Oncology
Abstract
Immune checkpoint blockade (ICB), including PD-1/PD-L1 inhibitors, has transformed cancer therapy but benefits only a subset of patients. Understanding how PD-L1 is regulated and identifying strategies to overcome resistance remain critical. Here, we identify SIRT2 as a key positive regulator of PD-L1 across multiple human cancers. Unexpectedly, SIRT2 does not act at the transcriptional level but stabilizes PD-L1 protein by preventing ubiquitin-mediated degradation. Mechanistically, SIRT2 maintains the protein stability of USP22, a PD-L1 deubiquitinase. Loss of SIRT2 reduces USP22 levels, whereas ectopic USP22 fully rescues PD-L1 expression and reverses the enhanced antitumor immunity induced by SIRT2 inhibition. We further show that SIRT2 directly deacetylates USP22 at lysines 382 and 505 within its catalytic domain, promoting USP22 deubiquitinase activity and protecting both itself and its substrates from degradation. Our findings reveal a molecular mechanism by which an acetylation–deacetylation switch dynamically regulates deubiquitinase catalytic activity. Therapeutically, SIRT2 inhibition synergizes with PD-1/PD-L1 blockade and USP22 inhibition to enhance antitumor immunity. Consistently, protein but not mRNA levels of SIRT2, USP22, and PD- L1 positively correlate in human bladder cancer and melanoma. Together, these findings define a SIRT2–USP22–PD-L1 axis driving tumor immune evasion and highlight SIRT2 as a promising target to improve ICB efficacy.
Authors
Na Li, Qiong Gao, Huijun Jia, Guoqing Xue, Yuanzhang Zhou, Shengnan Wang, Suxian Ma, Bingjin Hu, Zhuoyue Zhao, Chen Su, Yinghong Liu, Wenxuan Xi, Zhonghao Li, Donna D. Zhang, Peng Chu, Zhaolin Sun, Deyu Fang
Abstract
Glioblastoma, IDH-wildtype (GBM, WHO grade 4) is the most common malignant glioma in adults and is characterized by a hypoxic and immunosuppressive tumor microenvironment (TME). Bone marrow-derived tumor-associated macrophages (TAMs) dominate the immune landscape in GBM and are recruited to the peri-necrotic niche following the onset of necrosis. CLEC5A has the strongest association with poor clinical outcome among immune-related genes in GBM, and is preferentially expressed in hypoxic, peri-necrotic TAMs. CLEC5A overexpression promotes TAM polarization toward an immunosuppressive phenotype, and secretion of immunoregulatory cytokines. Using an RCAS/tv-a GBM model with bone marrow transplantation from Clec5a-/- donor mice, we demonstrated that CLEC5A loss prolongs survival, delays tumor progression, and attenuates TME immunosuppression. Mechanistically, podoplanin (PDPN) expressed on glioma cells directly engages CLEC5A and triggers downstream Syk-JAK-STAT3 signaling in TAMs. Pharmacologic Syk inhibition suppresses glioma growth, diminishes TAM infiltration and polarization, reverses the immunosuppressive TME, and prolongs survival in vivo. Collectively, our findings indicate that the PDPN-CLEC5A-Syk-STAT3 axis orchestrates TAM polarization and TME immunosuppression in the peri-necrotic niche of GBM, highlighting CLEC5A/Syk as a promising therapeutic target for reversing the immunosuppressive TME and improving outcomes.
Authors
Jiabo Li, Xuya Wang, Luqing Tong, Bo Feng, Ling-kai Shih, Steven M. Markwell, Hannah Nuszen, Tomasz Gruchala, Nicholas G. Lam, Petros Basakis, Erika Ruiz-Yamamoto, Deyu Fang, Roger Stupp, Xuejun Yang, Daniel J. Brat
Abstract
Metabolic signals critically shape innate immune responses. Through pharmacological screening of metabolic pathways, we identified aspartate metabolism as a key regulator of cyclic GMP-AMP synthase (cGAS)–stimulator of interferon genes (STING) signaling. Genetically or aminooxyacetic acid–mediated (AOA-mediated) pharmacologically reducing aspartate levels markedly potentiated the cGAS-STING pathway, leading to stronger upregulation of type I interferons and interferon-stimulated genes. Mechanistically, disruption of de novo pyrimidine synthesis, a major downstream pathway of aspartate, induced mtDNA replication stress and increased mtDNA double-strand breaks, promoting mtDNA release into the cytosol. Cytosolic mtDNA synergized with cGAS-STING agonists to upregulate Z-DNA binding protein 1 (ZBP1), which recruits RIPK1/3 to sustain IRF3 phosphorylation, forming a positive feedback loop that amplifies innate immune signaling. In immunocompetent mouse models, AOA enhanced the antitumor efficacy of STING agonists, chemotherapy, or radiotherapy, whereas aspartate supplementation abrogated these effects. Consistently, aspartate levels negatively correlated with antitumor immunity in colorectal cancer patient samples. Together, our study identifies aspartate–pyrimidine metabolism as a critical metabolic checkpoint that licenses STING signaling by enabling mtDNA stress to cooperate with agonist stimulation, driving type I interferon–dependent ZBP1 induction and feed-forward amplification of STING signaling, thus offering a promising strategy to enhance antitumor immunity.
