ABSTRACT
MicroRNA-20a-5p (miR-20a-5p) has been shown to function as a tumor promoter factor in several cancers. However, its role in small cell lung cancer (SCLC) remains unclear. In this study, we have made an attempt to measure the tumor tissue levels of miR-20a-5p in patients with SCLC using quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). The biological function of miR-20a-5p in SCLC cells was investigated in vitro and in vivo studies, including cell proliferation, migration assays and tumorigenicity in nude mice. Meanwhile?we conducted the luciferase reporter assay to verify the biological relationship between miR-20a-5p and CCNG2. The expression of miR-20a-5p was significantly upregulated in human SCLC compared to that in normal tissues. Kaplan-Meier analysis indicated that patients with high expression of miR-20a-5p are closely related with the shorter survival of SCLC. Further, multivariate analysis showed that miR-20a-5p was an independent prognostic factor. Increasing miR-20a-5p expression promotes the proliferation, migration and invasion of the NCI-H446 cells in vitro and in vivo. Dual-luciferase reporter gene assay demonstrated that miR-20a-5p directly targets CCNG2. These findings suggest that miR-20a-5p levels might be a novel diagnostic and prognostic marker of SCLC. Inhibiting miR-20a-5p could be a promising therapeutic strategy for SCLC.
ABSTRACT
Objective: To study the effect of nuclear factor erythroid-2-related factor 2(Nrf2) and the downstream gene grainyhead-like 2(GRHL2) on epithelial ovarian cancer cell lines and the interaction of Nrf2 and GRHL2. Methods: We conducted ChlP-PCR assay to test the binding of Nrf2 with six candidate genes including GRHL2. Furthermore, we proved whether Nrf2 could bind with the GRHL2 promoter and transcriptionally activate the GRHL2 gene or not. Moreover, if the overexpression and knockdown of Nrf2 could increase and decrease the GRHL2 protein respectively. Results: We discovered that fallopian tube epithelial cells taken from epithelial ovarian cancer patients and ovarian cancer cell lines highly expressed the Nrf2 and GRHL2 at mRNA level. The overexpression and knockdown of Nrf2 could increase and decrease the cells activity, respectively. However, the knockdown of GRHL2 could inhibit the influence of Nrf2 overexpression. Conclusion: Nrf2 promotes the activity of epithelial ovarian cancer cells via modulating the GRHL2 gene transcriptionally.
ABSTRACT
PURPOSE: To identify the polymorphism in the regulatory region of trabecular meshwork inducible glucocorticoid response(TIGR) gene and evaluate the association of it with glaucoma. METHODS: 5'regulatory region of TIGR gene of 101 normal persons and 91 unrelated glaucoma patients were analyzed by DNA sequencing and restriction enzyme digestion. To know the possible effects of the polymorphism on the transcription rate of TIGR gene, electrophoretic mobility shift assay and luciferase reporter gene assay were performed with cultured cells, and their extracts of trabecular meshwork and ciliary body in which the gene was expressed. RESULTS: Of the 480 bp examined, G to A transition(G-241A) located at 241 bp upstream from transcription start site was identified and its frequency of occurrence was proved to be higher in steroid induced glaucoma patients(18.9%) compared with that in normal population(8.9%), POAG(8.3%) and normal tension glaucoma patients(6.7%, P<0.05). In mobility shift assay, the G-241A probe was proved to have affinity to some DNA-binding proteins and its affinity was revealed to be two times stronger than that of normal sequence. The luciferase activities, however, were observed to be similar in cells transfected with vectors having normal promoter sequence or G-241A containing one. CONCLUSION: The result suggest that G-241A itself is not a cause of steroid-induced glaucoma but is in linkage disequilibrium with the actual causes of the disease.