Nuclear NF-κB Expression Research Articles

Effect of metformin on TNF-α-induced migration of vascular smooth muscle cells and the underlying mechanism

Objective To explore the effect of metformin on TNF-α-induced migration of vascular smooth muscle cells(VSMCs)and the possible mechanism.Methods VSMCs were divided into four groups:control group,TNF-αgroup(10ng/mL),metformin group(2mmol/L)and metformin+TNF-αgroup(2mmol/L +10mg/mL).The migration of VSMCs was detected by wound healing assay and transwell assay.The expressions of matrix metalloproteinase(MMP)-2and MMP-9were detected by RT-PCR and Western blotting analysis;the protein expression of nuclear NF-κB and cytoplasmic IκB were also determined by Western blotting analysis.Results Wound healing assay and transwell assay showed that the migration ability of VSMCs in TNF-αgroup was significantly increased compared with the control group(P0.01),while that of metformin+TNF-αgroup was significantly decreased(P0.05).Compared with TNF-αgroup,the migration ability of metformin+ TNF-αgroup was significantly decreased(P0.01).MMP-2,MMP-9and NF-κB expression levels were significantly increased and the IκB expression was significantly decreased in TNF-αgroup compared with those in the control group(P0.01).Compared with TNF-αgroup,MMP-2,MMP-9and NF-κB expression levels were significantly decreased and IκB expression was significantly increased in metformin+ TNF-αgroup(P0.01).The intracellular expression levels of MMP-2and MMP-9were significantly different between metformin group and control group(P0.05 or P0.01),while the intracellular NF-κB,IκB proteins were not significantly different.Conclusion It suggests that metformin can effectively inhibit the TNF-α-induced migration of VSMCs,which might be related to the down-regulation of matrix metalloproteinases and the blockage of the NF-κB signal pathway.

FOXP3 inhibits NF-κB activity and hence COX2 expression in gastric cancer cells

Gastric cancer remains the main cause of cancer related deaths all over the world, and upregulated COX2 is a key player in its development. The mechanism as to how COX2 is regulated during the gastric cancer development is largely unknown. In this study, we found that the expression of COX2 was closely correlated with NF-κB activity. Strikingly, NF-κB activity was not absolutely consistent with its nuclear localization. Especially, in some cancer cell lines, such as MKN28, there were abundant nuclear localized NF-κB, while NF-κB luciferase activity in this cell line was relatively low. Furthermore, FOXP3 was found to be abundantly expressed in these cells. When the nuclear localized NF-κB expression was adjusted with the expression of FOXP3, it then correlated well with NF-κB activity. Molecularly, increased FOXP3 expression can interact with NF-κB and thus repress its activity. Knockdown of FOXP3 could increase NF-κB activity, COX2 expression, and cell migration. Taken together, our study revealed that function of FOXP3 as a negative regulator of NF-κB activity and thus plays a tumor suppressor role by reducing cell metastasis.

TM-233 Exerts Anti-Myeloma Activity and Overcomes Bortezomib-Resistance In Human Multiple Myeloma Cells By Targeting NF-κB and JAK/STAT Dual-Signaling Pathways

