EYA2 promotes lung cancer cell proliferation by downregulating the expression of PTEN

The Eyes Absent family: At the intersection of DNA repair, mitosis, and replication

The Eyes Absent family (EYA1-4) are a group of dual function proteins that act as both tyrosine phosphatases and transcriptional co-activators. EYA proteins play a vital role in development, but are also aberrantly overexpressed in cancers, where they often confer an oncogenic effect. Precisely how the EYAs impact cell biology is of growing interest, fuelled by the therapeutic potential of an expanding repertoire of EYA inhibitors. Recent functional studies suggest that the EYAs are important players in the regulation of genome maintenance pathways including DNA repair, mitosis, and DNA replication. While the characterized molecular mechanisms have predominantly been ascribed to EYA phosphatase activities, EYA co-transcriptional activity has also been found to impact the expression of genes that support these pathways. This indicates functional convergence of EYA phosphatase and co-transcriptional activities, highlighting the emerging importance of the EYA protein family at the intersection of genome maintenance mechanisms. In this review, we discuss recent progress in defining EYA protein substrates and transcriptional effects, specifically in the context of genome maintenance. We then outline future directions relevant to the field and discuss the clinical utility of EYA inhibitors.

An EYA3/NF-κB/CCL2 signaling axis suppresses cytotoxic NK cells in the pre-metastatic niche to promote triple negative breast cancer metastasis

Patients with Triple Negative Breast Cancer (TNBC) exhibit high rates of metastases and poor prognoses. The Eyes absent (EYA) family of proteins are developmental transcriptional cofactors/phosphatases that are re-expressed and/or upregulated in numerous cancers. Herein, we demonstrate that EYA3 correlates with decreased survival in breast cancer, and that it strongly, and specifically, regulates metastasis via a novel mechanism that involves NF-kB signaling and an altered innate immune profile at the pre-metastatic niche (PMN). Remarkably, restoration of NF-kB signaling downstream of Eya3 knockdown (KD) restores metastasis without restoring primary tumor growth, isolating EYA3/NF-kB effects to the metastatic site. We show that secreted CCL2, regulated downstream of EYA3/NF-kB, specifically decreases cytotoxic NK cells in the PMN and that re-expression of Ccl2 in Eya3 -KD cells is sufficient to rescue activation/levels of cytotoxic NK cells in vitro and at the PMN, where EYA3-mediated decreases in cytotoxic NK cells are required for metastatic outgrowth. Importantly, analysis of public breast cancer datasets uncovers a significant correlation of EYA3 with NF-kB/CCL2, underscoring the relevance of EYA3/NF-kB/CCL2 to human disease. Our findings suggest that inhibition of EYA3 could be a powerful means to re-activate the innate immune response at the PMN, inhibiting TNBC metastasis.

Significance

EYA3 promotes metastasis of TNBC cells by promoting NF-kB-mediated CCL2 expression and inhibiting cytotoxic NK cells at the pre-metastatic niche, highlighting a potential therapeutic target in this subset of breast cancer.

Thermal Proteome Profiling Reveals Insight to Antiproliferative and Pro-Apoptotic Effects of Lagunamide A in the Modulation of DNA Damage Repair

Lagunamide A is a biologically active natural product with a yet unidentified molecular mode of action. Cellular studies revealed that lagunamide A is a potent inhibitor of cancer cell proliferation, promotes apoptosis and causes mitochondrial dysfunction. To decipher the cellular mechanism responsible for these effects, we utilized thermal protein profiling (TPP) and identified EYA3 as a stabilized protein in cells upon lagunamide A treatment. EYA3, involved in the DNA damage repair process, was functionally investigated via siRNA based knockdown studies and corresponding effects of lagunamide A on DNA repair were confirmed. Furthermore, we showed that lagunamide A sensitized tumor cells to treatment with the drug doxorubicin highlighting a putative therapeutic strategy.

All eyes on Eya: A unique transcriptional co-activator and phosphatase in cancer

The Eya family of proteins (consisting of Eyas1-4 in mammals) play vital roles in embryogenesis by regulating processes such as proliferation, migration/invasion, cellular survival and pluripotency/plasticity of epithelial and mesenchymal states. Eya proteins carry out such diverse functions through a unique combination of transcriptional co-factor, Tyr phosphatase, and PP2A/B55α-mediated Ser/Thr phosphatase activities. Since their initial discovery, re-expression of Eyas has been observed in numerous tumor types, where they are known to promote tumor progression through a combination of their transcriptional and enzymatic activities. Eya proteins thus reinstate developmental processes during malignancy and represent a compelling class of therapeutic targets for inhibiting tumor progression.

