Patient Samples Research Articles

Current smoking is related to severe damage in systemic lupus erythematosus patients

Objective To assess the relationship between smoking exposure and organ damage accrual measured by Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index for Systemic Lupus Erythematosus score (SLICC-SDI) in consecutive patients with systemic lupus erythematosus (SLE) from Argentina. Methods 623 consecutive SLE patients (fulfilling ≥4, 1997 ACR criteria) were included in this cross-sectional study. Sociodemographic and disease related variables including SLICC-SDI score and smoking status were collected. Patients currently smoking were considered “smokers”, and “non-smokers” those who never smoked and former smokers. SLICC-SDI was divided into two categories: <3 and ≥3 was defined as severe damage. Results Six hundred and 23 patients were included in the analysis, 89% women. Eighty-four per cent were non-smokers and 16 % were current smokers 83 percent of patients had SLICC-SDI <3 and 17 % had SLICC-SDI ≥3. Twenty one percent of patients with SLICC-SDI ≥3 and 15% with <3 SLICC-SDI were current smokers ( p 0.081). In the multiple regression analysis, current smoking (OR 1.82, CI 95% 1.01-3.31, p 0.046), older age (OR 1.04, CI 95% 1.00-1.05, p 0.034), disease duration (OR 1.03, CI 95% 1.00-1.07, p 0.021) and cyclophosphamide exposure (OR 2.97, CI 95% 1.49-5.88, p 0.002) were related to SLICC-SDI ≥3. Conclusion In our sample of patients, current smoking, older age, disease duration and cyclophosphamide were related to severe damage (SLICC-SDI ≥3).

Methyl-Beta-Cyclodextrin Restores Aberrant Bone Morphogenetic Protein 2-Signaling in Bone Marrow Stromal Cells Obtained from Aged C57BL/6 Mice

During aging, disruptions in various signaling pathways become more common. Some older patients will exhibit irregular bone morphogenetic protein (BMP) signaling, which can lead to osteoporosis (OP)—a debilitating bone disease resulting from an imbalance between osteoblasts and osteoclasts. In 2002, the Food and Drug Administration (FDA) approved recombinant human BMP-2 (rhBMP-2) for use in spinal fusion surgeries as it is required for bone formation. However, complications with rhBMP-2 arose and primary osteoblasts from OP patients often fail to respond to BMP-2. Although patient samples are available for study, previous medical histories can impact results. Consequently, the C57BL/6 mouse line serves as a valuable model for studying OP and aging. We find that BMP receptor type Ia (BMPRIa) is upregulated in the bone marrow stromal cells (BMSCs) of 15-month-old mice, consistent with prior data. Furthermore, conjugating BMP-2 with Quantum Dots (QDot®s) allows effective binding to BMPRIa, creating a fluorescent tag for BMP-2. Furthermore, after treating BMSCs with methyl-β-cyclodextrin (MβCD), a disruptor of cellular endocytosis, BMP signaling is restored in 15-month-old mice, as shown by von Kossa assays. MβCD has the potential to restore BMPRIa function, and the BMP signaling pathway offers a promising avenue for future OP therapies.

Abstract A013: Microenvironment driven dynamic deposition of histone H3.3 controls entry and exit from dormancy in disseminated cancer cells

Abstract Breast cancer metastases can go undetected for long periods of time, are highly resistant to therapy, and are the cause for more than 90% of breast cancer mortality. Dormancy is a critical step in the metastatic cascade, whereby disseminated cancer cells (DCCs) enter a non-proliferative state at distal sites until they reactivate and give rise to overt metastasis, often years after disease remission. As such, dormancy represents a major clinical obstacle in breast cancer patient care. Chromatin remodeling serves as a foundation for the cellular reprogramming required to drive cell fate transitions. However, little is known about the nature of this remodeling in dormancy. Here, we hypothesize that differential deposition of histone H3.3 determines whether DCCs enter and remain dormant in secondary organs or proliferate and form overt metastases. We used a combination of H3.3 deposition sensors and genetic tools to manipulate H3.3 and HIRA in vitro and in vivo to track H3.3 deposition through the metastatic cascade and evaluate its importance for dormancy. To evaluate relevance to patient disease we developed a dormancy score to implement from publicly available RNA seq. To define mechanism of regulation, we used a combination of whole genome sequencing (ChIP-seq, ATAC-seq and RNA-seq) followed by in-depth analysis and functional validation. Our data demonstrates that H3.3 incorporation at secondary sites is heterogenous, revealing a subset of DCCs with low H3.3 in chromatin. Blocking H3.3 deposition onto chromatin leads to a reversible arrest in G0/G1 which tracks with the activation of canonical dormancy signaling. Mechanistically, our data supports a model where blocking H3.3 incorporation into chromatin directly represses the expression of SKP2, the main regulator of progression through the restriction point of cell cycle via regulation of p27 degradation. SKP2 suppression in turn leads to the accumulation of p27 thereby causing cell cycle arrest in G0/G1 and dormancy establishment. We traced this H3.3-mediated regulation of dormancy through the dynamic regulation of H3.3 histone chaperone, HIRA, whose levels inversely correlate with dormancy in experimental models as well as in patient samples. We found that HIRA levels respond to the metastatic microenvironment where fibrotic conditions induce HIRA expression and trigger metastatic outgrowth in an H3.3-dependent manner. Together, our work unveils for the first time a patient-relevant epigenetic mechanism, impinging on H3.3 deposition, as a major regulatory point of DCCs’ cell fate at secondary organs controlling both entry of DCC’s into dormant state as well as their reactivation and thriving as overt metastasis. Citation Format: Stanislav Drapela, Cristina Megino-Luque, Rojan Chimeh Rad, Devesh Raizada, Nadir Sarigul, Didem Ilter, Brian J. Czerniecki, Jose Javier Bravo-Cordero, Ana P. Gomes. Microenvironment driven dynamic deposition of histone H3.3 controls entry and exit from dormancy in disseminated cancer cells [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A013.