Authors
Yuheng Liao, Hanze Wang, Hengxin Liu, Xi Chen, Renqiang Sun, Xie Li, Zhen Yang, Chenying Liu, Wei Wu, Ziqian He, Yuzheng Zhao, Ying Mao, Dan Ye, Hui Yang
Abstract
Cancers reprogram their metabolism to provide anabolic needs without driving excessive oxidative stress. Attention has focused on glucose metabolism, yet amino acid synthesis and degradation also promote tumor cell states and growth. Here, we assessed amino acids that maintain cancer stem cells in glioblastoma and found increased proline levels relative to differentiated tumor progeny through increased proline synthesis. Cancer stem cells preferentially expressed the signaling molecule FAM3C induced by the stem cell transcription factor SOX2 to drive expression of proline synthesis enzymes. FAM3C classically mediated cellular responses as a secreted protein but gained intracellular functions in cancer stem cells through binding the histone reader spindlin 1 (SPIN1), thereby preventing its lysosomal degradation, assisting its nuclear localization, and promoting epigenetic regulation of proline synthesis. Proline synthesis depleted ROS, and genetic targeting of FAM3C attenuated ROS scavenging, whereas SPIN1 OE restored ROS levels. Molecular docking identified tucatinib as a brain-penetrant pharmacologic disruptor of FAM3C-SPIN1 interactions, promoting SPIN1 degradation and reducing intracellular proline levels. Thus, cancer stem cells induced a favorable metabolic state through proline synthesis and ROS depletion, revealing potential therapeutic dependencies.
Authors
Weichi Wu, Po Zhang, Donghai Wang, Xujia Wu, Qiulian Wu, Daqi Li, Tengfei Huang, Rui Wang, Huan Li, Hailong Mi, Suchet Taori, Fanen Yuan, Tingting Duan, Zhiye Chen, Huairui Yuan, Jeremy N. Rich
Abstract
Cancers reflect aberrant growth and differentiation of normal cell populations. Biological understanding of small intestine neuroendocrine tumors (SI-NETs) is hampered because their closest normal counterparts, enteroendocrine cells (EECs), constitute tiny fractions of intestinal epithelium. Recent characterization of adult human EEC ontogeny from intestinal stem cells can help overcome that limitation. Transient expression of transcription factor gene ASCL1 normally ensures proper timing and fidelity of well-differentiated EECs, which express NEUROD1. Here we report that SI-NETs resembled mature enterochromaffin cells; however, individual tumor cells co-expressed stem/progenitor genes, harboring each differentiation state along the EEC trajectory except ASCL1+ precursors. We found that enhancers normally active, and others inactive, during EEC differentiation underlie aberrant SI-NET gene activity. SI-NETs uniformly expressed NEUROD1 but lacked ASCL1, owing to inaccessible chromatin and repressive H3K27me3 marking at the ASCL1 locus. Multiple cyclin-dependent kinase inhibitor (CDKi) genes were similarly silenced, other than CDKN1B, the only gene recurrently mutated in SI-NETs. Deletion of CDKN1B altered cell cycle kinetics during human EEC differentiation, and deletions of ASCL1 or CDKN1B activated certain genes that are expressed in SI-NETs but not in the normal EEC trajectory. We propose that a limited CDKi repertoire and absence of ASCL1-dependent constraints on EEC maturation together explain unique SI-NET characteristics.
