Targeting the DNA-binding activity of the human ERG transcription factor using new heterocyclic dithiophene diamidines

Induction of AML cell differentiation using HOXA9/DNA binding inhibitors as a potential therapeutic option for HOXA9-dependent AML

The mainstay of acute myeloid leukemia (AML) treatment still relies on traditional chemotherapy, with a survival rate of approximately 30% for patients under 65 years of age and as low as 5% for those beyond. This unfavorable prognosis primarily stems from frequent relapses, resistance to chemotherapy, and limited approved targeted therapies for specific AML subtypes. Around 70% of all AML cases show overexpression of the transcription factor HOXA9, which is associated with a poor prognosis, increased chemoresistance, and higher relapse rates. However, direct targeting of HOXA9 in a clinical setting has not been achieved yet. The dysregulation caused by the leukemic HOXA9 transcription factor primarily results from its binding activity to DNA, leading to differentiation blockade. Our previous investigations have identified two HOXA9/DNA binding competitors, namely DB1055 and DB818. We assessed their antileukemic effects in comparison to HOXA9 knockdown or cytarabine treatment. Using human AML cell models, DB1055 and DB818 induced in vitro cell growth reduction, death, differentiation, and common transcriptomic deregulation but did not impact human CD34+ bone marrow cells. Furthermore, DB1055 and DB818 exhibited potent antileukemic activities in a human THP-1 AML in vivo model, leading to the differentiation of monocytes into macrophages. In vitro assays also demonstrated the efficacy of DB1055 and DB818 against AML blasts from patients, with DB1055 successfully reducing leukemia burden in patient-derived xenografts in NSG immunodeficient mice. Our findings indicate that inhibiting HOXA9/DNA interaction using DNA ligands may offer a novel differentiation therapy for the future treatment of AML patients dependent on HOXA9.

Transcription Factors in Prostate Cancer: Insights for Disease Development and Diagnostic and Therapeutic Approaches

Transcription factors (TFs) are proteins essential for the regulation of gene expression, and they regulate the genes involved in different cellular processes, such as proliferation, differentiation, survival, and apoptosis. Although their expression is essential in normal physiological conditions, abnormal regulation of TFs plays critical role in several diseases, including cancer. In prostate cancer, the most common malignancy in men, TFs are known to play crucial roles in the initiation, progression, and resistance to therapy of the disease. Understanding the interplay between these TFs and their downstream targets provides insights into the molecular basis of prostate cancer pathogenesis. In this review, we discuss the involvement of key TFs, including the E26 Transformation-Specific (ETS) Family (ERG and SPDEF), NF-κB, Activating Protein-1 (AP-1), MYC, and androgen receptor (AR), in prostate cancer while focusing on the molecular mechanisms involved in prostate cancer development. We also discuss emerging diagnostic strategies, early detection, and risk stratification using TFs. Furthermore, we explore the development of therapeutic interventions targeting TF pathways, including the use of small molecule inhibitors, gene therapies, and immunotherapies, aimed at disrupting oncogenic TF signaling and improving patient outcomes. Understanding the complex regulation of TFs in prostate cancer provides valuable insights into disease biology, which ultimately may lead to advancing precision approaches for patients.

Poly(ADP-ribose) Polyremase-1 (PARP-1) Inhibition: A Promising Therapeutic Strategy for ETS-Expressing Tumours

ETS transcription factors are a highly conserved family of proteins involved in the progression of many cancers, such as breast and prostate carcinomas, Ewing's sarcoma, and leukaemias. This significant involvement can be explained by their roles at all stages of carcinogenesis progression. Generally, their expression in tumours is associated with a poor prognosis and an aggressive phenotype. Until now, no efficient therapeutic strategy had emerged to specifically target ETS-expressing tumours. Nevertheless, there is evidence that pharmacological inhibition of poly(ADP-ribose) polymerase-1 (PARP-1), a key DNA repair enzyme, specifically sensitises ETS-expressing cancer cells to DNA damage and limits tumour progression by leading some of the cancer cells to death. These effects result from a strong interplay between ETS transcription factors and the PARP-1 enzyme. This review summarises the existing knowledge of this molecular interaction and discusses the promising therapeutic applications.

Interaction of the platinum complex of tyrosine-β-cyclodextrin with G-quadruplex DNA

The telomeric quadruplex structures formed by the guanine-rich sequences of DNA have emerged as targets for small molecules designed and synthesized to stabilize the G-quadruplexes. This report presents a newly synthesized tyrosine-tethered cyclodextrin derivative and its platinum complex. Their structures are characterized using IR, NMR, and mass spectral techniques. The binding interactions of the platinum complex with CT-DNA and the kit22, myc22, and telo24 G-quadruplexes are investigated employing absorption and fluorescence spectral titrations. The binding constant or KSV values of the interaction with the G-quadruplexes are more significant than those with the duplex DNA by order of 10. It presents the compound as a G-quadruplex-selective binder. Further, the well-known G-quadruplex binding molecule Berberine is encapsulated in the Tyr- β-CD through a host: guest association. The structure of the host: guest complex is investigated employing 2D ROESY spectroscopy. In addition, the study on the binding interaction of the complex to the DNA targets is also carried out. The mode and strength of interaction of the free and the Berberine-loaded Tyr-β-CD to the duplex and the quadruplexes are reported.

Emerging Developments in ETS-Positive Prostate Cancer Therapy

Prostate cancer is a global health concern, which has a low survival rate in its advanced stages. Even though second-generation androgen receptor-axis inhibitors serve as the mainstay treatment options, utmost of the metastatic cases progress into castration-resistant prostate cancer after their initial treatment response with poor prognostic outcomes. Hence, there is a dire need to develop effective inhibitors that aim the causal oncogenes tangled in the prostate cancer initiation and progression. Molecular-targeted therapy against E-26 transformation-specific (ETS) transcription factors, particularly ETS-related gene, has gained wide attention as a potential treatment strategy. ETS rearrangements with the male hormone responsive transmembrane protease serine 2 promoter defines a significant number of prostate cancer cases and is responsible for cancer initiation and progression. Notably, inhibition of ETS activity has shown to reduce tumorigenesis, thus highlighting its potential as a clinical therapeutic target. In this review, we recapitulate the various targeted drug approaches, including small molecules, peptidomimetics, nucleic acids, and many others, aimed to suppress ETS activity. Several inhibitors have demonstrated ERG antagonist activity in prostate cancer, but further investigations into their molecular mechanisms and impacts on nontumor ETS-containing tissues is warranted.