Abstract C012: Dissemination of retrotransposable elements from the non-coding genome in tumor-derived extracellular vesicles target stromal and immune cells to induce local and systemic inflammation

Abstract The majority of the human genome (>70%) contains non-coding DNA consisting of retrotransposable elements (RTE), such as LINE-1, SINE/Alu elements, human endogenous retroviruses (HERV), and satellite repeat DNA (Hsat2 and Hsat3). The expression of these elements is suppressed in normal adult tissues but are abnormally expressed in many cancers. Another key mechanism in cancer initiation and progression is the release of tumor-derived extracellular vesicles (EV) that are long-distance communication vehicles propagating signals from tumors inducing metabolic changes, immune dysregulation and promoting metastases across the body. Our work has uncovered a link between RTE, HERV and Hsat expression in cancer and EV in driving tumor progression and immune dysregulation. W hole transcriptome sequencing of EV derived from several different cancer cell lines and patient samples, including Ewing sarcoma, osteosarcoma, prostate, pancreatic, and breast cancer found that RTE, HERV and Hsat2,3 transcripts are highly enriched in EV versus coding region transcripts and in much higher abundance than in the tumor cell themselves. Tumor-derived EV contained dsRNA, dsDNA and RNA:DNA hybrids from these non-coding regions. Plasma EV isolated from both metastatic and non-metastatic patients also showed an enrichment of these RTE, HERV and Hsat2,3 elements and clearly differentiated healthy, normal donor EV that had little or no detectable signal. Evidence of local dissemination of these non-coding elements in EV was also found in vivo in tumor xenografts that showed transfer of Hsat2,3 transcripts into the murine stroma that naturally lack these satellite repeats. Treatment of fibroblasts and myeloid cells with tumor-derived EV triggered innate immune responses via type I IFN and pro-inflammatory cytokines, including IL-1beta, IL-6, IL-8, and TNFalpha owing to the pathogen-like nucleic acid sequences (viral mimicry) of these elements. These EV-induced chronic inflammatory effects were mainly induced through the cGAS-STING nucleic acid sensing pathway. Evidence of DNA damage in stromal fibroblasts and induced senescence was also found as a result of EV treatment. A key element of RTE is the expression of LINE-1 and HERV derived reverse transcriptase (RT) that propagates the action of RTE via RNA:DNA hybrids, dsDNA and retrotransposition in the genome. In a spontaneous estradiol-driven breast cancer model in ACI rats, long-term treatment with an HIV RT inhibitor (lamivudine/3TC) inhibited breast tumor development associated with reduced RTE activation in the mammary gland and in circulating immune cells as well as reduced chronic systemic innate inflammation. Our results suggest that RTE, HERV and Hsat activation, together with their local and systemic dissemination in EV plays an important role in cancer initiation and progression associated with chronic inflammation. We also suggest that abnormal dissemination of these activated non-coding elements in EV may also play a role in "inflammaging" facilitating not only cancer but also other chronic diseases. Citation Format: Laszlo Radvanyi, Valentina Evdokimova, Peter Ruzanov, Zhenbo Zhang, Poul Sorenson, Hendrik Gassmann, Stefan Burdach, Lincoln D. Stein. Dissemination of retrotransposable elements from the non-coding genome in tumor-derived extracellular vesicles target stromal and immune cells to induce local and systemic inflammation [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C012.

Abstract C025: Identification of cell-cell signaling programs across the tumor-tumor microenvironment ecosystem and associated with clinical status in neoadjuvant osimertinib treated patient samples revealed by spatial profiling

Abstract Lung cancer is the leading cause of cancer mortality, and despite improvements in treatment, tumors typically respond incompletely and resume growth after acquisition of drug resistance. Recent completion of a neoadjuvant osimertinib Phase II trial treating patients with surgically resectable stage I-IIIA EGFR-mutated non-small cell lung cancer (EGFRm NSCLC) (NCT03433469) (Blakely et. Al, JCO 2024) has highlighted the importance of further identifying non-genomic mechanisms of persistence and resistance to targeted therapy. Here we analyzed these patient samples to identify transcriptionally regulated signaling patterns enriched at Residual Disease (RD) after neoadjuvant osimertinib treatment compared to treatment naïve samples (TN), as well as signaling patterns enriched at RD in patients who ultimately develop disease recurrence after surgical resection compared to those who remain disease-free. Spatially resolved transcriptomic sequencing was performed, using the 10X Genomics Visium platform, on 36 tissue sections (n=9 TN, n=19 RD, n=4 Progressive Disease (PD), n=4 Tumor Adjacent Normal), from 25 patients. TN and PD samples were from standard-of-care surgical resections. 18 of 19 RD samples were from NCT03433469. The Visium array spots that tile the sequencing capture area are 55 µm in diameter, and thus can contain an estimated 1-10 cells within each array spot. After quality control, 91,582 array spots remained for downstream analysis. We identified high confidence tumor array spots annotated both as “Cancer” by a board-certified pathologist and with tumor characteristic copy number variations. Through dimensionality reduction clustering, we identified 10 major array spot clusters, including the high confidence tumor array spot cluster. These clusters were further subset into 44 high resolution clusters of array spot niches, 32 of which were shared across at least nine patients. Because array spots are not single-cell resolution, these niches represent spots with similar mixed cell type composition and transcriptional signatures. We identified significant increases in the CCL14+ Endothelial Cell Niche, CXCL2+ Endothelial Cell Niche, Lymphocytes + Endothelial Niche, and CXCL12+ Fibroblast Niche in RD samples compared to TN. We identified a cell signaling program defined by spatially co-expressed ligand-receptor pairs associated with focal adhesion, enriched in PD samples. This same pattern was enriched in RD samples from patients who had recurrent disease after surgical resection compared to RD samples from patients who remained disease free. These data describe an increase in immune trafficking in RD samples, as well as identify an EGFR- alternative signaling pathway correlating with osimertinib resistance. Identification of spatially resolved, differential architectural organization and signaling patterns in RD and PD states will expand our understanding of targeted therapy resistance in EGFRm NSCLC, with the potential to identify additional clinically actionable targets. Citation Format: Whitney Tamaki, Daniel L. Kerr, Wei Wu, Grant Eilers, Anatoly Urisman, Yu-Ting Chou, Philippe Gui, Shigeki Nanjo, Johannes R. Kratz, David M. Jablons, Trever G. Bivona, Collin M. Blakely. Identification of cell-cell signaling programs across the tumor-tumor microenvironment ecosystem and associated with clinical status in neoadjuvant osimertinib treated patient samples revealed by spatial profiling [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C025.

