Triple-negative Breast Adenocarcinoma Research Articles

Abstract 4573: Pre-clinical evaluation of small molecule CHK2 inhibitor, ART446, pre-IND candidate that enhances the olaparib and irinotecan

Abstract Background: Poly (ADP-ribose) polymerase (PARP) plays a pivotal role in DNA damage repair. Tumors with DNA Damage Response (DDR) defects exhibit increased susceptibility to drugs targeting PARP. The drugs induce DNA damage like Irinotecan (a Topoisomerase I inhibitor) are widely used in clinic as well. However, intrinsic resistance remains a significant obstacle, leading to frequent treatment failures. Chk2 is activated in response to these DNA damage inducing agents and hold the cell cycle. We developed pre-IND candidate ART446, with the aim of exploring its therapeutic potential in sensitizing DNA damage-targeting reagents. Results: In the radiometric HopSpot Kinase Assay, ART446 demonstrated significant inhibition of Chk2 (IC50, 9 nM). In HT-29 colon adenocarcinomas, co-treatment with SN38 and ART446 exhibited a synergistic therapeutic effect in vitro, with a subsequent in vivo tumor growth assay demonstrating a remarkable combined effect (TGI; Irinotecan, 46%; ART446, 16%; combined, 83.4%). Further extending our investigation to triple-negative breast adenocarcinoma MDA-MB-436, characterized by a BRCA1 mutation, we explored the sensitization potential of ART446 to PARP inhibitors. Strikingly, the combination therapy with a PARP inhibitor, Olaparib surpassed monotherapy outcomes, resulting in complete tumor growth inhibition (TGI: Olaparib, 73%; ART446, 20%; combined, 102%). Mechanistic insights revealed an increase in gamma H2AX levels by ART446 and a decrease in active forms of Chk2 which were activated by Olaparib affirming that Olaparib-induced Chk2 inhibition contributed to the sensitization effect. Conclusions: The pre-IND candidate ART446 exhibits promising potential in enhancing the therapeutic effects of Olaparib and Irinotecan. These findings provide a robust foundation for further clinical development, offering a strategic approach to overcome resistance in cancer treatment. Citation Format: Taegon Baik, Young Woo Kang, Ha Young Lee, Jin Whan Kim, A Hyeon Jeong, Jong Oh Kim, Woo-Young Kim. Pre-clinical evaluation of small molecule CHK2 inhibitor, ART446, pre-IND candidate that enhances the olaparib and irinotecan [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4573.

Photocleavable Visible Light-Triggered Anthraquinone-Derived Water-Soluble Block Copolymer for Peroxynitrite Generation in Cancer Therapy.

We report a facile stimuli-responsive strategy to generate reactive oxygen and nitrogen species (ROS and RNS) in the biological milieu from a photocleavable water-soluble block copolymer under visible light irradiation (427 nm, 2.25 mW/cm2). An anthraquinone-based water-soluble polymeric nitric oxide (NO) donor (BCPx-NO) is synthesized, which exhibits NO release in the range of 40-65 μM within 10 h of photoirradiation with a half-life of 30-103 min. Additionally, BCPx-NO produces peroxynitrite (ONOO-) and singlet oxygen (1O2) under photoirradiation. To understand the mechanism of NO release and photolysis of the functional group under blue light, we prepared a small-molecule anthraquinone-based N-nitrosamine (NOD). The cellular investigation of the effect of spatiotemporally controlled ONOO- and 1O2 generation from the NO donor polymeric nanoparticles in a triple negative breast adenocarcinoma (MDA-MB-231) under visible light irradiation (white light, 5.83 mW/cm2; total dose 31.5 J/cm2) showed an IC50 of 0.6 mg/mL. The stimuli-responsive strategy using a photolabile water-soluble block copolymer employed to generate ROS and RNS in a biological setting widens the horizon for their potential in cancer therapy.