New thiophene derivative augments the antitumor activity of γ-irradiation against colorectal cancer in mice via anti-inflammatory and pro-apoptotic pathways

BACKGROUND

Colorectal cancer (CRC) is one of the most common types of cancer worldwide and the second cause of cancer-related deaths. It usually starts as an inflammation that progresses to adenocarcinoma. The goal of the present study was to investigate the antitumor efficacy of a new thiophene derivative against CRC in mice and explore the possible associated molecular pathways. The potential of this thiophene derivative to sensitize the CRC tumor tissue to a low dose of gamma irradiation was also investigated.

METHODS

Adult male mice were divided into seven groups; control, group treated with dimethylhydrazine (DMH) for the induction of CRC. The DMH-group was further divided into six groups and treated with either cisplatin, thiophene derivative, γ-irradiation, cisplatin + γ-irradiation, thiophene derivative + γ-irradiation, or left untreated.

RESULTS

DMH induced CRC as evidenced by the macroscopic examination of colon tissues and histopathology, and elevated the activities of cyclooxygenase2 (COX2) and nitric oxide synthase (iNOS). DMH also elevated kirsten rat sarcoma (KRAS) and downregulated the peroxisome proliferator activated receptor (PPARγ) as shown by RT-PCR and Western blotting. DMH exerted anti-apoptotic activity by reducing the expression of phosphorylated p53 and cleaved caspase3 at the gene and protein levels. The flow cytometry analysis showed that DMH elevated the necrosis and reduced the apoptosis compared to the other groups. The colon tissue from DMH-treated mice showed hyperplasia, aberrant crypt foci, loss of cell polarity, typical CRC of grade 4 with lymphocytes and macrophages infiltrating mucosa, muscularis mucosa, and submucosa score 3. Treatment with thiophene derivative or γ-irradiation ameliorated most of these deleterious effects of DMH. The concomitant action of thiophene derivative + γ-irradiation was typified by the better amelioration of tumor incidence and multiplicity, iNOS, PPARγ, p53, caspase 3, and histopathology of colon.

CONCLUSION

Taken together, the new thiophene derivative is a promising therapeutic candidate for treatment of colorectal cancer in mice. It also sensitizes the CRC tumor to the ionizing radiation through anti-inflammatory and pro-apoptotic pathways.

PGC1 alpha coactivates ERG fusion to drive antioxidant target genes under metabolic stress

The presence of ERG gene fusion; from developing prostatic intraepithelial neoplasia (PIN) lesions to hormone resistant high grade prostate cancer (PCa) dictates disease progression, altered androgen metabolism, proliferation and metastasis^1–3. ERG driven transcriptional landscape may provide pro-tumorigenic cues in overcoming various strains like hypoxia, nutrient deprivation, inflammation and oxidative stress. However, insights on the androgen independent regulation and function of ERG during stress are limited. Here, we identify PGC1α as a coactivator of ERG fusion under various metabolic stress. Deacetylase SIRT1 is necessary for PGC1α-ERG interaction and function. We reveal that ERG drives the expression of antioxidant genes; SOD1 and TXN, benefitting PCa growth. We observe increased expression of these antioxidant genes in patients with high ERG expression correlates with poor survival. Inhibition of PGC1α-ERG axis driven transcriptional program results in apoptosis and reduction in PCa xenografts. Here we report a function of ERG under metabolic stress which warrants further studies as a therapeutic target for ERG fusion positive PCa.

PGC1α acts as a co-activator of the ERG transcription factor during metabolic stress resulting in antioxidant functionsand inhibition of the PGC1α-ERG driven transcriptional program reduces prostate cancer growth by inducing ROS mediated apoptosis.

Past, Current, and Future Strategies to Target ERG Fusion-Positive Prostate Cancer

Simple Summary

In addition to its role in development and in the vascular and hematopoietic systems, ERG plays a central role in prostate cancer. Approximately 40–50% of prostate cancer cases are characterized by ERG gene fusions, which lead to ERG overexpression. Importantly, inhibition of ERG activity in prostate cancer cells decreases their viability. Therefore, inhibiting ERG might represent an important step to improve treatment efficacy for patients with ERG-positive prostate tumors. Here, we summarize the attempts made over the past years to repress ERG activity, the current use of ERG fusion detection and the strategies that might be utilized in the future to treat ERG fusion-positive tumors.

Abstract

The ETS family member ERG is a transcription factor with physiological roles during development and in the vascular and hematopoietic systems. ERG oncogenic activity characterizes several malignancies, including Ewing’s sarcoma, leukemia and prostate cancer (PCa). In PCa, ERG rearrangements with androgen-regulated genes—mostly TMPRSS2—characterize a large subset of patients across disease progression and result in androgen receptor (AR)-mediated overexpression of ERG in the prostate cells. Importantly, PCa cells overexpressing ERG are dependent on ERG activity for survival, further highlighting its therapeutic potential. Here, we review the current understanding of the role of ERG and its partners in PCa. We discuss the strategies developed in recent years to inhibit ERG activity, the current therapeutic utility of ERG fusion detection in PCa patients, and the possible future approaches to target ERG fusion-positive tumors.

The Antitumor Activity of a Novel Fluorobenzamidine against Dimethylhydrazine- Induced Colorectal Cancer in Rats

BACKGROUND

Colorectal cancer is among the leading causes of death worldwide. The incidence of deaths is expected to be 11.4 million in 2030.

OBJECTIVE

We aimed to evaluate the in vitro and in vivo antioxidant and antitumor activities of a novel Bithiophene- Fluorobenzamidine (BFB) against DMH-induced colorectal cancer in rats.

METHODS

The antiproliferative activity of BFB against HCT-116 colon cancer cells and apoptotic genes was assessed. In vivo study was also conducted in which 80 adult male rats were divided into 5 groups; control, BFB, and the other 3 groups were injected with DMH (20mg/kg, s.c., for 9 weeks). Group 4 was injected with 5 doses of cisplatin (2.5mg/kg, i.p over 21 weeks) and group 5 was injected with 3 doses/week of BFB (2.5mg/kg, i.p, for 21 weeks).

RESULTS

BFB exhibited weak to moderate in vitro antioxidant activity. It had a strong antiproliferative activity with IC50 ~0.3µg/ml. BFB induced extrinsic apoptosis through the upregulation of FasL, TRAL, p53 and caspase-8, and intrinsic apoptosis through the downregulation of Bcl-2 and survivin. BFB decreased the tumor incidence, multiplicity and size and improved the decreased body weight. BFB also ameliorated the functions of kidney and liver and antioxidants deteriorated by DMH. BFB significantly improved the pathological changes caused by DMH in colon tissues.

