Expression Of Epithelial-mesenchymal Transition Markers Research Articles

#1581 Anoctamin 3 inhibits gluconeogenesis and contributes to renal interstitial fibrosis through EZH2

Abstract Background and Aims Renal fibrosis is the common pathological pathway of various chronic kidney diseases progressing to the end stage of renal failure. Anoctamin 3 (ANO3) has been identified as a K-channel regulator and been extensively studied in the field of neurobiology. The role of ANO3 in kidney diseases is currently unknown. Method Mouse models of renal fibrosis were established by unilateral ureteral obstruction (UUO) operation or aristolochic acid I (AAI) injection. Human proximal tubular cell line (HK2) was used as an in vitro model. ANO3 was deleted in vitro by siRNA. Western blotting analysis was performed. Glucogenic metabolites were measured. Results We found that ANO3 is upregulated in mouse kidneys with unilateral ureteral obstruction (UUO) or aristolochic acid nephropathy (AAN), and tightly correlated with the progression of renal fibrosis and negatively correlated with expression of several rate-limiting enzymes of renal gluconeogenesis. Knockdown of ANO3 with siRNA increased the concentration of glucose and reduced the concentration of lactate in the supernatant of TGF-β stimulated renal proximal tubular (HK2) cells. In parallel, transfection of ANO3 siRNA significantly reduced the expression of epithelial-to-mesenchymal transition (EMT) and fibrotic markers in TGF-β stimulated HK2 cells. We further showed that ANO3 expression is positively correlated with the expression of a methyltransferase enhancer of zeste homologue 2 (EZH2) in UUO and AAN mouse kidneys by time. Transfection of ANO3 siRNA significantly reduced the expression of EZH2 in TGF-β stimulated HK2 cells. Overexpression of EZH2 by adenovirus reversed the pro-gluconeogenic and anti-fibrotic effect of ANO3 siRNA in TGF-β stimulated HK2 cells by measuring the concentration of glucose and lactate in supernatant and analyzing the expression of EMT or fibrotic markers. Conclusion In conclusion, ANO3 inhibits renal gluconeogenesis through EZH2 and contributes to renal fibrosis. ANO3 could be promising therapeutic target to inhibit renal fibrosis in chronic kidney disease patients.

Investigating the Genetic Diversity of Hepatitis Delta Virus in Hepatocellular Carcinoma (HCC): Impact on Viral Evolution and Oncogenesis in HCC.

Hepatitis delta virus (HDV), an RNA virus with two forms of the delta antigen (HDAg), relies on hepatitis B virus (HBV) for envelope proteins essential for hepatocyte entry. Hepatocellular carcinoma (HCC) ranks third in global cancer deaths, yet HDV's involvement remains uncertain. Among 300 HBV-associated HCC serum samples from Taiwan's National Health Research Institutes, 2.7% (8/300) tested anti-HDV positive, with 62.7% (5/8) of these also HDV RNA positive. Genotyping revealed HDV-2 in one sample, HDV-4 in two, and two samples showed mixed HDV-2/HDV-4 infection with RNA recombination. A mixed-genotype infection revealed novel mutations at the polyadenylation signal, coinciding with the ochre termination codon for the L-HDAg. To delve deeper into the possible oncogenic properties of HDV-2, the predominant genotype in Taiwan, which was previously thought to be less associated with severe disease outcomes, an HDV-2 cDNA clone was isolated from HCC for study. It demonstrated a replication level reaching up to 74% of that observed for a widely used HDV-1 strain in transfected cultured cells. Surprisingly, both forms of HDV-2 HDAg promoted cell migration and invasion, affecting the rearrangement of actin cytoskeleton and the expression of epithelial-mesenchymal transition markers. In summary, this study underscores the prevalence of HDV-2, HDV-4, and their mixed infections in HCC, highlighting the genetic diversity in HCC as well as the potential role of both forms of the HDAg in HCC oncogenesis.

Association between the expression of epithelial–mesenchymal transition (EMT)-related markers and oncologic outcomes of colorectal cancer

BackgroundEpithelial–mesenchymal transition (EMT) is a key step in the development of colorectal cancer (CRC) that confers metastatic capabilities to cancer cells. The present study aimed to assess the immunohistochemical (IHC) expression and impact of EMT markers, including E-cadherin, Vimentin, β-catenin, and SMAD4, on the oncologic outcomes of CRC.MethodsThis was a retrospective review of 118 CRC patients. Tissue slides were retrieved from the slide archive and five tissue microarray construction blocks were constructed. IHC for E-cadherin, Vimentin, β-catenin, and SMAD4 was done. The main outcome was the association between abnormal marker expression and overall survival (OS), and disease-free survival (DFS).ResultsAdenocarcinomas accounted for 71.2% of tumors, whereas 25.4% and 3.4% were mucinous and signet ring cell carcinomas. The rates of lymphovascular invasion and perineural invasion were 72.9% and 20.3%, respectively. There was a positive, significant correlation, and association between the four markers. Abnormal expression of E-cadherin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.06). Abnormal Vimentin expression was associated with a significantly higher rate of distant metastasis (p = 0.005) and significantly lower OS and DFS (p < 0.0001). Abnormal expression of β-catenin was associated with significantly lower OS (p < 0.0001) and similar DFS (p = 0.15). Abnormal expression of SMAD4 was associated with significantly lower OS and DFS (p < 0.0001). Abnormal expression of all four markers was associated with a higher disease recurrence, lower OS, and lower DFS.ConclusionAbnormal expression of each marker was associated with lower OS, whereas abnormal expression of Vimentin and SMAD4 only was associated with lower DFS.

