Epithelial-mesenchymal Transition Transcription Factors Research Articles

Exploring the impact of MiR-92a-3p on FOLFOX chemoresistance biomarker genes in colon cancer cell lines.

Introduction: One of the primary obstacles faced by individuals with advanced colorectal cancer (CRC) is the potential development of acquired chemoresistance as the disease advances. Studies have indicated a direct association between elevated levels of miR-92a-3p and the progression, metastasis, and chemoresistance observed in CRC. We proposed that miR-92a-3p impairs FOLFOX (fluorouracil/oxaliplatin) chemotherapy response by upregulating the expression of chemoresistance biomarker genes through the activation of β-catenin and epithelial-mesenchymal transition (EMT). These FOLFOX biomarker genes include the pyrimidine biosynthesis pathway genes dihydropyrimidine dehydrogenase (DPYD), thymidylate synthase (TYMS), methylenetetrahydrofolate reductase (MTHFR), and the genes encoding the DNA repair complexes subunits ERCC1 and ERCC2, and XRCC1. Methods: To assess this, we transfected SW480 and SW620 colon cancer cell lines with miR-92a-3p mimics and then quantified the expression of DPYD, TYMS, MTHFR, ERCC1, ERCC2, and XRCC1, the expression of EMT markers and transcription factors, and activation of β-catenin. Results and discussion: Our results reveal that miR-92a-3p does not affect the expression of DPYD, TYMS, MTHFR, and ERCC1. Furthermore, even though miR-92a-3p affects ERCC2, XRCC1, E-cadherin, and β-catenin mRNA levels, it has no influence on their protein expression. Conclusion: We found that miR-92a-3p does not upregulate the expression of proteins of DNA-repair pathways and other genes involved in FOLFOX chemotherapy resistance.

Integrative analysis reveals associations between oral microbiota dysbiosis and host genetic and epigenetic aberrations in oral cavity squamous cell carcinoma.

Dysbiosis of the human oral microbiota has been reported to be associated with oral cavity squamous cell carcinoma (OSCC) while the host-microbiota interactions with respect to the potential impact of pathogenic bacteria on host genomic and epigenomic abnormalities remain poorly studied. In this study, the mucosal bacterial community, host genome-wide transcriptome and DNA CpG methylation were simultaneously profiled in tumors and their adjacent normal tissues of OSCC patients. Significant enrichment in the relative abundance of seven bacteria species (Fusobacterium nucleatum, Treponema medium, Peptostreptococcus stomatis, Gemella morbillorum, Catonella morbi, Peptoanaerobacter yurli and Peptococcus simiae) were observed in OSCC tumor microenvironment. These tumor-enriched bacteria formed 254 positive correlations with 206 up-regulated host genes, mainly involving signaling pathways related to cell adhesion, migration and proliferation. Integrative analysis of bacteria-transcriptome and bacteria-methylation correlations identified at least 20 dysregulated host genes with inverted CpG methylation in their promoter regions associated with enrichment of bacterial pathogens, implying a potential of pathogenic bacteria to regulate gene expression, in part, through epigenetic alterations. An in vitro model further confirmed that Fusobacterium nucleatum might contribute to cellular invasion via crosstalk with E-cadherin/β-catenin signaling, TNFα/NF-κB pathway and extracellular matrix remodeling by up-regulating SNAI2 gene, a key transcription factor of epithelial-mesenchymal transition (EMT). Our work using multi-omics approaches explored complex host-microbiota interactions and provided important insights into genetic and functional basis in OSCC tumorigenesis, which may serve as a precursor for hypothesis-driven study to better understand the causational relationship of pathogenic bacteria in this deadly cancer.

Single-cell transcriptomics reveals the intra-tumoral heterogeneity and SQSTM1/P62 and Wnt/β-catenin mediated epithelial to mesenchymal transition and stemness of triple-negative breast cancer

Triple-negative breast cancer (TNBC) is characterized by the complex tumor microenvironment (TME) consisting of an abundance of mesenchymal stem cells (MSCs), which is known to facilitate epithelial-to-mesenchymal transition (EMT). The development of single-cell genomics is a powerful method for defining the intricate genetic landscapes of malignancies. In this study, we have employed single-cell RNA sequencing (scRNA-seq) to dissect the intra-tumoral heterogeneity and analyze the single-cell transcriptomic landscape to detect rare consequential cell subpopulations of significance. The scRNA-seq analysis of TNBC and Normal patient derived samples revealed that EMT markers and transcription factors were most upregulated in MSC population. Further, exploration of gene expression analysis among TNBC and Normal patient-derived MSCs ascertained the role of SQSTM1/P62 and Wnt/β-catenin in TNBC progression. Wnt/β-catenin and Wnt/PCP signaling pathways are prominent contributors of EMT, stemness, and cancer stem cell (CSC) properties of TNBC. SQSTM1/P62 cooperates with the components of the Wnt/PCP signaling pathway and is critically involved at the interface of autophagy and EMT.Moreover, siRNA targeting SQSTM1/P62 and inhibitor of Wnt/β-catenin (FH535) in conjunction was used to explore molecular modification of EMT and stemness markers. Although SQSTM1/P62 is not crucial for cell survival, cytotoxicity assay revealed synergistic interaction between the siRNA/inhibitor. Modulation of these important pathways helped in reduction of expression of genes and proteins contributing to CSC properties. Gene and protein expression analysis revealed the induction of EMT to MET. Moreover, co-treatment resulted in inactivation of non-canonical Wnt VANGL2-JNK signaling axis. The synergistic impact of inhibition of SQSTM1/P62 and Wnt/β-catenin signaling facilitates the development of a potential therapeutic regimen for TNBC.