CONCLUSION

BFB showed a very promising antitumor activity against colorectal cancer induced by DMH in rats without causing hepato- or nephrotoxicity.

Molecular genomic features associated with in vitro response of the NCI-60 cancer cell line panel to natural products

Natural products remain a significant source of anticancer chemotherapeutics. The search for targeted drugs for cancer treatment includes consideration of natural products, which may provide new opportunities for antitumor cytotoxicity as single agents or in combination therapy. We examined the association of molecular genomic features in the well-characterized NCI-60 cancer cell line panel with in vitro response to treatment with 1302 small molecules which included natural products, semisynthetic natural product derivatives, and synthetic compounds based on a natural product pharmacophore from the Developmental Therapeutics Program of the US National Cancer Institute's database. These compounds were obtained from a variety of plant, marine, and microbial species. Molecular information utilized for the analysis included expression measures for 23059 annotated transcripts, lncRNAs, and miRNAs, and data on protein-changing single nucleotide variants in 211 cancer-related genes. We found associations of expression of multiple genes including SLFN11, CYP2J2, EPHX1, GPC1, ELF3, and MGMT involved in DNA damage repair, NOTCH family members, ABC and SLC transporters, and both mutations in tyrosine kinases and BRAF V600E with NCI-60 responses to specific categories of natural products. Hierarchical clustering identified groups of natural products, which correlated with a specific mechanism of action. Specifically, several natural product clusters were associated with SLFN11 gene expression, suggesting that potential action of these compounds may involve DNA damage. The associations between gene expression or genome alterations of functionally relevant genes with the response of cancer cells to natural products provide new information about potential mechanisms of action of these identified clusters of compounds with potentially similar biological effects. This information will assist in future drug discovery and in design of new targeted cancer chemotherapy agents.

Biological Insights of Fluoroaryl-2,2'-Bichalcophene Compounds on Multi-Drug Resistant Staphylococcus aureus

Resistance of bacteria to multiple antibiotics is a significant health problem; hence, to continually respond to this challenge, different antibacterial agents must be constantly discovered. In this work, fluoroaryl-2,2'-bichalcophene derivatives were chemically synthesized and their biological activities were evaluated against Staphylococcus aureus (S. aureus). The impact of the investigated bichalcophene derivatives was studied on the ultrastructural level via scanning electron microscopy (SEM), molecular level via sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) method and on the biofilm inhibition via the electrochemical biosensors. Arylbichalcophenes' antibacterial activity against S. aureus was affected by the presence and location of fluorine atoms. The fluorobithiophene derivative MA-1156 displayed the best minimum inhibitory concentration (MIC) value of 16 µM among the tested fluoroarylbichalcophenes. Over a period of seven days, S. aureus did not develop any resistance against the tested fluoroarylbichalcophenes at higher concentrations. The impact of fluoroarylbichalcophenes was strong on S. aureus protein pattern showing high degrees of polymorphism. SEM micrographs of S. aureus cells treated with fluoroarylbichalcophenes displayed smaller cell-sizes, fewer numbers, arranged in a linear form and some of them were damaged when compared to the untreated cells. The bioelectrochemical measurements demonstrated the strong sensitivity of S. aureus cells to the tested fluoroarylbichalcophenes and an antibiofilm agent. Eventually, these fluoroarylbichalcophene compounds especially the MA-1156 could be recommended as effective antibacterial agents.

Synthesis of new thienylpicolinamidine derivatives and possible mechanisms of antiproliferative activity

Three thienylpicolinamidine derivatives 4a-c were prepared from their corresponding picolinonitriles 3a-c on treatment with lithium trimethylsilylamide, LiN(TMS)2, followed by a de-protection step using ethanol/HCl (gas). DFT calculations were used to optimize the geometric structure of the newly synthesized picolinamidines. The comparison of DFT calculated spectral data with the experimental data (1H-NMR and 13C-NMR) showed a good agreement. The in vitro antiproliferative activity of the cationic compounds 4a-c was determined against 60 cancer cell lines representing nine types of cancer. The tested picolinamidines were highly active with compounds 4a and 4b eliciting mainly cytotoxic activity with GI values ranging from -7.17 to -86.03. Leukemia (SR and K-562), colon (SW-620 and HT29), and non-small cell lung cancer (NCI-H460) cell lines were the most responsive to the investigated picolinamidines. In particular, 4-methoxyphenyl derivative 4a showed a profound growth deterring power with GI50 of 0.34 μM against SR, 0.43 μM against SW-620, and 0.52 μM against NCI-H460. The three tested picolinamidines elicited potent GI50 values against all tested cell lines at low micromolar to sub-micromolar level. The new picolinamidines were selective and did not affect normal human fibroblasts. The selectivity index ranged from 13-21 μM. The novel picolinamidines downregulated the expression of key genes in the cell cycle, cdk1 and topoII, but did not affect p53 or txnrd1. Compounds 4b and 4c caused a significant reduction in the concentrations of TopoII and MAPK proteins but were devoid of any effect on the activity of caspase 3. Taken together, these promising anticancer candidates are effective at very low concentrations and safe to normal cells, and most probably work through arresting the cell cycle, and therefore, they deserve further investigations.

A water-soluble bithiophene with increased photoluminescence efficiency and metal recognition ability

A new water-soluble tri-tert-butyl-bithiophenesulfonamide (α2-tbS) was synthesized and a comprehensive spectroscopic and photophysical study was undertaken in organic solvents and water at different pH values. In contrast to the behaviour found for the parent (and un-substituted) α,α'-bithiophene (α2), in which radiationless decay processes are the main excited-state deactivation channels, the tert-butylsulfonamide derivative presents a significant fluorescence quantum yield (φF) (ca. one order of magnitude higher than that of α2). The high φF allowed further exploring α2-tbS as a selective fluorimetric sensor for metal ions. A strong selectivity towards Cu(ii) is observed at neutral pH values, whereas at pH = 9.5 a strong quenching upon the addition of Hg(ii) is observed. An additional high sensitivity of 0.64 ± 0.02 ppm towards Cu(ii) was observed, well below 1.25 ppm (∼20 μM), the maximum value allowed in drinking water by the EPA.

Alternative Strategies to Inhibit Tumor Vascularization

Endothelial cells present in tumors show different origin, phenotype, and genotype with respect to the normal counterpart. Various mechanisms of intra-tumor vasculogenesis sustain the complexity of tumor vasculature, which can be further modified by signals deriving from the tumor microenvironment. As a result, resistance to anti-VEGF therapy and activation of compensatory pathways remain a challenge in the treatment of cancer patients, revealing the need to explore alternative strategies to the classical anti-angiogenic drugs. In this review, we will describe some alternative strategies to inhibit tumor vascularization, including targeting of antigens and signaling pathways overexpressed by tumor endothelial cells, the development of endothelial vaccinations, and the use of extracellular vesicles. In addition, anti-angiogenic drugs with normalizing effects on tumor vessels will be discussed. Finally, we will present the concept of endothelial demesenchymalization as an alternative approach to restore normal endothelial cell phenotype.

