miR-140-Modified Bone Marrow Mesenchymal Stem Cells Enhance Chemotherapy Sensitization in Cervical Squamous Cell Carcinoma Cells via Targeting Microtubule Depolymerization Protein 1 (STMN1)

Effect of bone marrow mesenchymal stem cells (BMSCs) on the sensitivity of chemotherapy drugs and microRNAs (miRNAs) is still unclear. This study explored the role of miR-140 modified BMSCs in enhancing paclitaxel sensitivity of cervical squamous cell carcinoma (CSCC). Hela cells, BMSCs cells, and miR-140 modified BMSCs were transfected with miR-140 mimic, miR-140 inhibitor, and miR-140 NC, respectively. After transfection, they were co-cultured with Hela cells and paclitaxel to set up miR-140 mimic group, miR-140 inhibitor group, and miR-140 NC group (without paclitaxel treatment) followed by analysis of cell proliferation, apoptosis, ROS generation, expression of miR-140, STMN1, STAT3, p-STAT3, and survivin mRNA and protein. miR-140 inhibitor group showed lowest cell proliferation number and expressions of miR-140, STMN1, STAT3, p-STAT3, and survivin mRNA and protein with highest number of apoptotic cells, which were all reversed in miR-140 mimic group. There was a positive correlation between STMN1 level and miR-140 expression (r = 0.449, P = 0.108). BMSCs modified with miR-140 inhibitor can target STMN1, enhance the sensitivity of chemotherapy drugs, and exert an inhibitory effect on CSCC cell proliferation, suggesting that STMN1 might be a therapy target for treating CSCC.

PolyPurine Reverse Hoogsteen Hairpins Work as RNA Species for Gene Silencing

PolyPurine Reverse Hoogsteen Hairpins (PPRHs) are gene-silencing DNA-oligonucleotides developed in our laboratory that are formed by two antiparallel polypurine mirror repeat domains bound intramolecularly by Hoogsteen bonds. The aim of this work was to explore the feasibility of using viral vectors to deliver PPRHs as a gene therapy tool. After treatment with synthetic RNA, plasmid transfection, or viral infection targeting the survivin gene, viability was determined by the MTT assay, mRNA was determined by RT-qPCR, and protein levels were determined by Western blot. We showed that the RNA-PPRH induced a decrease in cell viability in a dose-dependent manner and an increase in apoptosis in PC-3 and HeLa cells. Both synthetic RNA-PPRH and RNA-PPRH intracellularly generated upon the transfection of a plasmid vector were able to reduce survivin mRNA and protein levels in PC-3 cells. An adenovirus type-5 vector encoding the PPRH against survivin was also able to decrease survivin mRNA and protein levels, leading to a reduction in HeLa cell viability. In this work, we demonstrated that PPRHs can also work as RNA species, either chemically synthesized, transcribed from a plasmid construct, or transcribed from viral vectors. Therefore, all these results are the proof of principle that viral vectors could be considered as a delivery system for PPRHs.

MicroRNA-140-5p inhibits salivary adenoid cystic carcinoma progression and metastasis via targeting survivin

Background Salivary adenoid cystic carcinoma (SACC) is one of the most frequent carcinomas derived from the salivary gland. Growing evidence implied the involvement of microRNAs (miRNAs) in SACC progression and metastasis. This study aimed to determine the regulatory role of miR-140-5p in SACC progression and metastasis and to explore the underlying mechanisms. Materials and methods MiR-140-5p and survivin mRNA expression levels were determined by quantitative real-time PCR; protein levels were evaluated by western blot assay; cell proliferation, growth, invasion, apoptosis and caspase-3 activity were evaluated by respective in vitro functional assays; xenograft nude mice model was used to assess the in vivo tumor growth; a luciferase reporter assay determined the interaction between miR-140-5p and survivin. Results MiR-140-5p overexpression suppressed SACC cell proliferation and invasion, induced cell apoptosis and inhibited in vivo tumor growth of SACC cells. The loss-of-function studies showed that miR-140-5p knockdown enhanced SACC cell proliferation and invasion, inhibited cell apoptosis and led to an accelerated in vivo tumor growth. The bioinformatics prediction and luciferase reporter assay revealed that miR-140-5p directly targeted survivin 3′ untranslated region, and survivin was inversely regulated by miR-140-5p. Knockdown of survivin exerted tumor-suppressive effects on SACC cells, while enforced expression of survivin counteracted the tumor-suppressive actions of miR-140-5p overexpression in SACC cells. Mechanistically, miR-140-5p modulated the protein expression levels of apoptosis- and epithelial-mesenchymal transition-related mediators as well as matrix metallopeptidase-2/-9 via targeting survivin. More importantly, the down-regulation of miR-140-5p and the up-regulation of survivin were detected in the SACC clinical tissues, and miR-140-5 expression was inversely correlated with survivin mRNA expression level in SACC tissues. Conclusion Our data indicated that miR-140-5p suppressed SACC cell proliferation and invasion, induced cell apoptosis via regulating survivin expression. The present study provide evidence that that miR-140-5p could be a promising target for treating SACC, which requires further investigations.