MMP-1 Over-expression Promotes Malignancy and Stem-Like Properties of Human Osteosarcoma MG-63 Cells In Vitro

Osteosarcoma is the most common primary malignant bone tumor in childhood,and it maintains a high level of recurrence.Matrix metalloproteinase-1(MMP-1)was found to contribute to cancer progression.The present study was to investigate the in vitro effects of MMP-1 over-expression on the proliferation,invasion,metastasis and stem-like properties of osteosarcoma MG-63 cells.The MG-63 cells were cultured and had a full length MMP-1 cDNA inserted by the tentiviral vector (MG-63^MMP-1+).MG-63 negative control and MG-63 blank control groups were established as well.MMP-1 expression was detected in MG-63^MMP-1+,MG-63 negative control and MG-63 blank control cells using qPCR,Western blotting and immunofluorescence after 24h of culture. The cell proliferation assay was performed with a camera attached to a bioreactor,which was programmed to photograph five regions of each well every 10 min over a period of 48 h.The cell invasion assay was conducted with Matrigel to assess the invasive potential,of MG-63 cells over 24h,the qPCR analysis to measure stem cell markers,including Oct4, Sox-2,Nanog,and Pax-7,and Western blot analysis to detect invasive and metastatic potential markers TIMP-1,VEGF and BMP2/4,after 24h of culture.Immunofluorescence was used to investigate the presence of the stem cell marker Pax-7 after 24-h culture. The results showed that over-expression of MMP-1 after transfection could significantly increase minor cell proliferation and invasion (P<0.05,MG-63^MMP-1+ versus controls).Pax-7 was highly expressed in MG-63^MMP-1+ cells,with no significant changes of Oct-4,Sox-2, and Nanog observed (P<0.05).MG-63^MMP-1+ cells showed higher expression of VEGF and BMP 2/4 proteins and lower expression of TIMP-1 protein than controls (P<0.05).It was concluded that MMP-1 over-expression in MG-63 cells contributed to the proliferation, invasion,metastasis and stem-like properties of osteosarcoma cells.Future studies should focus on in vivo effects of MMP-1 over-expression and the application of MMP-1 and Pax-7 inhibition in vivo to osteosarcoma theraoies.

Bismuth-based materials for rechargeable aqueous batteries and water desalination

Aqueous batteries and seawater desalination have received considerable attention in recent years due to their merits as high safety,environmental friendliness and cost-effectiveness.However,the scarcity of highly match electrode materials hinders their development.The exploration of high performance and low cost electrode materials is crucial for their potential applications.Bismuth(Bi),with high energy density and low redox potential,shows perspective in the field of aqueous batteries and seawater desalination,and significant progress has been achieved in the past decades.In this review,the unique properties and synthetic methods of Bi-based electrodes,as well as their applications are comprehensively summarized and discussed.The commonly used preparation methods of Bibased electrodes,including hydrothermal method,electrodeposition method,etc.,are introduced.Then,the applications of the Bi-based composites in aqueous batteries,such as Ni//Bi batteries and water desalination,are summarized.Finally,the challenges and future research direction of Bi-based materials are proposed.