Abstract P24: Elucidating the Mechanism of Action of Lenvatinib in Estrogen Receptor-Positive (ER+) Breast Cancer

Abstract Background: ER+ breast cancer is the most common subtype of breast cancer. Although most patients respond initially to endocrine therapy (ET), endocrine resistance inevitably develops, leading to disease progression. Lenvatinib, a multi-kinase inhibitor, demonstrated clinical benefit in the treatment of patients with advanced ER+ breast cancer who have progressed on ET in a phase Ib/II clinical trial from our group. Our study aims to elucidate the molecular mechanism of action of lenvatinib in ER+ breast cancer. Methods: A cell viability assay was performed to assess the sensitivity of four ER+ cell lines to lenvatinib. Western blot was used to elucidate its effect on downstream pathway signalling, and cell cycle arrest investigated through flow cytometry. A series of functional assays, including BrdU, colony formation and wound-healing assays assessed proliferative, clonogenic and migratory activity respectively. The effect of lenvatinib on epithelial-mesenchymal transition (EMT) was analysed using RT-qPCR, and compared with siRNA knockdown (KD) of Fgfr1 and Fgfr2. Results: ER+ cell lines demonstrated sensitivity to lenvatinib in the micromolar range. Western blot showed downregulation of FGFR1, FGFR2, pERK and pAKT expression post-treatment. Lenvatinib was found to induce a G1 phase arrest, suppressed cell proliferation in a dose-dependent manner, and diminished both the clonogenic ability and migratory activity of ER+ cells. Lenvatinib treatment reduced expression of Fgfr1, Fgfr2 and the mesenchymal markers N-cad and Fibronectin, while increasing the expression of the epithelial markers E-cad and Claudin-1, indicating potential inhibition of EMT. A similar change in EMT marker expression was observed in Fgfr1 KD but not Fgfr2 KD cells. Conclusion: Lenvatinib demonstrated potent anti-cancer activity and induction of G1 phase arrest, leading to decreased cell proliferation, reduction of clonogenic ability and cell migration. EMT inhibition was also observed, possibly through the FGFR1 signalling pathway. Citation Format: Natasha Gandasasmita, Gauri Vaidya, Arpita Datta, Charlie Marvalim, Joline Si Jing Lim, Soo Chin Lee. Elucidating the Mechanism of Action of Lenvatinib in Estrogen Receptor-Positive (ER+) Breast Cancer [abstract]. In: Proceedings of Frontiers in Cancer Science; 2023 Nov 6-8; Singapore. Philadelphia (PA): AACR; Cancer Res 2024;84(8_Suppl):Abstract nr P24.

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.

Pyrroloquinoline quinone ameliorates PM2.5-induced pulmonary fibrosis through targeting epithelial-mesenchymal transition.

Pulmonary fibrosis is a lung disorder affecting the lungs that involves the overexpressed extracellular matrix, scarring and stiffening of tissue. The repair of lung tissue after injury relies heavily on Type II alveolar epithelial cells (AEII), and repeated damage to these cells is a crucial factor in the development of pulmonary fibrosis. Studies have demonstrated that chronic exposure to PM2.5, a form of air pollution, leads to an increase in the incidence and severity of pulmonary fibrosis by stimulation of epithelial-mesenchymal transition (EMT) in lung epithelial cells. Pyrroloquinoline quinone (PQQ) is a bioactive compound found naturally that exhibits potent anti-inflammatory and anti-oxidative properties. The mechanism by which PQQ prevents pulmonary fibrosis caused by exposure to PM2.5 through EMT has not been thoroughly discussed until now. In the current study, we discovered that PQQ successfully prevented PM2.5-induced pulmonary fibrosis by targeting EMT. The results indicated that PQQ was able to inhibit the expression of type I collagen, a well-known fibrosis marker, in AEII cells subjected to long-term PM2.5 exposure. We also found the alterations of cellular structure and EMT marker expression in AEII cells with PM2.5 incubation, which were reduced by PQQ treatment. Furthermore, prolonged exposure to PM2.5 considerably reduced cell migratory ability, but PQQ treatment helped in reducing it. Invivo animal experiments indicated that PQQ could reduce EMT markers and enhance pulmonary function. Overall, these results imply that PQQ might be useful in clinical settings to prevent pulmonary fibrosis.

