Asparagine drives immune evasion in bladder cancer via RIG-I stability and type I IFN signaling

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Abstract

Tumor cells often employ many ways to restrain type I interferon signaling to evade immune surveillance. However, whether cellular amino acid metabolism regulate this process remains unclear and its effects on antitumor immunity are relatively unexplored. Here, we find that asparagine inhibits IFN-I signaling and promotes immune escape in bladder cancer. Depletion of asparagine synthetase (ASNS) strongly limits in vivo tumor growth in a CD8+ T cell-dependent manner and boosts immunotherapy efficacy. Moreover, clinically approved ASNase synergizes with anti-PD-1 therapy in suppressing tumor growth. Mechanistically, asparagine can directly bind to RIG-I and facilitate CBL-mediated RIG-I degradation, thereby suppressing IFN signaling and antitumor immune responses. Clinically, tumors with higher ASNS expression show decreased responsiveness to ICIs therapy. Together, our findings uncover asparagine as a natural metabolite to modulate RIG-I-mediated IFN-I signaling, providing the basis for developing the combinatorial use of ASNase and anti-PD-1 for bladder cancer.

Authors

Wenjie Wei, Hongzhao Li, Shuo Tian, Chi Zhang, Junxiao Liu, Wen Tao, Tianwei Cai, Yuhao Dong, Chuang Wang, Dingyi Lu, Yakun Ai, Wanlin Zhang, Hanfeng Wang, Kan Liu, Yang Fan, Yu Gao, Qingbo Huang, Xin Ma, Baojun Wang, Xu Zhang, Yan Huang

Reduced EIF6 dosage attenuates TP53 activation in models of Shwachman-Diamond syndrome

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Abstract

Shwachman-Diamond syndrome (SDS) is characterized by neutropenia, exocrine pancreatic insufficiency, and bony abnormalities with an increased risk of myeloid neoplasia. Almost all cases of SDS result from biallelic mutations in SBDS. SBDS interacts with EFL1 to displace EIF6 from the 60S ribosomal subunit. Released EIF6 permits the assembly of ribosomal large and small subunits in the cytoplasm. Decreased EIF6 levels due to haploinsufficiency or missense mutations which lead to decreased protein expression may provide a somatic genetic rescue and anti-leukemic effects. We observed accumulation of EIF6 protein in sbds knockout (KO) zebrafish models, confirmed in patient-derived tissues, and correlated with changes in ribosome proteins and TP53 pathways. The mechanism of action for this adaptive response is unknown. To address this, we generated an eif6 zebrafish KO line which do not survive past 10 days post fertilization. We also created two mutants with low Eif6 expression, 5-25% of the wildtype levels, that can survive until adulthood. We bred them with sbds-null strains and analyzed their phenotype and biochemical properties. Low Eif6 levels reduced Tp53 pathway activation but did not rescue neutropenia in Sbds-deficient zebrafish. Further studies elucidating the interplay between SBDS, EIF6, TP53, and cellular stress responses offer promising insights into SDS pathogenesis, somatic genetic rescue, and therapeutic strategies.

Authors

Usua Oyarbide, Valentino Bezzerri, Morgan Staton, Christian Boni, Arish Shah, Marco Cipolli, Eliezer Calo, Seth J. Corey

Super-enhancer-driven EFNA1 fuels tumor progression in cervical cancer via the FOSL2-Src/AKT/STAT3 axis

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Abstract

Super-enhancers (SEs) are expansive cis-regulatory elements known for amplifying oncogene expression across various cancers. However, their role in cervical cancer (CC), a remarkable global malignancy affecting women, remains underexplored. Here we applied integrated epigenomic and transcriptomic profiling to delineate the distinct SE landscape in CC by analyzing paired tumor and normal tissues. Our study identifies a tumor-specific SE at the EFNA1 locus that drives EFNA1 expression in CC. Mechanically, the EFNA1 SE region contains consensus sequences for the transcription factor FOSL2, whose knockdown markedly suppressed luciferase activity and diminished H3K27ac enrichment within the SE region. Functional analyses further underlined EFNA1’s oncogenic role in CC, linking its overexpression to poor patient outcomes. EFNA1 knockdown strikingly reduced CC cell proliferation, migration, and tumor growth. Moreover, EFNA1 cis-interacted with its receptor EphA2, leading to decreased EphA2 tyrosine phosphorylation and subsequent activation of the Src/AKT/STAT3 forward signaling pathway. Inhibition of this pathway with specific inhibitors substantially attenuated the tumorigenic capacity of EFNA1-overexpressing CC cells in both in vitro and in vivo models. Collectively, our study unveils the critical role of SEs in promoting tumor progression through the FOSL2-EFNA1-EphA2-Src/AKT/STAT3 axis, providing new prognostic and therapeutic avenues for CC patients.

