scholarly journals Effective Tumor Targeting by EphA2-Agonist-Biotin-Streptavidin Conjugates

Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3687
Author(s):  
Parima Udompholkul ◽  
Carlo Baggio ◽  
Luca Gambini ◽  
Yu Sun ◽  
Ming Zhao ◽  
...  

We recently reported on a potent synthetic agent, 135H11, that selectively targets the receptor tyrosine kinase, EphA2. While 135H11 possesses a relatively high binding affinity for the ligand-binding domain of EphA2 (Kd~130 nM), receptor activation in the cell required the synthesis of dimeric versions of such agent (namely 135H12). This was expected given that the natural ephrin ligands also need to be dimerized or clustered to elicit agonistic activity in cell. In the present report we investigated whether the agonistic activity of 135H11 could be enhanced by biotin conjugation followed by complex formation with streptavidin. Therefore, we measured the agonistic EphA2 activity of 135H11-biotin (147B5) at various agent/streptavidin ratios, side by side with 135H12, and a scrambled version of 147B5 in pancreatic- and breast-cancer cell lines. The (147B5)n-streptavidin complexes (when n = 2, 3, 4, but not when n = 1) induced a strong receptor degradation effect in both cell lines compared to 135H12 or the (scrambled-147B5)4-streptavidin complex as a control, indicating that multimerization of the targeting agent resulted in an increased ability to cause receptor clustering and internalization. Subsequently, we prepared an Alexa-Fluor-streptavidin conjugate to demonstrate that (147B5)4-AF-streptavidin, but not the scrambled equivalent complex, concentrates in pancreatic and breast cancers in orthotopic nude-mouse models. Hence, we conclude that these novel targeting agents, with proper derivatization with imaging reagents or chemotherapy, can be used as diagnostics, and/or to deliver chemotherapy selectively to EphA2-expressing tumors.

2019 ◽  
Vol 1 (Supplement_1) ◽  
pp. i7-i7
Author(s):  
Jiaojiao Deng ◽  
Sophia Chernikova ◽  
Wolf-Nicolas Fischer ◽  
Kerry Koller ◽  
Bernd Jandeleit ◽  
...  

Abstract Leptomeningeal metastasis (LM), a spread of cancer to the cerebrospinal fluid and meninges, is universally and rapidly fatal due to poor detection and no effective treatment. Breast cancers account for a majority of LMs from solid tumors, with triple-negative breast cancers (TNBCs) having the highest propensity to metastasize to LM. The treatment of LM is challenged by poor drug penetration into CNS and high neurotoxicity. Therefore, there is an urgent need for new modalities and targeted therapies able to overcome the limitations of current treatment options. Quadriga has discovered a novel, brain-permeant chemotherapeutic agent that is currently in development as a potential treatment for glioblastoma (GBM). The compound is active in suppressing the growth of GBM tumor cell lines implanted into the brain. Radiolabel distribution studies have shown significant tumor accumulation in intracranial brain tumors while sparing the adjacent normal brain tissue. Recently, we have demonstrated dose-dependent in vitro and in vivo anti-tumor activity with various breast cancer cell lines including the human TNBC cell line MDA-MB-231. To evaluate the in vivo antitumor activity of the compound on LM, we used the mouse model of LM based on the internal carotid injection of luciferase-expressing MDA-MB-231-BR3 cells. Once the bioluminescence signal intensity from the metastatic spread reached (0.2 - 0.5) x 106 photons/sec, mice were dosed i.p. twice a week with either 4 or 8 mg/kg for nine weeks. Tumor growth was monitored by bioluminescence. The compound was well tolerated and caused a significant delay in metastatic growth resulting in significant extension of survival. Tumors regressed completely in ~ 28 % of treated animals. Given that current treatments for LM are palliative with only few studies reporting a survival benefit, Quadriga’s new agent could be effective as a therapeutic for both primary and metastatic brain tumors such as LM. REF: https://onlinelibrary.wiley.com/doi/full/10.1002/pro6.43


Endocrinology ◽  
2000 ◽  
Vol 141 (12) ◽  
pp. 4357-4364 ◽  
Author(s):  
Jennifer L. Sanders ◽  
Naibedya Chattopadhyay ◽  
Olga Kifor ◽  
Toru Yamaguchi ◽  
Robert R. Butters ◽  
...  