Aberrant ERG expression associates with downregulation of miR-4638-5p and selected genomic alterations in a subset of diffuse large B-cell lymphoma

ERG (avian v-ets erythroblastosis virus E26 oncogene homolog), an oncoprotein in prostate carcinoma and Ewing's sarcoma is associated with poor prognosis in patients with acute myeloid leukemia and T lymphoblastic leukemia. However little is known about ERG in lymphoma. Here we studied ERG in diffuse large B-cell lymphoma (DLBCL) by immunohistochemistry, fluorescence in situ hybridization (FISH), genome-wide microRNA (miRNA) expression profiling, real-time reverse-transcriptase polymerase chain reaction (RT-PCR) and whole exome sequencing (WES). Approximately 30% of de novo DLBCLs (37 of 118) expressed ERG (ERG+). ERG expression showed no significant correlation with DLBCL cell-of-origin classification, patient's age, sex, nodal, or extranodal disease status, tumor expression of p53 or p63. There was no ERG rearrangement in 10 randomly selected ERG+ DLBCLs by FISH. Forty-three miRNAs showed significant differential expression between ERG+ and ERG- DLBCLs. Downregulation of miR-4638-5p was confirmed by real-time RT-PCR. WES not only confirmed known gene mutations in DLBCLs but also revealed multiple novel gene mutations in POLA1, E2F1, PSMD8, AXIN1, GAB2, and GNB2L1, which occur more frequently in ERG+ DLBCLs. In conclusion, our studies demonstrated aberrant ERG expression in a subset of DLBCL, which is associated with downregulation of miR-4638-5p. In comparison with ERG-negative DLBCL, ERG+ DLBCL more likely harbors mutations in genes important in cell cycle control, B-cell receptor-mediated signaling and degradation of β-catenin. Further clinicopathological correlation and functional studies of ERG-related miRNAs and pathways may provide new insight into the pathogenesis of DLBCL and reveal novel targets for better management of patients with DLBCL.

ETS transcription factors as emerging drug targets in cancer

The ETS family of proteins consists of 28 transcription factors, many of which have been implicated in development and progression of a variety of cancers. While one family member, ERG, has been rigorously studied in the context of prostate cancer where it plays a critical role, other ETS factors keep emerging as potential hallmark oncodrivers. In recent years, numerous studies have reported initial discoveries of small molecule inhibitors of ETS proteins and opened novel avenues for ETS-directed cancer therapies. This review summarizes the state of the art data on therapeutic targeting of ETS family members and highlights the corresponding drug discovery strategies.

Heterocyclic Diamidine DNA Ligands as HOXA9 Transcription Factor Inhibitors: Design, Molecular Evaluation, and Cellular Consequences in a HOXA9-Dependant Leukemia Cell Model

Most transcription factors were for a long time considered as undruggable targets because of the absence of binding pockets for direct targeting. HOXA9, implicated in acute myeloid leukemia, is one of them. To date, only indirect targeting of HOXA9 expression or multitarget HOX/PBX protein/protein interaction inhibitors has been developed. As an attractive alternative by inhibiting the DNA binding, we selected a series of heterocyclic diamidines as efficient competitors for the HOXA9/DNA interaction through binding as minor groove DNA ligands on the HOXA9 cognate sequence. Selected DB818 and DB1055 compounds altered HOXA9-mediated transcription in luciferase assays, cell survival, and cell cycle, but increased cell death and granulocyte/monocyte differentiation, two main HOXA9 functions also highlighted using transcriptomic analysis of DB818-treated murine Hoxa9-transformed hematopoietic cells. Altogether, these data demonstrate for the first time the propensity of sequence-selective DNA ligands to inhibit HOXA9/DNA binding both in vitro and in a murine Hoxa9-dependent leukemic cell model.

Oncogenic ETS Factors in Prostate Cancer

Prostate cancer is unique among carcinomas in that a fusion gene created by a chromosomal rearrangement is a common driver of the disease. The TMPRSS2/ERG rearrangement drives aberrant expression of the ETS family transcription factor ERG in 50% of prostate tumors. Similar rearrangements promote aberrant expression of the ETS family transcription factors ETV1 and ETV4 in another 10% of cases. Together, these three ETS factors are thought to promote tumorigenesis in the majority of prostate cancers. A goal of precision medicine is to be able to apply targeted therapeutics that are specific to disease subtypes. ETS gene rearrangement positive tumors represent the largest molecular subtype of prostate cancer, but to date there is no treatment specific to this marker. In this chapter we will review the latest findings regarding the molecular mechanisms of ETS factor function in the prostate. These molecular details may provide a path towards new therapeutic targets for this subtype of prostate cancer. Further, we will describe efforts to target the oncogenic functions of ETS family transcription factors directly as well as indirectly.

DNA recognition by linear indole-biphenyl DNA minor groove ligands

Linear heterocyclic cations are interesting DNA minor groove ligands due to their lack of isohelical curvature classically associated with groove-binding compounds. We determined the DNA binding properties of four related dications harboring a linear indole-biphenyl core: the diamidine DB1883, a ditetrahydropyrimidine derivative (DB1804), and their monocationic counterparts (DB1944 and DB2627). These compounds exhibit heterogeneity in binding in accordance with their structures. Whereas the monocations exhibit salt-sensitive 1:1 binding to the duplex 5'-CGCGAATTCGCG-3' (A₂T₂), the dications show a marked preference for a salt-insensitive 2:1 complex. The two binding modes are differentially modulated by salt and specific non-ionic co-solutes. For both dications, 2-methyl-2,4-pentanediol enforces 1:1 binding as observed crystallographically. Fluorescence quenching studies show self-association without DNA in a relative order that is correlated with preference for the 2:1 complex. The data support a structure-binding relationship in which favorable cation-π interactions drive dimer formation via antiparallel stacking of the linear indole-biphenyl cation motif.

