ZEB1 Protein Research Articles

Micro-RNA-215 and -375 regulate thymidylate synthase protein expression in pleural mesothelioma and mediate epithelial to mesenchymal transition

The standard front-line treatment for pleural mesothelioma (PM) is pemetrexed-based chemotherapy, whose major target is thymidylate synthase (TS). In several cancer models, miR-215 and miR-375 have been shown to target TS, while information on these miRNAs in PM are still limited although suggest their role in epithelial to mesenchymal transition. Seventy-one consecutive PM tissues (4 biphasic, 7 sarcomatoid, and 60 epithelioid types) and 16 commercial and patient-derived PM cell lines were screened for TS, miR-215, and miR-375 expression. REN and 570B cells were selected for miR-215 and miR-375 transient transfections to test TS modulation. ZEB1 protein expression in tumor samples was also tested. Moreover, genetic profile was investigated by means of BAP1 and p53 immunohistochemistry. Expression of both miR-215 and miR-375 was significantly higher in epithelioid histotype. Furthermore, inverse correlation between TS protein and both miR-215 and miR-375 expression was found. Efficiently transfected REN and 570B cell lines overexpressing miR-215 and miR-375 showed decreased TS protein levels. Epithelioid PM with a mesenchymal component highlighted by reticulin stain showed significantly higher TS and ZEB1 protein and lower miRNA expression. A better survival was recorded for BAP1 lost/TS low cases. Our data indicate that miR-215 and miR-375 are involved in TS regulation as well as in epithelial-to-mesenchymal transition in PM.

Role of let7-g and miR-221 level as potential predictors for overall survival of hepatocellular carcinoma patients

Background and study aimsHepatocellular carcinoma (HCC) is one of the most common cancer types worldwide. A hallmark of epithelial-mesenchymal transition is the loss of epithelial E-cadherin, which is considered an epithelial differentiation marker. MicroRNAs serve vital roles in various biological processes in the cell via post-transcriptional gene regulation. Therefore, the present study aimed to investigate the involvement of certain miRNAs in the progression of HCC. Patients and methodsA reverse transcription-quantitative PCR assay was conducted to detect the expression levels of 20 EMT-related miRNAs in 36 fresh tissue biopsies from patients with primary HCC compared with healthy controls. Gene expression levels, as well as immunohistochemistry assays, were performed for E-cadherin, ZEB1 and ZEB2 proteins. The correlation between their expression levels and different clinicopathological factors was also assessed. ResultsA significant decrease of E-Cadherin and an increase in ZEB1 expression levels were identified in HCC groups compared with controls, while no significant changes for ZEB2 were found. The absence of E-cadherin membranous protein was observed in ∼48% of the cases examined. Moreover, ZEB1 protein was absent in 46% of E-cadherin positive cases. Upregulation of miR-182, miR-221 and miR-222 expression levels, and downregulation of let-7g, miR-9, miR-16, miR29c, miR122, miR-145, miR-148a, miR-193b, miR-194 and miR-215 expression levels were identified. A positive correlation between let7-g with E-Cadherin expression was reported. No significant association was identified between each of E-cadherin, ZEB1, ZEB2 or miRNAs examined with different clinicopathological features of the patients. Furthermore, the low expression of let7-g and high expression of miR-221 were associated with poorer survival. ConclusionCollectively, the present data suggested that let7-g functions as a tumor suppressor in the development of HCC via regulating E-Cadherin. Furthermore, both let7-g and miR-221 may be potential biomarkers for the outcomes of HCC patients.

ATP11A promotes EMT by regulating Numb PRRL in pancreatic cancer cells.