Abstract LB049: Isoharpontigenin inhibits migration and invasion of lung cancer cells through MEG3/EGFR pathway

Abstract Lung cancer is the second most common cancer in both men and women in the United States. Even though treatments including chemotherapy, targeted therapy, and immunotherapy are available, lung cancer has been the leading cause of cancer deaths. The discovery and evaluation of new alternative medications targeting lung cancer are tremendously important for reducing lung cancer mortality. Phytochemicals are very desirable chemotherapeutic agents because of their greater safety profile. Isorhapontigenin (ISO), one of the oral bioavailable dietary stilbenes, can be found in various natural resources. Our result showed that ISO treatment suppressed the invasion and migration of human lung cancer cell lines A549, H23, and H1299 cells. Long non-coding RNA Maternally Expressed Gene 3 (MEG3), a tumor suppressor, was downregulated or lost in various primary human tumor tissues and cancer cell lines. The low expression of MEG3 is correlated with poor prognosis in non-small cell lung cancer (NSCLC). Our results showed that ISO treatment elevated MEG3 levels in these lung cancer cell lines. One of the major genetic causes of lung cancer is mutations in the epidermal growth factor receptor (EGFR) receptor tyrosine kinase, resulting in activation of EGFR which activates several signaling pathways involved in cell proliferation, drug sensitivity, and angiogenesis. Our results showed that ISO decreased the phosphorylation and protein levels of EGFR in A549 cells. Hypoxia-inducible factor-1α (HIF-1α), a transcription factor, regulates the activation of several genes involved in cell proliferation, angiogenesis, invasion, and metastasis. Our results showed that ISO decreased HIF-1α protein levels. Overexpression of MEG3 reduced p-EGFR and HIF-1α, indicating MEG3 negatively regulated EGFR and HIF-1α. Our data also showed that inhibition of EGFR by its tyrosine inhibitor decreased HIF-1α, suggesting that EGFR positively regulates HIF-1α. In cancer cells, Epithelial-Mesenchymal Transition(EMT) endows cells with increased invasiveness and tumor-initiating capacity, contributing to metastasis and resistance to therapeutics. Slug, one of the EMT transcription factors maintains cell plasticity during carcinogenesis. Our results showed that ISO treatment decreased Slugprotein levels in A549 and H23 cells. Transcription factor SOX2 regulates cancer cell proliferation, EMT, migration, invasion, metastasis, tumor initiation, cancer stem cell formation as well as resistance to apoptosis and therapy. Our results showed that ISO decreased SOX2 expression. Knockdown of MEG3 increased the expressions of Slug and SOX2, indicating that MEG3 negatively regulates Slug and SOX2. In conclusion, ISO elevated MEG3, inhibiting EGFR, HIF-1α, Slug, and SOX2, suppressing the migration and invasion of lung cancer cells. Citation Format: Sophia Shi, Zhuo Zhang, Jingxia Li, Huailu Tu, Max Costa. Isoharpontigenin inhibits migration and invasion of lung cancer cells through MEG3/EGFR pathway [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB049.

Dipeptidyl-peptidase 9 regulates the dynamics of tumorigenesis and metastasis in breast cancer

The cytosolic dipeptidyl-aminopeptidase 9 (DPP9) cleaves protein N-termini post-proline or -alanine. Our analysis of DPP9 mRNA expression from the TCGA ‘breast cancer’ data set revealed that low/intermediate DPP9 levels are associated with poor overall survival of breast cancer patients. To unravel the impact of DPP9 on breast cancer development and progression, the transgenic MMTV-PyMT mouse model of metastasizing breast cancer was used. In addition, tissue- and time-controlled genetic deletion of DPP9 by the Cre-loxP recombination system was done. Despite a delay of tumor onset, a higher number of lung metastases were measured in DPP9-deficient mice compared to controls. In human mammary epithelial cells with oncogenic RAS pathway activation, DPP9 deficiency delayed tumorigenic transformation and accelerated TGF-β1 induced epithelial-to-mesenchymal transition (EMT) of spheroids. For further analysis of the mechanism, primary breast tumor cells were isolated from the MMTV-PyMT model. DPP9 deficiency in these cells caused cancer cell migration and invasion accompanied by EMT. In absence of DPP9, the EMT transcription factor ZEB1 was stabilized due to insufficient degradation by the proteasome. In summary, low expression of DPP9 appears to decelerate mammary tumorigenesis but favors EMT and metastasis, which establishes DPP9 as a novel dynamic regulator of breast cancer initiation and progression.