Abstract B007: Identification of Asporin as a HER3 ligand exposes a therapeutic vulnerability in metastatic prostate cancer

Abstract Background: Rates of prostate cancer incidence and advanced-stage diagnoses are increasing. Despite curative-intent therapies, nearly all patients with advanced disease progress to metastatic castration-resistant prostate cancer (mCRPC), a lethal form of the disease. There is an urgent unmet need to understand the mechanisms driving prostate cancer progression and identify alternative therapies for patients with mCRPC. It is well-established that cancer-associated fibroblasts (CAF) in the tumor microenvironment secrete factors that enable cancer cells to establish metastases. Asporin (ASPN) is an extracellular protein secreted by a subset of CAF and is associated with worse oncologic outcomes, yet the mechanisms remain poorly understood. In this study, we sought to identify the molecular interactions between the CAF-secreted ASPN and metastatic prostate cancer cells. Methods: ASPN-induced HER2/HER3 activation and downstream signaling was identified by RNA-sequencing and then confirmed by immunoblotting in multiple human metastatic prostate cancer cell lines. Binding interactions were assessed computationally by AlphaFOld2 with Rosetta refinement and substantiated by co-immunoprecipitation assays. CRISPR-cas9 targeting of HER2 and HER3 and therapeutic inhibition of HER2 with Tucatinib were used to determine the role of HER2/HER3 in ASPN-induced signaling and migration. The efficacy of Tucatinib and antibody-drug conjugates (ADC) targeting HER2 (Trastuzumab-deruxtecan) and HER3 (Patritumab-deruxtecan) were assessed in multiple metastatic prostate cancer cell lines in vitro. Trastuzumab-deruxtecan was assessed in PC3 xenografts in vivo. Prostate cancer metastases from 33 patients were assessed by IHC for HER2 and HER3 and by RNAscope for ASPN. Results: We report that ASPN is a novel ligand of HER3 and induces HER3 heterodimerization with its preferred dimerization partner, HER2. ASPN activates established ErbB-associated pathways including Phosphoinositide 3-kinase (PI3K), Mitogen-activated protein kinase (MAPK), and calcium signaling, in multiple metastatic prostate cancer cell lines to promote cell migration. Genetic and molecular inhibition of HER2/HER3 mitigates ASPN-induced signaling and cell migration, suggesting these receptors are required for paracrine activation by ASPN. Importantly, small molecule and ADC therapies targeting HER2/HER3 significantly diminished prostate cancer cell growth in vitro, with enzalutamide-resistant cells showing increased sensitivity. Trastuzumab-deruxtecan nearly resolved tumors in an in vivo xenograft model. Lastly, ASPN+ CAF in the TME of HER2/HER3-expressing metastatic prostate cancer is frequently observed in patient samples, supporting the clinical relevance of these findings. Conclusions: Collectively, these findings indicate ASPN functions as a HER3 ligand to induce cellular migration, and inhibition with anti-HER2/HER3 therapies highlights potential clinical utility for patients with HER2-expressing metastatic prostate cancer. Citation Format: Amanda B. Hesterberg, Hong Yuen Wong, Jorgen Jackson, Monika Antunovic, Brenda L. Rios, Evan Watkins, Riley E. Bergman, Brad A. Davidson, Sarah E. Ginther, Diana Graves, Elliott F. Nahmias, Jared A. Googel, Lillian B. Martin, Violeta Sanchez, Paula Gonzalez Ericsson, Quanhu Sheng, Benjamin P. Brown, Jens Meiler, Ben H. Park, Kerry R. Schaffer, Jennifer B. Gordetsky, Paula J. Hurley. Identification of Asporin as a HER3 ligand exposes a therapeutic vulnerability in metastatic prostate cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B007.

Abstract C002: CKLF attracts CCR4-expressing CD4+ cells to foster immune repression and tumor aggressiveness in MYCN-driven neuroblastoma

Abstract Neuroblastoma, especially those with aberrant MYCN activation, often harbor an immunosuppressive microenvironment to fuel malignant growth and trigger treatment resistance. Despite this knowledge, there are no effective strategies to tackle this problem. Here we combined analyses of human neuroblastoma with live tracking and functional studies of the tumor microenvironment (TME) in zebrafish. We identified chemokine-like factor (CKLF) as a key driver of MYCN-mediated immunosuppression and neuroblastoma aggression. We showed that human MYCN-activated neuroblastoma upregulates and secretes CKLF, which is a reliable predictor of poor patient survival. Analysis of primary patient samples demonstrates a strong positive association between MYCN and CKLF expression in neuroblastoma cells together with the enrichment of FOXP3+ T cells in the TME. Taking advantage of in vivo zebrafish models of MYCN-driven neuroblastoma that resemble human high-risk disease, we demonstrated that cklf overexpression in zebrafish neural crest cells induces an immunosuppressive TME while promoting rapid tumor onset and progression. We also demonstrated that as early as the premalignant stage, tumor cells secrete CKLF to attract CCR4-expressing Cd4+ cells to induce immunosuppression and tumor aggression. Conversely, genetic depletion of cklf in tumor cells reduces the recruitment of Cd4+ cells to the TME while increasing cytotoxic Cd8+ and natural killer cells infiltration, inhibiting neuroblastoma development in zebrafish. Our work provides the first example that MYCN can activate CKLF to allure CD4+ immune cells to the TME and incite immunosuppression, positioning CKLF as a potential novel immunotherapeutic target for the treatment of MYCN-driven high-risk neuroblastoma. Citation Format: Xiaodan Qin, Hui Feng, Andrew Lam, Xu Zhang, Satyaki Sengupta, Bryan Iorgulescu, Sanjukta Das, Zhenwei Zhou, Tao Zuo, Grace Meara, Madison Rager, Alexander Floru, Hongru Ni, Chinyere Kemet, Divya Veerapaneni, Daniel Kashy, Liang Lin, Kenneth Lloyd, Lauren Kwok, Kaylee Smith, Raghavendar Nagaraju, Rob Meijers, Craig Ceol, Ching-Ti Liu, Sanda Alexandrescu, Catherine J. Wu, Derin Keskin, Rani George. CKLF attracts CCR4-expressing CD4+ cells to foster immune repression and tumor aggressiveness in MYCN-driven neuroblastoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C002.

