Blocking the ATR-SerRS-VEGFA pathway targets angiogenesis for UV-induced cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is the second most prevalent form of skin cancer, with an escalating incidence rate and a notable potential (up to 5%) for metastasis. Ultraviolet radiation (UVA and UVB) exposure is the primary risk factor for cSCC carcinogenesis, with literature suggesting ultraviolet radiation (UVR) promotes vascular endothelial growth factor A (VEGFA) expression. This study aims to investigate UVR-induced upregulation of VEGFA and explore combination therapeutic strategies. The skin squamous cell carcinoma cell line A431 was exposed to specific durations of ultraviolet radiation. The effect of emodin on ATR/SerRS/VEGFA pathway was observed. The cell masses were also transplanted subcutaneously into mice (n = 8). ATR inhibitor combined with emodin was used to observe the growth and angiogenesis of the xenografts. The results showed that UV treatment significantly enhanced the phosphorylation of SerRS and the expression level of VEGFA in A431 cells (p < 0.05). Treatment with emodin significantly inhibited this expression (p < 0.05), and the combination of emodin and ATR inhibitor further enhanced the inhibitory effect (p < 0.05). This phenomenon was further confirmed in the xenograft model, which showed that the combination of ATR inhibitor and emodin significantly inhibited the expression of VEGFA to inhibit angiogenesis (p < 0.05), thus showing an inhibitory effect on cSCC. This study innovatively reveals the molecular mechanism of UV-induced angiogenesis in cSCC and confirms SerRS as a novel target to inhibit cSCC angiogenesis and progression in vitro and in vivo studies.

Magnetic Titanium Dioxide Nanocomposites as a Recyclable SERRS Substrate for the Ultrasensitive Detection of Histidine.

A highly sensitive, selective and recyclable histidine detection method based on magnetic Fe3O4@mTiO2 (M-TiO2) nanocomposites with SERRS was developed. Mesoporous M-TiO2 nanoparticles were functionalized with 4-aminothiophenol and then coupled with histidine through an azo coupling reaction in 5 min, producing the corresponding azo compound. The strong and specific SERRS response of the azo product allowed for ultrasensitive and selective detection for histidine with an M-TiO2 device loaded with Ag NPs due to the molecular resonance effect and plasmonic effect of Ag NPs under a 532 nm excitation laser. The sensitivity was further enhanced with the magnetic enrichment of M-TiO2. The limit of detection (LOD) was as low as 8.00 × 10-12 mol/L. The M-TiO2 demonstrated applicability towards histidine determination in human urine without any sample pretreatment. Additionally, the M-TiO2 device can be recycled for 3 cycles with the photodegradation of the azo product under UV irradiation due to TiO2-assisted and plasmon-enhanced photocatalysis. In summary, a multifunctional and recyclable M-TiO2 device was synthesized based on azo coupling and SERRS spectroscopy for ultra-sensitive and specific histidine sensing. In addition, the proposed system demonstrated the potential for the multiplex determination of toxic compounds in the fields of food safety, industrial production and environmental protection, which benefit from the fingerprint property and universality of SERRS.

Determination of Benzocaine in Pharmaceutical Formulations by Indirect SERRS Assay Combined with Azo Coupling.

Coupled with an azo coupling reaction, a simple, rapid, sensitive, and effective surface-enhanced resonance Raman scattering (SERRS) detection method for benzocaine was developed. In our study, benzocaine which is used clinically as a local anesthetic was derived with p-aminothiophenol into a corresponding azo product within 5 min, resulting in a strong SERRS response with the simple addition of Ag NPs excited with a 532 nm laser. The linear correlation between SERRS intensity of dominant bands and logarithm of benzocaine concentration was investigated for quantitative determination. The method reached a limit of detection (LOD) down to 0.139 and 0.0788 µg/mL calculated with two peak intensity ratios (I1568/I2260 and I1331/I2260), which is comparable to most studies reported previously, and meanwhile had superiority in simplicity and rapidness. The quantitative measurements for pharmaceutical preparations with benzocaine were conducted without complex extraction and enrichment processes. It was indicated that the SERRS assay combined with azo derivatization reaction has implications for practical applications in more complicated systems involving biological samples, in which appropriate and simplified pretreatments were conducted to remove interfering components.

Insights into substrate promiscuity of human seryl-tRNA synthetase.