Although the introduction of bortezomib and immunomodulatory drugs (IMiDs) has led to improved outcomes in patients with multiple myeloma (MM), the disease remains incurable. Bortezomib, a proteasome inhibitor, is widely used in the treatment of MM and has resulted in marked therapeutic effects; however, this therapy is often complicated by peripheral neuropathy (PN), of which grade ≥3 PN is dose-limiting toxicity and can necessitate cessation of therapy. Subcutaneous administration of bortezomib can reduce the incidence of PN; however, among cases of PN that still occur, 24% are grade 2 PN and 6% are grade 3 PN. These data suggest that the incidence of PN higher than grade 2 is not attenuated by the subcutaneous delivery of bortezomib. In addition, patients often become refractory to bortezomib after long-term use. In an effort to identify potent and well-tolerated agents, clinical trials of novel agents (e.g., carfilzomib, pomalidomide, and monoclonal antibody against CS-1) are being conducted both in patients with newly diagnosed MM and in those with relapsed/refractory disease. We previously reported that 1’-acetoxychavicol acetate (ACA) obtained from the rhizomes of the plant Languas galanga induces cell death of MM cells in vitro and in vivo through inhibition of NF-κB-related functions (Cancer Res, 2005; 65: 4417). Subsequently, we developed several ACA analogs based on quantitative structure-activity relationship (QSAR) analysis to develop more potent NF-κB inhibitors, and successfully synthesized a novel benzhydrol-type analog of ACA, named TM-233, that exerted potent growth inhibition against various MM cells (U266, RPMI8226, and MM-1S cells) in a dose- and time-dependent manner when compared with ACA (Chem Pharm Bull., 2008; 56: 1490). Further, TM-233 inhibited constitutive phosphorylation of JAK2 and STAT3 and down-regulated the expression of anti-apoptotic Mcl-1 protein. TM-233 directly bound and activated the transcription of the Mcl-1 gene promoter. Mcl-1 is the downstream molecule of STAT3; therefore, these results suggest that TM-233 induces cell death in MM cells with down-regulated Mcl-1 via modulation of the JAK/STAT pathway. In addition, we examined the DNA-binding activity of NF-κB in TM-233-treated MM cells and found that NF-κB was inhibited by TM-233. Further, Western blotting showed that TM-233 rapidly decreased the nuclear expression of NF-κB but increased the accumulation of NF-κB in the cytosol, suggesting that TM-233 inhibits the translocation of NF-κB from the cytosol to the nucleus. Immunohistochemical analysis confirmed that the p50/RelA dimer of NF-κB was located in the cytosol and not in the nucleus in TM-233-treated MM cells. We then examined the effects of TM-233 on bortezomib-resistant MM cells. Bortezomib-resistant MM cell lines (i.e., KMS-11/BTZ and OPM-2/BTZ) were established by limiting dilution. We found that these cells have a unique point mutation, G322A, in the gene encoding the proteasome β5 subunit (Leukemia 2010; 24: 1506). TM-233, but not bortezomib, inhibited cellular growth and induced cell death in KMS-11/BTZ and OPM-2/BTZ cells in a time- (0-48 hours) and dose- (0-5 μM) dependent manner. Furthermore, the combination of low-dose TM-233 (less than 2 μM) and bortezomib (10 nM) significantly induced cell death in bortezomib-resistant MM cells via inhibition of NF-κB activity. These results indicate that TM-233 could overcome bortezomib resistance in MM cells by acting via different mechanisms from those of bortezomib. In conclusion, TM-233 induced cell death in MM cells, and this effect was mediated through the JAK/STAT and NF-κB dual-signaling pathways. These data indicate that TM-233 might be a more potent and more specific NF-κB inhibitor than that of original compound (ACA), and might be able to overcome bortezomib-resistance in MM cells. Therefore, further studies investigating clinical approaches, including combination therapy, are warranted. Disclosures: No relevant conflicts of interest to declare.

The NF-κB pathway is rarely spontaneously activated in mantle cell lymphoma (MCL) cell lines and patient’s samples

In this study, we investigated the role of NF-κB (canonical and alternative pathways) in the survival or proliferation of mantle cell lymphoma (MCL) cell lines. P50/p65 complexes were detectable by EMSA assays in 4/5 cell lines. Stable expression of a dominant-negative form of IkBa had no effect on proliferation nor on apoptosis in EBV-negative cell lines. Three out of 4 of the cell lines tested exhibited Phospho-p65 (Ser536). The alternative NF-κB pathway was not activated in 4/5 cell lines tested. Patient samples were also studied by Western blot, EMSA and Immunohistochemistry (IHC). No p50/p65 complexes were detected in cells freshly collected from 7 patients, but 1/7 cells exhibited Phospho-p65 (Ser536). We investigated immunohistochemically, the expression of NF-κB in 86 patients enrolled in two multicentre prospective trials. Patients with MCL exhibiting negative or positive cytoplasmic expression of NF-κB had a median overall survival of 35.7months compared to 22.4months for patients with nuclear NF-κB expression (p=0.0193). All these data suggest that NF-κB does not play a key role in proliferation and apoptotic processes in MCL cell lines. In patient samples, the presence of p65 in the nucleus reflecting NF-κB activation is rare but associated with a poor outcome.

MicroRNA‐146a targets PRKCE to modulate papillary thyroid tumor development

MicroRNAs are single-stranded noncoding RNAs composed of approximately 22 nucleotides that suppress gene expression by selectively binding via base-pairing to the complementary 3'-untranslated region (3'-UTR) of messenger RNA transcripts. Protein kinase C epsilon (PKCε) is an important modulating member of the transducing Ras/Raf-1 signal pathway; a computational search revealed miR-146a putatively binds to the 3'-UTR of the PRKCE gene, and thus decreasing PKCε expression. Moreover, PKCε inhibits mitochondrial apoptosis and is associated with the Bcl family. However, it has been previously reported that miR-146a expression in papillary thyroid carcinoma (PTC) is slightly elevated. Thus, we hypothesized that because miR-146a expression depends on nuclear factor kappaB (NF-κB) activation and NF-κB expression is elevated in PTC, miR-146a is potentially upregulated in PTC via negative feedback of NF-κB, and thus suppressing PKCε expression. In our study, we investigated whether overexpression of miR-146a, a tumor-suppressing-miR, in PTC cells decreases cell survival and induces apoptosis. Luciferase reporter assay analysis confirmed the direct binding of miR-146a and PRKCE 3'-UTR. Specific overexpression of exogenous miR-146a significantly decreased PKCε levels in PTC cell line NPA-187 and increased apoptosis. Additionally, using stably expressing miR-146a thyroid carcinoma cells to establish subcutaneous tumors, the tumor growth exhibited significant inhibition. Our study confirmed the tumor-suppressing role of miR-146a in thyroid carcinoma cells and contributes to the knowledge regarding modulation of Ras/Raf-1 signal transduction and apoptosis via PKCε targeted by miR-146a in PTC; moreover, our findings confirmed that miR-146a is involved in the feedback system of the classical NF-κB signal pathway in PTC.