Abstract Metastasis of breast cancer to bone occurs with advanced disease and produces substantial morbidity. Secretion of PTH-related peptide (PTHrP) from breast cancer cells is thought to play a key role in osteolytic metastases and is increased by transforming growth factor-β (TGFβ), which is released from resorbed bone. Elevated extracellular calcium (Cao2+) also stimulates PTHrP secretion from various normal and malignant cells, an action that could potentially be mediated by the Cao2+-sensing receptor (CaR) originally cloned from the parathyroid gland. Indeed, we previously showed that both normal breast ductal epithelial cells and primary breast cancers express the CaR. In this study we investigated whether the MCF-7 and MDA-MB-231 human breast cancer cell lines express the CaR and whether CaR agonists modulate PTHrP secretion. Northern blot analysis and RT-PCR revealed bona fide CaR transcripts, and immunocytochemistry and Western analysis with a specific anti-CaR antiserum demonstrated CaR protein expression in both breast cancer cell lines. Furthermore, elevated Cao2+ and the polycationic CaR agonists, neomycin and spermine, stimulated PTHrP secretion dose dependently, with maximal, 2.1- to 2.3-fold stimulation. In addition, pretreatment of MDA-MB-231 cells overnight with TGFβ1 (0.2, 1, or 5 ng/ml) augmented both basal and high Cao2+-stimulated PTHrP secretion. Thus, in PTHrP-secreting breast cancers metastatic to bone, the CaR could potentially participate in a vicious cycle in which PTHrP-induced bone resorption raises the levels of Cao2+ and TGFβ within the bony microenvironment, which then act in concert to evoke further PTHrP release and worsening osteolysis.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Matthew Tegowski ◽  
Cheng Fan ◽  
Albert S. Baldwin

AbstractSeveral recent publications demonstrated that DRD2-targeting antipsychotics such as thioridazine induce proliferation arrest and apoptosis in diverse cancer cell types including those derived from brain, lung, colon, and breast. While most studies show that 10–20 µM thioridazine leads to reduced proliferation or increased apoptosis, here we show that lower doses of thioridazine (1–2 µM) target the self-renewal of basal-like breast cancer cells, but not breast cancer cells of other subtypes. We also show that all breast cancer cell lines tested express DRD2 mRNA and protein, regardless of thioridazine sensitivity. Further, DRD2 stimulation with quinpirole, a DRD2 agonist, promotes self-renewal, even in cell lines in which thioridazine does not inhibit self-renewal. This suggests that DRD2 is capable of promoting self-renewal in these cell lines, but that it is not active. Further, we show that dopamine can be detected in human and mouse breast tumor samples. This observation suggests that dopamine receptors may be activated in breast cancers, and is the first time to our knowledge that dopamine has been directly detected in human breast tumors, which could inform future investigation into DRD2 as a therapeutic target for breast cancer.


2020 ◽  
Vol 22 (1) ◽  
Author(s):  
Jessica Finlay-Schultz ◽  
Britta M. Jacobsen ◽  
Duncan Riley ◽  
Kiran V. Paul ◽  
Scott Turner ◽  
...  