Abstract 2856: Multi-omics approaches for biomarker discovery and target therapy in pediatric germ cell tumors

Abstract Pediatric germ cell tumors (GCT) are rare and heterogeneous, presenting various histologies. There are no specific markers for diagnosing GCT, and 30% of patients are resistant to standard cisplatin-based chemotherapy, which can be related to epithelial-mesenchymal transition (EMT). Therefore, this study aims to elucidate markers for classifying GCTs, evaluate the molecular mechanisms related to drug resistance, and search for new therapeutic approaches. The expression of miRNAs was assessed for 42 GCT-pediatric patients through miRNA Panel - Nanostring technology. Whole Exome Sequencing (WES) was performed for 16 GCT-pediatric patients to assess somatic mutations. In silico analysis of epithelial-mesenchymal transition (EMT) markers was performed using the cBioPortal database. The expression of EMT markers was evaluated in vitro in parental and cisplatin-resistant models (NTERA-2R). Xenograft model-derived NTERA-2R was established and EMT markers were also assessed. We identified specific miRNA expression signatures for each histology, including 34 miRNAs for dysgerminomas, 13 for embryonal carcinomas, 25 for yolk sac tumors, and one for immature teratoma. We identified 26 miRNAs that were commonly expressed in malignant tumors, with six miRNAs (miR-302a-3p, miR-302b-3p, miR-371a-5p, miR-372-3p, miR-373-3p, miR-367-3p) showing significant overexpression. MiR-302b-3p had a significant association with all the evaluated clinical features. WES analysis showed that Single Base Substitution signature 39 was observed in 68.75% of samples and SBS22 in 12.5%. Copy number alterations were identified in 4, 7, 8, 10, 12, 21, and 22 chromosomes, with amplification of CDKN1B, KRAS, CCND2, ETV6, and KDM5A genes and deletions of KIT and PTEN genes. Somatic mutations in NYAP2, RHBDF2, MTOR, KIT, ATM, KRAS, and PIK3CA were frequent among the samples. KIT (Asp816Val, Ala829Pro) and KRAS (Gln61Leu) mutations were classified with potential clinical significance and were validated. In silico analysis showed that different histologies had distinct expression profiles for EMT markers. Patients with SNAILlowSLUGlow expression had higher PFS than those with SNAILhighSLUGhigh (p=0.006). The median PFS of patients with SLUGlow was 46.4 months, while SLUGhigh was 28.0 months (p=0.022). In vitro analysis using NTERA-2R showed overexpression of EMT markers. The same result was obtained in the xenograft model derived from NTERA-2R. Our study offers vital insights into pediatric GCTs' molecular landscape, using in silico, in vitro, in vivo analyses, and genetic assessments, highlighting three points: 1) The miRNA signatures for each histology may have robust diagnostic and prognostic potential, besides clinical implications as biomarkers. 2) KIT and KRAS genes are possible therapeutic targets of pediatric GCTs. 3) EMT is related to cisplatin resistance and SLUG is a potential molecular target. Citation Format: Ana Flavia Souza Peres, Ingridy Izabella Vieira Cardoso, Janaina Mello Soares Galvao, Ana Glenda Santarosa Vieira, Marcela Nunes Rosa, Isabela Cristiane Tosi, Daniel Antunes Moreno, Ana Carolina Laus, Andre van Helvoort Lengert, Silvia Aparecida Teixeira, Adriane Feijo Evangelista, Rui Manuel Reis, Luiz Fernando Lopes, Mariana Tomazini Pinto. Multi-omics approaches for biomarker discovery and target therapy in pediatric germ cell tumors [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 2856.

Abstract 5413: In vitro modeling of the migration ability of lung adenocarcinoma cell lines under hypoxic conditions

