Malignant Transformation Research Articles

Knocking Down HN1 Blocks Helicobacter pylori-Induced Malignant Phenotypes in Gastric Mucosal Cells and Inhibits Gastric Cancer Cell Proliferation, Cytoskeleton Remodeling, and Migration.

Helicobacter pylori (H. pylori) is implicated in the aberrant proliferation and malignant transformation of gastric mucosal cells, heightening the risk of gastric cancer (GC). HN1 is involved in the development of various tumors. However, precise mechanistic underpinnings of HN1 promoting GC progression in H. pylori remain elusive. The study collected 79 tissue samples of GC patients, including 47 with H. pylori-positive GC and 32 H. pylori-negative controls. Using human gastric epithelial cells (GES-1) and human gastric adenocarcinoma cells (HGC-27), the effect of overexpression / knocking down of HN1 and H. pylori infection was evaluated on cell function (proliferation, migration, apoptosis), cytoskeleton, and expression of cell malignant phenotype factors that promote the malignant biological behavior of cancer cells. The expression of HN1 in GC tissues is higher than that in paracancerous tissue and is closely related to infiltration, lymphatic metastasis, distant metastasis, survival, and H. pylori infection. Downregulation of HN1 effectively hinders the ability of H. pylori strains 26695 and SS1 to promote migration of GES-1 and HGC-27 cells, while lowering the expression of key indicators associated with malignant phenotype. Downregulated GSK3B, β-catenin, and Vimentin after knockdown Integrinβ1, but HN1 expression remained largely unchanged, when HN1 and Integrinβ1 were knocked down, GSK3B, β-catenin, and Vimentin expression were considerably reduced. Our research demonstrated the crucial role of HN1 in H. pylori-induced acquisition of a malignant phenotype in GES-1 cells. Knockdown of HN1 blocked the pathogenic mechanism of H. pylori-induced GC and downregulated the expression of GSK3Β, β-catenin and Vimentin via Integrin β1.

Hypoxia-Challenged Pancreatic Adenocarcinoma Cell-Derived Exosomal circR3HCC1L Drives Tumor Growth Via Upregulating PKM2 Through Sequestering miR-873-5p.

Pancreatic adenocarcinoma (PAAD) is a fatal disease with poor survival. Increasing evidence show that hypoxia-induced exosomes are associated with cancer progression. Here, we aimed to investigate the function of hsa_circ_0007678 (circR3HCC1L) and hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD progression. Through the exoRBase 2.0 database, we screened for a circular RNA circR3HCC1L related to PAAD. Changes of circR3HCC1L in PAAD samples and cells were analyzed with real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferation, migration, invasion were analyzed by colony formation, cell counting, and transwell assays. Measurements of glucose uptake and lactate production were done using corresponding kits. Several protein levels were detected by western blotting. The regulation mechanism of circR3HCC1L was verified by dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays. Exosomes were separated by differential ultracentrifugation. Animal experiments were used to verify the function of hypoxia-derived exosomal circR3HCC1L. CircR3HCC1L was upregulated in PAAD samples and hypoxic PAAD cells. Knockdown of circR3HCC1L decreased hypoxia-driven PAAD cell proliferation, migration, invasion, and glycolysis. Hypoxic PAAD cell-derived exosomes had higher levels of circR3HCC1L, hypoxic PAAD cell-derived exosomal circR3HCC1L promoted normoxic cancer cell malignant transformation and glycolysis in vitro and xenograft tumor growth in mouse models in vivo. Mechanistically, circR3HCC1L regulated pyruvate kinase M2 (PKM2) expression via sponging miR-873-5p. Also, PKM2 overexpression or miR-873-5p silencing offset circR3HCC1L knockdown-mediated effects on hypoxia-challenged PAAD cell malignant transformation and glycolysis. Hypoxic PAAD cell-derived exosomal circR3HCC1L facilitated PAAD progression through the miR-873-5p/PKM2 axis, highlighting the contribution of hypoxic PAAD cell-derived exosomal circR3HCC1L in PAAD.

Identification and validation of an endoplasmic-reticulum-stress-related gene signature as an effective diagnostic marker of endometriosis.

Endometriosis is one of the most common benign gynecological diseases and is characterized by chronic pain and infertility. Endoplasmic reticulum (ER) stress is a cellular adaptive response that plays a pivotal role in many cellular processes, including malignant transformation. However, whether ER stress is involved in endometriosis remains largely unknown. Here, we aimed to explore the potential role of ER stress in endometriosis, as well as its diagnostic value. We retrieved data from the Gene Expression Omnibus (GEO) database. Data from the GSE7305 and GSE23339 datasets were integrated into a merged dataset as the training cohort. Differentially expressed ER stress-related genes (DEG-ERs) were identified by integrating ER stress-related gene profiles downloaded from the GeneCards database with differentially expressed genes (DEGs) in the training cohort. Next, an ER stress-related gene signature was identified using LASSO regression analysis. The receiver operating characteristic curve was used to evaluate the discriminatory ability of the constructed model, which was further validated in the GSE51981 and GSE105764 datasets. Online databases were used to explore the possible regulatory mechanisms of the genes in the signature. Meanwhile, the CIBERSORT algorithm and Pearson correlation test were applied to analyze the association between the gene signature and immune infiltration. Finally, expression levels of the signature genes were further detected in clinical specimens using qRT-PCR and validated in the Turku endometriosis database. In total, 48 DEG-ERs were identified in the training cohort. Based on LASSO regression analysis, an eight-gene-based ER stress-related gene signature was constructed. This signature exhibited excellent diagnostic value in predicting endometriosis. Further analysis indicated that this signature was associated with a compromised ER stress state. In total, 12 miRNAs and 23 lncRNAs were identified that potentially regulate the expression of ESR1, PTGIS, HMOX1, and RSAD2. In addition, the ER stress-related gene signature indicated an immunosuppressive state in endometriosis. Finally, all eight genes showed consistent expression trends in both clinical samples and the Turku database compared with the training dataset. Our work not only provides new insights into the impact of ER stress in endometriosis but also provides a novel biomarker with high clinical value.

