ABSTRACT
【Objective】 To investigate the effects of miR-126-3p targeting chemokine receptor 1 (CCR1) in exosomes derived from bone marrow mesenchymal stem cells (BMSC) on the proliferation, migration, and invasion of lung cancer cells. 【Methods】 BMSC cells were cultured; exosomes were extracted and identified by the exosomal marker proteins CD63 and TSG101. After exosome culture of A549 cells for different durations (0, 24, 48, and 72 h), cell survival rate was detected by CCK-8, mRNA levels of miR-126-3p and CCR1 were detected by qRT-PCR, and cell migration and invasion abilities were detected by Transwell assay. The relative expressions of CCR1, epithelial cadherin (E-cad), neural cadherin (N-cadherin), and Vimentin were detected by Western blotting. 【Results】 Exosomes had round or oval cup-shaped structures with bright edges and dark middle, with a particle size distribution of about 152 nm, expressing CD63 and TSG101 proteins. The expression of miR-126-3p in exosomes was higher than that in A549 cells. The expression of miR-126-3p was low in A549 cells and that of CCR1 mRNA was high. However, after co-culture with exosomes, the expression of miR-126-3p in A549 cells was increased, while the expression of CCR1 was decreased. A549 cells were cocultured with exosomes for 0, 24, 48, and 72 h. The survival rate, migration and invasion abilities, CCR1 gene and protein expression levels, and N-cad and Vimentin protein expression levels of A549 cells decreased gradually with the extension of culture time. The level of miR-126-3p and the expression of E-cad protein increased gradually with the extension of culture time. 【Conclusion】 The co-culture of exosomes derived from bone marrow mesenchymal stem cells with A549 cells can increase the expression level of miR-126-3p, and miR-126-3p can reduce the proliferation, migration, and invasion of A549 cells by targeting the inhibition of CCR1 expression.
ABSTRACT
Objective@#To evaluate the effect of human CCR1 (hCCR1) gene overexpression on the migration of human bone marrow-derived mesenchymal stem cells (hMSCs) towards hepatocellular carcinoma (HCC), and to examine the application prospects of MSCs as gene delivery vectors in the treatment of HCC.@*Methods@#The hCCR1 gene was subcloned into a lentiviral vector to generate the recombinant plasmid pLV-hCCR1. The pLV-hCCR1 plasmid and two other packaging plasmids were co-transfected into 293T cells using calcium phosphate, and the virus-containing supernatant was collected. hMSCs were then infected with the recombinant lentivirus, and the expression of hCCR1 mRNA and protein was analyzed by RT-PCR and Western blot, respectively. The effect of CCR1 gene overexpression on the in vitro migration of hMSCs was examined using the Transwell migration assay. Orthotopic nude mice models of HCC were established using the MHCC-97H-GFP cell line, and the mice were divided into two groups (n = 8 per group). hMSCs were then intravenously injected via the tail vein into the tumor-bearing nude mice to examine the effect of hCCR1 overexpression on the in vivo migration of hMSCs towards HCC. Unpaired Student’s t-test was used for two-group comparisons, and one-way ANOVA was used for multi-group comparisons.@*Results@#Restriction enzyme digestion and DNA sequencing demonstrated that the recombinant plasmid pLV-hCCR1 was constructed successfully. The LV-hCCR1 lentivirus packaged by 293T cells has high infection efficiency in hMSCs, and hCCR1 was overexpressed in hMSCs after LV-hCCR1 infection. Transwell migration assay showed that hCCR1-transfected hMSCs had significantly enhanced migration towards HCC cell line-derived condition medium (CM) compared with the control RFP-hMSCs [(134.8±15.7)/LPF vs (83.5±10.9)/LPF, t = 10.40, P < 0.01]. In vivo migration experiment also demonstrated that there was significantly higher number of hCCR1-hMSCs localized within the MHCC-97H-GFP xenografts than hMSCs-RFP on day 14 following intravenous injection of hMSCs in mice [(86.7±14.1)/HPF vs (54.5±9.6)/HPF, t = -7.32, P < 0.01].@*Conclusion@#Overexpression of CCR1 gene can significantly enhance the migration capacity of hMSCs towards HCC cells in vitro and in vivo. This study provides evidence for potential clinical application of MSCs as more effective delivery vehicles in cancer gene therapy.