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Fuino L, Bali P, Wittmann S, Donapaty S, Guo F, Yamaguchi H, Wang HG, Atadja P, Bhalla KHistone deacetylase inhibitor LAQ824 down-regulates Her-2 and sensitizes human breast cancer cells to trastuzumab, taxotere, gemcitabine, and epothilone B. Mol Cancer Ther 2: 971-984
Abstract and Figures
Histone deacetylase inhibitors induce hyperacetylation of the amino-terminal lysine residues of the core nucleosomal histones, which results in chromatin remodeling and altered gene expression. Present studies demonstrate that exposure to a novel hydroxamic acid analogue histone deacetylase inhibitor, LAQ824, induced p21WAF1 and p27KIP1 and caused growth arrest and apoptosis of human breast cancer SKBR-3 and BT-474 cells that possess amplification and overexpression of Her-2/neu. Treatment with LAQ824 depleted the mRNA and protein levels of Her-2/neu-encoded Her-2, which was associated with attenuation of pAKT, c-Raf-1, and phosphorylated mitogen-activated protein kinase levels. LAQ824 also induced the acetylation of heat shock protein (hsp) 90, resulting in inhibition of its binding to ATP, which has been shown to impair the chaperone association of hsp 90 with its client proteins, Her-2, AKT, and c-Raf-1. Consistent with this, treatment with LAQ824 shifted the binding of Her-2 from hsp 90 to hsp 70, promoting proteasomal degradation of Her-2. Thus, LAQ824 depletes Her-2 through two mechanisms: attenuation of its mRNA levels and promotion of its degradation by the proteasome. Following LAQ824 treatment, the cell membrane association, autotyrosine phosphorylation, and colocalization of Her-2 with HER-3 also declined. Cotreatment with LAQ824 significantly increased trastuzumab-induced apoptosis of BT-474 and SKBR-3 cells. This was associated with greater attenuation of Her-2, c-Raf-1, and pAKT levels. LAQ824 also enhanced taxotere-induced, epothilone B-induced, and gemcitabine-induced apoptosis of BT-474 and SKBR-3 cells. These findings suggest that LAQ824 is active against human breast cancer cells and has the potential to improve the efficacy of trastuzumab, taxotere, gemcitabine, and epothilone B against breast cancer with Her-2/neuamplification.
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... Urinary tract cancers account for approximately 21,000 new diagnoses and 5,000 deaths annually in the UK [1]. Approximately 90% are composed of transitional cell carcinoma (TCC) histology and are treated with platinum based chemotherapy and PD-1/PD-L1 directed immunotherapy. ...
... AURORA trial eligibility criteria Inclusion criteria1 Histologically confirmed cancer of the urinary tract with squamous cell carcinoma histology and without any TCC component. Mixed non-TCC histology is allowed if squamous cell carcinoma is the predominant histology 2 Newly diagnosed or progressive measurable disease as defined by RECIST version 1.1. ...
... Author details 1 ...
Background
Bladder and urinary tract cancers account for approximately 21,000 new diagnoses and 5,000 deaths annually in the UK. Approximately 90% are transitional cell carcinomas where advanced disease is treated with platinum based chemotherapy and PD-1/PD-L1 directed immunotherapy. Urinary tract squamous cell carcinoma (UTSCC) accounts for about 5% of urinary tract cancers overall making this a rare disease. We have yet to establish definitive systemic treatment options for advanced UTSCC.
Preliminary translational data, from UTSCC patient tumour samples, indicate high PD-L1 expression and tumour infiltrating lymphocytes in a proportion of cases. Both of these features are associated with differential gene expression consistent with a tumour/immune microenvironment predicted to be susceptible to immune checkpoint directed immunotherapy which we will evaluate in the AURORA trial.
Methods
AURORA is a single arm, open-label, multicentre,UK phase II clinical trial. 33 patients will be recruited from UK secondary care sites. Patients with UTSCC, suitable for treatment with palliative intent, will receive atezolizumab PD-L1 directed immunotherapy (IV infusion, 1680 mg, every 28 days) for one year if tolerated. Response assessment, by cross sectional imaging will occur every 12 weeks. AURORA uses a Simon’s 2-stage optimal design with best overall objective response rate (ORR, by RECIST v1.1) at a minimum of 12 weeks from commencing treatment as the primary endpoint. Secondary endpoints will include overall survival, progression-free survival, duration of response, magnitude of response using waterfall plots of target lesion measurements, quality of life using the EORTC QLQ-C30 tool, safety and tolerability (CTCAE v5) and evaluation of potential biomarkers of treatment response including PD-L1 expression. Archival tumour samples and blood samples will be collected for translational analyses.
