Intravenous injection of oligodeoxynucleotides to the NF-kappaB binding site inhibits hepatic metastasis of M5076 reticulosarcoma in mice

CTRP1 Knockout Attenuates Tumor Progression in A549 and HCT116 Cancer Cells

Simple Summary

CTRP1 belongs to the C1q and TNF-related protein family, and we generated CTRP1 knockout cells to examine the role of CTRP1 in tumor progression. CTRP1 knockout attenuates cell growth, invasion and tumor growth in mice, suggesting that CTRP1 expression promotes tumor progression.

Abstract

C1q and TNF-related 1 (C1QTNF1/CTRP1) is an adiponectin-associated protein belonging to the C1q/TNF-related protein family. Recent studies have shown that the C1q and TNF-related protein (CTRP) family is involved in cancer progression; however, the specific role of CTRP1 in tumor progression has not yet been elucidated. To examine the role of CTRP1 in tumor progression, we generated CTRP1 knockout A549 and HCT116 cell lines, which reduced the expression levels of nuclear factor (NF)-κB-dependent and metastasis-promoting transcripts. We demonstrated that CTRP1 knockout inhibited the cell proliferation and invasion and tumor growth. Finally, database analysis showed that CTRP1 expression was upregulated in metastatic cancers and elevated levels of CTRP1 were associated with poor prognosis. These results suggest that CTRP1 expression contributes to NF-κB signaling and promotes tumor progression.

Icariin enhances radiosensitivity of colorectal cancer cells by suppressing NF-κB activity

Radiation therapy is an integral part of the current therapeutic protocols in colorectal cancer. However, only a small proportion of the patients achieved complete pathological response because of the treatment-induced resistance to radiation. Previous studies have shown that radioresistance is associated with NF-κB activation and that suppression of NF-κB could potentiate the response of colorectal cancer cells to radiotherapy. Icariin, a natural flavonoid, has been shown to suppress NF-κB activity. The present study was carried out to investigate whether icariin could act as a radiosensitizer in colorectal cancer cells and murine model of the colorectal cancer. We also sought to understand the mechanisms underlying the icariin-mediated radiosensitization. Our results showed that icariin enhanced the radiation-mediated anti-proliferative effect both in vitro and in vivo. Further, icariin exerted the anti-proliferative and/or pro-apoptotic effect possibly, by: (1) inducing the cell arrest in G2/M phases of the cell cycle, or by (2) downregulating NF-κB and the anti-apoptotic gene products monitored by this transcription factor. Icariin could also potentiate the efficacy of radiotherapy in the murine model of colorectal cancer. Taken together, these results suggest that the use of icariin may provide with a new approach for sensitizing the radiotherapy in colorectal cancer.

Transcription factor decoy against stem cells master regulators, Nanog and Oct-4: a possible approach for differentiation therapy

Transcription factor decoys (TFDs) are exogenous oligonucleotides which can compete by cis-elements in promoters or enhancers for binding to TFs and downregulating gene expression in a specific manner. It is believed that tumor mass originates from cancer stem cells (CSCs) which the same with embryonic stem cells (ESCs) have the properties of both pluripotency and self-renewal (stemness). Many transcription factors such as Nanog, Oct-4, Sox2, Klf4, and Sall4 act as master regulators in the maintenance of stemness in both cell types. Differentiation therapy is based on this theory that by differentiation of CSCs, tumor mass can be eliminated with common cancer therapy methods. To our knowledge, the present study is the first report of a TFD approach against master regulator of stemness, Nanog, Oct-4, and Klf4, for downregulation purposes in P19 embryonic carcinoma stem cell. Different simple and complex decoys against Nanog, OCT-4, Sox2, and Klf4 were designed and used for this purpose. The results showed that the applied decoys especially Nanog-specific decoy decreased the expression of downstream genes.

Novel IkB kinase inhibitors for treatment of nuclear factor-kB-related diseases

INTRODUCTION

NF-kB is a key regulator of inflammation and immunity in cancer development. The IkB kinase (IKK) is a multisubunit complex containing catalytic subunits termed IKK-α, -β and -γ. It is well known that many pro-inflammatory stimuli require the IKK-β subunit for NF-kB activation.

AREAS COVERED

NF-kB affects the progression of inflammation-related diseases,such as myocardial ischemia, bronchial asthma, arthritis, cancer and other diseases. We review the characteristics and effects of these inhibitors on inflammatory and other diseases.

EXPERT OPINION

Various synthesized IKK inhibitors have been developed and they will be used clinically in the near future.