PurposeThe Numb protein plays a vital role in tumor development. The main aim of this study was to identify ATP11A, which is associated with the biological behavior of pancreatic cancer, and elucidate its relationship with Numb and the underlying mechanism behind this relationship.MethodsFirst, data retrieved from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEX) databases was used to investigate the expression of ATP11A mRNA and its relationship with Numb mRNA in pancreatic cancer. Western blot assays on 31 pairs of pancreatic cancer tissues and paracancerous tissues, and immunohistochemical assays on 81 pancreatic cancer specimens were performed in order to verify the expression of ATP11A in pancreatic cancer at the protein level. Next, ATP11A was overexpressed or knocked down to observe its effects on the invasion and migration ability of pancreatic cancer cells and the changes of downstream proteins. Rescue assays were conducted to determine the mechanism through which ATP11A affects Numb, ZEB1, Snail2 and other proteins. Furthermore, immunoprecipitation assays were performed to explore the interaction between ATP11A and Numb. Finally, pancreatic cancer cells were stimulated with TGFB1 and ATP11A expression was examined to explore whether the effect of ATP11A on EMT was TGFB dependent.ResultsAt the mRNA level, the expression of ATP11A in pancreatic cancer tissues was significantly higher than in normal pancreatic tissues (P < 0.001). ATP11A expression was also highly correlated with Numb expression (R = 0.676). At the protein level, ATP11A expression in pancreatic cancer tissues was significantly higher than that in paracancerous tissues (P = 0.0009), and high ATP11A expression was also correlated with a worse prognosis. Moreover, our results showed that ATP11A can promote the invasion and migration of pancreatic cancer cells. Additionally, ATP11A could positively regulate the expression of Numb PRRL, Snail2 and ZEB1 proteins. The rescue experiment results showed that the enhancement effect of ATP11A on ZEB1/Snail2 was suppressed by the specific knockdown of Numb PRRL. In addition, the immunoprecipitation results showed that ATP11A could specifically bind to Numb PRRL. The expression of ATP11A was also upregulated after TGFB stimulation, suggesting that the effect of ATP11A on EMT is TGFB dependent.ConclusionATP11A is significantly upregulated in pancreatic cancer tissues, where it promotes the invasion and migration ability of pancreatic cancer cells. It is also associated with adverse prognosis in pancreatic cancer. Furthermore, ATP11A affects the epithelial-to-mesenchymal transition (EMT) of pancreatic cancer by regulating the TGFB dependent Numb PRRL-ZEB1/Snail2 pathway.

406 Detection of zeb1 gene in women undergoing ivf treatment

Introduction and aims of the study: Infertility is a common problem worldwide and defined as the failure to achieve a clinical pregnancy after 12 months of regular, unprotected intercourse. ZEB1 protein is a zinc-finger E homeobox-binding transcription factor. ZEB1 is ivolved in epithelial to mesenchymal transition (EMT) acting as a repressor of E-cadherin and other epithelial markers through signaling pathways as TGF-β and Wnt/β-catenin. Overexpression of ZEB1 expression has been mainly correlated with endometriosis.

ZEB1 is Negatively Correlated with E-Cadherin in Prostatic Anomaly Tissue

Background: Prostatic anomalies are common in tumor or infection condition. The enlargement of prostate gland affects the epithelial cell polarity that involves epithelial-mesenchymal transition (EMT). Transition into mesenchymal is mediated by transcription factor ZEB1 and E-cadherin protein. Upregulation of ZEB1 and loss of E-Cadherin expression were associated to proliferation and metastasis of malignancy cells. This study aims to describe the correlation of ZEB1 and E-cadherin expression in prostatic anomaly.Materials and method: Samples were Formalin Fixed Paraffin Embedded (FFPE) block consist of 8 block Benign Prostatic Hyperplasia (BPH), 6 blocks High Grade Prostatic Intraepithelial Neoplasia (HGPIN) and 6 blocks Prostate Carcinoma (PCA). The blocks then sliced into 5 sections to be prepared for RNA extraction procedures. ZEB1 and E-Cadherin expression was analyzed by semi-quantitative procedures using PCR and electrophoresis. Correlation between ZEB1 and E-Cadherin espression was analyzed using Spearman’s rank correlation.Results: Relative expression of ZEB1 and E-cadherin mRNA in each group of prostatic anomaly were not significantly different (p&gt;0.05). ZEB1 and E-Cadherin mRNA expression showed a significant and moderate level of negative correlation (p&lt;0.05; 0.40 &lt; r &lt; 0.59). Increasing of ZEB1 mRNA expression will be followed by decreasing of E-Cadherin mRNA expression.Conclusion: ZEB1 negatively correlates with E-cadherin due to EMT process in prostatic anomaly. High expression of ZEB1 induced down-regulation of E-cadherin and vise versa. Various studies can be developed, especially the development of targeted therapy against ZEB1 to suppress the EMT process by increasing the expression of E-cadherin.Keywords: epithelial-mesenchymal transition (EMT), ZEB1, E-Cadherin, BPH, HGPIN, PCA

Exploring the mechanism of cordycepin combined with doxorubicin in treating glioblastoma based on network pharmacology and biological verification.