Enigmatic echoes: Exploring brainstem neurenteric cysts - A case series and literature review

Introduction and importanceNeurenteric cysts (NCs) are rare congenital anomalies within the central nervous system, originating from the endodermal layer due to inappropriate embryonic notochordal plate and endoderm separation. Despite constituting a minute fraction of CNS tumors, their diverse clinical presentations and brainstem occurrence pose diagnostic challenges. Case presentationThis study presents a series of three brainstem NCs, detailing demographics, clinical presentations, radiological features, and operative findings. Patients aged 2–40 years exhibited varied symptoms including headaches, vomiting, cranial nerve deficits, and motor/sensory deficits. Literature review of 27 cases showed a mean age of 26.8 years, predominantly in females, with diverse cystic characteristics on MRI. Surgical intervention achieved mostly complete resection, with varying outcomes including recurrence and malignant transformation. Clinical discussionThis study sheds light on the rare entity of brainstem NCs, emphasizing their diagnostic complexity. NCs, though constituting a minute fraction of CNS tumors, present a diagnostic challenge due to their diverse clinical presentations and rarity in the brainstem. ConclusionThis study provides insights into brainstem NCs, emphasizing diagnostic complexity and the importance of MRI in accurate diagnosis and surgical intervention. Enhanced collaboration is needed to refine management strategies for these intriguing lesions.

Qualitative and quantitative changes in mitochondrial DNA associated with cervical cancer: A comprehensive review.

Cervical cancer is the fourth most commonly diagnosed cancer in women and is considered a preventable disease, as vaccination and screening programs effectively reduce its incidence and mortality rates. Disease physiopathology and malignant cell transformation is a complex process, but it is widely known that high-risk HPV (hrHPV) infection is a necessary risk factor for cancer development. Mitochondria, cell organelles with important bioenergetic and biosynthetic functions, are important for cell energy production, cell growth, and apoptosis. Mitochondrial DNA is a structure that is particularly susceptible to quantitative (mtDNA copy number variation) and qualitative (sequence variations) alterations that are associated with various types of cancer. Novel biomarkers with diagnostic and prognostic value in cervical cancer can be evaluated to provide higher specificity and complement hrHPV molecular testing, which is the most recommended method for primary screening. In accordance with this, this review aimed to assess mitochondrial alterations associated with cervical cancer in clinical cervicovaginal samples, in order to unravel their possible role as specific diagnostic and prognostic biomarkers for cervical malignancy, and also to guide the understanding of their involvement in carcinogenesis, HPV infection, and disease progression.

Abstract 7072: MYC acetylated lysine residues drive oncogenic cell transformation and regulate select genetic programs for cell adhesion-independent growth and survival

Abstract The MYC oncogenic transcription factor is acetylated by the p300 and GCN5 histone acetyltransferases. The significance of MYC acetylation and functions of specific acetylated lysine (K) residues have remained unclear. Here, we show that the major p300-acetylated K148(149) and K157(158) sites in human (or mouse) MYC and the main GCN5-acetylated K323 residue are reversibly acetylated in various malignant and non-malignant cells. Oncogenic overexpression of MYC enhances its acetylation and alters regulation of site-specific acetylation by proteasome and deacetylase inhibitors. Acetylation of MYC at different K residues differentially affects its stability in a cell type- dependent manner. Lysine-to-arginine substitutions indicate that although none of the acetylated K (AcK) residues is required for MYC stimulation of adherent cell proliferation, individual AcK sites have gene-specific functions controlling select MYC-regulated processes in cell adhesion, contact inhibition, apoptosis, and/or metabolism, and are required for the malignant cell transformation activity of MYC. Each AcK site is required for anchorage-independent growth of MYC-overexpressing cells in vitro, and both the AcK148(149) and AcK157(158) residues are also important for the tumorigenic activity of MYC-transformed cells in vivo. These AcK residues may also preferentially activate transcription via facilitating MYC binding to several cancer-associated target gene promoters and via enhancing RNAP II recruitment. With the knowledge that MYC lysine residues can be acetylated by HATs GCN5 and P300, some HATs and HAT associated cofactors (i.e. YEATS2 and PIN1) are important for MYC recruitment to DNA binding. By identifying MYC acetylation-dependent coregulators and their oncogenic function, we proposed to understand whether and how MYC acetylation residues cooperate with its cofactors and influence malignant transformation in breast cancer cells.Overall, this study will uncover the functions and mechanisms of MYC acetylation in regulation of malignant transformation and the impact on breast cancer initiation and progression. By analyzing deregulated target genes and MYC-relevant coactivators, the MYC AcK site-specific signaling pathways identified may offer new avenues for selective therapeutic targeting of MYC oncogenic activities. Citation Format: Jeffrey J. Pino, Matthew Hurd, Yifan Zhao, Kay Jang, Michael Allevato, Marina Vorontchikhina, Wataru Ichikawa, Ryan Gates, Emily Villalpando, Michael Hamilton, Francesco Failo, Songqin Pan, Yue Qi, Yu-wen Hung, Thomas Girke, David Ann, Victoria Seewaldt, Ernest Martinez. MYC acetylated lysine residues drive oncogenic cell transformation and regulate select genetic programs for cell adhesion-independent growth and survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7072.

