Analysis of expression of nuclear factor kappa B (NF-kappa B) in multiple myeloma: downregulation of NF-kappa B induces apoptosis

Celastrol as an emerging anticancer agent: Current status, challenges and therapeutic strategies

Celastrol is a pentacyclic triterpenoid extracted from the traditional Chinese medicine Tripterygium wilfordii Hook F., which has multiple pharmacological activities. In particular, modern pharmacological studies have demonstrated that celastrol exhibits significant broad-spectrum anticancer activities in the treatment of a variety of cancers, including lung cancer, liver cancer, colorectal cancer, hematological malignancies, gastric cancer, prostate cancer, renal carcinoma, breast cancer, bone tumor, brain tumor, cervical cancer, and ovarian cancer. Therefore, by searching the databases of PubMed, Web of Science, ScienceDirect and CNKI, this review comprehensively summarizes the molecular mechanisms of the anticancer effects of celastrol. According to the data, the anticancer effects of celastrol can be mediated by inhibiting tumor cell proliferation, migration and invasion, inducing cell apoptosis, suppressing autophagy, hindering angiogenesis and inhibiting tumor metastasis. More importantly, PI3K/Akt/mTOR, Bcl-2/Bax-caspase 9/3, EGFR, ROS/JNK, NF-κB, STAT3, JNK/Nrf2/HO-1, VEGF, AR/miR-101, HSF1-LKB1-AMPKα-YAP, Wnt/β-catenin and CIP2A/c-MYC signaling pathways are considered as important molecular targets for the anticancer effects of celastrol. Subsequently, studies of its toxicity and pharmacokinetic properties showed that celastrol has some adverse effects, low oral bioavailability and a narrow therapeutic window. In addition, the current challenges of celastrol and the corresponding therapeutic strategies are also discussed, thus providing a theoretical basis for the development and application of celastrol in the clinic.

Epipolythiodioxopiperazine-Based Natural Products: Building Blocks, Biosynthesis and Biological Activities

Epipolythiodioxopiperazines (ETPs) are fungal secondary metabolites that share a 2,5-diketopiperazine scaffold built from two amino acids and bridged by a sulfide moiety. Modifications of the core and the amino acid side chains, for example by methylations, acetylations, hydroxylations, prenylations, halogenations, cyclizations, and truncations create the structural diversity of ETPs and contribute to their biological activity. However, the key feature responsible for the bioactivities of ETPs is their sulfide moiety. Over the last years, combinations of genome mining, reverse genetics, metabolomics, biochemistry, and structural biology deciphered principles of ETP production. Sulfurization via glutathione and uncovering of the thiols followed by either oxidation or methylation crystallized as fundamental steps that impact expression of the biosynthesis cluster, toxicity and secretion of the metabolite as well as self-tolerance of the producer. This article showcases structure and activity of prototype ETPs such as gliotoxin and discusses the current knowledge on the biosynthesis routes of these exceptional natural products.

MYD88L265P and CD79B double mutations type (MCD type) of diffuse large B-cell lymphoma: mechanism, clinical characteristics, and targeted therapy

MYD88/CD79B-mutated (MCD) genotype is a genetic subgroup of diffuse large B-cell lymphoma (DLBCL) with the co-occurrence of MYD88^L265P and CD79B mutations. MCD genotype is characterized by poor prognosis and extranodal involvement especially in immune-privileged sites. MCD model is dominated by activated B-cell (ABC)-like subtype of DLBCLs. It is generally accepted that the pathogenesis of MCD DLBCL mainly includes chronic active B-cell receptor (BCR) signaling and oncogenic MYD88 mutations, which drives pathological nuclear factor kappa B (NF-κB) activation in MCD lymphoid malignancies. CD79B and MYD88^L265P mutations are frequently and contemporaneously founded in B-cell malignancies. The collaboration of the two mutations may explain the unique biology of MCD. Meanwhile, standard immunochemotherapy combine with different targeted therapies worth further study to improve the prognosis of MCD, according to genetic, phenotypic, and clinical features of MCD type. In this review, we systematically described mechanism, clinical characteristics, and targeted therapy of MCD DLBCL.

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.

An exonuclease protection and CRISPR/Cas12a integrated biosensor for the turn-on detection of transcription factors in cancer cells

Transcription factors (TFs) are critical proteins that regulate the expression of genes, and the abnormal change of TFs levels is directly related to physical dysfunctions. Herein, we developed a clustered regularly interspaced short palindromic repeats (CRISPR)-based biosensor for the measurement of TFs level with the assistance of exonuclease protection assay. A dsDNA (activator) with the ability to activate Cas12a was engineered to contain TFs binding domain, and the binding between TFs and the activator can protect the dsDNA from being digested by exonuclease III (Exo III). The reserved activator then triggered a CRISPR/Cas12a reporting reaction to produce fluorescent signal for detection. In the detection of nuclear factor-kappa B (NF-κB) p50 subunit, the limit of detection of 0.2 pM and limit of quantification of 0.6 pM were obtained respectively, and the performance of this biosensor has been challenged by cell nucleoprotein extracts. Additionally, this method can be applied in the screening and evaluation of TFs inhibitors, calculating the IC50 of oridonin. Integrating merits including high sensitivity, low cost, and good portability, this method may enrich the arsenal for TFs-related applications.

Cell signaling pathways as molecular targets to eliminate AML stem cells

Acute myeloid leukemia (AML) remains the most lethal of leukemias and a small population of cells called leukemic stem cells (LSCs) has been associated with disease relapses. Some cell signaling pathways play an important role in AML survival, proliferation and self-renewal properties and are abnormally activated or suppressed in LSCs. This includes the NF-κB, Wnt/β-catenin, Hedgehog, Notch, EGFR, JAK/STAT, PI3K/AKT/mTOR, TGF/SMAD and PPAR pathways. This review aimed to discuss these pathways as molecular targets for eliminating AML LSCs. Herein, inhibitors/activators of these pathways were summarized as a potential new anti-AML therapy capable of eliminating LSCs to guide future researches. The clinical use of cell signaling pathways data can be useful to enhance the anti-AML therapy.

Potent Activity of an Anti-ICAM1 Antibody-Drug Conjugate against Multiple Myeloma

PURPOSE

New therapies have changed the outlook for patients with multiple myeloma, but novel agents are needed for patients who are refractory or relapsed on currently approved drug classes. Novel targets other than CD38 and BCMA are needed for new immunotherapy development, as resistance to daratumumab and emerging anti-BCMA approaches appears inevitable. One potential target of interest in myeloma is ICAM1. Naked anti-ICAM1 antibodies were active in preclinical models of myeloma and safe in patients, but showed limited clinical efficacy. Here, we sought to achieve improved targeting of multiple myeloma with an anti-ICAM1 antibody-drug conjugate (ADC).

EXPERIMENTAL DESIGN

Our anti-ICAM1 human mAb was conjugated to an auristatin derivative, and tested against multiple myeloma cell lines in vitro, orthotopic xenografts in vivo, and patient samples ex vivo. The expression of ICAM1 was also measured by quantitative flow cytometry in patients spanning from diagnosis to the daratumumab-refractory state.

RESULTS

The anti-ICAM1 ADC displayed potent anti-myeloma cytotoxicity in vitro and in vivo. In addition, we have verified that ICAM1 is highly expressed on myeloma cells and shown that its expression is further accentuated by the presence of bone marrow microenvironmental factors. In primary samples, ICAM1 is differentially overexpressed on multiple myeloma cells compared with normal cells, including daratumumab-refractory patients with decreased CD38. In addition, ICAM1-ADC showed selective cytotoxicity in multiple myeloma primary samples.