Abstract Hypoxia is a common condition in the tumor microenvironment that contributes to tumor cell migration, invasion, and metastasis, partly through inducing epithelial-mesenchymal transition (EMT). One of the key proteins in this process is hypoxia-inducible factor 1 (HIF-1), which regulates the expression of various genes as transcription factor and is vital for the cellular response in tissue hypoxia. Several studies have investigated the causation between hypoxic conditions and increased in vitro tumor cell motility and the role of potential regulatory signaling pathways. Understanding the precise molecular mechanisms underlying hypoxia-induced responses is crucial for better targeting tumor progression. However, establishing sound and predictive models is urgently needed to achieve this.In this study, we investigated the migration ability of four non-small cell lung cancer cell lines carrying different mutations of the growth factor pathway (H1975: EGFR T790M, PF901: BRAF V600E, PF139: KRAS G12C mutant, and H838: triple WT) under normoxic, hypoxic, and hypoxia-mimicking CoCl2-treated conditions. The motility of the cells was investigated by 48 h video microscopy (single cell random migration) and 72 h scratch assay. We analyzed the expression of crucial genes and proteins, including HIF-1α, as well as molecules associated with epithelial-mesenchymal transition (vimentin, n-cadherin, and e-cadherin), proliferation (PCNA), and apoptosis (PARP), using Western blot and qPCR techniques. Our work showed no change in cellular motility between any of the cell lines following treatment with CoCl2 compared to normoxic conditions. However, PF139 and PF901 cell lines showed a significant decrease in single-cell motility upon hypoxia. Interestingly, immunoblot analysis revealed stabilization of HIF-1α in response to both CoCl2 and hypoxia in the meantime. Additionally, we observed cell line-dependent changes in EMT marker expression upon CoCl2 treatment and hypoxia. Our work complements previous results published by our group and others on the tumor-promoting role of hypoxia, demonstrating that short-term exposure to hypoxia may act as an acute stressor for tumor cell lines. Our work suggests that the tumor progression-promoting effects are tissue-specific and should be investigated using long-term hypoxia models. Acknowledgments: This work was supported by the Hungarian Thematic Excellence Program (TKP2021-EGA-44) and the National Laboratories Program - National Laboratory for Tumor Biology (NLP-17). Sára Eszter Surguta is a grantee of the ITM-NKFIA funded Cooperative Doctoral Program (1018567). Citation Format: Sára Eszter Surguta, Marcell Baranyi, Laura Svajda, Ivan Ranđelović, Mihály Cserepes, József Tóvári. In vitro modeling of the migration ability of lung adenocarcinoma cell lines under hypoxic conditions [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 5413.

Abstract 6964: Regulation of TGF-β signaling via a novel TβRIII sheddase

Abstract In a normal cell, TGF-β signaling serves as a tumor suppressor by reducing proliferation and promoting apoptosis. Paradoxically, the function of TGF-β signaling reverses in a cancer cell and begins to promote oncogenic pathways such as proliferation, survival, evasion of the immune system, and epithelial to mesenchymal transition (EMT). This has made TGF-β signaling a very attractive therapeutic target for a wide variety of human carcinomas. As a result, many small molecule inhibitors of TGF-β signaling have been developed, but none have achieved FDA approval for use in human cancers due to the deleterious effects of inhibiting TGF-β responsiveness in normal cells. In effort to overcome this obstacle, we aim to restore the normal biological mechanisms that regulate TGF-β signaling. Specifically, the membrane bound co-receptor TβRIII can be proteolytically cleaved and shed from the membrane, resulting in an extracellular protein capable of binding and sequestering TGF-β ligand. This decoupling of ligand binding from the receptor allows TβRIII to suppress signaling. TβRIII shedding decreases TGF-β mediated oncogenic phenotypes such as migration and metastasis in multiple cancer types. However, this shedding is often lost in cancer. Therefore, restoration of TβRIII shedding could be a viable therapeutic approach for multiple cancer types. One potential mechanism for the loss of shedding is the negative regulation of the protease responsible for shedding (sheddase). However, the identity of the sheddase still remains unknown. Here, our goal is to identify the sheddase and uncover regulatory mechanisms that could be leveraged to restore TβRIII shedding in cancer. To achieve this goal, a library of protease CRISPR knockout viruses was screened to determine which proteases have an effect on shedding. The quantity of TβRIII shed into the cell culture media was measured via ELISA for each of these CRISPR knockout cell lines, and the candidates with the largest reduction of shedding were retained for further investigation. The list of candidates was further screened in silico via gene set enrichment analysis of human patient data against a TGF-β signaling gene set signature. Only the candidates demonstrating a negative correlation between sheddase candidate expression and TGF-β signaling activity were studied further. To further validate these candidate sheddases, knockdown and overexpression cell lines were created and characterized. Overexpression of the most promising candidate reduced TGF-β mediated phenotypes such as migration and invasion, while knockdown of this candidate increased the same phenotypes. Knockdown also increased expression of TGF-β and EMT markers. Importantly, these effects of sheddase knockdown were neutralized in the presence of the TGF-β inhibitor galunisertib or when the cells were rescued with exposure to purified soluble TβRIII, indicating the effects are mediated through TβRIII shedding. Citation Format: Benjamin M. Greulich, John Pawlak, John Post, Elena Karas, Gerard Blobe. Regulation of TGF-β signaling via a novel TβRIII sheddase [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 6964.