BackgroundGlioblastoma is the most common and fatal primary malignant tumor in the central nervous system, and the prognosis is poor. Currently, there are no effective treatments for glioblastoma. Cordycepin is a natural active substance with significant anticancer activity and doxorubicin is a broad-spectrum anticancer drug. Cordycepin administered with doxorubicin is a potential drug combination for the treatment of glioblastoma. However, the mechanism of action for this drug combination has not yet been elucidated.Aim of the studyTo explore the complex mechanism of cordycepin combined with doxorubicin against glioblastoma using network pharmacology and biological verification.Materials and methodsWe used an MTT assay, colony formation assay, and scratch healing to detect the growth, proliferation, and migration of LN-229, U251 and T98G cells. Putative targets and the potential mechanism of action for the drug combination in glioblastoma were obtained through online databases, network construction, and enrichment analyses. We verified the expression of EMT-related genes and identified important therapeutic targets by western blot.ResultsIn this study, the combination of doxorubicin and cordycepin was found to significantly inhibit cell proliferation and migration and can induce apoptosis. These effects are better together than with either drug alone. The drug combination inhibited EMT by upregulating the expression of E-cadherin protein and downregulating the expression of N-cadherin, ZEB1, and Twist1 proteins. There were 71 potential targets for the drug combination in glioblastoma, and Kyoto Encyclopedia of Genes and Genome analysis suggested that the anticancer process may be mediated by proteoglycans in cancer, the tumor necrosis factor signaling pathway, microRNA in cancer, pathways in cancer, and other pathways. To study the molecular mechanism of anticancer activity, we detected the expression of target proteins with downregulated expression of NFKB1, MAPK8, MYC, and MMP-9 proteins and upregulated expression of cleaved caspase 3 that promoted the apoptosis of LN-229 cells.ConclusionsThis study shows that the drug combination of doxorubicin and cordycepin effectively inhibits the growth and proliferation of LN-229 cells through multiple targets and multiple pathways, and the combination inhibits cell invasion and migration by regulating the EMT switch of tumor cells. Our findings provide new ideas about, and a theoretical basis for, the treatment of glioblastoma.

CDK4/6-USP51 axis regulates lung adenocarcinoma metastasis through ZEB1.

USP51 is a member of the deubiquitinase (DUB) family that participates in many pathophysiological processes. However, the aberrant expression and biological function of USP51 in cancer progression remain largely unclear. In this study, we demonstrated that USP51 is overexpressed in metastatic human lung adenocarcinoma and patients with high USP51 expression in their tumors have shorter overall survival than those with low expression of USP51. Moreover, we showed that USP51 promotes tumor metastasis and invasion through regulating ZEB1, which is a key transcriptional factor that induces the malignant progression of lung adenocarcinoma. In terms of molecular mechanism, USP51 is phosphorylated and activated by CDK4/6, thus resulting in the deubiquitination and stabilization of ZEB1 protein. Of note, we also confirmed that the expression of p-RB (an indicator of CDK4/6 activity), p-USP51 and ZEB1 are significantly positively correlated in human lung adenocarcinoma samples. In conclusion, these findings revealed that the CDK4/6-USP51-ZEB1 signaling pathway is a driver of lung adenocarcinoma metastasis, which could be a potential therapeutic strategy for the treatment of malignant tumors.

HER3 activation contributes toward the emergence of ALK inhibitor-tolerant cells in ALK-rearranged lung cancer with mesenchymal features

Anaplastic lymphoma kinase-tyrosine kinase inhibitors (ALK-TKIs) have shown dramatic efficacy in patients with ALK-rearranged lung cancer; however, complete response in these patients is rare. Here, we investigated the molecular mechanisms underlying the emergence and maintenance of drug-tolerant cells in ALK-rearranged lung cancer. Cell based-assays demonstrated that HER3 activation and mesenchymal-to-epithelial transition, mediated through ZEB1 proteins, help maintain cell survival and induce the emergence of ALK-TKI-tolerant cells. Compared with ALK-TKIs alone, cotreatment with pan-HER inhibitor afatinib and ALK-TKIs prevented tumor regrowth, leading to the eradication of tumors in ALK-rearranged tumors with mesenchymal features. Moreover, pre-treatment vimentin expression in clinical specimens obtained from patients with ALK-rearranged lung cancer was associated with poor ALK-TKI treatment outcomes. These results demonstrated that HER3 activation plays a pivotal role in the emergence of ALK-TKI-tolerant cells. Furthermore, the inhibition of HER3 signals combined with ALK-TKIs dramatically improves treatment outcomes for ALK-rearranged lung cancer with mesenchymal features.

Role of the Immunohistochemical ZEB1 Expression in Uterine Mesenchymal Neoplasms.