Latonduine-1-Amino-Hydantoin Hybrid, Triazole-Fused Latonduine Schiff Bases and Their Metal Complexes: Synthesis, X-ray and Electron Diffraction, Molecular Docking Studies and Antiproliferative Activity

A series of latonduine derivatives, namely 11-nitro-indolo[2,3-d]benzazepine-7-(1-amino-hydantoin) (B), triazole-fused indolo[2,3-d]benzazepine-based Schiff bases HL1 and HL2 and metal complexes [M(p-cymene)(HL1)Cl]Cl, where M = Ru (1), Os (2), and [Cu(HL2)Cl2] (3) were synthesized and characterized by spectroscopic techniques (UV–vis, 1H, 13C, 15N–1H HSQC NMR) and ESI mass spectrometry. The molecular structures of B and HL1 were confirmed by single-crystal X-ray diffraction, while that of 3 by electron diffraction of nanometer size crystalline sample. Molecular docking calculations of species B in the binding pocket of PIM-1 enzyme revealed that the 1-amino-hydantoin moiety is not involved in any hydrogen-bonding interactions, even though a good accommodation of the host molecule in the ATP binding pocket of the enzyme was found. The antiproliferative activity of organic compounds B, HL1 and HL2, as well as complexes 1–3 was investigated in lung adenocarcinoma A549, colon adenocarcinoma LS-174 and triple-negative breast adenocarcinoma MDA-MB-231 cells and normal human lung fibroblast cells MRC-5 by MTT assays; then, the results are discussed.

Loss of monoacylglycerol O-acyltransferase 2 can be compensated for by diacylglycerol O-acyltransferases 1 and 2 resulting in a negligible influence on mammary cancer development found in a mouse model and verified in human tissues

Background: Dietary fat absorption involves the re-esterification of digested triacylglycerol in the enterocytes, it is a biological process catalyzed by monoacylglycerol O-acyltransferase 2 (MOGAT2, aka MGAT2), which is highly expressed in the small intestine. A previous study showed that the loss of the Mogat2 gene can prevent high-fat diet-induced obesity in mice. Obesity is associated with an increased risk of several types of cancer including a postmenopausal mammary tumor. Methods: We collected 147 patients with triple-negative breast adenocarcinoma to explore the relationship between MOGAT2 expression and overall patient survival. The TCGA data were also retrieved for analyzing the prognostic values of MOGAT2 mRNA level as well as the relationships between MOGAT2 and DGAT1/2 mRNA levels. We also used a Mogat2-deficient mouse mammary tumor model by crossing Mogat2-deficient mice with MMTV-PyMT mice to examine the effect of MOGAT2 on mammary tumor development. Results: In human triple-negative breast adenocarcinoma, elevated expression of MOGAT2 correlated with a poorer patient prognosis. Obesity could be induced by a relatively high-fat diet (37% of calories from fat) in the mice with or without Mogat2 knockout. Mammary tumor development was deteriorated by a relatively high-fat diet regardless of Mogat2 deficiency. As a compensation mechanism, upregulation of diacylglycerol O-acyltransferases 1 and 2 (Dgat1 and Dgat2) in the Mogat2 deficient mice was found. Consistently, in human normal tissues adjacent to breast cancer, an inverse correlation between MOGAT2 mRNA level and DGAT1/2 mRNA levels was also found. Conclusions: Elevated expression of MOGAT2 in triple-negative breast adenocarcinoma predicts poorer patient overall survival. With the compensation of Dgat1 and Dgat2, Mogat2 deficiency alone cannot prevent fat diet-induced obesity, nor prevent mammary tumor development in a mouse model.

Metastatic triple negative breast adenocarcinoma presenting as a fungating chest wall mass

A 60-year-old female with no previous medical history presented with progressive left sided weakness. Examination demonstrated a large, fungating chest wall mass with mucopurulent drainage and necrotic odor. The patient stated this lesion was worsening for multiple years and was associated with a 90-pound weight loss; however, she was hesitant to seek medical care until the onset of weakness. Comprehensive imaging, biopsy, and tissue analysis revealed the wound was consistent with fungating triple-negative breast adenocarcinoma with lung and frontal lobe metastasis (Figure 1).