Transfection of NF-κB decoy oligodeoxynucleotide suppresses pulmonary metastasis by murine osteosarcoma

Nuclear factor-kappa B (NF-κB) has a pivotal role in the progression and distant metastasis of cancers, including malignant bone tumors. To inhibit NF-κB activation, a new molecular therapy using synthetic double-stranded oligodeoxynucleotide (ODN) as a 'decoy' cis element against NF-κB has been developed. To determine whether pulmonary metastasis of osteosarcoma is reduced by inhibiting the action of NF-κB, NF-κB decoy ODN was transfected into the nuclei of murine osteosarcoma cells with high pulmonary metastatic potential, the LM8 cell line, using a three-dimensional alginate spheroid culture model. An in vitro study demonstrated the successful transfection of LM8 cells cultured in alginate beads by 'naked' NF-κB decoy ODN and that the activation of NF-κB signaling was significantly suppressed. Tumor growth was not affected by transfection of NF-κB decoy ODN, however, the expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule 1 (ICAM-1) mRNA was markedly decreased. Furthermore, the transfection of 'naked' NF-κB decoy ODN effectively suppressed pulmonary metastasis in an in vivo alginate bead transplantation model. Our results suggest that NF-κB has a central and specific role in the regulation of tumor metastasis and could be a molecular target for development of anti-metastatic treatments for osteosarcoma.

Potential use of iontophoresis for transdermal delivery of NF-kappaB decoy oligonucleotides

Topical application of nuclear factor-kappaB (NF-kappaB) decoy appears to provide a novel therapeutic potency in the treatment of inflammation and atopic dermatitis. However, it is difficult to deliver NF-kappaB decoy oligonucleotides (ODN) into the skin by conventional methods based on passive diffusion because of its hydrophilicity and high molecular weight. In this study, we evaluated the in vitro transdermal delivery of fluorescein isothiocyanate (FITC)-NF-kappaB decoy ODN using a pulse depolarization (PDP) iontophoresis. In vitro iontophoretic experiments were performed on isolated C57BL/6 mice skin using a horizontal diffusion cell. The apparent flux values of FITC-NF-kappaB decoy ODN were enhanced with increasing the current density and NF-kappaB decoy ODN concentration by iontophoresis. Accumulation of FITC-NF-kappaB decoy ODN was observed at the epidermis and upper dermis by iontophoresis. In mouse model of skin inflammation, iontophoretic delivery of NF-kappaB decoy ODN significantly reduced the increase in ear thickness caused by phorbol ester as well as the protein and mRNA expression levels of tumor necrosis factor-alpha (TNF-alpha) in the mice ears. These results suggest that iontophoresis is a useful and promising enhancement technique for transdermal delivery of NF-kappaB decoy ODN.

NF-kappaB signalling: embracing complexity to achieve translation

NF-kappaB is a dimeric transcription factor that has emerged as an important regulator of liver homeostasis and is mechanistically implicated in a variety of liver pathologies including hepatitis, steatosis, fibrosis, and hepatocellular carcinoma. The question remains as to whether NF-kappaB can really be exploited for the development of therapeutics for these pathologies in the diseased human liver. This review casts a critical eye on the experimental evidence gathered to date and in particular questions the rationale for the current focus on components of the upstream IKK complex as therapeutic targets. We make the argument that translation of NF-kappaB biology to new therapies is more likely to emerge from a re-focus of basic research back to the NF-kappaB/Rel subunit functions and the complexities of their post-translational modifications and context-dependent co-regulator interactions.

Gene therapy targeting nuclear factor-kappaB: towards clinical application in inflammatory diseases and cancer

Nuclear factor (NF)-κB is regarded as one of the most important transcription factors and plays an essential role in the transcriptional activation of pro-inflammatory cytokines, cell proliferation and survival. NF-κB can be activated via two distinct NF-κB signal transduction pathways, the so-called canonical and non-canonical pathways, and has been demonstrated to play a key role in a wide range of inflammatory diseases and various types of cancer. Much effort has been put in strategies to inhibit NF-κB activation, for example by the development of pharmacological compounds that selectively inhibit NF-κB activity and therefore would be beneficial for immunotherapy of transplantation, autoimmune and allergic diseases, as well as an adjuvant approach in patients treated with chemotherapy for cancer. Gene therapy targeting NF-κB is a promising new strategy with the potential of long-term effects and has been explored in a wide variety of diseases, ranging from cancer to transplantation medicine and autoimmune diseases. In this review we discuss recent progress made in the development of NF-κB targeted gene therapy and the evolution towards clinical application.

