scholarly journals Continuous Inflammatory Stimulation Leads via Metabolic Plasticity to a Prometastatic Phenotype in Triple-Negative Breast Cancer Cells

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1356
Author(s):  
Dina Morein ◽  
Linor Rubinstein-Achiasaf ◽  
Hadar Brayer ◽  
Orly Dorot ◽  
Edward Pichinuk ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Cancer Progression ◽  
Triple Negative ◽  
Metabolic Phenotype ◽  
Dependent Manner ◽  
Metabolic Plasticity ◽  
Proinflammatory Mediators ◽  
Cell Dispersion ◽  
Factor Α

Chronic inflammation promotes cancer progression by affecting the tumor cells and their microenvironment. Here, we demonstrate that a continuous stimulation (~6 weeks) of triple-negative breast tumor cells (TNBC) by the proinflammatory cytokines tumor necrosis factor α (TNFα) + interleukin 1β (IL-1β) changed the expression of hundreds of genes, skewing the cells towards a proinflammatory phenotype. While not affecting stemness, the continuous TNFα + IL-1β stimulation has increased tumor cell dispersion and has induced a hybrid metabolic phenotype in TNBC cells; this phenotype was indicated by a transcription-independent elevation in glycolytic activity and by increased mitochondrial respiratory potential (OXPHOS) of TNBC cells, accompanied by elevated transcription of mitochondria-encoded OXPHOS genes and of active mitochondria area. The continuous TNFα + IL-1β stimulation has promoted in a glycolysis-dependent manner the activation of p65 (NF-kB), and the transcription and protein expression of the prometastatic and proinflammatory mediators sICAM-1, CCL2, CXCL8 and CXCL1. Moreover, when TNBC cells were stimulated continuously by TNFα + IL-1β in the presence of a glycolysis inhibitor, their conditioned media had reduced ability to recruit monocytes and neutrophils in vivo. Such inflammation-induced metabolic plasticity, which promotes prometastatic cascades in TNBC, may have important clinical implications in treatment of TNBC patients.

scholarly journals CircNR3C2 promotes HRD1-mediated tumor-suppressive effect via sponging miR-513a-3p in triple-negative breast cancer

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Ya Fan ◽  
Jia Wang ◽  
Wen Jin ◽  
Yifei Sun ◽  
Yuemei Xu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Rna Sequencing ◽  
Cancer Progression ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Proteasomal Degradation ◽  
Circular Rnas ◽  
Mesenchymal Transition

Abstract Background E3 ubiquitin ligase HRD1 (HMG-CoA reductase degradation protein 1, alias synoviolin with SYVN1 as the official gene symbol) was found downregulated and acting as a tumor suppressor in breast cancer, while the exact expression profile of HRD1 in different breast cancer subtypes remains unknown. Recent studies characterized circular RNAs (circRNAs) playing an regulatory role as miRNA sponge in tumor progression, presenting a new viewpoint for the post-transcriptional regulation of cancer-related genes. Methods Examination of the expression of HRD1 protein and mRNA was implemented using public microarray/RNA-sequencing datasets and breast cancer tissues/cell lines. Based on public RNA-sequencing results, online databases and enrichment/clustering analyses were used to predict the specific combinations of circRNA/miRNA that potentially govern HRD1 expression. Gain-of-function and rescue experiments in vitro and in vivo were executed to evaluate the suppressive effects of circNR3C2 on breast cancer progression through HRD1-mediated proteasomal degradation of Vimentin, which was identified using immunoblotting, immunoprecipitation, and in vitro ubiquitination assays. Results HRD1 is significantly underexpressed in triple-negative breast cancer (TNBC) against other subtypes and has an inverse correlation with Vimentin, inhibiting the proliferation, migration, invasion and EMT (epithelial-mesenchymal transition) process of breast cancer cells via inducing polyubiquitination-mediated proteasomal degradation of Vimentin. CircNR3C2 (hsa_circ_0071127) is also remarkably downregulated in TNBC, negatively correlated with the distant metastasis and lethality of invasive breast carcinoma. Overexpressing circNR3C2 in vitro and in vivo leads to a crucial enhancement of the tumor-suppressive effects of HRD1 through sponging miR-513a-3p. Conclusions Collectively, we elucidated a bona fide circNR3C2/miR-513a-3p/HRD1/Vimentin axis that negatively regulates the metastasis of TNBC, suggesting that circNR3C2 and HRD1 can act as potential prognostic biomarkers. Our study may facilitate the development of therapeutic agents targeting circNR3C2 and HRD1 for patients with aggressive breast cancer.

