Dehydroxymethylepoxyquinomicin Research Articles

Antitumor Activity of Dehydroxymethylepoxyquinomicin (DHMEQ) in Monotherapy and Combination with Cisplatin in the SKOV-3 Ovarian Cancer Model

The objective of this study was to evaluate the antitumor activity of DHMEQ as monotherapy and in combination with cisplatin in a human ovarian cancer xenograft model. Cisplatin was used as a comparator. To create the xenograft model, human ovarian cancer cells (SKOV-3 line) were subcutaneously implanted into immunodeficient mice. The study was conducted on female SCID Beige C.B-17 Cg-Prkdcscid Lystbg/Crl mice. Antitumor activity was determined by comparing tumor growth inhibition (TGI) in the treatment groups to that in the control group. Results showed that daily intraperitoneal administration of DHMEQ at a dose of 14 mg/kg following a single intraperitoneal dose of cisplatin at 4 mg/kg reduced tumor growth in the SKOV-3 cell line xenograft model.

A foretaste for pediatric glioblastoma therapy: targeting the NF-kB pathway with DHMEQ.

While pediatric glioblastomas are molecularly distinct from adult counterparts, the activation of NF-kB is partially shared by both subsets, playing key roles in tumor propagation and treatment response. We show that, in vitro, dehydroxymethylepoxyquinomicin (DHMEQ) impairs growth and invasiveness. Xenograft response to the drug alone varied according to the model, being more effective in KNS42-derived tumors. In combination, SF188-derived tumors were more sensitive to temozolomide while KNS42-derived tumors responded better to the combination with radiotherapy, with continued tumor regression. Taken together, our results strengthen the potential usefulness of NF-kB inhibition in future therapeutic strategies to overcome this incurable disease.

Influence of Dehydroxymethylepoxyquinomicin on Radiosensitivity of Thyroid Carcinoma TPC-1 Cells.

Objective To investigate the influence of dehydroxymethylepoxyquinomicin (DHMEQ), an NF-κB inhibitor, on radiosensitivity of thyroid carcinoma (TC) TPC-1 cells. Methods The isolation of CDl33 positive cells (CD133+ TPC-1) and negative cells (CD133− TPC-1) from TPC-1 cells used immunomagnetic bead sorting. After verification of the toxicity of DHMEQ to cells by MTT and cell cloning assays, the cells were divided into four groups, of which three groups were intervened by DHMEQ, 131I radiation, and DHMEQ +131I radiation, respectively, while the fourth group was used as a control without treatment. Alterations in cell growth, apoptosis, and cell cycle were observed. Results DHMEQ had certain toxic effects on TPC-1 cells, with an IC50 of 38.57 μg/mL (P < 0.05). DHMEQ inhibited CD133+ and CD133- TPC-1 proliferation and their clonogenesis after irradiation. DHMEQ + radiation contributed to a growth inhibition rate and an apoptosis rate higher than either or them alone (P < 0.05), with a more significant effect on CD133− TPC-1 than CD133+ TPC-1 under the same treatment conditions (P < 0.05). Conclusion DHEMQ can increase the radiosensitivity of TC cells to 131I, inhibit tumor cell growth, and promote apoptosis. However, its effect is less significant on CD133+ TPC-1 compared with CD133− TPC-1, which may be related to the stem cell-like properties of CD133+ cells. In the future, the application of DHMEQ in TC 131I radiotherapy will effectively improve the clinical effect of patients.

A New 1,2-Naphthoquinone Derivative with Anti-lung Cancer Activity.

