Oncology
Abstract
Tertiary lymphoid structures (TLS) in the tumor microenvironment (TME) are emerging solid-tumor indicators of prognosis and response to immunotherapy. Considering that tumorigenesis requires metabolic reprogramming and subsequent TME remodeling, the discovery of TLS metabolic regulators is expected to produce immunotherapeutic targets. To identify such metabolic regulators, we constructed a metabolism-focused sgRNA library and performed an in vivo CRISPR screening in an orthotopic lung tumor mouse model. Combined with The Cancer Genome Atlas database analysis of TLS-related metabolic hub genes, we found that the loss of Acat1 in tumor cells sensitized tumors to anti-PD1 treatment, accompanied by increased TLS in the TME. Mechanistic studies revealed that ACAT1 resulted in mitochondrial protein hypersuccinylation in lung tumor cells and subsequently enhanced mitochondrial oxidative metabolism, which impeded TLS formation. Elimination of ROS by NAC or Acat1 knockdown promoted B cell aggregation and TLS construction. Consistently, data from tissue microassays of 305 patients with lung cancer showed that TLS were more abundant in non–small cell lung cancer (NSCLC) tissues with lower ACAT1 expression. Intratumoral ACAT1 expression was associated with poor immunotherapy outcomes in patients with NSCLC. In conclusion, our results identified ACAT1 as a metabolic regulator of TLS and a promising immunotherapeutic target in NSCLC.
Authors
Mengxia Jiao, Yifan Guo, Hongyu Zhang, Haoyu Wen, Peng Chen, Zhiqiang Wang, Baichao Yu, Kameina Zhuma, Yuchen Zhang, Jingbo Qie, Yun Xing, Pengyuan Zhao, Zihe Pan, Luman Wang, Dan Zhang, Fei Li, Yijiu Ren, Chang Chen, Yiwei Chu, Jie Gu, Ronghua Liu
Abstract
Lysyl hydroxylase 2 (LH2) is highly expressed in multiple tumor types and accelerates disease progression by hydroxylating lysine residues on fibrillar collagen telopeptides to generate stable collagen cross links in tumor stroma. Here, we show that a galactosylhydroxylysyl glucosyltransferase (GGT) domain on LH2-modified type-VI collagen (Col6) to promote lung adenocarcinoma (LUAD) growth and metastasis. In tumors generated by LUAD cells lacking LH2 GGT domain activity, stroma was less stiff, and stable types of collagen cross links were reduced. Mass spectrometric analysis of total and glycosylated peptides in parental and GGT-inactive tumor samples identified Col6 chain α3 (Col6a3), a component of the Col6 heterotrimeric molecule, as a candidate LH2 substrate. In gain- and loss-of-function studies, high Col6a3 levels increased tumor growth and metastatic activity and enhanced the proliferative, migratory, and invasive activities of LUAD cells. LH2 coimmunoprecipitated with Col6a3, and LH2 glucosylated Col6 in an in vitro reaction. Glucosylation increased the integrin-binding and promigratory activities of Col6 in LUAD cells. Col6a3 K2049 was deglucosylated in GGT-inactive tumor samples, and mutagenesis of Col6a3 K2049 phenocopied Col6a3 deficiency or LH2 GGT domain inactivation in LUAD cells. Thus, LH2 glucosylates Col6 to drive LUAD progression. These findings show that the GGT domain of LH2 is protumorigenic, identify Col6 as a candidate effector, and provide a rationale to develop pharmacological strategies that target LH2’s GGT domain in cancer cells.
Authors
Shike Wang, Houfu Guo, Reo Fukushima, Masahiko Terajima, Min Liu, Guan-Yu Xiao, Lenka Koudelková, Chao Wu, Xin Liu, Jiang Yu, Emma Burris, Jun Xu, Alvise Schiavinato, William K. Russell, Mitsuo Yamauchi, Xiaochao Tan, Jonathan M. Kurie
Abstract
The anti-metastatic activity of NK cells is well established in several cancer types, but the mechanisms underlying NK cell metastasis infiltration and acquisition of anti-tumor characteristics remain unclear. Herein, we investigated the cellular and molecular factors required to facilitate the generation of an ILC1-like CD49a+NK cell population within the liver metastasis (LM) environment of colorectal cancer (CRC). We show that CD49a+NK cells had the highest cytotoxic capacity among metastasis-infiltrating NK cells in the MC38 mouse model. Furthermore, the chemokine receptor CXCR3 promoted CD49a+NK cell accumulation and persistence in metastasis where NK cells co-localize with macrophages in CXCL9 and CXCL10 rich areas. By mining a published scRNA-seq dataset of a cohort of treatment-naïve CRC patients, we confirmed the accumulation of CXCR3+NK cells in metastatic samples. Conditional deletion of Cxcr3 in NKp46+ cells and antibody-mediated depletion of metastasis-associated macrophages impaired CD49a+NK cell development, indicating that CXCR3 and macrophages contribute to efficient NK cell localization and polarization in LM. Conversely, CXCR3neg NK cells maintained a CD49a- phenotype in metastasis with reduced parenchymal infiltration and tumor killing capacity. Furthermore, CD49a+NK cell accumulation was impaired in an independent SL4-induced CRC metastasis model, which fails to accumulate CXCL9+ macrophages. Together, our results highlight a role for CXCR3/ligand axis in promoting macrophage-dependent NK cell accumulation and functional sustenance in CRC LM.
