ABSTRACT
PURPOSE: HOXB13 is an androgen receptor (AR) coregulator specifically expressed in cells of prostatic lineage. We sought to associate circulating tumor cell (CTC) HOXB13 expression with outcomes in men with mCRPC treated with abiraterone or enzalutamide. EXPERIMENTAL DESIGN: We conducted a retrospective analysis of the multicenter prospective PROPHECY trial of mCRPC men (NCT02269982, n = 118) treated with abiraterone/enzalutamide. CTC detection and HOXB13 complementary DNA (cDNA) expression was measured using a modified Adnatest, grouping patients into 3 categories: CTC 0 (undetectable); CTC+ HOXB13 CTC low (<4 copies); or CTC+ HOXB13 CTC high. The HOXB13 threshold was determined by maximally selected rank statistics for prognostic associations with overall survival (OS) and progression-free survival (PFS). RESULTS: We included 102 men with sufficient CTC HOXB13 cDNA, identifying 25%, 31%, and 44% of patients who were CTC 0, CTC+ HOXB13 low, and CTC+ HOXB13 high, respectively. Median OS were 25.7, 27.8, and 12.1 months whereas the median PFS were 9.0, 7.7, and 3.8 months, respectively. In subgroup analysis among men with CellSearch CTCs ≥5 copies/mL and adjusting for prior abi/enza treatment and Halabi clinical risk score, the multivariate HR for HOXB13 CTC detection was 2.39 (95% CI, 1.06-5.40) for OS and 2.78 (95% CI, 1.38-5.59) for PFS, respectively. Low HOXB13 CTC detection was associated with lower CTC PSA, PSMA, AR-FL, and AR-V7 detection, and more liver/lung metastases (41% vs. 25%). CONCLUSIONS: Higher CTC HOXB13 expression is associated with AR-dependent biomarkers in CTCs and is adversely prognostic in the context of potent AR inhibition in men with mCRPC.
Subject(s)
Androstenes , Benzamides , Neoplastic Cells, Circulating , Phenylthiohydantoin , Prostatic Neoplasms, Castration-Resistant , Male , Humans , Neoplastic Cells, Circulating/pathology , Prostatic Neoplasms, Castration-Resistant/drug therapy , Prostatic Neoplasms, Castration-Resistant/genetics , Prostatic Neoplasms, Castration-Resistant/pathology , RNA , Prospective Studies , Retrospective Studies , DNA, Complementary/therapeutic use , Receptors, Androgen/genetics , Receptors, Androgen/metabolism , Nitriles/therapeutic use , Biomarkers, Tumor/genetics , Biomarkers, Tumor/therapeutic use , Homeodomain Proteins/geneticsABSTRACT
Informing parents that their child has a diagnosis of Down syndrome (DS) is a common example of the delivery of unexpected or difficult news. Expectations and life planning will change, and if detected prenatally, discussions might include the option of pregnancy termination. Medical school curricula currently include training in breaking unexpected news; however, it is difficult to teach and assess. We use the perspectives of clinicians, educators, and a medical student who is the parent of a child with DS to frame a discussion on teaching, practicing, and assessing communication of difficult news in human genetics during medical school.