Abstract 207: Tumor suppressive role of NKX2-1 in advanced thyroid cancer progression

Abstract NKX2-1 is a homeodomain transcription factor, known as a master regulator of thyroid development. NKX2-1 is also crucial for lung epithelium differentiation, and the involvement of NKX2-1 in lung carcinogenesis and cancer progression has been intensely investigated. However, the role of NKX2-1 in thyroid cancer progression remains elusive. The Cancer Genome Atlas (TCGA) dataset analysis demonstrated that papillary thyroid cancer (PTC) patients with low NKX2-1 mRNA expression had significantly poorer prognosis than those with a combination of intermediate and high mRNA expression of NKX2-1. Lentivirus-transduced tetracycline (Tet)-inducible system was used to achieve NKX2-1 overexpression in advanced follicular thyroid cancer (FTC) cell lines, FTC-238 and WRO, and an anaplastic thyroid cancer (ATC) cell line 8305C, in which NKX2-1 expression is barely/not detected. All these thyroid cancer cell lines showed significant suppression of cell proliferation with NKX2-1 overexpression. In addition, NKX2-1 overexpression inhibited migration of FTC-238 cells. The levels of mRNA and protein expression of mesenchymal markers, matrix metalloproteinase-2 (MMP-2) and fibronectin, were decreased by NKX2-1 overexpression in FTC-238 cells, suggesting a possibility that NKX2-1 partially inhibits epithelial-mesenchymal transition (EMT). SNAIL and SLUG are essential EMT transcription factors involved in metastasis in cancer progression. NKX2-1 mRNA expression was significantly lower in high SNAI1 (encoding SNAIL) expressing PTC in TCGA database. Indeed, suppression of SNAIL protein expression was found upon overexpression of NKX2-1 in FTC-238 cells which naturally express high level of SNAIL. These findings suggest that NKX2-1 may inhibit the migration of advanced thyroid cancer cells through SNAIL-induced EMT. Similarly, suppression of SLUG protein expression by overexpression of NKX2-1 was observed in WRO and 8305C cells which express high level of SLUG protein. Whether NKX2-1 overexpression inhibits migration and invasion of WRO and 8305C cells through SLUG-induced EMT is currently under examination. The Tet-inducible NKX2-1 expressing thyroid cancer cells will be used for in vivo evaluation of their metastatic ability using an immunocompromised mouse model. The findings so far suggest that NKX2-1 exerts a tumor suppressive activity in advanced thyroid cancers through suppression of cell proliferation, and cell migration presumably via suppression of EMT transcription factors. Citation Format: Yo-Taro Shirai, Shioko Kimura. Tumor suppressive role of NKX2-1 in advanced thyroid 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 207.

Abstract 4743: Targeting a novel TWIST1-Hexokinase II pathway to overcome MET TKI resistance in NSCLC

Abstract Non-small cell lung cancer (NSCLC) is the most common primary tumor to metastasize to the brain, with up to 40% of NSCLC patients developing brain metastases (BM). These BM portend a poor prognosis, even when extracranial disease is well-controlled. While targeted therapy and immunotherapy have improved lung cancer survival, there are no therapies specifically targeting NSCLC BM. Our lab identified a significant enrichment of MET amplification in lung adenocarcinoma (LUAD) BM (16%) compared to primary NSCLC (3%) and liver metastases (5%). MET, a receptor tyrosine kinase, and its ligand, hepatocyte growth factor (HGF), promote proliferation, epithelial-mesenchymal transition (EMT), angiogenesis, and metastasis. Although MET tyrosine kinase inhibitors (TKIs) are approved for use in METaltered NSCLC, half of patients with MET alterations fail to respond or inevitably acquire TKI resistance. We have found that MET pathway activation by MET alterations leads to increased expression of TWIST1, an EMT transcription factor required for tumorigenesis in MET-dependent NSCLC. Together, the HGF/MET/TWIST1 axis promotes cancer survival and metastasis. We found that MET amplified BM had distinct transcriptional signatures reflecting increased glycolysis. A similar shift toward glycolysis was observed in the MET amplified metastatic LUAD cell line (H1993) compared to the MET wild type primary LUAD line (H2073) derived from the same patient. Furthermore, LUAD cell lines with high MET expression demonstrated increased expression and activity of glycolytic enzymes, as well as increased susceptibility to glucose deprivation and glycolytic inhibitors (2DG, PFK158, AT-101, V-9302). Conversely, treatment of MET amplified cells with MET TKI, capmatinib, reduced glycolysis and oxidation phosphorylation to the levels observed in MET wild type LUAD lines. Activation of the MET pathway with HGF or TWIST1 overexpression specifically increased the mRNA and protein expression of the key glycolytic enzyme, Hexokinase II (HK2), compared to other glycolytic pathway proteins. Conversely, inhibition of the MET pathway with capmatinib or the TWIST1 inhibitor, harmine, decreased HK2 protein expression through a MYC-independent pathway. However, TWIST1 was required for MET-dependent transcriptional upregulation of HK2. Remarkably, in two novel MET altered models (cell line and patient derived xenograft) of acquired MET TKI resistance, TWIST1 and HK2 expression were increased at the time of resistance. Both models remained sensitive to pharmacologic inhibition of either TWIST1 or glycolysis at the time of acquired resistance to MET TKIs. These findings suggest that continued upregulation of the TWIST1-HK2 axis is required for acquired MET TKI resistance. In summary, these studies suggest a targetable, metabolic reprogramming in MET altered LUAD BM mediated through a novel TWIST1-HK2 pathway. Citation Format: Purva H. Rumde, Kasey R. Cargill, Vinod Kumar, Princey Devadassan, Jason Chen, Leviticus McGraw-Sapp, Xiaxuan Wu, Sanja Dacic, Riyue Bao, Bharathri Sivakama, Eric S. Goetzman, Sameer Agnihotri, Steven J. Mullett, Stacey G. Wendell, Laura P. Stabile, Timothy F. Burns. Targeting a novel TWIST1-Hexokinase II pathway to overcome MET TKI resistance in NSCLC [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 4743.

