Dimethyl fumarate (DMF) is a fumaric acid ester registered for the treatment of relapsing‐remitting multiple sclerosis (RRMS). It induces protein succination leading to inactivation of cysteine‐rich ...proteins. It was first shown to possess cytoprotective and antioxidant effects in noncancer models, which appeared related to the induction of the nuclear factor erythroid 2 (NF‐E2)–related factor 2 (NRF2) pathway. DMF also displays antitumor activity in several cellular and mice models. Recently, we showed that the anticancer mechanism of DMF is dose‐dependent and is paradoxically related to the decrease in the nuclear translocation of NRF2. Some other studies performed indicate also the potential role of DMF in cancers, which are dependent on the NRF2 antioxidant and cellular detoxification program, such as KRAS‐mutated lung adenocarcinoma. It, however, seems that DMF has multiple biological effects as it has been shown to also inhibit the transcription factor nuclear factor kappa‐light‐chain‐enhancer of activated B cells (NF‐κB), thus blocking downstream targets that may be involved in the development and progression of inflammatory cascades leading to various disease processes, including tumors, lymphomas, diabetic retinopathy, arthritis, and psoriasis. Herein, we present the current status and future directions of the use of DMF in various diseases models with particular emphases on its targeting of specific intracellular signal transduction cascades in cancer; to shed some light on its possible mode of action.
NRF2 is a major transcription factor regulating the expression of antioxidative/detoxifying enzymes, involved in oncogenic processes and drug resistance. We aimed to identify molecular alterations ...associated with NRF2 activation in endometrial carcinoma (EC).
Ninety patients treated (2012-2017) for localized/locally advanced EC were included in this study. Formalin-fixed paraffin-embedded tissue samples were processed for immunohistochemical (NRF2 and Mismatch Repair proteins) analyses. Next generation sequencing (NGS) of a panel of genes including POLE, TP53, NFE2L2, KEAP1 and CUL3 was performed using Ampliseq panels on Ion Torrent PGM (ThermoFisher). NRF2 activity was assessed by NQO1, GCLC, and AKR1C3 mRNA expressions, using TaqMan assays and quantitative RT-PCR.
Tumors were classified as POLE exonuclease domain mutated (N = 3, 3%), MMR-deficient (MSI-like) (N = 28, 31%), TP53 mutated (Copy-number high-like) (N = 22, 24%), and other tumors (Copy-number low-like) (N = 32, 36%). NRF2 nuclear immunostaining did not correlate with NRF2 target genes expression. The 3 tumors with highest NRF2 target genes expression harbored oncogenic KEAP1 or NFE2L2 mutations. Low NQO1 mRNA and protein levels were observed in the TP53 mutated subgroup compared to others tumors (p < .05) and in silico analyses of The Cancer Genome Atlas data further indicated that NQO1 mRNA levels were lower in serous compared to endometrioid copy-number high EC.
In contrast with previous reports based on immunohistochemistry, our study indicates that NRF2 activation is a rare event in EC, associated with NFE2L2 or KEAP1 mutations. The subset of aggressive EC with low NQO1 mRNA level might represent a specific subgroup, which could be sensitive to combination therapies targeting oxidative stress.
Acute paediatric leukaemia is diagnosed and monitored via bone marrow aspirate assessment of blasts as a measure of minimal residual disease. Liquid biopsies in the form of blood samples could ...greatly reduce the need for invasive bone marrow aspirations, but there are currently no blood markers that match the sensitivity of bone marrow diagnostics. Circulating extracellular vesicles (EVs) represent candidate biomarkers that may reflect the blast burden in bone marrow, and several studies have reported on the utility of EVs as biomarkers for adult haematological malignancies. Increased levels of EVs have been reported for several haematological malignancies, and we similarly report here elevated EV concentrations in plasma from paediatric BCP‐ALL patients. Plasma EVs are very heterogeneous in terms of their cellular origin, thus identifying a cancer selective EV‐marker is challenging. Here, we undertook a reductionistic approach to identify protein markers selectively associated to plasma EVs derived from BCP‐ALL patients. The EV proteome of primary BCP‐ALL cell‐derived EVs were compared against EVs from healthy donor B cells and the BCP‐ALL cell line REH, and further against EVs isolated from plasma of healthy paediatric donors and paediatric BCP‐ALL patients. With this approach, we identified a signature of 6 proteins (CD317, CD38, IGF2BP1, PCNA, CSDE1, and GPR116) that were specifically identified in BCP‐ALL derived EVs only and not in healthy control EVs, and that could be exploited as diagnostic biomarkers.
Comparative profiling of extracellular vesicles from plasma and from isolated B cells from pediatric BCP‐ALL patients and healthy donors to define circulating blast‐derived vesicles.