Drug combination study of novel oxorhenium(V) complexes

Three Re(V) complexes of structural formulas [ReOCl2L(PPh3)], where L is pyridine-2-carboxylic acid (C1), 3-methyl-pyridine-2-carboxylic acid (C2) and 6-methyl-pyridine-2-carboxylic acid (C3) were synthesized and characterized using NMR, IR spectroscopy and mass spectrometry. Crystal structures of all three complexes have been additionally confirmed by X-ray analysis. The biological activity has been investigated in the panel of tumor cell lines A549, PANC-1, MDA-MB-231, MCF-7, LS-174, EAhy.926 and one in non-tumor cell line MRC-5. Only C1 showed dose-dependent cytotoxic potential, particularly toward triple-negative breast adenocarcinoma cells MDA-MB-231 with IC50 68.90 ± 1.73 μM and pancreatic adenocarcinoma cells PANC-1 with IC50 69.84 ± 2.3 μM. Both cell lines are characterized by a highly invasive and resistant phenotype. Drug combination studies in PANC-1 cells with C1 and Verapamil hydrochloride (VRP), which is the established inhibitor of efflux transporter P-glycoprotein (Pgp), revealed enhancement of antiproliferative action of the complex in a dose-dependent manner, and slight arrest of cell cycle in the S phase. Also, a depletion of the glutathione (GSH) level by L-buthionine-sulfoximine (L-BSO) at sub-toxic concentrations (100 μM) caused an increase of activity of C1 to the IC50 57.67 ± 6.51 (μM). A morphological analysis in PANC-1 cells by dual acridine orange/ethidium bromide staining, revealed apoptotic potential of complex C1 and a slower kinetic of cell death induction, suggesting a different mechanism of action compared to cisplatin.

Tracking the Evolution of Metastasis with Self-Functionalized 3D Nanoprobes.

Despite recent advances in cancer treatment, metastasis is the cause of mortality in 90% of cancer cases. It has now been well-established that dissemination of cancer cells to distant sites occurs very early during tumorigenesis, resulting in the minimal effect of surgical or chemotherapeutic treatments after the detection of metastasis. The underlying reason for this challenge is mostly due to the limited understanding of molecular mechanisms of the metastasis cascade, particularly related to metastatic traits. Therefore, there is an urgent need to investigate this currently invisible evolution of metastasis. The tracking of metastasis evolution has not been addressed yet. Here, we introduce, for the first time, a synchronous approach to unveil the molecular mechanisms of the metastasis cascade. As cancer stem cells (CSCs) demonstrate cancer initiation, drug resistance, metastasis, and tumor relapse and can exist in a quasi-intermediate epithelial-mesenchymal transition state, the tumor-initiating events during a CSCs metamorphosis were monitored with single-cell sensitivity. Because of the invasive and resistive properties of the metastable intermediate CSCs, investigation of the molecular profiles of the quasi-intermediate CSCs was necessary for the detection of metastasis dissemination. For this purpose, the ultrasensitive technique of surface-enhanced Raman scattering (SERS) was adopted. Titanium-based, biocompatible three-dimensional (3D) nanoprobes that were synthesized for multiphoton ionization achieved a substantial SERS enhancement of ∼80-fold due to the oxygen vacancy-enriched composition of the nanoprobes. The 3D interconnected complex nanoarchitecture of the nanoprobes enabled us to entrap the nonadherent CSCs of three metastatic cancer cell lines (triple negative breast adenocarcinoma (MDAMB231), human Caucasian colon adenocarcinoma (COLO 205), and cervical adenocarcinoma (HeLa)─all very aggressive forms of cancer). The nanoprobes not only promoted the CSC proliferation to successfully attain the quasi-intermediate states but also monitored its reprogramming into a cancer cell state. The nanoprobes substantially amplified weak intracellular Raman signals to capture the molecular events during a CSC transformation. The detection of cancer was achieved with 100% accuracy. We experimentally demonstrated that the molecular signatures of CSC reprogramming are cancer-type specific. This observation enabled us to identify the origin of metastasis with 100% accuracy, providing more clarity on the relatively unknown quasi-intermediate states. This first demonstration of CSC-based tracking of metastasis evolution has the potential to provide an insightful perspective of tumorigenesis that could be useful in cancer diagnosis and prognosis as well as in the monitoring of therapeutic interventions.

Determination of Cytisine and N-Methylcytisine from Selected Plant Extracts by High-Performance Liquid Chromatography and Comparison of Their Cytotoxic Activity

