ABSTRACT
BACKGROUND@#MicroRNAs (miRNAs) are non-coding small molecule RNAs that are widely found in eukaryotic organisms, although some miRNAs have been found in tumors, the expression and effects of miR-665 on small cell lung cancer (SCLC) are unclear. The aim of this study was to analyze the effects of miR-665 on proliferation, cycle, invasion and migration of SCLC cells, and to explore the role of miR-665 in SCLC and its working mechanism.@*METHODS@#The expression of miR-665 in SCLC tissues and adjacent normal tissues was detected by qRT-PCR. TargetScan predicted potential target genes for miR-665 and validated with dual luciferase reporter assays, qRT-PCR and Western blot. CCK8 assay, flow cytometry, Transwell and wound healing assay to detect the effects of miR-665 and LLGL1 on proliferation, invasion, migration and S-phase fraction of SCLC cell line NCI-H446, NCI-H1688. A nude mouse xenograft model of SCLC was constructed and the effect of miR-665 on tumor growth in mice was observed.@*RESULTS@#The expression of miR-665 in SCLC tissues was significantly higher than that in non-tumor normal tissues. MiR-665 could target 3'-UTR of LLGL1 and inhibit its expression. Compared with non-tumor normal tissues, the expression of LLGL1 was significantly lower in SCLC tissues. Inhibition of miR-665 expression could inhibit proliferation, S-phase fraction, invasion and migration ability of SCLC NCL-H446 cells, and interference LLGL1 expression could reverse this inhibition effect. Up-regulation of miR-665 expression could promoted proliferation, S-phase fraction, invasion and migration ability of SCLC NCI-H1688 cells, but this promotion effect was also reversed by overexpression of LLGL1. In a nude mouse xenograft model of SCLC, inhibition of miR-665 expression could up-regulate LLGL1 protein expression and inhibit tumor growth, while up-regulation of miR-665 expression could produce opposite results.@*CONCLUSIONS@#The expression of miR-665 is closely related to SCLC. miR-665 can promote the biological behavior of SCLC cells by inhibiting the expression of target gene LLGL1, and miR-665 play a role in tumor-promoting genes in SCLC.
ABSTRACT
Objective To explore the influences on biological function induced by hyperthermia in human lung cancer cell line H1299, and to investigate the possible molecular mechanism. Methods H1299 cells were cultured in vitro and divided into 2 groups. The cells in culture flasks of hyperthermia group were immersed into a water bath at 43 ℃for 1 h, and the cells of control group were cultured at 37 ℃. The cell growth was detected by CCK8 assay, and the cell cycle and apoptosis rates were detected by flow cytometry [propidium iodide (PI) staining and PI/Annexin V staining]. The effects of hyperthermia on migration and invasion abilities of H1299 cells were determined by Transwell migration and invasion assays, respectively. The expression of LLGL1 was measured by Western blot. Results The cell cycle had no significant difference between the two groups, but the apoptosis rate was significantly higher in hyperthermia group [(24.81 ±2.80) %] than that in control group [(11.73 ±1.55) %] (t= 7.709, P= 0.0021). The migrating cell number was decreased in hyperthermia group (25.67±4.81) than that in control group (85.00±10.31) (t=5.182, P=0.0066). The invasive cell number was also decreased in hyperthermia group (22.00±2.08) than that in control group (108.3.0±10.14) (t=8.342, P=0.0011). The expression level of LLGL1 protein in hyperthermia group was 4.2 times that in control group(t=3.028, P=0.0389). Conclusion Hyperthermia induces the cell apoptosis and inhibits migration and invasion abilities of H1299 cells, which maybe associate with increasing LLG1 expression.