1,2-Naphthoquinone (2-NQ) is a nucleophile acceptor that non-selectively makes covalent bonds with cysteine residues in various cellular proteins, and is also found in diesel exhaust, an air pollutant. This molecule has rarely been considered as a pharmacophore of bioactive compounds, in contrast to 1,4-naphthoquinone. We herein designed and synthesized a compound named N-(7,8-dioxo-7,8-dihydronaphthalen-1-yl)-2-methoxybenzamide (MBNQ), in which 2-NQ was hybridized with the nuclear factor-κB (NF-κB) inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) as a nucleophile acceptor. Although 50 µM MBNQ did not inhibit NF-κB signaling, 10 µM MBNQ induced cell death in the lung cancer cell line A549, which was insensitive to 2-NQ (10 µM). In contrast, MBNQ was less toxic in normal lung cells than 2-NQ. A mechanistic study showed that MBNQ mainly induced apoptosis, presumably via the activation of p38 mitogen-activated protein kinase (MAPK). Collectively, the present results demonstrate that the introduction of an appropriate substituent into 2-NQ constitutes a new biologically active entity, which will lead to the development of 2-NQ-based drugs.

Intravenous Administration of Dehydroxymethylepoxyquinomicin With Polymer Enhances the Inhibition of Pancreatic Carcinoma Growth in Mice.

Pancreatic cancer, which exhibits resistance to cytotoxic and molecular targeted drugs, has an extremely poor prognosis. Nuclear factor-κB (NF-κB) is constitutively activated in many pancreatic cancer cases. Although the NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ) has exhibited anti-cancer effects in pancreatic cancer models, its poor solubility limits its use to intraperitoneal administration. Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (PMB) forms stable polymer aggregates with DHMEQ. The stability of DHMEQ aggregated with PMB in the human blood was measured by high-performance liquid chromatography-mass spectrometry (HPLC-MS) ex vivo. Anti-pancreatic cancer effects in AsPC-1 and MIA PaCa-2 pancreatic cancer cells were evaluated by cell growth inhibition assay in vitro and tumor growth inhibition assay in vivo. DHMEQ aggregated with PMB (PMB-DHMEQ) remained detectable after 60 min of incubation in the human blood, whereas DHMEQ aggregated with carboxymethyl cellulose (CMC-DHMEQ) was barely detectable. PMB-DHMEQ significantly inhibited AsPC-1 and MIA PaCa-2 cell growth in vitro compared to CMC-DHMEQ. Intravenous administration of PMB-DHMEQ reduced the tumor volume and liver metastasis compared to untreated or CMC-DHMEQ-treated mice. Aggregation with PMB improved the solubility of DHMEQ, and effectively inhibited pancreatic cancer cell growth both in vitro and in vivo.

Inhibition of Cellular and Animal Inflammatory Disease Models by NF-κB Inhibitor DHMEQ.

General inflammatory diseases include skin inflammation, rheumatoid arthritis, inflammatory bowel diseases, sepsis, arteriosclerosis, and asthma. Although these diseases have been extensively studied, most of them are still difficult to treat. Meanwhile, NF-κB is a transcription factor promoting the expression of many inflammatory mediators. NF-κB is likely to be involved in the mechanism of most inflammatory diseases. We discovered a specific NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), about 20 years ago by molecular design from a natural product. It directly binds to and inactivates NF-κB components. It has been widely used to suppress cellular and animal inflammatory disease models and was shown to be potent in vivo anti-inflammatory activity without any toxicity. We have prepared ointment of DHMEQ for the treatment of severe skin inflammation. It inhibited inflammatory cytokine expressions and lowered the clinical score in mouse models of atopic dermatitis. Intraperitoneal (IP) administration of DHMEQ ameliorated various disease models of inflammation, such as rheumatoid arthritis, sepsis, and also graft rejection. It has been suggested that inflammatory cells in the peritoneal cavity would be important for most peripheral inflammation. In the present review, we describe the synthesis, mechanism of action, and cellular and in vivo anti-inflammatory activities and discuss the clinical use of DHMEQ for inflammatory diseases.

The designed NF-κB inhibitor, DHMEQ, inhibits KISS1R-mediated invasion and increases drug-sensitivity in mouse plasmacytoma SP2/0 cells.