The Eyes Absent family members EYA4 and EYA1 promote PLK1 activation and successful mitosis through tyrosine dephosphorylation

The Eyes Absent proteins (EYA1-4) are a biochemically unique group of tyrosine phosphatases known to be tumour-promoting across a range of cancer types. To date, the targets of EYA phosphatase activity remain largely uncharacterised. Here, we identify Polo-like kinase 1 (PLK1) as an interactor and phosphatase substrate of EYA4 and EYA1, with pY445 on PLK1 being the primary target site. Dephosphorylation of pY445 in the G2 phase of the cell cycle is required for centrosome maturation, PLK1 localization to centrosomes, and polo-box domain (PBD) dependent interactions between PLK1 and PLK1-activation complexes. Molecular dynamics simulations support the rationale that pY445 confers a structural impairment to PBD-substrate interactions that is relieved by EYA-mediated dephosphorylation. Depletion of EYA4 or EYA1, or chemical inhibition of EYA phosphatase activity, dramatically reduces PLK1 activation, causing mitotic defects and cell death. Overall, we have characterized a phosphotyrosine signalling network governing PLK1 and mitosis.

In Vitro Phosphatase Assays for the Eya2 Tyrosine Phosphatase

Protein tyrosine phosphatases (PTP), such as the Eyes Absent (Eya) family of proteins, play important roles in diverse biological processes. In vitro phosphatase assays are essential tools for characterizing the enzymatic activity as well as discovering inhibitors and regulators of these phosphatases. Two common types of in vitro phosphatase assays use either a small molecule substrate that produces a fluorescent or colored product, or a peptide substrate that produces a colorimetric product in a malachite green assay. In this chapter, we describe detailed protocols of a phosphatase assay using small molecule 3-O-methylfluorescein phosphate (OMFP) as a substrate and a malachite green assay using the pH2AX peptide as a substrate to evaluate the phosphatase activity of EYA2 and the effect of small molecule inhibitors of EYA2. These protocols can be easily adapted to study other protein tyrosine phosphatases.

EYA2 tyrosine phosphatase inhibition reduces MYC and prevents medulloblastoma progression

BACKGROUND

Medulloblastoma is the most common pediatric brain malignancy. Patients with the Group 3 subtype of medulloblastoma (MB) often exhibit MYC amplification and/or overexpression and have the poorest prognosis. While Group 3 MB is known to be highly dependent on MYC, direct targeting of MYC remains elusive.

METHODS

Patient gene expression data were used to identify highly expressed EYA2 in Group 3 MB samples, assess the correlation between EYA2 and MYC, and examine patient survival. Genetic and pharmacological studies were performed on EYA2 in Group 3 derived MB cell models to assess MYC regulation and viability in vitro and in vivo.

RESULTS

EYA2 is more highly expressed in Group 3 MB than other MB subgroups and is essential for Group 3 MB growth in vitro and in vivo. EYA2 regulates MYC expression and protein stability in Group 3 MB, resulting in global alterations of MYC transcription. Inhibition of EYA2 tyrosine phosphatase activity, using a novel small molecule inhibitor (NCGC00249987, or 9987), significantly decreases Group 3 MB MYC expression in both flank and intracranial growth in vivo. Human MB RNA-seq data show that EYA2 and MYC are significantly positively correlated, high EYA2 expression is significantly associated with a MYC transcriptional signature, and patients with high EYA2 and MYC expression have worse prognoses than those that do not express both genes at high levels.

CONCLUSIONS

Our data demonstrate that EYA2 is a critical regulator of MYC in Group 3 MB and suggest a novel therapeutic avenue to target this highly lethal disease.

EYA4 promotes breast cancer progression and metastasis through its role in replication stress avoidance

