Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer that lacks reliable targets for diagnosis and therapy. Non-coding RNA (ncRNA)-encoded products hold promise for addressing this unmet need. By analyzing the reported ribosomal RNA sequencing data, combined with the TCGA, ORFfinder, SmProt databases, we identified CDKN2B-AS1, a TNBC-upregulated lncRNA encoding a 66-amino-acid peptide via CUG-initiated translation. CRISPR-Cas9 gene editing and mass spectrometry confirmed endogenous expression of this peptide, designated 66CTG, in TNBC cells. Functionally independently of its host RNA, 66CTG promoted the proliferation of TNBC cells and the tumor growth of TNBC xenograft by stabilizing c-Myc protein and enhancing Cyclin D1 transcription. Immunohistochemistry of 89 clinical TNBC paraffin samples revealed positive correlations among 66CTG, c-Myc, and Cyclin D1 expression levels. Mechanistically, co-immunoprecipitation and ubiquitination assays revealed that 66CTG stabilized c-Myc by competitively interacting with FBW7α, an E3 ligase responsible for recognizing 66CTG CPDS56/S60 motif which phosphorylated by GSK-3β during the late G1 phase. In conclusion, our findings suggest 66CTG has potential to be developed as a target for TNBC diagnosis and therapy. Furthermore, it unveils a regulatory axis wherein 66CTG stabilizes c-Myc by interacting with FBW7α, offering a new mechanistic explanation for c-Myc overexpression in TNBC. Patients co-overexpressing 66CTG, c-Myc, and Cyclin D1 may benefit from therapies targeting this axis.

Ferroptosis induced by ferrous ions (Fe2+) and lipid peroxidation accumulation is a novel form of regulated cell death that has become a hot topic in tumor therapy research. Identifying small-molecule drugs that can induce ferroptosis in tumor cells is a very attractive therapeutic strategy. Here, we screened a natural product, acevaltrate (ACE), which rapidly and strongly induces ferroptosis in colorectal cancer cells. ACE not only increases Fe2+ levels in colorectal cancer cells by targeting iron chaperones PCBP1/2 and reducing their expression but also disrupts the antioxidant system of colorectal cancer cells by targeting GPX4 and inhibiting its enzymatic activity, leading to its ubiquitin-mediated degradation. This dual effect of ACE makes it significantly more effective than classical ferroptosis inducers in inducing ferroptosis. Our animal experiments revealed that the therapeutic effect of ACE surpasses that of established ferroptosis-inducing drugs and is superior to that of first-line clinical drugs such as capecitabine and TAS-102. Importantly, ACE also demonstrated superior inhibitory effects in colorectal tumor organoids versus at the cellular level, underscoring its potential for clinical application. This study pioneers the discovery of a small molecule inhibitor that targets both PCBP1/2 and GPX4, offering a novel therapeutic strategy for eliminating cancer cells through ferroptosis.Acevaltrate (ACE) was identified as a potent inducer of ferroptosis in colorectal cancer cells. ACE increases Fe2+ levels by targeting PCBP1/2 and disrupts the antioxidant system by inhibiting GPX4, leading to its degradation. This dual action makes ACE more effective at inducing ferroptosis than traditional inducers. Our study introduces ACE as the first small-molecule inhibitor of PCBP1/2 and GPX4, offering a new therapeutic approach for cancer cell elimination through ferroptosis

Simultaneously targeting key pathogenic drivers and remodeling of the tumor microenvironment represents a critical therapeutic strategy for relapsed or refractory (r/r) multiple myeloma (MM) and lymphoma. Purinostat mesylate (PM), a highly selective HDAC I/II binhibitor, exhibits excellent antitumor activity in MM and lymphoma cell lines and mouse models, outperforming the pan-HDAC inhibitor panobinostat or first-line/second-line multi-drug combinations. Different from panobinostat, bulk RNA-seq analysis revealed that PM suppressed essential tumor survival factors and triggered inflammation and interferon responses. The scRNA-seq of 5TMM models further indicated that PM enhanced antitumor immunity by boosting monocyte- and T cell-mediated immune responses. In a phase I trial (NCT05526313; N = 29) of PM at doses up to 15 mg/m², treatment-related Grade ≥3 adverse events predominantly comprised hematologic toxicities: thrombocytopenia (75.9%), neutropenia (55.2%), leukopenia (41.4%), and lymphopenia (31.0%), with no dose-limiting toxicities observed. PM monotherapy achieved a disease control rate of 72.7% (8/11) and an objective response rate (ORR) of 9.1% (1/11) in r/r MM. Notably, r/r lymphoma patients showed an ORR of 61.6% (11/18), particularly reaching 63.6% (7/11) with 6 complete responses in diffuse large B-cell lymphoma (DLBCL). Treatment responders exhibited enhanced immune activation, with elevated CD3+CD8+ T cells and increased cytokine levels, such as IFN-γ and CXCL10. Overall, PM is safe and moderately effective in MM, but highly effective in lymphoma. Additionally, PM combined with pomalidomide and dexamethasone showed strong synergistic activity in r/r MM treatment. These findings support further open-label, multicenter phase Ib/IIa trials of PM combination therapy with immunomodulators for r/r MM, as well as phase II monotherapy trials for r/r DLBCL and r/r T-cell lymphoma.