Subject(s)
Students, Medical , Child , Humans , Communication , Curriculum , Physician-Patient Relations , Truth DisclosureABSTRACT
OBJECTIVE: Unruptured intracranial aneurysms (UIA) are common. For many the treatment risks outweigh their risk of subarachnoid haemorrhage and patients undergo surveillance imaging. There is little data to inform if and how to monitor UIAs resulting in widely varying practices. This study aimed to determine the current practice of unruptured UIA surveillance in the United Kingdom. METHODS: A questionnaire was designed to address the themes of surveillance protocols for UIA including when surveillance is initiated, how frequently it is performed, and when it is terminated. Additionally, how aneurysm growth is managed and how clinically meaningful growth is defined were explored. The questionnaire was distributed to members of the British Neurovascular Group using probability-based cluster and non-probability purposive sampling methods. RESULTS: Responses were received from 30 of the 30 (100.0%) adult neurosurgical units in the United Kingdom of which 27 (90.0%) routinely perform surveillance for aneurysm growth. Only four units had a unit policy. The mean patient age up to which a unit would initiate follow-up of a low-risk UIA was 65.4 ± 9.0 years. The time points at which imaging is performed varied widely. There was an even split between whether units use a fixed duration of follow-up or an age threshold for terminating surveillance. Forty percent of units will follow-up patients more than 5 years from diagnosis. The magnitude in the change in size that was felt to constitute growth ranged from 1 to 3mm. No units routinely used vessel wall imaging although 27 had access to 3T MRI capable of performing it. CONCLUSIONS: There is marked heterogeneity in surveillance practices between units in the United Kingdom. This study will help units better understand their practice relative to their peers and provide a framework forplanning further research on aneurysm growth.
Subject(s)
Intracranial Aneurysm , Subarachnoid Hemorrhage , Adult , Humans , Middle Aged , Aged , Intracranial Aneurysm/diagnostic imaging , Intracranial Aneurysm/surgery , Follow-Up Studies , Subarachnoid Hemorrhage/diagnostic imaging , Subarachnoid Hemorrhage/epidemiology , Subarachnoid Hemorrhage/surgery , United Kingdom , Surveys and QuestionnairesABSTRACT
Despite continued interest in the development of nonsteroidal estrogens and antiestrogens, there are only a few chemotypes of estrogen receptor ligands. Using targeted screening in a ligand sensing assay, we identified a phenolic thieno[2,3-d]pyrimidine with affinity for estrogen receptor α. An efficient three-step synthesis of the heterocyclic core and structure-guided optimization of the substituents resulted in a series of potent nonsteroidal estrogens. The chemical tractability of the thieno[2,3-d]pyrimidine chemotype will support the design of new estrogen receptor ligands as therapeutic hormones and antihormones.
ABSTRACT
Many patients with multiple myeloma (MM) have comorbidities and are treated with PPAR agonists. Immunomodulatory agents (IMiDs) are the cornerstones for MM therapy. Currently, little is known about how co-administration of PPAR agonists impacts lenalidomide treatment in patients with MM. Here, we determined the effects of PPAR agonists on anti-myeloma activities of lenalidomide in vitro and in a myeloma xenograft mouse model. Genetic overexpression and CRISPR/cas9 knockout experiments were performed to determine the role of CRBN in the PPAR-mediated pathway. A retrospective cohort study was performed to determine the correlation of PPAR expression with the outcomes of patients with MM. PPAR agonists down-regulated CRBN expression and reduced the anti-myeloma efficacy of lenalidomide in vitro and in vivo. Co-treatment with PPAR antagonists increased CRBN expression and improved sensitivity to lenalidomide. PPAR expression was higher in bone marrow cells of patients with newly diagnosed MM than in normal control bone marrow samples. High PPAR expression was correlated with poor clinical outcomes. Our study provides the first evidence that PPARs transcriptionally regulate CRBN and that drug-drug interactions between PPAR agonists and IMiDs may impact myeloma treatment outcomes.