The distinction of mesenchymal tumors of the uterus is a frequent diagnostic challenge in gynecologic pathology. Especially, distinguishing low-grade endometrial stromal sarcoma (ESS) from leiomyoma or distinguishing low-grade ESS from high-grade ESS can be difficult. Epithelial-mesenchymal transition (EMT) is a physiological and pathological process in which epithelial cells lose their morphological features, become elongated and acquire mesenchymal traits. The signaling pathway of Zinc finger E-box binding homeobox 1 (ZEB1) is one of the most significant pathways involved in the EMT process and it has a crucial role in cancer progression, metastasis, and therapy resistance. We studied a series of 69 uterine mesenchymal neoplasms including 18 endometrial stromal sarcomas (10 cases of low grade and 8 cases of high grade endometrial stromal sarcomas), 26 leiomyosarcomas (8 cases of grade 1 and 19 cases of grade 2-3 leiomyosarcomas), 15 leiomyomas, and 10 rhabdomyosarcomas, using an antibody ZEB1. We graded the leiomyosarcomas depending on the FNCLCC grading system. It was observed that leiomyosarcoma was more intensely stained with ZEB1 than leiomyoma (P < 0.001) and high-grade ESS was significantly more intensely stained with ZEB1 protein than low-grade ESS (P < 0.004). It also was observed that high-grade leiomyosarcoma was significantly more intensely stained with ZEB1 protein than low-grade leiomyosarcoma (P < 0.000). Our data suggest that Zeb1 can be used to differentiate high-grade sarcomas from their low-grade counterparts as well as benign and malignant smooth muscle tumors of the uterus.

Micro ribonucleic acid-448 regulates zinc finger e-box binding homeobox 1 to inhibit the growth of breast cancer cells and increase their sensitivity to chemotherapy

ObjectiveThis study aimed to investigate the effect of Zinc Finger E-box Binding Homeobox 1 (ZEB1) regulation by Micro Ribonucleic acid (miR)-448 on Breast Cancer (BC) cells and their sensitivity to chemotherapy. MethodsmiR-448 and ZEB1 mRNA levels in BC and normal tissues were detected by qPCR, and ZEB1 protein was detected by Western Blotting (WB). The correlation between miR-448 and tumor metastasis, clinical staging, and ZEB1 expression was analyzed. MCF-7 cells were transfected or co-transfected with the miR-448 mimic, oe-ZEB1, or their negative controls. Changes in miR-448 and ZEB1 expression were detected by qPCR and WB. Cell proliferation was determined by CCK-8 assays, invasion changes were analyzed by Transwell assays, and apoptosis was detected by flow cytometry. ResultsmiR-448 expression in BC tissues was lower than that in normal tissues, while ZEB1 expression was increased in the former. ZEB1 expression was lower in BC patients with lymph node metastasis than in those without. In patients with clinical stage I–III BC, miR-448 expression decreased with an increase in tumor stage, which was negatively correlated with ZEB1 expression. Upregulation of miR-448 expression can suppress MCF-7 cell proliferation and invasion and promote apoptosis. Upregulation of ZEB1 expression in cells overexpressing miR-448 can partially reverse the inhibition of BC cell growth induced by miR-448. miR-448 can enhance the sensitivity of cells toward paclitaxel and 5-fluorouracil. ConclusionsmiR-448 suppresses cell proliferation and invasion and promotes apoptosis by targeting ZEB1. Moreover, it can increase the sensitivity of cells toward paclitaxel and 5-fluorouracil.

SENP1 promotes triple-negative breast cancer invasion and metastasis via enhancing CSN5 transcription mediated by GATA1 deSUMOylation.

TNBC is characterized by high incidence of visceral metastasis and lacks effective clinical targets. This study aims to delineate the molecular mechanisms of SENP1 in TNBC invasion and metastasis. By using IHC to test the SENP1 expression in TNBC tissues, we analyzed the relationship between SENP1 expression and TNBC prognosis. We showed that SENP1 expression was higher in TNBC tumor tissues and related to TNBC prognosis, supporting SENP1 as an independent risk factor. High expression of SENP1 was significantly associated with histologic grade and tumor lymph node invasion. Intriguingly, the expression levels of SENP1 in TNBC tumors were significantly correlated with that of CSN5, GATA1 and ZEB1. Importantly, SENP1 promoted TNBC cell migration and invasion by regulating ZEB1 deubiquitination and expression through CSN5. Further studies showed that deSUMOylation at lysine residue K137 of GATA1 enhanced the binding of GATA1 to the CSN5 promoter and transactivated CSN5 expression. In addition, we showed that ZEB1 is deubiquitinated at lysine residue K1108. Our in vivo studies also indicated that reduction in SENP1 expression upregulated GATA1 SUMOylation, and thus resulted in decreased expression of CSN5 and ZEB1 in the tumor microenvironment, which decelerated TNBC progression and metastasis. SENP1 promoted CSN5-mediated ZEB1 protein degradation via deSUMOylation of GATA1, and thus influenced TNBC progression. These findings suggest that SENP1 could be utilized as a potential target for blockade of TNBC development and thus provide a totally new approach for TNBC treatment.

