1-learn more IGFBP7 (J) (red arrow shows deep blue cells). As to show the exactitude of our experiment design, we used pcDNA3.1-IGFBP7 simultaneously expressed GFP and IGFBP7 rather than pcDNA3.1 plasmid containing only IGFBP7 gene. That was because, if we used pcDNA3.1 plasmid only containing IGFBP7 gene, we could not estimate the transfection efficiency

in-vivo experiments, and moreover, we could not discriminate whether high level of IGFBP7 expression in xenograft sections dued to plasmid transfection or physiological IGFBP7 synthesis of melanoma. Well, pcDNA3.1-IGFBP7 simultaneously expressed GFP and IGFBP7 could solve both of the problems, as shown in additional files 3, Figure S2. We evaluated apoptosis-induced effect in melanoma cells of pcDNA3.1 only containing IGFBP7 selleck screening library gene, and

in those of pcDNA3.1-IGFBP7 simultaneously expressed GFP and IGFBP7, finding out that insersion of GFP would not affect the expression of IGFBP7, as shown in additional files 3, Figure S1. Discussion It has been confirmed that transfection with anti-tumor plasmids is more specific, more efficient, and longer lasting for anti-tumor therapy than recombinant protein. Transfection of anti-tumor plasmids may have some advantages over the application of rIGFBP7, namely the less danger of immunological rejection and the low cost of synthesis and purification [3]. In addition, MM cells transfected with eukaryotic expression plasmids could have stable and effective expression of IGFBP7 gene. Our research demonstrated that pcDNA3.1-IGFBP7 click here vector promotes expression of IGFBP7 specifically and have a long-lasting effect. However, it is conflicting to our hypothesis that IGFBP7 expression should ascensus, but it was attenuate over time. not The possible explanation for this phenomenon

was attributed to the high performance of PCMV promoter contained in pcDNA3.1-IGFBP7, which would exhaust and be toxic to tumor cells since it ad infinitum synthesized IGFBP7. Meanwhile augmentation of IGFBP7 in cell supernatant would induce apoptosis of part of tumor cells and therefore, the synthesis of IGFBP7 also decreases with reduction of tumor cells. To determine therapeutic potential of pcDNA3.1-IGFBP7 in vitro, we analyzed cells viability and apoptosis rates by the Cell Counting Kit-8 and FCM. Our results are consistent with the research of Sprenger [13], which indicated that the growth of a tumorigenic SV40 prostate cell line, M12, was suppressed by transfecting the IGFBP-rP1 cDNA. Also, prostatic carcinoma cells were stably transfected with IGFBP7 cDNA and showed poor tumorigenicity [21]. Moreover, IGFBP7 which acts through autocrine/paracrine pathways to inhibit BRAF-MEK-ERK signaling and induce apoptosis [9], but it is contradictory to some researcher’s findings, as they indicated that IGFBP7 was highly overexpressed in glioma tissues, mediateing glioma cell growth, and migration [22]. In addition, the expression pattern of IGFBP7 varies with tumor types.