Quinolizidine alkaloids exhibit various forms of biological activity. A lot of them were found in the Leguminosae family, including Laburnum and Genista. The aim of the study was the optimization of a chromatographic system for the analysis of cytisine and N-methylcytisine in various plant extracts as well as an investigation of the cytotoxic activities of selected alkaloids and plant extracts obtained from Laburnum anagyroides, Laburnum anagyroides L. quercifolium, Laburnum alpinum, Laburnum watereri, Genista germanica, and Genista tinctoria against various cancer cell lines. The determination of investigated compounds was performed by High Performance Liquid Chromatography with Diode Array Detection (HPLC-DAD), while High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight–Mass Spectrometry (HPLC-QTOF-MS) was applied for the qualitative analysis of plant extracts. The retention, separation selectivity, peaks shape, and systems efficiency obtained for cytisine and N-methylcytisine in different chromatographic systems were compared. The application of columns with alkylbonded and phenyl stationary phases led to a very weak retention of cytisine and N-methylcytisine, even when the mobile phases containing only 5% of organic modifiers were used. The strongest retention was observed when hydrophilic interaction chromatography (HILIC) or especially when ion exchange chromatography (IEC) were applied. The most optimal system in terms of alkaloid retention, peak shape, and system efficiency containing an strong cation exchange (SCX) stationary phase and a mobile phase consisted of 25% acetonitrile and formic buffer at pH 4.0 was applied for investigating alkaloids analysis in plant extracts. Cytotoxic properties of the investigated plant extracts as well as cytisine and N-methylcytisine were examined using human tongue squamous carcinoma cells (SCC-25), human pharyngeal squamous carcinoma cells (FaDu), human triple-negative breast adenocarcinoma cell line (MDA-MB-231), and human breast adenocarcinoma cell line (MCF-7). The highest cytotoxic activity against FaDu, MCF-7, and MDA-MB cancer cell lines was observed after applying the Genista germanica leaves extract. In contrast, the highest cytotoxic activity against SCC-25 cell line was obtained after treating with the seed extract of Laburnum watereri. The investigated plant extracts exhibit significant cytotoxicity against the tested human cancer cell lines and seem to be promising for further research on its anticancer activity.

Protein Kinase D3 promotes the cell proliferation by activating the ERK1/c-MYC axis in breast cancer.

Breast cancer is the second leading death cause of cancer death for all women. Previous study suggested that Protein Kinase D3 (PRKD3) was involved in breast cancer progression. In addition, the protein level of PRKD3 in triple‐negative breast adenocarcinoma was higher than that in normal breast tissue. However, the oncogenic mechanisms of PRKD3 in breast cancer is not fully investigated. Multi‐omic data showed that ERK1/c‐MYC axis was identified as a major pivot in PRKD3‐mediated downstream pathways. Our study provided the evidence to support that the PRKD3/ERK1/c‐MYC pathway play an important role in breast cancer progression. We found that knocking out PRKD3 by performing CRISPR/Cas9 genome engineering technology suppressed phosphorylation of both ERK1 and c‐MYC but did not down‐regulate ERK1/2 expression or phosphorylation of ERK2. The inhibition of ERK1 and c‐MYC phosphorylation further led to the lower protein level of c‐MYC and then reduced the expression of the c‐MYC target genes in breast cancer cells. We also found that loss of PRKD3 reduced the rate of the cell proliferation in vitro and tumour growth in vivo, whereas ectopic (over)expression of PRKD3, ERK1 or c‐MYC in the PRKD3‐knockout breast cells reverse the suppression of the cell proliferation and tumour growth. Collectively, our data strongly suggested that PRKD3 likely promote the cell proliferation in the breast cancer cells by activating ERK1‐c‐MYC axis.

Inhibitory Effect of Hesperidin on the Expression of Programmed Death Ligand (PD-L1) in Breast Cancer.

Programmed death ligand 1 (PD-L1) is overexpressed in the most aggressive breast cancer subtype, triple-negative breast cancer (TNBC), assisting the eradication of antitumor immunity, and thereby enhancing the survival of the tumor. This study explored how hesperidin affects PD-L1 expression, and thereby cancer progression in breast cancer cells. We found that MDA-MB231, the triple-negative breast adenocarcinoma cancer cell line, (high aggressiveness) has higher expression, in both mRNA and protein, of PD-L1 than that of the other breast cancer cell line, MCF-7 (low aggressiveness). Hesperidin inhibited cell proliferation in MDA-MB231 cells. Additionally, high expression of PD-L1 (both mRNA and protein) in aggressive cancer cells was strongly inhibited by hesperidin through inhibition of Akt and NF-κB signaling. Moreover, hesperidin treatment, by inhibiting activation of matrix metalloproteinases such as MMP-9 and MMP-2, suppressed the metastatic phenotype and cell migration in the PD-L1 high-expressing MDA-MB231 cells. In summary, hesperidin inhibits breast cancer cell growth through the inhibition of the expression of PD-L1 via downregulation of Akt and NF-κB signaling in TNBC. Moreover, hesperidin significantly suppresses cell migration of MDA-MB231 cells. Our findings reveal fresh insights into the anticancer effects of hesperidin which might have potential clinical implications.