The -1 programmed ribosomal frameshifting (-1 PRF) in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is crucial for keeping the balance between pp1a and pp1ab polyproteins. To date, the host factors influencing this process remain poorly understood. Using RNA pull-down assays combined with mass spectrometry screening, we discovered five host proteins interacting with -1 PRF RNA, including Stem Loop Binding Protein (SLBP). Our findings revealed that SLBP overexpression enhanced frameshifting and promoted viral replication. Moreover, the interaction between SLBP and -1 PRF RNA was predicted using the PrismNet deep learning tool, which calculated a high binding probability of 0.922. Using Electrophoretic Mobility Shift Assays (EMSAs) and RNA pull down assays, our findings demonstrated SLBP’s direct binding to the SARS-CoV-2 genome, with preferential affinity for the stem loop 3 region of the -1 PRF RNA. Using smFISH assays, we further confirmed their physical colocalization. The role of SLBP in promoting frameshifting was verified using an in vitro translation system. Further investigation showed that SLBP deletions reshaped the host factor pattern around -1 PRF RNA, diminishing interactions with FUBP3 and RPS3A while enhancing RPL10A binding. Together, our findings identify SLBP as a host protein that promotes SARS-CoV-2 frameshifting, highlighting its potential as a druggable target for COVID-19.

Mitochondria are the energy production centers in cells and have unique genetic information. Due to the irreplaceable function of mitochondria, mitochondrial dysfunction often leads to pathological changes. Mitochondrial dysfunction induces an imbalance between oxidation and antioxidation, mitochondrial DNA (mtDNA) damage, mitochondrial dynamics dysregulation, and changes in mitophagy. It results in oxidative stress due to excessive reactive oxygen species (ROS) generation, which contributes to cell damage and death. Mitochondrial dysfunction can also trigger inflammation through the activation of damage-associated molecular patterns (DAMPs), inflammasomes and inflammatory cells. Besides, mitochondrial alterations in the functional regulation, energy metabolism and genetic stability accompany the aging process, and there has been a lot of evidence suggesting that oxidative stress and inflammation, both of which are associated with mitochondrial dysfunction, are predisposing factors of aging. Therefore, this review hypothesizes that mitochondria serve as central hubs regulating oxidative stress, inflammation, and aging, and their dysfunction contributes to various diseases, including cancers, cardiovascular diseases, neurodegenerative disorders, metabolic diseases, sepsis, ocular pathologies, liver diseases, and autoimmune conditions. Moreover, we outline therapies aimed at various mitochondrial dysfunctions, highlighting their performance in animal models and human trials. Additionally, we focus on the limitations of mitochondrial therapy in clinical applications, and discuss potential future research directions for mitochondrial therapy.

How the host immune system loses its surveillance function during the evolution from normal cell to malignancy is still largely unknown. Here, we investigate the dynamics changes of the pancreatic ductal adenocarcinoma (PDAC) tumor microenvironment by profiling 132,115 single-cell transcriptomes derived from 51 tissues, including healthy pancreatic tissue, non-metastatic PDAC primary tumors, metastatic primary tumors, and patient-matched liver metastases. The cellular proportion, bio-functional, and interaction between each cell type are carefully characterized. Aberrant copy number variations (CNVs) indicating malignant intensity are identified at chromosomes 7 and 20 of epithelial cells during tumor development. A bio-functional transition of predominant genes from physiology to pancreatic oncogenesis and metastasis is observed. Combinatorial analysis of epithelial cells and immunocytes indicates a gradient loss of immune surveillance during the malignant transformation. By dissecting cellular interaction, we unravel an incremental tumor cell-triggered apoptosis of DCs through molecular pair ANXA1-FPR1/3. Consequently, the activation and infiltration of cytotoxic CD8+ T cells are dampened progressively. Remarkably, we unveil a novel subtype of stress-response NK cells (strNK), which are characterized by robust proliferation, diminished cytolytic capabilities, and negative immune regulation. Notably, the presence of strNK cells is associated with poor prognosis of PDAC patients, implying a potential pro-tumor function. Taken together, our results not only shed light on the intricate mechanisms underlying step-wise evasion of immune surveillance during PDAC tumor development, but also provide a potential strategy for holding back malignant transition by reinforcing DCs’ function.