Subject(s)
Multiple Myeloma , Adaptor Proteins, Signal Transducing/metabolism , Animals , Humans , Lenalidomide/pharmacology , Mice , Multiple Myeloma/drug therapy , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , Peptide Hydrolases/metabolism , Peroxisome Proliferator-Activated Receptors/metabolism , Retrospective Studies , Ubiquitin-Protein Ligases/metabolismABSTRACT
The estrogen receptor (ER/ESR1) is expressed in a majority of breast cancers and drugs that inhibit ER signaling are the cornerstone of breast cancer pharmacotherapy. Currently, aromatase inhibitors are the frontline endocrine interventions of choice although their durability in metastatic disease is limited by activating point mutations within the ligand-binding domain of ESR1 that permit ligand-independent activation of the receptor. It has been suggested that the most commonly occurring ESR1 mutations would likely compromise the clinical activity of selective estrogen receptor downregulators and selective estrogen receptor modulators (SERMs) when used as second-line therapies. It was unclear, however, how these mutations, which are likely coexpressed in cells with ERWT, may impact response to ER ligands in a clinically meaningful manner. To address this issue, we dissected the molecular mechanism(s) underlying ESR1-mutant pharmacology in models relevant to metastatic disease. These studies revealed that the response of ESR1 mutations to ligands was dictated primarily by the relative coexpression of ERWT in cells. Specifically, dysregulated pharmacology was only evident in cells in which the mutants were overexpressed relative to ligand-activated ERWT; a finding that highlights the role of allelism in determining ER-mutant pharmacology. Importantly, we demonstrated that the antagonist activity of the SERM, lasofoxifene, was not impacted by mutant status; a finding that has led to its clinical evaluation as a treatment for patients with advanced ER-positive breast cancer whose tumors harbor ESR1 mutations.
Subject(s)
Antineoplastic Agents, Hormonal/pharmacology , Breast Neoplasms/drug therapy , Estrogen Receptor alpha/genetics , Estrogen Receptor alpha/metabolism , Mutation , Selective Estrogen Receptor Modulators/pharmacology , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Humans , Ligands , Protein Binding , Tumor Cells, CulturedABSTRACT
Brain abscesses represent areas of localised infection of the brain parenchyma. Those confined to the brainstem are rare and usually fatal if untreated. Streptococcus intermedius is a common causative organism of brain abscesses and is associated with significant morbidity. We describe a case report of medullary abscess secondary to dental infection in a 68-year-old patient. The patient presented with headaches and flu-like symptoms progressing to left hemiparesis and reduced consciousness/bulbar function. The patient underwent emergency posterior fossa craniectomy and drainage with subsequent medical management with antibiotics. Prompt diagnosis, early surgical intervention and maximal therapy with antibiotics alongside extensive rehabilitation are all vital to ensure good neurological outcome. It is imperative for medical practitioners to consider the diagnosis of brain abscess in patients presenting with rapid onset neurological deterioration. Such cases require early neurological imaging with involvement of tertiary neurosurgery services.
Subject(s)
Brain Abscess/diagnosis , Streptococcal Infections/complications , Aged , Anti-Bacterial Agents/therapeutic use , Brain Abscess/etiology , Brain Abscess/pathology , Brain Abscess/therapy , Craniotomy/methods , Drainage , Humans , Magnetic Resonance Imaging , Male , Medulla Oblongata/pathology , Streptococcus intermedius/isolation & purification , Tomography, X-Ray ComputedABSTRACT
PURPOSE: The combination of targeting the CDK4/6 and estrogen receptor (ER) signaling pathways with palbociclib and fulvestrant is a proven therapeutic strategy for the treatment of ER-positive breast cancer. However, the poor physicochemical properties of fulvestrant require monthly intramuscular injections to patients, which limit the pharmacokinetic and pharmacodynamic activity of the compound. Therefore, an orally available compound that more rapidly reaches steady state may lead to a better clinical response in patients. Here, we report the identification of G1T48, a novel orally bioavailable, non-steroidal small molecule antagonist of ER. METHODS: The pharmacological effects and the antineoplastic mechanism of action of G1T48 on tumors was evaluated using human breast cancer cells (in vitro) and xenograft efficacy models (in vivo). RESULTS: G1T48 is a potent and efficacious inhibitor of estrogen-mediated transcription and proliferation in ER-positive breast cancer cells, similar to the pure antiestrogen fulvestrant. In addition, G1T48 can effectively suppress ER activity in multiple models of endocrine therapy resistance including those harboring ER mutations and growth factor activation. In vivo, G1T48 has robust antitumor activity in a model of estrogen-dependent breast cancer (MCF7) and significantly inhibited the growth of tamoxifen-resistant (TamR), long-term estrogen-deprived (LTED) and patient-derived xenograft tumors with an increased response being observed with the combination of G1T48 and the CDK4/6 inhibitor lerociclib. CONCLUSIONS: These data show that G1T48 has the potential to be an efficacious oral antineoplastic agent in ER-positive breast cancer.