Comparison of Anticancer Activity and HPLC-DAD Determination of Selected Isoquinoline Alkaloids from Thalictrum foetidum, Berberis sp. and Chelidonium majus Extracts.

Background: Plants are an important origin of natural substances that the raw material for various pharmaceutical and therapeutic applications due to the presence of phytochemicals, such as alkaloids. Alkaloids, which are found in different plant species, possess numerous biological activities. Some alkaloids have strong cytotoxic effects on various cancer cells. The search for new drugs to treat various cancers is one of the most important challenges of modern scientific research. Objective: This study aimed to investigate of cytotoxic activity of extracts that were obtained from Chelidonium Majus; Berberis sp.; Thalictrum foetidum containing various alkaloids on selected cancer cell lines. The aim was also the quantification of selected alkaloids in the investigated extracts by HPLC. Methods: The analysis of alkaloids contents were performed while using HPLC in reversed phase (RP) mode using Polar RP column and mobile phase containing acetonitrile, water, and ionic liquid. The cytotoxic effect of the tested plant extracts and respective alkaloids’ standards were examined while using human pharyngeal squamous carcinoma cells (FaDu), human tongue squamous carcinoma cells (SCC-25), human breast adenocarcinoma cell line (MCF-7), and human triple-negative breast adenocarcinoma cell line (MDA-MB-231). Conclusion: All of the investigated plant extracts possess cytotoxic activity against cancer cell lines: FaDu, SCC-25, MCF-7, and MDA-MB-231. The highest cytotoxic activity against FaDu and MDA-MB-231 cells was observed for Chelidonium majus root extract, while the highest cytotoxic activity against SCC-25 and MCF-7 cells was estimated for the Thalictrum foetidum root extract. There obtained significant differences in the cytotoxic activity of extracts that were obtained from the roots and herbs of Chelidonium majus and Thalictrum foetidum. Based on these results, investigated plant extracts can be recommended for further investigations of anticancer activity.

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study.

Curcumin has been shown to exert potential antitumor activity in vitro and in vivo involved in multiple signaling pathways. However, the application of curcumin is still limited because of its poor hydrophilicity and low bio-availability. In the present study, we investigated the therapeutic effects of a novel and water soluble bis(hydroxymethyl) alkanoate curcuminoid derivative, MTH-3, on human breast adenocarcinoma MDA-MB-231 cells. This study investigated the effect of MTH-3 on cell viability, cell cycle and induction of autophagy and apoptosis in MDA-MB-231 cells. After 24-h treatment with MTH-3, a concentration-dependent decrease in MDA-MB-231 cell viability was observed, and the IC50 value was 5.37±1.22 μM. MTH-3 significantly triggered G2/M phase arrest and apoptosis in MDA-MB-231 cells. Within a 24-h treatment, MTH-3 decreased the CDK1 activity by decreasing CDK1 and cyclin B1 protein levels. MTH-3-induced apoptosis was further confirmed by morphological assessment and Annexin V/PI staining assay. Induction of apoptosis caused by MTH-3 was accompanied by an apparent increase of DR3, DR5 and FADD and, as well as a marked decrease of Bcl-2 and Bcl-xL protein expression. MTH-3 also decreased the protein levels of Ero1, PDI, PERK and calnexin, as well as increased the expression of IRE1α, CHOP and Bip that consequently led to ER stress and MDA-MB-231 cell apoptosis. In addition, MTH-3-treated cells were involved in the autophagic process and cleavage of LC3B was observed. MTH-3 enhanced the protein levels of LC3B, Atg5, Atg7, Atg12, p62 and Beclin-1 in MDA-MB-231 cells. Finally, DNA microarray was carried out to investigate the level changes of gene expression modulated by MTH-3 in MDA-MB-231 cells. Taken together, our results suggest that MTH-3 might be a novel therapeutic agent for the treatment of triple-negative breast cancer in the near future.