Abstract 761: The relationship between ANGPTL4 and epidermal malignant transformation

Abstract High body mass index (BMI) is a risk factor for several types of cancers. Although epidemiology suggests obesity is negatively associated with non-melanoma skin cancer (NMSC), bariatric surgery has been shown to reduce the risk, suggesting a possible role of adipose tissue in the initiation and promotion of skin cancer. To gain mechanistic insight into how adipose tissue drives cutaneous carcinogenesis, we cultured non-tumorigenic mouse keratinocytes (JB6 P+ cells) with or without factors released from murine visceral adipose tissue (mFTF) and performed RNA-Sequencing. Published work demonstrated mFTF induces anchorage-independent cell growth, a surrogate marker for malignant transformation. Transcriptomic analysis demonstrated a significant induction of Angptl4 mRNA in JB6 P+ cells cultured with mFTF for 3 and 8 hours compared to the vehicle-treated cells. ANGPTL4 is an endogenous inhibitor of lipoprotein lipase that modulates free fatty acid delivery to adipose tissue and oxidative tissues such as muscle and liver. The C-terminal protein demonstrates tumor-associated activities such as angiogenesis, metastasis, protection against anoikis, and enhancement of cell survival. Therefore, we hypothesized that the induction of this gene promotes malignant transformation. RNA-seq data was validated in multiple cell models, including primary keratinocytes with human adipose tissue. Immunohistochemistry was used to assess ANGPTL4 expression in 37 actinic keratosis (pre-malignant) and cutaneous squamous cell carcinoma (cSCC) from patients with different BMIs (18.6 - 49.5). Notably, ANGPTL4 was only observed in the suprabasal epidermal layers in normal skin. For samples containing both lesional and perilesional skin, there was an increase in ANGPTL4 expression in the lesional epidermis relative to the normal perilesional skin. Furthermore, ANGPTL4 expression increased from transition to actinic keratosis to cSCC in situ, suggesting that ANGTL4 is induced during malignant transformation as observed in our pre-clinical models. Interestingly, once cSCC developed an invasive component, ANGTPL4 expression was lost in the invasive keratinocytes but persisted in the in situ component. There was no association between ANGPTL4 expression and BMI in lesional tissue. These data suggest that targeting ANTPLT4 may be a novel therapy for the prevention of skin cancer and that ANGPTL4-high patients or cancer patients with obesity may be a critical demographic for potential risk assessment or therapeutic intervention. Future studies will determine the impact of knocking out ANGTPL4 in our models of malignant transformation. Citation Format: Nat Ato Yawson, Jonathan D. Diedrich, Karen T. Liby, Jesse Veenstra, Jamie Jenna Bernard. The relationship between ANGPTL4 and epidermal malignant transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 761.

Abstract 146: Development of a novel pediatric patient-derived xenograft model with THPO and NDUFB3 mutations

Abstract Familial myeloproliferative neoplasms (MPN) of childhood are extremely rare and have propensity towards malignant transformation such as leukemia and lymphoma. Due to the rarity of these cases, few cellular and mouse models are available for understanding the tumor biology. Therefore, the molecular mechanisms of malignant transformation remain poorly understood limiting the therapeutic progress to treat these conditions. Here, we report the development of a novel pediatric patient-derived xenograft (PDX) mouse model harboring mutations in the THPO and mitochondrial subunit NDUFB3 genes and characterization of their functions. THPO is a regulator of hematopoiesis and induces trilineage hematopoiesis through HSPC proliferation while NDUFB3 is a subunit of the mitochondrial complex 1. We isolated malignant cells from an enlarged spleen sample and blood sample from a pediatric patient with TPO mediated MPN and established a PDX model (PDX-2333) that recapitulates the patient’s disease. Short tandem repeat analyses confirmed an exact match between the PDX-2333 tumors and patient samples. Exome and Sanger sequencing analyses were performed to identify mutations. Immunohistochemistry staining was used for tumor characterization. Wildtype (WT) and mutant forms of NDUFB3 genes were cloned into expression plasmids with a puromycin selection marker and stably transfected in HEK-293 cells. Stable clones of HEK-293 overexpressing WT and NDUFB3 mutants were tested for growth and sensitivity to anti-cancer therapies. We established a novel PDX model of lymphomagenesis harboring unique mutations in THPO and NDUFB3 genes. The THPO (c.-52C>T) mutation in upstream open reading frame causes loss of inhibition of THPO mRNA expression. The NDUFB3 (c.23 A>G) mutation results in a change of amino acid from glutamine 8 (E8) to glycine 8 (G8) (Ndufb3_E8) and is highly conserved in many vertebrate species. HEK-293 cell lines stably overexpressing WT or NDUFB3 mutants were tested for growth and their sensitivity to ruxolitinib, a Jak2 inhibitor and doxorubicin, an FDA-approved treatment for leukemia and lymphoma. Our data showed that cells overexpressing Ndufb3_E8 have increased proliferation and are highly resistant to ruxolitinib and doxorubicin in comparison to the WT NDUFB3. Developing a novel pediatric PDX model and exome sequencing allow us to identify novel genes involved in malignant transformation leading to lymphoma development. Our data demonstrated that mutations in the THPO (c.-52C>T) and NDUFB3 (c.23 A>G) genes play a key role in the pathogenesis of a lymphoma and in regulating drug sensitivity. Citation Format: Jonathan Shilyansky, Casandro J. Chan, Kristen L. Coleman, Mariah Leidinger, Sharathkumar Bhagavathi, Anjali Sharathkumar, Po Hien Ear. Development of a novel pediatric patient-derived xenograft model with THPO and NDUFB3 mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 146.

Abstract 1032: Development of a novel companion diagnostic immunohistochemistry antibody for claudin 18.2-targeted therapies

