reduced the phosphorylation of AKT, and STAT3, indicating that the activation of the AKT and STAT3 pathways was inhibited by IGF1R knockdown. Furthermore, IGF1R was demonstrated to stimulate cancer stem cell-like properties in NB cells via the regulation of the STAT3/AKT axis. Conclusion IGF1R promotes cancer stem cell properties to facilitate EMT in neuroblastoma via the STAT3/AKT axis.