Plasmacytoma is one of the most difficult types of leukemia to treat, and it often invades the bone down to the marrow resulting in the development of multiple myeloma. NF-κB is often constitutively activated, and promotes metastasis and drug resistance in neoplastic cells. The present study assessed the cellular anticancer activity of an NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on mouse plasmacytoma SP2/0 cells. Cellular invasion was measured by Matrigel chamber assay, and apoptosis was assessed by detecting caspase-3 cleavage and by flow cytometric analysis with Annexin V. DHMEQ inhibited constitutively activated NF-κB at nontoxic concentrations. DHMEQ was also shown to inhibit cellular invasion of SP2/0 cells, as well as human myeloma KMS-11 and RPMI-8226 cells. The metastasis PCR array indicated that DHMEQ induced a decrease in KISS1 receptor (KISS1R) expression in SP2/0 cells. Knockdown of KISS1R by small interfering RNA suppressed cellular invasion, suggesting that KISS1R may serve an essential role in the invasion of SP2/0 cells. Furthermore, DHMEQ enhanced cytotoxicity of the anticancer agent melphalan in SP2/0 cells. Notably, DHMEQ inhibited the expression of NF-κB-dependent anti-apoptotic proteins, such as Bcl-XL, FLIP, and Bfl-1. In conclusion, inhibition of constitutively activated NF-κB by DHMEQ may be useful for future anti-metastatic and anticancer strategies for the treatment of plasmacytoma.

Synergistic effect of 17-allylamino-17-demethoxygeldanamycin with dehydroxymethylepoxyquinomicin on the human anaplastic thyroid carcinoma cell line KTC2

The use of targeted inhibitors has shown promise as an effective approach in cancer therapy. However, targeted therapies based only on one drug, such as 17-allylamino-17-demethoxygeldanamycin (17-AAG), have limited success, partly because cancer cells engage alternate pathways for survival and proliferation. In the present study, we evaluated whether dehydroxymethylepoxyquinomicin (DHMEQ), a nuclear factor ?B (NF-?B) inhibitor, can enhance the antitumor activities of 17-AAG, a 90 kDa heat shock protein (Hsp90) inhibitor, in the anaplastic thyroid cancer cell line KTC2. We examined the effect of combined drug treatment vs single drug treatment on cell survival. Isobologram analysis was performed to distinguish the additive vs synergistic effects of the drug combination. Western blotting was performed to investigate apoptosis markers: caspase 3, poly(ADP-ribose) polymerase-one (PARP-1), B-cell lymphoma-extra large (Bcl-XL), X-linked inhibitor of apoptosis (XIAP) and cellular inhibitor of apoptosis 2 (cIAP-2). Compared to monotherapy, the combined treatment enhanced growth-inhibitory effects in a synergistic manner and strongly potentiated apoptosis. These results demonstrate the first in vitro evidence that a combination of Hsp90 and NF-?B inhibitors is a more effective modality for inhibiting cell proliferation and survival in anaplastic thyroid carcinoma cells than either agent alone, warranting further investigations.

Anticancer Activity of Novel NF-kappa B Inhibitor DHMEQ by Intraperitoneal Administration.

There have been great advances in the therapy of cancer and leukemia. However, there are still many neoplastic diseases that are difficult to treat. For example, it is often difficult to find effective therapies for aggressive cancer and leukemia. An NF-κB inhibitor named dehydroxymethylepoxyquinomicin (DHMEQ) was discovered in 2000. This compound was designed based on the structure of epoxyquinomicin isolated from a microorganism. It was shown to be a specific inhibitor that directly binds to and inactivates NF-κB components. Until now, DHMEQ has been used by many scientists in the world to suppress animal models of cancer and inflammation. Especially, it was shown to suppress difficult cancer models, such as hormone-insensitive breast cancer and prostate cancer, cholangiocarcinoma, and multiple myeloma. No toxicity has been reported so far. DHMEQ was administered via the intraperitoneal (IP) route in most of the animal experiments because of its simplicity. In the course of developmental studies, it was found that IP administration never increased the blood concentration of DHMEQ because of the instability of DHMEQ in the blood. It is suggested that inflammatory cells in the peritoneal cavity would be important for cancer progression, and that IP administration, itself, is important for the effectiveness and safety of DHMEQ. In the present review, we describe mechanism of action, its in vivo anticancer activity, and future clinical use of DHMEQ IP therapy.