Nuclear Expression of Glioma-Associated Oncogene Homolog 1 and Nuclear Factor-κB Is Associated with a Poor Prognosis of Pancreatic Cancer

Objective: We investigated the association of the hedgehog pathway with nuclear factor (NF)-κB and clinical outcomes in pancreatic cancer patients. Methods: We analyzed tissue samples for the expression of NF-κB (RelA/p65), sonic hedgehog (Shh) and glioma-associated oncogene homolog 1 (Gli1) by immunohistochemistry and investigated their expression in association with clinical outcomes. Results: Eighty-one patients with pancreatic cancer were investigated. Expression of Shh and nuclear expression of Gli1 and NF-κB were found in 63 of 66 (96%), 28 of 68 (41%) and 22 of 68 cases (32%), respectively. Nuclear Gli1 expression was closely associated with nuclear expression of NF-κB (p < 0.001). Patients with nuclear Gli1 had significantly worse prognoses than those without (median survival 7.9 vs. 13.9 months; p = 0.009). Similarly, patients with nuclear expression of NF-κB had shorter overall survival than those with negative or cytoplasmic expression of NF-κB (median survival 5.5 vs. 13.9 months; p < 0.001). Shh expression had no prognostic significance. In the multivariate analysis, NF-κB nuclear expression was closely associated with unfavorable overall survival (p = 0.02). Conclusion: Our results indicate that nuclear expression of Gli1 or NF-κB is a strong predictor of poor prognosis in pancreatic cancer. Additional investigation of the biologic significance of this association is warranted.

TRAF2 regulates the cytoplasmic/nuclear distribution of TRAF4 and its biological function in breast cancer cells

Although numerous studies have shown that tumor necrosis factor receptor-associated factor 4 (TRAF4) plays an important role in the carcinogenesis of many tumor types, its exact molecular mechanism remains elusive. In this study, we examined the regulation function of TRAF2 to the cytoplasmic/nuclear distribution of TRAF4 in the breast cancer cell line. Using cell immunofluorescent staining, we found that TRAF2 and TRAF4 were co-localized to the cytoplasm in MCF-7 cells. Co-immunoprecipitation showed that TRAF2 could interact with TRAF4 in MCF-10A, MCF-7 and MDA-MB-231 cell lines. Western blotting showed TRAF2 depletion by targeted siRNA in MDA-MB-231 cells led to reduced TRAF4 expression in the cytoplasm and augmented TRAF4 expression in the nucleus. Cytoplasmic expression of TRAF4 was augmented and nuclear expression was reduced when MCF-7 cells were transfected with hTRAF2pLPCX-HA-Flag/P874. MCF-7 cells expressing hTRAF2pLPCX-HA-Flag/P874 had enhanced cell proliferation rates. The nuclear expression of NF-κB significantly increased after TNF-α treatment. When hTRAF2pLPCX-HA-Flag/P874 and the siRNA-TRAF4 plasmid were cotransfected, the nuclear expression of NF-κB was significantly reduced compared with cells transfected with hTRAF2pLPCX-HA-Flag/P874 only. In conclusion, TRAF2 appears to interact with TRAF4 and affect the localization of TRAF4 in breast cancer cell lines. The overexpression of TRAF2 augmented the cytoplasmic expression of TRAF4 which promoted cell proliferation and inhibited cell apoptosis by activating NF-κB nuclear transcription. TRAF4 may play an important role in the activation of NF-κB via TRAF2.