CONCLUSIONS

We propose that anti-ICAM1 ADC should be further studied for toxicity, and if safe, tested for clinical efficacy in patients with relapsed or refractory multiple myeloma.

Cytokine-Mediated Dysregulation of Signaling Pathways in the Pathogenesis of Multiple Myeloma

Multiple myeloma (MM) is a hematologic disorder of B lymphocytes characterized by the accumulation of malignant plasma cells (PCs) in the bone marrow. The altered plasma cells overproduce abnormal monoclonal immunoglobulins and also stimulate osteoclasts. The host’s immune system and microenvironment are of paramount importance in the growth of PCs and, thus, in the pathogenesis of the disease. The interaction of MM cells with the bone marrow (BM) microenvironment through soluble factors and cell adhesion molecules causes pathogenesis of the disease through activation of multiple signaling pathways, including NF-κβ, PI3K/AKT and JAK/STAT. These activated pathways play a critical role in the inhibition of apoptosis, sustained proliferation, survival and migration of MM cells. Besides, these pathways also participate in developing resistance against the chemotherapeutic drugs in MM. The imbalance between inflammatory and anti-inflammatory cytokines in MM leads to an increased level of pro-inflammatory cytokines, which in turn play a significant role in dysregulation of signaling pathways and proliferation of MM cells; however, the association appears to be inadequate and needs more research. In this review, we are highlighting the recent findings on the roles of various cytokines and growth factors in the pathogenesis of MM and the potential therapeutic utility of aberrantly activated signaling pathways to manage the MM disease.

NFKB2 gene expression in patients with peptic ulcer diseases and gastric cancer

Gastric cancer is one of the most common worldwide types of cancer. It is a multifactorial disease and both environmental and genetic factors play an important role in its etiology. Evaluation of the relative expression level of NFKB2 gene in two groups of patients: peptic ulcer and gastric cancer and its role in the pathomechanism of these diseases was the aim of this study. RNA was isolated from: 79 samples of peptic ulcer, 22 gastric cancer and 11 control tissue. The real-time PCR technique was used to study the expression of NFKB2 gene. The relative expression level of NFKB2 gene was a variable in all three studied groups. The relative NFKB2 gene expression depends on the type of a disease. Peptic ulcer cases showed the increased relative NFKB2 gene expression to control group (p = 0.0000). Cancer cases presented decreased relative NFKB2 gene expression to normal stomach tissue (p = 0.0183). There are statistically important differences in the investigated gene expression between peptic ulcer, where the expression level is higher comparing to gastric cancer and control tissue which confirmed that such an activation is connected with an inflammatory process. The relative expression level of NFKB2 is decreased in cancer cases as opposed to control tissue and peptic ulcer cases which could suggest that during carcinogenesis of gastric cancer inhibition of NF-kB pathway takes place which could be a promising factor for patients.

Inhibition of miR-221 alleviates LPS-induced acute lung injury via inactivation of SOCS1/NF-κB signaling pathway

The role of inflammation response has been well documented in the development of acute lung injury (ALI). However, little is known about the functions of miRNAs in the regulation of inflammation in ALI. The aim of this study was to explore the effects of miRNAs in the regulation of inflammation in ALI and to elucidate the biomolecular mechanisms responsible for these effects. The expression profiles of miRNAs in lung tissues from lipopolysaccharide (LPS)-induced ALI mice model were analyzed using a microarray. It was observed that microRNA-221-3p (miR-221) was significantly increased in lung tissues in ALI mice. The inhibition of miR-221 attenuated lung injury including decreased lung W/D weight ratio and lung permeability and survival rates of ALI mice, as well as apoptosis, whereas its agomir-mediated upregulation exacerbated the lung injury. Concomitantly, miR-221 inhibition significantly reduced LPS-induced pulmonary inflammation, while LPS-induced pulmonary inflammation was aggravated by miR-221 upregulation. Of note, suppressor of cytokine signaling-1 (SOCS1), an effective suppressor of the NF-κB signaling pathway, was found to be a direct target of miR-221 in RAW264.7 cells. Overexpression of SOCS1 by pcDNA-SOCS1 plasmids markedly reversed the miR-221 inhibition-mediated inhibitory effects on inflammation and apoptosis in LPS-treated RAW264.7 cells. Finally, it was found that miR-221 inhibition suppressed LPS induced the activation of the NF-κB signaling pathway, as demonstrated by downregulation of phosphorylated-IκBα, p-p65 and upregulation of IκBα, whilst miR-221 overexpression had an opposite result in ALI mice. Our findings demonstrate that inhibition of miR-221 can alleviate LPS-induced inflammation via inactivation of SOCS1/NF-κB signaling pathway in ALI mice.

Effects of Systematic Shortening of Noncovalent C8 Side Chain on the Cytotoxicity and NF-κB Inhibitory Capacity of Pyrrolobenzodiazepines (PBDs)

The systematic shortening of the noncovalent element of a C8-linked pyrrolobenzodiazepine (PBD) conjugate (13) led to the synthesis of a 19-member library of C8-PBD monomers. The critical elements of 13, which were required to render the molecule cytotoxic, were elucidated by an annexin V assay. The effects of shortening the noncovalent element of the molecule on transcription factor inhibitory capacity were also explored through an enzyme-linked immunosorbent assay-based measurement of nuclear NF-κB upon exposure of JJN-3 cells to the synthesized molecules. Although shortening the noncovalent interactive element of 13 had a less than expected effect upon compound cytotoxicity due to reduced DNA interaction, the transcription factor inhibitory capacity of the molecule was notably altered. This study suggests that a relatively short noncovalent side chain at the C8 position of PBD is sufficient to confer cytotoxicity. The shortened PBD monomers provide a new ADC payload scaffold because of their potent cytotoxicity and drug-like properties.

Celecoxib attenuates hepatocellular proliferative capacity during hepatocarcinogenesis by modulating a PTEN/NF-κB/PRL-3 pathway

Although the efficacy of celecoxib on various cancer cell behaviors, including aberrant proliferation, in cultured hepatocellular carcinoma (HCC) cells has been demonstrated, whether celecoxib regulates cell proliferation by targeting PRL-3-associated signaling transduction during hepatocarcinogenesis in vivo has been incompletely studied. Here, we investigate the anti-proliferative efficacy of celecoxib in a rapid HCC mouse model established by hydrodynamic transfection of activated AKT and c-Met proto-oncogenes. The results show that celecoxib is effective at delaying the malignant transformation of hepatocytes by reducing the protein expression of Ki67, Cyclin D1 and c-Myc in the AKT/c-Met HCC-bearing mice. Mechanistically, celecoxib increases the protein expression of PTEN and suppresses the protein expression of NF-κB and PRL-3 in the liver of the HCC mice. Using PTEN-silenced and LPS-stimulated approaches in vitro, a mechanism by which celecoxib regulates a PTEN/NF-κB/PRL-3 pathway in HCC cells was illuminated. Altogether, our study demonstrates that celecoxib attenuates the hepatocellular proliferative capacity during hepatocarcinogenesis, which is probably attributable to its regulation of the PTEN/NF-κB/PRL-3 pathway.

Celecoxib modulates the PTEN/NF-κB/PRL-3 pathway during hepatocarcinogenesis in vivo.