Abstract Background: CLDN18.2, the isoform 2 of CLDN18, is physiologically confined to gastric mucosa tight junctions, the epitopes of which would be exposed on the cancer cell surface upon malignant transformation and is highly expressed in a significant proportion of cancers, e.g., gastric and pancreatic adenocarcinomas, which makes it a promising drug target for cancer therapy. Currently, multiple drug modalities, such as monoclonal antibodies, ADCs, and CARTs targeting CLDN18.2 are being evaluated in clinical trials. A substantial correlation exists between the expression of CLDN18.2 and the efficacy of the these therapies. However, to date, no companion diagnostic (CDx) antibodies that are specific to CLDN18.2 have been approved. Therefore, it is important to promptly develop an anti-CLDN18.2 CDx antibody with a high specificity, sensitivity, and suitability for immunohistochemistry (IHC). In this study, we present the discovery and validation of a novel, highly sensitive IHC antibody that selectively identifies CLDN18.2. Methods: 3 CLDN18.2 specific peptide fragments from extracellular domain of human CLDN18.2 were conjugated with KLH. Antibodies were discovered by immunizing BALB/c and SJL mice with these peptides-KLH conjugates. Screening and selection process was relied on positive ELISA results against the immunogen, as well as FACS and Acumen Explorer Microplate staining of CLDN18.2-experssing cells. Hit antibodies were evaluated for IHC on formalin-fixed paraffin-embedded CHOK1 cells expressing full-length CLDN18.2 or CLDN18.1. The antibodies were further validated on human gastric cancer tissue samples to establish the analytical sensitivity and specificity of the IHC assay. Results: The mAb clone 43F11 exhibited binding to a fusion polypeptide comprising the first extracellular loop of human CLDN18.2 (aa32-53) at a half maximal effective concentration (EC50) of 0.212 nM. 43F11 showed positive cell surface IHC staining on CLDN18.2-experssing cells after fixation but demonstrated no staining on CLDN18.1-experssing cells. The IHC test method was established by utilizing clinical tumor tissues and PDX samples that had predetermined expression levels of CLDN18.2. The 43F11 antibody accurately identified the expression level of CLDN18.2 in the IHC assay, with a minimum concentration of 0.25 μg/mL. When compared to the commercial CLDN18.2 IHC antibody EPR19202, 43F11 demonstrated greater sensitivity, allowing for positive staining on cancer tissues that have significantly lower levels of CLDN18.2 expression. Conclusion: 43F11 exhibits specific recognition of human CLDN18.2 in IHC assays, while showing no reactivity towards CLDN18.1. It demonstrated superior sensitivity compared to the benchmark antibody. These data suggest that 43F11 has the capacity to serve as an effective diagnostic tool for identifying patients who positively express CLDN18.2. Citation Format: Jishun Chen, Suya Bai, Yu Bai, Zaoshun Hu, Peng Chen, Jay Mei, Bo Shan, Bing Hou. Development of a novel companion diagnostic immunohistochemistry antibody for claudin 18.2-targeted therapies [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1032.

Dynamic interplay of nuclear receptors in tumor cell plasticity and drug resistance: Shifting gears in malignant transformations and applications in cancer therapeutics.

Recent advances have brought forth the complex interplay between tumor cell plasticity and its consequential impact on drug resistance and tumor recurrence, both of which are critical determinants of neoplastic progression and therapeutic efficacy. Various forms of tumor cell plasticity, instrumental in facilitating neoplastic cells to develop drug resistance, include epithelial-mesenchymal transition (EMT) alternatively termed epithelial-mesenchymal plasticity, the acquisition of cancer stem cell (CSC) attributes, and transdifferentiation into diverse cell lineages. Nuclear receptors (NRs) are a superfamily of transcription factors (TFs) that play an essential role in regulating a multitude of cellular processes, including cell proliferation,differentiation, and apoptosis. NRs have been implicated to play a critical role in modulating gene expression associated with tumor cell plasticity and drug resistance. This review aims to provide a comprehensive overview of the current understanding of how NRs regulate these key aspects of cancer biology. We discuss the diverse mechanisms through which NRs influence tumor cell plasticity, including EMT, stemness, and metastasis. Further, we explore the intricate relationship between NRs and drug resistance, highlighting the impact of NR signaling on chemotherapy, radiotherapy andtargeted therapies. We also discuss the emerging therapeutic strategies targeting NRs to overcome tumor cell plasticity and drug resistance. This review also provides valuable insights into the current clinical trials that involve agonists or antagonists of NRs modulating various aspects of tumor cell plasticity, thereby delineating the potential of NRs as therapeutic targets for improved cancer treatment outcomes.

Abstract 2028: The triterpenoid CDDO-Methyl ester requires Nrf2 to decrease lung tumor burden and to protect against the toxicity of chemotherapy in experimental lung cancer

Abstract The NRF2 cytoprotective pathway, a drug target for many inflammation-related diseases, regulates immune cell function. While the anti-inflammatory nature of NRF2 activation protects healthy cells from malignant transformation, cancer cells can utilize the pathway to promote resistance to anti-cancer drugs. Up to 30% of human lung adenocarcinomas acquire mutations in either NFE2L2 or its negative regulator KEAP1 which result in constitutive activation of the NRF2 pathway. However, despite our knowledge of the important immunomodulatory effects of NRF2, these effects are not well characterized in the context of cancer. With NRF2 activators now approved for clinical use, it is critical to understand the impact of these drugs in cancer. Triterpenoids including CDDO-methyl ester (CDDO-Me, also known as bardoxolone methyl) are potent pharmacological NRF2 activators with demonstrated anti-cancer activity in preclinical models. In an early-stage preclinical model of lung cancer, CDDO-Me significantly decreased tumor burden in a dose- and Nrf2-dependent manner and improved immune signatures within the tumor microenvironment. However, most human lung cancers are not diagnosed until more advanced stages. To test CDDO-Me in an established tumor intervention model, lung tumors were initiated with vinyl carbamate in A/J WT and Nrf2 knockout (KO) mice. Tumors were allowed to develop for 8 weeks post initiation, after which mice were fed either a vehicle control diet or CDDO-Me (50-100 mg/kg of diet) for an additional 8-12 weeks, alone or in combination with carboplatin and paclitaxel (C/P) at 50 mg/kg and 15 mg/kg, respectively, by IP injection every other week. CDDO-Me significantly (p < 0.05) decreased surface lung tumor counts 35-71% in a Nrf2-dependent manner, and C/P significantly (p < 0.001) reduced tumor burden 53-59% regardless of Nrf2 status. The combination of CDDO-Me + C/P reduced tumor burden in WT lungs by 84% (p < 0.05), more than either agent alone. Nrf2 KO mice had an approximately two-fold increase (p < 0.001) of surface tumors compared to WT mice in both studies, regardless of treatment. C/P reduced tumor burden similarly in Nrf2 WT and Nrf2 KO mice. Interestingly, the combination of CDDO-Me + C/P increased T cell infiltration into the lungs of WT mice, but this change was not observed in groups treated with either agent alone. Importantly, CDDO-Me did not decrease the efficacy of C/P but protected WT mice from mortality and weight loss and lowered white and red blood cell counts. These studies suggest that NRF2 activation in advanced lung cancers can still decrease tumor burden by favorably modulating the immune microenvironment and, importantly, complements the anti-tumor efficacy of conventional chemotherapy while decreasing drug toxicity. Citation Format: Jessica Ann Moerland, Karen T. Liby. The triterpenoid CDDO-Methyl ester requires Nrf2 to decrease lung tumor burden and to protect against the toxicity of chemotherapy in experimental lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2028.