Discussion
If this trial shows atezolizumab to be safe and effective it may lead to a future late phase randomised controlled trial in UTSCC. Ultimately, we hope to provide a new option for treatment for such patients.
Trial registrations
EudraCT Number: 2021-001995-32 (issued 8th September 2021); ISRCTN83474167 (registered 11 May 2022); NCT05038657 (issued 9th September 2021).
... For Genistein 10µM, which we had previously prioritised among the plant polyphenols, we found dose-dependent differences in the set of drugs prioritized as potential combination candidates in the list of prioritized drugs. Importantly, among the predicted target network synergistic drugs, we found 8 drugs common to all doses, drugs such as fulvestrant [52], pralatrexate [53], dacinostat [54], camptothecin [55], indibulin [56], gemcitabine [57], daunorubicin [58], and epirubicin [59]. The majority of the drugs in this category, across all dosages, have been previously investigated and recommended for use as antineoplastics in breast and other cancers. ...
Background
Prioritizing candidate drugs based on genome-wide expression data is an emerging approach in systems pharmacology due to its holistic perspective for preclinical drug evaluation. In the current study, a network-based approach was proposed and applied to prioritize plant polyphenols and identify potential drug combinations in breast cancer. We focused on MEK5/ERK5 signalling pathway genes, a recently identified potential drug target in cancer with roles spanning major carcinogenesis processes.
Results
By constructing and identifying perturbed protein–protein interaction networks for luminal A breast cancer, plant polyphenols and drugs from transcriptome data, we first demonstrated their systemic effects on the MEK5/ERK5 signalling pathway. Subsequently, we applied a pathway-specific network pharmacology pipeline to prioritize plant polyphenols and potential drug combinations for use in breast cancer. Our analysis prioritized genistein among plant polyphenols. Drug combination simulations predicted several FDA-approved drugs in breast cancer with well-established pharmacology as candidates for target network synergistic combination with genistein. This study also highlights the concept of target network enhancer drugs, with drugs previously not well characterised in breast cancer being prioritized for use in the MEK5/ERK5 pathway in breast cancer.
Conclusion
This study proposes a computational framework for drug prioritization and combination with the MEK5/ERK5 signaling pathway in breast cancer. The method is flexible and provides the scientific community with a robust method that can be applied to other complex diseases.
... LAQ824 reduced the expression of ERa, PRb, c-Myc, cyclin D1 and HDAC6 in breast cancer cells, leading to suppression of cellular proliferation (107). LAQ-824 sensitized drug sensitivity, including taxotere, epothilone B, trastuzumab and gemcitabine, via downregulation of HER-2 expression in breast cancer cells (108). LAQ824 was found to work as a sensitizer to immunotherapy with adoptive T-cell transfer in melanoma (109). ...
Breast cancer is one of the common malignancies with poor prognosis worldwide. The treatment of breast cancer patients includes surgery, radiation, hormone therapy, chemotherapy, targeted drug therapy and immunotherapy. In recent years, immunotherapy has potentiated the survival of certain breast cancer patients; however, primary resistance or acquired resistance attenuate the therapeutic outcomes. Histone acetyltransferases induce histone acetylation on lysine residues, which can be reversed by histone deacetylases (HDACs). Dysregulation of HDACs via mutation and abnormal expression contributes to tumorigenesis and tumor progression. Numerous HDAC inhibitors have been developed and exhibited the potent anti-tumor activity in a variety of cancers, including breast cancer. HDAC inhibitors ameliorated immunotherapeutic efficacy in cancer patients. In this review, we discuss the anti-tumor activity of HDAC inhibitors in breast cancer, including dacinostat, belinostat, abexinostat, mocetinotat, panobinostat, romidepsin, entinostat, vorinostat, pracinostat, tubastatin A, trichostatin A, and tucidinostat. Moreover, we uncover the mechanisms of HDAC inhibitors in improving immunotherapy in breast cancer. Furthermore, we highlight that HDAC inhibitors might be potent agents to potentiate immunotherapy in breast cancer.