Seryl-tRNA synthetase (SerRS) attaches L-serine to the cognate serine tRNA (tRNASer) and the noncognate selenocysteine tRNA (tRNASec). The latter activity initiates the anabolic cycle of selenocysteine (Sec), proper decoding of an in-frame Sec UGA codon, and synthesis of selenoproteins across all domains of life. While the accuracy of SerRS is important for overall proteome integrity, it is its substrate promiscuity that is vital for the integrity of the selenoproteome. This raises a question as to what elements in the two tRNA species, harboring different anticodon sequences and adopting distinct folds, facilitate aminoacylation by a common aminoacyl-tRNA synthetase. We sought to answer this question by analyzing the ability of human cytosolic SerRS to bind and act on tRNASer, tRNASec, and 10 mutant and chimeric constructs in which elements of tRNASer were transposed onto tRNASec We show that human SerRS only subtly prefers tRNASer to tRNASec, and that discrimination occurs at the level of the serylation reaction. Surprisingly, the tRNA mutants predicted to adopt either the 7/5 or 8/5 fold are poor SerRS substrates. In contrast, shortening of the acceptor arm of tRNASec by a single base pair yields an improved SerRS substrate that adopts an 8/4 fold. We suggest that an optimal tertiary arrangement of structural elements within tRNASec and tRNASer dictate their utility for serylation. We also speculate that the extended acceptor-TΨC arm of tRNASec evolved as a compromise for productive binding to SerRS while remaining the major recognition element for other enzymes involved in Sec and selenoprotein synthesis.

Ultra-Stable Plasmonic Colloidal Aggregates for Accurate and Reproducible Quantitative SE(R)RS in Protein-Rich Biomedia.

Au/Ag colloids aggregated with simple salts are amongst the most commonly used substrates in surface-enhanced (resonance) Raman spectroscopy (SE(R)RS). However, salt-induced aggregation is a dynamic process, which means that SE(R)RS enhancements vary with time and that measurements therefore need to be taken at a fixed time point, normally within a short time-window of a few minutes. Here, we present an emulsion templated method which allows formation of densely-packed quasi-spherical Au/Ag colloidal aggregates. Since the particles in the product aggregates retain their weakly adsorbed charged ligands and the ionic strength remains low these charged aggregates resist further aggregation while still providing intense SE(R)RS enhancement which remains stable for days. This eliminates a major source of irreproducibility in conventional colloidal SE(R)RS measurements and paves the way for SE(R)RS analysis in complex systems, such as protein-rich bio-solutions where conventional aggregated colloids fail.

Dual-Modality Surface-Enhanced Resonance Raman Scattering and Multispectral Optoacoustic Tomography Nanoparticle Approach for Brain Tumor Delineation.

Difficulty in visualizing glioma margins intraoperatively remains a major issue in the achievement of gross total tumor resection and, thus, better clinical outcome of glioblastoma (GBM) patients. Here, the potential of a new combined optical + optoacoustic imaging method for intraoperative brain tumor delineation is investigated. A strategy using a newly developed gold nanostar synthesis method, Raman reporter chemistry, and silication method to produce dual-modality contrast agents for combined surface-enhanced resonance Raman scattering (SERRS) and multispectral optoacoustic tomography (MSOT) imaging is devised. Following intravenous injection of the SERRS-MSOT-nanostars in brain tumor bearing mice, sequential MSOT imaging is performed in vivo and followed by Raman imaging. MSOT is able to accurately depict GBMs three-dimensionally with high specificity. The MSOT signal is found to correlate well with the SERRS images. Because SERRS enables uniquely sensitive high-resolution surface detection, it could represent an ideal complementary imaging modality to MSOT, which enables real-time, deep tissue imaging in 3D. This dual-modality SERRS-MSOT-nanostar contrast agent reported here is shown to enable high precision depiction of the extent of infiltrating GBMs by Raman- and MSOT imaging in a clinically relevant murine GBM model and could pave new ways for improved image-guided resection of brain tumors.

Detection and Identification of Estrogen Based on Surface-Enhanced Resonance Raman Scattering (SERRS).

Many studies have shown that it is important to consider the harmful effects of phenolic hormones on the human body. Traditional UV detection has many limitations, so there is a need to develop new detection methods. We demonstrated a simple and rapid surface-enhanced resonance Raman scattering (SERRS) based detection method of trace amounts of phenolic estrogen. As a result of the coupling reaction, there is the formation of strong SERRS activity of azo compound. Therefore, the detection limits are as low as 0.2 × 10-4 for estrone (E1), estriol (E3), and bisphenol A (BPA). This method is universal because each SERRS fingerprint of the azo dyes a specific hormone. The use of this method is applicable for the testing of phenolic hormones through coupling reactions, and the investigation of other phenolic molecules. Therefore, this new method can be used for efficient detection.