Abstract 5937: KS20226, a first-in-class IRP2 inhibitor, preferentially induces reprogramming of iron metabolism and suppresses tumor growth in colorectal cancer

Abstract Background: Iron homeostasis plays a role in redox activity, mitochondrial function, and cell cycle regulation. Specifically, the dysregulation of iron metabolism is implicated in malignant transformation and cancer progression. Iron regulatory protein 2 (IRP2) is crucial for maintaining balance within iron levels and primarily controls genes associated with iron utilization. Our discovery of KS20226, a first-in-class IRP2 inhibitor, reveals remarkable potential as an effective anti-cancer drug candidate. We have elucidated the mechanisms underlying the therapeutic effects of KS20226, thereby highlighting the feasibility of targeting IRP2 in colorectal cancer (CRC). Methods: The proliferation inhibitory activity of KS20226 was assessed the CCK-8 and 3D Spheroid models. To investigate mitochondrial function, we conducted measurement of oxidative phosphorylation (OCR) and glycoPER. Furthermore, gene expression analysis was performed through RNA sequencing (RNA-seq) using the Illumina HiSeq 2500 system platform (Macrogen Inc.). Differential expressed gene (DEG) analysis was carried out using the R package DESeq2, and pathway enrichment analysis was analyzed using GSEA (v_4.2.3.). For the observation of autophagic morphology, we utilized transmission electron microscopy (TEM), immunofluorescence staining targeting the autophagy marker LC3B, and immunoblotting. Results: KS20226 exhibited a remarkable growth inhibitory effect in 10 different CRC cell lines, with GI50 values ranging from 1 to 10 μM. KS20226 suppressed IRP2 expression and the corresponding occupancy of the iron-responsive elements of ferritin H and transferrin receptor 1, resulting in iron deprivation, and efficiently controlled CRC growth. Pharmacologic inhibition of IRP2 induced reprogramming of mitochondrial respiration, reducing reliance on oxidative phosphorylation. The observed mitochondrial dysfunction induced by KS20226 was correlated with pathway analysis, revealing a decrease in the gene-set for HALLMARK_OXIDATIVE_PHOSPHORYLATION (NES = -1.38, p-value = 0.008) and an increase in the gene-set for POSITIVE_REGULATION_OF_AUTOPHAGY (NES=1.43, p-value=0.016). Immunoblotting demonstrated that KS20226 activated the phosphorylation of AMPK, ULK, and Beclin1 cascade, leading to the autophagic cell death of the CRC cells. Conclusions: The reliance of cancer cells on iron metabolism to drive proliferation has led to the development of therapeutic strategies targeting the inhibition of IRP2. KS20226, a first-in-class IPR2 inhibitor, exhibits distinct therapeutic properties, such as perturbation of mitochondrial iron metabolism and induction of autophagic cell death. Our findings represent important progress toward exploiting IRP2-mediated abnormal iron metabolism in cancer, an unexplored area of research with substantial unmet needs. Citation Format: Jieon Hwang, Areum Park, Chinwoo Kim, Chang Gon Kim, Jaesung Kwak, Byungil Kim, Hyunjin Shin, Minhee Ku, Jaemoon Yang, Ayoung Baek, Jiwon Choi, Hocheol Lim, Kyoung Tai No, Xianghua Zhao, Uyeong Choi, Tae Il Kim, Kyu-Sung Jeong, Hyuk Lee, Sang Joon Shin. KS20226, a first-in-class IRP2 inhibitor, preferentially induces reprogramming of iron metabolism and suppresses tumor growth in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5937.

Abstract 265: Reconstructing the early steps of breast tumor initiation

Abstract Breast cancer screening programs, detect not only the early stages of the disease but also various preneoplastic lesions which are very difficult to predict if and when they may develop into cancer. This uncertainty can lead to over-diagnosis, over-treatment and stress for millions of screened women. As consequence, discovering reliable biomarkers of this evolution could make it possible to monitor these patients appropriately and propose an effective prevention strategy. To meet this challenge, we urgently need to better understand the mechanisms that regulate human mammary homeostasis during early steps of tumor initiation. The hierarchy and the composition of human mammary epithelium, composed of stem, myoepithelial, luminal progenitors and mature luminal cells, are complex. This complexity raises the question of whether a given mammary epithelial cell is equally likely to be the cell-of-origin of breast cancer. Interestingly, increasing evidences show that disruption of lineage integrity can be a precursor of breast tumor initiation, and the basal and the luminal lineages respond differently to a given oncogenic stress and may each follow their own rule towards malignant transformation. These results strongly suggest that each lineage may have its own pliancy to be transformed by a given oncogene, hijacking the inter-tumoral heterogeneity observed in breast cancers. The objectives of this study are to develop a model to reconstruct the early steps of breast tumor initiation and understand the interplay between the initiating oncogenic event and the cell-of-origin. To answer these questions, we used a human mammary epithelial cell lines (HME) that maintains a cellular hierarchy with mammary stem cells (MaSC) and luminal cells (LC). Upon oncogenic expression of HRASG12V or c-Myc, we observed different modifications of cell homeostasis, with altered proportions of the lineages populations in the cell line. Depending on the oncogenic stress induced, we also demonstrated a modification in the morphology and the cellular composition of HME organoids, as well as in the capacity to form tumors. HRASG12V induces increase of MaSC compartment, formation of more branched organoids and generate aggressive basal-like tumors. Conversely, c-MYC leads to an almost loss of MaSC and formation of more proliferative unbranched organoid and generate tumors with limited growth. To address more precisely how cell-of-origin and lineage plasticity influence malignant transformation, we are developing for the first time a lineage tracing model in human mammary epithelium with HME. Moreover, a single cell RNA-seq was performed at different early time points during HME cellular differentiation in homeostasis and upon oncogenic stress to decipher the molecular mechanisms that underpin the very earliest steps of breast tumor initiation. Citation Format: Anaïs Grandon, Shuheng Lin, Martin Castagné, Julien Wicinski, Olivier Rosnet, Christophe Ginestier, Emmanuelle Charafe-Jauffret. Reconstructing the early steps of breast tumor initiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 265.