Comparative structure analysis of the ETSi domain of ERG3 and its complex with the E74 promoter DNA sequence

ERG3 (ETS-related gene) is a member of the ETS (erythroblast transformation-specific) family of transcription factors, which contain a highly conserved DNA-binding domain. The ETS family of transcription factors differ in their binding to promoter DNA sequences, and the mechanism of their DNA-sequence discrimination is little known. In the current study, crystals of the ETSi domain (the ETS domain of ERG3 containing a CID motif) in space group P41212 and of its complex with the E74 DNA sequence (DNA9) in space group C2221 were obtained and their structures were determined. Comparative structure analysis of the ETSi domain and its complex with DNA9 with previously determined structures of the ERGi domain (the ETS domain of ERG containing inhibitory motifs) in space group P65212 and of the ERGi-DNA12 complex in space group P41212 were performed. The ETSi domain is observed as a homodimer in solution as well as in the crystallographic asymmetric unit. Superposition of the structure of the ETSi domain on that of the ERGi domain showed a major conformational change at the C-terminal DNA-binding autoinhibitory (CID) motif, while minor changes are observed in the loop regions of the ETSi-domain structure. The ETSi-DNA9 complex in space group C2221 forms a structure that is quite similar to that of the ERG-DNA12 complex in space group P41212. Upon superposition of the complexes, major conformational changes are observed at the 5' and 3' ends of DNA9, while the conformation of the core GGA nucleotides was quite conserved. Comparison of the ETSi-DNA9 structure with known structures of ETS class 1 protein-DNA complexes shows the similarities and differences in the promoter DNA binding and specificity of the class 1 ETS proteins.

Mononuclear copper(II) complexes with 2-thiophene carboxylate and N-N donors; DNA interaction, antioxidant/anti-inflammatory and antitumor activity

Redox-active compounds such as copper-phenanthroline are known as artificial/chemical nucleases with a great impact and potential for their applications as metallotherapeutics. In that vein, the mononuclear copper(II) complexes [Cu(L)₂(bipy)] (1), [Cu(L)₂(bipy)(H₂O)] (2) and [Cu(L)₂(phen)(H₂O)] (3), where L = 2-thiophene carboxylate, bipy = 2,2΄-bipyridine and phen = 1,10-phenanthroline, have been prepared and pharmacochemically studied, while the crystal structure of 1 is also reported. All the tested complexes preferably bind to CT-DNA via minor groove as resulted from UV spectroscopy studies, luminescent titration, EB competition assays and viscosity measurements. Complexes 2 and 3 in aqua behave like a "light switch" for DNA. The intensity enhancement, with the increase of DNA concentration, reached about 3-fold for 2 and 10-fold for 3. In vitro antioxidant activity of compounds 1-3, was evaluated using two different antioxidant assays: a) interaction with 1,1-diphenyl-2-picryl-hydrazyl (DPPH) stable free radical and b) inhibition of lipid peroxidation. Moreover, their inhibitory activity on soybean lipoxygenase (LOX) was evaluated for their anti-inflammatory potency. The tested complexes showed good activity on both lipid peroxidation and soybean LOX inhibition while complex 2 exhibited the best antioxidant/anti-inflammatory activity. A computational analysis over the LOX protein structure 1JNQ was performed, in an effort to support their possible mode of action. The cytotoxicity of the complexes was determined and their efficacy against several human cancer cell lines (ovarian, OAW-42; lung, A549; colon, HT29; breast, MDA-MB-231; kidney, Caki-2; and cervical, Hela) and human non-tumor cell lines (lung, MRC-5; and breast, MTSV1-7) were evaluated. The best cytotoxic activity was appeared for complex 3. In silico, computational methods support antiestrogen activity of the administered complexes on normal breast cells.

ELF3, ELF5, EHF and SPDEF Transcription Factors in Tissue Homeostasis and Cancer

The epithelium-specific ETS (ESE) transcription factors (ELF3, ELF5, EHF and SPDEF) are defined by their highly conserved ETS DNA binding domain and predominant epithelial-specific expression profile. ESE transcription factors maintain normal cell homeostasis and differentiation of a number of epithelial tissues, and their genetic alteration and deregulated expression has been linked to the progression of several epithelial cancers. Herein we review the normal function of the ESE transcription factors, the mechanisms by which they are dysregulated in cancers, and the current evidence for their role in cancer progression. Finally, we discuss potential therapeutic strategies for targeting or reactivating these factors as a novel means of cancer treatment.

Targeting Transcription Factors for Cancer Treatment

Transcription factors are involved in a large number of human diseases such as cancers for which they account for about 20% of all oncogenes identified so far. For long time, with the exception of ligand-inducible nuclear receptors, transcription factors were considered as “undruggable” targets. Advances knowledge of these transcription factors, in terms of structure, function (expression, degradation, interaction with co-factors and other proteins) and the dynamics of their mode of binding to DNA has changed this postulate and paved the way for new therapies targeted against transcription factors. Here, we discuss various ways to target transcription factors in cancer models: by modulating their expression or degradation, by blocking protein/protein interactions, by targeting the transcription factor itself to prevent its DNA binding either through a binding pocket or at the DNA-interacting site, some of these inhibitors being currently used or evaluated for cancer treatment. Such different targeting of transcription factors by small molecules is facilitated by modern chemistry developing a wide variety of original molecules designed to specifically abort transcription factor and by an increased knowledge of their pathological implication through the use of new technologies in order to make it possible to improve therapeutic control of transcription factor oncogenic functions.

Recent advances on the progressive mechanism and therapy in castration-resistant prostate cancer

Background

Although there have been great advances in mechanisms and therapeutic methods of prostate cancer, the mortality rate of prostate cancer remains high. The castration-resistant prostate cancer (CRPC), which develops from hormone-sensitive prostate cancer, foreshadows a more dismal outcome. Concomitant with the researches in the mechanism of CRPC and therapy for CRPC, more and more landmark progress has been made in recent years.

Methods

A number of clinical and experimental studies were reviewed to indicate the novel advancement in the progressive mechanism and therapy of CRPC.

Results

The androgen receptor (AR) is still a vital driver in the progression of CRPC, while other multiple mechanisms also contribute to this progression, such as tumor immunity, cancer stem cells, epithelial–mesenchymal transition and DNA repair disorder. In terms of the therapeutic methods of CRPC, chemotherapy with drugs, such as docetaxel, has been the first-line therapy for CRPC for many years. Besides, newer agents, which target some of the above mechanisms, show additional overall survival benefits for CRPC patients. These therapies include drugs targeting the androgen axis pathway (androgen synthesis, androgen receptor splice variants, coactivators of AR and so on), PI3K-AKT pathway, WNT pathway, DNA repair, rearrangement of ETS gene, novel chemotherapy and immunotherapy, bone metastasis therapy and so on. Understanding these novel findings on the mechanisms of CRPC and the latest potential CRPC therapies will direct us for further exploration of CRPC.