Abstract 992: The impact of tamoxifen on autophagic and epigenetic regulation in endometrial cancer

Abstract Background: Endometrial cancer, predominantly endometrioid adenocarcinoma, ranks as the fourth most common cancer in women globally, with an increasing incidence over the last two decades. Tamoxifen, well-known for its antiestrogenic characteristics in the treatment of breast cancer, paradoxically increases the risk of endometrial cancer. Understanding this dual role of tamoxifen is crucial for optimizing breast cancer therapy while mitigating endometrial cancer risk. This study aims to elucidate the molecular alterations induced by tamoxifen in endometrial thickening and its potential to induce cancer, particularly focusing on autophagy, epithelial-mesenchymal transition (EMT), and cancer stem-like cells (CSCs). Methods: In this study, female BALB/c mice were administered tamoxifen (20 mg/ml) orally for five consecutive days. We monitored changes in EMT markers, autophagy-related genes, and stem cell markers over 1 to 5 months. Furthermore, we investigated the epigenetic modulation of key genes involved in these processes. Results: Tamoxifen treatment led to altered expression of both epithelial and mesenchymal EMT markers, autophagy-related genes (p62, LC3B, Beclin-1, mTOR, ATG12, ATG16), and stem cell markers (Nanog, SOX2, ALDH1). Notably, we observed significant epigenetic changes, including increased methylation of E-cadherin and decreased methylation of Twist. Furthermore, we observed hypermethylation (a process often linked to the silencing of tumor-suppressing genes) in MGMT (Methylguanine methyltransferase), a DNA repair enzyme involved in chemoresistance, and DAPK (Death-associated protein kinase), a kinase associated with apoptosis, autophagy, and inflammation. We also observed hypermethylation in the CpG promoter regions of autophagy-related genes (Beclin-1 and LC3B) highlighting a potential mechanism for tamoxifen-induced tumorigenic changes. Conclusion: Our findings demonstrate tamoxifen's influence on cellular and molecular pathways, highlighting the complex interplay between drug treatment and cancer progression. The observed epigenetic changes provide insight into the mechanisms by which tamoxifen may contribute to endometrial cancer risk, suggesting potential targets for therapeutic intervention. Citation Format: Shilpa Thota, Rizwana Begum, Naveen Chintala, Abhishek Pandit, Biplov Sapkota, Joseph Francis. The impact of tamoxifen on autophagic and epigenetic regulation in endometrial 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 992.

Abstract 4294: The emerging role of deubiquitinase enzymes in lung cancer plasticity

Abstract Lung cancer is characterized by a high degree of genetic and molecular heterogeneity. Lineage plasticity has emerged as a source of intratumoral heterogeneity and drug resistance, resulting in poor prognosis and treatment failure. The molecular mechanisms driving lung cancer plasticity remain unclear. Ubiquitin-Specific Peptidase 13 (USP13), a deubiquitinating enzyme, is one of the most amplified genes in lung squamous cell carcinoma (LUSC). We developed a USP13 knock-in overexpressing mouse model in KrasLSL-G12D/+; Trp53fl/fl (KP) background (KPU mice). USP13 overexpression resulted in aggressive tumorigenesis and a shortened survival in Kras/Trp53-driven lung cancer. Notably, while KP mice developed lung adenocarcinoma (LUAD), KPU mice developed LUSC and LUAD. LUSC in KPU mice faithfully recapitulated the key pathohistological, molecular features, and cellular pathways of human LUSC. Bulk RNA-sequencing analysis showed that KPU tumors were heterogeneous and enriched in lineage reprogramming pathways including basal cell signaling, stem cell pluripotency, and epithelial-mesenchymal transition (EMT). Using cell-type-restricted adenoviral Cre to target cells expressing surfactant protein C (SPC) or club cell antigen 10 (CC10), we identified bronchiolar secretory club cells as the predominant cell origin of LUSC. USP13 altered the levels of lineage transcription factors such as TTF-1 and SOX2 in club cells during early tumorigenesis. Altered expression of these factors reinforced the fate of CC10+ club cells to squamous carcinoma development rather than adenocarcinoma. In addition, USP13 directly acted on the K48-linked ubiquitination of c-Myc and increased its protein stability, contributing to the elevation of squamous gene expression (SOX2, CK5, P40) in the primary mouse and advanced human lung cancer cells. These results suggest that USP13 promotes lineage plasticity in club cells during the early stage of cancer development and drives reprogramming into LUSC. We also found a potential functional association between USP13 and EMT pathway. Notably, irrespective of cell origin, USP13 overexpression enhanced EMT marker expression including N-cadherin, SNAI1, and ZEB1 in lung cancer cells, promoting cell migration and invasion. USP13 increased tumorigenic and metastatic abilities of lung cancer cells in 3D organoid culture and syngeneic mouse models. Collectively, our research highlights the pivotal significance of USP13 in unleashing lineage plasticity during lung cancer progression, suggesting the potential role of deubiquitinase enzymes in regulating lineage plasticity, which may lead to novel therapeutics for treating lung cancer. Citation Format: Juntae Kwon, Jinmin Zhang, Boram Mok, Samuel Allsup, Cecil Han. The emerging role of deubiquitinase enzymes in lung cancer plasticity [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 4294.