Abstract 7545: Epigenetic plasticity in rewiring DNMT1/UHRF1-RB1- NFkB signaling circuit regulates asbestos-induced mesothelial malignant transformation

Abstract The exact mechanisms underlying the causal relationship between asbestos exposure and malignant mesothelioma (MM) have yet to be elucidated. Widespread genomic and epigenomic alterations are being implicated in rewiring of oncogenic signaling networks which may contribute to initiation and progression of MM. In the present study, we examined the molecular profiles of mesothelial cells exposed to asbestos in-vitro and found that asbestos-induced activation of DNMT1/UHRF1 mediated epigenetic repression of RB1 in normal mesothelial cells as well as mesothelioma cells via promoter-specific methylation mechanisms. RB1, as a noncanonical transcription factor, was capable of also negatively modulating the transcriptional activities of DNMT1/UHRF1 mesothelium and mesothelioma. Functioning as one of the downstream effectors of RB1, NFkB was also involved in the transcriptional regulation of DNMT1/UHRF1 directly in a promoter-selective manner and played a pivotal role in the acute as well as chronic functional and phenotypic changes of mesothelial cells following asbestos exposure. Pharmacological interference of the dysregulated RB1-DNMT1/UHRF1- RB1-NFkB signaling circuit constitutively arrested the invasive growth of MPM cells. In-vivo studies using FVB genetic background wild-type and Bap1+/- mice further revealed involvement of epigenetically dysregulation of the RB1-DNMT1/UHRF1- RB1-NFkB signaling circuit during asbestos-induced malignant transformation of mesothelial cells. Taken together, our data are the first to describe that asbestos epigenetically rewires the RB1-DNMT1/UHRF1- RB1-NFkB signaling circuit during mesothelioma development and suggest potential novel strategies to reverse these epigenetic perturbations for MPM treatment in the clinic. Citation Format: Sichuan Xi, Xinwei Wu, David M Straughan, Eden C Payabyab, Haitao Wang, Ruihong Wang, Mary Zhang, Shamus R. Carr, Chuong D. Hoang, David S. Schrump. Epigenetic plasticity in rewiring DNMT1/UHRF1-RB1- NFkB signaling circuit regulates asbestos-induced mesothelial malignant transformation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7545.

Abstract 1473: Exposure of arsenic promotes malignant stemness and induces bladder malignancy in preclinical models

Abstract Numerous epidemiological and scientific studies have consistently demonstrated that populations exposed to arsenic (As) concentrations ranging from >10 ppb to 2500 ppb in their drinking water face an elevated risk of urogenital cancers, with a particular emphasis on bladder cancer (BCa). Hence, the goal of the study is to investigate the underlying mechanisms that trigger malignant transformation in the bladder using physiologically relevant arsenic concentrations observed in BCa patients. In our results, we observed significantly elevated levels of arsenic in the urine of BCa patients, ranging from 20 to 50 mg/L, in stark contrast to the levels observed in healthy controls (>10 mg/L) and the recommended guidelines set by the Environmental Protection Agency (EPA) and Centers for Disease Control and Prevention (CDC). We used a median physiological concentration of arsenic (30 PPM) in drinking water-induced bladder hyperplasia in male and female mice over six months. Likewise, chronic exposure of healthy bladder epithelial cells (TRT-HU1) to similar arsenic concentrations (250nM:30 PPM) for 12 months resulted in malignant transformation, and arsenic-transformed cells (AsT) were capable of inducing tumors in xenografted and orthotopic models. Nonetheless, the molecular mechanism responsible for this malignancy remains to be elucidated. Our molecular analysis has pointed towards the activation of stem cells, notably ALDH1A1 (with a 50,000-fold increase), as a pivotal factor driving this transformation. Furthermore, our research has demonstrated that the activation of ALDH1A1 is contingent on the induction of Metal Response Element-Binding Transcription Factor-1 (MTF1). Consequently, silencing MTF1 inhibited the expression of ALDH1A1 and its associated malignant properties in As-transformed cells, strongly suggesting that MTF1 functions as the master regulator in As-induced bladder carcinogenesis. We have also observed similar molecular signatures (MTF1 and ALDH1A1 expression) in arsenic-exposed versus non-exposed mice and bladder cancer patients. In conclusion, our studies suggest that activation of stem cells is a critical step in arsenic-induced bladder carcinogenesis. Citation Format: Bhawna Tyagi, Mohit Vashishta, Neha Tyagi, Balaji Chandrasekaran, Vaibhav Shukla, Ashish Tyagi, Chendil Damodaran. Exposure of arsenic promotes malignant stemness and induces bladder malignancy in preclinical models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1473.