Abstract B023: Regulatory T (Treg) cell contributes to tumor cell dissemination via extracellular matrix (ECM) remodeling, which is driven by TAMs in an IFNg-dependent manner

Abstract Background: The extracellular matrix (ECM) is a highly organized non-cellular network consisting of structural proteins, growth factors, cytokines and other secreted molecules. The ECM is highly dynamic and is a critical player in the regulation of local invasion and metastasis. The ECM network is ever-changing and an important immunosuppressive component of the tumor microenvironment (TME). However, the reciprocal effects of the immune system on the tumor-associated ECM are elusive and largely unexplored. Regulatory T (Treg) cells function to enforce peripheral tolerance and are potent suppressors of tumor immunity. We have previously shown that Treg cells promote tumor growth in murine breast cancer models by favoring alternative activation of tumor-associated macrophages (TAMs) via suppression of IFN-g. Aims: In this work, we sought to assess whether Treg cell-mediated immune suppression is associated with changes in the ECM, and whether those ECM changes functionally impact metastatic dissemination. Further, we assessed the requirement of TAMs and IFN-g in the ECM remodeling. Design Methods: In this study, we used spontaneous and transplantable models of breast cancer susceptible to genetic ablation of Treg cells. We used a combination of histopathological analysis, tumor decellularization, bioengineering 3D-chip modeling, in vivo manipulations and bioinformatic analysis, to evaluate remodeling of the ECM, cancer cell invasive behavior and metastatic dissemination. Results Summary: Treg cell ablation resulted in significant ECM remodeling, with reduced amounts and organization of collagen fibers, and increased amounts of fibronectin and laminin. Tumor cells seeding on Treg cell ablated tumor- derived decellularized ECM matrices results in reduced epithelial-mesenchymal transition (EMT) transcription factors, and profound impairment of collective migration. In vivo, Treg cell ablation in a neo-adjuvant setting followed by primary tumor resection resulted in significant reduction of circulating tumor cells (CTC) and impairment of lung metastatic disease. Importantly, we demonstrated that Treg cell ablation-driven changes in the matrisome correlate with long-term improved survival in a cohort of breast cancer patient samples. Through genetic knock-out models and in-vivo neutralization, we observed that Treg cell-dependent changes in ECM-related phenotypes are dependent on IFN-g-signaling. Single-cell RNA-sequencing (scRNA-seq) of murine breast tumors revealed that the matrisome signature is highly upregulated among TAMs, compared to other TME cell types. Lastly, using conditional genetic knock-out models we show these IFN-g-dependent changes are mostly driven by TAMs. Conclusions: Altogether, we identified a novel metastasis-promoting effect of Treg cells in the breast cancer microenvironment through regulation of ECM dynamics beyond their described effects on primary tumor growth. Citation Format: Ailen D. Garcia-Santillan, Jessanne Y. Lichtenberg, He Shen, Jasmine M Rodriguez, Jonathan Barra, Nicholas M Clark, Wei Du, Leandro M Martinez, Ashley D Hadjis, Taylor Calicchia, Mikhail G Dozmorov, Jose J Bravo-Cordero, Amy L Olex, Priscilla Y Hwang, Paula D Bos. Regulatory T (Treg) cell contributes to tumor cell dissemination via extracellular matrix (ECM) remodeling, which is driven by TAMs in an IFNg-dependent manner [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr B023.

Abstract C023: P21-positive senescent stromal cells promote prostate cancer immune suppression and progression that can be reversed by senolytic therapy

Abstract Cellular senescence is historically viewed as a tumor-suppressive cell cycle arrest program to limit outgrowth of pre-malignant cells. However, emerging evidence suggests senescent cell persistence contributes to immune suppression and cancer progression. Using prostate cancer patient samples and murine models, we find that p16+ senescent cells accumulate throughout malignant progression and are associated with immune suppression and poor survival. p16 ablation in mice eliminated senescent epithelial cells and reversed immune suppression mediated by immature myeloid cells but not prostate tumorigenesis. Single cell sequencing revealed an additional population of senescent p21+ fibroblasts and myeloid cells. Targeting BCL-xL or PD-L1 induced during senescence could remove both p16+ epithelial and p21+ stromal senescent cells, reactivate T cell immunity, and block tumor initiation as well as progression in advanced prostate cancer models. Our findings demonstrate that targeting heterogenous senescent populations can not only prevent malignant transformation but also yield therapeutic benefits in advanced prostate cancers through activating anti-tumor immunity. Citation Format: Lin Zhou, Kelly D. DeMarco, Katherine C. Murphy, Zhenpeng Wu, Jinping Li, Junhui Li, Calvin Johnson, Zhong Jiang, Shi Bai, Tianyi Ye, Karl Simin, Lihua Julie Zhu, Jason R Pitarresi, Hong Wu, Marcus Ruscetti. P21-positive senescent stromal cells promote prostate cancer immune suppression and progression that can be reversed by senolytic therapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr C023.

Abstract PR010: TRPV1+ sensory innervation as a novel driver of ovarian cancer progression