Dehydroxymethylepoxyquinomicin, a novel nuclear factor-\u03baB inhibitor, prevents the development of cyclosporine A nephrotoxicity in a rat model

BackgroundCyclosporine A (CsA) is an essential immunosuppressant in organ transplantation. However, its chronic nephrotoxicity is an obstacle to long allograft survival that has not been overcome. Nuclear factor-κB (NF-κB) is activated in the renal tissue in CsA nephropathy. In this study, we aimed to investigate the effect of the specific NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), in a rat model of CsA nephrotoxicity.MethodsWe administered CsA (15 mg/kg) daily for 28 days to Sprague-Dawley rats that underwent 5/6 nephrectomy under a low-salt diet. We administered DHMEQ (8 mg/kg) simultaneously with CsA to the treatment group, daily for 28 days and evaluated its effect on CsA nephrotoxicity.ResultsDHMEQ significantly inhibited NF-κB activation and nuclear translocation due to CsA treatment. Elevated serum urea nitrogen and creatinine levels due to repeated CsA administration were significantly decreased by DHMEQ treatment (serum urea nitrogen in CsA + DHMEQ vs CsA vs control, 69 ± 6.4 vs 113.5 ± 8.8 vs 43.1 ± 1.1 mg/dL, respectively, p < 0.0001; serum creatinine in CsA + DHMEQ vs CsA vs control, 0.75 ± 0.02 vs 0.91 ± 0.02 vs 0.49 ± 0.02 mg/dL, respectively, p < 0.0001), and creatinine clearance was restored in the treatment group (CsA + DHMEQ vs CsA vs control, 2.57 ± 0.09 vs 1.94 ± 0.12 vs 4.61 ± 0.18 ml/min/kg, respectively, p < 0.0001). However, DHMEQ treatment did not alter the inhibitory effect of CsA on urinary protein secretion. The development of renal fibrosis due to chronic CsA nephrotoxicity was significantly inhibited by DHMEQ treatment (CsA + DHMEQ vs CsA vs control, 13.4 ± 7.1 vs 35.6 ± 18.4 vs 9.4 ± 5.4%, respectively, p < 0.0001), and these results reflected the results of renal functional assessment. DHMEQ treatment also had an inhibitory effect on the increased expression of chemokines, monocyte chemoattractant protein-1, and chemokine (c-c motif) ligand 5 due to repeated CsA administration, which inhibited the infiltration of macrophages and neutrophils into the renal tissue.ConclusionsThese findings suggest that DHMEQ treatment in combination therapy with CsA-based immunosuppression is beneficial to prevent the development of CsA-induced nephrotoxicity.

Anti‑inflammatory effects of the NF‑κB inhibitor dehydroxymethylepoxyquinomicin on ARPE‑19 cells.

The retinal pigment epithelium (RPE) is a polarized, monolayer of pigmented cells that forms the outer retinal layer. A key function of the RPE is to maintain the integrity of the photoreceptors mainly via phagocytosis and recycling of the digested photoreceptor outer segments. Moreover, RPE cells are a major source of inflammatory cytokines and chemokines, which play important roles in the activation of other immune cells under inflammatory conditions in the posterior segment of the eye. Dehydroxymethylepoxyquinomicin (DHMEQ) is a NF‑κB inhibitor and its structure is related to that of epoxyquinomicin C, which is an antibiotic. The present study evaluated the anti‑inflammatory effects of DHMEQ on a human retinal pigment epithelial cell line (ARPE‑19). It was revealed that high concentrations of DHMEQ (100µg/ml) induced apoptosis and necrosis of tumor necrosis factor (TNF)‑α‑stimulated ARPE‑19 cells. Furthermore, the percentage of intercellular adhesion molecule 1 (ICAM‑1)‑positive TNF‑α‑stimulated cells was significantly reduced in the presence of DHMEQ (10µg/ml), as determined by flow cytometry. It was also demonstrated that DHMEQ exposure significantly decreased the levels of interleukin (IL)‑8 and monocyte chemoattractant protein‑1 (MCP‑1) in the supernatant of cultured ARPE‑19 cells as determined by ELISA. Moreover, the protein expression levels of IL‑8 and MCP‑1 were significantly reduced in ARPE‑19 cells exposed to DHMEQ compared with cells exposed to dexamethasone. PCR array analysis revealed that DHMEQ reduced the expression levels of MCP‑1, ICAM‑1, IL‑6, Toll‑like receptor (TLR)2, TLR3 and TLR4. Therefore, the present results indicated that DHMEQ has anti‑inflammatory effects on TNF‑α‑stimulated ARPE‑19 cells. Thus, DHMEQ may have therapeutic potential for TNF‑α‑mediated inflammatory disorders of the eye.