The contribution of immune activation and accelerated aging in multiple myeloma occurring in HIV-infected population

: The widespread use of antiretroviral treatment results in a significant improvement in immunological condition of people living with HIV (PLWH) who nevertheless experience a significantly increased risk to develop non-Hodgkin lymphoma compared with the general population. Despite many literature observations regarding multiple myeloma in PLWH, a consensus on its relevance in HIV infection does not exist. A number of large population studies on multiple myeloma in PLWH gave contrasting results, fluctuating from increased standardized incidence ratios to the lack of observed cases of multiple myeloma. Use of antiretroviral treatment, in this context, seems to induce a slight reduction of standardized incidence ratio, although with a partial effect, especially in young patients. However, a high variability in clinical onset has been described in different reports: the only common feature of multiple myeloma in PLWH is an atypical presentation as compared with general population, with a worse prognosis in case of uncontrolled HIV infection. We identified three pathogenetic steps in the complex scenario of multiple myeloma in PLWH: first, antigenic trigger; second, persistent T cell deficiency/dysfunction; third, altered regulation of B cells. All these pathogenetic steps play a role in immunological dysregulation, leading to B cell abnormalities and hyperactivation and, finally, resulting in the development of lymphoid malignancies. HIV has a role in each one of these three steps, due to its ability to trigger and dysregulate immune system. We hypothesize that HIV could be closely implicated in the multiple myeloma development in PLWH by accelerating the carcinogenesis events in a complex and only partially understood early aging process.

Detecting transcription factors with allosteric DNA-Silver nanocluster switches

Sensitive and efficient detection of protein markers, such as transcription factors (TFs), is an important issue in postgenomic era. In this paper, we report a DNA nanodevice, allosteric DNA-silver nanocluster switches (AgSwitches), for TFs detection. The mechanism of this nanodevice is based on the binding-induced allostery whereby the binding between AgSwitches and TFs alters the conformation of AgSwitches. This alteration brings DNA-silver nanocluster (DNA-AgNCs) and guanine-rich enhancer sequences (GRS) into close proximity, generating fluorescent enhancement for quantifications. Our results revealed that the sequence design of AgSwitches can be rationally optimized according to stimulated free energy, and we demonstrated that this method can not only be used for detecting TFs in nuclear extracts of cells, but also be developed as a tool for screening inhibitors of TFs. Overall, this work expanded the category allosteric DNA nanodevices by first introducing DNA-AgNCs into this area, and the obtained method was efficient for TFs-related investigations.

Lidanpaidu prescription alleviates lipopolysaccharide-induced acute kidney injury by suppressing the NF-κB signaling pathway

The Lidanpaidu Prescription (LDP), a hospital preparation, composed of Chinese classical preparations, has been reported to have antiendotoxin, anticoagulant and other effects. However, its therapeutic effect on lipopolysaccharide (LPS)-induced acute kidney injury (AKI) and the mechanisms remain unclear. Therefore, we administered LPD pretreatment at different doses to examine the protective effects and mechanisms in LPS-induced AKI in mice. The kidney injury induced by LPS was assessed by histological examination. ELISA was used to detect the levels of inflammatory cytokines. The mRNA expression of the inflammatory genes IKKβ and TNF-α in kidney tissues was assessed by RT-PCR. Finally, Western blot was performed to assess the NF-κB signaling pathway related proteins, and the nuclear translocation of NF-kB P65 was detected by immunofluorescence laser confocal microscopy. The findings suggested that LDP significantly improved at 48 h animal survival (66.7%), compared with the LPS group (26.7%), determined by a Kaplan-Meier analysis. LDP attenuated the kidney histopathological changes induced by LPS and decreased the inflammatory cytokine levels in serum and renal tissue. Moreover, LDP markedly inhibited the expression of inflammatory genes and suppressed the activation of relevant proteins in the nucleus. In summary, these findings suggest that LDP reduces LPS-induced AKI via a mechanism related to the suppression of the NF-κB signaling pathway.

Celastrol Attenuates the Invasion and Migration and Augments the Anticancer Effects of Bortezomib in a Xenograft Mouse Model of Multiple Myeloma

Several lines of evidence have demonstrated that deregulated activation of NF-κB plays a pivotal role in the initiation and progression of a variety of cancers including multiple myeloma (MM). Therefore, novel molecules that can effectively suppress deregulated NF-κB upregulation can potentially reduce MM growth. In this study, the effect of celastrol (CSL) on patient derived CD138+ MM cell proliferation, apoptosis, cell invasion, and migration was investigated. In addition, we studied whether CSL can potentiate the apoptotic effect of bortezomib, a proteasome inhibitor in MM cells and in a xenograft mouse model. We found that CSL significantly reduced cell proliferation and enhanced apoptosis when used in combination with bortezomib and upregulated caspase-3 in these cells. CSL also inhibited invasion and migration of MM cells through the suppression of constitutive NF-κB activation and expression of downstream gene products such as CXCR4 and MMP-9. Moreover, CSL when administered either alone or in combination with bortezomib inhibited MM tumor growth and decreased serum IL-6 and TNF-α levels. Overall, our results suggest that CSL can abrogate MM growth both in vitro and in vivo and may serve as a useful pharmacological agent for the treatment of myeloma and other hematological malignancies.

NF-κB Activation in Lymphoid Malignancies: Genetics, Signaling, and Targeted Therapy

The NF-κB transcription factor family plays a crucial role in lymphocyte proliferation and survival. Consequently, aberrant NF-κB activation has been described in a variety of lymphoid malignancies, including diffuse large B-cell lymphoma, Hodgkin lymphoma, and adult T-cell leukemia. Several factors, such as persistent infections (e.g., with Helicobacter pylori), the pro-inflammatory microenvironment of the cancer, self-reactive immune receptors as well as genetic lesions altering the function of key signaling effectors, contribute to constitutive NF-κB activity in these malignancies. In this review, we will discuss the molecular consequences of recurrent genetic lesions affecting key regulators of NF-κB signaling. We will particularly focus on the oncogenic mechanisms by which these alterations drive deregulated NF-κB activity and thus promote the growth and survival of the malignant cells. As the concept of a targeted therapy based on the mutational status of the malignancy has been supported by several recent preclinical and clinical studies, further insight in the function of NF-κB modulators and in the molecular mechanisms governing aberrant NF-κB activation observed in lymphoid malignancies might lead to the development of additional treatment strategies and thus improve lymphoma therapy.

Kinase inhibitors as potential agents in the treatment of multiple myeloma

Recent years have witnessed a dramatic increase in the number of therapeutic options available for the treatment of multiple myeloma (MM) - from immunomodulating agents to proteasome inhibitors to histone deacetylase (HDAC) inhibitors and, most recently, monoclonal antibodies. Used in conjunction with autologous hematopoietic stem cell transplantation, these modalities have nearly doubled the disease's five-year survival rate over the last three decades to about 50%. In spite of these advances, MM still is considered incurable as resistance and relapse are common. While small molecule protein kinase inhibitors have made inroads in the therapy of a number of cancers, to date their application to MM has been less than successful. Focusing on MM, this review examines the roles played by a number of kinases in driving the malignant state and the rationale for target development in the design of a number of kinase inhibitors that have demonstrated anti-myeloma activity in both in vitro and in vivo xenograph models, as well as those that have entered clinical trials. Among the targets and their inhibitors examined are receptor and non-receptor tyrosine kinases, cell cycle control kinases, the PI3K/AKT/mTOR pathway kinases, protein kinase C, mitogen-activated protein kinase, glycogen synthase kinase, casein kinase, integrin-linked kinase, sphingosine kinase, and kinases involved in the unfolded protein response.