Abstract 2881: Comparing the effects of proton and photon therapy on promoting cancer aggressiveness in ovarian cancer and glioblastoma

Abstract Ovarian cancer is the 12th most common cancer among women in the United States and the 5th leading cause of cancer-related death for women. About 80% of the patients are diagnosed at stages III or IV, classified as High-Grade Serous Ovarian Cancer (HGSOC). HGSOC is highly aggressive, exhibiting an 80% recurrence rate within 24 months after cancer treatment. Brain and nervous system cancer ranks as the 10th leading cause of cancer-related death in the U.S., with Glioblastoma Multiforme (GBM) accounting for 47.7% of all brain cancer cases. GBM is the most aggressive primary brain cancer, with a 90% recurrence rate and a 4% 2-year survival rate. Patients with these cancers encounter limited treatment options, and the recurrence of cancer exacerbates these challenges. Therefore, a deeper understanding of the factors contributing to cancer treatment-induced aggressiveness is greatly needed. In our study, we first examined the treatment efficacy of proton and photon radiation by conducting apoptosis assays. Our findings demonstrate that proton radiation is significantly more effective at eliminating both HGSOC and GBM cells compared to photon radiation. Subsequently, we assessed the level of cancer aggressiveness in the surviving cells after radiation exposure by measuring stemness and epithelial-mesenchymal transition (EMT) levels. While proton radiation proved to be more effective in eliminating a greater number of cancer cells, we hypothesize that both proton and photon irradiation promote cancer aggressiveness in the surviving cells of HGSOC and GBM. To assess the stemness and EMT level of cancer cells following radiation, we integrated a SORE6-GFP reporter to identify the cancer stem cell population expressing SOX2/OCT4 and a 3’ UTR-ZEB1-GFP reporter to detect the cell population with mesenchymal traits. Cells transduced with the reporters were treated with 0, 1, 2, 4, and 8 Gy of 250 MeV proton and 6 MeV photon beams, and at 72 hours post-radiation, GFP levels were measured via flow cytometry. Our data demonstrated a dose-dependent increase in stemness and EMT levels in live cells after both types of radiation. Furthermore, cancer cells exposed to radiation were harvested at 72 hours and 240 hours post-radiation for RT-qPCR analysis. Our preliminary data indicate an upregulation of stemness genes including POU5F1 and SOX2, as well as EMT transcription factor genes ZEB1, SNAI1, and TWIST1 in response to both types of radiation in most cell lines. These findings indicate that both proton and photon radiation therapies promote cancer aggressiveness in the surviving cancer cells. Citation Format: Yeonkyu Jung, Ann Morcos, Aaron Keniston, Ashley Antonissen, Sharon Asariah, Antonella Bertucci, Marcelo Vazquez, Juli Unternaehrer. Comparing the effects of proton and photon therapy on promoting cancer aggressiveness in ovarian cancer and glioblastoma [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 2881.

Abstract 1438: Investigating the roles of EMT in small cell lung cancer tumorigenesis and chemoradiation response

Abstract In this study, we investigated the contributions of the epithelial-mesenchymal transition (EMT) program to small cell lung cancer (SCLC) tumorigenesis and chemoradiation (CRT) response. SCLC is a highly aggressive and deadly neuroendocrine malignancy. Two major factors that contribute to the high mortality of SCLC are (1) early metastasis and (2) rapid development of therapy resistance. Recent research suggests upregulation of EMT and the EMT transcription factor Twist1 correlated with accelerated tumor progression and CRT resistance in SCLC. Due to the lack of suitable animal models, the causal relationship between the EMT program and SCLC tumorigenesis and therapy response has not been rigorously investigated. To this end, we have generated a novel genetically engineered mouse model (GEMM) termed RPGT (Rb1Flox; Trp53Flox; ROSA26LSL-rtTA-IRES-EGFP; Twist1-TetO7-Luc). The RPGT GEMM enables the generation of autochthonous SCLC tumors after induction with Cre recombinase adenovirus. By withdrawing or providing doxycycline to mice, we can control Twist1 expression to activate or inactivate EMT in tumors. Upon characterizing mouse tumor samples with histological and molecular analyses, we observed that both control (no Twist1 overexpression) and Twist1-overexpressing RPGT mice developed neuroendocrine SCLC tumors. While SCLC-A was the predominant subtype in both cohorts, RPGT tumors exhibited more heterogeneity. Importantly, although no difference in tumorigenesis was observed, Twist1 overexpression dramatically increased the metastatic incidence in RPGT (87-100%) compared to control (25-50%) animals, indicating an important role of EMT in SCLC dissemination. Furthermore, transcriptomic profiling of primary tumors and matching metastases in RPGT mice revealed downregulation of Twist1 and EMT in metastases, suggesting that EMT suppression was necessary for metastatic outgrowth. To evaluate the impact of EMT activation on SCLC sensitivity to CRT, we performed in vitro viability assays on primary tumor cell lines established from RPGT tumors. We found that repressing Twist1 expression enhanced SCLC susceptibility to CRT. To validate these results in vivo, we treated RPGT mice with vs. without Twist1 overexpression with CRT. Consistent with our in vitro results, our in vivo data indicated that Twist1 overexpression promoted CRT resistance in SCLC tumors. Overall, our data suggest that the EMT program plays an important role in SCLC differentiation, metastasis, and resistance against chemo-radiotherapy. Citation Format: Triet Nguyen, Jinhee Chang, Kathleen Gabrielson, Amol Shetty, Yang Song, Audrey Lafargue, Shreya Jagtap, Danielle Council, Aaron Chan, Dipanwita Dutta Chowdhury, Muhammad Ajmal Khan, Nick Connis, Francesca Carrieri, Eddie Imada, Daniel Sforza, Eric Gardner, Christopher McFarland, Luigi Marchionni, Mohammad Rezaee, Christine Hann, Phuoc Tran. Investigating the roles of EMT in small cell lung cancer tumorigenesis and chemoradiation response [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 1438.