Authors
Eleonora Russo, Chiara D'Aquino, Chiara Di Censo, Mattia Laffranchi, Luana Tomaipitinca, Valerio Licursi, Stefano Garofalo, Johann Promeuschel, Giovanna Peruzzi, Francesca Sozio, Anna Kaffke, Cecilia Garlanda, Ulf Panzer, Cristina Limatola, Christian A. J. Vosshenrich, Silvano Sozzani, Giuseppe Sciumè, Angela Santoni, Giovanni Bernardini
Abstract
Tumor-associated macrophages (TAMs) are the most prominent immune cell population in the glioblastoma (GBM) tumor microenvironment (TME) and play critical roles in promoting tumor progression and immunosuppression. Here we identified that TAM-derived legumain (LGMN) exhibited a dual role in regulating the biology of TAMs and GBM cells. LGMN promoted macrophage infiltration in a cell-autonomous manner by activating the GSK3b-STAT3 pathway. Moreover, TAM-derived LGMN activated the integrin aV-AKT-P65 signaling to drive GBM cell proliferation and survival. Targeting LGMN-directed macrophage (inhibiting GSK3b and STAT3) and GBM cell (inhibiting integrin aV) mechanisms resulted in an anti-tumor effect in immunocompetent GBM mouse models that was further enhanced when combined with anti-PD1 therapy. Our study reveals a paracrine and autocrine mechanism of TAM-derived LGMN in promoting GBM progression and immunosuppression, providing effective therapeutic targets for improving immunotherapy in GBM.
Authors
Lizhi Pang, Songlin Guo, Yuyun Huang, Fatima Khan, Yang Liu, Fei Zhou, Justin D. Lathia, Peiwen Chen
Abstract
Allosteric inhibitors of the tyrosine phosphatase SHP2 hold therapeutic promise in cancers with overactive RAS/ERK signaling but “adaptive resistance” to SHP2 inhibitors may limit benefits. Here, we utilized tumor cells that proliferate similarly with or without endogenous SHP2 to explore means to overcome this growth-independence from SHP2. We found that SHP2 depletion profoundly alters output of vascular regulators, cytokines, chemokines, and other factors from SHP2 growth-resistant cancer cells. Tumors derived from inoculation of SHP2-depleted, but SHP2 growth-independent, mouse melanoma and colon carcinoma cell lines display a typically subverted architecture where proliferative tumor cells cluster in distinct “vascular islands” centered by remodeled vessels, each limited by surrounding hypoxic and dead tumor tissue, where inflammatory blood cells are limited. Although vascular islands generally reflect protected sanctuaries for tumor cells, we found that vascular island-resident, highly proliferative, SHP2-depleted tumor cells acquire an increased sensitivity to blocking MEK/ERK signaling resulting in reduced tumor growth. Our results show that response to targeted therapies in resistant tumor cells is controlled by tumor cell-induced vascular changes and tumor architectural reorganization providing a compelling approach to eliciting tumor response by exploiting tumor and endothelial-dependent biochemical changes.
Authors
Yuyi Wang, Hidetaka Ohnuki, Andy D. Tran, Dunrui Wang, Taekyu Ha, Jing-Xin Feng, Minji Sim, Raymond Barnhill, Claire Lugassy, Michael R. Sargen, Emanuel Salazar-Cavazos, Michael Kruhlak, Giovanna Tosato
Abstract
Mutations and deletions in TP53 are associated with adverse outcomes in patients with myeloid malignancies and developing improved therapies for TP53-mutant leukemias is of urgent need. Here we identify mutations in TET2 as the most common co-occurring mutation in TP53 mutant acute myeloid leukemia (AML) patients. In mice, combined hematopoietic-specific deletion of TET2 and TP53 resulted in enhanced self-renewal compared to deletion of either gene alone. Tp53/Tet2 double knockout mice developed serially transplantable AML. Both mice and AML patients with combined TET2/TP53 alterations upregulated innate immune signaling in malignant granulocyte-monocyte progenitors (GMPs), which had leukemia-initiating capacity. A20 governs the leukemic maintenance by triggering aberrant non-canonical NF-κB signaling. Mice with Tp53/Tet2 loss had expansion of monocytic myeloid-derived suppressor cells (MDSCs), which impaired T cell proliferation and activation. Moreover, mice and AML patients with combined TP53/TET2 alterations displayed increased expression of the TIGIT ligand, CD155, on malignant cells. TIGIT blocking antibodies augmented NK cell-mediated killing of Tp53/Tet2 double-mutant AML cells, reduced leukemic burden, and prolonged survival in Tp53/Tet2 double knockout mice. These findings uncover a leukemia-promoting link between TET2 and TP53 mutations and highlight therapeutic strategies to overcome the immunosuppressive bone marrow environment in this adverse subtype of AML.
