Y-box binding protein-1 (YB-1) is a pleiotropic molecule that binds DNA to regulate genes on a transcriptional level in the nucleus and binds RNA to modulate gene translation in the cytoplasm. In our previous studies, YB-1 was also characterized as a fetal hepatic protein that regulates the maturation of hepatocytes and is upregulated during liver regeneration. Moreover, YB-1 has been shown to be expressed in human hepatocellular carcinoma (HCC). However, the role of YB-1 in HCC remains unclear. Here, we aimed to characterize the role of YB-1 in HCC. Based on the results of loss-of-function in HCC and gain-of-function in mice liver using hydrodynamic gene delivery, YB-1 promoted hepatic cells proliferation in vitro and in vivo. YB-1 was also involved in HCC cell proliferation, migration, and drug-resistance. The results of extreme limiting dilution sphere forming analysis and cancer initiating cell marker analysis were also shown that YB-1 maintained HCC initiating cells population. YB-1 also induced the epithelial-mesenchymal transition and stemness-related gene expression. Knockdown of YB-1 suppressed the expression of Wnt ligands and β-catenin, impaired Wnt/β-catenin signaling pathway and reduced the numbers of HCC initiating cells. Moreover, YB-1 displayed nuclear localization particularly in the HCC initiating cells, the EpCAM+ cells or sphere cells. Our findings suggested that YB-1 was a key factor in HCC tumorigenesis and maintained the HCC initiating cell population.

Over the last 2 decades, omalizumab is the only anti-IgE antibody that has been approved for asthma and chronic spontaneous urticaria (CSU). Ligelizumab, a higher-affinity anti-IgE mAb and the only rival viable candidate in late-stage clinical trials, showed anti-CSU efficacy superior to that of omalizumab in phase IIb but not in phase III. This report features the antigenic-functional characteristics of UB-221, an anti-IgE mAb of a newer class that is distinct from omalizumab and ligelizumab. UB-221, in free form, bound abundantly to CD23-occupied IgE and, in oligomeric mAb-IgE complex forms, freely engaged CD23, while ligelizumab reacted limitedly and omalizumab stayed inert toward CD23; these observations are consistent with UB-221 outperforming ligelizumab and omalizumab in CD23-mediated downregulation of IgE production. UB-221 bound IgE with a strong affinity to prevent FcԑRI-mediated basophil activation and degranulation, exhibiting superior IgE-neutralizing activity to that of omalizumab. UB-221 and ligelizumab bound cellular IgE and effectively neutralized IgE in sera of patients with atopic dermatitis with equal strength, while omalizumab lagged behind. A single UB-221 dose administered to cynomolgus macaques and human IgE (ε, κ)–knockin mice could induce rapid, pronounced serum-IgE reduction. A single UB-221 dose administered to patients with CSU in a first-in-human trial exhibited durable disease symptom relief in parallel with a rapid reduction in serum free-IgE level.