Nuclear NF-κB Expression Correlates With Outcome Among Patients With Head and Neck Squamous Cell Carcinoma Treated With Primary Chemoradiation Therapy

To examine whether nuclear NF-κB expression correlates with outcome in patients with head and neck squamous cell carcinoma (HNSCC) treated with primary chemoradiation therapy (CRT). Between 2007 and 2010, 101 patients with locally advanced primary HNSCC were treated with definitive simultaneous CRT. Pretreatment biopsy specimens were analyzed for NF-κB p65 (RelA) nuclear immunoreactivity. A sample was assigned to be positive with more than 5% positive nuclear expression. The predictive relevance of NF-κB and clinicopathologic factors for overall survival (OS), progression-free survival (PFS), local progression-free survival (LPFS), and metastasis-free survival (DMFS) was examined by univariate and multivariate analysis. No significant differences between the groups were observed with regard to age, sex, total radiation dose, fractionation mode, total chemotherapy applied, T stage or grading. Patients with p65 nuclear positive biopsy specimens showed significantly a higher rate of lymph node metastasis (cN2c or cN3 status, P=.034). Within a mean follow-up time of 25 months (range, 2.33-62.96 months) OS, PFS, and DMFS were significantly poorer in the p65 nuclear positive group (P=.008, P=.027, and P=.008, respectively). These correlations remained significant in multivariate analysis. NF-κB/p65 nuclear expression is associated with increased lymphatic and hematogenous tumor dissemination and decreased survival in HNSCC patients treated with primary CRT. Our results may foster further investigation of a predictive relevance of NF-κB/p65 and its role as a suitable target for a molecular-based targeted therapy in HNSCC cancer.

Antitumoral effects of vasoactive intestinal peptide in human renal cell carcinoma xenografts in athymic nude mice

We studied antitumor effect of VIP in human renal cell carcinoma (RCC) (A498 cells xenografted in immunosuppressed mice). VIP-treated cells gave resulted in p53 upregulation and decreased nuclear β-catenin translocation and NFκB expression, MMP-2 and MMP-9 activities, VEGF levels and CD-34 expression. VIP led to a more differentiated tubular organization in tumours and less metastatic areas. Thus, VIP inhibits growth of A498-cell tumours acting on the major issues involved in RCC progression such as cell proliferation, microenvironment remodelling, tumour invasion, angiogenesis and metastatic ability. These antitumoral effects of VIP offer new therapeutical possibilities in RCC treatment.

Protective Role of (RS)-glucoraphanin Bioactivated with Myrosinase in an Experimental Model of Multiple Sclerosis

The discovery of new natural compounds with pharmacological properties is a field of interest widely growing. Recent literature shows that Brassica vegetables (Cruciferae) possess therapeutic effects particularly ascribed due to their content in glucosinolates, which upon myrosinase hydrolysis release the corresponding isothiocyanates. This study examines the potential neuroprotective and immunomodulatory effects of (RS )-glucoraphanin from Tuscan black kale (Brassica oleracea L. var. acephala sabellica) bioactivated with myrosinase (bioactive RS -GRA) (10 mg/kg/day intraperitoneally), in an experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis. EAE was induced by immunization with myelin oligodendroglial glycoprotein peptide (MOG35-55 ) in mice. After immunization, mice were observed daily for signs of EAE and weight loss. Clinical score was evaluated using a standardized scoring system. By Western blot analysis of spinal cord tissues, we have demonstrated that treatment with bioactive RS -GRA significantly decreased nuclear factor (NF)-kB translocation, pro-inflammatory cytokine production such as interleukin-1β (IL-1β), and apoptosis (Bax and caspase 3 expression). Our results clearly demonstrate that bioactive RS -GRA treatment may represent a useful therapeutic perspective in the treatment of this disease.

Role of cysteinyl leukotriene receptor-1 antagonists in treatment of experimentally induced mammary tumor: does montelukast modulate antitumor and immunosuppressant effects of doxorubicin?

It has been reported that a leukotriene (LT)-D4 receptor (i.e. cysteinyl LT1 receptor; CysLT1R) has an important role in carcinogenesis. The current study was carried out to assess the possible antitumor effects of montelukast (MON), a CysLT1R antagonist, in a mouse mammary carcinoma model, that is, a solid Ehrlich carcinoma (SEC). Effects of MON on tumor-induced immune dysfunction and the possibility that MON may modulate the antitumor and immunomodulatory effects of doxorubicin (DOX) were also studied. The effects in tumor-bearing hosts of several dosings with MON (10 mg/kg, per os), with and without the added presence of DOX (2 mg/kg, intraperitoneal), were investigated in vivo; end points evaluated included assessment of tumor volume, splenic lymphocyte profiles/functionality, tumor necrosis factor-α content, as well as apoptosis and expression of nuclear factor-κB (NF-κB) among the tumor cells. The data indicate that MON induced significant antitumor activity against the SEC. MON treatments also significantly mitigated both tumor- and DOX-induced declines in immune parameters assessed here. Moreover, MON led to decreased NF-κB nuclear expression and, in doing so, appeared to chemosensitize these tumor cells to DOX-induced apoptosis.