scholarly journals ATG9A Is Overexpressed in Triple Negative Breast Cancer and Its In Vitro Extinction Leads to the Inhibition of Pro-Cancer Phenotypes

Cells ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 248 ◽  
Author(s):  
Aurore Claude-Taupin ◽  
Leïla Fonderflick ◽  
Thierry Gauthier ◽  
Laura Mansi ◽  
Jean-René Pallandre ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Progression ◽  
Triple Negative Breast Cancer ◽  
Triple Negative ◽  
Cancer Cell Line ◽  
Cancer Tissue ◽  
The Future ◽  
Cancer Phenotypes

Early detection and targeted treatments have led to a significant decrease in mortality linked to breast cancer (BC), however, important issues need to be addressed in the future. One of them will be to find new triple negative breast cancer (TNBC) therapeutic strategies, since none are currently efficiently targeting this subtype of BC. Since numerous studies have reported the possibility of targeting the autophagy pathway to treat or limit cancer progression, we analyzed the expression of six autophagy genes (ATG9A, ATG9B, BECLIN1, LC3B, NIX and P62/SQSTM1) in breast cancer tissue, and compared their expression with healthy adjacent tissue. In our study, we observed an increase in ATG9A mRNA expression in TNBC samples from our breast cancer cohort. We also showed that this increase of the transcript was confirmed at the protein level on paraffin-embedded tissues. To corroborate these in vivo data, we designed shRNA- and CRISPR/Cas9-driven inhibition of ATG9A expression in the triple negative breast cancer cell line MDA-MB-436, in order to determine its role in the regulation of cancer phenotypes. We found that ATG9A inhibition led to an inhibition of in vitro cancer features, suggesting that ATG9A can be considered as a new marker of TNBC and might be considered in the future as a target to develop new specific TNBC therapies.

scholarly journals Biochemical and Anti-Triple Negative Metastatic Breast Tumor Cell Properties of Psammaplins

Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 442 ◽  
Author(s):  
Yu-Dong Zhou ◽  
Jun Li ◽  
Lin Du ◽  
Fakhri Mahdi ◽  
Thuy Le ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Breast Tumor ◽  
Triple Negative ◽  
Hdac Inhibitors ◽  
Metastatic Breast ◽  
Dependent Manner ◽  
Breast Tumor Cells ◽  
Metastatic Breast Tumor

Breast tumors reprogram their cellular metabolism, nutrient uptake, and utilization-associated biochemical processes. These processes become further transformed as genetically predisposed metastatic breast tumor cells colonize specific organs. Breast tumor cells often metastasize to the brain, bone, lung and liver. Massagué and colleagues isolated organotropic subclones and established organ-specific gene signatures associated with lung-, bone-, and brain-specific metastatic triple-negative breast cancer (TNBC) MDA-MB-231 cells. Using these genetically characterized metastatic subclones specific to lung (LM4175), bone (BoM1833), and brain (BrM-2a), we evaluated marine natural products for the ability to differentially suppress metastatic breast cancer cells in a target organ-dependent manner. Psammaplin-based histone deacetylase (HDAC) inhibitors were found to differentially inhibit HDAC activity, induce activation of hypoxia-inducible factor-1 (HIF-1), and disrupt organotropic metastatic TNBC subclone growth. Further, psammaplins distinctly suppressed the outgrowth of BoM1833 tumor spheroids in 3D-culture systems. Similar results were observed with the prototypical HDAC inhibitor trichostatin A (TSA). These organotropic tumor cell-based studies suggest the potential application of HDAC inhibitors that may yield new directions for anti-metastatic breast tumor research and drug discovery.

Synergy of nanodiamond-doxorubicin conjugates and PD-L1 blockade effectively turns tumor associated macrophages against tumor cells

2021 ◽  
Author(s):  
Huazhen Xu ◽  
Tongfei Li ◽  
Chao Wang ◽  
Yan Ma ◽  
Yan Liu ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Lung Cancer Cells ◽  
Dependent Manner ◽  
Tumor Associated Macrophages ◽  
M1 Type