MP59-01 NOVEL NUCLEAR FACTOR-κB ACTIVATION INHIBITOR, DEHYDROXYMETHYLEPOXYQUINOMICIN, PREVENTS THE DEVELOPMENT OF CHRONIC CYCLOSPORINE NEPHROPATHY

INTRODUCTION AND OBJECTIVE: The nephrotoxicity of the calcineurin inhibitors including cyclosporine is a major problem in the kidney transplantation. We investigated the effect of a novel nuclear factor-κB (NF-κB) activation inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on chronic cyclosporine nephropathy using a rat model. METHODS: We performed 5/6 nephrectomy in Sprague-Dawley rats bred with low sodium diet. These rats were treated with the intraperitoneal administration of relatively high doses of cyclosporine (15mg/kg daily) (cyclosporine group, N=6) or treated with 5% glucose solution (control group, N=6). The other group was additionally treated with the intraperitoneal administration of DHMEQ (8mg/kg daily) (DHMEQ treatment group, N=6). Urine samples were collected on day 28 for 24 hours. The blood was collected and the kidneys were harvested on day 29. The sections of the kidney samples with Masson-trichrome staining were scanned and the area of interstitial fibrosis was measured by using a software (Image J). The proteins in the cytoplasm and the nucleus were separately collected from the samples to measure the relative increase in NF-κB p65 translocation into the nucleus using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The creatinine clearance levels in the DHMEQ treatment group were significantly higher in comparison with the cyclosporine group (0.74 ± 0.11 ml/min vs. 0.55 ± 0.05 ml/min, respectively). The Area measurements demonstrated that the interstitial fibrosis in the renal cortex less developed in the DHMEQ treatment group than those in the cyclosporine group (13.4 ± 7.0 % vs. 35.5 ± 18.3 %, respectively). The ELISA assays showed that the relative ratio of nuclear to cytoplasmic p65 in kidney samples in the cyclosporine group was up-regulated in comparison with that in the control group (4.33 ± 2.06 vs. 0.83 ± 0.26, respectively), while that in the DHMEQ treatment group was down-regulated in comparison with the cyclosporine group (1.34 ± 0.55 vs. 4.33 ± 2.06, respectively). CONCLUSIONS: Treatment with DHMEQ prevents the development of renal interstitial fibrosis due to chronic cyclosporine nephropathy and maintains the renal function. Source of Funding: None

Role of nuclear factor-kappa B in feline injection site sarcoma

BackgroundChronic inflammation has been implicated in sarcomagenesis. Among various factors, activation of nuclear factor-kappa B (NF-κB) signaling pathway has been documented being able to target genes associated with tumor progression and up-regulate the expression of tumor-promoting cytokines and survival genes in several human solid tumors. Feline injection sites sarcomas (FISS) are malignant entities derived from the mesenchymal origin. The disease has been considered to be associated with vaccine adjuvant, aluminum, which serves as a stimulus continuously inducing overzealous inflammatory and immunologic reactions. To understand the contribution of NF-κB in FISS, detection of activated NF-κB in paraffin-embedded specimens, in vitro establishment of primary cells derived from FISS, and evaluation of the effects of the NF-κB inhibitor, dehydroxymethylepoxyquinomicin (DHMEQ), on primary tumor cells were conducted.ResultsIn this study, nuclear expression of NF-κB p65 was detected in 83.3% of FISS cases and not correlated with tumor grading, sex, and age. Primary cells derived from FISS in three cats exhibiting same immunohistochemical characteristics as their original tumor were successfully established. The NF-κB inhibitor, DHMEQ, was able to prevent nuclear translocation of NF-κB p65, inhibit cell proliferation, migration, and colonization in dosage-dependent manners, and induce cell apoptosis in these primary FISS cells.ConclusionsHigh expression rate of nuclear NF-κB p65 in FISS cases and dose-dependent inhibitory effects on the growth of FISS primary cells treated with NF-κB inhibitor suggested that NF-κB might be a potential molecular therapeutic target for FISS.