Conclusion

Through comprehensive consideration, the predominant mechanism of CRPC might be the AR signal axis concomitant with tumor microenvironment, stress, immunity, tumor microenvironment and so on. For CRPC therapy, targeting the AR axis pathway and chemotherapy are the first-line treatments at present. However, with the advancements in CRPC therapy made by the researchers, other novel potential methods will occupy more and more important position in the treatment of CRPC, especially the therapies targeting the tumor microenviroment, tumor immunity and DNA repair and so on.

Discovery and characterization of small molecules targeting the DNA-binding ETS domain of ERG in prostate cancer

Genomic alterations involving translocations of the ETS-related gene ERG occur in approximately half of prostate cancer cases. These alterations result in aberrant, androgen-regulated production of ERG protein variants that directly contribute to disease development and progression. This study describes the discovery and characterization of a new class of small molecule ERG antagonists identified through rational in silico methods. These antagonists are designed to sterically block DNA binding by the ETS domain of ERG and thereby disrupt transcriptional activity. We confirmed the direct binding of a lead compound, VPC-18005, with the ERG-ETS domain using biophysical approaches. We then demonstrated VPC-18005 reduced migration and invasion rates of ERG expressing prostate cancer cells, and reduced metastasis in a zebrafish xenograft model. These results demonstrate proof-of-principal that small molecule targeting of the ERG-ETS domain can suppress transcriptional activity and reverse transformed characteristics of prostate cancers aberrantly expressing ERG. Clinical advancement of the developed small molecule inhibitors may provide new therapeutic agents for use as alternatives to, or in combination with, current therapies for men with ERG-expressing metastatic castration-resistant prostate cancer.

Antibacterial and antiproliferative activity of novel 2-benzimidazolyl- and 2-benzothiazolyl-substituted benzo[b]thieno-2-carboxamides

Novel nitro (3a-3f)- and amino (4a-4f and 5a-5f)-substituted 2-benzimidazolyl and 2-benzothiazolyl benzo[b]thieno-2-carboxamides were designed and synthesized as potential antibacterial agents. The antibacterial activity of these compounds has been evaluated against Gram-positive (Staphylococcus aureus and Enterococcus faecalis) and Gram-negative bacteria (Escherichia coli and Moraxella catarrhalis). The most promising antibacterial activity was observed for the nitro- and amino-substituted benzimidazole derivatives 3a, 4a, 5a and 5b with MICs 2-8 [Formula: see text]. Additionally, compounds with inferior antibacterial activity were further tested for their antiproliferative activity in vitro against three human cancer cell lines. Amino-substituted benzothiazole hydrochloride salt 5d displayed the most pronounced and selective activity against the MCF-7 cell line with an [Formula: see text] of 40 nM. Furthermore, DNA binding experiments of selected derivatives indicated that DNA cannot be considered as a primary biological target for this type of compounds.

TMPRSS2-ERG fusion promotes prostate cancer metastases in bone

Bone metastasis is the major deleterious event in prostate cancer (PCa). TMPRSS2-ERG fusion is one of the most common chromosomic rearrangements in PCa. However, its implication in bone metastasis development is still unclear. Since bone metastasis starts with the tropism of cancer cells to bone through specific migratory and invasive processes involving osteomimetic capabilities, it is crucial to better our understanding of the influence of TMPRSS2-ERG expression in the mechanisms underlying the bone tropism properties of PCa cells. We developed bioluminescent cell lines expressing the TMPRSS2-ERG fusion in order to assess its role in tumor growth and bone metastasis appearance in a mouse model. First, we showed that the TMPRSS2-ERG fusion increases cell migration and subcutaneous tumor size. Second, using intracardiac injection experiments in mice, we showed that the expression of TMPRSS2-ERG fusion increases the number of metastases in bone. Moreover, TMPRSS2-ERG affects the pattern of metastatic spread by increasing the incidence of tumors in hind limbs and spine, which are two of the most frequent sites of human PCa metastases. Finally, transcriptome analysis highlighted a series of genes regulated by the fusion and involved in the metastatic process. Altogether, our work indicates that TMPRSS2-ERG increases bone tropism of PCa cells and metastasis development.

Ethnicity and ERG frequency in prostate cancer

Emerging observations emphasize a distinct biology of prostate cancer among men of different ethnicities and races, as demonstrated by remarkable differences in the frequency of ERG oncogenic activation, one of the most common and widely studied prostate cancer driver genes. Worldwide assessment of ERG alterations frequencies show consistent trends, with men of European ancestry having the highest rates of alteration and men of African or Asian ancestries having considerably lower alteration rates. However, data must be interpreted cautiously, owing to variations in assay platforms and specimen types, as well as ethnic and geographical classifications. Many opportunities and challenges remain in assessing cancer-associated molecular alterations at a global level, and these need to be addressed in order to realize the true potential of precision medicine for all cancer patients.

The oncogenic transcription factor ERG represses the transcription of the tumour suppressor gene PTEN in prostate cancer cells

The oncogene ETS-related gene (ERG) encodes a transcription factor with roles in the regulation of haematopoiesis, angiogenesis, vasculogenesis, inflammation, migration and invasion. The ERG oncogene is activated in >50% of prostate cancer cases, generally through a gene fusion with the androgen-responsive promoter of transmembrane protease serine 2. Phosphatase and tensin homologue (PTEN) is an important tumour suppressor gene that is often inactivated in cancer. ERG overexpression combined with PTEN inactivation or loss is often associated with aggressive prostate cancer. The present study aimed to determine whether or not ERG regulates PTEN transcription directly. ERG was demonstrated to bind to the PTEN promoter and repress its transcription. ERG overexpression reduced endogenous PTEN expression, whereas ERG knockdown increased PTEN expression. The ability of ERG to repress PTEN may contribute to a more cancer-permissive environment.

