[Construction of Vectors Expressing Inhibiting Peptides for Nuclear Import and Its Effect on Growth and Migration of HeLa Cell].

OBJECTIVE: To construct the expression vectors for red fluorescent protein fused with inhibiting peptides for nuclear import (Bimax),and explore the location of Bimax and its potential effects on cell proliferation and migration in HeLa cells. METHODS: Two kinds of polynucleotide encoding inhibiting peptides for nuclear import were synthesis respectively and subsequently annealed for inserting into vector pDs-Red-C1. The recombinant plasmids were transfected into competent bacterial DH-5α. After transfection,the positive bacteria were picked up for DNA sequencing. The recombinant plasmids pDs-Red-Bimax2,pDs-Red-Bimax1 and negative plasmid pDs-Red-C1 were transfected into HeLa cells respectively according to Lipofectamine2000 protocol. After transfection,the expression and location of red fluorescent protein were observed with fluorescence microscope. Furthermore,MTT assay and cell-migration assay were used to detect the proliferation and migration of Bimax transducted cells. RESULTS: DNA sequencing showed that the polynucleotides encoding Bimax1 or Bimax2 were inserted into pDs-Red-C1 vector successfully. After transfected into HeLa cells,the inhibiting peptide induced red fluorescent protein locating in nuclear. Furthermore,either the fusion protein RFP-Bimax1 or RFP-Bimax2 can suppress the proliferation and migration of HeLa cells. CONCLUSION: The expression vectors for red fluorescent protein fused with inhibiting peptides for nuclear import were successfully constructed. In addition,the fusion proteins were expressed and located in nuclear and suppressed the proliferation and migration of tumor cells.

[Expression of miR-140-5p and prediction of its target gene in human mesenchymal stem cells during adipogenic differentiation].

OBJECTIVE: To screen the differentially expressed miRNAs and their target genes in adipogenic differentiation of human bone marrow mesenchymal stem cells (hMSCs) to better understand the mechanism for regulating the balance between osteoblast and adipocyte differentiation. METHODS: Cultured hMSCs were induced for adipogenic differentiation, and at 0, 7, 14, and 21 days of induction, the cells were examined for miRNA and mRNA expression profiles using miRNA chip and transcriptome sequencing (RNA-seq) techniques. Correlation analysis was carried out for the miRNAs and mRNAs of potential interest. The databases including TargetScan, PicTar and miRanda were used to predict the target genes of the differentially expressed miRNA. RESULTS: The expression of miR-140-5p was down-regulated and leukemia inhibitory factor receptor (LIFR) expression increased progressively during adipogenic differentiation of hMSCs, showing a negative correlation between them. Target gene prediction using the 3 databases identified LIFR as the target gene of miR-140-5p. CONCLUSION: miRNA-140-5p may play an important role by regulating its target gene LIFR during adipogenic differentiation of hMSCs.