Coordinate control of basal epithelial cell fate and stem cell maintenance by core EMT transcription factor Zeb1.

Maintenance of undifferentiated, long-lived, and often quiescent stem cells in the basal compartment is important for homeostasis and regeneration of multiple epithelial tissues, but the molecular mechanisms that coordinately control basal cell fate and stem cell quiescence are elusive. Here, we report an epithelium-intrinsic requirement for Zeb1, a core transcriptional inducer of epithelial-to-mesenchymal transition, for mammary epithelial ductal side branching and for basal cell regenerative capacity. Our findings uncover an evolutionarily conserved role of Zeb1 in promoting basal cell fate over luminal differentiation. We show that Zeb1 loss results in increased basal cell proliferation at the expense of quiescence and self-renewal. Moreover, Zeb1 cooperates with YAP to activate Axin2 expression, and inhibition of Wnt signaling partially restores stem cell function to Zeb1-deficient basal cells. Thus, Zeb1 is a transcriptional regulator that maintains both basal cell fate and stem cell quiescence, and it functions in part through suppressing Wnt signaling.

Role of pre-metastatic niche in organ specificity of breast cancer metastasis. Influence on metastatic potential as a basis for CDK4/6-inhibition efficacy in early therapy of disseminated hormone-receptor-positive disease

Influencing the pre-metastatic niche is a very perspective cancer treatment strategy in order of preventing metastases formation. It was found that bone marrow progenitor cells and tumor cells secreting biological compounds are key components in the formation of the pre-metastatic niche. Myeloid suppressor cells (MSCs) are the main type of bone marrow cells in pre-metastatic niches. At the same time, tumor-associated chronic inflammation induces the expression of proinflammatory cytokines triggering myeloid cells differentiation into myeloid suppressor cells. When circulating tumor cells enter the circulatory channel, their interaction with immune cells is observed, which additionally influences the pre-metastatic site preparation. Studies have shown that the entire spectrum of immune cells is capable of influencing the metastasis formation by circulating tumor cells. The epithelialmesenchymal transition with the tumor cell transporting form appearence was found to be related to the function of the ZEB1 protein. Its activity is regulated by numerous signaling mechanisms at the transcriptional level, including TGFβ, Wnt and Notch. This initiates epithelial-mesenchymal transition of breast cancer cells. Zhang Z.et al. proved that CDK4/6 blocking leads ZEB1 protein stability decreasing, preventing metastasis in breast cancer in vitro and in vivo. Moreover, USP51 deubiquitinase has been identified as a target of cyclin-dependent 4/6 kinases. At the molecular level, CDK4/6 phosphorylate and activates USP51, which then influences ZEB1 deubiquitination and stabilization. A positive correlation was demonstrated between the expression of p-RB (an indicator of CDK4/6 activity), p-USP51 and ZEB1 in breast cancer samples. Thus, the CDK4/6-USP51-ZEB1 axis may play a key role in the metastasis of breast cancer. In breast cancer cells, inhibition of CDK4/6 was shown to increase the expression of E-cadherin but decrease the expression of mesenchymal markers, reducing the migratory ability and invasiveness of breast cancer cell lines. This biological effect may also explain the clinical efficacy of the CDK4/6 inhibitor Abemaciclib in early-line therapy of metastatic breast cancer as well as in adjuvant combination hormone therapy for the prevention of metastatic lesions in patients at high risk of recurrence and progression in the MONARCH E study. Besides, there were no response predictors evaluated in trials investigating CDK4/6 in breast cancer treatment and it is unknown if there any differences in treatment response according to the metastatic site. The clinical cases demonstrate abemaciclib clinical efficacy in metastatic breast cancer treatment regardless of metastatic site.

ZEB1 represses biogenesis of circ-DOCK5 to facilitate metastasis in esophageal squamous cell carcinoma via a positive feedback loop with TGF-β