Coumarins and coumarin derivatives as well as diallyl polysulfides are well known as anticancer drugs. In order to find new drugs with anticancer activities, we combined coumarins with polysulfides ...in the form of di-coumarin polysulfides. These novel compounds were tested in the HCT116 colorectal cancer cell line. It turned out that they reduced cell viability of cancer cells in a time and concentration dependent manner. Cells tested with these coumarin polysulfides accumulate in the G2/M phase of the cell cycle and finally they go into apoptosis. A decrease in bcl-2 level, and increase in the level of bax, cytochrome c release into the cytosol, cleavage of caspase 3/7and PARP suggested that coumarin polysulfides induced the intrinsic pathway of apoptosis. Comparison of these new coumarin compounds with the well known diallyl polysulfides revealed that the coumarin disulfides were more active than the corresponding diallyl disulfides. The activities of the coumarin tetrasulfides and the corresponding diallyl tetrasulfides are similar. The novel coumarin compounds regulated the phosphatase activity of the cell cycle regulating cdc25 family members, indicating that these phosphatases are implicated in the induction of cell cycle arrest and possibly in apoptosis induction as well. In addition, coumarin polysulfides also down-regulated the level of cdc25C, which also contributed to the arrest in the G2-phase of the cell cycle.
The transcription factor NRF2 (NFE2L2), regulates important antioxidant and cytoprotective genes. It enhances cancer cell proliferation and promotes chemoresistance in several cancers. Dimethyl ...fumarate (DMF) is known to promote NRF2 activity in noncancer models. We combined
and
methods to examine the effect of DMF on cancer cell death and the activation of the NRF2 antioxidant pathway. We demonstrated that at lower concentrations (<25 μmol/L), DMF has a cytoprotective role through activation of the NRF2 antioxidant pathway. At higher concentrations, however (>25 μmol/L), DMF caused oxidative stress and subsequently cytotoxicity in several cancer cell lines. High DMF concentration decreases nuclear translocation of NRF2 and production of its downstream targets. The pro-oxidative and cytotoxic effects of high concentration of DMF were abrogated by overexpression of NRF2 in OVCAR3 cells, suggesting that DMF cytotoxicity is dependent of NRF2 depletion. High concentrations of DMF decreased the expression of DJ-1, a NRF2 protein stabilizer. Using DJ-1 siRNA and expression vector, we observed that the expression level of DJ-1 controls NRF2 activation, antioxidant defenses, and cell death in OVCAR3 cells. Finally, antitumoral effect of daily DMF (20 mg/kg) was also observed in
in two mice models of colon cancer. Taken together, these findings implicate the effect of DJ-1 on NRF2 in cancer development and identify DMF as a dose-dependent modulator of both NRF2 and DJ-1, which may be useful in exploiting the therapeutic potential of these endogenous antioxidants.
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Systemic sclerosis (SSc) is an autoimmune disease with fibrosis of the skin and internal organs and vascular alterations. Dysregulations in the oxidant/antioxidant balance are known to be a major ...factor in the pathogenesis of the disease. Indeed, reactive oxygen species (ROS) trigger neoepitopes leading to a breach of immune tolerance and autoimmune responses, activate fibroblasts to proliferate and to produce excess of type I collagen. ROS also alter endothelial cells leading to vascular dysfunction. Glutathione (GSH) is the most potent antioxidant system in eukaryotic cells. Numerous studies have reported a defect in GSH in SSc animal models and humans, but the origin of this defect remains unknown. The transcription factor NRF2 is a key player in the antioxidant defense, as it can induce the transcription of antioxidant and cytoprotective genes, including GSH, through its interaction with the antioxidant response elements. In this work, we investigated whether NRF2 could be implicated in the pathogenesis of SSc, and if this pathway could represent a new therapeutic target in this orphan disease with no curative medicine. Skin biopsies from 11 patients and 10 controls were harvested, and skin fibroblasts were extracted. Experimental SSc was induced both in BALB/c and in
mice by daily intradermal injections of hypochloric acid. In addition, diseased BALB/c mice were treated with an
agonist, dimethyl fumarate, or placebo. A drop in
and target genes mRNA levels was observed in skin fibroblasts of SSc patients compared to controls. Moreover, the
pathway is also downregulated in skins and lungs of SSc mice. In addition, we observed that
mice have a more severe form of SSc with increased fibrosis and inflammation compared to wild-type SSc mice. Diseased mice treated with the
agonist dimethyl fumarate (DMF) exhibited reduced fibrosis and immune activation compared to untreated mice. The
treatment of skin fibroblasts from SSc mice with DMF restores GSH intracellular content, decreases ROS production and cell proliferation. These results suggest that the
pathway is highly dysregulated in human and SSc mice with deleterious consequences on fibrosis and inflammation and that Nrf2 modulation represents a therapeutic target in SSc.