The Eyes Absent (EYA) family of proteins is an atypical group of four dual-functioning protein phosphatases (PP), which have been linked to many vital cellular processes and organogenesis pathways. The four family members of this PP family possess transcriptional activation and phosphatase functions, with serine/threonine and tyrosine phosphatase domains. EYA4 has been associated with several human cancers, with tumor-suppressing and tumor-promoting roles. However, EYA4 is the least well-characterized member of this unique family of PP, with its biological functions and molecular mechanisms in cancer progression, particularly in breast cancer, still largely unknown. In the present study, we found that the over-expression of EYA4 in breast tissue leads to an aggressive and invasive breast cancer phenotype, while the inhibition of EYA4 reduced tumorigenic properties of breast cancer cells in vitro and in vivo. Cellular changes downstream of EYA4, including cell proliferation and migration, may explain the increased metastatic power of breast cancer cells over-expressing EYA4. Mechanistically, EYA4 prevents genome instability by inhibiting the accumulation of replication-associated DNA damage. Its depletion results in polyploidy as a consequence of endoreplication, a phenomenon that can occur in response to stress. The absence of EYA4 leads to spontaneous replication stress characterized by the activation of the ATR pathway, sensitivity to hydroxyurea, and accumulation of endogenous DNA damage as indicated by increased γH2AX levels. In addition, we show that EYA4, specifically its serine/threonine phosphatase domain, plays an important and so far, unexpected role in replication fork progression. This phosphatase activity is essential for breast cancer progression and metastasis. Taken together, our data indicate that EYA4 is a novel potential breast cancer oncogene that supports primary tumor growth and metastasis. Developing therapeutics aimed at the serine/threonine phosphatase activity of EYA4 represents a robust strategy for killing breast cancer cells, to limit metastasis and overcome chemotherapy resistance caused by endoreplication and genomic rearrangements.

EYA4 drives breast cancer progression and metastasis through its novel role in replication stress avoidance

The Eyes Absent (EYA) family of proteins is an atypical group of four dual-functioning protein phosphatases, which have been linked to many vital cellular processes and organogenesis pathways. Like the other isoforms, EYA4 possesses transcriptional activation and phosphatase functions, with serine/threonine and tyrosine phosphatase domains. EYA4 has been associated with several human cancers, with tumor-suppressing and tumor-promoting roles. However, EYA4 is the least well-characterized member of this unique family of phosphatases, with its biological functions and molecular mechanisms in cancer progression, particularly in breast cancer, still largely unknown. In the present study, we found that the over-expression of EYA4 in breast tissue leads to an aggressive and invasive breast cancer phenotype, while the inhibition of EYA4 reduced tumorigenic properties of breast cancer cells in vitro and in vivo . Cellular changes downstream of EYA4, including cell proliferation and migration, may explain the increased metastatic power of breast cancer cells over-expressing EYA4. Mechanistically, EYA4 prevents genome instability by inhibiting the accumulation of replication-associated DNA damage. Its depletion results in polyploidy as a consequence of endoreplication, a phenomenon that can occur in response to stress. The absence of EYA4 leads to spontaneous replication stress characterized by the activation of the ATR pathway, sensitivity to hydroxyurea, and accumulation of endogenous DNA damage as indicated by increased γH2AX levels. In addition, we show that EYA4, specifically its serine/threonine phosphatase domain, plays an important and so far, unexpected role in replication fork progression. This phosphatase activity is essential for breast cancer progression and metastasis. Taken together, our data indicate that EYA4 is a novel breast cancer oncogene that supports primary tumor growth and metastasis. Developing therapeutics aimed at the serine/threonine phosphatase activity of EYA4 represents a robust strategy for killing breast cancer cells, to limit metastasis and overcome chemotherapy resistance caused by endoreplication and genomic rearrangements.

The value of EYA1/3/4 in clear cell renal cell carcinoma: a study from multiple databases

There is evidence from multiple studies that dysregulation of the Eyes Absent (EYA) protein plays multiple roles in many cancers. Despite this, little is known about the prognostic significance of the EYAs family in clear cell renal cell carcinoma (ccRCC). We systematically analyzed the value of EYAs in Clear Cell Renal Cell Carcinoma. Our analysis included examining transcriptional levels, mutations, methylated modifications, co-expression, protein-protein interactions (PPIs), immune infiltration, single-cell sequencing, drug sensitivity, and prognostic values. We based our analysis on data from several databases, including the Cancer Genome Atlas database (TCGA), the Gene Expression Omnibus database (GEO), UALCAN, TIMER, Gene Expression Profiling Interactive Analysis (GEPIA), STRING, cBioPortal and GSCALite. In patients with ccRCC, the EYA1 gene was significantly highly expressed, while the expression of EYA2/3/4 genes showed the opposite trend. The level of expression of the EYA1/3/4 gene was significantly correlated with the prognosis and clinicopathological parameters of ccRCC patients. Univariate and multifactorial Cox regression analyses revealed EYA1/3 as an independent prognostic factor for ccRCC, establishing nomogram line plots with good predictive power. Meanwhile, the number of mutations in EYAs was also significantly correlated with poor overall survival (OS) and progression-free survival (PFS) of patients with ccRCC. Mechanistically, EYAs genes play an essential role in a wide range of biological processes such as DNA metabolism and double-strand break repair in ccRCC. The majority of EYAs members were related to the infiltration of immune cells, drug sensitivity, and methylation levels. Furthermore, our experiment confirmed that EYA1 gene expression was upregulated, and EYA2/3/4 showed low expression in ccRCC. The increased expression of EYA1 might play an important role in ccRCC oncogenesis, and the decreased expression of EYA3/4 could function as a tumor suppressor, suggesting EYA1/3/4 might serve as valuable prognostic markers and potential new therapeutic targets for ccRCC.