Subject(s)
Antibodies, Monoclonal, Humanized/pharmacology , Breast Neoplasms/drug therapy , Cyclin-Dependent Kinase 4/antagonists & inhibitors , Cyclin-Dependent Kinase 6/antagonists & inhibitors , HIV Antibodies/pharmacology , Neoplasms, Hormone-Dependent/drug therapy , Selective Estrogen Receptor Modulators/pharmacology , Animals , Antineoplastic Combined Chemotherapy Protocols/pharmacology , Apoptosis/drug effects , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Proliferation/drug effects , Drug Resistance, Neoplasm , Estrogen Antagonists/pharmacology , Female , Humans , Mice , Neoplasms, Hormone-Dependent/metabolism , Neoplasms, Hormone-Dependent/pathology , Protein Kinase Inhibitors/pharmacology , Receptors, Estrogen/metabolism , Tamoxifen/pharmacology , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
The paper uses clinical neuropsychological testing methods and resting state functional MRI technology to investigate whether chemotherapy can cause cognitive impairment and/or changes in local brain activity in breast cancer patients. In the thesis, 21 breast cancer patients (stage â -â ¢) who had not undergone radiotherapy and adjuvant chemotherapy were confirmed by clinical surgery and pathology, with an average age of (50.14±13.12) years. Perform 6 neuropsychological tests before chemotherapy and 1 month after chemotherapy, conventional horizontal axis T2-weighted fluid attenuation inversion recovery (T2-FLAIR) sequence, plane echo imaging blood oxygen level dependent (EPI-Bold) functional sequence collection. DPARSF software package was used to analyse the low frequency amplitude (ALFF) of resting functional MRI data. The SPSS17.0 software package was used for statistical analysis. One month after the completion of chemotherapy, the Stroop word test and interference test scores, digit span back test, auditory word learning delay 5min memory scores of breast cancer patients were significantly different than those before chemotherapy. One month after chemotherapy, the brain areas with increased ALLF in breast cancer patients include: left inferior temporal gyrus, right middle temporal gyrus, left middle temporal and upper gyrus, and bilateral praecuneus. In breast cancer patients, memory, attention, executive function and processing speed are reduced in the short term after conventional chemotherapy. Chemotherapy changes the neural activity of the resting local brain areas, mainly the increased activity of the bilateral anterior cuneiform and middle temporal gyrus, which is the brain area that constitutes the default network (DMN).
ABSTRACT
PURPOSE: Fulvestrant is a selective estrogen receptor downregulator (SERD) that is approved for first- or second-line use as a single agent or in combination with cyclin dependent kinase or phosphatidylinositol 3-kinase inhibitors for the treatment of metastatic breast cancer. Fulvestrant exhibits exceptionally effective antitumor activity in preclinical models of breast cancer, a success that has been attributed to its robust SERD activity despite modest receptor downregulation in patient tumors. By modeling human exposures in animal models we probe the absolute need for SERD activity. METHODS: Three xenograft models of endocrine therapy-resistant breast cancer were used to evaluate the efficacy of fulvestrant administered in doses historically used in preclinical studies in the field or by using a dose regimen intended to model clinical exposure levels. Pharmacokinetic and pharmacodynamic analyses were conducted to evaluate plasma exposure and intratumoral ER downregulation. RESULTS: A clinically relevant 25 mg/kg dose of fulvestrant exhibited antitumor efficacy comparable to the historically used 200 mg/kg dose, but at this lower dose it did not result in robust ER downregulation. Further, the antitumor efficacy of the lower dose of fulvestrant was comparable to that observed for other oral SERDs currently in development. CONCLUSION: The use of clinically unachievable exposure levels of fulvestrant as a benchmark in preclinical development of SERDs may negatively impact the selection of those molecules that are advanced for clinical development. Further, these studies suggest that antagonist efficacy, as opposed to SERD activity, is likely to be the primary driver of clinical response.