EMT Dynamics in Lymph Node Metastasis of Oral Squamous Cell Carcinoma.

Epithelial-mesenchymal transition (EMT) enables tumor cell invasion and metastasis. Many studies have demonstrated the critical role of EMT in lymph node metastasis in oral squamous cell carcinoma (OSCC). During EMT, epithelial cancer cells lose intercellular adhesion and apical-basal polarity and acquire mesenchymal properties such as motility and invasiveness. A significant feature of EMT is cadherin switching, involving the downregulation of E-cadherin and upregulation of N-cadherin. The TGF-β/SMAD pathway can also induce EMT. We aimed to evaluate EMT markers as predictors of lymph node metastasis in OSCC. We performed genetic profiling of 159 primary OSCCs from TCGA and analyzed the expression of EMT markers, including cadherin switch genes (CDH1, CDH2), and TGF-β/SMAD pathway genes. Samples were divided into advanced (stage III-IV) and early (stage I-II) stage groups. Differential expression analysis was performed, as well as an independent validation study containing fresh OSCC samples. TGF-β/SMAD pathway genes such as SMAD6 were upregulated in advanced stage tumors. N-cadherin and SNAIL2 were overexpressed in node-positive tumors. Keratins were downregulated in these groups. Our findings demonstrate that EMT marker expression correlates with lymph node metastasis in OSCC. Developing therapies targeting regulators such as N-cadherin may prevent metastasis and improve outcomes.

Abstract B008: Alternative PER2 (Period2) enhancer usage drives epithelial-mesenchymal transition (EMT) in epithelial ovarian cancer (OC)

Abstract B008: Alternative <i>PER2</i> (Period2) enhancer usage drives epithelial-mesenchymal transition (EMT) in epithelial ovarian cancer (OC)

PROM2 overexpression induces metastatic potential through epithelial-to-mesenchymal transition and ferroptosis resistance in human cancers.

Despite considerable therapeutic advances in the last 20 years, metastatic cancers remain a major cause of death. We previously identified prominin-2 (PROM2) as a biomarker predictive of distant metastases and decreased survival, thus providing a promising bio-target. In this translational study, we set out to decipher the biological roles of PROM2 during the metastatic process and resistance to cell death, in particular for metastatic melanoma. Methods and results: We demonstrated that PROM2 overexpression was closely linked to an increased metastatic potential through the increase of epithelial-to-mesenchymal transition (EMT) marker expression and ferroptosis resistance. This was also found in renal cell carcinoma and triple negative breast cancer patient-derived xenograft models. Using an oligonucleotide anti-sense anti-PROM2, we efficaciously decreased PROM2 expression and prevented metastases in melanoma xenografts. We also demonstrated that PROM2 was implicated in an aggravation loop, contributing to increase the metastatic burden both in murine metastatic models and in patients with metastatic melanoma. The metastatic burden is closely linked to PROM2 expression through the expression of EMT markers and ferroptosis cell death resistance in a deterioration loop. Our results open the way for further studies using PROM2 as a bio-target in resort situations in human metastatic melanoma and also in other cancer types.

TGFβ2 mediates oxidative stress–induced epithelial-to-mesenchymal transition of bladder smooth muscle

Bladder outlet obstruction (BOO) is the primary clinical manifestation of benign prostatic hyperplasia, the most common urinary system disease in elderly men, and leads to associated lower urinary tract symptoms. Although BOO is reportedly associated with increased systemic oxidative stress (OS), the underlying mechanism remains unclear. The elucidation of this mechanism is the primary aim of this study. A Sprague–Dawley rat model of BOO was constructed and used for urodynamic monitoring. The bladder tissue of rats was collected and subjected to real-time reverse transcription-quantitative polymerase chain reaction (RT-qPCR), histological examination, and immunohistochemical staining. Through bioinformatics prediction, we found that transforming growth factor β2 (TGFβ2) expression was upregulated in rats with BOO compared with normal bladder tissue. In vitro analyses using primary bladder smooth muscle cells (BSMCs) revealed that hydrogen peroxide (H2O2) induced TGFβ2 expression. Moreover, H2O2 induced epithelial-to-mesenchymal transition (EMT) by reducing E-cadherin, an endothelial marker and CK-18, a cytokeratin maker, and increasing mesenchymal markers, including N-cadherin, vimentin, and α-smooth muscle actin (α-SMA) levels. The downregulation of TGFβ2 expression in BSMCs using siRNA technology alleviated H2O2-induced changes in EMT marker expression. The findings of the study indicate that TGFβ2 plays a crucial role in BOO by participating in OS-induced EMT in BSMCs.

