Background: Current therapies for multiple myeloma (MM) are associated with toxicity and resistance, highlighting the need for novel effective therapeutics. Berberine (BBR), a botanical alkaloid derived from several Berberis medicinal plants, has exhibited anti-tumor effects, including against multiple myeloma (MM); however, the molecular mechanism underlying the anti-MM effect has not been previously described. This study aimed to identify the target of berberine and related mechanisms involved in its therapeutic activity against MM. Results: Here, we demonstrated that BBR treatment killed MM cells in vitro and prolonged the survival of mice bearing MM xenografts in vivo. A screening approach integrating surface plasmon resonance (SPR) with liquid chromatography-tandem mass spectrometry (LC-MS/MS) identified UHRF1 (ubiquitin-like with PHD and RING Finger domains 1) as a potential target of BBR. Combining molecular docking and SPR analysis, we confirmed UHRF1 as a BBR-binding protein and discovered that BBR binds UHRF1 in the tandem tudor domain and plant homeodomain (TTD-PHD domain). BBR treatment induced UHRF1 degradation via the ubiquitin-dependent proteasome system and reactivated p16^INK4A and p73 in MM cells. Overexpression of UHRF1 promoted the MM cell proliferation and rendered MM cells more resistant to BBR, while silencing of UHRF1 with siRNA attenuated BBR-induced cytotoxicity. Conclusions: In summary, our study has identified UHRF1 as a direct target of BBR and uncovered molecular mechanisms involved in the anti-MM activity of BBR. Targeting UHRF1 through BBR may be a novel therapeutic strategy against MM.

The mechanism underlying the association between the development of head and neck squamous cell carcinoma (HNSCC) and ferroptosis is unclear. We analyzed the transcriptomes of 5902 single cells from a single-cell RNA-sequencing (scRNA-seq) dataset. They then aggregate into B cells, epithelial cells, fibroblasts, germ cells, mesenchymal cells, cancer stem cells, stem cells, T cells and endometrial cells, respectively. Our study shows that multiple pathways are significantly enriched in HNSCC development including extracellular matrix structural components, humoral immune responses, and muscle contraction. Differentially expressed genes analysis in Pseudotime analysis, pathway and biological function indicated that there was a significant correlation in the ferroptosis pathway. Furthermore, higher ferroptosis potential index (FPI) scores were significantly associated with worse overall survival prognosis in HNSCC patients. Pseudo-temporal, survival analyses and immunohistochemistry identified multiple central genes in HNSCC development, including ACSL1, SLC39A14, TFRC, and PRNP genes, and indicated associated ferroptosis. Overall, our study detected ferroptosis-related features is closely correlated with HNSCC prognosis and development, and deserved candidates suitable for immunotherapy treatment strategies determination for HNSCC patients.

Purpose: Imatinib, the breakpoint cluster region protein (BCR)/Abelson murine leukemia viral oncogene homolog (ABL) inhibitor, is widely used to treat chronic myeloid leukemia (CML). However, imatinib resistance develops in many patients. Therefore, new drugs with improved therapeutic effects are urgently needed. Berberine (BBR) is a potent BCR-ABL inhibitor for imatinib-sensitive and -resistant CML. Experimental Design: Protein structure analysis and virtual screening were used to identify BBR targets in CML. Molecular docking analysis, surface plasmon resonance imaging, nuclear magnetic resonance assays, and thermoshift assays were performed to confirm the BBR target. The change in BCR-ABL protein expression after BBR treatment was assessed by Western blotting. The effects of BBR were assessed in vitro in cell lines, in vivo in mice, and in human CML bone marrow cells as a potential strategy to overcome imatinib resistance. Results: We discovered that BBR bound to the protein tyrosine kinase domain of BCR-ABL. BBR inhibited the activity of BCR-ABL and BCR-ABL with the T315I mutation, and it also degraded these proteins via the autophagic lysosome pathway by recruiting E3 ubiquitin-protein ligase LRSAM1. BBR inhibited the cell viability and colony formation of CML cells and prolonged survival in CML mouse models with imatinib sensitivity and resistance. Conclusions: The results show that BBR directly binds to and degrades BCR-ABL and BCR-ABL T315I via the autophagic lysosome pathway by recruiting LRSAM1. The use of BBR is a new strategy to improve the treatment of patients with CML with imatinib sensitivity or resistance. See related commentary by Elf, p. 3899

MiR-181a is downregulated in leukemia and affects its progression, drug resistance, and prognosis. However, the exact mechanism of its targets in leukemia, particularly in chronic myelogenous leukemia (CML), has not previously been established. Here, we use a multi-omics approach to demonstrate that protein tyrosine phosphatase, receptor type, f polypeptide, leukocyte common antigen (LAR) interacting protein (liprin), alpha 1 (PPFIA1) is a direct target for miR-181a in CML. Phosphoarray assay shows that multiple phosphorylated proteins, particularly KIT signaling molecules, were downregulated in PPFIA1 inhibition. Additionally, PPFIA1 bound PARP1, a common molecule downstream of both PPFIA1 and BCR/ABL, to upregulate KIT protein through activation of nuclear factor kappa B (NF-kappa B)-P65 expression. Targeted inhibition of PPFIA1 and PARP1 downregulated c-KIT level, inhibited CML cell growth, and prolonged mouse survival. Overall, we report a critical regulatory miR-181a/PPFIA1/PARP1/NF-kappa B-P65/KIT axis in CML, and our preclinical study supports that targeted PPFIA1 and PARP1 may serve as a potential CML therapy.