SERS and SERRS Detection of the DNA Lesion 8-Nitroguanine: A Self-Labeling Modification.

Rapid and sensitive methods to detect DNA lesions are essential in order to understand their role in carcinogenesis and for potential diagnosis of cancers. The 8-nitroguanine DNA lesion, which is closely associated with inflammation-induced cancers, has been characterized for the first time by surface-enhanced Raman spectroscopy (SERS). This lesion has been studied as the free base, as well as part of a dinucleotide and oligodeoxynucleotides (ODNs) at 5 different excitation wavelengths in the range 785-488 nm. All nitrated samples produced distinctly different spectra from their control guanine counterparts, with nitro bands being assigned by DFT calculations. Additional resonance enhancement was observed at the shorter excitation wavelengths, these SERRS measurements allowed the detection of one nitrated guanine in over 1,300 bases. In addition, SER(R)S can be used to detect whether the unstable lesion is covalently attached to the ODN or has been released by hydrolytic depurination.

Direct observation of intermediates formed during steady-state electrocatalytic O2 reduction by iron porphyrins.

Heme/porphyrin-based electrocatalysts (both synthetic and natural) have been known to catalyze electrochemical O2, H(+), and CO2 reduction for more than five decades. So far, no direct spectroscopic investigations of intermediates formed on the electrodes during these processes have been reported; and this has limited detailed understanding of the mechanism of these catalysts, which is key to their development. Rotating disk electrochemistry coupled to resonance Raman spectroscopy is reported for iron porphyrin electrocatalysts that reduce O2 in buffered aqueous solutions. Unlike conventional single-turnover intermediate trapping experiments, these experiments probe the system while it is under steady state. A combination of oxidation and spin-state marker bands and metal ligand vibrations (identified using isotopically enriched substrates) allow in situ identification of O2-derived intermediates formed on the electrode surface. This approach, combining dynamic electrochemistry with resonance Raman spectroscopy, may be routinely used to investigate a plethora of metalloporphyrin complexes and heme enzymes used as electrocatalysts for small-molecule activation.

Au@pNIPAM SERRS Tags for Multiplex Immunophenotyping Cellular Receptors and Imaging Tumor Cells.

Detection technologies employing optically encoded particles have gained much interest toward clinical diagnostics and drug discovery, but the portfolio of available systems is still limited. The fabrication and characterization of highly stable surface-enhanced resonance Raman scattering (SERRS)-encoded colloids for the identification and imaging of proteins expressed in cells are reported. These plasmonic nanostructures are made of gold octahedra coated with poly(N-isopropylacrylamide) microgels and can be readily encoded with Raman active dyes while retaining high colloidal stability in biofluids. A layer-by-layer polyelectrolyte coating is used to seal the outer surface of the encoded particles and to provide a reactive surface for covalent conjugation with antibodies. The targeted multiplexing capabilities of the SERRS tags are demonstrated by the simultaneous detection and imaging of three tumor-associated surface biomarkers: epidermal growth factor receptor (EGFR), epithelial cell adhesion molecule (EpCAM), and homing cell adhesion molecule (CD44) by SERRS spectroscopy. The plasmonic microgels are able to discriminate tumor A431 (EGFR+/EpCAM+/CD44+) and nontumor 3T3 2.2 (EGFR-/EpCAM-/CD44+) cells while cocultured in vitro.

Magnetic titanium dioxide nanocomposites for surface-enhanced resonance Raman spectroscopic determination and degradation of toxic anilines and phenols.

Mesoporous M-TiO2 NCs, functionalized by PATP, can capture toxic anilines and phenols by azo coupling. Loading these nanodevices with Ag NPs offers the possibility for a sensitive quantitative determination of target compounds by SERRS spectroscopy, which allows multiplex detection because of the specific vibrational fingerprints. Sensitivity and selectivity can be further enhanced by concentrating the hybrid particles by an external magnet and compound-specific binding (anilines versus phenols). The bound toxic compounds can be degraded by TiO2-assisted photocatalysis after removal of the loaded hybrid particles from the sample solution with an external magnet. The degradation process can be enhanced in the presence of plasmonic Ag nanostructures.

