Epithelial-mesenchymal Transition Transcription Factors Research Articles

The Role of Epithelial-to-Mesenchymal Transition Transcription Factors (EMT-TFs) in Acute Myeloid Leukemia Progression.

Acute myeloid leukemia (AML) is a diverse malignancy originating from myeloid progenitor cells, with significant genetic and clinical variability. Modern classification systems like those from the World Health Organization (WHO) and European LeukemiaNet use immunophenotyping, molecular genetics, and clinical features to categorize AML subtypes. This classification highlights crucial genetic markers such as FLT3, NPM1 mutations, and MLL-AF9 fusion, which are essential for prognosis and directing targeted therapies. The MLL-AF9 fusion protein is often linked with therapy-resistant AML, highlighting the risk of relapse due to standard chemotherapeutic regimes. In this sense, factors like the ZEB, SNAI, and TWIST gene families, known for their roles in epithelial-mesenchymal transition (EMT) and cancer metastasis, also regulate hematopoiesis and may serve as effective therapeutic targets in AML. These genes contribute to cell proliferation, differentiation, and extramedullary hematopoiesis, suggesting new possibilities for treatment. Advancing our understanding of the molecular mechanisms that promote AML, especially how the bone marrow microenvironment affects invasion and drug resistance, is crucial. This comprehensive insight into the molecular and environmental interactions in AML emphasizes the need for ongoing research and more effective treatments.

Restraint of melanoma progression by cells in the local skin environment.

Keratinocytes, the dominant cell type in the melanoma microenvironment during tumor initiation, exhibit diverse effects on melanoma progression. Using a zebrafish model of melanoma and human cell co-cultures, we observed that keratinocytes undergo an Epithelial-Mesenchymal Transition (EMT)-like transformation in the presence of melanoma, reminiscent of their behavior during wound healing. Surprisingly, overexpression of the EMT transcription factor Twist in keratinocytes led to improved overall survival in zebrafish melanoma models, despite no change in tumor initiation rates. This survival benefit was attributed to reduced melanoma invasion, as confirmed by human cell co-culture assays. Single-cell RNA-sequencing revealed a unique melanoma cell cluster in the Twist-overexpressing condition, exhibiting a more differentiated, less invasive phenotype. Further analysis nominated homotypic jam3b-jam3b and pgrn-sort1a interactions between Twist-overexpressing keratinocytes and melanoma cells as potential mediators of the invasive restraint. Our findings suggest that EMT in the tumor microenvironment (TME) may limit melanoma invasion through altered cell-cell interactions.

Mitochondrial Ca2+ controls pancreatic cancer growth and metastasis by regulating epithelial cell plasticity.

Endoplasmic reticulum to mitochondria Ca2+ transfer is important for cancer cell survival, but the role of mitochondrial Ca2+ uptake through the mitochondrial Ca2+ uniporter (MCU) in pancreatic adenocarcinoma (PDAC) is poorly understood. Here, we show that increased MCU expression is associated with malignancy and poorer outcomes in PDAC patients. In isogenic murine PDAC models, Mcu deletion (Mcu KO) ablated mitochondrial Ca2+ uptake, which reduced proliferation and inhibited self-renewal. Orthotopic implantation of MCU-null tumor cells reduced primary tumor growth and metastasis. Mcu deletion reduced the cellular plasticity of tumor cells by inhibiting epithelial-to-mesenchymal transition (EMT), which contributes to metastatic competency in PDAC. Mechanistically, the loss of mitochondrial Ca2+ uptake reduced expression of the key EMT transcription factor Snail and secretion of the EMT-inducing ligand TGFβ. Snail re-expression and TGFβ treatment rescued deficits in Mcu KO cells and restored their metastatic ability. Thus, MCU may present a therapeutic target in PDAC to limit cancer-cell-induced EMT and metastasis.