Protective effects of recombinant human bone morphogenetic protein-7 on focal cerebral ischemia–reperfusion injury

This study was to investigate the protective effect of recombinant human bone morphogenetic protein-7 (rhBMP-7) on focal cerebral ischemia–reperfusion (IR) injuries and their underlying mechanisms. An intraluminal suture method was used to generate a middle cerebral artery occlusion model in rats, which was followed by reperfusion. A sham operation (SO) group underwent the procedure without occlusion, whereas an IR group and rhBMP-7 treated group (RT) underwent occlusion in the absence and presence of rhBMP-7 (250 μg/kg) administered via a femoral vein injection 30 minutes prior to reperfusion. Twenty-four hours after reperfusion, neurological function, brain water content and morphological alterations were examined. Apoptosis was detected using terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assays, and immunohistochemical staining and Western blot assays were used to detect nuclear nuclear factor-kappa B (NF-κB) p65 expression. Compared with the SO group, IR rats showed a decrease in neurological function, an increase in brain water content, and pathological and morphological damage (p < 0.05). Higher levels of apoptosis were also detected in the infarct region area. In contrast, RT rats had reduced injury after IR. In addition, while immunohistochemical staining and western blot assays consistently detected increased expression of nuclear NF-κB after IR, these levels were reduced in the RT group. Administration of rhBMP-7 prior to reperfusion effectively inhibited the extent of IR injury by attenuating cerebral edema and ameliorating ultrastructural damage. The underlying mechanisms responsible for these observations potentially involve the inhibition of apoptosis induced by IR by rhBMP-7 via an NF-κB-related signaling cascade.

Enhancement of lipopolysaccharide-induced toll-like receptor 2 expression and inflammatory cytokine secretion in HUVECs under high glucose conditions

AimsEndothelial inflammatory responses mediated by toll-like receptors (TLRs) play an important role in atherogenesis. We aimed to investigate the exacerbation of an inflammatory response in human umbilical vein endothelial cells (HUVECs) under high glucose conditions. Main methodsHUVECs were exposed to normal glucose (5.5mmol/L) and high glucose (25, 50mmol/L), alone or with lipopolysaccharide (LPS 0, 10, 100, or 1000μg/L). Then concentrations of TNF-α and IL-6 in the culture supernatants were determined. The expression of toll-like receptor 2 (TLR2), TLR4 and NF-κB was evaluated by Western blot and RT-PCR analysis. Key findingsCompared with the normal glucose group, exposure of HUVECs to 50mmol/L of glucose or 1000μg/L of LPS significantly increased the concentrations of TNF-α and IL-6 in the culture supernatants. Neither 25mmol/L of glucose nor low concentration of LPS (≤100μg/L) alone had an effect on TNF-α and IL-6 release, or TLR2 expression, but they stimulated the inflammatory response and TLR2 expression under high glucose conditions (25mmol/L) in combination. LPS (100μg/L) did not alter the TLR4 expression in HUVECs under high glucose condition. Co-incubation with glucose and LPS increased the nuclear NF-κB expression in endothelial cells. Both NF-κB inhibitor and ROS scavenger could inhibit the enhancement of LPS-induced TLR2 expression and inflammatory cytokine secretion under high glucose conditions. SignificanceWe show in vitro data on the potential role of high glucose in increasing LPS-induced TLR2 expression and inflammatory cytokine secretion in HUVECs, offering a new insight into the pathophysiological pathways involved in atherosclerosis.

Expression of Molecular Markers in Tumours of Patients with Breast Cancer

The expression of transcription factor NF-κB (p50 and p65), ER, PR, Her2/neu, Ki-67, p53, Bcl-2 and E-cadherin in tumor tissue of 132 patients with breast cancer was investigated by immunohistochemistry. As a result of researches the correlation between Grade and expression of ER, PR, Bcl-2, Ki-67 and p65-subunit of NF-κB was defined. The level of proliferation was correlated with ER, PR, Bcl-2, p53 and Her2/neu expression. Also the correlation between some of investigated markers was found. Thus, high level of NF-κB nuclear expression was associated with Her2/neu hyperexpression and negative status of ER, PR and Bcl-2. These data may indicate poor prognosis and resistance to chemotherapy in breast cancer patients with activated NF-κB, but it requires further research and retrospective analysis of large number of patients.

TM-233, a Novel Analog of 1’-Acetoxychavicol Acetate (ACA), Induces Cell Death in Human Myeloma Cells by Inhibiting Both JAK/STAT and NF-κB Pathways: A Possible New Agent for Overcoming Bortezomib-Resistance.