Abstract 212: Repression of NKX2-1 promote epithelial-mesenchymal transition and tumor neutrophil recruitment in lung cancer progression

Abstract Background: Malignant transformation is associated with tumor aggressiveness and poor patient outcome. This cellular alteration is due to either activation of oncogenes or the silencing of tumor suppressor genes. NKX2-1 was identified as a lineage-specific gene downregulated in poorly differentiated lung adenocarcinoma (LUAD). However, the molecular mechanism and functional role of infiltrated immune cells in NKX2-1-negative tumors are not clearly understood. Methods: Clinical relevance of NKX2-1 expression and disease status were evaluated by immunohistochemical analysis of LUAD tissue arrays and the overall survival analysis of TCGA databases. In vitro and in vivo experiments were applied to confirm the role and mechanisms of NKX2-1 actions in transformed cells. The secretion of chemokines was evaluated by using chemokine array. Flow cytometry and single-cell RNA sequencing analysis of mouse tumor tissue were used to demonstrate the infiltration of neutrophils in mouse models. Results: Low expression of NKX2-1 was observed in high-grade LUAD tumors. LUAD patients who express a pattern of NKX2-1high/TGF-βlow had better survival outcomes than those with NKX2-1low/TGF-βhigh. Mechanistically, TGF-β induced the downregulation of NKX2-1 which led to enhanced epithelial-mesenchymal transition (EMT), cell motility, and CXC chemokine expression. The high release of these chemoattractants promoted the recruitment of neutrophils. Meanwhile, NKX2-1-dependent suppression of CXC chemokines gene expression may be via repressive histone methylation at the promoter region of CXC chemokines in lung cancer cells. In the in vivo syngeneic LUAD models, exacerbated neutrophil infiltration was noted. Single-cell RNA sequencing and flow cytometry both revealed that neutrophils were recruited via CXCLs/CXCR2 activation in LUAD tumors with NKX2-1 knockdown. Conclusion: Our data showed that NKX2-1 represses tumor growth, metastasis, and neutrophil recruitment via the CXCLs/CXCR2-dependent mechanisms. Notably, targeting CXCR2 in NKX2-1-negative tumors may improve LUAD patient outcomes. Citation Format: Shih-Hwa Chiou, Ping-Hsing Tsai, Mong-Lien Wang. Repression of NKX2-1 promote epithelial-mesenchymal transition and tumor neutrophil recruitment in lung cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 212.

Abstract 1666: A novel sox-based continuous and homogeneous assay for the discovery of inhibitors of inactive and active AKT

Abstract Introduction: The activity of protein kinases plays a critical role in the aberrant activation of oncogenic signaling pathways which can drive tumorigenesis and malignant transformation in cancer. AKT has been shown to be both upregulated and mutated in cancer cells allowing it to serve as a driver of cancer cell growth and progression. Inhibition of AKT activation and activity are both attractive targets for effective cancer drug discovery. Experimental Procedures: We developed continuous, homogeneous assays for unactive AKTs. A peptide substrate, modified with a sulfonamido-oxine fluorophore (Sox), utilizes chelation-enhanced fluorescence to enable a real-time readout of AKT-driven phosphorylation. First, a subset of 30,000 Sox-containing sequences were evaluated for AKT substrate candidates, selecting for assay robustness and specificity. A physiologically relevant peptide substrate was identified and used to develop a kinetic assay to monitor AKT1 activation and activity. Unactive AKT1 was incubated with DOPS/DOPC and PIP3, which mimics the plasma membrane, allowing the PH domain of AKT to bind, leading to a conformational change that enables full activation of AKT by PDK1 and MK2. Upon assay initiation, active AKT phosphorylates the sensor peptide, and the resulting signal is read in kinetic mode using a fluorescence intensity readout. First derivative plots for each progress curve were generated; the slope of the linear regions of each plot, representing acceleration towards a steady-state, were used to determine relative rates of activation for each AKT. Results: We developed a novel assay for AKT activation and substrate phosphorylation utilizing AQT0076, DOPS/DOPC, PIP3, PDK1, and MK2. With a mix of classical AKT inhibitors and allosteric inhibitors that rely on an inactive “PH-in” conformation, we demonstrated inhibition and quantified inhibitor potency of both active “PH-out” AKT activity and inactive “PH-in” AKT activation via dose-response measurements of steady-state rate and rate acceleration, respectively. Conclusions: A robust, homogeneous assay was developed to simultaneously monitor AKT activation and substrate phosphorylation kinetically over time. Through a continuous assay, we captured both steady-state rates and rate acceleration as a function of inhibitor concentration, allowing for accurate quantitation of both classes of AKT inhibitors in a single experimental format. With some inhibitors, we observed potencies that matched reported literature values, while with others we observed marked differences that may reflect a more physiological context that could translate through to higher efficacy in the clinic. This novel assay format provides a new tool that can be used in drug discovery to generate more effective next generation inhibitors of both AKT activation and subsequent substrate phosphorylation to prevent cancer cell growth and progression. Citation Format: Susan Cornell-Kennon, Daniel Urul, Matthew Hakar, Hayley McMahon, Khanh Huynh, Earl May, Erik Schaefer. A novel sox-based continuous and homogeneous assay for the discovery of inhibitors of inactive and active AKT [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1666.

Abstract 1552: Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation

Abstract hosphatase and tensin homolog deleted on chromosome ten (PTEN) serves as a powerful tumor suppressor, and has been found to be downregulated in human bladder cancer (BC) tissues. Despite this observation, the mechanisms contributing to PTEN’s downregulation have remained elusive. In this study, we discovered that mice exposed to N-butyl-N-(4-hydroxybu-tyl)nitrosamine (BBN), a specific bladder chemical carcinogen, exhibited primary basal muscle invasive BC (BMIBC) accompanied by a pronounced reduction in PTEN protein expression in vivo. Utilizing a lncRNA deep sequencing high-throughput platform, along with gain- and loss-of-function analyses, we identified small nucleolar RNA host gene 1 (SNHG1) as a critical lncRNA that might drive the formation of primary BMIBCs in BBN-treated mice. Cell culture results further demonstrated that BBN exposure significantly induced SNHG1 in normal human bladder urothelial cell UROtsa. Notably, the ectopic expression of SNHG1 alone was sufficient to induce malignant transformation in human urothelial cells, while SNHG1 knockdown effectively inhibited anchorage-independent growth of human BMIBCs. Our detailed investigation revealed that SNHG1 overexpression led to PTEN protein degradation through its direct interaction with HUR. This interaction reduced HUR binding to ubiquitin-specific peptidase 8 (USP8) mRNA, causing degradation of USP8 mRNA and a subsequent decrease in USP8 protein expression. The downregulation of USP8, in turn, increased PTEN poly-ubiquitination and degradation, culminating in cell malignant transformation and BMIBC anchorage-independent growth. In vivo studies confirmed the downregulation of PTEN and USP8, as well as their positive correlations in both BBN-treated mouse bladder urothelium and tumor tissues of bladder cancer in nude mice.Our findings, for the first time, demonstrate that overexpressed SNHG1 competes with USP8 for binding to HUR. This competition attenuates USP8 mRNA stability and protein expression, leading to PTEN protein degradation, consequently, this process drives urothelial cell malignant transformation and fosters BMIBC growth and primary BMIBC formation. Citation Format: Chuanshu Huang, Tengda Li, Honglei Jin. Tumorigenesis of basal muscle invasive bladder cancer was mediated by PTEN protein degradation resulting from SNHG1 upregulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1552.