Authors
Pu Zhang, Ethan C. Whipp, Sarah J. Skuli, Mehdi Gharghabi, Caner Saygin, Steven A. Sher, Martin Carroll, Xiangyu Pan, Eric D. Eisenmann, Tzung-Huei Lai, Bonnie K. Harrington, Wing Keung Chan, Youssef Youssef, Bingyi Chen, Alex Penson, Alexander M. Lewis, Cynthia R. Castro, Nina Fox, Ali Cihan, Jean-Benoit Le Luduec, Susan DeWolf, Tierney Kauffman, Alice S. Mims, Daniel Canfield, Hannah Phillips, Katie E. Williams, Jami Shaffer, Arletta Lozanski, Tzyy-Jye Doong, Gerard Lozanski, Charlene Mao, Christopher J. Walker, James S. Blachly, Anthony F. Daniyan, Lapo Alinari, Robert A. Baiocchi, Yiping Yang, Nicole R. Grieselhuber, Moray J. Campbell, Sharyn D. Baker, Bradley W. Blaser, Omar Abdel-Wahab, Rosa Lapalombella
Abstract
CD4+FOXP3+ regulatory T (Treg) cells maintain self-tolerance, suppress the immune response to cancer, and protect against tissue injury during acute inflammation. Treg cells require mitochondrial metabolism to function, but how Treg cells adapt their metabolic programs to optimize their function during an immune response occurring in a metabolically stressed microenvironment remains unclear. Here, we tested whether Treg cells require the energy homeostasis-maintaining enzyme AMPK to adapt to metabolically aberrant microenvironments caused by malignancy or lung injury, finding that AMPK is dispensable for Treg cell immune-homeostatic function but is necessary for full Treg cell function in B16 melanoma tumors and during influenza virus pneumonia. AMPK-deficient Treg cells had lower mitochondrial mass and exhibited an impaired ability to maximize aerobic respiration. Mechanistically, we found that AMPK regulates DNA methyltransferase 1 to promote transcriptional programs associated with mitochondrial function in the tumor microenvironment. During viral pneumonia, we found that AMPK sustains metabolic homeostasis and mitochondrial activity. Induction of DNA hypomethylation was sufficient to rescue mitochondrial mass in AMPK-deficient Treg cells, linking AMPK function to mitochondrial metabolism via DNA methylation. These results define AMPK as a determinant of Treg cell adaptation to metabolic stress and offer potential therapeutic targets in cancer and tissue injury.
Authors
Manuel A. Torres Acosta, Jonathan K. Gurkan, Qianli Liu, Nurbek Mambetsariev, Carla Reyes Flores, Kathryn A. Helmin, Anthony M. Joudi, Luisa Morales-Nebreda, Kathleen Cheng, Hiam Abdala-Valencia, Samuel E. Weinberg, Benjamin D. Singer
Abstract
Viral mimicry refers to the activation of innate antiviral immune responses due to the induction of endogenous retroelements (REs). Viral mimicry augments antitumor immune responses and sensitizes solid tumors to immunotherapy. Here, we found that targeting what we believe to be a novel, master epigenetic regulator, Zinc Finger Protein 638 (ZNF638), induces viral mimicry in glioblastoma (GBM) preclinical models and potentiates immune checkpoint inhibition (ICI). ZNF638 recruits the HUSH complex, which precipitates repressive H3K9me3 marks on endogenous REs. In GBM, ZNF638 is associated with marked locoregional immunosuppressive transcriptional signatures, reduced endogenous RE expression, and poor immune cell infiltration. Targeting ZNF638 decreased H3K9 trimethylation, increased REs, and activated intracellular dsRNA signaling cascades. Furthermore, ZNF638 knockdown upregulated antiviral immune programs and significantly increased PD-L1 immune checkpoint expression in diverse GBM models. Importantly, targeting ZNF638 sensitized mice to ICI in syngeneic murine orthotopic models through innate IFN signaling. This response was recapitulated in recurrent GBM (rGBM) samples with radiographic responses to checkpoint inhibition with widely increased expression of dsRNA, PD-L1, and perivascular CD8 cell infiltration, suggesting that dsRNA signaling may mediate response to immunotherapy. Finally, low ZNF638 expression was a biomarker of clinical response to ICI and improved survival in patients with rGBM and patients with melanoma. Our findings suggest that ZNF638 could serve as a target to potentiate immunotherapy in gliomas.