Abstract Introduction: A primary challenge currently faced in ovarian cancer (OVCA) treatment is that patient prognoses remain poor despite current therapeutic interventions. Overall survival for OVCA patients with advanced disease is <30%, and most patients recur within 5 years. As such, there is a critical need for new therapies that can overcome OVCA chemoresistance and produce meaningful increases in patient survival. Recent efforts that have targeted the tumor microenvironment (TME), such as immune checkpoint inhibitors, have been successful in some cancers but have limited therapeutic benefit when used to treat OVCA. Thus, new TME targeting therapies must be developed to effectively treat OVCA patients. A novel TME component ripe for therapeutic targeting are the nerve fibers that infiltrate tumors. Recent studies in several cancers have shown that tumor innervation can promote tumor growth/metastasis. However, in ovarian cancer the role of innervation in promoting cancer progression remains a gap in knowledge. Here we show that Transient Receptor Potential Cation Channel Subfamily V Member 1 (TRPV1)+ sensory innervation plays a significant role in driving ovarian cancer progression. Methods: We performed IHC staining to determine the extent of TRPV1+ nerve infiltration in OVCA vs normal reproductive tissue in patients. We examined the ability of OVCA cells to promote tumor innervation using a neurite outgrowth assay. We utilized both syngeneic and patient derived xenograft (PDX) mouse models of ovarian cancer metastasis, where mouse or human OVCA cells were injected intraperitoneally, to explore the functional role of TRPV1+ sensory nerves in OVCA. TRPV1+ sensory nerves were ablated genetically using TRPV1 driven expression of diphtheria toxin alpha (DTA) or chemically using resiniferatoxin. TRPV1+ sensory nerves were activated pharmacologically using capsaicin. Results: Analysis of patient samples showed that TRPV1+ sensory innervation is much higher in ovarian tumors vs benign reproductive tissue. We found that conditioned media from OVCA cells was able to promote neurite outgrowth of dissociated mouse sensory neurons. Ablation of TRPV1+ sensory nerve fibers in vivo caused reduced tumor burden and prolonged survival in our syngeneic and PDX OVCA mouse models. Stimulation of TRPV1+ sensory nerves with capsaicin accelerated OVCA growth and decreased survival in tumor bearing mice. Conclusions: Our results establish TRPV1+ sensory innervation as a novel driver of OVCA growth/metastasis and a potential therapeutic target for OVCA treatment. Significance to tumor microenvironment field: Our data add to a growing body of evidence that sensory nerves are pro-tumorigenic in multiple cancer types and could be therapeutically targeted for cancer treatment. Citation Format: Matthew Knarr, Katherine Cummins, Dusan Racordon, Hunter Reavis, Timothy Lippert, Ryan Hausler, Priyanka Rawat, Jamie Moon, Dave S.B. Hoon, Roger Greenberg, Paola Vermeer, Ronny Drapkin. TRPV1+ sensory innervation as a novel driver of ovarian cancer progression [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr PR010.

Abstract A002: Dissecting the brain metastatic microenvironment to uncover immune and molecular correlates of response to immunotherapy

Abstract Despite promising results with immune checkpoint blockade (ICB) therapy, brain metastases (BrM) remain a deadly complication for cancer patients. Understanding the highly specialized brain metastatic tumor microenvironment (BrTME) is crucial for identifying determinants of response, however, progress has been hindered by limited access to patient samples and scarcity of relevant preclinical models. Here, we developed two mouse melanoma BrM models by intracardiac injection of cells derived from our previously established M4-B2905 melanoma mouse cell line. We characterized their mutational landscape and performed single-cell phenotypic and transcriptomic analysis, demonstrating that these models recapitulate the cellular and molecular features of human melanoma BrMs. Comparative and interactome analysis of our models revealed key factors contributing to ICB response and resistance. We found that the responsive model (BR1) was characterized by tumor cells that polarize microglia toward reactive states via inflammatory programs and response to IFN signaling. These microglia express high levels of antigen presentation and immunostimulatory molecules, triggering T cell recruitment and activation and promoting ICB therapy response. In contrast, in the resistant model (BR3), the tumor cells express neurological molecular signatures and ligands that sustain microglia homeostasis. This results in poor T cell infiltration predominantly composed of naïve cells, evading immune reaction and promoting ICB resistance. While we showed that systemic ICB therapy induced BrTME changes in both models, differences between responder and resistant models were maintained, emphasizing the importance of tumor cell-intrinsic programs in dictating the BrTME. We validated the translational relevance of our findings and demonstrated that BR1 signatures positively correlate with T cell infiltration and are associated with improved patient outcomes, whereas BR3 signatures negatively correlate with T cells and are found in patients with worse prognosis. Here we address an important challenge in the field by providing clinically relevant BrM models that recapitulate both the cellular and molecular features of human disease and the variability of ICB response seen in patients. We further reveal mechanistic insights into BrM ICB response and identify potential therapeutic targets to modulate the BrTME. Citation Format: Amelie Daugherty-Lopes, Eva Perez-Guijarro, Vishaka Gopalan, Jessica Rappaport, Quanyi Chen, April Huang, Khiem C. Lam, Sung Chin, Jessica Ebersole, Emily Wu, Gabriel Needle, Isabella Church, George Kyriakopoulos, Shaojun Xie, Yongmei Zaho, Charli Gruen, Antonella Sassano, Romina E Araya, Andres Thorkelsson, Cari Smith, Maxwell P. Lee, Sridhar Hannenhalli, Chi-Ping Day, Glenn Merlino, Romina S. Goldszmid, Shaojun Xie. Dissecting the brain metastatic microenvironment to uncover immune and molecular correlates of response to immunotherapy [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Tumor-body Interactions: The Roles of Micro- and Macroenvironment in Cancer; 2024 Nov 17-20; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(22_Suppl):Abstract nr A002.

Revisiting tuberculosis diagnosis: the prospect of urine lipoarabinomannan assay as a diagnostic tool in people living with human immunodeficiency virus

Abstract Background Tuberculosis, since its discovery has become a global health burden, continuously spreading across the nations of the earth with increased mortality. Its effect on human immunodeficiency virus (HIV) progression and immune cell deterioration cannot be overlooked. The widespread use of traditional and molecular TB diagnostic methods has been hindered by several factors. Nonetheless, the development of a rapid, sensitive, timely, non-invasive diagnostic protocol could revolutionise the diagnostic era and halt the spread of this infectious agent. It could also help in the early diagnosis of the infection in poorly developed areas. The detection efficacy of urine lipoarabinomannan assay as a prospect in tuberculosis diagnosis in HIV-positive patients was assessed in this study. Urine samples were collected into a wide-mouthed universal container from HIV-positive patients with signs and symptom of tuberculosis and HIV advanced disease. Alere determine urine lateral flow—LAM test was used for the detection of LAM antigen in urine samples of HIV-positive patients. The CD4 count of the HIV-positive patients was also documented. Results A total of 85 HIV-positive subjects were included in the analysis based on the inclusion criteria. Urinary LAM was reactive in 29 (34.1%) of 85 HIV-positive patients and non-reactive in 56 (69.1%). The majority of the participants had a CD4+ count < 200 cells/µL 60 (70.6%), while others had CD4+ count ≥ to 200 cells/µL 25 (29.4%). There was no statistically significant difference between CD4 count and LAM positivity. Most of the affected age groups in the study were 31–45 years, and females had preponderance in comparison to male subjects. Conclusions The use of urinary LAM in HIV-positive patients is a helpful tool for TB screening. It also has a promising ability for early TB diagnosis in the study group and other TB-associated disease conditions in resource-deprived settings. For the general populace, further research is required to certify its sensitivity and specificity.