TGF-β2-induced alterations of m6A methylation in hTERT RPE-1 cells

N6-methyladenosine (m6A) is a major type of RNA modification implicated in various pathophysiological processes. Transforming growth factor β2 (TGF-β2) induces epithelial-mesenchymal transition (EMT) in retinal pigmental epithelial (RPE) cells and promotes the progression of proliferative vitreoretinopathy (PVR). However, the role of m6A methylation in the EMT of human telomerase reverse transcriptase (hTERT) retinal pigmental epithelium (RPE)-1 cells has not been clarified. Here, we extracted RNA from RPE cells subjected to 0 or 20 ng/mL TGF-β2 for 72 h and identified differentially methylated genes (DMGs) by m6A-Seq and differentially expressed genes (DEGs) by RNA-Seq. We selected the genes related to EMT by conjoint m6A-Seq/RNA-Seq analysis and verified them by qRT-PCR. We then confirmed the function of m6A methylation in the EMT of RPE cells by knocking down the methyltransferase METTL3 and the m6A reading protein YTHDF1. Sequencing yielded 5814 DMGs and 1607 DEGs. Conjoint analysis selected 467 genes altered at the m6A and RNA levels that are closely associated with the EMT-related TGF-β, AGE-RAGE, PI3K-Akt, P53, and Wnt signaling pathways. We also identified ten core EMT genes ACTG2, BMP6, CDH2, LOXL2, SNAIL1, SPARC, BMP4, EMP3, FOXM1, and MYC. Their RNA levels were evaluated by qRT-PCR and were consistent with the sequencing results. We observed that METTL3 knockdown enhanced RPE cell migration and significantly upregulated the EMT markers N-cadherin (encoded by CDH2), fibronectin (FN), Snail family transcription repressor (SLUG), and vimentin. However, YTHDF1 knockdown had the opposite effects and decreased both cell migration and the N-cadherin, FN, and SLUG expression levels. The present study clarified TGF-β2-induced m6A- and RNA-level differences in RPE cells, indicated that m6A methylation might regulate EMT marker expression, and showed that m6A could regulate TGF-β2-induced EMT.

The clustering status of detached gastric cancer cells inhibits anoikis-induced ferroptosis to promote metastatic colonization

Background and purposeFerroptosis is a form of regulated cell death characterized by iron-dependent lipid peroxidation. Its role in cancer metastasis remains unclear. In this study, we aimed to investigate the potential involvement of ferroptosis in gastric cancer (GC) metastasis.MethodsGC cells (AGS, MKN45, HGC27) were used to explore the role of ferroptosis in single and clustered cells with extracellular matrix (ECM) detachment in vitro. We overexpressed glutathione peroxidase 4 (GPX4) to inhibit ferroptosis and assessed the changes in cell proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT). Then tumor tissues from 54 GC patients with and without lymphatic metastasis were collected for immunohistochemical staining to investigate the expression of ferroptosis and EMT markers. Finally, Kaplan–Meier survival curves were used to investigate the relationship between overall survival and expression of GPX4 in 178 GC patients.ResultsDetached single cells had lower viability than adherent cells, but cell clustering improved their survival under matrix-detached conditions. Detached single cells exhibited an induction of iron-dependent reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, lipid peroxidation, upregulation of ACSL4, TFRC and HO-1, increased iron levels, and changes in mitochondrial morphology. Opposite effects were observed in detached clustered cells, including the upregulation of the ferroptosis suppressors GPX4 and SLC7A11. Overexpression of GPX4 inhibited ferroptosis and promoted GC cell proliferation, migration, invasion, and EMT. Immunohistochemical analysis of tumor tissues from GC patients indicated that lymphatic metastasis was associated with higher potential for ferroptosis inhibition and EMT induction. Finally, Kaplan–Meier survival curves demonstrated a significant decrease in overall survival among GC patients with high GPX4 expression.ConclusionsOur study provides the first evidence that inhibition of ferroptosis is a crucial mechanism promoting GC metastasis. GPX4 may be a valuable prognostic factor for GC patients. These findings suggest that targeting ferroptosis inhibition may be a promising strategy for GC patients with metastatic potential.Trial registration The ethical approval code of this study in Institutional Review Board of Peking Union Medical College Hospital is No: K1447.

MicroRNA-145-5p Regulates the Epithelial-Mesenchymal Transition in Nasal Polyps by Targeting Smad3.

