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Project description:A SIX1/EYA2 small molecule inhibitor disrupts EMT and metastasis
| PRJNA635948 | ENA
Project description:Metastasis is the major cause of mortality for patients with cancer, and dysregulation of developmental signaling pathways can significantly contribute to the metastatic process. The Sine oculis homeobox homolog 1 (SIX1)/eyes absent (EYA) transcriptional complex plays a critical role in the development of multiple organs and is typically downregulated after development is complete. In breast cancer, aberrant expression of SIX1 has been demonstrated to stimulate metastasis through activation of TGF? signaling and subsequent induction of epithelial-mesenchymal transition (EMT). In addition, SIX1 can induce metastasis via non-cell autonomous means, including activation of GLI-signaling in neighboring tumor cells and activation of VEGFC-induced lymphangiogenesis. Thus, targeting SIX1 would be expected to inhibit metastasis while conferring limited side effects. However, transcription factors are notoriously difficult to target, and thus novel approaches to inhibit their action must be taken. Here we identified a novel small molecule compound, NCGC00378430 (abbreviated as 8430), that reduces the SIX1/EYA2 interaction. 8430 partially reversed transcriptional and metabolic profiles mediated by SIX1 overexpression and reversed SIX1-induced TGF? signaling and EMT. 8430 was well tolerated when delivered to mice and significantly suppressed breast cancer-associated metastasis in vivo without significantly altering primary tumor growth. Thus, we have demonstrated for the first time that pharmacologic inhibition of the SIX1/EYA2 complex and associated phenotypes is sufficient to suppress breast cancer metastasis. SIGNIFICANCE: These findings identify and characterize a novel inhibitor of the SIX1/EYA2 complex that reverses EMT phenotypes suppressing breast cancer metastasis.
| S-EPMC7510951 | biostudies-literature
Project description:Inappropriate activation of developmental pathways is a well-recognized tumor-promoting mechanism. Here we show that overexpression of the homeoprotein Six1, normally a developmentally restricted transcriptional regulator, increases Transforming Growth Factor-beta (TGF-beta) signaling in mammary carcinoma cells and induces an epithelial to mesenchymal transition (EMT) that is in part dependent on its ability to increase TGF-beta signaling. TGF-beta signaling and EMT have been implicated in metastatic dissemination of carcinoma. Using spontaneous and experimental metastasis mouse models, we demonstrate that Six1 overexpression promotes breast cancer metastasis. In addition, we show that, like its induction of EMT, Six1-induced experimental metastasis is dependent on its ability to activate TGF-beta signaling. Importantly, in human breast cancers Six1 significantly correlates with nuclear Smad3, and thus increased TGF-beta signaling. Further, breast cancer patients whose tumors overexpress Six1 have a shortened time to relapse and metastasis, and an overall decrease in survival. Finally, we show that the effects of Six1 on tumor progression likely extend beyond breast cancer, since its overexpression correlates with adverse outcomes in numerous other cancers, including brain, cervical, prostate, colon, kidney, and liver, amongst others. Our findings argue that Six1, acting through TGF-beta signaling and EMT, is a powerful and global promoter of cancer metastasis.
2010-08-21 | GSE23655 | GEO
Project description:Recent fate mapping studies concluded that EMT is not required for metastasis of carcinomas. Here we challenge this conclusion by showing that it failed to account for possible crosstalk between EMT and non-EMT cells that promotes dissemination of non-EMT cells. In breast cancer models, EMT cells induce increased metastasis of weakly metastatic, non-EMT tumor cells in a paracrine manner in part by non-cell autonomous activation of the GLI transcription factor. Treatment with GANT61, a GLI1/2 inhibitor, but not with IPI-926, a Smoothened inhibitor, blocks this effect, and inhibits growth in PDX models. In human breast tumors, the EMT-TFs strongly correlate with activated Hedgehog/GLI signaling, but not with the Hh ligands. Our findings indicate that EMT contributes to metastasis in part via non-cell autonomous effects that activate the Hh pathway. While all Hh inhibitors may act against tumors with canonical Hh/GLI signaling, only GLI inhibitors would act against EMT-induced GLI activation. In recent years, immunohistochemical analyses and multiplex high-throughput single cell sequencing of human tumor cells have shown that tumors are composed of diverse cell subpopulations containing different driver mutations, gene and protein expression profiles, growth rates, and responses to chemotherapeutics. Such heterogeneity is exacerbated by cellular plasticity, where some cells may undergo oncogenic epithelial-to-mesenchymal transition (EMT), resulting in loss of cell-cell adhesion and polarity, reduced epithelial and elevated mesenchymal protein expression, increased