Eukaryotic initiation factor subunit c(eIF3c) has been identified as an oncogene that is over-expressed in tumor cells and,therefore,is a potential therapeutic target for gene-based cancer treatment.This study was foc...Eukaryotic initiation factor subunit c(eIF3c) has been identified as an oncogene that is over-expressed in tumor cells and,therefore,is a potential therapeutic target for gene-based cancer treatment.This study was focused on investigating the effect of small interfering RNA(siRNA)-mediated eIF3c gene knockdown on colon cancer cell survival.The eIF3c gene was observed to be highly expressed in colon cancer cell models.The expression levels of the gene in eIF3c siRNA infected and control siRNA infected cells were compared via real-time polymerase chain reaction(PCR) and western blotting analysis.Cell proliferation levels were analyzed employing 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium bromide(MTT) and colony formation assays.Furthermore,the effects of eIF3c gene knockdown on the cell cycle and apoptosis were analyzed using flow cytometry.The results showed that suppression of eIF3c expression significantly(P<0.001) reduced cell proliferation and colony formation of RKO colon cancer cells.The cell cycle was arrested by decreasing the number of cells entering S phase.Further,apoptosis was induced as a result of eIF3c knockdown.Collectively,eIF3c deletion effectively reduced the survival of colon cancer cells and could be used as a therapeutic tool for colon cancer therapy.展开更多
Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in an...Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-a based on viral 2 Apro-mediated reduction of the interferon-alpha receptor 1(IFNAR1);however, the mechanism remains unknown. Here, we showed a significant increase in IFNAR1 protein induced by IFN-a in RD cells, whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-a signaling. Subsequently, we observed that EV-A71 2 Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4 GI(eIF4GI), without affecting IFNAR1 m RNA levels induced by IFN-a. The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved e IF4 GI. Importantly, we verified that 2 Aprocould activate cellular caspase-3, which was subsequently involved in e IF4 GI cleavage mediated by 2 Apro. Furthermore, inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2 A or infected with EV-A71, suggesting the pivotal role of both viral 2 Aproand caspase-3 activation in the disturbance of IFN-a signaling. Collectively, we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2 Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection, indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-a.展开更多
文摘Eukaryotic initiation factor subunit c(eIF3c) has been identified as an oncogene that is over-expressed in tumor cells and,therefore,is a potential therapeutic target for gene-based cancer treatment.This study was focused on investigating the effect of small interfering RNA(siRNA)-mediated eIF3c gene knockdown on colon cancer cell survival.The eIF3c gene was observed to be highly expressed in colon cancer cell models.The expression levels of the gene in eIF3c siRNA infected and control siRNA infected cells were compared via real-time polymerase chain reaction(PCR) and western blotting analysis.Cell proliferation levels were analyzed employing 3-(4,5-dimethylthiazol 2-yl)-2,5-diphenyltetrazolium bromide(MTT) and colony formation assays.Furthermore,the effects of eIF3c gene knockdown on the cell cycle and apoptosis were analyzed using flow cytometry.The results showed that suppression of eIF3c expression significantly(P<0.001) reduced cell proliferation and colony formation of RKO colon cancer cells.The cell cycle was arrested by decreasing the number of cells entering S phase.Further,apoptosis was induced as a result of eIF3c knockdown.Collectively,eIF3c deletion effectively reduced the survival of colon cancer cells and could be used as a therapeutic tool for colon cancer therapy.
基金grants from Beijing Natural Science Foundation(No.19G10290)National Natural Science Foundation of China(No.81772184).
文摘Enterovirus A71(EV-A71) is the major pathogen responsible for the severe hand, foot and mouth disease worldwide, for which few effective antiviral drugs are presently available. Interferon-a(IFN-a) has been used in antiviral therapy for decades;it has been reported that EV-A71 antagonizes the antiviral activity of IFN-a based on viral 2 Apro-mediated reduction of the interferon-alpha receptor 1(IFNAR1);however, the mechanism remains unknown. Here, we showed a significant increase in IFNAR1 protein induced by IFN-a in RD cells, whereas EV-A71 infection caused obvious downregulation of the IFNAR1 protein and blockage of IFN-a signaling. Subsequently, we observed that EV-A71 2 Apro inhibited IFNAR1 translation by cleavage of the eukaryotic initiation factor 4 GI(eIF4GI), without affecting IFNAR1 m RNA levels induced by IFN-a. The inhibition of IFNAR1 translation also occurred in puromycin-induced apoptotic cells when caspase-3 cleaved e IF4 GI. Importantly, we verified that 2 Aprocould activate cellular caspase-3, which was subsequently involved in e IF4 GI cleavage mediated by 2 Apro. Furthermore, inhibition of caspase-3 activation resulted in the partial restoration of IFNAR1 in cells transfected with 2 A or infected with EV-A71, suggesting the pivotal role of both viral 2 Aproand caspase-3 activation in the disturbance of IFN-a signaling. Collectively, we elucidate a novel mechanism by which cellular caspase-3 contributes to viral 2 Apro-mediated down-regulation of IFNAR1 at the translation level during EV-A71 infection, indicating that caspase-3 inhibition could be a potential complementary strategy to improve clinical anti-EV-A71 therapy with IFN-a.