Structure-activity relationship studies of allosteric inhibitors of EYA2 tyrosine phosphatase

Human eyes absent (EYA) proteins possess Tyr phosphatase activity, which is critical for numerous cancer and metastasis promoting activities, making it an attractive target for cancer therapy. In this work, we demonstrate that the inhibitor-bound form of EYA2 does not favour binding to Mg2+ , which is indispensable for the Tyr phosphatase activity. We further describe characterization and optimization of this class of allosteric inhibitors. A series of analogues were synthesized to improve potency of the inhibitors and to elucidate structure-activity relationships. Two co-crystal structures confirm the binding modes of this class of inhibitors. Our medicinal chemical, structural, biochemical, and biophysical studies provide insight into the molecular interactions of EYA2 with these allosteric inhibitors. The compounds derived from this study are useful for exploring the function of the Tyr phosphatase activity of EYA2 in normal and cancerous cells and serve as reference compounds for screening or developing allosteric phosphatase inhibitors. Finally, the co-crystal structures reported in this study will aid in structure-based drug discovery against EYA2.

Recent advances in the development of allosteric protein tyrosine phosphatase inhibitors for drug discovery

Protein tyrosine phosphatases (PTPs) superfamily catalyzes tyrosine de-phosphorylation which affects a myriad of cellular processes. Imbalance in signal pathways mediated by PTPs has been associated with development of many human diseases including cancer, metabolic, and immunological diseases. Several compelling evidence suggest that many members of PTP family are novel therapeutic targets. However, the clinical development of conventional PTP-based active-site inhibitors originally was hampered by the poor selectivity and pharmacokinetic properties. In this regard, PTPs has been widely dismissed as "undruggable." Nonetheless, allosteric modulation has become increasingly an influential and alternative approach that can be exploited for drug development against PTPs. Unlike active-site inhibitors, allosteric inhibitors exhibit a remarkable target-selectivity, drug-likeness, potency, and in vivo activity. Intriguingly, there has been a high interest in novel allosteric PTPs inhibitors within the last years. In this review, we focus on the recent advances of allosteric inhibitors that have been explored in drug discovery and have shown an excellent result in the development of PTPs-based therapeutics. A special emphasis is placed on the structure-activity relationship and molecular mechanistic studies illustrating applications in chemical biology and medicinal chemistry.

Targeting EYA2 tyrosine phosphatase activity in glioblastoma stem cells induces mitotic catastrophe

Glioblastoma ranks among the most lethal of primary brain malignancies, with glioblastoma stem cells (GSCs) at the apex of tumor cellular hierarchies. Here, to discover novel therapeutic GSC targets, we interrogated gene expression profiles from GSCs, differentiated glioblastoma cells (DGCs), and neural stem cells (NSCs), revealing EYA2 as preferentially expressed by GSCs. Targeting EYA2 impaired GSC maintenance and induced cell cycle arrest, apoptosis, and loss of self-renewal. EYA2 displayed novel localization to centrosomes in GSCs, and EYA2 tyrosine (Tyr) phosphatase activity was essential for proper mitotic spindle assembly and survival of GSCs. Inhibition of the EYA2 Tyr phosphatase activity, via genetic or pharmacological means, mimicked EYA2 loss in GSCs in vitro and extended the survival of tumor-bearing mice. Supporting the clinical relevance of these findings, EYA2 portends poor patient prognosis in glioblastoma. Collectively, our data indicate that EYA2 phosphatase function plays selective critical roles in the growth and survival of GSCs, potentially offering a high therapeutic index for EYA2 inhibitors.