Abstract 1903: Zenocutuzumab, a HER2xHER3 bispecific antibody, is effective in cancer models with high NRG1 expression

Abstract Neuregulin 1 (NRG1) is a ligand that binds to HER3, promotes HER2/HER3 dimerization and PI3K/AKT/mTOR signaling, and causes malignant transformation. Zenocutuzumab (Zeno, MCLA-128) is a humanized IgG1 bispecific antibody that docks on HER2, preventing heterodimerization with HER3, while also blocking NRG1 interaction with HER3, and potently inhibiting NRG1-induced HER2:HER3 proliferation and survival signaling of cancer cells. High NRG1 expression arising from autocrine signaling or gene amplification is associated with poor prognosis in certain cancers, and resistance to standard therapies. The clinical efficacy and safety of Zeno in patients with NRG1 fusion-driven cancer who were enrolled in the ongoing global multicenter eNRGy study and Early Access Program were recently presented. Treatment with Zeno led to durable responses across multiple different previously treated NRG1 fusion tumor types. Zeno utilizes the Merus Dock & Block® mechanism to inhibit HER2/HER3 dimerization and the NRG1/HER3 tumor-signaling pathway and is effective at high NRG1 concentrations. Here, we examined the efficacy of Zeno in preclinical models representing different tumor types expressing high NRG1 levels. Zeno treatment of the lung cancer cell line HCC95, which harbors an NRG1 gene amplification, effectively inhibited signaling pathways involved in the regulation of proliferation and survival, including the PI3K/AKT/mTOR pathway and inhibited cell proliferation. The anti-tumor efficacy of Zeno in vivo against a panel of 28 patient-derived xenograft (PDX) models representing different tumor types was examined. Zeno significantly inhibited tumor growth in seven high-NRG1-expressing PDX models. These results show that Zeno is effective in tumor cell killing in vitro and in vivo in high NRG1-expressing cancer models representing multiple different tumor types. Citation Format: Marie N. O'Connor, Ron C. Schackmann, Igor Odintsov, Szabolcs Fatrai, Arie B. Brinkman, Sidney Walker, Jeroen J. Lammerts van Bueren, Cecile A. Geuijen. Zenocutuzumab, a HER2xHER3 bispecific antibody, is effective in cancer models with high NRG1 expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1903.

Abstract 5982: Cannabinoid derived product is a potential novel therapeutic for papillary thyroid carcinoma

Abstract Papillary thyroid carcinoma (PTC) is the most common thyroid cancer that usually affects women ages 20-50, presenting as an asymptomatic neck mass. Total or partial thyroidectomy shows an excellent prognosis; however, investigation into non-invasive therapeutics with minimal adverse effects is ongoing. In addition to driver mutations such as BRAF, RAS, and RET-PTC, p53 mutations have also been identified. The loss of function of p53 is linked to cancer progression from PTC to poorly differentiated thyroid cancer and possibly anaplastic thyroid cancer. The disruption of the Wnt cell pathway is documented to be related to malignant cell transformation in thyroid cancer, leading to remarkable upregulation of c-myc, resulting in enhancement of tumor growth and drug resistance. Previous studies revealed that upregulation of BCL-2 occurs at later stages of tumorigenesis and is involved in chemotherapy resistance in some forms of cancer. In PTC, the downregulation of BCL-2 is linked to its favorable prognosis. Cannabinoid Derived Products (CDPs) have shown effectiveness in inhibiting different types of cancer, with research dating back to the 1970s. Ongoing in-vitro and in-vivo studies show that CDPs can effectively modulate tumor growth. However, the apoptotic properties of CDPs are largely dependent on the cancer type and drug dose/concentration. Our investigation focuses on CDPs and its potential anti-cancer effects by modulation of gene expression. We investigated its effects on gene expression of p53, c-Myc, and BCL-2 in K1 cell line which consists of PTC cells obtained from metastasis of well-differentiated PTC. K1 PTC cells (1 x106 cells/mL) were cultured with CDPs and incubated at 37°C under 5% CO2 for 24 and 48 hours. Cells were harvested, and cell viability was determined via trypan blue exclusion assay. Using qRT-PCR, we determined the effects of CDPs on the expression of TP53, c-Myc, and BCL-2. Results show that the CDPs decreased the viability (p< 0.001) of K1 PTC cells in a dose and time-dependent manner. Within 24 hours, the cannabinoid-containing product increased the gene expression of TP53 (p < 0.01) and decreased the gene expression of BCL-2 (p< 0.01) and c-Myc (p< 0.05) in K1 PTC cells. The results suggest that CDPs interact as a potential regulator in cancer with the upregulation of p53 and downregulation of BCL-2 and c-Myc. Further in-vitro and in-vivo studies are needed to understand the mechanism and therapeutic potential of cannabinoid-containing products in papillary thyroid cancer. Citation Format: Carolina Taico, Ibrahim Musa, Fariba Ardalani, Anish Maskey, Nan Yang, Joseph Breslin, Raj Tiwari, Jan Geliebter, Xiu Min Li. Cannabinoid derived product is a potential novel therapeutic for papillary thyroid carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 5982.