BackgroundHigh levels of SOX2 protein are correlated with increased dissemination of breast cancer. However, the underlying molecular mechanisms are not fully understood.MethodsIn this study we investigate the role of SOX2 in breast cancer metastasis using multiple in vitro and in vivo assays including cell culture, shRNA-mediated knockdown, wound healing, colony formation, transwell chamber, xenograft and tail vein injection. Moreover, western blot, immunostaining, microarray and real-time PCR were used to determine the change of protein and miRNA levels. Luciferase assays were also used to evaluate activity which TUSC3 is a target of miR-181a-5p and miR-30e-5p, and the clinical survival relevance was analyzed by Kaplan-Meier analysis.ResultsWe identified a novel pathway involving SOX2 regulation of microRNAs to control the proliferation and migration of breast cancer cells. shRNA-mediated knockdown of SOX2 inhibits breast cancer cell expansion and migration. More importantly, we found that these changes are accompanied by significant reduction in the levels of two microRNAs, miR-181a-5p and miR-30e-5p. Overexpression of these two microRNAs leads to reduced protein levels of Tumor Suppressor Candidate 3 (TUSC3) in breast cancer cells; mutations of the potential binding sites in the 3’-UTR of TUSC3 abrogate the inhibitory effects of the microRNAs. We further found that upregulation of TUSC3 expression leads to reduced proliferation and migration of breast cancer cells. In human breast cancer samples the levels of TUSC3 protein are inversely correlated with those of SOX2 protein.ConclusionsTaken together, our work reveals a novel SOX2-mediated regulatory axis that plays critical roles in the proliferation, migration and invasiveness of breast cancer cells. Targeting this axis may provide beneficial effect in the treatment of breast cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-017-0632-9) contains supplementary material, which is available to authorized users.

BackgroundAn effective method for obtaining resistant transgenic plants is to induce RNA silencing by expressing virus-derived dsRNA in plants and this method has been successfully implemented for the generation of different plant lines resistant to many plant viruses.ResultsInverted repeats of the partial Tobacco mosaic virus (TMV) movement protein (MP) gene and the partial Cucumber mosaic virus (CMV) replication protein (Rep) gene were introduced into the plant expression vector and the recombinant plasmids were transformed into Agrobacterium tumefaciens. Agrobacterium-mediated transformation was carried out and three transgenic tobacco lines (MP16-17-3, MP16-17-29 and MP16-17-58) immune to TMV infection and three transgenic tobacco lines (Rep15-1-1, Rep15-1-7 and Rep15-1-32) immune to CMV infection were obtained. Virus inoculation assays showed that the resistance of these transgenic plants could inherit and keep stable in T4 progeny. The low temperature (15℃) did not influence the resistance of transgenic plants. There was no significant correlation between the resistance and the copy number of the transgene. CMV infection could not break the resistance to TMV in the transgenic tobacco plants expressing TMV hairpin MP RNA.ConclusionsWe have demonstrated that transgenic tobacco plants expressed partial TMV movement gene and partial CMV replicase gene in the form of an intermolecular intron-hairpin RNA exhibited complete resistance to TMV or CMV infection.

In the context of the Covid-19, the present study designed a longitudinal study to examine the relationship among interpersonal alienation, meaning in life and smartphone addiction. Meanwhile, with the development of the epidemic whether there would be changes in the three variables also was examined. A sample of 579 university students (baseline mean age = 20.59, SD = 2.20) finished the anonymous questionnaires about interpersonal alienation, meaning in life and smartphone addiction. Three repeated measurements were obtained in June, September and December 2020. The finding indicated that university students' interpersonal alienation and meaning in life significantly increased, and the risk of smartphone addiction significantly decreased with the epidemic under control. Besides, meaning in life in the middle mitigating period of the epidemic mediated the relationship between interpersonal alienation in the early severe period of the epidemic and smartphone addiction in the basic end period of the epidemic. The study contributes to our understanding of how low levels of interpersonal alienation may improve meaning in life and reduce the risk of smartphone addiction. What's more, it provides scientific suggestions for the prevention and intervention of the adverse effects during public health emergencies.