Abstract 2939Multiple myeloma (MM) remains incurable despite the use of conventional and high-dose chemotherapy with stem cell transplantation. However, novel agents such as thalidomide, lenalidomide, and bortezomib have already achieved promising clinical results. In particular, bortezomib, a proteasome inhibitor, is widely used in the treatment of MM and has remarkable clinical effects in both refractory/relapsed and newly diagnosed patients. However, acquired drug resistance and serious toxicities such as peripheral neuropathy are often triggered by bortezomib in the clinical settings. Therefore, novel targeted agents with less toxicity are necessary to overcome bortezomib-resistance and improve clinical outcomes in MM. We have previously reported that 1’-acetoxychavicol acetate (ACA), a component of a traditional Asian condiment obtained from the rhizomes of the commonly used ethno-medicinal plant Languas galanga, has an inhibitory effect on NF-κB, and induces cell death in MM cells both in vitro and in vivo (Cancer Res, 2005; 65: 4417). With the aim of discovering more potent NF-κB inhibitors, we subsequently developed several ACA analogs based on quantitative structure-activity relationship (QSAR) analysis. This showed that a novel benzhydrol-type analog of ACA (TM-233) exhibited greater inhibition of NF-κB activity in MM cells when compared with ACA. In the present study, we examined the effects of TM-233 on various MM cells, including those resistant to bortezomib and we investigated the molecular mechanism of TM-233-induced cell death in these cells.TM-233 inhibited cell proliferation and induced cell death in various MM cell lines (U266, RPMI8226, and MM-1S cells) in a time (0–48 hours)- and dose (0–5 μM)- dependent manner. Similarly potent activity was observed against primary MM cells. Exposure of bone marrow mononuclear cells from 3 patients with MM to TM-233 revealed selective activity under the same conditions as for cell lines. Moreover, TM-233 did not inhibit colony formation in CD34-positive cells from human umbilical cord blood; therefore, TM-233 did not influence the normal blood cells. We next investigated the effects of TM-233 on the various signaling pathways including JAK/STAT and NF-κB in MM cells. TM-233 activated apoptosis-related caspase-3, -8, -9, and PARP, suggesting that cell death related to TM-233 is mediated by both mitochondrial- and Fas-dependent pathways. Furthermore, treatment with TM-233 inhibited constitutive activation of JAK2 and STAT3, and then downregulated the expression of anti-apoptotic Mcl-1 protein, but not that of Bcl-2 and Bcl-xL proteins. TM-233 directly bound and activated the transcription of the Mcl-1 gene promoter, suggesting that TM-233-induced cell death in MM cells down-regulated Mcl-1 via modulation of the JAK/STAT pathway. In addition, the DNA-binding activity of NF-κB in MM cells was inhibited by the treatment of TM-233. Further, TM-233 rapidly decreased the nuclear expression of NF-κB, but increased the accumulation of cytosol NF-κB, suggesting that TM-233 inhibits the translocation of NF-κB from the cytosol to the nucleus. These results indicate that TM-233 induced cell death in MM cells occurs via both JAK/STAT and NF-κB pathways. We finally examined the effects of TM-233 on bortezomib-resistant MM cells. We have recently established the bortezomib-resistant MM cell lines, KMS-11/BTZ and OPM-2/BTZ (Leukemia 2010; 24: 1506). We found that these cells have a unique point mutation, G322A, in the gene encoding the proteasome b5 subunit, resulting in bortezomib-resistance mediated through prevention of the accumulation of unfolded proteins and fatal ER stress. TM-233, but not bortezomib, inhibited cellular proliferation and induced cell death in KMS-11/BTZ and OPM-2/BTZ cells in a time- and dose-dependent manner. Interestingly, the combination of TM-233 and bortezomib significantly induced cell death in these bortezomib-resistant MM cells via inhibition of NF-κB activity. These results indicate that TM-233 could overcome bortezomib resistance in MM cells by acting according to a different mechanism from that of bortezomib, possibly inhibition of the JAK/STAT pathway.In conclusion, TM-233, a novel analog of ACA, might be a more potent NF-κB inhibitor than ACA and could overcome bortezomib-resistance in MM cells. Further studies investigating clinical applications are necessary and may yield interesting results. Disclosures:Iida:Janssen Pharmaceutical K.K.: Honoraria. Kizaki:Janssen Pharmaceutical K.K.: Honoraria.

Activation of NF-κB pathway in oral buccal mucosa during small intestinal ischemia-reperfusion injury