Exploring Reciprocal Associations Between Self-Reported Anxiety and Eating Disorder Symptoms Longitudinally: ABivariate Latent Change Score Approach.

Consistent data support an association between anxiety and eating disorders (EDs), and theoretical models of EDs suggest that anxiety may be involved in the etiology and maintenance of ED symptoms over time. However, the directionality of relations between these variables remains under-characterized, particularly within treatment settings. We used bivariate latent change score models to explore longitudinal associations between anxiety and ED symptoms in a sample of ED patients (N = 548, 93.2% female, Mage = 21.16, 78.8% White, 79.6% Non-Hispanic/Latinx) throughout intensive treatment and at 6- and 12-month follow-up. Best-fitting models exploring change in each variable independently (i.e., univariate models) suggested that changes in ED and anxiety symptoms decreased over time, but that change was influenced by an individual's symptom severity at the previous timepoint. Models exploring associations between changes in both variables over time (i.e., bivariate latent change score models) suggested the best fit for a model where both anxiety and ED symptoms at one timepoint were associated with later change in the other. Specifically, parameters within these models suggested that higher levels of anxiety were associated with increased subsequent reductions in ED symptoms, whereas elevations in ED symptoms were associated with decreased later reductions in anxiety. Our findings suggest that anxiety and ED symptoms are intricately related both within and outside of intensive treatment. Future multi-modal research exploring real-time links between anxiety and ED symptoms throughout treatment is critical to extend this work and inform improvements in targeted, mechanistic interventions for this population.

Microorganisms isolated from thermoplastic masks and storage racks in head and neck cancer patients with radiation dermatitis.

Healthcare-associated infections (HAIs) remain a critical public health issue, as they contribute to prolonged treatment duration, increased healthcare costs, and heightened risks of morbidity and mortality. In head and neck cancer patients undergoing radiotherapy, thermoplastic masks (TMs), which come into direct contact with the skin, represent a potential vector for infection. Additionally, the storage racks where these masks are kept may also facilitate microorganism transmission. Our study aimed to isolate and identify microorganisms from infective skin lesions secondary to radiation dermatitis in head and neck cancer patients, as well as from the TMs and storage racks, and to evaluate the antibiotic resistance profiles of the isolated microorganisms. The study included 71 locally advanced head and neck cancer patients who underwent radiotherapy between August 2022 and November 2023. Patients were monitored daily, and their skin evaluations were made according to Common Terminology Criteria for Adverse Events (CTCAE) version 4.0. Grade 2 and 3 radiodermatitis was observed in 29 of these 71 patients. Samples were collected using sterile swabs from the skin lesions on the head and neck area, the inner surfaces of the TM, and the storage rack from 29 patients. Samples were inoculated into enrichment and selective media. After the growing microorganisms were identified, antimicrobial susceptibility was evaluated using conventional methods and automated systems according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) criteria. At least one type of microorganism was isolated from the skin samples of infected patients, and double growth was detected in two patients. Among the samples, 2 were methicillin-resistant coagulase-negative Staphylococcus (MRCNS), 1 was methicillin-resistant Staphylococcus aureus (MRSA), 1 was Candida albicans (C. albicans), 15 were methicillin-sensitive coagulase-negative Staphylococcus (MSCNS), 1 was methicillin-sensitive Staphylococcus aureus (MSSA), 1 was Bacillus subspecies (Bacillus spp.) and 3 were Corynebacterium diphtheriae (C. diphtheriae). Coagulase-negative Staphylococcus strains were isolated from the skin of 14 of 19 patients with grade 2 radiation dermatitis, whereas CNS strains were isolated from only 2 of 10 patients with grade 3 radiation dermatitis. Among the gram-negative bacteria, 3 Pseudomonas aeruginosa (P. aeruginosa), 2 Enterobacter cloacae (E. cloacae), 1 Klebsiella pneumoniae (K. pneumoniae) and 1 Moraxella catarrhalis (M. catarrhalis) strain were isolated. Sixteen (55.1%) of the TMs used in 29 patients and 20 (68.9%) of the storage racks harbored microorganisms, including HAI agents and flora bacteria. Bacteria colonize TMs and storage racks where they are risk factors for secondary skin infections in radiation dermatitis lesions that develop on the skin of head and neck cancer patients. Decontamination procedures should be meticulously applied to surfaces such as TMs and their storage racks during the course of radiotherapy.

Establishing the Patient Acceptable Symptoms State for the Boston Carpal Tunnel Questionnaire in a Postoperative Carpal Tunnel Surgery Population.

Threshold scores for patient acceptable symptom state (PASS) represent the score beyond which a patient considers themselves "well." We aimed to determine PASS thresholds for the symptom severity scale (SSS) and functional status scale (FSS) of the Boston Carpal Tunnel Questionnaire in a sample of patients 1 year following carpal tunnel release. Adults (≥ 18 years) from a single, tertiary-care academic institution were contacted 12 ± 1 months after carpal tunnel release. The Boston Carpal Tunnel Questionnaire and two PASS anchor questions were administered via REDCap-one queried acceptability of their current symptoms, and the other queried function. Participants were classified as being in an acceptable symptom state ("PASS(+)") if they answered "very satisfied" or "somewhat satisfied," whereas those responding "neither satisfied nor dissatisfied," "somewhat dissatisfied," or "very dissatisfied" were classified as "PASS(-)." Threshold values were calculated using three methods: (1) the mean score for PASS(+) participants, (2) the 75th percentile score for PASS(+) patients, and (3) the Youden Index determined using receiver operating curve (ROC) analysis to maximize sensitivity and specificity. The 153 patients included in the study had a mean age of 60 ± 15 years and 60% (94/153) were women. At a mean follow-up of 1.0 ± 0.1 years, SSS and FSS scores were significantly lower (better) for PASS(+) than PASS(-) patients for both anchor questions. PASS estimates ranged from <1.4 to <1.8 for the SSS and from <1.3 to <1.5 for the FSS. All ROC curves produced excellent discrimination (area under the curve > 0.8). We propose PASS thresholds of 1.8 for the SSS and 1.5 for the FSS, derived by the Youden or ROC method, which showed excellent discrimination between PASS(+) and PASS(-) patients. These threshold values can be used to assess whether patient populations have achieved an adequate symptom and functional state.