Subject(s)
Antineoplastic Agents, Hormonal/pharmacokinetics , Breast Neoplasms/drug therapy , Estrogen Receptor Antagonists/pharmacokinetics , Fulvestrant/pharmacokinetics , Administration, Oral , Animals , Antineoplastic Agents, Hormonal/administration & dosage , Dose-Response Relationship, Drug , Estrogen Receptor Antagonists/administration & dosage , Estrogen Receptor alpha/antagonists & inhibitors , Female , Fulvestrant/administration & dosage , Mice , Xenograft Model Antitumor AssaysABSTRACT
The article Pharmacokinetic and pharmacodynamic analysis of fulvestrant in preclinical models of breast cancer to assess the importance of its estrogen receptor-α degrader activity in antitumor efficacy, written by Suzanne E. Wardell, Alexander P. Yllanes, Christina A. Chao, Yeeun Bae, Kaitlyn J. Andreano, Taylor K. Desautels, Kendall A. Heetderks, Jeremy T. Blitzer, John D. Norris, Donald P. McDonnell, was originally published electronically on the publisher's internet portal on September 27, 2019 without open access. With the author(s)' decision to opt for Open Choice the copyright of the article changed on November 16, 2019 to © The Author(s) 2019 and the article is forthwith distributed under a Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The original article has been corrected.
ABSTRACT
Notwithstanding the positive clinical impact of endocrine therapies in estrogen receptor-alpha (ERα)-positive breast cancer, de novo and acquired resistance limits the therapeutic lifespan of existing drugs. Taking the position that resistance is nearly inevitable, we undertook a study to identify and exploit targetable vulnerabilities that were manifest in endocrine therapy-resistant disease. Using cellular and mouse models of endocrine therapy-sensitive and endocrine therapy-resistant breast cancer, together with contemporary discovery platforms, we identified a targetable pathway that is composed of the transcription factors FOXA1 and GRHL2, a coregulated target gene, the membrane receptor LYPD3, and the LYPD3 ligand, AGR2. Inhibition of the activity of this pathway using blocking antibodies directed against LYPD3 or AGR2 inhibits the growth of endocrine therapy-resistant tumors in mice, providing the rationale for near-term clinical development of humanized antibodies directed against these proteins.
Subject(s)
Hepatocyte Nuclear Factor 3-alpha/metabolism , Mammary Neoplasms, Experimental/metabolism , Transcription Factors/metabolism , Animals , Antibodies, Neutralizing/immunology , Antibodies, Neutralizing/therapeutic use , Cell Adhesion Molecules/immunology , Cell Adhesion Molecules/metabolism , Drug Resistance, Neoplasm , Estrogen Receptor alpha/genetics , Female , GPI-Linked Proteins/immunology , GPI-Linked Proteins/metabolism , Humans , MCF-7 Cells , Mammary Neoplasms, Experimental/drug therapy , Mammary Neoplasms, Experimental/genetics , Mice , Mucoproteins/immunology , Mucoproteins/metabolism , Oncogene Proteins/immunology , Oncogene Proteins/metabolismABSTRACT
Importance: Extracranial carotid and vertebral artery dissection is an important cause of stroke, particularly in younger individuals. In some but not all observational studies, it has been associated with a high risk of recurrent stroke. Both antiplatelet agents (APs) and anticoagulants (ACs) are used to reduce stroke risk, but whether 1 treatment strategy is more effective is unknown. Objective: To determine whether AP or AC therapy is more effective in preventing stroke in cervical dissection and the risk of recurrent stroke in a randomized clinical trial setting. A secondary outcome was to determine the effect on arterial imaging outcomes. Design, Setting, and Participants: Randomized, prospective, open-label international multicenter parallel design study with central blinded review of both clinical and imaging end points. Recruitment was conducted in 39 stroke and neurology secondary care centers in the United Kingdom and 7 centers in Australia between February 24, 2006, and June 17, 2013. One-year follow-up and analysis was conducted in 2018. Two hundred fifty participants with extracranial carotid and vertebral dissection with symptom onset within the last 7 days were recruited. Follow-up data at 1 year were available for all participants. Interventions: Randomization to AP or AC (heparin followed by warfarin) for 3 months, after which the choice of AP and AC agents was decided by the local clinician. Main Outcomes and Measures: The primary end