ZEB1 is an important transcription factor that plays a critical role in TGF-β-induced epithelial-mesenchymal transition (EMT) and tumor metastasis. However, the mechanisms by which ZEB1 regulates metastasis in esophageal squamous cell carcinoma (ESCC) remain largely unknown. Here, we identified a novel circular RNA, circ-DOCK5, the biogenesis of which is directly regulated by ZEB1 and ZEB1-repressed RNA-binding protein eIF4A3. Tissue microarray analysis identified circ-DOCK5 to be downregulated in ESCC tissues, and its downregulation correlated with poor prognosis. Moreover, circ-DOCK5 increased the stability of miR-627-3p by functioning as a "reservoir" for miR-627-3p to partially reverse the ZEB1-enhanced migration and invasion in ESCC. MiR-627-3p inhibited the expression of TGFB2 and the secretion of TGF-β, which further resulted in downregulation of ZEB1 and suppression of TGF-β-induced EMT. In vivo experiments showed that ZEB1 promoted metastasis in ESCC by regulating expression of circ-DOCK5. Therefore, the present study revealed that ZEB1-mediated downregulation of circ-DOCK5 facilitates metastasis in ESCC by forming a positive feedback loop with TGF-β by altering the miR-627-3p/TGFB2 signaling. Targeting this signaling pathway may help suppress progression in ESCC.

ZEB2 regulates endocrine therapy sensitivity and metastasis in luminal a breast cancer cells through a non-canonical mechanism.

The transcription factors ZEB1 and ZEB2 mediate epithelial-to-mesenchymal transition (EMT) and metastatic progression in numerous malignancies including breast cancer. ZEB1 and ZEB2 drive EMT through transcriptional repression of cell-cell junction proteins and members of the tumor suppressive miR200 family. However, in estrogen receptor positive (ER +) breast cancer, the role of ZEB2 as an independent driver of metastasis has not been fully investigated. In the current study, we induced exogenous expression of ZEB2 in ER + MCF-7 and ZR-75-1 breast cancer cell lines and examined EMT gene expression and metastasis using dose-response qRT-PCR, transwell migration assays, proliferation assays with immunofluorescence of Ki-67 staining. We used RNA sequencing to identify pathways and genes affected by ZEB2 overexpression. Finally, we treated ZEB2-overexpressing cells with 17β-estradiol (E2) or ICI 182,780 to evaluate how ZEB2 affects estrogen response. Contrary to expectation, we found that ZEB2 did not increase canonical epithelial nor decrease mesenchymal gene expressions. Furthermore, ZEB2 overexpression did not promote a mesenchymal cell morphology. However, ZEB1 and ZEB2 protein expression induced significant migration of MCF-7 and ZR-75-1 breast cancer cells in vitro and MCF-7 xenograft metastasis in vivo. Transcriptomic (RNA sequencing) pathway analysis revealed alterations in estrogen signaling regulators and pathways, suggesting a role for ZEB2 in endocrine sensitivity in luminal A breast cancer. Expression of ZEB2 was negatively correlated with estrogen receptor complex genes in luminal A patient tumors. Furthermore, treatment with 17β-estradiol (E2) or the estrogen receptor antagonist ICI 182,780 had no effect on growth of ZEB2-overexpressing cells. ZEB2 is a multi-functional regulator of drug sensitivity, cell migration, and metastasis in ER + breast cancer and functions through non-canonical mechanisms.

Abstract LB095: A domain-specific antibody to NRP2 down-regulated epithelial-mesenchymal transition genes and enhanced efficacy of standard-of-care therapeutics for aggressive breast cancer

Abstract INTRODUCTION: A growing body of evidence suggests that increased expression of the vascular endothelial growth factor (VEGF) co-receptor Neuropilin-2 (NRP2) is associated with aggressive breast cancers and that VEGF/NRP2 signaling contributes to clinical resistance to chemotherapy and tumor recurrence, making NRP2 a promising therapeutic target. A major limitation that has hampered the development of such a therapy, however, has been the lack of availability of high-quality anti-human NRP2 monoclonal antibodies (mAbs) that specifically block VEGF/NRP2 signaling. aTyr has generated a panel of high-quality, anti-human NRP2 mAbs that have the potential to be developed for the clinical management of diseases that involve NRP2 signaling. Among them, ATYR2810 has been characterized to bind to the b1 domain of NRP2 that encompasses the VEGF binding sites. It completely blocks the binding of VEGF to NRP2, and VEGF-induced NRP2/VEGFR dimerization. Importantly, ATYR2810 had no effect on Semaphorin 3F (Sema3F) induced NRP2/PlexinA1 dimerization, demonstrating its specificity for blocking the VEGF/NRP2 pathway. We have shown that ATYR2810, but not a Sema3F-blocking mAb has tumor-inhibitory effects on triple negative breast cancer (TNBC) cell lines or patient-derived organoids. RESULTS: We further evaluated the efficacy of ATYR2810 in combination with standard-of-care therapeutics including Cisplatin and Bevacizumab (anti-VEGF-A blocking antibody). In in vitro 3D methylcellulose colony formation assays, ATYR2810 sensitized TNBC cells to Cisplatin or Bevacizumab and considerably reduced colony formation in combination with these treatments. In an in vivo TNBC xenograft cancer model (MDA-MB-231), ATYR2810 augmented the anti-tumor effects of Cisplatin or Bevacizumab. To explore the underlying molecular mechanism, we performed gene expression profiling with samples treated by ATYR2810 alone and the combo therapy with Cisplatin or Bevacizumab. A number of gene markers of cancer stem cells (CSC) and/or epithelial-mesenchymal transition (EMT) were found to be down-regulated by ATYR2810 treatment in TNBC patient-derived organoids, including a key EMT transcription factor ZEB1. We also confirmed the reduction of ZEB1 protein expression by ATYR2810 treatment in TNBC cells. CONCLUSIONS: These results demonstrate the efficacy of ATYR2810 in combination with standard-of-care therapeutics in in vitro and in vivo TNBC models, and suggest its activity is mediated through inhibiting both EMT and cellular dedifferentiation that renders tumors more sensitive to the treatment regimes. The targeting of VEGF/NRP2 signaling by ATYR2810 may provide a new therapeutic option, and lead to the identification of new treatment biomarkers, which could offer improved efficacy and reduced toxicity in aggressive breast cancers. Citation Format: Zhiwen Xu, Christoph Burkart, Hira L. Goel, Justin Rahman, Clara Polizzi, Matt Seikkula, Luke Burman, Arthur M. Mercurio, Leslie A. Nangle. A domain-specific antibody to NRP2 down-regulated epithelial-mesenchymal transition genes and enhanced efficacy of standard-of-care therapeutics for aggressive breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB095.