... Many papers throughout the subsequent decades from the academic or industry sector seemed to show that trastuzumab treatment either eliminates HER2 expression or inhibits its phosphorylation and downstream signaling, promoting the mechanistically conflicting narrative that it is a HER2 inhibitor of one kind or another (26)(27)(28)(29)(30). We and others see little evidence of such activity with trastuzumab and this is now widely acknowledged within the scientific community and evident in the immunoblots on various papers, although direct discussion of this taboo topic is generally avoided (31)(32)(33)(34)(35)(36)(37)(38)(39). I also refer readers to a more in-depth and recent review of the specific topic of reproducibility issues in trastuzumab related preclinical research (40). ...
Activation of p53 regulates a transcriptional program that can cause cell cycle arrest, senescence, apoptosis, and ferroptosis, which are potent tumor suppressive mechanisms. Unexpectedly, Makino and colleagues show in this issue of Cancer Research that the constitutive activation of p53 in murine hepatocytes leads to tumor development. Detailed analyses indicate that p53 activation leads to loss of hepatocytes, increased expression of chemokines and humoral factors, and expansion of the hepatic progenitor cell population. These progenitor cells are highly proliferative, show chromosomal instability, and eventually transform. In chronic liver disease in humans, activation of p53 is associated with increased liver cancer development. This study highlights the complexity and non-cell autonomous nature of the physiologic p53 response.
See related article by Makino et al., p. 2860
... Many papers throughout the subsequent decades from the academic or industry sector seemed to show that trastuzumab treatment either eliminates HER2 expression or inhibits its phosphorylation and downstream signaling, promoting the mechanistically conflicting narrative that it is a HER2 inhibitor of one kind or another (26)(27)(28)(29)(30). We and others see little evidence of such activity with trastuzumab and this is now widely acknowledged within the scientific community and evident in the immunoblots on various papers, although direct discussion of this taboo topic is generally avoided (31)(32)(33)(34)(35)(36)(37)(38)(39). I also refer readers to a more in-depth and recent review of the specific topic of reproducibility issues in trastuzumab related preclinical research (40). ...
The pharmaceutical inactivation of driver oncogenes has revolutionized the treatment of cancer replacing cytotoxic chemotherapeutic approaches with kinase inhibitor therapies for many types of cancers. This approach has not yet been realized for the treatment of HER2-amplified cancers. The monotherapy activities associated with HER2-targeting antibodies and kinase inhibitors are modest, and their clinical use has been in combination with, and not in replacement of cytotoxic chemotherapies. This stands in sharp contrast to achievements in the treatment of many other oncogene-driven cancers. The mechanism-based treatment hypothesis regarding the inactivation of HER2 justifies expectations far beyond what is currently realized. Overcoming this barrier requires mechanistic insights that can fuel new directions for pursuit, but scientific investigation of this treatment hypothesis, particularly with regards to trastuzumab, has been complicated by conflicting and confusing data sets, ironclad dogma, and mechanistic conclusions that have repeatedly failed to translate clinically. We are now approaching a point of convergence regarding the challenges and resiliency in this tumor driver, and I will provide here a review and opinion to inform where we currently stand with this treatment hypothesis and where the future potential lies.
... Additionally, entinostat has been shown to increase the expression of ERα in ER-negative models and stimulate sensitivity of these tumours to aromatase inhibitors [66]. Finally, dacinostat in combination with trastuzumab and chemotherapy has shown antitumour activity and a corresponding decline in HER2 and pAKT levels in HER2-amplified breast cancer cell lines [67]. ...
Simple Summary
Epigenetic therapies are promising agents for overcoming clinical resistance to conventional treatments in breast cancer. In the assessed trials, the use of epigenetic therapies for the management of breast cancer has not translated from the pre-clinical to clinical setting. However, novel epigenetic treatments remain promising, especially in the era of personalized medicine and improved genomic evaluation. The aim of our review was to assess the published evidence for the clinical utility of epigenetic therapies and their biomarkers in breast cancer and the potential value of epigenetic biomarkers to direct clinical management.
Abstract
Epigenetic therapies remain a promising, but still not widely used, approach in the management of patients with cancer. To date, the efficacy and use of epigenetic therapies has been demonstrated primarily in the management of haematological malignancies, with limited supportive data in solid malignancies. The most studied epigenetic therapies in breast cancer are those that target DNA methylation and histone modification; however, none have been approved for routine clinical use. The majority of pre-clinical and clinical studies have focused on triple negative breast cancer (TNBC) and hormone-receptor positive breast cancer. Even though the use of epigenetic therapies alone in the treatment of breast cancer has not shown significant clinical benefit, these therapies show most promise in use in combinations with other treatments. With improving technologies available to study the epigenetic landscape in cancer, novel epigenetic alterations are increasingly being identified as potential biomarkers of response to conventional and epigenetic therapies. In this review, we describe epigenetic targets and potential epigenetic biomarkers in breast cancer, with a focus on clinical trials of epigenetic therapies. We describe alterations to the epigenetic landscape in breast cancer and in treatment resistance, highlighting mechanisms and potential targets for epigenetic therapies. We provide an updated review on epigenetic therapies in the pre-clinical and clinical setting in breast cancer, with a focus on potential real-world applications. Finally, we report on the potential value of epigenetic biomarkers in diagnosis, prognosis and prediction of response to therapy, to guide and inform the clinical management of breast cancer patients.
