For newly diagnosed multiple myeloma (MM) patients, the primary treatment approaches include proteasome inhibitors such as bortezomib (BTZ), immunomodulatory drugs (IMiDs) such as lenalidomide, conventional chemotherapeutic agents such as adriamycin (doxorubicin, ADR), and others (Dimopoulos et al., 2025, Mafra et al., 2025). Despite the development of novel agents, MM remains incurable due to relapse and drug resistance following initial therapies. The marked intrinsic heterogeneity of MM significantly contributes to therapeutic failure through mechanisms such as target antigen loss and the development of multi-drug resistance, which often arise in patients receiving first-line regimens (Vo et al., 2022). Resistance involves multifactorial processes (Samur et al., 2023), including clonal genetic evolution (Poos et al., 2023), epigenetic reprogramming (Chong et al., 2023), dynamic crosstalk with the bone marrow microenvironment (Bishop et al., 2024), and adaptive immune escape pathways (Larrayoz et al., 2023). Dysregulation of transcription factors (TFs) disrupts downstream gene expression and induces cellular reprogramming, thereby promoting tumorigenesis and drug resistance. Aberrations in transcriptional networks involving Myc, cMAF, IRF4, and CREB1 are hallmarks of MM and are associated with adverse clinical outcomes and multi-drug resistance (Rahmat et al., 2024, Wang et al., 2024). Recent advances in therapeutic strategies, such as optimized CAR-T designs (Eckmann et al., 2025), RNA-based interventions (Oprea and Ionita, 2025), novel small-molecule inhibitors (Wen et al., 2025), and drug repurposing approaches (Hattori et al., 2025), have shown partial efficacy in overcoming drug resistance in MM. Therefore, identifying novel TF targets involved in MM pathogenesis and drug resistance remains crucial.

ADR, an anthracycline antibiotic, is a cell cycle non-specific broad-spectrum antitumor agent that intercalates into DNA double strands and inhibits topoisomerase II, leading to DNA damage (Bodley et al., 1989, Yu et al., 2023). Additionally, ADR can directly induce apoptosis (Liu et al., 2019), pyroptosis (Yin et al., 2024), autophagy (Matsunaga et al., 2019), and ferroptosis (Shen et al., 2024) to kill cancer cells. Apoptosis, a canonical form of programmed cell death, is primarily mediated through a caspase-dependent cascade that ultimately leads to cell death (Yuan and Ofengeim, 2024). Pyroptosis is a recently identified form of inflammatory cell death dependent on the N-terminal cleaved fragments of gasdermin (GSDM) family proteins. Typically, gasdermin D (GSDMD) is cleaved by inflammatory caspases (caspase-1, −4, or −5) (Shi et al., 2017), while gasdermin E (GSDME) is cleaved by caspase-3 (Wang et al., 2017). In MM, ADR has been reported to induce cardiomyocyte pyroptosis via GSDMD (Christidi and Brunham, 2021). However, the mechanisms underlying ADR-induced myeloma cell death remain poorly defined. Moreover, whether any novel TFs contribute to ADR resistance is not yet clear. Consequently, there is considerable interest in identifying novel regulators of ADR resistance and evaluating their clinical relevance in MM.

ADR resistance in tumors is largely attributed to enhanced drug efflux mediated by ATP-binding cassette (ABC) transporters such as ABCB1 (Lei et al., 2024) and ABCG2 (Turner et al., 2006). Recent studies have highlighted celastrol, a compound derived from Tripterygium Wilfordii Hook. L., which exhibits potent antitumor activity (Johrer and Ҫiҫek, 2021) and can overcome ADR resistance in several cancer cells (Kannaiyan et al., 2011), which may involve ABC transporters except in MM. To investigate the role of celastrol in MM, we employed FITC-labeled celastrol as a probe to screen for potential TF targets, as described in our previous work (Deng et al., 2025). This led to the identification of deformed epidermal autoregulatory factor-1 (DEAF1) as a potential mediator of MM cell proliferation and ADR resistance. DEAF1, a non-classical TF, is involved in embryonic development, immune regulation, neural signaling, and tumor progression (Nabais Sa et al., 2019). Previous studies have shown that DEAF1 promotes the proliferation of breast epithelial cells by binding to LIM-only protein 4 (LMO4), suggesting a possible role in breast carcinogenesis (Cubeddu et al., 2012, Gallardo-Blanco et al., 2025). DEAF1 also facilitates hepatocellular carcinoma progression by maintaining redox balance (Huang et al., 2025). Interestingly, DEAF1 deletion induces autophagy in muscle stem cells (Goh et al., 2024), indicating a potential role in regulating cell death processes. Nevertheless, the function of DEAF1 in MM, particularly in the context of drug resistance, remains largely unexplored. Our goal is to elucidate the role of DEAF1 in MM, especially in drug resistance.

In this study, we identified DEAF1 as a novel TF target of celastrol and sought to uncover its transcriptional regulatory role in MM cell proliferation and ADR-induced cell death. In parallel, we characterized the function of celastrol in MM, offering a promising therapeutic strategy for patients with ADR-resistant MM.