Role of SIX1, EYA2, and E-cadherin in ovarian carcinoma. Evidence on epithelial-mesenchymal transition from an immunohistochemical study

This study aims to investigate the expression of SIX1, EYA2, and E-cadherin in ovarian cancer (OC). It was conducted on 97 cases of surface epithelial tumors (SEOTs). Immunohistochemistry (IHC) staining for the three markers was applied to archival paraffin-embedded sections. Results of semi-quantitative scoring were statistically compared, correlated with clinic-pathologic parameters, response to therapy and with patient survival. RESULTS: There was a significant association of SIX1 expression in the intratumoral stroma (ITS) with malignant cases (P < 0.0001). There was a significant direct correlation between tumour cell expression of SIX1 and EYA2 (P = 0.03) and an inverse correlation between SIX1 and E-cadherin (P = 0.03). Additionally, there were direct correlations between SIX1 expression and larger tumour size (P = 0.05), high mitosis (P < 0.0001), and advanced FIGO stage (P = 0.06), and between EYA2 expression and LN metastasis (P = 0.02), and low apoptotic index (P = 0.007). Only SIX1 expression in ITS affected the patient survival by univariate analysis (P = 0.004). CONCLUSIONS: SIX1/EYA2 complex may have a poor prognostic role in OC. SIX1 expression in ITS may be used as a predictive marker of stromal invasion in ovarian borderline tumors and could affect patients' survival in OC. SIX1, EYA2, and E-cadherin may constitute a pathway that could be targeted to stop the progression of SEOTs.

EYA2 suppresses the progression of hepatocellular carcinoma via SOCS3-mediated blockade of JAK/STAT signaling

BACKGROUND

Somatic mutations are involved in hepatocellular carcinoma (HCC) progression, but the genetic mechanism associated to hepatocarcinogenesis remains poorly understood. We report that Eyes absent homolog 2 (EYA2) suppresses the HCC progression, while EYA2(A510E) mutation identified by exome sequencing attenuates the tumor-inhibiting effect of EYA2.

METHODS

Whole-exome sequencing was performed on six pairs of human HCC primary tumors and matched adjacent tissues. Focusing on EYA2, expression level of EYA2 in human HCC samples was evaluated by quantitative real-time PCR, western blot and immunohistochemistry. Loss- and gain-of-function studies, hepatocyte-specific deletion of EYA2 (Eya2-/-) in mice and RNA sequencing analysis were used to explore the functional effect and mechanism of EYA2 on HCC cell growth and metastasis. EYA2 methylation status was evaluated using Sequenom MassARRAY and publicly available data analysis.

RESULTS

A new somatic mutation p.Ala510Glu of EYA2 was identified in HCC tissues. The expression of EYA2 was down-regulated in HCC and associated with tumor size (P = 0.001), Barcelona Clinic Liver Cancer stage (P = 0.016) and tumor differentiation (P = 0.048). High level of EYA2 was correlated with a favorable prognosis in HCC patients (P = 0.003). Results from loss-of-function and gain-of-function experiments suggested that knockdown of EYA2 enhanced, while overexpression of EYA2 attenuated, the proliferation, clone formation, invasion, and migration of HCC cells in vitro. Delivery of EYA2 gene had a therapeutic effect on inhibition of orthotopic liver tumor in nude mice. However, EYA2(A510E) mutation led to protein degradation by unfolded protein response, thus weakening the inhibitory function of EYA2. Hepatocyte-specific deletion of EYA2 in mice dramatically promoted diethylnitrosamine-induced HCC development. EYA2 was also down-regulated in HCC by aberrant CpG methylation. Mechanically, EYA2 combined with DACH1 to transcriptionally regulate SOCS3 expression, thus suppressing the progression of HCC via SOCS3-mediated blockade of the JAK/STAT signaling pathway.

CONCLUSIONS

In our study, we identified and validated EYA2 as a tumor suppressor gene in HCC, providing a new insight into HCC pathogenesis.

Discovery of New Protein Targets of BPA Analogs and Derivatives Associated with Noncommunicable Diseases: A Virtual High-Throughput Screening

BACKGROUND

Bisphenol A analogs and derivatives (BPs) have emerged as new contaminants with little or no information about their toxicity. These have been found in numerous everyday products, from thermal paper receipts to plastic containers, and measured in human samples.

OBJECTIVES

The objectives of this research were to identify in silico new protein targets of BPs associated with seven noncommunicable diseases (NCDs), and to study their protein-ligand interactions using computer-aided tools.

METHODS

Fifty BPs were identified by a literature search and submitted to a virtual high-throughput screening (vHTS) with 328 proteins associated with NCDs. Protein-protein interactions between predicted targets were examined using STRING, and the protocol was validated in terms of binding site recognition and correlation between in silico affinities and in vitro data.