Surfaceomics and surface-enhanced Raman spectroscopy of environmental microbes: matching cofactors with redox-active surface proteins.

Trypsin shaving is a targeted proteomic method for identifying cell-surface exposed proteins on bacterial cells. For the identification of redox-active cell-surface proteins, trypsin-shaving datasets can be matched with surface-enhanced Raman spectra of intact cells to identify the cofactors associated with the cell-surface proteins. Together, these approaches could help resolve questions about the presence of cell-surface electron transport components in environmental microorganisms, especially microbes that oxidize and reduce metals and metalloids as electron donors and acceptors.

Beyond the Visible: A Review of Ultraviolet Surface-Enhanced Raman Scattering Substrate Compositions, Morphologies, and Performance.

The first observation of ultraviolet surface-enhanced Raman scattering (UV-SERS) was 20 years ago, yet the field has seen a slower development pace than its visible and near-infrared counterparts. UV excitation for SERS offers many potential advantages. These advantages include increased scattering intensity, higher spatial resolution, resonance Raman enhancement from organic, biological, and semiconductor analytes, probing UV photoluminescence, and mitigating visible photoluminescence from analytes or substrates. One of the main challenges is the lack of readily accessible, effective, and reproducible UV-SERS substrates, with few commercial sources available. In this review, we evaluate the reported UV-SERS substrates in terms of their elemental composition, substrate morphology, and performance. We assess the best-performing substrates with regard to their enhancement factors and limits of detection in both the ultraviolet and deep ultraviolet regions. Even though aluminum nanostructures were the most reported and best-performing substrates, we also highlighted some unique UV-SERS composition and morphology substrate combinations. We address the challenges and potential opportunities in the field of UV-SERS, especially in relation to the development of commercially available, cost-effective substrates. Lastly, we discuss potential application areas for UV-SERS, including cost-effective detection of environmentally and militarily relevant analytes, in situ and operando experimentation, defect engineering, development of materials for extreme environments, and biosensing.

Immunoassay platform with surface-enhanced resonance Raman scattering for detecting trace levels of SARS-CoV-2 spike protein.

The early diagnosis of Coronavirus disease (COVID-19) requires either an accurate detection of genetic material or a sensitive detection of viral proteins. In this work, we designed an immunoassay platform for detecting trace levels of SARS-CoV-2 spike (S) protein. It is based on surface-enhanced resonance Raman scattering (SERRS) of methylene blue (MB) adsorbed onto spherical gold nanoparticles (AuNPs) and coated with a 6 nm silica shell. The latter shell in the SERRS nanoprobe prevented aggregation and permitted functionalization with SARS-CoV-2 antibodies. Specificity of the immunoassay was achieved by combining this functionalization with antibody immobilization on the cover slides that served as the platform support. Different concentrations of SARS-CoV-2 antigen could be distinguished and the lack of influence of interferents was confirmed by treating SERRS data with the multidimensional projection technique Sammon's mapping. With SERRS using a laser line at 633 nm, the lowest concentration of spike protein detected was 10 pg/mL, achieving a limit of detection (LOD) of 0.046 ng/mL (0.60 pM). This value is comparable to the lowest concentrations in the plasma of COVID-19 patients at the onset of symptoms, thus indicating that the SERRS immunoassay platform may be employed for early diagnosis.

Conformational Selectivity of Merocyanine on Nanostructured Silver Films: Surface Enhanced Resonance Raman Scattering (SERRS) and Density Functional Theoretical (DFT) Study.