The annual prevalence of chronic rhinosinusitis (CRS) is increasing, and the lack of effective treatments imposes a substantial burden on both patients and society. The formation of nasal polyps in patients with CRS is closely related to tissue remodeling, which is largely driven by the epithelial-mesenchymal transition (EMT). MicroRNA (miRNA) plays a pivotal role in the pathogenesis of numerous diseases through the miRNA-mRNA regulatory network; however, the specific mechanism of the miRNAs involved in the formation of nasal polyps remains unclear. The expression of EMT markers and Smad3 were detected using western blots, quantitative real-time polymerase chain reaction, and immunohistochemical and immunofluorescence staining. Differentially expressed genes in nasal polyps and normal tissues were screened through the Gene Expression Omnibus database. To predict the target genes of miR-145-5p, three different miRNA target prediction databases were used. The migratory ability of cells was evaluated using cell migration assay and wound healing assays. miR-145-5p was associated with the EMT process and was significantly downregulated in nasal polyp tissues. In vitro experiments revealed that the downregulation of miR-145-5p promoted EMT. Conversely, increasing miR-145-5p levels reversed the EMT induced by transforming growth factor-β1. Bioinformatics analysis suggested that miR-145-5p targets Smad3. Subsequent experiments confirmed that miR-145-5p inhibits Smad3 expression. Overall, miR-145-5p is a promising target to inhibit nasal polyp formation, and the findings of this study provide a theoretical basis for nanoparticle-mediated miR-145-5p delivery for the treatment of nasal polyps.

Miltirone suppresses ESCC cell viability and invasion by promoting E3 ligase mediated‐FZD2 ubiquitination and degradation

AbstractEsophageal squamous cell carcinoma (ESCC) is the most common subtype of esophageal cancer and lacks effective treatment. A growing number of studies have confirmed that Frizzled class receptor 2 (FZD2), a receptor for Wnts, regulates cancer metastasis in cancers. This study aims to reveal the anti‐metastatic activity of miltirone on ESCC cells and its mechanism on FZD2 in vitro. Cell‐counting‐kit‐8 (CCK‐8) was used to detect the effect of miltirone on cell growth in ESCC cells. The invasion of ESCC cells was detected by wound healing and transwell assay. Immunofluorescence staining was used to detect the expressions of epithelial‐mesenchymal transition (EMT) markers and the location of FZD2. Western blot and quantitative polymerase chain reaction (q‐PCR) were used to detect levels of target genes, and FZD2 ubiquitination was detected by the co‐immunoprecipitation method. The levels of roof plate‐specific spondins (RSPO1‐4) in cells were determined by ELISA, q‐PCR, and western blot assays. Miltirone exhibits its strongest cytotoxicity with IC50 values of 6.80 μM and 8.43 μM for K30 and K150 cells, respectively. Miltirone inhibited the cell viability and expression of EMT markers, affecting the invasion ability of ESCC, attenuated the Wnt2/FZD2 pathway, and down‐regulated the level of FZD2, which is regulated by the ubiquitination of E3 ubiquitin ligase. Furthermore, we found that miltirone could reduce the expression of RSPO1, and RSPO2, increasing E3 protein levels, and promoting FZD2 ubiquitination, leading to the ubiquitination and subsequent degradation of FZD2. Collectively, our results revealed that miltirone might be a promising drug for the treatment of ESCC, at least partly through regulation of the FZD2 ubiquitination.

Dual-Hit Strategy for Therapeutic Targeting of Pancreatic Cancer in Patient-Derived Xenograft Tumors.

Paracrine activation of pro-fibrotic hedgehog (HH) signaling in pancreatic ductal adenocarcinoma (PDAC) results in stromal amplification that compromises tumor drug delivery, efficacy, and patient survival. Interdiction of HH-mediated tumor-stroma crosstalk with smoothened (SMO) inhibitors (SHHi) "primes" PDAC patient-derived xenograft (PDX) tumors for increased drug delivery by transiently increasing vascular patency/permeability, and thereby macromolecule delivery. However, patient tumor isolates vary in their responsiveness, and responders show co-induction of epithelial-mesenchymal transition (EMT). We aimed to identify the signal derangements responsible for EMT induction and reverse them and devise approaches to stratify SHHi-responsive tumors noninvasively based on clinically-quantifiable parameters. Animals underwent diffusion-weighted magnetic resonance (DW-MR) imaging for measurement of intratumor diffusivity. In parallel, tissue-level deposition of nanoparticle probes was quantified as a marker of vascular permeability/perfusion. Transcriptomic and bioinformatic analysis was employed to investigate SHHi-induced gene reprogramming and identify key "nodes" responsible for EMT induction. Multiple patient tumor isolates responded to short-term SHH inhibitor exposure with increased vascular patency and permeability, with proportionate increases in tumor diffusivity. Nonresponding PDXs did not. SHHi-treated tumors showed elevated FGF drive and distinctly higher nuclear localization of fibroblast growth factor receptor (FGFR1) in EMT-polarized tumor cells. Pan-FGFR inhibitor NVP-BGJ398 (Infigratinib) reversed the SHHi-induced EMT marker expression and nuclear FGFR1 accumulation without compromising the enhanced permeability effect. This dual-hit strategy of SMO and FGFR inhibition provides a clinically-translatable approach to compromise the profound impermeability of PDAC tumors. Furthermore, clinical deployment of DW-MR imaging could fulfill the essential clinical-translational requirement for patient stratification.