Relationship between circulating tumor cells and ZEB1 expression in tumor cells in colorectal cancer.

e15509 Background: Intravasation and circulation of tumor cells involves active invasion of cells with an enhanced migration potential as a result of the epithelial-mesenchymal transition (EMT). The ZEB1 protein is one of the key regulators of this process. Our purpose was to evaluate the association between the amount of circulating tumor cells (CTCs) in the peripheral blood of patients with different stages of colorectal cancer and the expression of ZEB1 by tumor cells. Methods: The study included 299 patients (aged 42-86 years, mean age 64.2±1.7) with stage II-IV CRC T1-4N0-2M0-1; histologically verified G1-G3 adenocarcinoma in all patients. The numbers of CTCs were measured in the peripheral blood before surgery using the Veridex CellSearch system (Janssen). CTCs were registered taking into account morphological characteristics and expression of epithelial cell adhesion markers EpCAM, CD45, cytokeratins 8,18,19. The blood sample was evaluated according to the following criteria: 0 CTCs, 1-3 CTCs, and more than 3 CTCs. Tissues of surgically removed tumors were studied with IHC analysis using rabbit polyclonal anti-ZEB1 antibodies (Biorbyt Ltd.) diluted 1:200 and the Reveal Polyvalent HRP-DAB Detection System. The percentage and the intensity of staining were assessed: 0, 1+ weak, 2+ moderate, 3+ strong. ZEB1 expression was considered positive when staining was detected in more than 10% (cut-off) tumor cells with intensities of 2+ and 3+. Statistical analysis of results was performed in the Statistica 13.0 program (StatSoftInc., USA). Results: From 1 to 402 CTCs were determined in 62.9% cases (in 188 of 299 patients); CTCs were not registered in 37.1% cases (111 of 299). Positive ZEB1 expression was observed in 80.6% (241 of 299 patients), while the negative one was much more rare – 19.4% (58 of 299 patients). The rates of CTC detection significantly increased with the positive ZEB1+ expression, compared to the negative expression (75.1% vs. 12.1%). CTCs &gt;3 were detected in the blood in 39.0% in ZEB1+ tumors, but not in ZEB1- tumors. 1-3 CTCs were observed 3 times more often in ZEB1+ tumors (36.1% vs. 12.1; p≤0.05). Conclusions: Statistically significant association was revealed between the epithelial-mesenchymal transition marker ZEB1 expression by tumor cells and the amount of CTCs in the peripheral blood (p &lt; 0.001).