M75 UP-REGULATED EXPRESSION OF PUTATIVE ANTIPSYCHOTIC RESPONSE GENES FROM GENOME-WIDE ASSOCIATION STUDIES IN THE MOUSE HIPPOCAMPUS FOLLOWING LONG-TERM OLANZAPINE ADMINISTRATION

This study is aimed to further investigate the anti-atopic dermatitis (AD) activities of dehydroxymethylepoxyquinomicin (DHMEQ) ointment and compare its effect with that of tacrolimus ointment based on the previous study that DHMEQ improves AD-like lesions. AD were induced by 2,4-dinitroclilorobenzene/oxazolone (DNCB/OX) repeatedly on the ears of BABL/C mice while medical tape was additionally used to disrupt stratum corneum in order to exacerbate the lesions. The mice were randomly divided into groups, which are normal, vehicle, DHMEQ (0.1%) and tacrolimus (0.1%). Those in the last two groups were externally applied with DHMEQ ointment and tacrolimus ointment, respectively. The results showed that both of them significantly improved dermatitis symptoms of DNCB/OX-induced AD-like lesions, such as redness, itching, weeping, scaling and thickening of the skin, while reducing epidermis thickness, dermis thickness and the number of mast cells as well, which were examined histopathologically. In contrast with DHMEQ, tacrolimus led to a significant decrease in body weight after long-term application. Both DHMEQ and tacrolimus suppress DNCB-induced increase of serum total IgE and attenuate expression of inflammatory factors IL-4, IL-6, IL-13, IL-1β and interferon (IFN)-γ in the disrupted ear tissues. On the other hand, the mice applied with tacrolimus became obviously irritable, jumping up and down, and inflammatory exudation on the lesioned-skin surface of the mice was remarkably observed. Contrary to the side effects made by tacrolimus, DHMEQ didn't cause any adverse stimulus response. As a conclusion, DHMEQ is safer, milder and more suitable for long-term use than tacrolimus for the treatment of AD-like lesions.

Anti-Inflammatory Effect of Dehydroxymethylepoxyquinomicin, a Nuclear factor–κB Inhibitor, on Endotoxin-Induced Uveitis in Rats In vivo and In vitro

ABSTRACTPurpose: To determine the anti-inflammatory effects of dehydroxymethylepoxyquinomicin (DHMEQ), a nuclear factor-κB (NF-κB) inhibitor, on endotoxin-induced uveitis (EIU) in rats.Methods: EIU was induced by a subcutaneous injection of lipopolysaccharide (LPS) in Lewis rats. DHMEQ was injected intraperitoneally concurrently with the LPS. Aqueous humor was collected 24 h after the LPS injection. Isolated peritoneal exudate cells (PECs) were exposed to LPS with or without DHMEQ to determine the production of TNF-α, IL-6, and MCP-1.Results: DHMEQ significantly reduced the number of infiltrating cells, and the concentrations of proteins, TNF-α, and IL-6 in the aqueous humor. DHMEQ suppressed the production of TNF-α, IL-6, and MCP-1 from PECs. Immunochemistry revealed a reduction in the translocation of the NF-κB p65 into the nuclei in DHMEQ-exposed PECs.Conclusions: The results indicate that DHMEQ has anti-inflammatory effects on EIU and may be a promising agent to treat intraocular inflammation.