The latest studies identified the histone deacetylase (HDAC) class of enzymes as strategic components of the complex molecular machinery underlying inflammation in cystic fibrosis (CF). Compelling new support has been provided for HDAC6 isoform as a key player in the generation of the dysregulated proinflammatory phenotype in CF, as well as in the immune response to the persistent bacterial infection accompanying CF patients. We herein provide in vivo proof-of-concept (PoC) of the efficacy of selective HDAC6 inhibition in contrasting the pro-inflammatory phenotype in a mouse model of chronic P. aeruginosa respiratory infection. Upon careful selection and in-house re-profiling (in vitro and cell-based assessment of acetylated tubulin level through Western blot analysis) of three potent and selective HDAC6 inhibitors as putative candidates for the PoC, we engaged the best performing compound 2 for pre-clinical studies. Compound 2 demonstrated no toxicity and robust anti-inflammatory profile in a mouse model of chronic P. aeruginosa respiratory infection upon repeated aerosol administration. A significant reduction of leukocyte recruitment in the airways, in particular neutrophils, was observed in compound 2-treated mice in comparison with the vehicle; moreover, quantitative immunoassays confirmed a significant reduction of chemokines and cytokines in lung homogenate. This effect was also associated with a modest reduced bacterial load after compound 2-treatment in mice compared to the vehicle. Our study is of particular significance since it demonstrates for the first time the utility of selective drug-like HDAC6 inhibitors in a relevant in vivo model of chronic P. aeruginosa infection, thus supporting their potential application for reverting CF phenotype.
p>Firstly investigation addressed the ability of the anti-apoptotic protein BAG-1, which potentiates the oestrogen receptor in breast cancer, to also modulate PPARγ (peroxisome proliferator activated receptor γ), a nuclear hormone receptor important for lipid and glucose homeostasis. PPARγ agonists represent a potential therapeutic approach for breast cancer, inducing cell cycle arrest, apoptosis and differentiation. Prostaglandin J2 (PGJ2) stimulated PPARγ mediated expression of HSP70, a BAG-1 binding partner, but not BAG-1 isoform expression. BAG-1 over expression did not alter PGJ2 dependent transcription, or interfere with PGJ2-induced cell cycle arrest or differentiation. However, BAG-1 did not interfere with induction of cell death by PGJ2. Thus, BAG-1 is unlikely to directly modulate PPAR, but its known over expression in some breast cancers might limit potential clinical efficacy of PPARγ agonists, by suppression of PPARγ-induced cell death pathways.
Secondly, a depsipeptide natural compound, Spiruchostatin A, was characterised with respect to its histone deacetylase (HDAC) activity and ability to induce cell cycle arrest, differentiation and cell death in breast cancer cells. Differences in potency, cell cycle arrest characteristics and induction of cell death were detected for Spiruchostatin A in breast cancer versus normal cells. Comparative investigation of the depsipeptide HDAC inhibitors Spiruchostatin A and FK-228 demonstrated class I HDAC selectivity in distinction to hydroxamate pan HDAC class I and II inhibitors. Class I HDAC selectivity allowed for the retention of anti breast cancer cell histone acetylation pharmacodynamics with implications for in-vivo surrogate markers of downstream biological effects of these compounds.</p
Carcinoma of the breast and ovary account for one-third of all cancers occurring in women and together are responsible for
approximately one-quarter of cancer-related deaths in females. The HER-2/neu proto-oncogene is amplified in 25 to 30 percent
of human primary breast cancers and this alteration is associated with disease behavior. In this report, several similarities
were found in the biology of HER-2/neu in breast and ovarian cancer, including a similar incidence of amplification, a direct
correlation between amplification and over-expression, evidence of tumors in which overexpression occurs without amplification,
and the association between gene alteration and clinical outcome. A comprehensive study of the gene and its products (RNA
and protein) was simultaneously performed on a large number of both tumor types. This analysis identified several potential
shortcomings of the various methods used to evaluate HER-2/neu in these diseases (Southern, Northern, and Western blots, and
immunohistochemistry) and provided information regarding considerations that should be addressed when studying a gene or gene
product in human tissue. The data presented further support the concept that the HER-2/neu gene may be involved in the pathogenesis
of some human cancers.