RESULTS

According to the vHTS, several BPs may target proteins associated with NCDs, some of them with stronger affinities than bisphenol A (BPA). The best affinity score (the highest in silico affinity absolute value) was obtained after docking 4,4'-bis(N-carbamoyl-4-methylbenzensulfonamide)diphenylmethane (BTUM) on estradiol 17-beta-dehydrogenase 1 (-13.7 kcal/mol). However, other molecules, such as bisphenol A bis(diphenyl phosphate) (BDP), bisphenol PH (BPPH), and Pergafast 201 also exhibited great affinities (top 10 affinity scores for each disease) with proteins related to NCDs.

DISCUSSION

Molecules such as BTUM, BDP, BPPH, and Pergafast 201 could be targeting key signaling pathways related to NCDs. These BPs should be prioritized for in vitro and in vivo toxicity testing and to further assess their possible role in the development of these diseases. https://doi.org/10.1289/EHP7466.

EYA2 upregulates miR-93 to promote tumorigenesis of breast cancer by targeting and inhibiting the STING signaling pathway

Herein, we used DIANA TOOLS, GEPIA and other bioinformatics databases to predict regulatory pathways in breast cancer. Accordingly, we clarified the regulatory mechanism of EYA2 on miR-93 expression to aggravate breast cancer, which was involved with the STING signaling pathway. CCK-8 assay, scratch test, Transwell assay, and flow cytometry were applied to detect cell viability, migration, invasion, and apoptosis. The experimental data found that EYA2 was highly expressed in breast cancer tissues and cells and associated with poor prognosis. Overexpression of miR-93 in breast cancer was positively correlated with EYA2. EYA2 promoted miR-93 expression, advanced breast cancer cell proliferation and inhibited their apoptosis. Results of luciferase assay showed that miR-93 was enriched in the STING 3'UTR. Furthermore, knockdown of EYA2 inhibited the expression of miR-93, promoted the expression of STING, and inhibited the tumor growth. In response to EYA2 knockdown, the expression of IFN-β and ISG was increased, and PD-L1 was decreased. In addition, the phosphorylation level of TBK1 and IRF3 was enhanced, the percentage of myeloid-derived suppressor cells in blood was reduced, and secretion of IFN-β and IL-12 was enhanced. In conclusion, EYA2 upregulates miR-93 expression and promotes malignancy of breast cancer by targeting and inhibiting the STING signaling pathway.

Probing biological mechanisms with chemical tools

Traditionally small molecules have mainly been used to inhibit biochemical activities of proteins, however such compounds can also be used to change the conformational energy landscape of proteins. Tool compounds that modulate protein conformations often reveal unexpected biological mechanisms, which have therapeutic potential. We discuss two examples where screening hits were found to bind to unexpected binding pockets on well known proteins, establishing new routes for the inhibition of proteins that were thought to be undruggable.

PTEN in Lung Cancer: Dealing with the Problem, Building on New Knowledge and Turning the Game Around

Lung cancer is the most common malignancy and cause of cancer deaths worldwide, owing to the dismal prognosis for most affected patients. Phosphatase and tensin homolog deleted in chromosome 10 (PTEN) acts as a powerful tumor suppressor gene and even partial reduction of its levels increases cancer susceptibility. While the most validated anti-oncogenic duty of PTEN is the negative regulation of the PI3K/mTOR/Akt oncogenic signaling pathway, further tumor suppressor functions, such as chromosomal integrity and DNA repair have been reported. PTEN protein loss is a frequent event in lung cancer, but genetic alterations are not equally detected. It has been demonstrated that its expression is regulated at multiple genetic and epigenetic levels and deeper delineation of these mechanisms might provide fertile ground for upgrading lung cancer therapeutics. Today, PTEN expression is usually determined by immunohistochemistry and low protein levels have been associated with decreased survival in lung cancer. Moreover, available data involve PTEN mutations and loss of activity with resistance to targeted treatments and immunotherapy. This review discusses the current knowledge about PTEN status in lung cancer, highlighting the prevalence of its alterations in the disease, the regulatory mechanisms and the implications of PTEN on available treatment options.