In this study, detailed structural and vibrational analysis of merocyanine has been investigated using Raman, surface enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS). The Raman, SERS and SERRS studies aided by density functional theoretical (DFT) calculations clearly established the prevalence of the trans- and cis-conformers of the protonated form of merocyanine (MCH+) in solid and acetonitrile solution. The binding characteristics of merocyanine adsorbed on nanostructured silver-coated films (SCFs) were investigated using excitation-dependent SERS, concentration-dependent SERRS and DFT studies. The conformers of merocyanine involved in the surface adsorption processes were recognized. The prominent marker bands observed at 1538 (ethylenic C=C stretch) and 1133 cm-1 (pyridinium C-N stretch) in the Raman spectrum of merocyanine in acetonitrile shifted to 1540 and 1126 cm-1, respectively on the nanostructured SCFs. The shift in the marker bands is associated with either the preferential binding of selective conformer or change in resonance equilibrium between the benzenoid and quinoid forms. The excitation wavelength dependent SERS spectrum infers that in addition to the major contribution from the electromagnetic enhancement, chemical (resonance) effect leads to the amplification of the 1540 cm-1 band. The concentration-dependent SERRS study showed maximum enhancement for the nanostructured SCFs functionalized with 1 µM concentration of merocyanine, indicative of monolayer coverage. For lower concentrations of merocyanine, the SERRS signal intensity reduced without any alteration in the peak positions. The SERRS study thus, revealed sub-nanomolar (0.1 nM) sensing of merocyanine using nanostructured SCFs with the analytical enhancement factor (AEF) of ∼ 1010 for the 1126 cm-1 and 1540 cm-1 Raman bands for MC concentration of 0.1 nM. In this study, combination of SERRS and DFT have clearly established the predominance of trans-MCH+ on the nanostructured silver surface with minor contribution from cis-MCH+, which remain exclusively bound to the surface via the phenoxyl ring O atom. This conformational surface selectivity of geometrical isomers of merocyanine using nanostructured surfaces can be further explored for energy efficient and economical separation of geometrical isomers.

Visualizing surface marker expression and intratumoral heterogeneity with SERRS-NPs imaging.

Cell surface marker expression in tumors dictates the selection of therapeutics, therapy response, and survival. However, biopsies are invasive, sample only a small area of the tumor landscape and may miss significant areas of heterogeneous expression. Here, we investigated the potential of antibody-conjugated surface-enhanced resonance Raman scattering nanoparticles (SERRS-NPs) to depict and quantify high and low tumoral surface marker expression, focusing on the surface markers epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) in an intracerebral and peripheral setting with an inter- and intratumoral comparison of Raman signal intensities. Methods: ICR-Prkdc mice were injected with glioblastoma, epidermoid carcinoma, or breast tumor cell lines intracerebrally and peripherally. SERRS-NPs were functionalized with cetuximab or trastuzumab and administered via tail vein injection. Raman imaging was performed 18 hours post-injection in excised tumors and in vivo through the skull. Tumors were then fixed and processed for immunohistochemical evaluation. Results: Confirmed by MRI and immunohistochemistry for EGFR and HER2, our results demonstrate that antibody-conjugated SERRS-NPs go beyond the delineation of a tumor and offer clear and distinct Raman spectra that reflect the distribution of the targeted surface marker. The intensity of the SERRS-NP signal accurately discriminated high- versus low-expressing surface markers between tumors, and between different areas within tumors. Conclusion: Biopsies can be highly invasive procedures and provide a limited sample of molecular expression within a tumor. Our nanoparticle-based Raman imaging approach offers the potential to provide non-invasive and more comprehensive molecular imaging and an alternative to the current clinical gold standard of immunohistochemistry.

SERRS Detection on Silver Nanoparticles Supported on Acid-Treated Melamine-Resin Microspheres.

Melamine-resin microspheres were synthesized at a pH of 4.0 for 20 min and used as silver nanoparticle (AgNP) carriers for surface enhanced resonant Raman scattering (SERRS) detection. An acetic acid-treatment reaction was introduced into the fabrication of the final substrate. The SERRS performance of the substrate was effectively optimized by regulating excess formaldehyde and experimental parameters, such as acidity, number of treatments and reaction temperature in the acid-treatment reaction. Based on the SERRS detection, it was declared that a trace amount of oligomers with a certain degree of polymerization is necessary for the construction of SERRS hotspots. In addition, it is important to remove excess oligomers with reference to the synthetic reaction of the polymer materials, given the special role of oligomers and the wide application of polymer materials in SERRS detection.

Identification of N-methylaniline based on azo coupling reaction by combining TLC with SERRS.

The objective of this study was to establish a novel method for the determination of N-methylaniline (NMA) based on azo coupling reaction in infant pacifiers prepared with food contact silicone materials by combining thin layer chromatography (TLC) with surface-enhanced resonance Raman scattering (SERRS). TLC was used to separate the azo reaction products to confirm the component spot of azo compound, then the spot of azo compound mixed with silver sol on the TLC plate was qualitatively detected by SERRS. The limit of detection (LOD) of the method is as low as 0.50 ppm for NMA. The influence of sample matrix about the TLC-SERRS detection of NMA was investigated by experiment of simulated positive sample, and the NMA in infant pacifiers exposed to silica gel products was detected. The method of TLC-SERRS for the determination of NMA in infant pacifiers prepared with food contact silicone materials was established, and the real samples were detected. Compared with the methods ever reported, the method has the advantages of high sensitivity, specificity and low cost. It provides a new reference method for establishing a safety system for food contact silicone materials.