KRAS mutation, one of the most common molecular alterations observed in adult carcinomas, was reported to activate the anti-oxidant program driven by the transcription factor NRF2 (Nuclear ...factor-erythroid 2-related factor 2). We previously observed that the antitumoral effect of Dimethyl fumarate (DMF) is dependent of NRF2 pathway inhibition. We used
methods to examine the effect of DMF on cell death and the activation of the NRF2/DJ-1 antioxidant pathway. We report here that DMF is preferentially cytotoxic against KRAS mutated cancer cells. This effect was observed in patient-derived cancer cell lines harbouring a G12V KRAS mutation, compared with cell lines without such a mutation. In addition, KRAS*G12V over-expression in the human Caco-2 colon cancer cell line significantly promoted DMF-induced cell death, as well as DMF-induced- reactive oxygen species (ROS) formation and -glutathione (GSH) depletion. Moreover, in contrast to malignant cells, our data confirms that the same concentration of DMF has no significant cytotoxic effects on non-tumorigenic human ARPE-19 retinal epithelial, murine 3T3 fibroblasts and primary mice bone marrow cells; but is rather associated with NRF2 activation, decreased ROS and increased GSH levels. Furthermore, DJ-1 down-regulation experiments showed that this protein does not play a protective role against NRF2 in non-tumorigenic cells, as it does in malignant ones. This, interestingly, could be at the root of the differential effect of DMF observed between malignant and non-tumorigenic cells. Our results suggest for the first time that the dependence on NRF2 observed in mutated KRAS malignant cells makes them more sensitive to the cytotoxic effect of DMF, which thus opens up new prospects for the therapeutic applications of DMF.
Human papillomavirus (HPV) E6 and E7 oncoproteins are critical for development and maintenance of the malignant phenotype in HPV-induced cancers. These two viral oncoproteins interfere with a ...plethora of cellular pathways, including the regulation of cell cycle and the control of apoptosis, which are critical in maintaining normal cellular functions. E6 and E7 bind directly with certain components of the Ubiquitin Proteasome System (UPS), enabling them to manipulate a number of important cellular pathways. These activities are the means by which HPV establishes an environment supporting the normal viral life cycle, however in some instances they can also lead to the development of malignancy. In this review, we have discussed how E6 and E7 oncoproteins from alpha and beta HPV types interact with the components of the UPS, and how this interplay contributes to the development of cancer.
Molecular classification of endometrial carcinoma has been proposed to predict survival. However, its role in patient management remains to be determined. We aimed to identify whether a molecular and ...immunohistochemical classification of endometrial carcinoma could improve decision-making for adjuvant therapy.
All consecutive patients treated for endometrial carcinoma between 2010 and 2017 at Cochin University Hospital were included. Clinical risk of relapse was based on European Society for Medical Oncology-European Society of Gynaecological Oncology-European SocieTy for Radiotherapy & Oncology (ESMO-ESGO-ESTRO) consensus. The clinical event of interest was event-free survival. Formalin-fixed paraffin-embedded tissue samples were processed for histopathological analysis and DNA extraction. The nuclear expression of mismatch repair and TP53 proteins was analyzed by immunohistochemistry. Next-generation sequencing of a panel of 15 genes including
and
was performed using Ampliseq panels on Ion Torrent PGM (ThermoFisher). Tumors were allocated into four molecular groups using a sequential method based on next-generation sequencing and immunohistochemistry data: (1)
/ultramutated-like; (2) MSI/hypermutated-like (mismatch repair-deficient); (3)
-mutated (without
mutations or mismatch repair deficiency); (4) not otherwise specified (the remaining tumors).
159 patients were included; 125 tumors were available for molecular characterization and distributed as follows: (1)
/ultramutated-like: n=4 (3%); (2) MSI/hypermutated-like: n=35 (30%); (3)
-mutated: n=30 (25%); and (4) not otherwise specified: n=49 (42%). Assessing the TP53 status by immunohistochemistry only rather than next-generation sequencing would have misclassified 6 tumors (5%).
-mutated tumors were associated with poor prognosis, independently of International Federation of Gynecology and Obstetrics (FIGO) stage and histological grade (Cox-based adjusted hazard ratio (aHR) 5.54, 95% CI 2.30 to 13.4), and independently of clinical risk of relapse (aHR 3.92, 95% CI 1.59 to 9.64). Among patients with FIGO stage I-II tumors, 6 (38%)
-mutated tumors had low/intermediate clinical risk of relapse and did not receive adjuvant chemotherapy or radiotherapy.
Endometrial carcinoma molecular classification identified potentially under-treated patients with poor molecular prognosis despite being at low/intermediate clinical risk of relapse. Consideration of molecular classification in adjuvant therapeutic decisions should be evaluated in prospective trials.
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