The AAA+ ATPase VPS4 drives the ESCRT machinery in diverse intracellular membrane remodeling events, including endocytic receptor sorting, membrane repair, and autophagosome closure. Tumor cells often lose one VPS4 paral...The AAA+ ATPase VPS4 drives the ESCRT machinery in diverse intracellular membrane remodeling events, including endocytic receptor sorting, membrane repair, and autophagosome closure. Tumor cells often lose one VPS4 paralog (VPS4A or VPS4B), making them dependent on the remaining enzyme and creating a potential therapeutic vulnerability. Inhibiting VPS4 induces cancer cell-autonomous death and may also modulate the immune microenvironment, although the underlying mechanisms remain unclear. Here, we report that VPS4 inhibition triggered upregulation of cytokine and innate immune signaling, along with canonical NF-κB, stress response, and cell death pathways in murine rhabdomyosarcoma (RMS) cells. Pharmacological and genetic analyses identified the cGAS-STING-TBK1-IRF3 axis, activated by cytoplasmic mitochondrial DNA, as the primary driver of cytokine induction. In an orthotopic syngeneic RMS model, VPS4 inhibition suppressed tumor growth while fostering a more immunogenic microenvironment. Although STING was dispensable for VPS4 inhibition-induced RMS cell death, its loss reduced natural killer and dendritic cell infiltration and attenuated the overall anti-tumor effects of VPS4 inhibition. These findings establish a dual role for VPS4 inhibition in inducing tumor cell death and promoting anti-tumor immunity, highlighting the therapeutic potential of targeting VPS4 vulnerability in cancer.
Aberrantly enhanced DNA damage repair contributes to therapy resistance and poor prognosis in nasopharyngeal carcinoma (NPC), but its regulatory mechanisms remain unclear. Stress granules (SGs) mediate tumor stress adapt...Aberrantly enhanced DNA damage repair contributes to therapy resistance and poor prognosis in nasopharyngeal carcinoma (NPC), but its regulatory mechanisms remain unclear. Stress granules (SGs) mediate tumor stress adaptation, yet their role in NPC DNA damage repair is unknown. Here, we show that SGs are significantly enriched in NPC cells under stress, and the SG core protein G3BP1 is highly expressed in NPC tissues (n = 111), correlating with metastasis and poor survival. Mechanistically, under stress, N-acetyltransferase 10 (NAT10)-catalyzed N4-acetylcytosine (ac4C) modification targets mRNAs of DNA repair genes (ATF3, LIG1, RNF168) to SGs, protecting them from degradation. Upon stress relief, these mRNAs are released for translation, enhancing DNA damage repair. The G3BP1/NAT10/ATF3 axis is critical for NPC DNA repair and metastasis, as blocking this axis (via G3BP1 depletion, NAT10 inhibitor remodelin, or ATF3 knockout) inhibits tumor growth and metastasis in vitro and in vivo. This study uncovers a novel ac4C-dependent mechanism by which SGs regulate DNA damage repair in NPC, identifying the G3BP1/NAT10/ATF3 axis as a potential therapeutic target for improving NPC prognosis.
Dai Q, Lou L, Zhu X
… +17 more, Zhao H, Cai Z, Wei P, Zhong Y, Peng S, Hu X, Sun R, Tang X, Peng K, He Y, Gu F, Deng X, Zhou Y, Zhou J, Wang Y, Xue L, Guo X
The Hippo pathway is an evolutionarily conserved signaling cascade whose dysregulation is implicated in a wide range of diseases. While many RNA-binding proteins (RBPs) regulate this pathway through canonical functions s...The Hippo pathway is an evolutionarily conserved signaling cascade whose dysregulation is implicated in a wide range of diseases. While many RNA-binding proteins (RBPs) regulate this pathway through canonical functions such as modulating mRNA stability and translation, the potential for RBP-mediated regulation via non-canonical, RNA-binding-independent mechanisms remains poorly defined. Here, we report that the RBP TIAL1 exhibits oncogenic properties in hepatocellular carcinoma, promoting cancer cell proliferation, migration, and invasion. Mechanistically, TIAL1 directly interacts with the core Hippo component SAV1, disrupting the MST1-SAV1 interaction and thereby suppressing Hippo signaling and activating YAP. Notably, this regulatory function is independent of the RNA-binding activity of TIAL1. Furthermore, extracellular stimuli such as energy surplus and EGF significantly upregulate TIAL1 expression, linking microenvironmental cues to Hippo pathway dysregulation. Together, our results reveal a previously unrecognized, RNA-binding-independent mode of RBP-mediated regulation, in which TIAL1 serves as a molecular integrator that conveys extracellular signals to the Hippo pathway to drive hepatocellular carcinoma progression, providing potential avenues for therapeutic intervention.