BackgroundIntestinal ischemia-reperfusion injury induces intestinal mucosal barrier disruption, systemic inflammatory response syndrome, multiorgan failure, and death. The major pathway for the systemic inflammatory responses depends on nuclear factor kappa B (NF-κB). However, direct measuring of NF-κB in injured tissues is not routinely available. Our aim was to determine whether NF-кB pathway in buccal mucosa is activated during intestinal ischemia-reperfusion injury. Materials and methodsMale Sprague-Dawley rats were prepared for the animal experiment. Superior mesenteric artery (SMA) was exposed and clamped for 30 min in the intestinal ischemia-reperfusion (IR) group. SMA was exposed only in control group. Serum, buccal mucosa, and small intestinal mucosa were harvested in 90 min after reperfusion in IR or 120 min after SMA exposure in control group. Serum cytokine levels and tissue NF-κB pathway activities were measured. ResultsSerum TNF-α (5.49 ± 2.72 versus 1.77 ± 1.20 pg/mL, P = 0.002) and interleukin-6 (232.32 ± 29.98 versus 115.92 ± 17.81 pg/mL, P = 0.002) levels were significantly higher in IR than control group. Intestinal mucosal cytoplasmic phosphorylated inhibitor kappa B (IκB)/IκB ratio, nuclear NF-κB expression, and NF-κB DNA-binding activity were significantly higher in IR than control group. Buccal mucosal cytoplasmic phosphorylated IκB/IκB ratio, nuclear NF-κB expression, and NF-κB DNA-binding activity were also higher in IR than control group. ConclusionBuccal mucosal NF-κB pathway was activated by intestinal ischemia-reperfusion injury. The present study suggests that buccal mucosal may be considered as an indicator for the assessment of intestinal ischemia-reperfusion injury.

Inflammatory cells of immunosuppressive phenotypes in oral lichen planus have a proinflammatory pattern of expression and are associated with clinical parameters

We sought to investigate the expression of cells with immunosuppressive/protumorigenic phenotypes in oral lichen planus (OLP), such as M2-tumor-associated macrophages (TAM2), myeloid-derived suppressive cells (MDSCs), and regulatory T cells (Tregs) in association with clinical parameters. Cases of hyperkeratotic (HK)-OLP (n = 23) and erosive (E)-OLP (n = 26) were immunohistochemically stained to determine the percentages of CD163-TAM2, CD80-MDSCs, and FOXP3-Tregs of proinflammatory CD121a-Th17, CD4 and CD8 lymphocytes, and of cells positive for nuclear factor kappa B (NF-κB) and transforming growth factor beta. Clinical parameters included symptoms, treatment approach, treatment response, and others. The inflammatory infiltrate in HK-OLP and E-OLP contained immunosuppressive cells; however, their pattern of expression was compatible with a proinflammatory response [membranous CD163-TAM2 staining (not extracellular), CD80+ lymphocytes (not macrophages), and a few Tregs]. The presence of CD4+, CD8+, and CD121a+ T lymphocytes was extensive. TAM2 were more frequent in E-OLP than in HK-OLP (P = 0.017). A higher frequency of CD80+ lymphocytes was associated with partial to no response to treatment (P = 0.028). Nuclear expression of NF-κB in the inflammatory cells was absent. The pattern of expression of the immunosuppressive cells, together with numerous CD4+, CD8+, and Th17-CD121a+ lymphocytes, suggest an extensive proinflammatory response rather than an immunosuppressive/protumorigenic response. The frequency of selective types of inflammatory cells calls for individual profile analyses of inflammatory infiltrates and individually adjusted treatment.

Role of cerebral endothelial cells in the astrocyte swelling and brain edema associated with acute hepatic encephalopathy

Brain edema is an important complication of acute hepatic encephalopathy (AHE), and astrocyte swelling is largely responsible for its development. Elevated blood and brain ammonia levels have been considered as major etiological factors in this edema. In addition to ammonia, recent studies have suggested that systemic infection, inflammation (and associated cytokines (CKs)), as well as endotoxin (lipopolysaccharide (LPS)) are also involved in AHE-associated brain edema. As endothelial cells (ECs) are the first resident brain cells exposed to blood-borne “noxious agents” (i.e., ammonia, CKs, LPS) that are present in AHE, these cells may be in a critical position to react to these agents and trigger a process resulting in astrocyte swelling/brain edema. We therefore examined the effect of conditioned media (CM) from ammonia, LPS and cytokine-treated cultured brain ECs on cell swelling in cultured astrocytes. CM from ammonia-treated ECs when added to astrocytes caused significant cell swelling, and such swelling was potentiated when astrocytes were exposed to CM from ECs treated with a combination of ammonia, LPS and CKs. We also found an additive effect when astrocytes were exposed to ammonia along with CM from ammonia-treated ECs. Additionally, ECs treated with ammonia showed a significant increase in the production of oxy-radicals, nitric oxide (NO), as well as evidence of oxidative/nitrative stress and activation of the transcription factor nuclear factor kappa B (NF-κB). CM derived from ECs treated with ammonia, along with antioxidants (AOs) or the NF-κB inhibitor BAY 11-7082, when added to astrocytes resulted in a significant reduction in cell swelling, as compared to the effect of CM from ECs-treated only with ammonia. We also identified increased nuclear NF-κB expression in rat brain cortical ECs in the thioacetamide (TAA) model of AHE. These studies suggest that ECs significantly contribute to the astrocyte swelling/brain edema in AHE, likely as a consequence of oxidative/nitrative stress and activation of NF-κB.