Abstract 200: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1

Abstract Background:Olive oil has long been considered a healthier edible oil, rich in 75% oleic acid (OA) as its main component. OA is a monounsaturated fatty acid, and recent studies have shown that it is no longer limited to protecting cardiovascular and cerebrovascular systems, but can also reduce the risk of cancer. However, there is limited research on the specific mechanism. After fatty acid is ingested into the body, through fatty acids β-oxidation produces acetyl-CoA, which is a donor of protein acetylation. EMT is an important process to regulate tumor metastasis, and Zeb1 is one of the important EMT transcription factors. Therefore, we explored whether OA could inhibit the progress of breast cancer by affecting the acetylation modification of Zeb1. Methods: Western blotting, CCK8 assay, and Transwell were used to test the impact of gradient doses of OA on breast cancer cells. Immunoprecipitation and Immunoprecipitation mass spectrum were used to determine the acetylation modification sites of Zeb1. Coimmunoprecipitation, IF, and pull-down were used to test and verify the acetylase and deacetylase of Zeb1. Knockdown endogenous ZEB1 and then reconstructed stable cell lines of Zeb1 wild-type (Zeb1K1108WT), acetylation activated (Zeb1K1108Q), and inactivated mutants (Zeb1K1108R) by lentivirus. Detection of Zeb1 acetylation in patient tissue samples and mouse models under OA treatment using Zeb1-specific acetylation-modified antibodies. Results: OA inhibits the proliferation and migration of breast cancer cells in a concentration gradient-dependent manner, and inhibits the expression of Zeb1, N Cadherin, and upregulates E Cadherin. Among numerous fatty acids, only OA can promote the acetylation of Zeb1 by adjusting the ratio of acetyl-CoA and NAD+/NADH. K1108 is a biologically functional acetylation site of Zeb1, Zeb1K1108R exerts the cancer promoting function of Zeb1, while Zeb1K1108Q does not. OA can promote acetylation of Zeb1K1108WT, but cannot promote acetylation of Zeb1K1108R. Conclusions: OA inhibits the development of breast cancer through K1108 acetylation of Zeb1. These results suggest that breast cancer may be ameliorated through dietary interventions. Citation Format: Min Guo, Yanjin Wang, Yi Shi, Shuang Yang. OA inhibits the development of breast cancer through K1108 acetylation of Zeb1 [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 200.

Abstract 2491: The Oxford Classic can identify HGSOC patients who may benefit from EMT-targeting therapies

Abstract Introduction: Despite development of novel targeted therapies such as PARP inhibitors and anti-angiogenic drugs, there is a clear lack of treatment options for High Grade Serous Ovarian Cancer (HGSOC) patients who are Homologous Recombination Repair proficient (50% of cases) and those with intrinsic resistance to these drugs. In this study we demonstrate the ability of the Oxford Classic (OxC)1,2, a non-genetic classifier, to identify HGSOC patients who may benefit from EMT targeting drugs. Methods: 139 HGSOC diagnostic tumor tissue (Brescia cohort) underwent RNA sequencing. Scottish cohort3 was used for external validation and TCGA, AOCS & OVCAD datasets were used for meta-analysis. Deconvolution of tumor RNAseq data, survival analyses, differential gene expression (DGE) analysis, gene pathway analyses in R and tumor immune profiling using CIBERSORT were performed. Results: Risk stratification of HGSOC using the Oxford Classic Patients with a higher OxC-EMT score had 3.6 times increased risk of death (95%CI: 1.6-8.0; p=2e-03) compared to patients with a lower OxC-EMT score by a multivariable cox regression analysis of Brescia cohort. By Kaplan-Meier survival analyses, a significant difference in overall survival in Brescia cohort (p=9e-06), Scottish cohort (p=2e-03) and a combined set of 1023 cases (p=1e-04), was observed between EMT-low risk patients (OxC-EMT score-0) and EMT-high risk patients (OxC-EMT score>0). Notably, 5-year median survival of EMT-low risk and EMT-high risk group was 50% and 13%, resp. (95%CI: 36.1%-69.3% vs 7.1%-23.5%) in Brescia cohort. Therapeutic options for OxC-EMT-high risk group DGE analysis of EMT-low patients and EMT-very high patients (OxC-EMT score>0.5) identified 404 differentially expressed genes common to the datasets. These included genes related to extracellular matrix organisation (VCAN, TGFβI), epithelial cell proliferation (RUNX2, FABP4, SERPINF1), cell chemotaxis (CCL19, DUSP1), angiogenic factors (VEGFC, CXCL12) and transmembrane kinase signalling pathways (TGFβ1/3, PDGFRα/β, IGFBP4/5/6, Wnt11). Of note, key EMT transcription factors, TWIST1/2, SNAI1/2, ZEB1/2, and stemness marker, ALDH1A3, were 2-7 times overexpressed in EMT-very high group. Furthermore, immune modulators, IL6 and IL10 were significantly upregulated and M2 macrophages were significantly more abundant in EMT-very high patients. Multiplex IHC is currently underway to confirm the abundance of TAMs and CD8-positive TRM in the two risk groups. Conclusions: 1) The Oxford Classic-based EMT is a robust prognostic biomarker of overall survival in HGSOC, that faithfully represents the complex circuitry of pathways which are a hallmark of Epithelial to Mesenchymal Transition. 2) OxC-EMT risk stratification can identify HGSOC patients who may benefit from EMT-targeting therapies. Reference: 1) Hu Z. Cancer Cell 2020 2) Hu Z. Clin Cancer Res 2021 3) Hollis R. Clin Cancer Res 2022 Citation Format: Lena Rai, Antonella Ravaggi, Eliana Bignotti, Robb Hollis, Joel Nulsen, Leticia Campo, Alistair Easton, Mara Artibani, Mike Churchman, Federico Ferrari, Christopher Yau, Charlie Gourley, Franco Odicino, Ahmed Ahmed. The Oxford Classic can identify HGSOC patients who may benefit from EMT-targeting 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 2491.

