[Adiponectin Receptor Agonist AdipoRon Inhibits the Proliferation of Myeloma Cells via the AMPK/Autophagy Pathway]

Abstract

Objective: To investigate the inhibitory effect of adiponectin receptor agonist AdipoRon on proliferation of myeloma cell lines and its possible mechanism.

Methods: The myeloma cell lines Sp2/0-Ag14 and MPC-11 were treated with different concentration of AdipoRon. The cell proliferation was detected by CCK-8. Western blot was used to determine the protein level of the signaling pathway. RT-PCR was used to quantify the mRNA copy number of adiponectin receptor AdipoR1 and AdipoR2 in the bone marrow cells from 21 patients with multiple myeloma (MM). Twenty-three normal bone marrow samples were served as control.

Results: AdipoRon significantly inhibited the proliferation of MM cell lines Sp2/0-Ag14 and MPC-11 in a concentration-dependent and time-dependent manner. Western blot showed that AdipoRon induced an increase of the expression levels of apoptosis-related proteins cleaved caspase-3 and cleaved PARP. AdipoRon upregulated p-AMPK and its downstream p-ACC in MPC-11. In addition, AdipoRon upregulated LC3-II/LC3-I level and down-regulated the protein level of p62. The expression level of AdipoR1 in MM cells was significantly higher than that in normal controls, and the expression level of AdipoR2 in MM cells was significantly lower than that in normal controls.

Conclusion: Adiponectin receptors are expressed differentially between MM patients and normal subjects. AdipoRon, an adiponectin receptor agonist, can inhibit myeloma cell proliferation and induce apoptosis, and AMPK/autophagy pathway may be one of its mechanisms.