Authors
Deepa Seetharam, Jay Chandar, Christian K. Ramsoomair, Jelisah F. Desgraves, Alexandra Alvarado Medina, Anna Jane Hudson, Ava Amidei, Jesus R. Castro, Vaidya Govindarajan, Sarah Wang, Yong Zhang, Adam M. Sonabend, Mynor J. Mendez Valdez, Dragan Maric, Vasundara Govindarajan, Sarah R. Rivas, Victor M. Lu, Ritika Tiwari, Nima Sharifi, Emmanuel Thomas, Marcus Alexander, Catherine DeMarino, Kory Johnson, Macarena I. De La Fuente, Ruham Alshiekh Nasany, Teresa Maria Rosaria Noviello, Michael E. Ivan, Ricardo J. Komotar, Antonio Iavarone, Avindra Nath, John Heiss, Michele Ceccarelli, Katherine B. Chiappinelli, Maria E. Figueroa, Defne Bayik, Ashish H. Shah
Abstract
Protein arginine methyl transferases (PRMTs) are generally upregulated in cancers. However, the mechanisms leading to this upregulation and its biological consequences are poorly understood. Here, we identify PRMT5, the main symmetric arginine methyltransferase, as a critical driver of chemoresistance in high-grade serous ovarian cancer (HGSOC). PRMT5 levels and its enzymatic activity are induced in a platinum-resistant (Pt-resistant) state at the protein level. To reveal potential regulators of high PRMT5 protein levels, we optimized intracellular immunostaining conditions and performed unbiased CRISPR screening. We identified Kelch-like ECH-associated protein 1 (KEAP1) as a top-scoring negative regulator of PRMT5. Our mechanistic studies show that KEAP1 directly interacted with PRMT5, leading to its ubiquitin-dependent degradation under normal physiological conditions. At the genomic level, ChIP studies showed that elevated PRMT5 directly interacted with the promoters of stress response genes and positively regulated their transcription. Combined PRMT5 inhibition with Pt resulted in synergistic cellular cytotoxicity in vitro and reduced tumor growth in vivo in Pt-resistant patient-derived xenograft tumors. Overall, the findings from this study identify PRMT5 as a critical therapeutic target in Pt-resistant HGSOC cells and reveal the molecular mechanisms that lead to high PRMT5 levels in Pt-treated and chemo-resistant tumors.
Authors
Harun Ozturk, Fidan Seker-Polat, Neda Abbaszadeh, Yasemin Kingham, Sandra Orsulic, Mazhar Adli
Abstract
Despite advances in the development of direct KRAS inhibitors, KRAS-mutant cancers continue to exhibit resistance to the currently available therapies. Here, we identified REGγ as a mutant KRAS–associated factor that enhanced REGγ transcription through the KRAS intermediate NRF2, suggesting that the REGγ-proteasome is a potential target for pan-KRAS inhibitor development. We elucidated a mechanism involving the KRAS/NRF2/REGγ regulatory axis, which links activated KRAS to the ATP- and ubiquitin-independent proteasome. We subsequently developed RLY01, a REGγ-proteasome inhibitor that effectively suppressed tumor growth in KRAS-mutant cancer models and lung cancer organoids. Notably, the combination of RLY01 and the KRASG12C inhibitor AMG510 exhibited enhanced antitumor efficacy in KRASG12C cancer cells. Collectively, our data support the hypothesis that KRAS mutations enhance the capacity of the REGγ-proteasome by increasing REGγ expression, highlighting the potential of ubiquitin-independent proteasome inhibition as a therapeutic approach for pan-KRAS–mutant cancers.
Authors
Shihui Shen, Qiansen Zhang, Yuhan Wang, Hui Chen, Shuangming Gong, Yun Liu, Conghao Gai, Hansen Chen, Enhao Zhu, Bo Yang, Lin Liu, Siyuan Cao, Mengting Zhao, Wenjie Ren, Mengjuan Li, Zhuoya Peng, Lu Zhang, Shaoying Zhang, Juwen Shen, Bianhong Zhang, Patrick K.H. Lee, Kun Li, Lei Li, Huaiyu Yang
Copyright © 2026 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)