Abstract Background: Tumor-associated macrophages (TAM) are the most abundant stromal cells in the tumor microenvironment. Turning the TAM against their host tumor cells is an intriguing therapeutic strategy particularly attractive for patients with immunologically “cold” tumors. This concept was mechanistically demonstrated on in vitro human and murine lung cancer cells and their corresponding TAM models through combinatorial use of nanodiamond-doxorubicin conjugates (Nano-DOX) and a PD-L1 blocking agent BMS-1. Nano-DOX are an agent previously proved to be able to stimulate tumor cells’ immunogenicity and thereby reactivate the TAM into the anti-tumor M1 phenotype. Results: Nano-DOX were first shown to stimulate the tumor cells and the TAM to release the cytokine HMGB1 which, regardless of its source, acted through the RAGE/NF-κB pathway to induce PD-L1 in the tumor cells and PD-L1/PD-1 in the TAM. Interestingly, Nano-DOX also induced NF-κB-dependent RAGE expression in the tumor cells and thus reinforced HMGB1’s action thereon. Then, BMS-1 was shown to enhance Nano-DOX-stimulated M1-type activation of TAM both by blocking Nano-DOX-induced PD-L1 in the TAM and by blocking tumor cell PD-L1 ligation with TAM PD-1. The TAM with enhanced M1-type repolarization both killed the tumor cells and suppressed their growth. BMS-1 could also potentiate Nano-DOX’s action to suppress tumor cell growth via blocking of Nano-DOX-induced PD-L1 therein. Finally, Nano-DOX and BMS-1 achieved synergistic therapeutic efficacy against in vivo tumor grafts in a TAM-dependent manner. Conclusions: PD-L1/PD-1 upregulation mediated by autocrine and paracrine activation of the HMGB1/RAGE/NF-κB signaling is a key response of lung cancer cells and their TAM to stress, which can be induced by Nano-DOX. Blockade of Nano-DOX-induced PD-L1, both in the cancer cells and the TAM, achieves enhanced activation of TAM-mediated anti-tumor response.

scholarly journals Short-term alpha- or gamma-delta-enriched tocopherol oil supplementation differentially affects the expression of proinflammatory mediators: selective impacts on characteristics of protein tyrosine nitration in vivo

2013 ◽  
Vol 3 (1) ◽  
pp. 6 ◽  
Author(s):  
Ted H. Elsasser ◽  
Stanislaw Kahl ◽  
Katie M. Lebold ◽  
Maret G. Traber ◽  
Jessica Shaffer ◽  
...  
Keyword(s):  
Plasma Concentrations ◽  
Short Term ◽  
Proinflammatory Response ◽  
E Coli ◽  
Amyloid A ◽  
Proinflammatory Mediators ◽  
Tnf Α ◽  
Factor Α ◽  
Necrosis Factor

While vitamin E has been used for decades in cattle diets, the principle form used traditionally is the synthetic α-isoform acetate or succinate and largely no data exist on the biological partitioning or functionality of the major naturally occurring γ- and δ-isoforms in cattle. Using tyrosine 3’-nitrated protein (pNT) as a biomarker of nitrosative cell stress, we sought to evaluate the effectiveness of short-term feeding supplementation of high content natural α-tocopherol (<em>α-T</em>, 96% α-isomer) compared to high content γ- and δ-enriched low α-content mixed tocopherol oils (<em>γ-T</em>, ~70% <em>γ-</em>, 20% δ-, &lt;5% α-isoform) to mitigate systemic and hepatic aspects of the proinflammatory response to endotoxin (LPS). Calves fed diets supplemented with <em>α-T</em>, <em>γ-T</em> for five days or no tocopherol supplement (<em>T0E</em>) were challenged with a low-level of LPS (0.25 μg/kg, iv, <em>E. coli </em>055:B5) sufficient to effect a liver nitration response. As fed,<em> α-T</em> or <em>γ-T</em> increased plasma and liver content of the respective tocopherols reflecting their relative abundance in the respective diets. Plasma or tissue mediators and biomarkers of the proinflammatory response [plasma concentrations of tumor necrosis factor-α (TNF-α, P&lt;0.001), nitrate+nitrite (NOx, P&lt;0.01), and serum amyloid A (SAA, P&lt;0.001)], and general liver content of pNT (P&lt;0.005) increased after LPS. LPS-mediated increases in TNF-α were not dif- ferent between diet treatments; both plasma NOx (P&lt;0.05) and generalized liver pNT (P&lt;0.03) responses were attenuated significantly in <em>α-T </em>and <em>γ-T versus T0E calves</em>. Plasma SAA was significantly decreased in γ-T calves at 24 h post-LPS relative to responses in <em>α-T</em> or <em>T0E </em>calves. The nitration of the mitochondrial proteins 24 h post-LPS was not only attenuated in <em>α-T</em> and <em>γ-T vs T0E</em>, but also the mitigating effect of <em>γ-T</em> on these specific nitration events was greater than that of <em>α-T </em>(P&lt;0.01). Results are consistent with the concept that short-term <em>α-T</em> or <em>γ-T</em> supplementation can effectively decrease proinflammatory liver pNT after LPS; some mitochondrial nitration targets may be better protected with prophylactic supplementation with γ-,δ-tocopherol enriched oil.