Authors
Pratik N.P. Singh, Elsa Hadj Bachir, James R. Howe, Andrew M. Bellizzi, Paloma Cejas, Shariq Madha-Krause, Charles B. Epstein, Jennifer Chan, Bradley E. Bernstein, Matthew H. Kulke, Qiao Zhou, Ramesh A. Shivdasani
Abstract
BACKGROUND. Minimally invasive biomarkers predicting immunotherapy response in head and neck squamous cell carcinoma (HNSCC) remain an unmet clinical need. METHODS. Using patients from a prospective, multi-institutional phase II trial, we performed whole-genome sequencing of 185 longitudinal plasma cell-free DNA (cfDNA) samples from 68 patients with locally advanced, surgically resectable HNSCC who received neoadjuvant and adjuvant pembrolizumab. We developed the regional motif diversity score (rMDS), a fragmentomic metric that quantifies the entropy of cfDNA 5′-end motifs across genomic regions. RESULTS. Unsupervised analysis showed rMDS robustly distinguished responders from non-responders, outperforming established fragmentomic metrics and copy number alterations while remaining independent of technical confounders. Longitudinal rMDS changes localized to regions enriched for immune-, lectin-, and keratinization-related genes — hallmarks of squamous cell carcinoma — reflecting tumor–peripheral immunity interplay during treatment. The most dynamic regions clustered at telomere-proximal loci, suggesting a link between telomere biology and cfDNA fragmentation. An rMDS-based machine learning classifier achieved AUC 0.89–0.99 across validation settings, with the highest accuracy post-treatment, outperforming PD-L1 expression and tumor fraction in matched samples. Predicted responders showed improved disease-free survival (log-rank P = 0.035; HR 2.67, 95% CI 1.03–6.92). CONCLUSION. rMDS represents a biologically meaningful, clinically actionable biomarker for immunotherapy response in HNSCC, supporting integration into future risk assessment frameworks. TRIAL REGISTRATION. ClinicalTrials.gov NCT02641093. FUNDING. NHGRI R56HG012360 and startup funds from Cincinnati Children’s Hospital Medical Center, Northwestern University, and Robert H. Lurie Comprehensive Cancer Center (Y.L.); Science Olympiad Alumni Research Grant, Science Olympiad USA Foundation (R.B.); Merck Sharp & Dohme Corp. (T.W.D.).
Authors
Ravi Bandaru, Hailu Fu, Haizi Zheng, Jocelyn Liang, Li Wang, Shuchi Gulati, Benjamin H. Hinrichs, Mingxiang Teng, Bin Zhang, Masha Kocherginsky, De-Chen Lin, David A. Hildeman, Francis P. Worden, Matthew O. Old, Neal E. Dunlap, John M. Kaczmar, Maura L. Gillison, Dalia El-Gamal, Trisha Wise Draper, Yaping Liu
Abstract
Cachexia is a metabolic wasting syndrome affecting many patients with cancer, with poor survival outcomes. Disturbed lipid metabolism is a hallmark of cachexia, and our previous work has identified increased levels of circulating ceramides, which are bioactive lipids with adverse effects in metabolic diseases, as biomarkers for cachexia in mouse models and patients. Here, we investigated the role of ceramides on cachexia development using the well-established C26 colon carcinoma model. We demonstrated that elevated ceramides in cachexia arose from increased liver synthesis. We showed that ceramides directly contributed to impaired mitochondrial function and energy homeostasis in cachexia target tissues. Targeting ceramide synthesis using miRNA interference, or myriocin, an approved compound targeting the key synthesis enzyme serine palmitoyltransferase (SPT), improved markers of muscle atrophy in cachectic male mice. Importantly, we demonstrated that key enzymes involved in ceramide production were also elevated in livers, but not in other organs, of patients with cancer cachexia, correlating with disease severity. Our data place ceramides as contributors to metabolic dysfunction in cachexia and highlight the suitability of the ceramide synthesis pathway for therapeutic targeting.
Authors
Pauline Morigny, Honglei Ji, Laura Cussonneau, Sabrina Zorzato, Yun Kwon, Fabien Riols, Doris Kaltenecker, Alisa Maier, Vignesh Karthikaisamy, Samantha Corrà, Tanja Krauss, Claudine Seeliger, Syed Qaaifah Gillani, Joël J. Tissink, Sandra Lacas-Gervais, Tuna Felix Samanci, Adriano Maida, Raul Terron-Exposito, Angela Trinca, Christine von Toerne, Leonardo Nogara, Melina Claussnitzer, Olga Prokopchuk, Jeannine Bachmann, Mauricio Berriel Diaz, Laure B. Bindels, Ondrej Kuda, Hans Hauner, Mark Haid, Stephan Herzig, Carlo Fiore Viscomi, Jerome Gilleron, Anja Zeigerer, Bert Blaauw, Maria Rohm
Abstract
BACKGROUND The relationship between molecular subgroups in clear-cell renal cell carcinoma (ccRCC) and metastatic tropism is poorly understood.METHODS We analyzed over 5,000 metastatic sites from 305 treatment-naive ccRCC patients in the IMmotion150 phase II clinical trial, where patients were randomized to atezolizumab, atezolizumab/bevacizumab, or sunitinib.RESULTS Angiogenic tumors (clusters 1 and 2) had a higher rate of pancreatic (21% vs. 6.9%; P = 0.002) and lower absolute number of lymph node (2.5 vs. 4.2; P = 0.006) metastases. In contrast, proliferative tumors (clusters 4 and 5) exhibited a higher absolute number of lymph node metastases (5.5 vs. 3.5; P = 0.019). Patients with pancreatic metastases receiving sunitinib had higher odds of overall response (OR, 7.13; 95% CI, 1.81–28.07; P = 0.0049) and longer progression-free survival than those without pancreatic metastases (P = 0.02).CONCLUSION ccRCC metastatic tropism relates to molecular clusters that predict response to therapy for tumors that metastasize to the pancreas.TRIAL REGISTRATION ClinicalTrials.gov NCT01984242FUNDING NIH grants R01CA154475 and P50CA196516.