Authors

Shu-Qiang Liu, Xi-Xi Cheng, Shuai He, Tao Xia, Yi-Qi Li, Wan Peng, Ya-Qing Zhou, Zi-Hao Xu, Mi-Si He, Yang Liu, Pan-Pan Wei, Song-Hua Yuan, Chang Liu, Shu-Lan Sun, Dong-Ling Zou, Min Zheng, Chun-Yan Lan, Chun-Ling Luo, Jin-Xin Bei

Aberrant ERK signaling in astrocytes impairs learning and memory in RASopathy-associated BRAF mutant mouse models

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Abstract

RAS/MAPK pathway mutations often induce RASopathies with overlapping features, such as craniofacial dysmorphology, cardiovascular defects, dermatologic abnormalities, and intellectual disabilities. Although BRAF gene mutations are associated with cardio-facio-cutaneous (CFC) syndrome and Noonan syndrome, it remains unclear how these mutations impair cognition. Here, we investigated the underlying neural mechanisms using several mouse models harboring a gain-of-function BRAF mutation (K499E) discovered in RASopathy patients. We found expressing BRAF K499E (KE) in neural stem cells under the control of a Nestin-Cre promoter (Nestin;BRAFKE/+) induced hippocampal memory deficits, but expressing it in excitatory or inhibitory neurons did not. BRAF KE expression in neural stem cells led to aberrant reactive astrogliosis, increased astrocytic Ca2+ fluctuations, and reduced hippocampal long-term depression (LTD) in mice. Consistently, 3D human cortical spheroids expressing BRAF KE also showed reactive astrogliosis. Astrocyte-specific AAV-BRAF KE delivery induced memory deficits, reactive astrogliosis, and increased astrocytic Ca2+ fluctuations. Notably, reducing ERK activity in astrocytes rescued the memory deficits and altered astrocytic Ca2+ activity of Nestin;BRAFKE/+ mice. Furthermore, reducing astrocyte Ca2+ activity rescued the spatial memory impairments of BRAF KE-expressing mice. Our results demonstrate that ERK hyperactivity contributes to astrocyte dysfunction associated with Ca2+ dysregulation, leading to the memory deficits of BRAF-associated RASopathies.

Authors

Minkyung Kang, Jihye Choi, Jeongho Han, Toshiyuki Araki, Soo-Whee Kim, Hyun-Hee Ryu, Min-Gyun Kim, Seoyeon Kim, Hanbyul Jang, Sun Yong Kim, Kyoung-Doo Hwang, Soobin Kim, Myeongjong Yoo, Jaegeon Lee, Kitae Kim, Pojeong Park, Ja Eun Choi, Dae Hee Han, Yujin Kim, Jeongyeon Kim, Sunghoe Chang, Bong-Kiun Kaang, Jung Min Ko, Keun-Ah Cheon, Joon-Yong An, Sang Jeong Kim, Hyungju Park, Benjamin G. Neel, Chul Hoon Kim, Yong-Seok Lee

KRAS Mutants Confer Platinum Resistance by Regulating ALKBH5 Post-translational Modifications in Lung Cancer

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Abstract

Constitutively active mutations of KRAS are prevalent in non-small cell lung cancer (NSCLC). However, the relationship between these mutations and resistance to platinum-based chemotherapy and the underlying mechanisms remain elusive. In this study, we demonstrated that KRAS mutants confer resistance to platinum in NSCLC. Mechanistically, KRAS mutants mediate platinum resistance in NSCLC cells by activating ERK/JNK signaling, which inhibits ALKBH5 m6A demethylase activity by regulating post-translational modifications (PTMs) of ALKBH5. Consequently, the KRAS mutant leads to a global increase in m6A methylation of mRNAs, particularly DDB2 and XPC, which are essential for nucleotide excision repair. This methylation stabilized the mRNA of these two genes, thus enhancing NSCLC cells’ ability to repair platinum-induced DNA damage and avoid apoptosis, thereby contributing to drug resistance. Furthermore, blocking KRAS-mutant-induced m6A methylation, either by overexpressing a SUMOylation-deficient mutant of ALKBH5, or by inhibiting METTL3 pharmacologically, significantly sensitizes KRAS-mutant NSCLC cells to platinum drugs in vitro and in vivo. Collectively, our study uncovers a previously unrecognized mechanism that mediates KRAS mutant-induced chemoresistance in NSCLC cells by activating DNA repair through the modulation of the ERK/JNK/ALKBH5 PTMs-induced m6A modification in DNA damage repair-related genes.