Curcumin modulates the radiosensitivity of colorectal cancer cells by suppressing constitutive and inducible NF-kappaB activity

PURPOSE

Radiation therapy is an integral part of the preoperative treatment of rectal cancers. However, only a minority of patients achieve a complete pathologic response to therapy because of resistance of these tumors to radiation therapy. This resistance may be mediated by constitutively active pro-survival signaling pathways or by inducible/acquired mechanisms in response to radiation therapy. Simultaneous inhibition of these pathways can sensitize these tumors to radiation therapy.

METHODS AND MATERIALS

Human colorectal cancer cells were exposed to clinically relevant doses of gamma rays, and the mechanism of their radioresistance was investigated. We characterized the transcription factor nuclear factor-kappaB (NF-kappaB) activation as a mechanism of inducible radioresistance in colorectal cancer and used curcumin, the active ingredient in the yellow spice turmeric, to overcome this resistance.

RESULTS

Curcumin inhibited the proliferation and the post-irradiation clonogenic survival of multiple colorectal cancer cell lines. Radiation stimulated NF-kappaB activity in a dose- and time-dependent manner, whereas curcumin suppressed this radiation-induced NF-kappaB activation via inhibition of radiation-induced phosphorylation and degradation of inhibitor of kappaB alpha, inhibition of inhibitor of kappaB kinase activity, and inhibition of Akt phosphorylation. Curcumin also suppressed NF-kappaB-regulated gene products (Bcl-2, Bcl-x(L), inhibitor of apoptosis protein-2, cyclooxygenase-2, and cyclin D1).

CONCLUSIONS

Our results suggest that transient inducible NF-kappaB activation provides a prosurvival response to radiation that may account for development of radioresistance. Curcumin blocks this signaling pathway and potentiates the antitumor effects of radiation therapy.

Increase in nuclease resistance and incorporation of NF-kappaB decoy oligodeoxynucleotides by modification of the 3'-terminus

BACKGROUND

For the development of molecular therapy based on oligodeoxynucleotides (ODN), ODN have to be stable against nucleases and be specific to the target transcription factor. To decrease non-specific binding and degradation from the 3'-terminus of ODN, we designed partially annealed ODN by binding the extremities of two single strands, resulting in a ribbon-shaped ODN, so called ribbon-type decoy ODN (R-ODN).

METHODS

We evaluated the efficiency in the process of enzymatic ligation of R-ODN, the binding activity to nuclear factor-kappaB (NF-kappaB), and the stability against Exonuclease III and nucleases present in serum. The functional activity of R-ODN to inhibit NF-kappaB in vitro was evaluated in human aortic smooth muscle cells (VSMC): TNF-alpha-induced proliferation rate and MMP-9 expression were assessed after R-ODN transfection.

RESULTS AND CONCLUSIONS

Although R-ODN have a phosphodiester backbone, their physical conformation was designed to provide nuclease resistance without interfering with their binding activity. As expected, R-ODN showed more resistance to exonucleases and stability in 100% serum than non-modified decoy ODN (N-ODN). Importantly, the R-ODN construction did not interfere with its binding activity to NF-kappaB, similar to N-ODN. Transfection of R-ODN significantly inhibited the expression of MMP-9 induced by TNF-alpha in VSMC as assessed by real-time polymerase chain reaction (PCR), and R-ODN also inhibited the proliferation of VSMC induced by TNF-alpha (10 ng/ml), similar to phosphorothioate decoy ODN. Overall, the development of ribbon NF-kappaB decoy ODN could provide a useful tool for basic and clinical research.

Dual roles of NF-kappaB in cell survival and implications of NF-kappaB inhibitors in neuroprotective therapy

NF-kappaB is a well-characterized transcription factor with multiple physiological and pathological functions. NF-kappaB plays important roles in the development and maturation of lymphoids, regulation of immune and inflammatory response, and cell death and survival. The influence of NF-kappaB on cell survival could be protective or destructive, depending on types, developmental stages of cells, and pathological conditions. The complexity of NF-kappaB in cell death and survival derives from its multiple roles in regulating the expression of a broad array of genes involved in promoting cell death and survival. The activation of NF-kappaB has been found in many neurological disorders, but its actual roles in pathogenesis are still being debated. Many compounds with neuroprotective actions are strongly associated with the inhibition of NF-kappaB, leading to speculation that blocking the pathological activation of NF-kappaB could offer neuroprotective effects in certain neurodegenerative conditions. This paper reviews the recent developments in understanding the dual roles of NF-kappaB in cell death and survival and explores its possible usefulness in treating neurological diseases. This paper will summarize the genes regulated by NF-kappaB that are involved in cell death and survival to elucidate why NF-kappaB promotes cell survival in some conditions while facilitating cell death in other conditions. This paper will also focus on the effects of various NF-kappaB inhibitors on neuroprotection in certain pathological conditions to speculate if NF-kappaB is a potential target for neuroprotective therapy.