Prognostic model development using novel genetic signature associated with adenosine metabolism and immune status for patients with hepatocellular carcinoma.

The high mortality rate of hepatocellular carcinoma (HCC) is partly due to advanced diagnosis, emphasizing the need for effective predictive tools in HCC treatment. The aim of this study is to propose a novel prognostic model for HCC based on adenosine metabolizing genes and explore the potential relationship between them. Regression analysis was performed to identify differentially expressed genes associated with adenosine metabolism in HCC patients using RNA sequencing data obtained from a public database. Adenosine metabolism-related risk score (AMrisk) was derived using the least absolute shrinkage and selection operator (LASSO) Cox regression and verified using another database. Changes in adenosine metabolism in HCC were analyzed using functional enrichment analysis and multiple immune scores. The gene expression levels in patient samples were validated using quantitative reverse transcription polymerase chain reaction. Thirty adenosine metabolism-related differentially expressed genes were identified in HCC, and six genes (ADA, P2RY4, P2RY6, RPIA, SLC6A3, and VEGFA) were used to calculate the AMrisk score; the higher the risk scores, the lower the overall survival. Moreover, immune infiltration activation and immune checkpoints were considerably higher in the high-risk group. Additional in vitro experiments validated the enhanced expression of these six genes in HCC. The established predictive model demonstrated that adenosine metabolism-related genes was significantly associated with prognosis in HCC patients.

CT-defined muscle density as a prognostic factor in multiple myeloma undergoing autologous stem cell therapy: a retrospective single center study.

Skeletal muscle quality assessment can be performed by cross-sectional imaging. Skeletal muscle density (SMD) identified to be of prognostic relevance of several clinically outcomes in patients with hematological diseases. The purpose of the present study was to establish the effect of SMD on overall survival (OS) and progression-free survival (PFS) in patients with multiple myeloma (MM). All patients with MM were retrospectively analyzed between 2009 and 2019. 127 patients were included into the analysis. Whole-body computed tomography (CT) was used to calculate skeletal muscle index (SMI), SMD, albumin-gauge score and intramuscular adipose tissue content (IMAC). Overall, 28 patients (22.0%) of the patient sample died. In the discrimination analysis muscle density was higher in non-survivors compared to survivors (mean 30.8 ± 12.5 versus 24.1 ± 15.8, p = 0.03) and IMAC was lower in non-survivors (-0.66 ± 1.8 versus -0.25 ± 0.21, p = 0.01). These differences, however, were not demonstrated in the logistic regression analysis, which could not show prognostic relevance for the investigated muscle density parameters on PFS or OS. CT-defined muscle density parameters have no prognostic relevance on survival in patients with MM undergoing autologous stem cell therapy, which was demonstrated in a comprehensive analysis. These results corroborate previous smaller studies that body composition might have a limited role in this tumor entity.

Abstract B010: Systematical evaluation on alternative splicing in immune-related therapy targets reveals innate and acquired therapy resistance mechanisms in multiple myeloma

Abstract Introduction: Although multiple myeloma (MM) is considered incurable, immune-related therapies are emerging as promising approaches to prolong patient survival. Alternative splicing (AS) has been identified as a mechanism causing therapy resistance to CD19 CAR-T in B-cell malignancies, but no systematic evaluation has been made on the impact towards MM immunotherapy targets. Methods: Utilizing two datasets (MMRF N=852 and IU N=122), we selected high-confidence targets based on high RNA expression (Log2(TPM+1)&amp;gt;3), low toxicity (nTPM&amp;gt;50 in &amp;lt;2 normal tissues and in &amp;lt;2 normal blood cells) and high target potential (&amp;gt;3 surfaceome databases or established immune-therapy targets). Known resistance mechanisms of other therapies, such as immunomodulatory drugs (IMiDs) were also included. AS analysis was conducted for all identified targets. Expression and AS events between patient samples and 19 MM cell lines from DepMap database were also measured. Results: 102 high-confidence targets were identified in MM samples including six existing immunotherapy targets (BCMA, SLAMF7, GPRC5D, CD79A/B and CD38). From these 102 genes, 361 significant AS events were subsequently identified (|dPSI|&amp;gt;0.2, FDR&amp;lt;0.05, &amp;gt;10 supporting reads in &amp;gt;25% samples). One event of interest included an aberrant exon inclusion event in the existing target FCRL5 in ∼10% of newly diagnosed and relapse patient samples, despite being treatment naïve. A cryptic exon between exon 3 and 4 of the canonical transcript was found with higher usage in MM (PSI&amp;gt;0.48) compared to 8 normal bone marrow plasma cell samples (=0.13). Inclusion of this exon led to the switch from three protein-coding transcript variants (FCRL5-201, -202, -203) to a transcript encoding a truncated protein after the first Ig domain (-206). The AS event in treatment-naïve patients may lead to the selection of this variant in treated patients as a mechanism of therapy resistance. Another key event was detected in CRBN, which encodes the target of IMiDs including lenalidomide. Serial samples in one patient treated with lenalidomide identified a novel splice junction in CRBN in the later sample (dPSI=0.2). The novel splice junction led to the skipping of exon 8 encoding the LON domain, which is essential for maintaining the functional conformation of the IMiD-binding site. Lack of exon 8 will disrupt LON domain integrity, indicating a potential AS-induced resistance mechanism. Interestingly, the novel splice junction was found in 70% relapsed samples (&amp;gt;10 supporting reads), 60% of which were with high exon skipping level (PSI&amp;lt;0.5). Conclusion: We have identified potential innate and acquired AS mechanisms that affect patient response towards immune-related therapies, highlighting the importance of conducting RNA-based diagnostics for MM patients. Citation Format: Enze Liu, Travis S Johnson, Parvathi Sudha, Habib Hamidi, Faiza Zafar, Vivek S Chopra, Rafat Abonour, Brian A Walker. Systematical evaluation on alternative splicing in immune-related therapy targets reveals innate and acquired therapy resistance mechanisms in multiple myeloma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr B010.