point was ipsilateral stroke and death. A planned per protocol (PP) analysis was performed in patients meeting the inclusion criteria following central review of imaging to confirm the diagnosis of dissection. A secondary end point was angiographic recanalization in those with imaging confirmed dissection. Results: Two hundred fifty patients were randomized (118 carotid and 132 vertebral), 126 to AP and 124 to AC. Mean (SD) age was 49 (12) years. Mean (SD) time to randomization was 3.65 (1.91) days. The recurrent stroke rate at 1 year was 6 of 250 (2.4%) on ITT analysis and 5 of 197 (2.5%) on PP analysis. There were no significant differences between treatment groups for any outcome. Of the 181 patients with confirmed dissection and complete imaging at baseline and 3 months, there was no difference in the presence of residual narrowing or occlusion between those receiving AP (n = 56 of 92) vs those receiving AC (n = 53 of 89) (P = .97). Conclusions and Relevance: During 12 months of follow-up, the number of recurrent strokes was low. There was no difference between treatment groups in outcome events or the rate of recanalization. Trial Registration: ISRCTN.com Identifier: CTN44555237.
Subject(s)
Anticoagulants/therapeutic use , Carotid Artery, Internal, Dissection/complications , Platelet Aggregation Inhibitors/therapeutic use , Stroke/drug therapy , Vertebral Artery Dissection/complications , Adolescent , Adult , Aged , Aged, 80 and over , Aspirin/therapeutic use , Carotid Artery, Internal, Dissection/diagnostic imaging , Clopidogrel/therapeutic use , Dipyridamole/therapeutic use , Female , Hemorrhage/epidemiology , Heparin/therapeutic use , Humans , Male , Middle Aged , Mortality , Recurrence , Secondary Prevention/methods , Stroke/etiology , Treatment Outcome , Vertebral Artery Dissection/diagnostic imaging , Warfarin/therapeutic use , Young AdultABSTRACT
A drug used in hormone replacement therapy can target estrogen receptors that have become resistant to breast cancer treatments.
Subject(s)
Mutant Proteins/metabolism , Receptors, Estrogen/genetics , Breast Neoplasms/drug therapy , Breast Neoplasms/genetics , Female , Humans , Mutation/genetics , Selective Estrogen Receptor Modulators/pharmacology , Selective Estrogen Receptor Modulators/therapeutic useABSTRACT
BACKGROUND AND AIMS: Germplasm with diverse, agronomically relevant traits forms the foundation of a successful plant breeding programme. Since 1993, the United Nations has been advocating the implementation of the Convention on Biological Diversity (CBD) and the subsequent 2002 Bonn Guidelines as international best practice on germplasm collection and use. In 2006, a European team made an expedition to Asia to collect wild germplasm of Miscanthus, a C4 perennial rhizomatous grass, for breeding an environmentally adaptable, resilient and high-yielding bioenergy crop. We outline general aspects of germplasm collection, conservation, breeding and biomass production evaluation while following the CBD's guidelines, respecting biodiversity and conservation needs, and the ethical use of genetic resources. METHODS: Effective protocols, quarantine, methods for collecting seed and rhizomes, and a genebank for conservation were established. Versatile informatics and database architecture were used to assist in selection, flowering synchronization, crossing, evaluation, phenotyping and data integration. Approaches were formulated to comply with the CBD guidelines. KEY RESULTS: A total of 303 accessions of M. sinensis, M. sacchariflorus and M. floridulus were collected from 158 geographically and environmentally diverse locations. These species were shown to accumulate different amounts of aerial biomass due to combinations of stem count, height and thickness. Progeny from one interspecies cross accumulated more biomass in early trials and has shown double the yield performance in years 3-4 compared with the existing commercial cultivar M. × giganteus. An example of an F1 hybrid has already demonstrated the long-term potential of exploiting this collection for a breeding programme. CONCLUSIONS: By conforming to the CBD principles, the authors' international collaboration provides a practical example of implementing the CBD. The collection widened the genetic diversity of Miscanthus available to allow for breeding of novel hybrids that exhibit more diverse traits to increase yield and resilience for growth on marginal land and in climate-challenged environments.