Identification and application of anti-inflammatory compounds screening system based on RAW264.7 cells stably expressing NF-κB-dependent SEAP reporter gene

BACKGROUND

NF-κB is one of the key transcription factors in the inflammatory response, transactivates a series of pro-inflammatory genes and is therefore regarded as an important target for anti-inflammatory drug screening.

METHOD

We recombined the reporter gene vector with inserting the "neo" transcript into the vector pNF-κB-SEAP, made the reporter gene vector stable in a eukaryotic cell line. The recombinant reporter gene vector we named pNF-κB-SEAP-Neo was transfected into RAW264.7. We selected the transfected RAW264.7 cell line with G418 for 15 days and then get RAW264.7 cells stably expressing NF-κB-dependent SEAP named as RAW264.7-pNF-κB-SEAP cells. We treated the RAW264.7-pNF-κB-SEAP cells with NF-κB agonists as LPS, PolyI:C and TNF-α, NF-κB inhibitor as PDTC and BAY117085, in different concentrations and time points and tested the expression of the SEAP, constructed the drug screening system on the base of the RAW264.7-pNF-κB-SEAP cell line. 130 chemicals were screened with the drug screening system we constructed and one of these chemicals numbered w10 was found could inhibit the NF-κB significantly. At last, we verified the inhibition of w10 to expression of genes promoted with NF-κB in HepG2 and Hela, and to migration of Hela.

RESULT

In this study, we established a drug screening system based on RAW264.7 cells that stably expressed the NF-κB-dependent, SEAP reporter gene. To develop a standard method for drug screening using this reporter-gene cell line, the test approach of SEAP was optimized and basic conditions for drug screening were chosen. This included the initial cell number inoculated in a 96-well plate, the optimum agonist, inhibitor of NF-κB pathway and their concentrations during screening. Subsequently, 130 newly synthesized compounds were screened using the stable reporter-gene cell line. The anti-inflammatory effects of the candidate compounds obtained were further verified in 2 cancer cell lines. The results indicated that compound W10 (methyl 4-(4-(prop-2-yn-1-ylcarbamoyl) phenylcarbamoyl) benzoate) significantly inhibited SEAP production under the screening conditions. Further results confirmed that the precursor compound significantly inhibited the transcription of NF-κB target genes.

CONCLUSION

In conclusion, RAW264.7 cells, stably expressing the NF-κB-dependent SEAP-reporter gene, may provide a new, feasible, and efficient cellular drug-screening system.

Small Molecule Inhibition of Rab7 Impairs B Cell Class Switching and Plasma Cell Survival To Dampen the Autoantibody Response in Murine Lupus

IgG autoantibodies mediate pathology in systemic lupus patients and lupus-prone mice. In this study, we showed that the class-switched IgG autoantibody response in MRL/Fas^lpr/lpr and C57/Sle1Sle2Sle2 mice was blocked by the CID 1067700 compound, which specifically targeted Ras-related in brain 7 (Rab7), an endosome-localized small GTPase that was upregulated in activated human and mouse lupus B cells, leading to prevention of disease development and extension of lifespan. These were associated with decreased IgG-expressing B cells and plasma cells, but unchanged numbers and functions of myeloid cells and T cells. The Rab7 inhibitor suppressed T cell-dependent and T cell-independent Ab responses, but it did not affect T cell-mediated clearance of Chlamydia infection, consistent with a B cell-specific role of Rab7. Indeed, B cells and plasma cells were inherently sensitive to Rab7 gene knockout or Rab7 activity inhibition in class switching and survival, respectively, whereas proliferation/survival of B cells and generation of plasma cells were not affected. Impairment of NF-κB activation upon Rab7 inhibition, together with the rescue of B cell class switching and plasma cell survival by enforced NF-κB activation, indicated that Rab7 mediates these processes by promoting NF-κB activation, likely through signal transduction on intracellular membrane structures. Thus, a single Rab7-inhibiting small molecule can target two stages of B cell differentiation to dampen the pathogenic autoantibody response in lupus.

Pure total flavonoids from Citrus paradisi Macfadyen act synergistically with arsenic trioxide in inducing apoptosis of Kasumi-1 leukemia cells in vitro

To investigate the potential effects of pure total flavonoid compounds (PTFCs) from Citrus paradisi Macfadyen separately or combined with arsenic trioxide on the proliferation of human myeloid leukemia cells and the mechanisms underlying the action of PTFCs. The effects of PTFCs separately or combined with arsenic trioxide on the proliferation and apoptosis of leukemia cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), fluorescence microscopy, and flow cytometry. Their effects on the expression levels of apoptosis-related regulators were determined by Western blot assay. PTFCs combined with arsenic trioxide significantly inhibited the growth of Kasumi-1 cells, and apoptosis was confirmed by flow cytometry analysis. Hoechst 33258 staining showed more significant morphological changes and more apoptosis following the combined treatment. Western blots showed changes in the expression of genes for poly ADP-ribose polymerase (PARP), caspase 3/9, and P65. The results indicated that PTFCs separately or combined with arsenic trioxide inhibited proliferation of leukemia cells in vitro and induced their apoptosis by modulating the expression of apoptosis-related regulator genes.

Dimethyl Fumarate Reduces Inflammatory Responses in Experimental Colitis

BACKGROUND AND AIMS

Fumaric acid esters have been proven to be effective for the systemic treatment of psoriasis and multiple sclerosis. We aimed to develop a new treatment for colitis.

METHODS

We investigated the effect of dimethylfumarate [DMF, 10-30-100mg/kg] on an experimental model of colitis induced by dinitrobenzene sulphuric acid [DNBS]. We also evaluated the therapeutic activity of 7 weeks' treatment with DMF [30mg/kg] on 9-week-old IL-10KO mice that spontaneously develop a T helper-1 [Th1]-dependent chronic enterocolitis after birth, that is fully established at 8-10 weeks of age. The mechanism of this pharmacological potential of DMF [10 μM] was investigated in colonic epithelial cell monolayers [Caco-2] exposed to H2O2. The barrier function was evaluated by the tight junction proteins.

RESULTS

The treatment with DMF significantly reduced the degree of haemorrhagic diarrhoea and weight loss caused by administration of DNBS. DMF [30 and 100mg/kg] also caused a substantial reduction in the degree of colon injury, in the rise in myeloperoxidase [MPO] activity, and in the increase in tumour necrosis factor [TNF]-α expression, as well as in the up-regulation of ICAM-1 caused by DNBS in the colon. Molecular studies demonstrated that DMF impaired NF-κB signalling via reduced p65 nuclear translocalisation. DMF induced a stronger antioxidant response as evidenced by a higher expression of Mn-superoxide dismutase. Moreover, DMF protected human intestinal epithelial cells against H2O2-induced barrier dysfunction, restoring ZO-1 occludin expression, via the HO-1 pathway.

CONCLUSIONS

DMF treatment reduces the degree of colitis caused by DNBS. We propose that DMF treatment may be useful in the treatment of inflammatory bowel disease.