Differential protective effects of Bcl-xL and Bcl-2 on apoptotic liver injury in transgenic mice

1999 ◽  
Vol 277 (3) ◽  
pp. G702-G708 ◽  
Author(s):  
Alix de la Coste ◽  
Monique Fabre ◽  
Nathalie McDonell ◽  
Arlette Porteu ◽  
Helène Gilgenkrantz ◽  
...  
Keyword(s):  
Liver Injury ◽  
Transgenic Mice ◽  
Fas Ligand ◽  
Dependent Manner ◽  
Protective Effects ◽  
Tnf Α ◽  
Apoptotic Pathways ◽  
Induced Apoptosis ◽  
Factor Α

Fas ligand (CD95L) and tumor necrosis factor-α (TNF-α) are pivotal inducers of hepatocyte apoptosis. Uncontrolled activation of these two systems is involved in several forms of liver injury. Although the broad antiapoptotic action of Bcl-2 and Bcl-xL has been clearly established in various apoptotic pathways, their ability to inhibit the Fas/CD95- and TNF-α-mediated apoptotic signal has remained controversial. We have demonstrated that the expression of BCL-2 in hepatocytes protects them against Fas-induced fulminant hepatitis in transgenic mice. The present study shows that transgenic mice overexpressing[Formula: see text]in hepatocytes are also protected from Fas-induced apoptosis in a dose-dependent manner. Bcl-xL and Bcl-2 were protective without any change in the level of endogenous[Formula: see text]or Bax and inhibited hepatic caspase-3-like activity. In vivo injection of TNF-α caused massive apoptosis and death only when transcription was inhibited. Under these conditions,[Formula: see text]mice were partially protected from liver injury and death but PK-BCL-2 mice were not. A similar differential protective effect of Bcl-xL and Bcl-2 transgenes was observed when Fas/CD95 was activated and transcription blocked. These results suggest that apoptosis triggered by activation of both Fas/CD95 and TNF-α receptors is to some extent counteracted by the transcription-dependent protective effects, which are essential for the antiapoptotic activity of Bcl-2 but not of Bcl-xL. Therefore, Bcl-xL and Bcl-2 appear to have different antiapoptotic effects in the liver whose characterization could facilitate their use to prevent the uncontrolled apoptosis of hepatocytes.

scholarly journals CBMT-48. TARGETING METABOLIC REPROGRAMMING WITH NANOCURCUMIN IN GLIOBLASTOMA MULTIFORME

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi43-vi43
Author(s):  
Hamid Suhail ◽  
Rattan Ramandeep ◽  
Giri Shailendra ◽  
Ana deCarvalho ◽  
Steven Kalkanis ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Water Solubility ◽  
Curcuma Longa ◽  
Glioma Cells ◽  
Metabolic Reprogramming ◽  
Dependent Manner ◽  
Systemic Delivery ◽  
Ampk Activity

Abstract Glioblastoma (GBM) is a highly glycolytic aggressive brain tumor characterized by increased proliferation and resistance to chemotherapy and radiotherapy. AMPK has been reported as tumor suppressor and reprograms the cellular metabolic pathways and produces a metabolic checkpoint on the cell cycle though mTORC1, p53 and other modulators involved in cell proliferation, growth, survival and autophagy. The AMPK activity is diminished in gastric, breast and ovarian tumor cells by activated PI3K-AKT pathways. Cancer cells are able to reprogram their energy metabolism to compensate their high bioenergetic demands needed for their aggressive growth and survival. Curcumin exhibits pleiotropic properties and activate MAPK and leads to suppress p53, Wnt/β-catenin, SHH and PI3K-AKT signaling pathways. Curcumin or diferuloylmethane is a yellow polyphenol extracted from the rhizome of turmeric (Curcuma longa). The absorption, biodistribution, metabolism, and elimination studies of curcumin have, unfortunately, shown only poor absorption, rapid metabolism, and elimination of curcumin as major reasons for poor bioavailability of this interesting polyphenolic compound. We have engineered a curcumin-based nanoparticle (Curc-NP) which demonstrates high water solubility. Curc-NP was effectively transported into the cells by nanoparticles through endocytosis and localized around the nuclei in the cytoplasms. In vitro studies proved that the cytotoxicity of Curc-NP is more effective against U-251 cell line in a dose-dependent manner. Systemic delivery of Curc-NP led to preferentially accumulation in an orthotopic preclinical glioma model minimizing systemic toxic effect. Multicolor microscopy images of the tumor tissue showed that Curc-NP particles were internalized inside tumor cells selectively and localized within nuclei. Curc-NP demonstrated to restore the dysregulated AMPK activity in glioma cells. Curc-NP-induced AMPK activation resulted in inhibition of oncogenic signalling pathways in glioma. Curc-NP-induced metabolic reprograming in glioma cells will be examined and the in vivo therapeutic efficacy of Curc-NP in an experimental rat model of GBM will also be evaluated.

