Galectin-12 is a member of an animal lectin family with affinity for β-galactosides and containing consensus amino acid sequences. Here, we found that galectin-12 was expressed in macrophages and thus aimed to determine how galectin-12 affects inflammation and macrophage polarization and activation. The ablation of galectin-12 did not affect bone marrow cells to differentiate into macrophages, but reduced phagocytic activity against Escherichia coli and lowered the secretion of nitric oxide. The ablation of galectin-12 also resulted in the polarization of macrophages into the M2 direction, as indicated by increases in the levels of M2 markers, namely, resistin-like β (FIZZ1) and chitinase 3-like 3 (Ym1), as well as a reduction in the expression levels of a number of M1 pro-inflammatory cytokines. We found that the diminished expression of pro-inflammatory cytokines in macrophages resulting from galectin-12 deletion was due to reduced activation of IKKα/β, Akt and ERK, which in turn caused decreased activation of NF-κB and activator protein 1. The activation of STAT3 was much higher in Gal12(-/-) macrophages activated by lipopolysaccharide, which was correlated with higher levels of IL-10. Adipocytes showed higher insulin sensitivity when treated with Gal12(-/-) macrophage-conditioned media than those treated with Gal12(+/+) macrophages. We conclude galectin-12 negatively regulates macrophage polarization into the M2 population, resulting in enhanced inflammatory responses and also in turn causing decreased insulin sensitivity in adipocytes. This has implications in the treatment of a wide spectrum of metabolic disorders.

GW182 binds to Argonaute (AGO) proteins and has a central role in miRNA-mediated gene silencing. Using lentiviral shRNAinduced GW182 knockdown in HEK293 cells, this study identifies a new role of GW182 in regulating miRNA stability. Stably knocking down GW182 or its paralogue TNRC6B reduces transfected miRNA-mimic half-lives. Replenishment of GW182 family proteins, as well as one of its domain D12, significantly restores the stability of transfected miRNA-mimic. GW182 knockdown reduces miRNA secretion via secretory exosomes. Targeted siRNA screening identifies a 3 0 -5 0 exoribonuclease complex responsible for the miRNA degradation only when GW182 is knocked down. Immunoprecipitation further confirms that the presence of GW182 in the RISC complex is critical in protecting Argonaute-bound miRNA.

Background: Among gynecological cancers, ovarian carcinoma has the highest mortality rate, and chemoresistance is highly prevalent in this cancer. Therefore, novel strategies are required to improve its poor prognosis. Formation and disassembly of focal adhesions are regulated dynamically during cell migration, which plays an essential role in cancer metastasis. Metastasis is intricately linked with resistance to chemotherapy, but the molecular basis for this link is unknown. Methods: Transwell migration and wound healing migration assays were used to analyze the migration ability of ovarian cancer cells. Real-time recordings by total internal reflection fluorescence microscope (TIRFM) were performed to assess the turnover of focal adhesions with fluorescence protein-tagged focal adhesion molecules. SOCE inhibitors were used to verify the effects of SOCE on focal adhesion dynamics, cell migration, and chemoresistance in chemoresistant cells. Results: We found that mesenchymal-like chemoresistant IGROV1 ovarian cancer cells have higher migration properties because of their rapid regulation of focal adhesion dynamics through FAK, paxillin, vinculin, and talin. Focal adhesions in chemoresistant cells, they were smaller and exhibited strong adhesive force, which caused the cells to migrate rapidly. Store-operated Ca 2+ entry (SOCE) regulates focal adhesion turnover, and cell polarization and migration. Herein, we compared SOCE upregulation in chemoresistant ovarian cancer cells to its parental cells. SOCE inhibitors attenuated the assembly and disassembly of focal adhesions significantly. Results of wound healing and transwell assays revealed that SOCE inhibitors decreased chemoresistant cell migration. Additionally, SOCE inhibitors combined with chemotherapeutic drugs could reverse ovarian cancer drug resistance. Conclusion: Our findings describe the role of SOCE in chemoresistance-mediated focal adhesion turnover, cell migration, and viability. Consequently, SOCE might be a promising therapeutic target in epithelial ovarian cancer.

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