Gene therapy using ets-1 transcription factor decoy for peritoneal dissemination of gastric cancer

The ets-1 transcription factor plays an important role in cell proliferation, differentiation, apoptosis and tissue remodeling. Aberrant ets-1 expression correlates with aggressive tumor behavior and poorer prognosis in patients with various malignancies. This study evaluated the efficacy of double-stranded decoy oligonucleotides targeting ets-1-binding cis elements for the suppression of ets-1 in treatment of a peritoneal dissemination model of gastric cancer. In vitro, MTT assay was performed to evaluate the effect of the ets-1 decoy on cell growth. Electrophoretic mobility shift assay (EMSA) was performed to determine ets-1 activity. In vivo, the effect of the ets-1 decoy was investigated in the peritoneal dissemination nude mice model. Disseminated nodules were analyzed immunohistochemically. Ets-1 decoy, but not scrambled decoy, significantly inhibited cell growth in 2 gastric cancer cell lines, which showed overexpression of ets-1 protein by inhibiting the binding activity of ets-1. In the peritoneal dissemination model, the ets-1 decoy significantly suppressed the disseminated nodules, and tended to prolong the survival rate. PCNA index, microvessel density and VEGF expression were also reduced in peritoneal tumors treated with ets-1 decoy. Intraperitoneal injection of ets-1 decoy inhibited peritoneal dissemination of gastric cancer in a nude mice model. The results indicate that the decoy strategy for ets-1 offers a promising therapy for patients with incurable peritoneal dissemination of gastric cancer, most of which show overexpression of ets-1 protein.

Selective inactivation of NF-kappaB in the liver using NF-kappaB decoy suppresses CCl4-induced liver injury and fibrosis

Sustained hepatic inflammation induced by various causes can lead to liver fibrosis. Transcription factor NF-kappaB is important in regulating inflammatory responses, especially in macrophages. We presently investigated whether an NF-kappaB decoy, a synthetic oligodeoxynucleotide (ODN) imitating the NF-kappaB binding site, inhibited the inflammatory response after CCl(4) intoxication to prevent CCl(4)-induced hepatic injury and fibrosis. The NF-kappaB decoy was introduced into livers by injecting the spleens of mice, using a hemagglutinating virus of Japan (HVJ)-liposome method. ODN was transferred mainly to macrophages in normal or fibrotic livers. Increases in serum transaminases and production of inflammatory cytokines after a single challenge with CCl(4) were inhibited by the NF-kappaB decoy, which suppressed nuclear translocation of NF-kappaB in liver macrophages. Liver fibrosis induced by CCl(4) administration for 8 wk was suppressed by the NF-kappaB decoy, accompanied by diminished mRNA expression for transforming growth factor (TGF)-beta, procollagen type 1 alpha(1), and alpha-smooth muscle actin (SMA). In vitro, isolated liver macrophages showed increased DNA binding activity of NF-kappaB and inflammatory cytokine production after hydrogen peroxide treatment; both increases were inhibited significantly by the NF-kappaB decoy. In contrast, NF-kappaB decoy transferred to isolated hepatic stellate cells (HSC) had no effect on their morphological activation or alpha-SMA expression, although the decoy accelerated tumor necrosis factor (TNF)-alpha-induced apoptosis in activated HSC. The effect of NF-kappaB decoy suppressing fibrosis probably results mainly from anti-inflammatory effects on liver macrophages, with a possible minor contribution from its direct proapoptotic effect on activated HSC.

Balance of NF-kappaB and p38 MAPK is a determinant of radiosensitivity of the AML-2 and its doxorubicin-resistant cell lines