The serine/threonine kinase Raf-1 functions downstream of Rats in a signal transduction cascade which transmits mitogenic stimuli from the plasma membrane to the nucleus. Raf-1 integrates signals coming from extracellular factors and, in turn, activates its substrate, MEK kinase. MEK activates mitogen-activated protein kinase (MAPK), which phosphorylates other kinases as well as transcription factors. Raf-1 exists in a complex with HSP90 and other proteins. The benzoquinone ansamycin geldanamycin (GA) binds to HSP90 and disrupts the Raf-1-HSP90 multimolecular complex, leading to destabilization of Raf-1. In this study, we examined whether Raf-1 destabilization is sufficient to block the Raf-1-MEK-MAPK signalling pathway and whether GA specifically inactivates the Raf-1 component of this pathway. Using the model system of NIH 3T3 cells stimulated with phorbol 12-myristate 13-acetate (PMA), we show that GA does not affect the ability of protein kinase C alpha to be activated by phorbol esters, but it does block activation of MEK and MAPK. Further, GA does not decrease the activity of constitutively active MEK in transiently transfected cells. Finally, disruption of the Raf-1-MEK-MAPK signalling pathway by GA prevents both the PMA-induced proliferative response and PMA-induced activation of a MAPK-sensitive nuclear transcription factor. Thus, we demonstrate that interaction between HSP90 and Raf-1 is a sine qua non for Raf stability and function as a signal transducer and that the effects observed cannot be attributed to a general impairment of protein kinase function.
Estrogen receptors (ERs) mediate most of the biological effects of estrogen in mammary and uterine epithelial cells by binding
to estrogen response elements in the promoter region of target genes or through protein-protein interactions. Anti-estrogens
such as tamoxifen inhibit the growth of ER-positive breast cancers by reducing the expression of estrogen-regulated genes.
However, anti-estrogen-resistant growth of ER-positive tumors remains a significant clinical problem. Here we show that phosphatidylinositol
(PI) 3-kinase and AKT activate ERα in the absence of estrogen. Although PI 3-kinase increased the activity of both estrogen-independent
activation function 1 (AF-1) and estrogen-dependent activation function 2 (AF-2) of ERα, AKT increased the activity of only
AF-1. PTEN and a catalytically inactive AKT decreased PI 3-kinase-induced AF-1 activity, suggesting that PI 3-kinase utilizes
AKT-dependent and AKT-independent pathways in activating ERα. The consensus AKT phosphorylation site Ser-167 of ERα is required
for phosphorylation and activation by AKT. In addition, LY294002, a specific inhibitor of the PI 3-kinase/AKT pathway, reduced
phosphorylation of ERα in vivo. Moreover, AKT overexpression led to up-regulation of estrogen-regulated pS2 gene, Bcl-2, and macrophage inhibitory cytokine
1. We demonstrate that AKT protects breast cancer cells from tamoxifen-induced apoptosis. Taken together, these results define
a molecular link between activation of the PI 3-kinase/AKT survival pathways, hormone-independent activation of ERα, and inhibition
of tamoxifen-induced apoptotic regression.
The tumor suppressor p53 exerts antiproliferation effects through its ability to function as a sequence-specific DNA-binding transcription factor. Here, we demonstrate that p53 can be modified by acetylation both in vivo and in vitro. Remarkably, the site of p53 that is acetylated by its coactivator, p300, resides in a C-terminal domain known to be critical for the regulation of p53 DNA binding. Furthermore, the acetylation of p53 can dramatically stimulate its sequence-specific DNA-binding activity, possibly as a result of an acetylation-induced conformational change. These observations clearly indicate a novel pathway for p53 activation and, importantly, provide an example of an acetylation-mediated change in the function of a nonhistone regulatory protein. These results have significant implications regarding the molecular mechanisms of various acetyltransferase-containing transcriptional coactivators whose primary targets have been presumed to be histones.
'The amino termini of histones extend from the nucleosomal core and are modified by acetyltransferases and deacetylases during the cell cycle. These acetylation patterns may direct histone assembly and help regulate the unfolding and activity of genes.