Targeting staphylococcal enterotoxin B binding to CD28 as a new strategy for dampening superantigen-mediated intestinal epithelial barrier dysfunctions.

Staphylococcus aureus is a gram-positive bacterium that may cause intestinal inflammation by secreting enterotoxins, which commonly cause food-poisoning and gastrointestinal injuries. Staphylococcal enterotoxin B (SEB) acts as a superantigen (SAg) by binding in a bivalent manner the T-cell receptor (TCR) and the costimulatory receptor CD28, thus stimulating T cells to produce large amounts of inflammatory cytokines, which may affect intestinal epithelial barrier integrity and functions. However, the role of T cell-mediated SEB inflammatory activity remains unknown. Here we show that inflammatory cytokines produced by T cells following SEB stimulation induce dysfunctions in Caco-2 intestinal epithelial cells by promoting actin cytoskeleton remodelling and epithelial cell-cell junction down-regulation. We also found that SEB-activated inflammatory T cells promote the up-regulation of epithelial-mesenchymal transition transcription factors (EMT-TFs) in a nuclear factor-κB (NF-κB)- and STAT3-dependent manner. Finally, by using a structure-based design approach, we identified a SEB mimetic peptide (pSEB116-132) that, by blocking the binding of SEB to CD28, dampens inflammatory-mediated dysregulation of intestinal epithelial barrier.

Lysine methyltransferase5C increases the proliferation and metastatic abilities of clear cell renal cell carcinoma via aerobic glycolysis.

Among all types of renal cancer, clear cell renal cell carcinoma (ccRCC) is the most common and lethal subtype and is associated with a high risk of metastasis and recurrence. Histone modifications regulate several biological processes that are fundamental to the development of cancer. Lysine methyltransferase5C (KMT5C; also known as SUV420H2) is an epigenetic modifier responsible for the trimethylation of H4K20, which drives critical cellular events, including genome integrity, cell growth and epithelial‑mesenchymal transition (EMT), in various types of cancer. However, the role of KMT5C in ccRCC remains unclear. As such, the expression and function of KMT5C in ccRCC were investigated in the present study. KMT5C expression was significantly increased in ccRCC tissues compared with normal tissues (P<0.0001), and it was closely associated with the overall survival rate of patients with ccRCC. By establishing ccRCC cell lines with KMT5C expression knockdown, the role of KMT5C in the maintenance of aerobic glycolysis in ccRCC cells via the regulation of several vital glycolytic genes was identified. Additionally, KMT5C promoted the proliferation and EMT of ccRCC cells by controlling crucial EMT transcriptional factors. Together, these data suggested that KMT5C may act as an oncoprotein, guide molecular diagnosis, and shed light on novel drug development and therapeutic strategies for patients with ccRCC.

INHBA is Enriched in HPV-negative Oropharyngeal Squamous Cell Carcinoma and Promotes Cancer Progression.

Patients with HPV-negative OPSCC have a poorer prognosis due to distinct molecular pathways. This study reveals significant transcriptomic differences between HPV-negative and HPV-positive OPSCC, identifying INHBA as a key upregulated gene in HPV-negative OPSCC's oncogenic pathways. INHBA is crucial in promoting EMT, cell proliferation, and an immunosuppressive tumor environment, suggesting its potential as a therapeutic target for HPV-negative OPSCC.

Plasticity-induced repression of Irf6 underlies acquired resistance to cancer immunotherapy in pancreatic ductal adenocarcinoma

Acquired resistance to immunotherapy remains a critical yet incompletely understood biological mechanism. Here, using a mouse model of pancreatic ductal adenocarcinoma (PDAC) to study tumor relapse following immunotherapy-induced responses, we find that resistance is reproducibly associated with an epithelial-to-mesenchymal transition (EMT), with EMT-transcription factors ZEB1 and SNAIL functioning as master genetic and epigenetic regulators of this effect. Acquired resistance in this model is not due to immunosuppression in the tumor immune microenvironment, disruptions in the antigen presentation machinery, or altered expression of immune checkpoints. Rather, resistance is due to a tumor cell-intrinsic defect in T-cell killing. Molecularly, EMT leads to the epigenetic and transcriptional silencing of interferon regulatory factor 6 (Irf6), rendering tumor cells less sensitive to the pro-apoptotic effects of TNF-α. These findings indicate that acquired resistance to immunotherapy may be mediated by programs distinct from those governing primary resistance, including plasticity programs that render tumor cells impervious to T-cell killing.