Mangiferin induces apoptosis in multiple myeloma cell lines by suppressing the activation of nuclear factor kappa B-inducing kinase

Mangiferin is a naturally occurring glucosyl xanthone, which induces apoptosis in various cancer cells. However, the molecular mechanism underlying mangiferin-induced apoptosis has not been clarified thus far. Therefore, we examined the molecular mechanism underlying mangiferin-induced apoptosis in multiple myeloma (MM) cell lines. We found that mangiferin decreased the viability of MM cell lines in a concentration-dependent manner. We also observed an increased number of apoptotic cells, caspase-3 activation, and a decrease in the mitochondrial membrane potential. In addition, mangiferin inhibited the nuclear translocation of nuclear factor kappa B (NF-κB) and expression of phosphorylated inhibitor kappa B (IκB) and increased the expression of IκB protein, whereas no changes were observed in the phosphorylation levels of extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun N-terminal protein kinase 1/2 (JNK1/2), and mammalian target of rapamycin (mTOR). The molecular mechanism responsible for mangiferin-induced inhibition of nuclear translocation of NF-κB was a decrease in the expression of phosphorylated NF-κB-inducing kinase (NIK). Moreover, mangiferin decreased the expression of X-linked inhibitor of apoptosis protein (XIAP), survivin, and Bcl-xL proteins. Knockdown of NIK expression showed results similar to those observed with mangiferin treatment. Our results suggest that mangiferin induces apoptosis through the inhibition of nuclear translocation of NF-κB by suppressing NIK activation in MM cell lines. Our results provide a new insight into the molecular mechanism of mangiferin-induced apoptosis. Importantly, since the number of reported NIK inhibitors is limited, mangiferin, which targets NIK, may be a potential anticancer agent for the treatment of MM.

Analysis of Nucleocytoplasmic Protein Shuttling by Imaging Flow Cytometry

Many intracellular signal transduction events involve the reversible shuttling of proteins between the cytoplasm and the nucleus. Study of these processes requires imaging information on the protein localization in a given cell and a large number of measurements to obtain sufficient statistics on the protein localization in the whole population. The protocol describes method for quantitative imaging flow cytometry analysis of intracellular distribution of NF-kappaB in ARPE-19 cells stained with specific fluorochrome-conjugated antibodies. The described technique alone or in combination with standard flow cytometry methods can be applied to study any protein undergoing translocation from cytoplasm into the nucleus in a variety of cell lines as well as in heterogeneous primary cell populations.

Gliotoxin--bane or boon?

Gliotoxin (GT) is the most important epidithiodioxopiperazine (ETP)-type fungal toxin. GT was originally isolated from Trichoderma species as an antibiotic substance involved in biological control of plant pathogenic fungi. A few isolates of GT-producing Trichoderma virens are commercially marketed for biological control and widely used in agriculture. Furthermore, GT is long known as an immunosuppressive agent and also reported to have anti-tumour properties. However, recent publications suggest that GT is a virulence determinant of the human pathogen Aspergillus fumigatus. This compound is thus important on several counts - it has medicinal properties, is a pathogenicity determinant, is a potential diagnostic marker and is important in biological crop protection. The present article addresses this paradox and the ecological role of GT. We discuss the function of GT as defence molecule, the role in aspergillosis and suggest solutions for safe application of Trichoderma-based biofungicides.

Dysregulation of the NLRP3 inflammasome complex and related cytokines in patients with multiple myeloma

OBJECTIVE

The NLRP3 inflammasome complex, an important regulatory factor of inflammation and cell apoptosis, has attracted considerable attention in the development of tumor. Here, we analyzed the expression and clinical significance of NLRP3 inflammasome complex and related cytokines in patients with multiple myeloma (MM).

METHODS

Peripheral blood and bone marrow of 38 newly diagnosed myeloma patients and 25 age- and gender-matched healthy people were studied. NLRP3 and caspase-1 were analyzed using quantitative real-time polymerase chain reaction and Western blot and IL-1beta, IL-18, RANKL, and OPG were evaluated by enzyme-linked immunosorbent assay.

RESULTS

We showed that aberrant NLRP3 and caspase-1 expression were observed in MM and down-regulated compared with the healthy people. We further demonstrated that NLRP3 mRNA was negatively correlated with beta2-microglobulin and plasma cell percentage in MM. The downstream cytokines IL-18 and sRANKL/OPG in MM patients were higher than that in control group. Moreover, the lower mRNA levels of NLRP3 and caspase-1 were shown to be positively correlated with IL-1beta in newly diagnosed MM patients.

CONCLUSIONS

This study demonstrated that dysregulated expression of NLRP3-caspase-1-IL-1beta axis was observed in patients with MM, suggesting they might be involved in the pathogenesis of MM.

Frequent down regulation of the tumor suppressor gene a20 in multiple myeloma

Multiple myeloma (MM) is a malignant clonal expansion of plasma cells in the bone marrow and belongs to the mature B-cell neoplams. The pathogenesis of MM is associated with constitutive NF-κB activation. However, genetic alterations causing constitutive NF-κB activation are still incompletely understood. Since A20 (TNFAIP3) is a suppressor of the NF-κB pathway and is frequently inactivated in various lymphoid malignancies, we investigated the genetic and epigenetic properties of A20 in MM. In total, of 46 patient specimens analyzed, 3 single base pair exchanges, 2 synonymous mutations and one missense mutation were detected by direct sequencing. Gene copy number analysis revealed a reduced A20 gene copy number in 8 of 45 (17.7%) patients. Furthermore, immunohistochemical staining confirmed that A20 expression correlates with the reduction of A20 gene copy number. These data suggest that A20 contributes to tumor formation in a significant fraction of myeloma patients.

Proteotoxic crisis, the ubiquitin-proteasome system, and cancer therapy

Genomic alterations may make cancer cells more dependent than normal cells on mechanisms of proteostasis, including protein folding and degradation. This proposition is the basis for the clinical use of proteasome inhibitors to treat multiple myeloma and mantle cell lymphoma. However, proteasome inhibitors have not proved effective in treating other cancers, and this has called into question the general applicability of this approach. Here, I consider possible explanations for this apparently limited applicability, and discuss whether inhibiting other broadly acting components of the ubiquitin-proteasome system - including ubiquitin-activating enzyme and the AAA-ATPase p97/VCP - might be more generally effective in cancer therapy.

Dimethyl fumarate induces apoptosis of hematopoietic tumor cells via inhibition of NF-κB nuclear translocation and down-regulation of Bcl-xL and XIAP

Dimethyl fumarate (DMF) is a fumaric acid ester that is used to treat psoriasis and multiple sclerosis. Recently, DMF was found to exhibit anti-tumor effects. However, the molecular mechanisms underlying these effects have not been elucidated. In this study, we investigated the mechanism of DMF-induced apoptosis in different human hematopoietic tumor cell lines. We found that DMF induced apoptosis in different human hematopoietic tumor cell lines but it did not affect the normal human B lymphocyte cell line RPMI 1788. We also observed a concurrent increase in caspase-3 activity and in the number of Annexin-V-positive cells. Furthermore, an examination of the survival signals, which are activated by apoptotic stimuli, revealed that DMF significantly inhibited nuclear factor-κB (NF-κB) p65 nuclear translocation. In addition, DMF suppressed B-cell lymphoma extra-large (Bcl-xL) and X-linked inhibitor of apoptosis (XIAP) expression whereas Bcl-2, survivin, Bcl-2-associated X protein (Bax), and Bim levels did not change. These results indicated that DMF induced apoptosis by suppressing NF-κB activation, and Bcl-xL and XIAP expression. These findings suggested that DMF might have potential as an anticancer agent that could be used in combination therapy with other anticancer drugs for the treatment of human hematopoietic tumors.