ZEB1 expression in different stages of colorectal cancer.

e15526 Background: Colorectal cancer (CRC) is among the most common cancers. The leading cause of high mortality is tumor progression developed due to the epithelial to mesenchymal transition (EMT). The ZEB1 protein is one of the critical regulators of this process. In this regard, our study aimed to assess the ZEB1 expression in different stages of colorectal cancer. Methods: This study included samples of 206 patients with stage II-IV CRC aged 42 to 86 years (mean age 64.2±1.7). All patients were divided into three groups: group 1 - patients with T3-4 N0 M0 (stage II) with high-risk factors for recurrence, n = 6; group 2 - patients with T1-4 N1-2 M0 (stage III), n = 88; group 3 - patients with T1-4 N0-2 M1 (stage IV), n = 58. IHC study was performed using polyclonal rabbit antibodies to ZEB1 (Biorbyt Ltd.) diluted 1:200 and a Reveal Polyvalent HRP-DAB Detection System. The staining percentage and intensity were assessed: 0, 1+ weak, 2+ moderate, 3+ strong. The nuclear reaction of the ZEB1 protein was considered positive when staining was detected in more than 10% (cut-off) of tumor cells with intensities of 2+ and 3+. Statistical analysis of the results was carried out using the STATISTICA 13.0 software (StatSoft Inc., USA). Results: A positive nuclear reaction for ZEB1 was detected in 80.6% (166 of 206 patients), while negative in 19.4% (40 of 206 patients). The maximal percentage of patients with positive staining for ZEB1 was among those with stage IV (94.8%), the minimal percentage - stage II (60%). The prevalence of ZEB1+ in patients with stages III and IV significantly increased the risk of tumor progression by 3.5 (95% CI 1.8-8.4) and 12.2 (95% CI 3.4-43.6) times, respectively, compared with stage II patients. No statistical significance was observed in the comparison between patients with stages III and IV (95% CI 0.9-11.7). The percentage of ZEB1+ samples increased in more advanced tumors. The ratio of ZEB1+/ZEB1- tumors in stage II was 1.5, in stage III - 5.8, in stage IV - 18.3 (p &lt; 0.05). Conclusions: The immunohistochemical study revealed the features of ZEB1 expression in different stages of colorectal cancer, which can serve as prognostic factors that determine the disease progression.

Aspirin facilitates trophoblast invasion and epithelial-mesenchymal transition by regulating the miR-200-ZEB1 axis in preeclampsia

Preeclampsia is a severe gestational hypertensive disorder that occurs after 20 weeks’ of gestation. It involves several maternal systems, such as cardiovascular, renal, coagulatory systems, and poses a major threat to the maternal and fetal health. Recent clinical evidence showed that aspirin is an effective preventative treatment for reducing the incidence of premature preeclampsia among high-risk pregnant women, however, the mechanism of drug action is not clear. miR-200 family has been shown to be associated with preeclampsia and upregulated in the plasma and placenta of preeclamptic patients. Here we revealed that miR-200 family inhibited trophoblast invasion and epithelial-mesenchymal transition (EMT) process by stimulating epithelial marker expression (E-cadherin and ZO-1) and repressing mesenchymal marker expression (ZEB1 and TGFβ1). Similarly, EMT markers in the placenta of preeclamptic patients showed higher E-cadherin and lower ZEB1 and TGF-β1 protein expression. Moreover, aspirin was shown to suppress miR-200 family and these miR-200 family-mediated cell functions, including cell invasion and EMT changes, were completely reversed. In conclusion, this study demonstrates the effect of miR-200 family on trophoblast invasion and EMT. For the first time, aspirin was shown to fully reverse miR-200-mediated trophoblast biology and act through the network signaling of TGF-β1/ZEB1/miR-200. These results provide a plausible mechanism explaining aspirin’s effect on preeclampsia prevention and a therapeutic target for disease intervention.

Dual Effect of Taxifolin on ZEB2 Cancer Signaling in HepG2 Cells.

Polyphenols, secondary metabolites of plants, exhibit different anti-cancer and cytoprotective properties such as anti-radical, anti-angiogenic, anti-inflammation, or cardioprotective. Some of these activities could be linked to modulation of miRNAs expression. MiRNAs play an important role in posttranscriptional regulation of their target genes that could be important within cell signalling or preservation of cell homeostasis, e.g., cell survival/apoptosis. We evaluated the influence of a non-toxic concentration of taxifolin and quercetin on the expression of majority human miRNAs via Affymetrix GeneChip™ miRNA 3.0 Array. For the evaluation we used two cell models corresponding to liver tissue, Hep G2 and primary human hepatocytes. The array analysis identified four miRNAs, miR-153, miR-204, miR-211, and miR-377-3p, with reduced expression after taxifolin treatment. All of these miRNAs are linked to modulation of ZEB2 expression in various models. Indeed, ZEB2 protein displayed upregulation after taxifolin treatment in a dose dependent manner. However, the modulation did not lead to epithelial mesenchymal transition. Our data show that taxifolin inhibits Akt phosphorylation, thereby diminishing ZEB2 signalling that could trigger carcinogenesis. We conclude that biological activity of taxifolin may have ambiguous or even contradictory outcomes because of non-specific effect on the cell.