Fig. 7

The effects of shrimp miR-965 on tumorigenesis of MSLC in vivo. a A flow diagram of the in vivo experiments. b The influence of shrimp miR-965 on tumors of lung tissue in mice. The MSLC were injected into nude mice, followed by treatment with shrimp miR-965 or shrimp miR-965-scrambled (control miRNA). Eight weeks after the first miRNA injection, the mice were sacrificed and the tumors of lung tissue were examined. The arrows indicated the tumors in lung tissues (upper panel). H&E staining for the lung biopsies of mice treated with shrimp miR-965 or shrimp miR-965-scrambled (control miRNA) (lower panel). c Mice were injected with non-MSLC for 8 weeks followed by examining the mouse lungs; upper panel indicated the mouse lungs, and the lower panel demonstrated the H&E staining results for lung biopsies from the non-MSLC-injected mice. d The detection of shrimp miR-965 in tumors of lung tissue. Northern blots were used to detect the levels of shrimp miR-965 in tumors in lung tissue of mice treated with shrimp miR-965 or control miRNA. e The detection of MCL expression. Western blots were used to detect protein levels of MCL-1 in tumors of mice treated with shrimp miR-965 or control miRNA. f The schematic presentation of shrimp miR-965 on the regulation of melanoma stem-like cell stemness. In normal condition (left panel), ER stress is negatively regulated by MCL-1; in detail, when ER stress is induced, XBP1 is spliced and then binds with MCL-1 promoter, thus activating the MCL-1 transcription; the increase of MCL-1 expression inhibits the ER stress in verse, which keeps the ER stress at a suitable level. When the shrimp miR-965 is introduced (right panel), MCL-1 is knocked down and the MCL-1-ER stress-XBP1 feedback loop is disrupted, which leads to the relief of ER stress inhibition and accumulation of ER stress. What is more, the accumulation of ER stress, on one hand, causes stemness loss, and on the other hand, enhances the Caspase 3/7 activity, thus triggering cell apoptosis. Meanwhile, cell viability decreased during ER stress accumulation