Radioresistance remains the primary cause of radiotherapy failure in non-small cell lung cancer (NSCLC). This study investigated the regulatory role of HMOX1-mediated ferroptosis in NSCLC radiosensitivity. Radioresistant...Radioresistance remains the primary cause of radiotherapy failure in non-small cell lung cancer (NSCLC). This study investigated the regulatory role of HMOX1-mediated ferroptosis in NSCLC radiosensitivity. Radioresistant cell models (H1650R/H1975R) were established through fractionated irradiation of parental H1650/H1975 cells. Transcriptomic analysis by RNA sequencing revealed significant HMOX1 suppression in resistant cells. Functional validation demonstrated that HMOX1 overexpression enhanced radiation sensitivity via ferroptosis induction, whereas HMOX1 knockdown aggravated radioresistance. Mechanistic investigations identified USP7 as a key deubiquitinating enzyme that stabilizes KEAP1 through K48-linked polyubiquitin chain cleavage, thereby promoting NRF2 ubiquitination and suppressing HMOX1 transcription. Pharmacological inhibition using KI696 blocked KEAP1-NRF2 interaction, restoring HMOX1 expression. Notably, the USP7 inhibitor GNE-6640 destabilized KEAP1, upregulated NRF2/HMOX1 axis activity, and triggered ferroptosis in resistant cells. In vivo studies confirmed that GNE-6640 synergized with radiotherapy to suppress tumor growth and pulmonary metastasis in xenograft and NSG mouse models, as monitored by bioluminescence imaging. These findings establish the USP7-KEAP1-NRF2-HMOX1 axis as a critical determinant of radioresistance, demonstrating that targeted USP7 inhibition with GNE-6640 reactivates ferroptosis and restores radiosensitivity. This dual-mechanistic approach provides a novel therapeutic strategy to overcome treatment resistance in NSCLC.
PIWI proteins, a subfamily of the PAZ-PIWI domain (PPD) protein family, are traditionally regarded as germline factors that partner with PIWI-interacting RNAs (piRNAs) to silence transposons and regulate gene expression....PIWI proteins, a subfamily of the PAZ-PIWI domain (PPD) protein family, are traditionally regarded as germline factors that partner with PIWI-interacting RNAs (piRNAs) to silence transposons and regulate gene expression. However, growing evidence implicates PIWI proteins as oncogenic drivers in diverse somatic cancers, often acting through piRNA-independent mechanisms that remain incompletely understood. Here, we integrate transcriptomic, translatomic, and proteomic profiling of wild-type versus PIWIL1-knockout gastric cancer cells to uncover a non-canonical, translational role for PIWIL1, one of the four human PIWI proteins. We find that PIWIL1 selectively enhances the translation of 5'-terminal oligopyrimidine (TOP) mRNAs by activating mTOR complex 1 (mTORC1). Mechanistically, PIWIL1 interacts with the R2TP chaperone complex (RUVBL1-RUVBL2-RPAP3-PIH1D1) and promotes its association with TELO2, facilitating mTOR-RAPTOR assembly and mTORC1 activation. Functionally, PIWIL1 deficiency sensitizes gastric cancer cells to mTOR inhibition, and in clinical samples, PIWIL1 expression positively correlates with mTORC1 pathway activity. Together, these findings define a novel piRNA-independent mechanism through which PIWIL1 contributes to tumor progression, extend PIWI-mediated translational control from the germline to human cancers, and establish PIWIL1 as a potential therapeutic target for gastric cancer in synergy with mTOR inhibition.
Yu OM, Benitez JA, Plouffe SW
… +11 more, Ryback D, Klein A, Smith J, Greenbaum J, Delatte B, Rao A, Guan KL, Furnari FB, Chaim OM, Miyamoto S, Brown JH
Otani J, Nishio M, Tokita R
… +11 more, Hikasa H, Nishimori M, Dan S, Naguro I, Ichijo H, Miyanishi M, Sasaki T, Nishina H, Mak TW, Maehama T, Suzuki A
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 promisin...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...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 N-Threonylcarbamoyltransferase Domain Containing (YRDC) as a key mediator of temozolomide (TMZ) resistance in GBM. YRDC catalyzes the formation of N-threonylcarbamoyladenosine (tA) 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.