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study

Effect of bis(hydroxymethyl) alkanoate curcuminoid derivative MTH-3 on cell cycle arrest, apoptotic and autophagic pathway in triple-negative breast adenocarcinoma MDA-MB-231 cells: An in vitro study

Insights into the in vitro Anticancer Effects of Diruthenium-1.

The in vitro anticancer activity of the dinuclear trithiolato-bridged arene ruthenium complex diruthenium-1 (DiRu-1) was evaluated against a panel of human cancer cell lines used as in vitro models for hepatocellular carcinoma (HepG2 cells), estrogen-responsive breast adenocarcinoma (MCF-7 cells), and triple-negative breast adenocarcinoma (MDA-MB-231 cells). DiRu-1 is highly cytotoxic to these cell lines, demonstrating half-maximal inhibitory concentrations (IC50 ) in the low-nanomolar range (77±1.4 to 268.2±4.4 nm). The main molecular mechanisms responsible for the high cytotoxicity of DiRu-1 against the most responsive MCF-7 cell line (IC50 =77±1.4 nm) were investigated on the basis of the capacity of DiRu-1 to induce oxidative stress, apoptosis, and DNA damage, and to inhibit the cell cycle and proliferation. The results show that DiRu-1 triggers caspase-dependent apoptosis in MCF-7 cells on both the intrinsic and extrinsic pathways. Moreover, the Ru complex also causes necrosis, mitotic catastrophe, and autophagy. DiRu-1 increases the intracellular levels of reactive oxygen species (ROS), which play a significant role in its cytotoxicity and pro-apoptotic activity. An important mechanism of the anticancer activity of DiRu-1 appears to be the induction of DNA lesions, mainly due to apoptotic DNA fragmentation and cell-cycle arrest at the G2 /M checkpoint. These changes are correlated with the concentration of DiRu-1, the duration of the cell treatment, and the post-treatment time.

Oseltamivir phosphate monotherapy ablates tumor neovascularization, growth, and metastasis in mouse model of human triple-negative breast adenocarcinoma.

BackgroundTriple-negative breast cancers (TNBCs) lack the estrogen, progesterone, and epidermal growth factor (EGF) receptor-2 (HER2/neu) receptors. Patients with TNBC have typical high grading, more frequent relapses, and exhibit poorer outcomes or prognosis compared with the other subtypes of breast cancers. Currently, there are no targeted therapies that are effective for TNBC. Preclinical antitumor activity of oseltamivir phosphate (OP) therapy was investigated to identify its role in tumor neovascularization, growth, invasiveness, and long-term survival in a mouse model of human TNBC.MethodsLive cell sialidase, water soluble tetrazolium, WST-1 cell viability, and immunohistochemistry assays were used to evaluate sialidase activity, cell survival, and the expression levels of tumor E-cadherin, N-cadherin, and host endothelial CD31+/PECAM-1 cells in archived paraffin-embedded TNBC MDA-MB-231 tumors grown in RAGxCγ double mutant mice.ResultsOP, anti-Neu1 antibodies, and matrix metalloproteinase-9-specific inhibitor blocked Neu1 activity associated with EGF-stimulated TNBC MDA-MB-231 cells. OP treatment of MDA-MB-231 and MCF-7 cells and their long-term tamoxifen-resistant clones reproducibly and dose-dependently reduced the sialidase activity associated with EGF-stimulated live cells and the cell viability after 72 hours of incubation. Combination of 1 μM cisplatin, 5-FU, paclitaxel, gemcitabine, or tamoxifen with OP dosages ≥300 μg/mL significantly reduced cell viability at 24, 48, and 72 hours when compared to the chemodrug alone. Heterotopic xenografts of MDA-MB-231 tumors developed robust and bloody tumor vascularization in RAG2xCγ double mutant mice. OP treatment at 30 mg/kg daily intraperitoneally reduced tumor vascularization and growth rate as well as significantly reduced tumor weight and spread to the lungs compared with the untreated cohorts. OP treatment at 50 mg/kg completely ablated tumor vascularization, tumor growth and spread to the lungs, with significant long-term survival at day 180 postimplantation, tumor shrinking, and no relapses after 56 days off-drug. OP 30 mg/kg cohort tumors expressed significantly reduced levels of human N-cadherins and host CD31+ endothelial cells with concomitant significant expression of E-cadherins compared to the untreated cohorts.ConclusionOP monotherapy may be the effective treatment therapy for TNBC.