Targeting phospho-MARCKS overcomes drug-resistance and induces antitumor activity in preclinical models of multiple myeloma

Multiple myeloma (MM) is incurable in virtually all patients due to the presence of innate and emergent drug-resistance. To identify potential drug resistance mechanisms in MM we used iTRAQ (isobaric tags for relative and absolute quantitation) mass spectrometry to compare protein expression profiles of drug-resistant (RPMI 8226-R5) and sensitive (RPMI 8226-S) isogenic cell lines. We identified selective overexpression of myristoylated alanine-rich C-kinase substrate (MARCKS) in drug-resistant R5 cells. MARCKS overexpression was also observed in several drug-resistant human myeloma cell lines (HMCLs) and in drug-resistant primary MM samples. Functionally, inhibition of MARCKS phosphorylation by enzastaurin or knockdown of the gene by RNAi significantly enhanced the sensitivity of resistant HMCLs and primary MM samples to bortezomib and to other anti-myeloma drugs, providing evidence that MARCKS can modulate drug response. Mechanistically, pMARCKS (phosphorylated form of MARCKS) was found to function as an E2F-1 cofactor to regulate SKP2 transcription. pMARCKS promoted cell-cycle progression by facilitating SKP2 expression, suppressing p27(Kip1) and potentially counteracting drug-induced cell-cycle arrest by promoting Cyclin E/CDK2 activity. Importantly, MARCKS knockdown in combination with bortezomib treatment overcame bortezomib resistance, significantly inhibited tumor growth and prolonged host survival in a MM xenograft model. These data provide a rationale for therapeutic targeting of pMARCKS to improve the outcome of patients with refractory/relapsed MM.

Increased frequency of Mediterranean fever gene variants in multiple myeloma

High frequencies of inherited variants in the Mediterranean fever (MEFV) gene have been identified in patients with multiple myeloma (MM). The sample size of the present pilot study was small, therefore, the actual frequency of inherited variants in the MEFV gene could be investigated in patients with MM. Twenty-eight patients with MM and 65 healthy controls were included in the study. Six heterozygous and one homozygous (E148Q/E148Q) variant was identified in patients with MM. None of the patients had a family history compatible with familial Mediterranean fever. In the healthy control group, 11 heterozygous variants were identified. The difference in the overall frequency of the inherited variants in the MEFV gene between the MM patients and the controls was statistically significant (χ²=4.905; P=0.027). In conclusion, a high frequency of inherited variants in the MEFV gene was identified in patients with MM. Based on the current data, it is hypothesized that the MEFV gene is a cancer susceptibility gene. Additional evidence, such as familial aggregation, monozygotic versus dizygotic twin concordance, and tumors in genetically engineered model organisms, is required in order to support this hypothesis.

Nuclear factor-κB is involved in the protocadherin-10-mediated pro-apoptotic effect in multiple myeloma

The gene encoding protocadherin-10 (PCDH10), a member of the cadherin superfamily, has been recently identified as a tumor suppressor gene (TSG). PCDH10 plays important roles in the apoptosis of tumor cells in some cancer types. However, the exact role of PCDH10 in multiple myeloma (MM) is largely unknown. Increasing evidence has suggested that the activation of nuclear factor-κB (NF-κB) is crucial for apoptosis in myeloma cells. In this study, we investigated the pro-apoptotic effect of PCDH10 on myeloma cells and whether this effect may involve inhibition of the NF-κB pathway. We report here, for the first time to the best of our knowledge, that PCDH10 markedly induces apoptosis of myeloma cells, accompanied by an increase in activated caspase-3 and poly-ADP‑ribose polymerase (PARP) levels, and inhibited expression of anti‑apoptotic proteins. We also demonstrate that PCDH10 inhibits the activation of NF-κB, by inhibiting the expression of the inhibitor of nuclear factor-κB (IκB) kinase subunits (IKKs) and the phosphorylation of IκBα. Moreover, the constitutive NF-κB DNA-binding activity and the expression of the NF-κB‑regulated proteins cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF) and intercellular adhesion molecule 1 (ICAM-1) were inhibited by PCDH10 in MM cells. These results suggest that PCDH10 induces myeloma cell apoptosis, probably by inhibiting the NF-κB pathway.

NF-kappa B modulation is involved in celastrol induced human multiple myeloma cell apoptosis

Celastrol is an active compound extracted from the root bark of the traditional Chinese medicine Tripterygium wilfordii Hook F. To investigate the effect of celastrol on human multiple myeloma cell cycle arrest and apoptosis and explore its molecular mechanism of action. The activity of celastrol on LP-1 cell proliferation was detected by WST-8 assay. The celastrol-induced cell cycle arrest was analyzed by flow cytometry after propidium iodide staining. Nuclear translocation of the nuclear factor kappa B (NF-κB) was observed by fluorescence microscope. Celastrol inhibited cell proliferation of LP-1 myeloma cell in a dose-dependent manner with IC50 values of 0.8817 µM, which was mediated through G1 cell cycle arrest and p27 induction. Celastrol induced apoptosis in LP-1 and RPMI 8226 myeloma cells in a time and dose dependent manner, and it involved Caspase-3 activation and NF-κB pathway. Celastrol down-modulated antiapoptotic proteins including Bcl-2 and survivin expression. The expression of NF-κB and IKKa were decreased after celastrol treatment. Celastrol effectively blocked the nuclear translocation of the p65 subunit and induced human multiple myeloma cell cycle arrest and apoptosis by p27 upregulation and NF-kB modulation. It has been demonstrated that the effect of celastrol on NF-kB was HO-1-independent by using zinc protoporphyrin-9 (ZnPPIX), a selective heme oxygenase inhibitor. From the results, it could be inferred that celastrol may be used as a NF-kB inhibitor to inhibit myeloma cell proliferation.

Modulation of apoptosis-related cell signalling pathways by curcumin as a strategy to inhibit tumor progression

A hallmark of cancer is resistance to apoptosis, with both the loss of proapoptotic signals and the gain of anti-apoptotic mechanisms contributing to tumorigenesis. As inducing apoptosis in malignant cells is one of the most challenging tasks regarding cancer, researchers increasingly focus on natural products to regulate apoptotic signaling pathways. Curcumin, a polyphenolic derivative of turmeric, is a natural compound derived from Curcuma longa, has attracted great interest in the research of cancer during the last half century. Extensive studies revealed that curcumin has chemopreventive properties, which are mainly due to its ability to arrest cell cycle and to induce apoptosis in cancer cells either alone or in combination with chemotherapeutic agents or radiation. The underlying action mechanisms of curcumin are diverse and has not been elucidated so far. By regulating multiple important cellular signalling pathways including NF-κB, TRAIL, PI3 K/Akt, JAK/STAT, Notch-1, JNK, etc., curcumin are known to activate cell death signals and induce apoptosis in pre-cancerous or cancer cells without affecting normal cells, thereby inhibiting tumor progression. Several phase I and phase II clinical trials indicate that curcumin is quite safe and may exhibit therapeutic efficacy. This article reviews the main effects of curcumin on the different apoptotic signaling pathways involved in curcumin induced apoptosis in cancer cells via cellular transduction pathways and provides an in depth assessment of its pharmacological activity in the management of tumor progression.

