The transcriptional cofactors YAP1 and TAZ regulate target gene expression by binding to the transcription factor TEAD. Due to their roles in cancer initiation, progression, and drug resistance, YAP1 and TAZ are promising targets for cancer therapy. SAMD4A/B are RNA-binding proteins that are broadly expressed across human tissues, but few of their molecular targets and biological functions have been identified. In Drosophila, the SAMD4A/B homolog Smaug participates in early embryonic development by disrupting the stability and translation of maternal mRNA. To discover targets inhibiting the YAP1/TAZ-TEAD oncogenic transcription program, we screened a whole-genome siRNA library and identified siSAMD4B as potently suppressing TEAD activity in human cancer cells. We showed that SAMD4A/B increased TEAD activity by destabilizing and repressing the translation of VGLL4 mRNA, promoting cancer progression in vitro. Conversely, inhibiting either SAMD4A or SAMD4B elevated VGLL4 mRNA, which suppressed TEAD activity and inhibited cancer progression. Notably, transgenic mice expressing liver-specific SAMD4B exhibited accelerated development of intrahepatic cholangiocarcinomas in an Nf2-deficient background. These tumors appeared in the mutants at one week of age and caused death due to hepatic failure by 100 days. Thus, SAMD4A/B may be a promising target for anticancer drugs designed to inhibit TEAD activation.

Dysregulation of transfer RNA (tRNA) modification and reprogramming of codon-biased translation are commonly associated with cancer initiation and progression. However, their roles in chemoresistance and tumor recurrence remain poorly understood, especially in glioblastoma (GBM). This study establishes the tRNA-modifying enzyme YrdC N6-Threonylcarbamoyltransferase Domain Containing (YRDC) as a key mediator of temozolomide (TMZ) resistance in GBM. YRDC catalyzes the formation of N6-threonylcarbamoyladenosine (t6A) on ANN-decoding tRNAs (A denotes adenosine, and N denotes any nucleotide). YRDC expression is elevated in TMZ-resistant models and recurrent GBM, correlating with poor patient prognosis. Mechanistically, YRDC drives ANN codon-biased translation of target mRNAs, most notably encoding the fatty acid-binding protein FABP7. Elevated FABP7 induces lipid droplet accumulation, which sequesters TMZ-induced reactive oxygen species to mitigate oxidative stress and confer chemoresistance. Targeting this axis, we developed HY-Q66655, a novel blood-brain-barrier-penetrant YRDC inhibitor identified via virtual screening. HY-Q66655 directly inhibits YRDC, suppresses FABP7 translation, depletes lipid droplets, and acts synergistically with TMZ to inhibit tumor growth in vitro and in patient-derived orthotopic xenografts. The YRDC/FABP7 pathway is clinically associated with GBM recurrence, and HY-Q66655 demonstrates broad-spectrum anti-tumor activity across malignancies, revealing a tRNA modification-dependent mechanism and a potential therapeutic strategy.

Utilizing CAR-T cells to eliminate circulating tumor cells (CTCs) and inhibit metastasis is a promising strategy. However, this approach is hindered by the lack of specific antigens. Membrane-bound HSP70 (mHSP70) is commonly expressed on the cell membrane of numerous tumor types, notably on CTCs, making it an ideal target for CAR-T therapy to treat these malignancies and prevent metastasis. Here, we generated CAR T cells based on natural ligand granzyme B (GrB-CAR T) targeting mHSP70. GrB-CAR T cells exhibited potent cytotoxicity against a broad spectrum of cancer cell lines and stem-like cancer cells in vitro and effectively inhibited xenograft tumor growth in vivo. Importantly, CTCs maintain mHSP70 expression in xenograft models, and GrB-CAR T cells markedly decreased the number of CTCs, thereby preventing cancer metastasis. Moreover, despite human granzyme B exhibits cross-reactivity with mouse and macaque mHSP70-particularly given the complete homology between macaque and human mHSP70-no obvious adverse effects were observed in the animals treated with GrB-CAR T cells. These results demonstrate GrB-CAR T cells as a safe and effective approach with broad-spectrum anticancer activity and provide compelling experimental evidence for CAR T cell-mediated metastasis inhibition through targeting CTCs.

Protein S-palmitoylation, a dynamic lipid modification, is essential for protein stability, trafficking, and signaling; dysregulated palmitoyltransferases drive cancer, yet systematic discovery of palmitoyltransferases remains hindered by labor-intensive, motif-dependent assays. We present iPalmT, an end-to-end deep learning framework that identifies palmitoyltransferases directly from primary amino acid sequence without handcrafted features or prior domain annotations. The model combines convolutional layers and squeeze-and-excitation mechanisms to capture local sequence signals and long-range dependencies. On an independent test set, iPalmT achieved 0.99 accuracy, 0.98 precision, 0.97 recall, and 0.98 F1 score. Integrated Gradients attribution emphasized the canonical DHHC motif and highlighted additional putative functional domains, despite receiving no motif supervision. Proteome-scale application to human sequences yielded unreviewed candidates; two (A0A0D9SEX5 and A0A1W2PRJ8) underwent structural analysis and experimental validation, which supported the predictions. We further release a large predicted palmitoyltransferase resource comprising 10,365,644 sequences identified from 147,847,003 proteins across 33,285 species-level groups to support large-scale exploration and cross-species analyses. iPalmT is available as a standalone program ( https://github.com/Tengda-Li-Lab/iPalmT.git ), offering a scalable, sequence-only route to discover noncanonical, evolutionarily divergent palmitoyltransferases.