DOP88 Lipids drive myofibroblast activation and the epithelial-mesenchymal transition process in Crohn’s Disease

Abstract Background Fibrostenosis represents one of the major clinical complications of Crohn’s Disease (CD). However, the molecular mechanisms underlying intestinal fibrogenesis remain poorly understood and anti-fibrotic therapy has not yet been developed. Growing evidences supports that oxidative stress and the epithelial-mesenchymal transition (EMT) process contribute to the development and progression of fibrosis. Here, we assessed the role of lipids in fibrogenesis and whether mitochondria dysfunction can support fibrosis formation. Methods Spatial metabolomics analysis and adipophilin (ADFP) staining were performed on surgical specimens from fibrotic ileum and the surrounding region (healthy) derived from CD patients. Fibroblasts isolated from fibrotic and healthy ileum and human induced pluripotent stem cell-derived intestinal organoids (iHOs) were treated for 1-3 weeks with lipid mix (2%) and analyzed by RNA sequencing. Pathways significantly modulated were validated by RT-PCR, WB, FACS analysis, and proliferative, migratory and contraction assays, and mitochondrial functions by Seahorse analyzer. Results Spatial metabolomics revealed a significant accumulation of lipids characterized by very long-chain fatty acids in the fibrotic area compared to surrounding healthy regions, which was further confirmed by ADFP staining. RNA-seq analysis showed overlapping dysregulated pathways between healthy fibroblasts stimulated with lipids and fibrotic fibroblasts, in particular genes related to cell cycle, cytoskeletal reorganization, migration, contractility and cell metabolism (oxidative stress) which were further confirmed by functional assays. Among the genes related to oxidative stress, lipid stimulation significantly decreased NFE2L2 and promoted an increase in CPT1A, gene encoding for a fatty oxidation mediator. Moreover, lipid-stimulated fibroblasts showed a reduction in mitochondrial respiration, particularly basal and maximal respiration, and spare respiratory capacity by Seahorse analysis. On the other hand, long exposure of iHOs to lipids promoted the EMT process through the upregulation of TWIST, ZEB, VIM, and S100a4. Conclusion Lipid stimulation induced myofibroblast activation through oxidative stress and alteration of mitochondrial metabolism, and increased the expression of EMT transcription factors in intestinal epithelial cells (iHOs) that may support fibroblast-mediated pro-fibrotic activity. These data indicate that regulators of fatty acid oxidation involved in the fibrotic process may represent new potential targets for the treatment of fibrostenotic CD patients.

OP24 SPP1 in colitis-associated colon cancer

Abstract Background Patients with ulcerative colitis (UC) and Crohn’s disease (CD) face a lifelong risk of developing colitis-associated carcinoma (CAC). Current insights into CAC development originate from murine CAC models, while human CAC studies primarily focus on mutational analyses. Although the mutational landscape reveals distinct patterns and frequencies compared to colorectal cancer, it falls short in elucidating the inflammatory mechanisms of CAC development. Consequently, we adopted a multi-omics approach to unravel CAC carcinogenesis, utilizing human samples from patients with CD, CD-associated CAC (CD-CAC), UC, and UC-associated CAC (UC-CAC). Findings were further validated in vitro using human colon organoids. Methods A Nanostring Immunology v2 panel was employed on RNA (archival FFPE sections) from 40 patients suffering from either IBD or CAC, alongside inflammation-free healthy controls (n=10 per group). Our data revealed a robust upregulation of the SPP1 (Secreted Phosphoprotein 1) gene encoding osteopontin (OPN) in CAC patients. Prospectively, we extended our methodology to an unbiased imaging-based spatial RNA in situ sequencing (ISS) approach (477 genes, Xenium, 10X Genomics) using FFPE sections from CAC and UC patients (n=3 per group). This provided insights into the spatial expression of SPP1 and its target receptors at a subcellular resolution. Findings were validated using whole FFPE section confocal microscopy. In addition, in vitro models, including human UC organoids, were analyzed by bulk RNA-Seq, RT-qPCR, and downstream functional assays. Results Nanostring Immunology v2 gene expression data revealed upregulation of the SPP1 gene encoding OPN (Fig 1A) and EMT transcription factors FN1 and ZEB1 in CAC patients. Xenium RNA in situ sequencing (ISS) unveiled the spatial heterogeneity of SPP1 expression in CAC (Fig 1B). Unsupervised graph-based clustering identified an SPP1+CD68+ macrophage cluster exclusively in CAC (Fig 1C), validated through OPN/CD68 immunostainings (Fig 1D). In vitro OPN stimulation across multiple human and mice colon organoid models excluded OPN as the trigger of EMT. Interestingly, Xenium ISS and immunostainings revealed a mutually exclusive spatial location of SPP1/OPN+ macrophages and CD8+ T cells (Fig 1E, F and G). Conclusion SPP1 is significantly upregulated in CAC (RNA and protein), expressed by CD68+ macrophages. In vitro OPN stimulation demonstrated no direct effect on intestinal epithelial organoids. The mutually exclusive spatial locations of SPP1/OPN+ macrophages and CD8+ T cells suggests a crucial role of SPP1/OPN in modulating the immunosurveillance of CAC cells by CD8+ tumour lymphocytes.