Abstract 110: Role of CARD 10 mediated NF-kB activation in colorectal carcinoma cells

Abstract Colorectal carcinoma is the fourth most common cancer in men and the third in women worldwide, accounting for 8% of all cancer deaths. NF-κB gene plays a role in tumorgenesis through the transcriptional activation of genes associated with cell proliferation, angiogenesis, metastasis, tumor promotion, inflammation and suppression of apoptosis. NF-κB protein activation, defined as nuclear expression of NF-κB by immunohistochemistry was an independent prognostic marker for poor survival. CARD10 gene is known positive regulator of the NF-κB activation pathway and can activate the NF-κB activity. CARD10 is an enzyme that is encoded by the CARD10 gene and it associates with IKK complex resulting in NF-κB activation. Considering the potential therapeutic utility of targeting NF-κB and its key modulators, we previously studied CARD10 genetic alterations and immunohistochemical expression of CARD10 in a large cohort cases1. CARD10 protein expression associated significantly with NF-κB activation, and CARD10 amplification was significantly associated with CARD10 protein expression and presence of distance metastasis. To extend and confirm our clinical finding, we performed in vitro studies using a panel of CRC cell lines to investigate the biological role of CARD10 alterations in CRC carcinogenesis. Our data showed that TNF-α treatment caused efficient translocation of p56 in CARD 10 muatation harboring cell line -DLD-1 cells to nucleus as compared to HCT-15 cells. Furthermore, the luciferase activity was significantly higher in CARD 10 amplified HCT-116 cells as compared to DLD1 and HCT-15 cells which carry normal CRAD10 gene copy number after 48 hours of transfection with an NF-κB reporter. In addition, it was also observed that the formation of colonies was significantly higher in HCT-116 as compared to DLD-1 and HCT-15. Finally CARD 10 siRNA transfection knocked down the expression of CARD10 and abrogated the expression of NF-κB, and resulted in apoptosis through activation of caspase-3. These data suggest that CARD10 mutation and amplification mediated NFκB activation play an important role in cellular transformation of CRC cells. Thus, the study raises the possibility that inhibition of CARD10 might have significant therapeutic value in CRC. Reference: 1: Jehad Abubaker, Prashant Bavi, Zeenath Jehan, Maqbool Ahmed, Wael Al-Haqawi, Mehar Sultana, Sarita Prabhakaran, Nasser Al-Sanea, Alaa Abduljabbar, Luai H Ashari, Samar Alhomoud, Fouad Al-Dayel, Shahab Uddin, Khawla S. Al-Kuraya. Clinicopathological significance of CARD10 alterations in Middle Eastern colorectal cancer. 102nd AACR Annual Meeting, April2-6, 2011, Orlando, Florida. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 110. doi:1538-7445.AM2012-110

Abstract 4498: Prognostic significance of nuclear factor kappa B expression in human papillomavirus-associated oropharyngeal cancer

Abstract Nuclear factor kappa B (NFκB) has been implicated in the development of head and neck squamous cell carcinoma (HNSCC) from premalignant changes to tumor progression and recurrence. However, the prognostic significance of cytoplasmic or nuclear localization of NFκB expression in human papillomavirus (HPV)-associated HNSCC has not been investigated largely due to limited patient samples. We hypothesized that cytoplasmic and/or nuclear expression of NFκB may be a poor prognostic factor for tumor recurrence and overall survival (OS) regardless of p16 status. We conducted a retrospective study with archival formalin-fixed paraffin-embedded tumor biopsies collected from 188 patients with oropharyngeal SCC between October 1994 and February 2008 from Emory University Department of Pathology. Median follow-up was 21.7 and 58.0 months for p16- and p16+ patients, correspondingly. Tumors were evaluated for p16 expression (a surrogate marker for HPV) by immunohistochemistry (IHC). Cytoplasmic expression of NFκBp65 by IHC or total expression combining cytoplasmic and nuclear localization were significantly greater in p16- patients (N=58) than p16+ patients (N=130), p&amp;lt;0.05. High cytoplasmic expression of NFκBp65 was significantly associated with poor OS (p=0.0276) and the total expression was associated with recurrence (p=0.0081) by log rank test, whereas nuclear NFκBp65 displayed weak association. Positive nuclear expression significantly correlated with smoking history (p=0.025). In conclusion, p16+ and low total NFκBp65 expression is associated with the best while p16- and high total NFκBp65 is associated with the worst OS in this patient cohort (Table I). (The study was supported by Head and Neck SPORE Grant P50CA128613). Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4498. doi:1538-7445.AM2012-4498