migration and invasion, and enhanced dissemination from the primary tumor. Because metastases in patients appear epithelial, the reverse process, mesenchymal-to-epithelial transition (MET), may occur to allow tumor cell colonization in secondary metastatic sites, establishing cellular plasticity as an important aspect of tumor progression. However, the role of EMT in carcinoma metastasis is controversial. Recent lineage tracing studies argue against the requirement of EMT for metastasis, as reporter-tagged cells that underwent a previous EMT were not found at the secondary site. However, these studies did not address the potential cooperation between EMT and non-EMT cells during the metastatic process, as EMT cancer cells may enable non-EMT cells to gain access to the secondary site, leading to macrometastatic growth. Thus, metastasis can be influenced by intratumoral heterogeneity: where a small proportion of primary tumor cells that have undergone an EMT may influence neighboring, non-EMT tumor cells. Twist1, Snail1, and Six1 are EMT-inducing transcription factors (EMT-TFs) that have all been associated with breast cancer metastasis. All three EMT-TFs regulate critical developmental processes such as cell survival, migration and invasion; in part by influencing EMT. In addition, they are downregulated post-embryogenesis, but re-expressed in various cancers where they cell autonomously induce EMT, resulting in increased percentages of tumor initiating cells (TICs) and enhanced metastasis. In carcinomas, Twist1 and Snail1 transcriptionally repress E-Cadherin (E- Cad) and upregulate mesenchymal genes. Similarly, Six1 overexpression induces EMT by regulating E-Cad localization and altering other EMT markers. During development and cancer, EMT-TFs act in concert with several signaling networks including TGFβ, Wnt, and Hedghog (Hh). The Hedgehog (Hh) signaling pathway is a prominent regulator of embryonic development, where Hh ligands function as morphogens to control numerous developmental processes. Interestingly, in Drosophila eye development, hh is a direct target of sine oculis (the homolog of Six1) and Six1 regulates Hh/GLI signaling during lung development and in fibroblasts. Additionally, Twist1 and Hh/GLI signaling are intimately linked during development, and recently Twist1 and Snail1 were associated with the Hh pathway in TICs. In mammals, canonical activation of Hh/GLI signaling involves binding of one the Hh ligands such as(either, Desert (DHH), Indian (IHH), or Sonic Hedgehog (SHH) to Patched-1 (PTCH1) or Patched-2 (PTCH2) receptors, relieving the inhibitory activity of PTCH on Smoothened (SMO). When inhibition is relieved, levels of the transcriptional activator forms of one or more GLI transcription factors (GLI1, 2, or 3) increase in the nucleus, resulting in activation of Hh target genes 12. Non-canonical activation of the GLI TFs can occur in a Hh- or SMO-independent manner via secreted factors like TGF-β19. Importantly, autocrine and paracrine Hh-mediated crosstalk between tumor cells and the tumor microenvironment 20 results in increased proliferation, stem cell self-renewal and metastasis in various cancers 21. In basal cell carcinoma (BCC) and medulloblastoma, activated Hh signaling is often due to mutations in pathway components such as PTCH and SMO, while in other tumor types including breast, mutations are not observed at high frequency. Instead there is evidence for Hh ligand-dependent pathway hyperactivity. Because numerous studies link Hh signaling to progression in multiple tumor types, derivatives of cyclopamine (e.g. GDC-0449 and IPI926), a naturally occurring plant-derived steroidal alkaloid which targets SMO, are in clinical trials for select patients with BCC and medulloblastoma with promising efficacy. However, these inhibitors have not shown promise in breast cancer despite evidence for activation of this pathway. Herein, we demonstrate that EMT-TFs Twist1, Snail1 and Six1 influence neighboring carcinoma cells in a non-cell autonomous manner, by increasing EMT features and aggressive properties of cells not expressing these TFs. Six1 is a key mediator of the non-cell autonomous effects downstream of Twist1 and Snail1, and can induce metastasis of non-Six1, non-EMT cells. All three EMT-TFs function non-cell autonomously by activation of GLI-mediated transcription in non-EMT cells, but employ different mechanisms of pathway activation, some of which are Hh ligand and SMO-independent. We find that pharmacological inhibition of GLI, but not SMO, in the non-EMT cells efficiently inhibits the non-cell autonomous phenotypes imparted by all three EMT-TFs. Importantly, we demonstrate that in selected patient derived breast cancer xenograft (PDX) models endogenously expressing high levels of these EMT-TFs (but not Hh ligands), GANT61 (a GLI1/2 inhibitor) inhibits tumor growth whereas IPI926 (a SMO inhibitor) did not. Our data suggest that upstream SMO inhibitors may not prove efficacious in tumors where a proportion of cells activate GLI-TF via EMT-TFs, and instead argue that inhibitors directly targeting GLI may be more effective.