Therapeutic Rationale to Target Highly Expressed CDK7 Conferring Poor Outcomes in Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) patients commonly exhibit poor prognosis and high relapse after treatment, but there remains a lack of biomarkers and effective targeted therapies for this disease. Here, we report evidence highlighting the cell-cycle-related kinase CDK7 as a driver and candidate therapeutic target in TNBC. Using publicly available transcriptomic data from a collated set of TNBC patients (n = 383) and the METABRIC TNBC dataset (n = 217), we found CDK7 mRNA levels to be correlated with patient prognosis. High CDK7 protein expression was associated with poor prognosis within the RATHER TNBC cohort (n = 109) and the METABRIC TNBC cohort (n = 203). The highly specific CDK7 kinase inhibitors, BS-181 and THZ1, each downregulated CDK7-mediated phosphorylation of RNA polymerase II, indicative of transcriptional inhibition, with THZ1 exhibiting 500-fold greater potency than BS-181. Mechanistic investigations revealed that the survival of MDA-MB-231 TNBC cells relied heavily on the BCL-2/BCL-XL signaling axes in cells. Accordingly, we found that combining the BCL-2/BCL-XL inhibitors ABT-263/ABT199 with the CDK7 inhibitor THZ1 synergized in producing growth inhibition and apoptosis of human TNBC cells. Collectively, our results highlight elevated CDK7 expression as a candidate biomarker of poor prognosis in TNBC, and they offer a preclinical proof of concept for combining CDK7 and BCL-2/BCL-XL inhibitors as a mechanism-based therapeutic strategy to improve TNBC treatment. Cancer Res; 77(14); 3834-45. ©2017 AACR.

Signatures of DNA target selectivity by ETS transcription factors

The ETS family of transcription factors is a functionally heterogeneous group of gene regulators that share a structurally conserved, eponymous DNA-binding domain. DNA target specificity derives from combinatorial interactions with other proteins as well as intrinsic heterogeneity among ETS domains. Emerging evidence suggests molecular hydration as a fundamental feature that defines the intrinsic heterogeneity in DNA target selection and susceptibility to epigenetic DNA modification. This perspective invokes novel hypotheses in the regulation of ETS proteins in physiologic osmotic stress, their pioneering potential in heterochromatin, and the effects of passive and pharmacologic DNA demethylation on ETS regulation.

Crosstalk of the Androgen Receptor with Transcriptional Collaborators: Potential Therapeutic Targets for Castration-Resistant Prostate Cancer

Prostate cancer is the second leading cause of death from cancer among males in Western countries. It is also the most commonly diagnosed male cancer in Japan. The progression of prostate cancer is mainly influenced by androgens and the androgen receptor (AR). Androgen deprivation therapy is an established therapy for advanced prostate cancer; however, prostate cancers frequently develop resistance to low testosterone levels and progress to the fatal stage called castration-resistant prostate cancer (CRPC). Surprisingly, AR and the AR signaling pathway are still activated in most CRPC cases. To overcome this problem, abiraterone acetate and enzalutamide were introduced for the treatment of CRPC. Despite the impact of these drugs on prolonged survival, CRPC acquires further resistance to keep the AR pathway activated. Functional molecular studies have shown that some of the AR collaborative transcription factors (TFs), including octamer transcription factor (OCT1), GATA binding protein 2 (GATA2) and forkhead box A1 (FOXA1), still stimulate AR activity in the castration-resistant state. Therefore, elucidating the crosstalk between the AR and collaborative TFs on the AR pathway is critical for developing new strategies for the treatment of CRPC. Recently, many compounds targeting this pathway have been developed for treating CRPC. In this review, we summarize the AR signaling pathway in terms of AR collaborators and focus on pyrrole-imidazole (PI) polyamide as a candidate compound for the treatment of prostate cancer.

Copy number variation in archival melanoma biopsies versus benign melanocytic lesions

BACKGROUND

Skin melanocytes can give rise to benign and malignant neoplasms. Discrimination of an early melanoma from an unusual/atypical benign nevus can represent a significant challenge. However, previous studies have shown that in contrast to benign nevi, melanoma demonstrates pervasive chromosomal aberrations.

OBJECTIVE

This substantial difference between melanoma and benign nevi can be exploited to discriminate between melanoma and benign nevi.

METHODS

Array-comparative genomic hybridization (aCGH) is an approach that can be used on DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues to assess the entire genome for the presence of changes in DNA copy number. In this study, high resolution, genome-wide single-nucleotide polymorphism (SNP) arrays were utilized to perform comprehensive and detailed analyses of recurrent copy number aberrations in 41 melanoma samples in comparison with 21 benign nevi.

RESULTS

We found statistically significant copy number gains and losses within melanoma samples. Some of the identified aberrations are previously implicated in melanoma. Moreover, novel regions of copy number alterations were identified, revealing new candidate genes potentially involved in melanoma pathogenesis.

CONCLUSIONS

Taken together, these findings can help improve melanoma diagnosis and introduce novel melanoma therapeutic targets.

Androgen receptor profiling predicts prostate cancer outcome

Prostate cancer is the second most prevalent malignancy in men. Biomarkers for outcome prediction are urgently needed, so that high-risk patients could be monitored more closely postoperatively. To identify prognostic markers and to determine causal players in prostate cancer progression, we assessed changes in chromatin state during tumor development and progression. Based on this, we assessed genomewide androgen receptor/chromatin binding and identified a distinct androgen receptor/chromatin binding profile between primary prostate cancers and tumors with an acquired resistance to therapy. These differential androgen receptor/chromatin interactions dictated expression of a distinct gene signature with strong prognostic potential. Further refinement of the signature provided us with a concise list of nine genes that hallmark prostate cancer outcome in multiple independent validation series. In this report, we identified a novel gene expression signature for prostate cancer outcome through generation of multilevel genomic data on chromatin accessibility and transcriptional regulation and integration with publically available transcriptomic and clinical datastreams. By combining existing technologies, we propose a novel pipeline for biomarker discovery that is easily implementable in other fields of oncology.

The oncogene ERG: a key factor in prostate cancer

ETS-related gene (ERG) is a member of the E-26 transformation-specific (ETS) family of transcription factors with roles in development that include vasculogenesis, angiogenesis, haematopoiesis and bone development. ERG's oncogenic potential is well known because of its involvement in Ewing's sarcoma and leukaemia. However, in the past decade ERG has become highly associated with prostate cancer development, particularly as a result of a gene fusion with the promoter region of the androgen-induced TMPRRSS2 gene. We review ERG's structure and function, and its role in prostate cancer. We discuss potential new therapies that are based on targeting ERG.

Suppression of CHK1 by ETS Family Members Promotes DNA Damage Response Bypass and Tumorigenesis

The ETS family of transcription factors has been repeatedly implicated in tumorigenesis. In prostate cancer, ETS family members, such as ERG, ETV1, ETV4, and ETV5, are frequently overexpressed due to chromosomal translocations, but the molecular mechanisms by which they promote prostate tumorigenesis remain largely undefined. Here, we show that ETS family members, such as ERG and ETV1, directly repress the expression of the checkpoint kinase 1 (CHK1), a key DNA damage response cell-cycle regulator essential for the maintenance of genome integrity. Critically, we find that ERG expression correlates with CHK1 downregulation in human patients and demonstrate that Chk1 heterozygosity promotes the progression of high-grade prostatic intraepithelial neoplasia into prostatic invasive carcinoma in Pten(+) (/-) mice. Importantly, CHK1 downregulation sensitizes prostate tumor cells to etoposide but not to docetaxel treatment. Thus, we identify CHK1 as a key functional target of the ETS proto-oncogenic family with important therapeutic implications.