Comparison of anti-atopic dermatitis activities between DHMEQ and tacrolimus ointments in mouse model without stratum corneum

This study is aimed to further investigate the anti-atopic dermatitis (AD) activities of dehydroxymethylepoxyquinomicin (DHMEQ) ointment and compare its effect with that of tacrolimus ointment based on the previous study that DHMEQ improves AD-like lesions. AD were induced by 2,4-dinitroclilorobenzene/oxazolone (DNCB/OX) repeatedly on the ears of BABL/C mice while medical tape was additionally used to disrupt stratum corneum in order to exacerbate the lesions. The mice were randomly divided into groups, which are normal, vehicle, DHMEQ (0.1%) and tacrolimus (0.1%). Those in the last two groups were externally applied with DHMEQ ointment and tacrolimus ointment, respectively. The results showed that both of them significantly improved dermatitis symptoms of DNCB/OX-induced AD-like lesions, such as redness, itching, weeping, scaling and thickening of the skin, while reducing epidermis thickness, dermis thickness and the number of mast cells as well, which were examined histopathologically. In contrast with DHMEQ, tacrolimus led to a significant decrease in body weight after long-term application. Both DHMEQ and tacrolimus suppress DNCB-induced increase of serum total IgE and attenuate expression of inflammatory factors IL-4, IL-6, IL-13, IL-1β and interferon (IFN)-γ in the disrupted ear tissues. On the other hand, the mice applied with tacrolimus became obviously irritable, jumping up and down, and inflammatory exudation on the lesioned-skin surface of the mice was remarkably observed. Contrary to the side effects made by tacrolimus, DHMEQ didn't cause any adverse stimulus response. As a conclusion, DHMEQ is safer, milder and more suitable for long-term use than tacrolimus for the treatment of AD-like lesions.

Dehydroxymethylepoxyquinomicin suppresses atopic dermatitis-like lesions in a stratum corneum-removed murine model through NF-κB inhibition

Background: Dehydroxymethylepoxyquinomicin (DHMEQ) is a specific and potent inhibitor of nuclear factor-kappa B (NF-κB) and has been shown to possess promising potential as an anti-inflammation including anti-atopic dermatitis (AD)-like skin lesions.Objective: To further evaluate the activity of DHMEQ in vivo modified AD-like lesion model in BALB/c mice and in vitro AD-like lesion cell model in human keratinocytes.Materials and methods: In this study, in vivo modified AD-like lesion model in BALB/c mice was chronically induced by the repetitive and alternative application of 2,4-dinitrochlorobenzene (DNCB) and oxazolone (OX) on ears, and stratum corneum of the ear skin was additionally stripped off with surgical tapes before each challenge with DNCB/OX. Moreover, in vitro AD-like lesion cell model in human keratinocytes (HaCaT) achieved by stimulating HaCaT cells with tumor necrosis factor (TNF)-α plus interferon (IFN)-γ was used to investigate mechanisms of the action.Results: The lesions derived from the stratum corneum-removed AD-like lesion model reaches to peak as well as DHMEQ arrives to its efficacy a week earlier than the data previously obtained from the common AD-like lesion model. Results showed that the drug reduced the ear thickness, epidermal thickness, mast cell infiltration, and gene expressions of interleukin (IL)-4, IL-13, and interferon (IFN)-γ in ear tissues. It significantly inhibited the expression of cytokines IL-6 and IL-1β, chemokines thymus and activation-regulated chemokine (TARC)/CCL17, and macrophage-derived chemokine (MDC)/CCL22 in the stimulated HaCaT cells.Discussion and conclusion: This study indicated that the action of DHMEQ’s anti-AD like lesions might be related to its inhibition on NF-κB.

Antineoplastic Effects of NF-κB Inhibition by DHMEQ (Dehydroxymethylepoxyquinomicin) Alone and in Co-treatment with Radio-and Chemotherapy in Medulloblastoma Cell Lines.