scholarly journals Atovaquone Suppresses Triple-Negative Breast Tumor Growth by Reducing Immune-Suppressive Cells

2021 ◽  
Vol 22 (10) ◽  
pp. 5150
Author(s):  
Nehal Gupta ◽  
Shreyas Gaikwad ◽  
Itishree Kaushik ◽  
Stephen E. Wright ◽  
Maciej M. Markiewski ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Cancer Progression ◽  
Breast Tumor ◽  
Triple Negative ◽  
Immune Surveillance ◽  
Suppressor Cells ◽  
Myeloid Derived Suppressor Cells ◽  
In Vivo Models ◽  
Ribosomal Protein S19

A major contributing factor in triple-negative breast cancer progression is its ability to evade immune surveillance. One mechanism for this immunosuppression is through ribosomal protein S19 (RPS19), which facilitates myeloid-derived suppressor cells (MDSCs) recruitment in tumors, which generate cytokines TGF-β and IL-10 and induce regulatory T cells (Tregs), all of which are immunosuppressive and enhance tumor progression. Hence, enhancing the immune system in breast tumors could be a strategy for anticancer therapeutics. The present study evaluated the immune response of atovaquone, an antiprotozoal drug, in three independent breast-tumor models. Our results demonstrated that oral administration of atovaquone reduced HCC1806, CI66 and 4T1 paclitaxel-resistant (4T1-PR) breast-tumor growth by 45%, 70% and 42%, respectively. MDSCs, TGF-β, IL-10 and Tregs of blood and tumors were analyzed from all of these in vivo models. Our results demonstrated that atovaquone treatment in mice bearing HCC1806 tumors reduced MDSCs from tumor and blood by 70% and 30%, respectively. We also observed a 25% reduction in tumor MDSCs in atovaquone-treated mice bearing CI66 and 4T1-PR tumors. In addition, a decrease in TGF-β and IL-10 in tumor lysates was observed in atovaquone-treated mice with a reduction in tumor Tregs. Moreover, a significant reduction in the expression of RPS19 was found in tumors treated with atovaquone.

The New CXCR4 Inhibitor MDX-1338 Exerts Anti-Tumor Activity in Multiple Myeloma

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1844-1844 ◽  
Author(s):  
Aldo M Roccaro ◽  
Antonio Sacco ◽  
Michelle Kuhne ◽  
AbdelKareem Azab ◽  
Patricia Maiso ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Bone Marrow ◽  
Tumor Cells ◽  
Mouse Models ◽  
Research Funding ◽  
Therapeutic Agents ◽  
Dependent Manner ◽  
Apoptotic Pathways ◽  
Dose Dependent