Subject(s)
Biodiversity , Poaceae , Asia , Europe , United NationsABSTRACT
BACKGROUND: The recurrent p.Gly84Glu germline mutation (G84E) in HOXB13 is consistently associated with prostate cancer (PCa), although the mechanisms underlying such linkage remain elusive. The majority of the PCa-associated HOXB13 mutations identified are localized to two conserved domains in HOXB13 that have been shown to mediate the interaction with MEIS cofactors belonging to the TALE family of homeodomain transcription factors. In this study, we sought to interrogate the biochemical and functional interactions between HOXB13 and MEIS in prostatic cells with a goal of defining how the HOXB13-MEIS complex impacts PCa pathobiology and define the extent to which the oncogenic activity of G84E is related to its effect on HOXB13-MEIS interaction/function. METHODS: HOXB13 and MEIS paralog expression in prostate epithelial cells and PCa cell lines was characterized by qPCR and immunoblot analyses. HOXB13 and MEIS1 co-expression in human prostate tissue was confirmed by IHC, followed by co-IP mapping of HOXB13-MEIS1 interactions. Proliferation of the PCa cell line LAPC4 following shRNA-mediated knockdown of each gene or both genes was assessed using DNA- and metabolic-based assays. Transcriptional targets of HOXB13 and MEIS1 were identified by gene expression profiling and qPCR. Finally, protein stability of HOXB13 in the context of MEIS1 was determined using pulse-chase assays. RESULTS: HOXB13 and MEIS1 are co-expressed and interact in prostate cells. Both of the putative MEIS interacting domains (MID) within HOXB13 were shown to be capable of mediating the interaction between HOXB13 and MEIS1 independently and such interactions were not influenced by the G84E mutation. The inhibitory effect of either HOXB13 or MEIS1 knockdown on cellular proliferation was augmented by knockdown of both genes, and MEIS1 knockdown abolished HOXB13-driven regulation of BCHE and TNFSF10 mRNA expression. Notably, we demonstrated that MEIS1 stabilized the HOXB13 protein in LAPC4 cells. CONCLUSIONS: Our study provides evidence for functional HOXB13-MEIS1 interactions in PCa. MEIS1 may contribute to the cancer-promoting actions of HOXB13 in cellular proliferation and gene regulation by prolonging HOXB13 half-life. Our data demonstrates that G84E is not a loss-of-function mutation that interferes with HOXB13 stability or ability to interact with MEIS1.