Plasma cell disorders in HIV-infected patients: epidemiology and molecular mechanisms

Highly active antiretroviral therapy (HAART) has significantly improved the outcome and survival of human immunodeficiency virus (HIV)-infected patients. Subsequently, long-term morbidities including cancer have become of major public health and clinical interest for this patient population. Plasma cell disorders occur at higher incidence in HIV-infected patients; however, the molecular mechanisms driving the plasma cell disease process and the optimal management for these patients remain to be defined. This article provides an up-to-date review of the characteristics and management of HIV-infected patients with plasma cell disorders. We first present 3 cases of plasma cell disorders in HIV-infected patients, ranging from polyclonal hypergammaglobulinemia to symptomatic multiple myeloma. We then discuss the epidemiology, clinical presentation, and management of each of these plasma cell disorders, with an emphasis on the molecular events underlying the progression of plasma cell diseases from monoclonal gammopathy to symptomatic multiple myeloma. We propose a three-step hypothesis for the development of multiple myeloma. Finally, we discuss the use of high dose chemotherapy and autologous hematopoietic stem cell transplantation in the treatment of HIV-infected patients with multiple myeloma. Our review includes the care of HIV-infected patients with plasma cell disorders in the current era of HAART and novel agents available for the treatment of multiple myeloma.

TLR4 antagonist reduces early-stage atherosclerosis in diabetic apolipoprotein E-deficient mice

Although it has been reported that deficiency of toll-like receptor 4 (TLR4) is associated with reduced atherosclerosis in atherosclerosis-prone mice and attenuated pro-inflammatory state in diabetic mice, it remains undetermined whether treatment with a TLR4 antagonist reduces atherosclerosis in nondiabetic or diabetic mice that have TLR4 expression. In this study, we determined the effect of Rhodobacter sphaeroides lipopolysaccharide (Rs-LPS), an established TLR4 antagonist, on early-stage atherosclerosis in nondiabetic and streptozotocin-induced diabetic apolipoprotein E-deficient (Apoe(-/-)) mice. Analysis of atherosclerotic lesions of both en face aortas and cross sections of aortic roots showed that administration of Rs-LPS in 14-week-old diabetic Apoe(-/-) mice for 10 weeks significantly reduced atherosclerotic lesions. Although atherosclerotic lesions in nondiabetic Apoe(-/-) mice appeared to be decreased by Rs-LPS treatment, the difference was not statistically significant. Metabolic study showed that Rs-LPS significantly lowered serum levels of cholesterol and triglycerides in nondiabetic mice but not in diabetic mice. Furthermore, immunohistochemistry studies showed that Rs-LPS inhibited the expression of interleukin 6 and matrix metalloproteinase-9 and reduced the content of monocytes and macrophages in atherosclerotic plaques. Taken together, this study demonstrated for the first time that TLR4 antagonist inhibited vascular inflammation and atherogenesis in diabetic Apoe(-/-) mice and lowered serum cholesterol and triglyceride levels in nondiabetic Apoe(-/-) mice.

Modulation of tumor necrosis factor related apoptosis-inducing ligand (TRAIL) receptors in a human osteoclast model in vitro

TRAIL (TNF-related apoptosis-inducing ligand) has been shown to induce apoptosis by binding to TRAIL-R1 and -R2 death receptors, but not to TRAIL-R3 or -R4, its decoy receptors that lack the internal death domain. Osteoclasts (Ocs) are sensitive to TRAIL-induced apoptosis, and modulation of these receptors may change Oc sensitivity to TRAIL. Using human Oc cultures, we first investigated the gene expression profile of these receptors (TNFRSF10 -A, -B, -C, -D encoding TRAIL-Rs 1-4) by real time PCR after adding osteotropic factors during the last week of Oc cultures. We observed a significant decrease in the expression of TNFRSF10-A after the addition of TGFβ, and an increase in that of TNFRSF10-A and -B post-PTH stimulation. Protein expression of TRAIL-R1 and -R3 was upregulated in the presence of MIP-1α, but down-regulated in the presence of TGFβ (R1), TRAIL (R2) or OPG (R3). The percentage of Ocs expressing the TRAIL-R1 and/or -R2 at their surface was increased by MIP-1α and TRAIL, increased (R2) or decreased (R1) by TGFβ, and the percentage expressing TRAIL-R3 was increased by MIP-1α, TRAIL and RANKL. Although significant, the magnitude of all these changes was of about 10-15%. While a direct correlation between these changes and TRAIL-induced Oc apoptosis was less clear, a protective effect was observed in Ocs that had been treated with OPG, and an additive effect in Ocs pre-treated with TRAIL or TGFβ increased TRAIL sensitivity.

Synthesis, cytotoxicity of new 4-arylidene curcumin analogues and their multi-functions in inhibition of both NF-κB and Akt signalling

A series of new 4-arylidene curcumin analogues (4-arylidene-1,7-bisarylhepta-1,6-diene-3,5-diones) were synthesized and found to be potent antiproliferative agents against a panel of cancer cell lines at submicromolar to low micromolar concentrations by SRB assay. Their inhibitory abilities against NF-κB was evaluated by High Content Analysis (HCA) based immunofluorescence assay; and the Akt signalling inhibition was determined by fluorescence polarization assay and western blot respectively. The Structure-Activity Relationship was discussed. Our results revealed that 4-arylidene curcumin analogues may work in a multi-targets manner in cancer cell.

Modulation of eIF5A expression using SNS01 nanoparticles inhibits NF-κB activity and tumor growth in murine models of multiple myeloma

Despite recent advances in the first-line treatment of multiple myeloma, almost all patients eventually experience relapse with drug-resistant disease. New therapeutic modalities are needed, and to this end, SNS01, a therapeutic nanoparticle, is being investigated for treatment of multiple myeloma. The antitumoral activity of SNS01 is based upon modulation of eukaryotic translation initiation factor 5A (eIF5A), a highly conserved protein that is involved in many cellular processes including proliferation, apoptosis, differentiation and inflammation. eIF5A is regulated by post-translational hypusine modification, and overexpression of hypusination-resistant mutants of eIF5A induces apoptosis in many types of cancer cells. SNS01 is a polyethylenimine (PEI)-based nanoparticle that contains both a B-cell-specific expression plasmid expressing a non-hypusinable mutant of eIF5A and a small interfering RNA (siRNA) which depletes endogenous hypusinated eIF5A. Reducing hypusine-modified eIF5A levels was found to inhibit phosphorylation and activity of ERK MAPK and nuclear factor-κB (NF-κB), and thus sensitize myeloma cells to apoptosis resulting from transfection of a plasmid expressing eIF5A(K50R). SNS01 exhibited significant antitumoral activity in both KAS-6/1 (95% inhibition; P < 0.05) and RPMI 8226 (59% inhibition; P < 0.05) multiple myeloma xenograft models following systemic administration. These results highlight the potential of using this approach as a new therapeutic strategy for multiple myeloma.

High frequency of inherited variants in the MEFV gene in patients with hematologic neoplasms: a genetic susceptibility?