SIGNIFICANCE

Genetic translocation and aberrant expression of ETS family members is a common event in different types of human tumors. Here, we show that through the transcriptional repression of CHK1, ETS factors may favor DNA damage accumulation and consequent genetic instability in proliferating cells. Importantly, our findings provide a rationale for testing DNA replication inhibitor agents in ETS-positive TP53-proficient tumors.

Targeting molecular addictions in cancer

Cancer cells depend on a finite number of critical signals for their survival. Oncogene addiction, that is, the acquired dependence of a cancer cell on the activity of a single oncogenic gene product, has been the basis for the targeted therapy paradigm, and operationally defines such signals. Additionally, cancer cells have altered metabolic requirements that create addictions to specific nutrients such as glucose and glutamine. In this review, I will discuss the therapeutic opportunities that these two types of molecular addictions offer, focusing on lessons learned from targeting members of the epidermal growth factor receptor family of kinases, and components of MAPK pathway. I will also discuss the challenges in simultaneously harnessing two types of molecular addictions for therapeutic benefit, and the importance of understanding not only the effects of oncogenic signal transduction on metabolism, but also the impact of metabolic states on signal transduction.

Anticancer, antioxidant activities, and DNA affinity of novel monocationic bithiophenes and analogues

A series of 15 monocationic bithiophenes and isosteres were prepared and subjected to in vitro antiproliferative screening using the full National Cancer Institute (NCI)-60 cell line panel, representing nine types of cancer. Among the nine types of cancer involved in a five-dose screen, non-small cell lung and breast cancer cell lines were the most responsive to the antiproliferative effect of the tested compounds, especially cell lines A549/ATCC, NCI-H322M, and NCI-H460, whereas compounds 1a, 1c, 1d, and 7 exhibited potent activity, with GI50 values (drug concentration that causes 50% inhibition of cell growth) from less than 10 nM to 102 nM. In addition, compounds 1c and 1d gave GI50 values of 73 nM and 79 nM, respectively, against the MDA-MB-468 breast cancer cell line. Structure-activity relationship findings indicated that the mononitriles were far less active than their corresponding monoamidines and, within the amidines series, the bioisosteric replacement of a thiophene ring by a furan led to a reduction in antiproliferative activity. Also, molecular manipulations, involving substitution on the phenyl ring, or its replacement by a pyridyl, or alteration of the position of the amidine group, led to significant alteration in antiproliferative activity. On the other hand, DNA studies demonstrated that these monoamidine bichalcophenes have promising ability to cleave the genomic DNA. These monoamidines show a wide range of DNA affinities, as judged from their DNA cleavage effect, which are remarkably sensitive to all kinds of structural modifications. Finally, the novel bichalcophenes were tested for their antioxidant property by the ABTS (2,2'-azino- bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt) assay, as well as lipid and nitric oxide scavenging techniques, and were found to exhibit good-to-potent antioxidant abilities.

Recent advances in the structural molecular biology of Ets transcription factors: interactions, interfaces and inhibition

The Ets family of eukaryotic transcription factors is based around the conserved Ets DNA-binding domain. Although their DNA-binding selectivity is biochemically and structurally well characterized, structures of homodimeric and ternary complexes point to Ets domains functioning as versatile protein-interaction modules. In the present paper, we review the progress made over the last decade to elucidate the structural mechanisms involved in modulation of DNA binding and protein partner selection during dimerization. We see that Ets domains, although conserved around a core architecture, have evolved to utilize a variety of interaction surfaces and binding mechanisms, reflecting Ets domains as dynamic interfaces for both DNA and protein interaction. Furthermore, we discuss recent advances in drug development for inhibition of Ets factors, and the roles structural biology can play in their future.

Androgen receptor and gene network: Micromechanics reassemble the signaling machinery of TMPRSS2-ERG positive prostate cancer cells

Prostate cancer is a gland tumor in the male reproductive system. It is a multifaceted and genomically complex disease. Transmembrane protease, serine 2 and v-ets erythroblastosis virus E26 homolog (TMPRSS2-ERG) gene fusions are the common molecular signature of prostate cancer. Although tremendous advances have been made in unraveling various facets of TMPRSS2-ERG-positive prostate cancer, many research findings must be sequentially collected and re-interpreted. It is important to understand the activation or repression of target genes and proteins in response to various stimuli and the assembly in signal transduction in TMPRSS2-ERG fusion-positive prostate cancer cells. Accordingly, we divide this multi-component review ofprostate cancer cells into several segments: 1) The role of TMPRSS2-ERG fusion in genomic instability and methylated regulation in prostate cancer and normal cells; 2) Signal transduction cascades in TMPRSS2-ERG fusion-positive prostate cancer; 3) Overexpressed genes in TMPRSS2-ERG fusion-positive prostate cancer cells; 4) miRNA mediated regulation of the androgen receptor (AR) and its associated protein network; 5) Quantitative control of ERG in prostate cancer cells; 6) TMPRSS2-ERG encoded protein targeting; In conclusion, we provide a detailed understanding of TMPRSS2-ERG fusion related information in prostate cancer development to provide a rationale for exploring TMPRSS2-ERG fusion-mediated molecular network machinery.

A small molecule that binds and inhibits the ETV1 transcription factor oncoprotein

Members of the ETS transcription factor family have been implicated in several cancers, where they are often dysregulated by genomic derangement. ETS variant 1 (ETV1) is an ETS factor gene that undergoes chromosomal translocation in prostate cancers and Ewing sarcomas, amplification in melanomas, and lineage dysregulation in gastrointestinal stromal tumors. Pharmacologic perturbation of ETV1 would be appealing in these cancers; however, oncogenic transcription factors are often deemed "undruggable" by conventional methods. Here, we used small-molecule microarray screens to identify and characterize drug-like compounds that modulate the biologic function of ETV1. We identified the 1,3,5-triazine small molecule BRD32048 as a top candidate ETV1 perturbagen. BRD32048 binds ETV1 directly, modulating both ETV1-mediated transcriptional activity and invasion of ETV1-driven cancer cells. Moreover, BRD32048 inhibits p300-dependent acetylation of ETV1, thereby promoting its degradation. These results point to a new avenue for pharmacologic ETV1 inhibition and may inform a general means to discover small molecule perturbagens of transcription factor oncoproteins.