Authors

Fang Yu, Shikan Zheng, Chunjie Yu, Sanhui Gao, Zuqi Shen, Rukiye Nar, Zhexin Liu, Shuang Huang, Lizi Wu, Tongjun Gu, Zhijian Qian

Metastatic Tumor Growth in Steatotic Liver is Promoted by HAS2-Mediated Fibrotic Tumor Microenvironment

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Abstract

Steatotic liver enhances liver metastasis of colorectal cancer, but this process is not fully understood. Steatotic liver induced by a high-fat diet (HFD) increases cancer-associated fibroblast (CAF) infiltration and collagen and hyaluronic acid (HA) production. We investigated the role of HA synthase 2 (HAS2) in the fibrotic tumor microenvironment in steatotic liver using Has2ΔHSC mice, in which Has2 is deleted from hepatic stellate cells. Has2ΔHSC mice had reduced steatotoic liver-associated metastatic tumor growth of MC38 colorectal cancer cells, collagen and HA deposition, and CAF and M2 macrophage infiltration. We found low-molecular-weight HA activates yes-associated protein (YAP) in cancer cells, which then releases connective tissue growth factor to further activate CAFs for HAS2 expression. Single-cell analyses revealed a link between CAF-derived HAS2 with M2 macrophages and colorectal cancer cells through CD44; these cells associated with exhausted CD8 T cells via programmed death-ligand 1 and programmed cell death protein 1. The HA synthesis inhibitors reduced steatotic liver-associated metastasis of colorectal cancer, YAP expression, CAF and M2 macrophage infiltration. In conclusion, steatotic liver modulates a fibrotic tumor microenvironment to enhance metastatic cancer activity through a bidirectional regulation between CAFs and metastatic tumors, enhancing the metastatic potential of colorectal cancer in the liver.

Authors

Yoon Mee Yang, Jieun Kim, Zhijun Wang, Jina Kim, So Yeon Kim, Gyu Jeong Cho, Jee Hyung Lee, Sun Myoung Kim, Takashi Tsuchiya, Michitaka Matsuda, Vijay Pandyarajan, Stephen J. Pandol, Michael S. Lewis, Alexandra Gangi, Paul W. Noble, Dianhua Jiang, Akil Merchant, Edwin M. Posadas, Neil A. Bhowmick, Shelly C. Lu, Sungyong You, Alexander M. Xu, Ekihiro Seki

PGLYRP2 drives hepatocyte-intrinsic innate immunity by trapping and clearing hepatitis B virus

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Abstract

Spontaneous clearance of hepatitis B virus (HBV) is frequent in adults (95%) but rare in infants (5%), emphasizing the critical role of age-related hepatic immunocompetence. However, the underlying mechanisms of hepatocyte-specific immunosurveillance and age-dependent HBV clearance remain unclear. Here, we identified PGLYRP2 as a hepatocyte-specific pattern recognition receptor with age-dependent expression, and demonstrated that phase separation of PGLYRP2 was a critical driver of spontaneous HBV clearance in hepatocytes. Mechanistically, PGLYRP2 recognized and potentially eliminated covalently closed circular DNA (cccDNA) via phase separation, coordinated by its intrinsically disordered region and HBV DNA-binding domain (PGLYRP2IDR/209-377) in the nucleus. Additionally, PGLYRP2 suppressed HBV capsid assembly by directly interacting with the viral capsid, mediated by its PGRP domain. This interaction promoted the nucleocytoplasmic translocation of PGLYRP2 and subsequent secretion of the PGLYRP2-HBV capsid complex, thereby bolstering the hepatic antiviral response. Pathogenic variants or deletions in PGLYRP2 impaired its ability to inhibit HBV replication, highlighting its essential role in hepatocyte-intrinsic immunity. These findings suggest that targeting the PGLYRP2-mediated host-virus interaction may offer a potential therapeutic strategy for the development of anti-HBV treatments, representing a promising avenue for achieving a functional cure for HBV infection.

Authors

Ying Li, Huihui Ma, Yongjian Zhang, Tinghui He, Binyang Li, Haoran Ren, Jia Feng, Jie Sheng, Kai Li, Yu Qian, Yunfeng Wang, Haoran Zhao, Jie He, Huicheng Li, Hongjin Wu, Yuanfei Yao, Ming Shi

Ablating VHL in Rod Photoreceptors Modulates RPE Glycolysis and Improves Preclinical Model of Retinitis Pigmentosa