Authors
Gaelle Haddad, Junyu Guo, Yin Xi, Emin Albayrak, Mahrukh Huseni, Habib Hamidi, Romain Banchereau, Edward Kadel, Sarita Dubey, Corey Carter, Payal Kapur, James Brugarolas, Ivan Pedrosa
Abstract
While radiation is an effective oncologic therapy, killing cancer by inducing DNA double-strand breaks (DSBs), it lacks specificity for neoplastic cells. We have previously adapted the CRISPR/Cas9 gene-editing technology as a cancer-specific treatment modality targeting somatic mutations in pancreatic cancer (PC). However, its tumoricidal potential remains unclear, especially in comparison with therapeutic doses of radiation. Here, we demonstrate that CRISPR/Cas9-induced DSBs are more cytotoxic in PCs than a comparable number of radiation-induced DSBs. We observed more than 90% tumor growth inhibition by targeting 9 sites with cancer-specific sgRNAs. Through both bioinformatics and cytogenetics analyses, we found that CRISPR/Cas9-induced DSBs triggered ongoing chromosomal rearrangements, with 87% of structural variants not directly produced from the initial CRISPR/Cas9-induced DSBs, and chromosomal instability peaking before cell death. By comparing the cytotoxicity of CRISPR/Cas9- and radiation-induced DSBs, we demonstrated that the number of DSBs required to achieve equitoxic effects was approximately 3 times higher for radiation than CRISPR/Cas9. Finally, we showed that PC cells that had survived CRISPR/Cas9 targeting retained susceptibility to subsequent CRISPR/Cas9-induced DSBs at different genomic sites with more than 87% growth inhibition. Together, our data support the therapeutic potential of CRISPR/Cas9 as an anticancer strategy.
Authors
Selina Shiqing K. Teh, Akhil Kotwal, Alexis Bennett, Eitan Halper-Stromberg, Laura Morsberger, Saum Zamani, Yanan Shi, Alyza Skaist, Qingfeng Zhu, Kirsten Bowland, Hong Liang, Ralph H. Hruban, Chien-Fu Hung, Robert A. Anders, Nicholas J. Roberts, Robert B. Scharpf, Michael Goldstein, Ying S. Zou, James R. Eshleman
Abstract
Bone metastasis remains a major cause of morbidity in estrogen receptor–positive breast cancer, with RANKL inhibitor resistance emerging as a critical clinical challenge. Nearly 40% of patients develop progressive skeletal lesions despite denosumab therapy, highlighting an urgent need to identify resistance mechanisms and alternative therapeutic strategies. We identified a RANKL-independent osteoclast activation pathway mediated by the CRKL/circCCDC50/NFATc1 axis. Mechanistically, CRKL promoted EIF4A3-dependent circCCDC50 biogenesis, which was packaged into large oncosomes and transferred to osteoclast precursors. Nuclear circCCDC50 recruited CARM1 to epigenetically activate NFATc1 transcription, establishing a self-reinforcing loop that sustained osteolysis despite RANKL blockade. Pharmacological inhibition of CARM1 (TP-064) effectively suppressed osteoclastogenesis and bone metastasis in denosumab-resistant models. These findings revealed a targetable resistance mechanism and provided a clinically actionable strategy to overcome microenvironment-driven metastasis through dual targeting of tumor and bone niches.
Authors
Qun Lin, Jinpeng Luo, Zhuxi Duan, Jieer Luo, Wei Zhang, Yuan Xia, Yinduo Zeng, Xiaolin Fang, Jiahui Liang, Jiayi Chen, Qianchong Lin, Yilin Quan, Ruiyu Hu, Hongcai Liu, Qiang Liu, Jun Li, Chang Gong
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ISSN: 0021-9738 (print), 1558-8238 (online)