Wnt/β-catenin regulates cellular functions related to tumor initiation and progression, cell proliferation, differ- entiation, survival, and adhesion, β-Catenin-independent Wnt pathways have been proposed to regulat...Wnt/β-catenin regulates cellular functions related to tumor initiation and progression, cell proliferation, differ- entiation, survival, and adhesion, β-Catenin-independent Wnt pathways have been proposed to regulate cell polarity and migration, including metastasis. In this review, we discuss the possible roles of both β-catenin-dependent and -independent signaling pathways in tumor progression, with an emphasis on their regulation of Rho-family GTPases, cytoskeletal remodeling, and relationships with cell-cell adhesion and cilia/ciliogenesis.展开更多
Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowinten...Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowintensity ultrasound stimulation on the proliferation and reproductivity of Hep G2 and 3T3 cells in vitro was examined with a 1.06 MHz-generator by changing the parameters(including intensity, pulse repetition frequency and duty cycle)in a wide range. Cell viability and reproductivity at different time after sonication were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and colony formation assay to indicate timerelated proliferation. The results illustrate that ultrasound irradiation at 0.4—0.8 W/cm^2 and high pulse repetition frequency(100 Hz)can facilitate cell proliferation, while above 0.8 W/cm^2 would resist it. The extent of resistance closely correlated with duty cycle and pulse repetition frequency. Resistance effect at low pulse repetition frequency(1 Hz)is greater than that at high pulse repetition frequency(100 Hz)and not time-related. The influence of high pulse repetition frequency is time-accumulated, indicating cellular process involved. These findings would provide valuable guidelines for the application of low-intensity ultrasound in stem cell transformation and tissue engineering.展开更多
Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the ...Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the fabricated alloys were systematically investigated. The results show that with different weight ratios of the space-holder (NH4- HC03) added, all of the porous Ti-10Mo alloys sintered at 1,300℃ exhibited a typical W idmanstatten microstructure. The porosity and average pore size of the porous structures can be controlled in the range of 50.8%-66.9% and 70.1 -381.4μm , respectively. The Ti-10Mo alloy with 63.4% porosity exhibited the most suitable mechanical properties for implant applications with an elastic modulus of 2.9 GPa and a compressive yield strength of 127.5 MPa. In vitro9 the alloyconditioned medium showed no deleterious effect on the cell proliferation. The cell viability in this medium was higher than that of the reference group, suggesting non-toxicity and good biological characteristics of the alloy specimens. In vivo, after eight weeks* implantation, new bone tissue formed surrounding the alloy implants, and no noticeable inflammation was observed at the implantation site. The bone bonding strength of the porous Ti-10Mo alloy increased over time from 46.6N at two weeks to 176.4 N at eight weeks. Suitable mechanical properties together with excellent biocompatibility in vitro and osteointegration in vivo make the porous Ti-10Mo fabricated by powder metallurgy an attractive orthopedic implant alloy.展开更多
文摘Wnt/β-catenin regulates cellular functions related to tumor initiation and progression, cell proliferation, differ- entiation, survival, and adhesion, β-Catenin-independent Wnt pathways have been proposed to regulate cell polarity and migration, including metastasis. In this review, we discuss the possible roles of both β-catenin-dependent and -independent signaling pathways in tumor progression, with an emphasis on their regulation of Rho-family GTPases, cytoskeletal remodeling, and relationships with cell-cell adhesion and cilia/ciliogenesis.
基金Supported by the Natural Science Foundation of Tianjin(No.12JCYBJC18300)
文摘Ultrasound has been widely used in clinics. Cellular responses to low-intensity ultrasound are parameter-dependent. Proper parameter setting is vital to its exact use. To get guidelines for parameter setting, lowintensity ultrasound stimulation on the proliferation and reproductivity of Hep G2 and 3T3 cells in vitro was examined with a 1.06 MHz-generator by changing the parameters(including intensity, pulse repetition frequency and duty cycle)in a wide range. Cell viability and reproductivity at different time after sonication were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)and colony formation assay to indicate timerelated proliferation. The results illustrate that ultrasound irradiation at 0.4—0.8 W/cm^2 and high pulse repetition frequency(100 Hz)can facilitate cell proliferation, while above 0.8 W/cm^2 would resist it. The extent of resistance closely correlated with duty cycle and pulse repetition frequency. Resistance effect at low pulse repetition frequency(1 Hz)is greater than that at high pulse repetition frequency(100 Hz)and not time-related. The influence of high pulse repetition frequency is time-accumulated, indicating cellular process involved. These findings would provide valuable guidelines for the application of low-intensity ultrasound in stem cell transformation and tissue engineering.
基金supported by the Fundamental Research Funds for the Central Universities (FRF-GF-17-B39)the financial support for this research by the National Health and Medical Research Council (NHMRC), Australia through project grant (GNT1087290)
文摘Porous Ti-lOMo alloys were fabricated by powder metallurgy using a space-holder method. The pore characteristics, m icrostructure, mechanical properties, in vitro biocompatibility, and in vivo osseointegration of the fabricated alloys were systematically investigated. The results show that with different weight ratios of the space-holder (NH4- HC03) added, all of the porous Ti-10Mo alloys sintered at 1,300℃ exhibited a typical W idmanstatten microstructure. The porosity and average pore size of the porous structures can be controlled in the range of 50.8%-66.9% and 70.1 -381.4μm , respectively. The Ti-10Mo alloy with 63.4% porosity exhibited the most suitable mechanical properties for implant applications with an elastic modulus of 2.9 GPa and a compressive yield strength of 127.5 MPa. In vitro9 the alloyconditioned medium showed no deleterious effect on the cell proliferation. The cell viability in this medium was higher than that of the reference group, suggesting non-toxicity and good biological characteristics of the alloy specimens. In vivo, after eight weeks* implantation, new bone tissue formed surrounding the alloy implants, and no noticeable inflammation was observed at the implantation site. The bone bonding strength of the porous Ti-10Mo alloy increased over time from 46.6N at two weeks to 176.4 N at eight weeks. Suitable mechanical properties together with excellent biocompatibility in vitro and osteointegration in vivo make the porous Ti-10Mo fabricated by powder metallurgy an attractive orthopedic implant alloy.