Abstract Background Breast cancer is a highly heterogeneous disease characterized by multiple histologic and molecular subtypes. While a myriad of breast cancer cell lines have been developed over the past 60 years, estrogen receptor alpha (ER)+ disease and some mutations associated with this subtype remain underrepresented. Here we describe six breast cancer cell lines derived from patient-derived xenografts (PDX) and their general characteristics. Methods Established breast cancer PDX were processed into cell suspensions and placed into standard 2D cell culture; six emerged into long-term passageable cell lines. Cell lines were assessed for protein expression of common luminal, basal, and mesenchymal markers, growth assessed in response to estrogens and endocrine therapies, and RNA-seq and oncogenomics testing performed to compare relative transcript levels and identify putative oncogenic drivers. Results Three cell lines express ER and two are also progesterone receptor (PR) positive; PAM50 subtyping identified one line as luminal A. One of the ER+PR+ lines harbors a D538G mutation in the gene for ER (ESR1), providing a natural model that contains this endocrine-resistant genotype. The third ER+PR−/low cell line has mucinous features, a rare histologic type of breast cancer. The three other lines are ER− and represent two basal-like and a mixed ductal/lobular breast cancer. The cell lines show varied responses to tamoxifen and fulvestrant, and three were demonstrated to regrow tumors in vivo. RNA sequencing confirms all cell lines are human and epithelial. Targeted oncogenomics testing confirmed the noted ESR1 mutation in addition to other mutations (i.e., PIK3CA, BRCA2, CCND1, NF1, TP53, MYC) and amplifications (i.e., FGFR1, FGFR3) frequently found in breast cancers. Conclusions These new generation breast cancer cell lines add to the existing repository of breast cancer models, increase the number of ER+ lines, and provide a resource that can be genetically modified for studying several important clinical breast cancer features.


1997 ◽  
Vol 17 (3) ◽  
pp. 1274-1280 ◽  
Author(s):  
Z Tang ◽  
I Treilleux ◽  
M Brown

Breast cancers lacking estrogen receptor (ER) expression have an adverse prognosis and fail to respond to endocrine therapy. We have identified a transcriptional enhancer in the human ER gene which is differentially active in ER-positive (ER+) and ER-negative (ER-) human breast cancer cell lines. Enhancer function was mapped to a 35-bp element located from -3778 to -3744 upstream of the major human ER mRNA start site, which we have termed ER-EH0 (for estrogen receptor enhancer). Gel retardation assays with ER+ and ER- cell lines identified multiple DNA-protein complexes which specifically form on this enhancer. One of these complexes could be supershifted by anti-Jun or anti-Fos antibodies, identifying it as an AP-1-containing complex. Methylation interference assays suggest binding of factors to both the AP-1 site and adjacent base pairs. Enhancer activity requires both the AP-1 site and these adjacent sequences. Mutations introduced into ER-EH0 and the recently described proximal promoter element ERF-1 in the context of the full-length promoter confirm ER-EH0 as the dominant cis-acting element involved in differential ER expression.


Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5979
Author(s):  
Diana E. Baxter ◽  
Lisa M. Allinson ◽  
Waleed S. Al Amri ◽  
James A. Poulter ◽  
Arindam Pramanik ◽  
...  

Background: poor prognosis primary breast cancers are typically treated with cytotoxic chemotherapy. However, recurrences remain relatively common even after this aggressive therapy. Comparison of matched tumours pre- and post-chemotherapy can allow identification of molecular characteristics of therapy resistance and thereby potentially aid discovery of novel predictive markers or targets for chemosensitisation. Through this comparison, we aimed to identify microRNAs associated with chemoresistance, define microRNA target genes, and assess targets as predictors of chemotherapy response. Methods: cancer cells were laser microdissected from matched breast cancer tissues pre- and post-chemotherapy from estrogen receptor positive/HER2 negative breast cancers showing partial responses to epirubicin/cyclophosphamide chemotherapy (n = 5). MicroRNA expression was profiled using qPCR arrays. MicroRNA/mRNA expression was manipulated in estrogen receptor positive/HER2 negative breast cancer cell lines (MCF7 and MDA-MB-175 cells) with mimics, inhibitors or siRNAs, and chemoresponse was assessed using MTT and colony forming survival assays. MicroRNA targets were identified by RNA-sequencing of microRNA mimic pull-downs, and comparison of these with mRNAs containing predicted microRNA binding sites. Survival correlations were tested using the METABRIC expression dataset (n = 1979). Results: miR-195 and miR-26b were consistently up-regulated after therapy, and changes in their expression in cell lines caused significant differences in chemotherapy sensitivity, in accordance with up-regulation driving resistance. SEMA6D was defined and confirmed as a target of the microRNAs. Reduced SEMA6D expression was significantly associated with chemoresistance, in accordance with SEMA6D being a down-stream effector of the microRNAs. Finally, low SEMA6D expression in breast cancers was significantly associated with poor survival after chemotherapy, but not after other therapies. Conclusions: microRNAs and their targets influence chemoresponse, allowing the identification of SEMA6D as a predictive marker for chemotherapy response that could be used to direct therapy or as a target in chemosensitisation strategies.