Structural and Functional Analyses of an Allosteric EYA2 Phosphatase Inhibitor That Has On-Target Effects in Human Lung Cancer Cells

EYA proteins (EYA1-4) are critical developmental transcriptional cofactors that contain an EYA domain (ED) harboring Tyr phosphatase activity. EYA proteins are largely downregulated after embryogenesis but are reexpressed in cancers, and their Tyr phosphatase activity plays an important role in the DNA damage response and tumor progression. We previously identified a class of small-molecule allosteric inhibitors that specifically inhibit the Tyr phosphatase activity of EYA2. Herein, we determined the crystal structure of the EYA2 ED in complex with NCGC00249987 (a representative compound in this class), revealing that it binds to an induced pocket distant from the active site. NCGC00249987 binding leads to a conformational change of the active site that is unfavorable for Mg²⁺ binding, thereby inhibiting EYA2's Tyr phosphatase activity. We demonstrate, using genetic mutations, that migration, invadopodia formation, and invasion of lung adenocarcinoma cells are dependent on EYA2 Tyr phosphatase activity, whereas growth and survival are not. Further, we demonstrate that NCGC00249987 specifically targets migration, invadopodia formation, and invasion of lung cancer cells, but that it does not inhibit cell growth or survival. The compound has no effect on lung cancer cells carrying an EYA2 F290Y mutant that abolishes compound binding, indicating that NCGC00249987 is on target in lung cancer cells. These data suggest that the NCGC00249987 allosteric inhibitor can be used as a chemical probe to study the function of the EYA2 Tyr phosphatase activity in cells and may have the potential to be developed into an antimetastatic agent for cancers reliant on EYA2's Tyr phosphatase activity.

Eya2 Is Overexpressed in Human Prostate Cancer and Regulates Docetaxel Sensitivity and Mitochondrial Membrane Potential through AKT/Bcl-2 Signaling

The aberrant expression of Eya2 has been observed in a wide range of cancer types. However, the clinical significance and biological effects of EYA2 in human prostate cancer remain unknown. In this study, we showed that increased levels of Eya2 protein correlated with advanced TNM stage, T stage, and a higher Gleason score. Data from the Cancer Genome Atlas (TCGA) prostate cohort consistently revealed that Eya2 mRNA was positively correlated with a higher Gleason score, higher T stage, and positive nodal metastasis in prostate cancer. Furthermore, data from the Oncomine database showed increased levels of EYA2 mRNA expression in prostate cancer tissues compared with normal tissues. Eya2 protein expression was also higher in prostate cancer cell lines compared with a normal RWPE-1 cell line. We selected LNCaP and PC-3 cell lines for plasmid overexpression and shRNA knockdown. CCK-8, colony formation, and Matrigel invasion assays demonstrated that the overexpression of Eya2 promoted proliferation, colony number, and invasion while Eya2 shRNA inhibited proliferation rate, colony formation, and invasion ability. CCK-8 and Annexin V assays showed that Eya2 reduced sensitivity to docetaxel and docetaxel-induced apoptosis while Eya2 shRNA showed the opposite effects. The overexpression of Eya2 also downregulated the cleavage of caspase3 and PARP while Eya2 depletion upregulated caspase3 and PARP cleavage. Notably, JC-1 staining demonstrated that Eya2 upregulated mitochondrial membrane potential. We further revealed that the overexpression of Eya2 upregulated Bcl-2, matrix metalloproteinase 7 (MMP7), and AKT phosphorylation. Accordingly, data from the TCGA prostate cohort indicated that EYA2 mRNA was positively correlated with the expression of Bcl-2 and MMP7. The inhibition of AKT attenuated EYA2-induced Bcl-2 upregulation. In conclusion, our data demonstrated that Eya2 was upregulated in prostate cancers. EYA2 promotes cell proliferation and invasion as well as cancer progression by regulating docetaxel sensitivity and mitochondrial membrane potential, possibly via the AKT/Bcl-2 axis.

Profiling of differentially expressed genes in cadmium-induced prostate carcinogenesis

The aim of the present study was to investigate the genetic signatures of cadmium-transformed prostate epithelial (CTPE) cells and to identify the potential molecular signaling involved in their malignant transformation. The dataset contained normal prostate epithelial (RWPE-1) and CTPE cells. To further examine the biological functions of the identified differentially expressed genes (DEGs), Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Reactome pathway enrichment analyses were performed. In total, 2357 DEGs were identified, including 1083 upregulated genes and 1274 downregulated genes. GO, KEGG, and Reactome pathway enrichment analyses indicated that upregulated genes were significantly enriched in ECM-receptor, focal adhesion, TGFβ signaling, and syndecan interactions, while downregulated genes were mainly involved in cell cycle regulation, arachidonic acid metabolism, oxidative phosphorylation, and folate biosynthesis (p < .05). The top upregulated (SATB1 (p < .0001), EYA2 (p < .0001) and KPNA7 (p < .0027)) and downregulated (PITX2 (p < .0007), PDLIM4 (p < .0020) and FABP5 (p < .0007)) genes were further validated via qRT-PCR analysis. In conclusion, the present study profiled DEGs in RWPE-1 and CTPE cells and identified gene pathways that may be associated with malignant transformation and tumor progression.

