Contributions
Abstract: EP957
Type: E-Poster Presentation
Session title: Myeloma and other monoclonal gammopathies - Biology & Translational Research
Background
Multiple myeloma (MM) represents approximately 10 % of all blood tumors, which is characterized by abnormally uncontrolled clonal expansion of malignant plasma cells within the bone marrow. Despite advances in multimodal treatment regiments, it remains an incurable and fatal malignancy. Obesity has been implicated as a risk factor in multiple myeloma, but the specific biologic mechanisms have not yet been fully elucidated. As is reported, obesity might in part mediate its effects on myeloma cells via interaction with adipokines. Adiponectin is one of the most abundant and well-understood adipokines, and has been implicated as a protective character in the development of MM, according to its potent role in insulin-sensitizing, anti-lipotoxic, anti-apoptotic and anti-inflammatory properties. Hypoadiponectin was correlated with an increased risk in MM and in vitro study has confirmed that adiponectin could induce anti-proliferation and pro-apoptosis in MM cells, suggesting a promising therapeutic target in MM. However, the complex quaternary structure and rapid turnover may add to the difficulty in converting adiponectin to an applicable drug form, which pose a limitation in the use of adiponectin. AdipoRon was capable of binding and activating both adiponectin receptor 1(AdipoR1) and adiponectin receptor 2(AdipoR2) at a low micromolar concentration. Nevertheless, there is little data focusing on the roles of AdipoRon in MM cells.
Aims
To investigate the effects of AdipoRon on MM cells and the potential functional and molecular mechanisms.
Methods
We use the small-molecule agonist, AdipoRon, to treat the two MM cell lines: U266 and RPMI8226. The cell proliferation was detected by CCK-8. The early apoptosis and cell cycle were analyzed by flow cytometry. A real-time quantitative(RT-PCR) and western blot were used to determine the transcript and protein levels of potential signaling pathways.
Results
The western blot assay showed that both AdipoR1 and AdipoR2 were available in the two cell lines. The CCK-8 test indicated that AdipoRon significantly reduced the proliferation of MM cells with an increase concentration at a certain range. Moreover, at the same concentration, AdipoRon gradually suppressed the proliferation of MM cells with prolongation of exposure time. Flow cytometry results showed both the U266 and RPMI8226 cells were arrested in the G0/G1 phase and with fewer cells present in the S phase. Additionally, AdipoRon promoted apoptosis in the U266 and RPMI8226 cells, with up-regulation of cleaved-PARP and cleaved-Caspase-3. Molecular analysis further demonstrated that the phosphorylation of AMPK was strengthened gradually in AdipoRon-treated MM cells over time, while the phosphorylation of ACC decreased. Moreover, we found that CPT1A and ACC2 were up-regulated in AdipoRon-treated U266 cells.
Conclusion
Our results demonstrated that the adiponectin receptor agonist, AdipoRon, suppressed the proliferation, induced apoptosis and cell arrest in U266 and RPMI8226 cells in a time- and dose- manner, possibly via regulation of AMPK/ACC pathway. Additionally, the abnormal up-regulation of metabolism-related gene ACC2 and CPT1A suggested that an imbalance of energy metabolism might participated in the regulation of AdipoRon on MM cells.
Keyword(s): Apoptosis, Multiple myeloma, Proliferation, Signaling molecules
Abstract: EP957
Type: E-Poster Presentation
Session title: Myeloma and other monoclonal gammopathies - Biology & Translational Research
Background
Multiple myeloma (MM) represents approximately 10 % of all blood tumors, which is characterized by abnormally uncontrolled clonal expansion of malignant plasma cells within the bone marrow. Despite advances in multimodal treatment regiments, it remains an incurable and fatal malignancy. Obesity has been implicated as a risk factor in multiple myeloma, but the specific biologic mechanisms have not yet been fully elucidated. As is reported, obesity might in part mediate its effects on myeloma cells via interaction with adipokines. Adiponectin is one of the most abundant and well-understood adipokines, and has been implicated as a protective character in the development of MM, according to its potent role in insulin-sensitizing, anti-lipotoxic, anti-apoptotic and anti-inflammatory properties. Hypoadiponectin was correlated with an increased risk in MM and in vitro study has confirmed that adiponectin could induce anti-proliferation and pro-apoptosis in MM cells, suggesting a promising therapeutic target in MM. However, the complex quaternary structure and rapid turnover may add to the difficulty in converting adiponectin to an applicable drug form, which pose a limitation in the use of adiponectin. AdipoRon was capable of binding and activating both adiponectin receptor 1(AdipoR1) and adiponectin receptor 2(AdipoR2) at a low micromolar concentration. Nevertheless, there is little data focusing on the roles of AdipoRon in MM cells.
Aims
To investigate the effects of AdipoRon on MM cells and the potential functional and molecular mechanisms.
Methods
We use the small-molecule agonist, AdipoRon, to treat the two MM cell lines: U266 and RPMI8226. The cell proliferation was detected by CCK-8. The early apoptosis and cell cycle were analyzed by flow cytometry. A real-time quantitative(RT-PCR) and western blot were used to determine the transcript and protein levels of potential signaling pathways.
Results
The western blot assay showed that both AdipoR1 and AdipoR2 were available in the two cell lines. The CCK-8 test indicated that AdipoRon significantly reduced the proliferation of MM cells with an increase concentration at a certain range. Moreover, at the same concentration, AdipoRon gradually suppressed the proliferation of MM cells with prolongation of exposure time. Flow cytometry results showed both the U266 and RPMI8226 cells were arrested in the G0/G1 phase and with fewer cells present in the S phase. Additionally, AdipoRon promoted apoptosis in the U266 and RPMI8226 cells, with up-regulation of cleaved-PARP and cleaved-Caspase-3. Molecular analysis further demonstrated that the phosphorylation of AMPK was strengthened gradually in AdipoRon-treated MM cells over time, while the phosphorylation of ACC decreased. Moreover, we found that CPT1A and ACC2 were up-regulated in AdipoRon-treated U266 cells.
Conclusion
Our results demonstrated that the adiponectin receptor agonist, AdipoRon, suppressed the proliferation, induced apoptosis and cell arrest in U266 and RPMI8226 cells in a time- and dose- manner, possibly via regulation of AMPK/ACC pathway. Additionally, the abnormal up-regulation of metabolism-related gene ACC2 and CPT1A suggested that an imbalance of energy metabolism might participated in the regulation of AdipoRon on MM cells.
Keyword(s): Apoptosis, Multiple myeloma, Proliferation, Signaling molecules