Abstract PR009: mascRNA directs nutrient-insensitive activation of the LARS-mTOR pathway in breast cancer

Abstract Cellular growth and metabolism are tightly regulated by nutrient availability, yet cancer cells frequently lose these controls, enabling unchecked proliferation even in the absence of sufficient nutrients. While non-coding RNAs are known to regulate metabolic enzyme expression, their direct role in nutrient-sensing pathways in cancer remains unclear. MALAT1-associated small cytoplasmic RNA (mascRNA) is a 61-nucleotide small RNA with a tRNA-like structure, cleaved from the 3’ end of the long non-coding RNA MALAT1. mascRNA has been shown to promote hepatocellular carcinoma proliferation and enhance protein translation in HEK293 cells, though its underlying molecular mechanism is not fully understood. We assessed mascRNA levels in over 70 human breast cancer patient samples using BaseScope assays and found that mascRNA is detectable in the cytoplasm of tumor cells, but not in normal mammary tissues or stromal cells adjacent to tumors. However, the levels of mascRNA varied significantly among patient samples, irrespective of molecular subtypes or tumor stages, suggesting that mascRNA is associated with other aspects of tumor biology. Functional studies in breast cancer cell lines revealed that mascRNA overexpression promotes cell proliferation, invasion, and metabolic pathways linked to ATP generation. Specifically, mascRNA increases basal glycolysis and mitochondrial oxidative phosphorylation and significantly enhances mitochondrial spare capacity, particularly in triple-negative breast cancer (TNBC) cell lines. We also found that mascRNA overexpression activates both mTORC1 and AMPK, indicating a deviation from the normal negative feedback loop between these two pathways. To dissect the molecular mechanism, we performed mascRNA pull-down assays and mass-spectrometric analyses. We identified RNA splicing factors, tRNA-modifying enzymes, and several aminoacyl-tRNA synthetases as mascRNA-interacting proteins. Among these, leucyl-tRNA synthetase (LARS), a component of the multi-tRNA synthetase complex, is known for its non-canonical role in activating mTORC1 at the lysosomal membrane. We found that, in MDA-MB-231 TNBC cells, mascRNA overexpression led to increased LARS localization to the lysosomal membrane where it can activate mTORC1. Interestingly, while control MDA-MB-231 cells responded to glucose and leucine availability to regulate the lysosomal localization of LARS and mTOR, mascRNA- overexpressing cells constitutively maintained LARS and mTOR localization to the lysosome, as well as mTORC1 phosphorylation, regardless of nutrient status. In summary, our data demonstrate that mascRNA aberrantly activates the LARS-mTORC1 axis in breast cancer cells independent of nutrient levels, likely through direct interaction with LARS, promoting its localization to the lysosome. This suggests that mascRNA enables breast cancer cells, and possibly other cancer types, to sustain uncontrolled growth even in nutrient-deprived conditions. Elevated mascRNA levels may thus represent a highly efficient metabolic adaptation of cancer cells. Citation Format: Bohye Park, Joshua K Stone, Steve Lim, Shuko Harada, Erin Ahn. mascRNA directs nutrient-insensitive activation of the LARS-mTOR pathway in breast cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: RNAs as Drivers, Targets, and Therapeutics in Cancer; 2024 Nov 14-17; Bellevue, Washington. Philadelphia (PA): AACR; Mol Cancer Ther 2024;23(11_Suppl):Abstract nr PR009.

Ancestral retrovirus envelope protein ERVWE1 upregulates circ_0001810, a potential biomarker for schizophrenia, and induces neuronal mitochondrial dysfunction via activating AK2.

Increasingly studies highlight the crucial role of the ancestral retrovirus envelope protein ERVWE1 in the pathogenic mechanisms of schizophrenia, a severe psychiatric disorder affecting approximately 1% of the global population. Recent studies also underscore the significance of circular RNAs (circRNAs), crucial for neurogenesis and synaptogenesis, in maintaining neuronal functions. However, the precise relationship between ERVWE1 and circRNAs in the etiology of schizophrenia remains elusive. This study observed elevated levels of hsa_circ_0001810 (circ_0001810) in the blood samples of schizophrenia patients, displaying a significant positive correlation with ERVWE1 expression. Interestingly, in vivo studies demonstrated that ERVWE1 upregulated circ_0001810 in neuronal cells. Circ_0001810, acting as a competing endogenous RNA (ceRNA), bound to miR-1197 and facilitated the release of adenylate kinase 2 (AK2). The bioinformatics analysis of the schizophrenia datasets revealed increased levels of AK2 and enrichment of mitochondrial dynamics. Notably, miR-1197 was reduced in schizophrenia patients, while AK2 levels were increased. Additionally, AK2 showed positive correlations with ERVWE1 and circ_0001810. Further studies demonstrated that AK2 led to mitochondrial dysfunction, characterized by loss of intracellular ATP, mitochondrial depolarization, and disruption of mitochondrial dynamics. Our comprehensive investigation suggested that ERVWE1 influenced ATP levels, promoted mitochondrial depolarization, and disrupted mitochondrial dynamics through the circ_0001810/AK2 pathway. Circ_0001810 and AK2 were increased in schizophrenia and positively correlated with ERVWE1. Importantly, ERVWE1 triggered mitochondrial dysfunction through circ_0001810/miR-1197/AK2 pathway. Recent focus on the impact of mitochondrial dynamics on schizophrenia development had led to our discovery of a novel mechanism by which ERVWE1 contributed to the etiology of schizophrenia, particularly through mitochondrial dynamics. Moreover, these findings collectively proposed that circ_0001810 might serve as a potential blood-based biomarker for schizophrenia. Consistent with our previous theories, ERVWE1 is increasingly recognized as a promising therapeutic target for schizophrenia.