Familial Mediterranean fever is an autosomal recessive disease occurring in populations originating from the Mediterranean basin. This autoinflammatory syndrome is caused by mutations in the Mediterranean FeVer (MEFV) gene. MEFV encodes a 781 amino acid protein known as pyrin. Pyrin is an important modulator of apoptosis, inflammation, and cytokine processing. In more recent pilot studies, inherited variant analysis of the MEFV gene in patients with hematologic neoplasm showed an unexpectedly high frequency of these variants in the gene. Here, we summarize the current state of knowledge of the relationship between inherited variants in the MEFV gene and hematologic neoplasms. Although no single underlying defect could be targeted in all hematologic neoplasms, it will be important to fully exploit the mechanisms underlying the neoplasm promoting role of inherited variants in MEFV. However, it is unclear how inherited variants in the MEFV gene are associated with tumor susceptibility or promotion in hematologic neoplasms. Further investigations are needed to determine the actual role of the MEFV gene in pathogenesis of these neoplasms.

Celastrol inhibits proliferation and induces chemosensitization through down-regulation of NF-κB and STAT3 regulated gene products in multiple myeloma cells

BACKGROUND AND PURPOSE

Activation of pro-inflammatory transcription factors NF-κB and signal transducer and activator of transcription 3 (STAT3) is one of the major contributors to both pathogenesis and chemoresistance in multiple myeloma (MM), which results in high mortality rate. Thus, in the present study, we investigated whether celastrol could suppress the proliferation and induce chemosensitization of MM cells by interfering with NF-κB and STAT3 activation pathways.

EXPERIMENTAL APPROACH

The effects of celastrol were investigated using both a virtual predictive tumour cell system and different MM cell lines resistant to doxorubicin, melphalan and bortezomib.

KEY RESULTS

Celastrol inhibited the proliferation of MM cell lines regardless of whether they were sensitive or resistant to bortezomib and other conventional chemotherapeutic drugs. It also synergistically enhanced the apoptotic effects of thalidomide and bortezomib. This correlated with the down-regulation of various proliferative and anti-apoptotic gene products including cyclin D1, Bcl-2, Bcl-xL, survivin, XIAP and Mcl-1. These effects of celastrol were mediated through suppression of constitutively active NF-κB induced by inhibition of IκBα kinase activation; and the phosphorylation of IκBα and of p65. Celastrol also inhibited both the constitutive and IL6-induced activation of STAT3, which induced apoptosis as indicated by an increase in the accumulation of cells in the sub-G1 phase, an increase in the expression of pro-apoptotic proteins and activation of caspase-3.

CONCLUSIONS AND IMPLICATIONS

Thus, based on our experimental findings, we conclude that celastrol may have great potential as a treatment for MM and other haematological malignancies.

Adenovirus as a new agent for multiple myeloma therapies: Opportunities and restrictions

Multiple myeloma is a malignancy of B-cells that is characterized by the clonal expansion and accumulation of malignant plasma cells in the bone marrow. This disease remains incurable, and a median survival of 3-5 years has been reported with the use of current treatments. Viral-based therapies offer promising alternatives or possible integration with current therapeutic regimens. Among several gene therapy vectors and oncolytic agents, adenovirus has emerged as a promising agent, and it is already being used for the treatment of solid tumors in humans. The main concern with the clinical use of this vector has been its high immunogenicity; adenovirus is often able to induce a strong immune response in the host. Furthermore, new limitations in the efficacy of this therapy, intrinsic to the nature of tumor cells, have been recently observed. For example, our group showed a strong antiviral phenotype in vitro and in vivo in a subset of tumors, shedding new insights that may explain the partial failure of clinical trials based on this promising new therapy. In this review, we describe novel therapeutic approaches that implement viral-based treatments in hematological malignancies and address the novelty as well as the possible limitations of these new therapies, especially in the context of the use of adenoviral vectors for treating multiple myeloma.

Resveratrol inhibits proliferation and survival of Epstein Barr virus-infected Burkitt's lymphoma cells depending on viral latency program

Resveratrol (3,4',5-trihydroxy-trans-stilbene), a polyphenolic natural product, shows chemopreventive properties against several cancers, heart diseases, inflammation, and viral infections. Epstein Barr virus (EBV), a γ-herpesvirus, contributes to the development of several human cancers including Burkitt's lymphoma (BL). In this study, we asked whether treatment with resveratrol would affect the viability of EBV-positive BL cells displaying different forms of latency. We report here that resveratrol, regardless of EBV status, induces caspase-dependent apoptosis by arresting cell-cycle progression in G(1) phase. However, resveratrol strongly induced apoptosis in EBV(-) and latency I EBV(+) cells, whereas latency II and latency III EBV(+) BL cells showed a survival advantage that increased with the extent of the pattern of viral gene expression. Resveratrol-induced cell-cycle arrest and apoptosis occurred in association with induction of p38 MAPK phosphorylation and suppression of ERK1/2 signaling pathway. Moreover, NF-κB DNA-binding activity was inhibited in all BL lines except EBV(+) latency III cells. LMP1 oncogene, which is expressed in latency III phenotype, is involved with the higher resistance to the antiproliferative effect of resveratrol because siRNA-mediated inhibition of LMP1 greatly increased the sensitivity of latency III BL cells as well as that of lymphoblastoid cell lines to the polyphenol. We propose that a combined resveratrol/siRNA strategy may be a novel approach for the treatment of EBV-associated B-cell malignancies in which the viral pattern of gene expression has been defined.

Inhibition of IGF-1 signalling enhances the apoptotic effect of AS602868, an IKK2 inhibitor, in multiple myeloma cell lines

Multiple myeloma (MM) is a B cell neoplasm characterized by bone marrow infiltration with malignant plasma cells. IGF-1 signalling has been explored as a therapeutic target in this disease. We analyzed the effect of the IKK2 inhibitor AS602868, in combination with a monoclonal antibody targeting IGF-1 receptor (anti-IGF-1R) in human MM cell lines. We found that anti-IGF-1R potentiated the apoptotic effect of AS602868 in LP1 and RPMI8226 MM cell lines which express high levels of IGF-1R. Anti-IGF-1R enhanced the inhibitory effect of AS602868 on NF-κB pathway signalling and potentiated the disruption of mitochondrial membrane potential caused by AS602868. These results support the role of IGF-1 signalling in MM and suggest that inhibition of this pathway could sensitize MM cells to NF-κB inhibitors.

NF-κB as a potential therapeutic target in myelodysplastic syndromes and acute myeloid leukemia

IMPORTANCE OF THE FIELD

The inactive NF-κB-inhibitor of NF-κB (IκB) complex is activated by stimuli including pro-inflammatory cytokines, mitogens, growth factors and stress-inducing agents. The release of NF-κB facilitates its translocation to the nucleus, where it promotes cell survival by initiating transcription of genes encoding stress-response enzymes, cell-adhesion molecules, pro-inflammatory cytokines and anti-apoptotic proteins. NF-κB and associated regulatory factors (IκB kinase subunits and bcl-3) are implicated in hematological and solid tumour malignancies. NF-κB appears to be involved in cell proliferation control, apoptosis control, angiogenesis promotion and possibly regulation of diffusion of metastases. There are several reports that inhibition of NF-κB as a therapeutic target may have a role in tumour cell death or growth inhibition.

AREA COVERED IN THIS REVIEW

We review data about inhibition of NF-κB in acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS). We describe the molecular mechanisms underlying NF-κB deregulation in these haematological malignancies.

WHAT THE READER WILL GAIN

Constitutive activation of NF-κB in the nucleus has been reported in some varieties of MDS/AML. The in vitro and in vivo results of NF-κB inhibition in myeloid malignancies are highlighted.

TAKE HOME MESSAGE

NF-κB selective inhibitory drugs may be useful, either as single agents or associated with conventional chemotherapy.