2021 ◽  
Author(s):  
Niantao Deng ◽  
Andre Minoche ◽  
Kate Harvey ◽  
Meng Li ◽  
Juliane Winkler ◽  
...  

Abstract Background: Breast cancer cell lines (BCCLs) and patient-derived xenografts (PDX) are the most frequently used models in breast cancer research. Despite their widespread usage, genome sequencing of these models is incomplete, with previous studies only focusing on targeted gene panels, whole exome or shallow whole genome sequencing. Deep whole genome sequencing is the most sensitive and accurate method to detect single nucleotide variants and indels, gene copy number and structural events such as gene fusions.Results: Here we describe deep whole genome sequencing (WGS) of commonly used BCCL and PDX models using the Illumina X10 platform with an average ~ 60x coverage. We identify novel genomic alterations, including point mutations and genomic rearrangements at base-pair resolution, compared to previously available sequencing data. Through integrative analysis with publicly available functional screening data, we annotate new genomic features likely to be of biological significance. CSMD1, previously identified as a tumor suppressor gene in various cancer types, including head and neck, lung and breast cancers, has been identified with deletion in 50% of our PDX models, suggesting an important role in aggressive breast cancers. Conclusions: Our WGS data provides a comprehensive genome sequencing resource of these models.


Cancers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 6377
Author(s):  
Chhanda Bose ◽  
Ashly Hindle ◽  
Jihyun Lee ◽  
Jonathan Kopel ◽  
Sahil Tonk ◽  
...  

Her2-amplified breast cancers resistant to available Her2-targeted therapeutics continue to be a challenge in breast cancer therapy. Dox is the mainstay of chemotherapy of all types of breast cancer, but its usefulness is limited by cumulative cardiotoxicity. Because oxidative stress caused by dox generates the pro-apoptotic Ω-6 PUFA metabolite 4-hydroxynonenal (4-HNE), we surmised that Ω-6 PUFAs would increase the effectiveness of dox chemotherapy. Since the mercapturic acid pathway enzyme RALBP1 (also known as RLIP76 or Rlip) that limits cellular accumulation of 4-HNE also mediates dox resistance, the combination of Ω-6 PUFAs and Rlip depletion could synergistically improve the efficacy of dox. Thus, we studied the effects of the Ω-6 PUFA arachidonic acid (AA) and Rlip knockdown on the antineoplastic activity of dox towards Her2-amplified breast cancer cell lines SK-BR-3, which is sensitive to Her2 inhibitors, and AU565, which is resistant. AA increased lipid peroxidation, 4-HNE generation, apoptosis, cellular dox concentration and dox cytotoxicity in both cell lines while sparing cultured immortalized cardiomyocyte cells. The known functions of Rlip including clathrin-dependent endocytosis and dox efflux were inhibited by AA. Our results support a model in which 4-HNE generated by AA overwhelms the capacity of Rlip to defend against apoptosis caused by dox or 4-HNE. We propose that Ω-6 PUFA supplementation could improve the efficacy of dox or Rlip inhibitors for treating Her2-amplified breast cancer.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 619-619
Author(s):  
A. H. Al-Hajj ◽  
M. V. Yezhelyev ◽  
T. Liu ◽  
R. M. O’Regan