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Abstract

Neuroretinal degenerations including retinitis pigmentosa (RP) comprise a heterogeneous collection of pathogenic mutations that ultimately result in blindness. Despite recent advances in precision medicine, therapies for rarer mutations are hindered by burdensome developmental costs. To this end, Von Hippel-Lindau (VHL) is an attractive therapeutic target to treat RP. By ablating VHL in rod photoreceptors and elevating hypoxia-inducible factor (HIF) levels, we demonstrate a path to therapeutically enhancing glycolysis independent of the underlying genetic variant that slows degeneration of both rod and cone photoreceptors in a preclinical model of retinitis pigmentosa. This rod-specific intervention also resulted in reciprocal, decreased glycolytic activity within the retinal pigment epithelium (RPE) cells despite no direct genetic modifications to the RPE. Suppressing glycolysis in the RPE provided notable, non-cell-autonomous therapeutic benefits to the photoreceptors, indicative of metabolically sensitive crosstalk between different cellular compartments of the retina. Surprisingly, targeting HIF2A in RPE cells did not impact RPE glycolysis, potentially implicating HIF1A as a major regulator in mouse RPE and providing a rationale for future therapeutic efforts aimed at modulating RPE metabolism.

Authors

Salvatore Marco Caruso, Xuan Cui, Brian M. Robbings, Noah Heaps, Aykut Demikrol, Bruna Lopes da Costa, Daniel T. Hass, Peter M.J. Quinn, Jianhai Du, James B. Hurley, Stephen H. Tsang

Integrative analysis reveals therapeutic potential of pyrvinium pamoate in Merkel cell carcinoma

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Abstract

Merkel Cell Carcinoma (MCC) is an aggressive neuroendocrine cutaneous malignancy arising from either ultraviolet-induced mutagenesis or Merkel cell polyomavirus (MCPyV) integration. Despite extensive research, our understanding of the molecular mechanisms driving the transition from normal cells to MCC remains limited. To address this knowledge gap, we assessed the impact of inducible MCPyV T antigens on normal human fibroblasts by performing RNA sequencing. Our data uncovered changes in expression and regulation of Wnt signaling pathway members. Building on this observation, we bioinformatically evaluated various Wnt pathway perturbagens for their ability to reverse the MCC gene expression signature and identified pyrvinium pamoate, an FDA-approved anthelminthic drug known for its anti-tumor activity in other cancers. Leveraging transcriptomic, network, and molecular analyses, we found that pyrvinium targets multiple MCC vulnerabilities. Pyrvinium not only reverses the neuroendocrine features of MCC by modulating canonical and non-canonical Wnt signaling but also inhibits cancer cell growth by activating p53-mediated apoptosis, disrupting mitochondrial function, and inducing endoplasmic reticulum stress. Finally, we demonstrated that pyrvinium reduces tumor growth in an MCC mouse xenograft model. These findings offer a new understanding of the role of Wnt signaling in MCC and highlight the utility of pyrvinium as a potential treatment for MCC.

Authors

Jiawen Yang, James T. Lim, Paul Victor Santiago Raj, Marcelo G. Corona, Chen Chen, Hunain Khawaja, Qiong Pan, Gillian D. Paine-Murrieta, Rick G. Schnellmann, Denise J. Roe, Prafulla C. Gokhale, James A. DeCaprio, Megha Padi

Endothelial-specific postnatal deletion of Nos3 preserves intraocular pressure homeostasis via macrophage recruitment and NOS2 upregulation

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Abstract

Polymorphisms in Nos3 increases risk for glaucoma, the leading cause of irreversible blindness worldwide. A key modifiable risk factor for glaucoma is intraocular pressure (IOP), which is regulated by nitric oxide (NO), a product of nitric oxide synthase-3 (Nos3) in Schlemm’s canal of the conventional outflow pathway. We studied the effects of a conditional, endothelial-specific postnatal deletion of Nos3 (Endo-SclCre-ERT;Nos3flox/flox) on tissues of the outflow pathway. We observed that Cre-ERT expression spontaneously and gradually increased with time in vascular endothelia including Schlemm’s canal, beginning at P10, with complete Nos3 deletion occurring around P90. Unlike the reduced outflow resistance in global Nos3 knockout mice, outflow resistance and IOP in Endo-SclCre-ERT;Nos3flox/flox mice were normal. Coinciding with Nos3 deletion, we observed recruitment of macrophages to, and induction of both ELAM-1 and NOS2 expression by endothelia in the distal portion of the outflow pathway, which increased vessel diameter. These adjustments reduced outflow resistance to maintain IOP in these Endo-SclCre-ERT;Nos3flox/flox mice. Selective inhibition of iNOS by 1400W resulted in narrowing of distal vessels and IOP elevation. Together, results emphasize the pliability of the outflow system, the importance of NO signaling in IOP control and implicates an important role for macrophages in IOP homeostasis.

Authors

Ruth A. Kelly, Megan S. Kuhn, Ester Reina-Torres, Revathi Balasubramanian, Kristin M. Perkumas, Guorong Li, Takamune Takahashi, Simon W.M. John, Michael H. Elliott, Darryl R. Overby, W. Daniel Stamer