Immune checkpoint blockade (ICB) has shown substantial efficacy in microsatellite instability-high (MSI-H) colorectal cancer (CRC), but resistance to αPD-1 therapy remains a major clinical challenge. The role and mechanism of deubiquitinating enzymes in regulating αPD-1 resistance in CRC remain poorly understood. In this study, we used clinical cohorts and the MC38 mouse CRC model to investigate USP13 expression in αPD-1-sensitive and αPD-1-resistant tumors. The function of USP13 was evaluated using the MC38 syngeneic tumor model and flow cytometry, and the molecular mechanism underlying the interaction between USP13 and SOCS1 was explored by ubiquitination assays, co-immunoprecipitation, and adenovirus-mediated USP13 overexpression. We found that USP13 was significantly downregulated in αPD-1-resistant MSI-H CRC patients and in resistant MC38 tumors, and that USP13 expression was significantly associated with prognosis specifically in MSI-H CRC patients. Functionally, USP13 knockout promoted αPD-1 resistance in MC38 tumors and reduced CD8 + T-cell infiltration. Mechanistically, loss of USP13 enhanced JAK-STAT pathway activation, while USP13 interacted with SOCS1, increased SOCS1 protein stability, and mediated K63-linked deubiquitination of SOCS1. Collectively, these findings demonstrate that USP13 stabilizes SOCS1 by removing K63-linked ubiquitination, thereby restraining excessive JAK-STAT activation and reversing resistance to αPD-1 therapy in MSI-H CRC. Targeting the USP13-SOCS1 axis may therefore represent a promising combination immunotherapeutic strategy for MSI-H CRC.

Medulloblastoma (MB) is the most common malignant pediatric brain tumor with poor prognosis, high recurrence, and severe treatment-related toxicities. One-third of MB are driven by aberrant activation of the Sonic hedgehog (SHH) signaling pathway. In current study, through analysis of clinical patient cohorts and animal model database, and utilizing genetically engineered primary and xenograft mouse MB models, we investigated the role of Sirtuin1 (Sirt1), a class III histone deacetylase (HDAC), in SHH signaling and MB. We found that Sirt1 was highly expressed in both human and mouse SHH-type MB, and its expression positively correlated with SHH pathway activity and tumor proliferation. Knockdown of Sirt1 in primary MB cells significantly suppressed SHH signaling and MB proliferation in vitro, further impaired neoplastic progression and extended survival in orthotopic transplantation MB model. Mechanistically, we discovered that Sirt1 modulates SHH signaling at downstream by interacting with and deacetylating full-length Gli3 (Gli3FL), thereby inhibiting its proteolytic processing into the repressor form (Gli3R), which attenuates the negative feedback regulation of SHH signaling, sustaining pathway activation and promoting tumor progression. Importantly, pharmacological inhibition of Sirt1 demonstrated promising therapeutic efficacy in both subcutaneous transplantation and primary MB models. Our findings identify Sirt1 as a potential therapeutic target for SHH-driven MB and other cancers.

In bacterial oncotherapy, tumor-targeting bacteria deliver cytotoxins that induce cancer-cell apoptosis, requiring exogenous cues to induce such cytotoxins. We mined the part of the Escherichia coli genome regulating immunotoxin (anticancer protein) to maximize tumor-specific activity. E. coli was introduced into a mouse tumor model, and RNA-seq analysis was performed. csrB, encoding small regulatory RNA, was highly upregulated in tumors. Genes controlled by csrB participate in acetate metabolism, enriched in the tumor microenvironment. qPCR of in vitro bacterial culture revealed that csrB expression depended on acetate levels. The csrB-promoter regulated acetate-controlled expression of β-galactosidase. For E. coli-mediated oncotherapy, we therefore selected the csrB promoter to regulate a recombinant form of immunotoxin, psp-TGFα-PE38, comprising TGFα, Pseudomonas exotoxin A, with a secretion tag (psp). Under csrB-promoter control, TP was notably expressed when acetate was present. Tumor-cell viability was dramatically reduced following treatment with the TP-containing bacterial-culture supernatant. TP was continuously present in the tumors of CT26-tumor-bearing mice administered TP-expressing E. coli. When exogenous stimuli were absent and TP was expressed by E. coli, tumor growth was substantially retarded, and the survival period increased. Tumor-colonizing bacteria thus offer promise in sensing tumor conditions and altering antitumor protein expression, potentially improving outcomes.