2017-04-13 | GSE97726 | GEO
Project description:The homeodomain transcription factor SIX1 plays a critical role in embryogenesis, is not expressed in normal adult tissue, but is expressed in many malignancies, including cervical cancer. SIX1 drives the progression of HPV16-immortalized human keratinocytes (HKc/HPV16) toward malignancy: HKc/HPV16 express high levels of SIX1 mRNA and protein; overexpression of SIX1 in HKc/HPV16 produces pre-malignant, differentiation-resistant lines (HKc/DR); SIX1 overexpression in HKc/DR induces tumorigenicity. In this paper, we explore the consequences of inhibition of SIX1 expression in premalignant HKc/DR. Only partial inhibition of SIX1 expression could be obtained in HKc/DR by RNA interference. Decreased SIX1 expression (up to 80%) in HKc/DR resulted in slower proliferation, decreased HPV16-E6/E7 mRNA levels, and increased p53 protein levels. Gene expression changes induced in HKc/DR by anti-SIX1 shRNA were indicative of mesenchymal-epithelial transition (EMT) and changes in TGF-beta signaling. We conclude that HPV16-transformed cells depend on SIX1 for survival, continuous HPV16 E6/E7 gene expression and EMT.
2019-08-20 | GSE126926 | GEO
Project description:Carcinoma cells can acquire key malignant traits by reprogramming their differentiation state via an epithelial-to-mesenchymal transition (EMT). Cancer cells that undergo EMT become invasive and resist a wide range of therapies including most chemotherapy drugs and radiation. Such cells are also able to efficiently seed primary and metastatic tumors, making them functionally indistinguishable from tumor-initiating or cancer stem-like cells (TICs or CSCs). Therefore, there is significant interest in finding vulnerabilities of cancer cells that have undergone EMT. A potent EMT-selective small molecule was discovered through a large-scale chemical screen. We used microarray analysis to understand the biological effects of this compound. HMLE_ctrl (human MECs, infected with a pBabe-shGFP retrovirus) and HMLE_Twist (human MECs, infected with a pBabe-Twist retrovirus) cells were treated with solvent control (DMSO), 5 µM or 10 µM of Cmp302 for 6 hours. Microarray analysis was performed to profile global gene expression.
2014-04-09 | E-GEOD-55604 | biostudies-arrayexpress
Project description:Carcinoma cells can acquire key malignant traits by reprogramming their differentiation state via an epithelial-to-mesenchymal transition (EMT). Cancer cells that undergo EMT become invasive and resist a wide range of therapies including most chemotherapy drugs and radiation. Such cells are also able to efficiently seed primary and metastatic tumors, making them functionally indistinguishable from tumor-initiating or cancer stem-like cells (TICs or CSCs). Therefore, there is significant interest in finding vulnerabilities of cancer cells that have undergone EMT. A potent EMT-selective small molecule was discovered through a large-scale chemical screen. We used microarray analysis to understand the biological effects of this compound.
2014-04-09 | GSE55604 | GEO
Project description:SIX1 interacts with EYA to form a bipartite transcription factor essential for mammalian development. Loss of function of this complex causes branchio-oto-renal (BOR) syndrome, whereas re-expression of SIX1 or EYA promotes metastasis. Here we describe the 2.0-Å structure of SIX1 bound to EYA2, which suggests a new DNA-binding mechanism for SIX1 and provides a rationale for the effect of BOR syndrome mutations. The structure also reveals that SIX1 uses predominantly a single helix to interact with EYA. Substitution of a single amino acid in this helix is sufficient to disrupt SIX1-EYA interaction, SIX1-mediated epithelial-mesenchymal transition and metastasis in mouse models. Given that SIX1 and EYA are overexpressed in many tumor types, our data indicate that targeting the SIX1-EYA complex may be a potent approach to inhibit tumor progression in multiple cancer types.
| S-EPMC3618615 | biostudies-literature
Project description:Investigating genomic binding of SIX1 in A673 cells transduced with shSCR or one of two shSIX1 shRNAs to deplete SIX1.
2023-05-22 | GSE215350 | GEO
Project description:Investigating genomic binding of SIX1 in EWS-502 cells transduced with shSCR or one of two shSIX1 shRNAs to deplete SIX1.
2023-05-22 | GSE233118 | GEO