Subject(s)
Homeodomain Proteins/metabolism , Myeloid Ecotropic Viral Integration Site 1 Protein/metabolism , Prostatic Neoplasms/genetics , Prostatic Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation , Gene Expression , Gene Expression Profiling , Gene Knockdown Techniques , Germ-Line Mutation , Homeodomain Proteins/genetics , Humans , Male , Myeloid Ecotropic Viral Integration Site 1 Protein/genetics , RNA, Messenger/analysisABSTRACT
Mutations in estrogen receptor alpha (ERα) that confer resistance to existing classes of endocrine therapies are detected in up to 30% of patients who have relapsed during endocrine treatments. Because a significant proportion of therapy-resistant breast cancer metastases continue to be dependent on ERα signaling, there remains a critical need to develop the next generation of ERα antagonists that can overcome aberrant ERα activity. Through our drug-discovery efforts, we identified H3B-5942, which covalently inactivates both wild-type and mutant ERα by targeting Cys530 and enforcing a unique antagonist conformation. H3B-5942 belongs to a class of ERα antagonists referred to as selective estrogen receptor covalent antagonists (SERCA). In vitro comparisons of H3B-5942 with standard-of-care (SoC) and experimental agents confirmed increased antagonist activity across a panel of ERαWT and ERαMUT cell lines. In vivo, H3B-5942 demonstrated significant single-agent antitumor activity in xenograft models representing ERαWT and ERαY537S breast cancer that was superior to fulvestrant. Lastly, H3B-5942 potency can be further improved in combination with CDK4/6 or mTOR inhibitors in both ERαWT and ERαMUT cell lines and/or tumor models. In summary, H3B-5942 belongs to a class of orally available ERα covalent antagonists with an improved profile over SoCs.Significance: Nearly 30% of endocrine therapy-resistant breast cancer metastases harbor constitutively activating mutations in ERα. SERCA H3B-5942 engages C530 of both ERαWT and ERαMUT, promotes a unique antagonist conformation, and demonstrates improved in vitro and in vivo activity over SoC agents. Importantly, single-agent efficacy can be further enhanced by combining with CDK4/6 or mTOR inhibitors. Cancer Discov; 8(9); 1176-93. ©2018 AACR.This article is highlighted in the In This Issue feature, p. 1047.
Subject(s)
Breast Neoplasms/drug therapy , Drug Resistance, Neoplasm/drug effects , Estrogen Receptor Antagonists/administration & dosage , Estrogen Receptor alpha/antagonists & inhibitors , Indazoles/administration & dosage , Mutation , Administration, Oral , Animals , Breast Neoplasms/genetics , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Cysteine/antagonists & inhibitors , Drug Screening Assays, Antitumor , Drug Synergism , Estrogen Receptor Antagonists/chemistry , Estrogen Receptor Antagonists/pharmacology , Estrogen Receptor alpha/chemistry , Estrogen Receptor alpha/genetics , Female , Humans , Indazoles/chemistry , Indazoles/pharmacology , MCF-7 Cells , Mice , Protein Conformation/drug effects , Protein Kinase Inhibitors/administration & dosage , Protein Kinase Inhibitors/pharmacology , Xenograft Model Antitumor AssaysABSTRACT
In breast cancer, estrogen receptor alpha (ERα) positive cancer accounts for approximately 74% of all diagnoses, and in these settings, it is a primary driver of cell proliferation. Treatment of ERα positive breast cancer has long relied on endocrine therapies such as selective estrogen receptor modulators, aromatase inhibitors, and selective estrogen receptor degraders (SERDs). The steroid-based anti-estrogen fulvestrant (5), the only approved SERD, is effective in patients who have not previously been treated with endocrine therapy as well as in patients who have progressed after receiving other endocrine therapies. Its efficacy, however, may be limited due to its poor physicochemical properties. We describe the design and synthesis of a series of potent benzothiophene-containing compounds that exhibit oral bioavailability and preclinical activity as SERDs. This article culminates in the identification of LSZ102 (10), a compound in clinical development for the treatment of ERα positive breast cancer.
Subject(s)
Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Estrogen Receptor alpha/drug effects , Selective Estrogen Receptor Modulators/chemical synthesis , Selective Estrogen Receptor Modulators/pharmacology , Thiophenes/chemical synthesis , Thiophenes/pharmacology , Animals , Antineoplastic Agents/pharmacokinetics , Biological Availability , Drug Design , Drug Discovery , Female , Humans , MCF-7 Cells , Mice , Mice, Nude , Rats , Rats, Sprague-Dawley , Rats, Wistar , Selective Estrogen Receptor Modulators/pharmacokinetics , Thiophenes/chemistry , Thiophenes/pharmacokinetics , Xenograft Model Antitumor AssaysABSTRACT
In this issue of Cancer Cell, Jeselsohn et al. dissect the function of several of the most clinically important estrogen receptor alpha mutants associated with endocrine therapy resistance in breast cancer and demonstrate that they manifest disease-relevant neomorphic activities that likely contribute to tumor pathogenesis.