MicroRNAs (miRNAs) are small, non-coding RNAs that can serve as tumor suppressor genes or oncogenes in tumorigenesis. More and more evidence demonstrate that abnormal expression of miRNAs lead to the gastric carcinoma occurrence. In the present study, we revealed that the expression levels of miR-520f were significantly down-regulated in gastric carcinoma cells and clinical gastric carcinoma samples. Next, we demonstrated that introduction of miR-520f inhibited the growth of gastric carcinoma cells in vitro. However, down-regulate the expression levels of miR-520f by anti-miR-520f lead to an enhanced cell proliferation, implying that miR-520f maybe serve as a novel tumor suppressor. Moreover, we found that ATPase family AAA domain-containing protein 2 (ATAD2) was one target genes of miR-520f downstream regulator, which caused the decreased expression of ATAD2. Meanwhile, the overexpression of ATAD2 reversed the inhibited proliferation ability caused by miR-520f. Therefore, our find that miR-520f involves in gastric carcinoma proliferation, pointing a therapeutic probability of miR-520f in the therapy of gastric carcinoma.

Exposure to chronic stress induces anxiety-like behavior and metabolic changes in animals, resulting in adaptive or maladaptive responses to the stressful environment. Recent studies have indicated the dorsomedial ventromedial hypothalamus (dmVMH) as an important hub that regulates both anxiety and energy homeostasis. However, up to now, how dmVMH neurons exert dual control of chronic stress-induced anxiety and energy expenditure remains poorly understood. Here, we established a chronic-stress mouse model that induced anxiety-like behavior, reduced food consumption, and decreased energy expenditure. We found that c-fos expression increased and theta band power is higher in the dmVMH after chronic stress, and the proportion of burst firing neurons significantly increased, which was mediated by elevated expression of T-type calcium channel Cav 3.1. Optogenetically evoked burst firing of dmVMH neurons induced anxiety-like behavior, shifted the respiratory exchange ratio toward fat oxidation, and decreased food intake, while knockdown of Cav3.1 in the dmVMH had the opposite effects. Collectively, our study first revealed an important role of dmVMH burst firing in the dual regulation of anxiety-like behavior and energy expenditure, and identified Cav 3.1 as a crucial regulator of the activity of the burst firing neurons in dmVMH. These molecular and cellular level findings will advance our understanding of the chronic stress-induced emotional malfunction and energy expenditure disorders.