An isoflavone derivative potently inhibits the angiogenesis and progression of triple-negative breast cancer by targeting the MTA2/SerRS/VEGFA pathway.

Objective: Angiogenesis plays a vital role in tumor growth and metastasis. Here, we aimed to find novel efficient antiangiogenic molecules targeting vascular endothelial growth factor A (VEGFA ) at the transcriptional level to treat triple-negative breast cancer (TNBC). Methods: We used a cell-based seryl tRNA synthetase (SerRS) promoter-driven dual-luciferase reporter system to screen an in-house library of 384 naturally occurring small molecules and their derivatives to find candidate molecules that could upregulate the expression of SerRS, a potent transcriptional repressor of VEGFA. The levels of SerRS and VEGFA were examined by quantitative RT-PCR (qRT-PCR), western blotting, and/or ELISAs in TNBC cells after candidate molecule administration. Zebrafish, the Matrigel plug angiogenesis assay in mice, the TNBC allograft, and xenograft mouse models were used to evaluate the in vivo anti-angiogenic and anti-cancer activities. Furthermore, the potential direct targets of the candidates were identified by proteomics and biochemical studies. Results: We found the most active compound was 3-(4-methoxyphenyl) quinolin-4(1H)-one (MEQ), an isoflavone derivative. In TNBC cells, MEQ treatment resulted in increased SerRS mRNA (P < 0.001) and protein levels and downregulated VEGFA production. Both the vascular development of zebrafish and Matrigel plug angiogenesis in mice were inhibited by MEQ. MEQ also suppressed the angiogenesis in TNBC allografts and xenografts in mice, resulting in inhibited tumor growth and prolonged overall survival (P < 0.05). Finally, we found that MEQ regulated SerRS transcription by interacting with MTA2 (Metastasis Associated 1 Family Member 2). Conclusions: Our findings suggested that the MTA2/SerRS/VEGFA axis is a drug-treatable anti-angiogenic target, and MEQ is a promising anti-tumor molecule that merits further investigation for clinical applications.

Herb-sourced emodin inhibits angiogenesis of breast cancer by targeting VEGFA transcription.

Anti-angiogenesis is an important and promising strategy in cancer therapy. However, the current methods using anti-vascular endothelial growth factor A (VEGFA) antibodies or inhibitors targeting VEGFA receptors are not as efficient as expected partly due to their low efficiencies in blocking VEGFA signaling in vivo. Until now, there is still no method to effectively block VEGFA production in cancer cells from the very beginning, i.e., from the transcriptional level. Here, we aimed to find bioactive small molecules to block VEGFA transcription. Methods: We screened our natural compound pool containing 330 small molecules derived from Chinese traditional herbs for small molecules activating the expression of seryl-tRNA synthetase (SerRS), which is a newly identified potent transcriptional repressor of VEGFA, by a cell-based screening system in MDA-MB-231 cell line. The activities of the candidate molecules on regulating SerRS and VEGFA expression were first tested in breast cancer cells. We next investigated the antiangiogenic activity in vivo by testing the effects of candidate drugs on the vascular development in zebrafish and by matrigel plug angiogenesis assay in mice. We further examined the antitumor activities of candidate drugs in two triple-negative breast cancer (TNBC)-bearing mouse models. Furthermore, streptavidin-biotin affinity pull-down assay, coimmunoprecipitation assays, docking analysis and chromatin immunoprecipitation were performed to identify the direct targets of candidate drugs. Results: We identified emodin that could greatly increase SerRS expression in TNBC cells, consequently reducing VEGFA transcription. Emodin potently inhibited vascular development of zebrafish and blocked tumor angiogenesis in TNBC-bearing mice, greatly improving the survival. We also identified nuclear receptor corepressor 2 (NCOR2) to be the direct target of emodin. Once bound by emodin, NCOR2 got released from SerRS promoter, resulting in the activation of SerRS expression and eventually the suppression of VEGFA transcription. Conclusion: We discovered a herb-sourced small molecule emodin with the potential for the therapy of TNBC by targeting transcriptional regulators NCOR2 and SerRS to suppress VEGFA transcription and tumor angiogenesis.