Efforts to block the mitogen-activated protein kinase (MAPK) pathway for colorectal cancer (CRC) therapy are challenged by frequent oncogenic mutations of its upstream genes, robust extracellular signal-regulated kinase...Efforts to block the mitogen-activated protein kinase (MAPK) pathway for colorectal cancer (CRC) therapy are challenged by frequent oncogenic mutations of its upstream genes, robust extracellular signal-regulated kinase (ERK) reactivation and difficulty in tumor-selective targeting without compromising the physiological processes of normal cells. Deeper insight into the precise mechanism of ERK regulation could help develop potential therapeutic strategies. Here, using integrated analyses of genomes, transcriptomes, and interactomes, we identified myotrophin (MTPN) as a crucial regulator of ERK. Further investigation using human CRC cells, xenograft models and tail vein metastasis models in nude mice and human CRC samples revealed that MTPN is involved in a noncanonical, endoplasmic-reticulum (ER)-associated mechanism that drives ERK activation in CRC. MTPN functions as a scaffold that mediates ERK binding to mitogen-activated protein kinase kinase (MEK) via a conserved ankyrin (ANK) domain, thereby promoting ERK-mediated malignancy phenotypes in CRC. MTPN is widely overexpressed in CRC tissues and is significantly correlated with hyperactivation of ERK and poor survival in patients with CRC. Targeting MTPN strikingly blocks ERK signaling without inducing ERK pathway reactivation, exhibiting a potent inhibitory effect on tumor growth and metastasis in a safe and stable manner. Our work reveals a crucial spatial regulatory mechanism that maintains ERK hyperactivation in CRC and highlights MTPN as a promising target for optimizing ERK-driven CRC therapy.
Glioblastoma (GBM) exhibits profound therapy resistance and inevitable recurrence, driven predominantly by glioblastoma stem cells (GSCs). S100A8 is positively associated with glioblastoma malignancy, but its expression...Glioblastoma (GBM) exhibits profound therapy resistance and inevitable recurrence, driven predominantly by glioblastoma stem cells (GSCs). S100A8 is positively associated with glioblastoma malignancy, but its expression and molecular mechanism in GSCs are poorly understood. Here, we demonstrated that S100A8 was highly expressed in GSCs and closely associated with shorter overall survival in GBM patients. The results showed that S100A8 maintained GSCs stemness by promoting cholesterol synthesis. Mechanistically, S100A8 bound to plasma membrane-localized RAGE, triggering ROS generation. Elevated ROS oxidized intracellular S100A8 at the Cys42 residue, thereby enhancing its affinity for mTORC1, subsequently inducing SREBP2-driven cholesterol synthesis. Furthermore, ROCK1-mediated phosphorylation of S100A8 at Thr3/Ser90, which stabilized S100A8 by impairing its binding to Fbxo10 and inhibiting the subsequent ubiquitination-mediated degradation. Our study reveals the S100A8-ROS-mTORC1 axis as a cholesterol metabolic vulnerability in GSCs, providing new insights into cholesterol metabolism and highlighting novel metabolism therapeutic strategies in GBM.
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 mechani...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 hedgeh...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.
Protein S-palmitoylation, a dynamic lipid modification, is essential for protein stability, trafficking, and signaling; dysregulated palmitoyltransferases drive cancer, yet systematic discovery of palmitoyltransferases r...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.
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 comm...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.
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 imm...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.
Dedifferentiated liposarcoma (DDLPS) is a rare and aggressive subtype of liposarcoma, driven by a core transcriptional regulatory circuitry (CRC) that sustains tumor proliferation. This malignancy poses considerable clin...Dedifferentiated liposarcoma (DDLPS) is a rare and aggressive subtype of liposarcoma, driven by a core transcriptional regulatory circuitry (CRC) that sustains tumor proliferation. This malignancy poses considerable clinical challenges, marked by high postoperative recurrence and metastatic potential, alongside a lack of effective targeted therapies. In this study, we establish that KPT-330 (Selinexor), a selective inhibitor of exportin 1 (XPO1), effectively compromises DDLPS cell viability by perturbing CRC homeostasis. Mechanistically, we demonstrate that KPT-330 attenuates the cellular translation machinery in a biphasic manner: initially, it disrupts translation initiation by suppressing eukaryotic translation initiation factor 4E phosphorylation and eukaryotic translation initiation factor 4 F complex assembly; subsequently, it impedes translation elongation by inhibiting the nuclear export of ribosomal large subunit proteins. Furthermore, we identify a synergistic antitumor effect between KPT-330 and translation inhibitors, including everolimus and homoharringtonine. Notably, the disruptive impact of KPT-330 on CRC homeostasis extends to other cancer cell lineages, underscoring its broad mechanistic relevance. Collectively, our findings elucidate a novel mechanism through which KPT-330 destabilizes CRC via translational dysregulation and highlight its potential therapeutic utility in combination regimens for DDLPS.