Abstract Abstract 1844 Background. We have previously shown the SDF1/CXCR4 axis plays a major role in homing and trafficking of multiple myeloma (MM) to the bone marrow (BM), and disruption of the interaction of tumor cells with the BM leads to enhanced sensitivity to therapeutic agents. We hypothesize that the novel anti-CXCR4 antibody, BMS936564/MDX-1338, may prevent the homing and adhesion of MM cells to the BM and will sensitize them to therapeutic agents. Methods. Primary MM cells (CD138+); MM cell lines (MM.1S, RPMI.8226); and primary MM bone marrow stromal cells (BMSCs) were used. Migration towards SDF-1 and BMSCs has been evaluated. Cytotoxicity and DNA synthesis were measured by MTT and thymidine uptake, respectively. Cell signaling and apoptotic pathways were studied by Western Blot. Synergism was calculated using the Chou-Talalay method. In vivo MM tumor growth was evaluated with xenograft mouse models. Results. MDX-1338 inhibited migration of MM cells toward SDF-1a and primary MM BMSCs, in a dose-dependent manner. Adhesion of primary MM cells to BMSCs was also inhibited by BMS936564/MDX-1338 in a dose-dependent manner, while also inducing cytotoxicity on primary BM-derived CD138+ cells. BMS936564/MDX-1338 targeted MM cells in the context of BM milieu by overcoming BMSC-induced proliferation of tumor cells. In addition, BMS936564/MDX-1338 synergistically enhanced bortezomib-induced cytotoxicity in MM cells. BMS936564/MDX-1338-dependent activation of apoptotic pathways in MM cells was documented, as shown by cleavage of caspase-9 and PARP. SDF-1a-induced ERK-, Akt-, and Src-phosphorilation was inhibited by BMS936564/MDX-1338 in a dose-dependent manner. Importantly, BMS936564/MDX-1338 inhibited MM cell proliferation in vivo in xenograft mouse models. Conclusion. These studies therefore show that targeting CXCR-4 in MM by using BMS936564/MDX-1338 represents a valid therapeutic strategy in this disease. Disclosures: Roccaro: Roche:. Kuhne:BMS: Employment. Pan:Bristol-Myers Squibb: Employment. Cardarelli:Bristol-Myers Squibb: Employment. Ghobrial:Noxxon: Research Funding; Bristol-Myers Squibb: Research Funding; Millennium: Research Funding; Noxxon:; Millennium:; Celegene:; Novartis:.

Preclinical efficacy of the combination of olaparib plus carboplatin with vandetanib in triple-negative breast cancer.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13579-e13579 ◽  
Author(s):  
Nandini Dey ◽  
Hui Wu ◽  
Yuliang Sun ◽  
Pradip De ◽  
Brian Leyland-Jones
Keyword(s):  
Breast Cancer ◽  
Tumor Cells ◽  
Triple Negative ◽  
Clonogenic Assay ◽  
Directed Migration ◽  
Tnbc Cell ◽  
Huvec Cells ◽  
Vascular Mimicry

e13579 Background: BRCA1-deficiency confers sensitivity to PARP1 inhibition (alone or in combination with platinum compounds) in triple-negative breast cancer (TNBC). Recent understanding of the biology of TNBC tumor cells has recognized molecular targets suitable for treatment with targeted therapeutics including cell surface RTK(s), such as EGFR. Methods: We studied the effect of combination of PARP inhibitor, (olaparib) plus carboplatin with a dual EGFR/VEGFR inhibitor, vandetanib in a TNBC model in both in vitro and in vivo settings. We tested the effects of drug combinations on (a) cell signaling marker(s) of survival/proliferation/apoptosis, (b) adhesion-dependent and clonogenic survival, and (c) different phenotypes (migration, invasion, vascular mimicry, and cord formation) using TNBC cell and HUVEC cells. The combination of PARP1 inhibition and EGFR/VEGFR inhibition was evaluated in tumor-bearing athymic mice treated with olaparib plus carboplatin and vandetanib. Results: Data showed that, (1) EC50s for vandetanib ranged from 5-15 µM, (2) vandetanib (10 µM) inhibited phosphorylation of AKT (S473 & T308), S6RP, 4EBP1 and ERK, (3) effect of olaparib on TNBC cell survival can be effectively studied in vitro by clonogenic assay, (4) TNBC cell lines exhibited higher sensitivity to vandetanib in clonogenic assay when combined with 10 µM fixed dose of olaparib, and (5) a combination of vandetanib with olaparib plus carboplatin time dependently increased caspase-3 and PARP cleavage, inhibited vascular mimicry, blocked fibronectin-directed migration, and suppressed clonogenic growth in TNBC cells.Vandetanib blocked (a) cord formation, (b) vitronectin-directed migration, and (c) HIF-1alpha accumulation and phosphorylation of proliferation markers (AKT, 4EBP1, and ERK) in HUVEC cells. Conclusions: Anti-proliferative/pro-apoptotic, and anti-migratory/invasive effects of vandetanib (alone or in combination with carboplatin plus olaparib) were observed both in tumor cells and in endothelial cells. We are currently studying in vivo the effect of combining olaparib plus carboplatin with vandetanib, in xenograft model the results of which will be presented in the meeting.

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