Alantolactone alleviates epithelial-mesenchymal transition by regulating the TGF-β/STAT3 signaling pathway in renal fibrosis

ObjectiveThe epithelial-to-mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) plays a crucial role in renal interstitial fibrosis and inflammation, which are key components of chronic kidney disease (CKD). Alantolactone, a selective inhibitor of signal transducer and activator of transcription 3 (STAT3), is used in Chinese herbal medicine. Despite its use, the effects of alnatolactone on EMT of RTECs has not been fully elucidated. MethodsIn this study, we investigated the potential of alantolactone to EMT in vivo and in vitro. Our experiments were performed using a unilateral ureteral obstruction (UUO) models and HK-2 cells, RTECs, treated with transforming growth factor (TGF-β). ResultsAlantolactone decreased tubular injury and reduced the expression of vimentin, a key EMT marker, while increasing E-cadherin expression in UUO kidneys. Similarly, in RTECs, alantolactone inhibited TGF-β-induced EMT and its markers. Furthermore, alantolactone attenuated UUO- and TGF-β-induced STAT3 phosphorylation both in vivo and in vitro, and inhibited the expression of TWIST, an EMT transcription factor, in both models. ConclusionAlantolactone improves EMT in RTECs by inhibiting STAT3 phosphorylation and Twist expression, suggesting its potential as a therapeutic agent for kidney fibrosis.

Zeb1 mediates EMT/plasticity-associated ferroptosis sensitivity in cancer cells by regulating lipogenic enzyme expression and phospholipid composition

Therapy resistance and metastasis, the most fatal steps in cancer, are often triggered by a (partial) activation of the epithelial–mesenchymal transition (EMT) programme. A mesenchymal phenotype predisposes to ferroptosis, a cell death pathway exerted by an iron and oxygen-radical-mediated peroxidation of phospholipids containing polyunsaturated fatty acids. We here show that various forms of EMT activation, including TGFβ stimulation and acquired therapy resistance, increase ferroptosis susceptibility in cancer cells, which depends on the EMT transcription factor Zeb1. We demonstrate that Zeb1 increases the ratio of phospholipids containing pro-ferroptotic polyunsaturated fatty acids over cyto-protective monounsaturated fatty acids by modulating the differential expression of the underlying crucial enzymes stearoyl-Co-A desaturase 1 (SCD), fatty acid synthase (FASN), fatty acid desaturase 2 (FADS2), elongation of very long-chain fatty acid 5 (ELOVL5) and long-chain acyl-CoA synthetase 4 (ACSL4). Pharmacological inhibition of selected lipogenic enzymes (SCD and FADS2) allows the manipulation of ferroptosis sensitivity preferentially in high-Zeb1-expressing cancer cells. Our data are of potential translational relevance and suggest a combination of ferroptosis activators and SCD inhibitors for the treatment of aggressive cancers expressing high Zeb1.

A Marine Collagen-Based 3D Scaffold for In Vitro Modeling of Human Prostate Cancer Niche and Anti-Cancer Therapeutic Discovery.

Recently, the need to develop a robust three-dimensional (3D) cell culture system that serves as a valuable in vitro tumor model has been emphasized. This system should closely mimic the tumor growth behaviors observed in vivo and replicate the key elements and characteristics of human tumors for the effective discovery and development of anti-tumor therapeutics. Therefore, in this study, we developed an effective 3D in vitro model of human prostate cancer (PC) using a marine collagen-based biomimetic 3D scaffold. The model displayed distinctive molecular profiles and cellular properties compared with those of the 2D PC cell culture. This was evidenced by (1) increased cell proliferation, migration, invasion, colony formation, and chemoresistance; (2) upregulated expression of crucial multidrug-resistance- and cancer-stemness-related genes; (3) heightened expression of key molecules associated with malignant progressions, such as epithelial-mesenchymal transition transcription factors, Notch, matrix metalloproteinases, and pluripotency biomarkers; (4) robust enrichment of prostate cancer stem cells (CSCs); and (5) enhanced expression of integrins. These results suggest that our 3D in vitro PC model has the potential to serve as a research platform for studying PC and prostate CSC biology, as well as for screening novel therapies targeting PC and prostate CSCs.

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.