EYA2 Correlates With Clinico-Pathological Features of Breast Cancer, Promotes Tumor Proliferation, and Predicts Poor Survival

Eyes absent homolog 2 (EYA2), a transcriptional activator, is pivotal for organ development, but aberrant regulation of EYA2 has been reported in multiple human tumors. However, the role of EYA2 in breast cancer is still lack of full understanding. To explore the biological significance of EYA2 in breast cancer, we conducted data analysis on public breast cancer datasets, and performed immunohistochemistry (IHC) analysis, colony-forming unit assays, EdU assay, western blotting, and immunofluorescence (IF). Meta-analysis showed that EYA2 mRNA expression was correlated with tumor grade, the status of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2). IHC analysis displayed that EYA2 protein abundance was inversely associated with the status of ER and PR, and enriched in triple-negative breast cancer in comparison with luminal-type tumors. Additionally, correlation analysis reflected that EYA2 mRNA was negatively correlated with luminal markers, and positively associated with markers of basal cells, epithelial-mesenchymal transition and cancer stem cells. Clone-forming assay and EdU experiment showed that EYA2 overexpression enhanced proliferation of breast cancer cells. Results from western blotting and IF displayed that overexpression of EYA2 up-regulated the protein abundance of proliferation markers. Importantly, survival analysis indicated that higher EYA2 mRNA level predicted worse overall survival, relapse-free survival and metastasis-free survival among whole enrolled breast cancer patients. Collectively, EYA2 was closely correlated with clinico-pathological characteristics, and served as a proliferation stimulator for breast cancer cells and an unfavorable prognostic element for breast cancer patients, suggesting that EYA2 is involved in the progression of breast carcinoma.

miR-219a-5p represses migration and invasion of osteosarcoma cells via targeting EYA2

EYA2 is the developmental transcription factor and phosphatase, playing an important role in numerous species in regulating cell death and differentiation. Recent studies showed that EYA2 is dysregulated and involved in the progression of various cancers. However, the expression and role of EYA2 in osteosarcoma remains unclear. Here, we found that EYA2 expression was evidently upregulated osteosarcoma (OS) tissue and cell lines. Next, we predicted EYA2-targeting miRNAs, which was further evaluated using a dual luciferase reporter assay. We found that miR-219a-5p significantly repressed EYA2 expression via binding to the 3'-UTR of EYA2. Furthermore, overexpressed miR-219a-5p significantly repressed OS cell invasion and migration, which was reversed by overexpressed EYA2. While silenced miR-219a-5p induced OS cell invasion and migration, which was reversed by silenced EYA2. In conclusion, our study revealed that miR-219a-5p function as tumour suppressor regulates OS cell invasiveness by repressing EYA2 expression.

Molecular mechanism and role of microRNA-93 in human cancers: A study based on bioinformatics analysis, meta-analysis, and quantitative polymerase chain reaction validation

INTRODUCTION

Currently, studies have shown that microRNA-93 (miR-93) can be an oncogene or a tumor suppressor in different kinds of cancers. The role of miR-93 in human cancers is inconsistent and the underlying mechanism on the aberrant expression of miR-93 is complicated.

METHODS

We first conducted gene enrichment analysis to give insight into the prospective mechanism of miR-93. Second, we performed a meta-analysis to evaluate the clinical value of miR-93. Finally, a validation test based on quantitative polymerase chain reaction (qPCR) was performed to further investigate the role of miR-93 in pan-cancer.

RESULTS

Gene Ontology (GO) enrichment analysis results showed that the target genes of miR-93 were closely related to transcription, and MAPK1, RBBP7 and Smad7 became the hub genes. In the diagnostic meta-analysis, the overall sensitivity, specificity, and area under the curve were 0.76 (0.64-0.85), 0.82 (0.64-0.92), and 0.85 (0.82-0.88), respectively, which suggested that miR-93 had excellent performance on the diagnosis for human cancers. In the prognostic meta-analysis, dysregulated miR-93 was found to be associated with poor OS in cancer patients. In the qPCR validation test, the serum levels of miR-93 were upregulated in breast cancer, breast hyperplasia, lung cancer, chronic obstructive pulmonary disease, nasopharyngeal cancer, hepatocellular cancer, gastric ulcer, endometrial cancer, esophageal cancer, laryngeal cancer, and prostate cancer compared with healthy controls.

CONCLUSIONS

miR-93 could act as an effective diagnostic and prognostic factor for cancer patients. Its clinical value for cancer early diagnosis and survival prediction is promising.