P055 GPR43 and GPR84 play a crucial role in supporting perianal fistula formation and disease progression in Crohn’s Disease

Abstract Background Fistula complication represents one of the most disabling manifestations of Crohn’s Disease and a risk factor for more aggressive disease progression and mucinous adenocarcinoma . However, molecular mechanisms behind this transformation are completely unknown. Growing evidence supported epithelial-to-mesenchymal transition (EMT) as a critical process to replace impaired intestinal fibroblasts in repairing mucosal membrane damage. However, EMT drivers during fistula formation and progression are still not completely known. Here, we investigated whether G-protein coupled receptors serve as new drivers of EMT and fistula disease progression. Methods Surgical specimens (N=9) collected from perianal fistula and non-involved areas of CD patients were analyzed by bulk RNA-sequencing and Lipidomics analysis. Gene set enrichment analysis (GSEA) was used to detect the levels of differentially expressed pathways. GPR43 and GPR84 analysis was performed on perianal fistula; adenocarcinoma; and mucinous adenocarcinoma-associated (MA) CD fistula FFPE tissue section. Caco-2 cell line was stimulated for 24 h with agonists and antagonists of GPRs. Genes associated to EMT were evaluated by RT-PCR and WB. Results Gene sets related to the signatures of epithelial-to-mesenchymal transition, G-protein coupled receptors (GPRs), immune response, lipid oxidation were significantly enriched in the fistula compared to non-involved tissue. Among differentially GPRs expressed genes FFAR2 encoding for GPR43, sensor for Small Chain Fatty Acids (SCFAs), and GPR84 sensor for Medium Chain Fatty Acids (MCFAs), predominantly expressed in immune cells, reported to be upregulated in the context of acute inflammation. Upregulation of GPRs expression correlated positively with enzymes associated to lipid oxidation gen set including PLA2G2D, ALOX5, NR4A3, PLA2G7, ACOXL and negatively with their lipids substrates. Caco2 cells stimulated with SCFAs and MCFAs upregulated not only the expression of GPR43 and GPR84, but also of EMT-transcription factor Twist1 and PLA2G2D, all effects reverted in the presence of their antagonists. An increase expression of GPR43 and GPR84 in association with Twist1 was found in MA-CD tissue section. Conclusion Our results highlighted GPR43 and GPR84 as new potential factors of fistula formation that support the EMT process through increased fatty acid oxidation, which in turn fuels the activation of GPRs. However, the increase expression of both receptors in the fistula oncogenic disease progression suggests that strategies regulating lipid metabolism or targeting GPRs could pave the way for novel therapeutic approaches to prevent fistula complication in CD patients.

Resveratrol is an inhibitory polyphenol of epithelial-mesenchymal transition induced by Fusobacterium nucleatum

ObjectiveResveratrol is a natural phytoalexin that has anti-inflammatory properties, reverses doxorubicin resistance, and inhibits epithelial-mesenchymal transition (EMT) in many types of cancer cells. Fusobacterium nucleatum is reportedly enriched in oral squamous cell carcinoma (OSCC) tissues compared to adjacent normal tissues, sparking interest in the relationship between F. nucleatum and OSCC. Recently, F. nucleatum was shown to be associated with EMT in OSCC. In the present study, we aimed to investigate the effects of the natural plant compound resveratrol on F. nucleatum-induced EMT in OSCC. DesignF. nucleatum was co-cultured with OSCC cells, with a multiplicity of infection (MOI) of 300:1. Resveratrol was used at a concentration of 10 μM. Cell Counting Kit-8 and wound healing assays were performed to examine the viability and migratory ability of OSCC cells. Subsequently, real-time RT-PCR was performed to investigate the gene expression of EMT-related markers. Western blotting and immunofluorescence analyses were used to further analyze the expression of the epithelial marker E-cadherin and the EMT transcription factor SNAI1. ResultsCo-cultivation with F. nucleatum did not significantly enhance cell viability. The co-cultured cells displayed similarities to the positive control of EMT, exhibiting enhanced migration and expression changes in EMT-related markers. SNAI1 was significantly upregulated, whereas E-cadherin, was significantly downregulated. Notably, resveratrol inhibited F. nucleatum-induced cell migration, decreasing the expression of SNAI1. ConclusionsResveratrol inhibited F. nucleatum-induced EMT by downregulating SNAI1, which may provide a target for OSCC treatment.

A novel antagonist of the CCL5/CCR5 axis suppresses the tumor growth and metastasis of triple-negative breast cancer by CCR5-YAP1 regulation

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer (BC) with a high mortality rate, and few effective therapeutic strategies are available. CCL5/CCR5 is an appealing immunotherapeutic target for TNBC. However, its signaling mechanism is poorly understood and its direct antagonists have not been reported. Here, we developed a high-throughput screening (HTS) assay for discovering its antagonists. Verteporfin was identified as a more selective and potent antagonist than the known CCR5 antagonist maraviroc. Without photodynamic therapy, verteporfin demonstrated significant inhibition on TNBC tumor growth through immune regulation, remarkable suppression of lung metastasis by cell-intrinsic mechanism, and a significant extension of overall survival in vivo. Mechanistically, CCR5 was found to be essential for expression of the key hippo effector YAP1. It promoted YAP1 transcription via HIF-1α and exerted further control over the migration of CD8+ T, NK, and MDSC immune cells through chemokines CXCL16 and CXCL8 which were identified from RNA-seq. Moreover, the CCR5-YAP1 axis played a vital role in promoting metastasis by modulating β-catenin and core epithelial-mesenchymal transition transcription factors ZEB1 and ZEB2. It is noteworthy that the regulatory relationship between CCR5 and YAP1 was observed across various BC subtypes, TNBC patients, and showed potential relevance in fifteen additional cancer types. Overall, this study introduced an easy-to-use HTS assay that streamlines the discovery of CCL5/CCR5 axis antagonists. Verteporfin was identified as a specific molecular probe of this axis with great potentials as a therapeutic agent for treating sixteen malignant diseases characterized by heightened CCR5 and YAP1 levels.