RESUMEN
HuH-7 cells, derived from human hepatocarcinoma, are known to contain the CD133-positive cancer stem cell populations. HuH-7 cells showed higher ATP synthesis activity through the respiratory chain compared to another human hepatocarcinoma cell line HepG2 and showed an especially higher glycerol-3-phosphate (G3P)-driven ATP synthesis (G3P-ATPase) activity. We found that the CD133-positive HuH-7 cells expressed high levels of GPD2 (glycerol-3-phosphate dehydrogenase or mGPDH) and showed high G3P-ATPase activity. Next, to elucidate the relationship between CD133 and GPD2, we inhibited downstream factors of CD133 and found that a p38 inhibitor decreased the expression of GPD2 and decreased the G3P-ATPase activity. Furthermore, GPD2-knockdown (GPD2-KD) cells exhibited strong reduction of the G3P-ATPase activity and reduction of lactic acid secretion. Finally, we validated the effect of GPD2-KD on tumorigenicity. GPD2-KD cells were found to show decreased anchorage-independent cell proliferation, suggesting the linkage of G3P-ATPase activity to the tumorigenicity of the CD133-positive HuH-7 cells. Inhibition of G3P-ATPase disrupts the homeostasis of energy metabolism and blocks cancer development and progression. Our results suggest inhibitors, targeting GPD2 may be potential new anticancer agents.
Asunto(s)
Transporte de Electrón/fisiología , Metabolismo Energético/fisiología , Glicerolfosfato Deshidrogenasa/metabolismo , Neoplasias Hepáticas/metabolismo , Mitocondrias/metabolismo , Membranas Mitocondriales/metabolismo , Antígeno AC133/genética , Antígeno AC133/metabolismo , Adenosina Trifosfato/metabolismo , Carcinoma Hepatocelular/metabolismo , Línea Celular , Transporte de Electrón/genética , Metabolismo Energético/genética , Técnicas de Silenciamiento del Gen , Técnicas de Transferencia de Gen , Glicerolfosfato Deshidrogenasa/genética , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Mitocondrias/genética , NAD/metabolismo , TranscriptomaRESUMEN
Avian influenza viruses easily spread allowing viral re-assortment to simply occur which in-turn increases the potential for a pandemic. A novel 2013 H5N6 influenza strain was detected among the avian population and was reported to continuously evolve, however, this was never structurally demonstrated. Here, we elucidated the putative structural evolution of the novel H5N6 influenza strain. Throughout this study, we analyzed 2013-2017 H5N6 HA protein models. Model quality was first verified before further analyses and structural comparison was made using superimposition. We found that Leu was inserted at position 1291 among the 2013-2015 models while Leu was not inserted among the 2016-2017 models. Moreover, presence of Leu at position 1291 shifts residue E1261 by 159.6° affecting nearby residues which may explain the difference between the 2013-2015 and 2016-2017 HA structural groups. Similarly, we believe that our results would support the hypothesis that the current H5N6 strain is still continuously evolving.