NF-κB is a transcription factor involved in the transcriptional regulation of a large number of genes related to tumorigenesis in several cancer cell types, and its inhibition has been related to anticancer effect. DHMEQ (Dehydroxymethylepoxyquinomicin) is a compound that blocks the translocation of NF-κB from the cytoplasm to the nucleus, thus inhibiting its activity as a transcriptional activator. Several studies have shown the antineoplastic effects of DHMEQ in numerous tumor types, however, there are no surveys that tested their effects in MB. The aim of the present study was to evaluate the effects of DHMEQ as NF-κB inhibitor in pediatric MB cell lines. We used the UW402, UW473 and ONS-76 medulloblastoma (MB) cell lines to verify the effect of DHMEQ on proliferation, clonogenic capacity, apoptosis, cell invasion and migration, and evaluated the effect of the combination with other drugs and the potential as a radiosensitizator. A significant decrease in the cell growth, a strong inhibition of the clonogenic capacity, migration and cell invasion was observed after NF-κB inhibition in the three MB cell lines. Conversely, increased level of apoptosis rates were demonstrated. Additionally, treatments with DHMEQ combined with other chemotherapeutic agents were synergic in most points, and a strong radiosensitization by this compound was observed in the three MB cell lines. DHMEQ has potential antitumor effect on MB cells, and it may be considered a new therapeutic agent to improve treatment approaches in MB.

Microenvironmental stromal cells abrogate NF-κB inhibitor-induced apoptosis in chronic lymphocytic leukemia.

Nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) is known to play an important role in the pathogenesis of chronic lymphocytic leukemia (CLL). Several NF-κB inhibitors were shown to successfully induce apoptosis of CLL cells in vitro. Since the microenvironment is known to be crucial for the survival of CLL cells, herein, we tested whether NF-κB inhibition may still induce apoptosis in these leukemic cells in the presence of protective stromal interaction. We used the specific NF-κB inhibitor dehydroxymethylepoxyquinomicin (DHMEQ). Microenvironmental support was mimicked by co-culturing CLL cells with bone marrow-derived stromal cell lines (HS-5 and M2-10B4). NF-κB inhibition by DHMEQ in CLL cells could be confirmed in both the monoculture and co-culture setting. In line with previous reports, NF-κB inhibition induced apoptosis in the monoculture setting by activating the intrinsic apoptotic pathway resulting in poly (ADP-ribose) polymerase (PARP)-cleavage; however, it was unable to induce apoptosis in leukemic cells co-cultured with stromal cells. Similarly, small interfering ribonucleic acid (siRNA)-mediated RELA downregulation induced apoptosis of CLL cells cultured alone, but not in the presence of supportive stromal cells. B-cell activating factor (BAFF) was identified as a microenvironmental messenger potentially protecting the leukemic cells from NF-κB inhibition-induced apoptosis. Finally, we show improved sensitivity of stroma-supported CLL cells to NF-κB inhibition when combining the NF-κB inhibitor with the SYK inhibitor R406 or the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, agents known to inhibit the stroma-leukemia crosstalk. We conclude that NF-κB inhibitors are not promising as monotherapies in CLL, but may represent attractive therapeutic partners for ibrutinib and R406.

External application of NF-κB inhibitor DHMEQ suppresses development of atopic dermatitis-like lesions induced with DNCB/OX in BALB/c mice

Context: Dehydroxymethylepoxyquinomicin (DHMEQ) which is originally developed as an analog of antibiotic epoxyquinomicin C is a specific and potent inhibitor of NF-κB and has been shown to possess promising potential as an anti-inflammatory and anti-tumor agent.Objective: This study examines DHMEQ’s effect on therapeutic potential for atopic dermatitis (AD)-like lesions.Materials and methods: AD lesions were chronically induced by the repetitive and alternative application of 2,4-dinitrochlorobenzene (DNCB) and oxazolone (OX) on ears in BALB/c mice. The mice were then externally treated with DHMEQ ointment. Macroscopic and microscopic changes of the skin lesions were observed and recorded.Results: DHMEQ inhibited ear swelling and relieved clinical symptoms of the AD-like lesions induced by DNCB/OX in BALB/c mice. Histopathology examination illustrated that it significantly decreased DNCB/OX-induced epidermal thickness, the infiltration of inflammatory cells, and the count of mast cell. The elevated level of immunoglobulin E (IgE) in serum and the mRNA levels of interferon γ (IFN-γ), interleukin 4 (IL-4) and IL-13 in the ear tissues, were also suppressed by DHMEQ.Discussion and conclusion: This study indicated that DHMEQ would be useful for the treatment of AD.