619 Background: Conventional methods of detecting breast cancer biomarkers are hampered by a lack of adequate quantification and/or an inability to detect multiple targets on small quantities of tissue. We have previously demonstrated that estrogen receptor (ER), progesterone receptor (PR) and HER2/neu (HER2) can be detected and quantified simultaneously using antibodies (Abs) directly conjugated to nanoparticles, called quantum dots (QDs), on single breast cancer sections (ASCO 2005). We have expanded our assay to use multicolored QDs conjugated directly to Abs (QD-Abs) to detect and quantify simultaneously ER, PR, and HER2, along with 3 putative biomarkers, epidermal growth factor receptor (EGFR), mammalian target of Rapamycin (mTOR), and insulin-like growth factor receptor (IGFR), in breast cancer cell lines and human breast cancers. Methods: We used multicolored QDs directly conjugated to primary Abs to detect the 6 proteins in breast cancer cell lines (MCF-7, BT474, MDA-231) and single sections of human breast cancers. The 6 proteins were quantified using spectral separation microscopy, and compared to Western blotting. Results: We detected all 6 proteins simultaneously using QD-Abs in breast cancer cell lines and breast tumors. Using hyper-spectral imaging and wavelength-resolved spectroscopy, we separated all 6 fluorescent signals, and quantified the expression of each protein detected using QD-Abs. Quantification of the biomarkers showed good correlation with Western blotting. Conclusions: These results are proof of principle that 6 proteins can be simultaneously quantified using QD-Abs in single breast cancer sections. The use of multiplex QDs offers a novel method of determining the proteome of an individual breast cancer on single breast cancer sections. With the expanding use of targeted therapies in breast cancer, the ability to detect multiple proteins on small breast cancer specimens using QD-Abs, could allow not only the accurate selection of therapy, but a unique method of determining the activity of specific targeted agents. No significant financial relationships to disclose.


2020 ◽  
Author(s):  
Chengheng Liao ◽  
Cherise Ryan Glodowski ◽  
Cheng Fan ◽  
Juan Liu ◽  
Kevin Raynard Mott ◽  
...  

Abstract Metabolic dysregulation is one of the distinctive features in breast cancer. However, examining the metabolic features in various subtypes of breast cancer in their relationship to gene expression features in a physiologically relevant setting remains understudied. By performing metabolic profiling on triple-negative breast cancer (TNBC) and ER+ breast cancers from patients, TNBC patient-derived xenografts (PDXs), and representative breast cancer cell lines grown as tumors in vivo, we identify two distinctive groups defined by metabolites; a “Nucleotide-Enriched” group that shows high levels of pyrimidine pathway metabolites and biosynthetic enzymes, and a “Arginine Biosynthesis-Enriched” group that shows high levels of arginine biosynthesis intermediates. We reveal different metabolic enrichment profiles between cell lines grown in vitro versus in vivo, where cell lines grown in vivo more faithfually recapitulate patient tumors metabolic profiles. In addition, with integrated metabolic and gene expression profiling we identify a subset of genes that strongly correlates with the Nucleotide-Enriched metabolic profile, and which strongly predicts patient prognosis. As a proof-of-principle, when we target Nucleotide-Enriched metabolic dysregulation with a pyrimidine biosynthesis inhibitor (Brequinar), and/or a glutaminase inhibitor (CB-839), we observe therapeutic efficacy and decreased tumor growth in representative TNBC cell lines and an in vivo PDX upon combinatorial drug treatment. Our study reveals new therapeutic opportunities in breast cancer guided by a genomic biomarker, which could prove highly impactful for rapidly proliferating breast cancers specifically.


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