This study investigated radioresistance mechanisms in the doxorubicin-resistant acute myelogenous leukemia (AML)-2/DX100. AML-2/DX100 also showed resistance to radiation. AML-2/DX100 characterized by down-regulated catalase expression was supersensitive to exogenous hydrogen peroxide whereas they increased defense mechanisms against endogenous reactive oxygen species (ROS) as compared with AML-2/WT. In AML-2/WT, radiation increased Bax expression and its translocation to mitochondria but had little effect on translocation of Bcl-2 and consequently induced the release of cytochrome c from the mitochondria with the subsequent caspase-3 activation. On the contrary, in AML-2/DX100, radiation neither increased Bax expression nor its translocation to mitochondria while it increased Bcl-2 translocation to mitochondria. A specific p38 MAPK inhibitor SB203580 increased radioresistance in AML-2/WT but little in AML-2/DX100. It inhibited radiation-induced Bax translocation in AML-2/WT but not in AML-2/DX100, indicating that p38 MAPK is working after irradiation in AML-2/WT but not in AML-2/DX100. Electrophoretic mobility shift assay and Western blot analysis revealed that NF-kappaB in AML-2/DX100 was more activated with degradation of cytosolic IkappaBalpha than was that of AML-2/WT. cDNA microarray showed that Bfl-1/A1 and granzyme H in AML-2/DX100 were highly up-regulated (6.21-fold) and down-regulated (6.49-fold), respectively, as compared with each of AML-2/WT, which were confirmed by RT-PCR assay. Taken together, these results indicate that radioresistance mechanisms of AML-2/DX100 could be related to alterations in ROS-scavenging activity, in mitochondrial translocation of Bax and Bcl-2, and in expression of pro-apoptotic (granzyme H) and anti-apoptotic (Bfl-1/A1) genes. It has been shown that balance of p38 MAPK and NF-kappaB signals is a determinant in radiosensitivity of AML-2/WT and AML-2/DX100.

NF-kappaB as a potential molecular target for cancer therapy

Nuclear factor kappaB (NF-kappaB), a transcription factor, plays an important role in carcinogenesis as well as in the regulation of immune and inflammatory responses. NF-kappaB induces the expression of diverse target genes that promote cell proliferation, regulate apoptosis, facilitate angiogenesis and stimulate invasion and metastasis. Furthermore, many cancer cells show aberrant or constitutive NF-kappaB activation which mediates resistance to chemo- and radio-therapy. Therefore, the inhibition of NF-kappaB activation and its signaling pathway offers a potential cancer therapy strategy. In addition, recent studies have shown that NF-kappaB can also play a tumor suppressor role in certain settings. In this review, we focus on the role of NF-kappaB in carcinogenesis and the therapeutic potential of targeting NF-kappaB in cancer therapy.

Can NF-κB be a target for novel and efficient anti-cancer agents?

Since the discovery of the NF-kappaB transcription factor in 1986 and the cloning of the genes coding for NF-kappaB and IkappaB proteins, many studies demonstrated that this transcription factor can, in most cases, protect transformed cells from apoptosis and therefore participate in the onset or progression of many human cancers. Molecular studies demonstrated that ancient widely used drugs, known for their chemopreventive or therapeutic activities against human cancers, inhibit NF-kappaB, usually among other biological effects. It is therefore considered that the anti-cancer activities of NSAIDs (non-steroidal anti-inflammatory drugs) or glucocorticoids are probably partially related to the inhibition of NF-kappaB and new clinical trials are being initiated with old compounds such as sulfasalazine. In parallel, many companies have developed novel agents acting on the NF-kappaB pathway: some of these agents are supposed to be NF-kappaB specific (i.e. IKK inhibitors) while others have wide-range biological activities (i.e. proteasome inhibitors). Today, the most significant clinical data have been obtained with bortezomib, a proteasome inhibitor, for the treatment of multiple myeloma. This review discusses the preclinical and clinical data obtained with these various drugs and their putative future developments.

Construction of a novel DNA decoy that inhibits the oncogenic beta-catenin/T-cell factor pathway

The oncogenic beta-catenin/T-cell factor (TCF) signal is a common trigger inducing expressions of various cancer-related genes and is activated in various types of human malignancy. The aim of this study was to create an effective double-stranded DNA decoy that would interfere with endogenous TCF hyperactivity in tumor cells. We first established the TCF-activated model using nontumor human embryonic kidney 293 (HEK293) cells by introducing a beta-catenin cDNA. Based on a consensus TCF-binding sequence in the cyclin D1 and c-myc promoters, several double-stranded oligodeoxynucleotides were designed and tested for their ability to inhibit TCF activity in the HEK293 model. Among them, the 18-mer oligodeoxynucleotide stably formed double-stranded DNA and efficiently inhibited TCF activity. FITC-labeled oligodeoxynucleotide was efficiently incorporated into the nucleus at 6 hours and remained within cells for up to 72 to 96 hours. When compared with scrambled oligodeoxynucleotide, we found that the 18-mer TCF decoy significantly inhibited TCF activity and promoter activities of the downstream target genes, such as cyclin D1, c-myc, and matrix metalloproteinase 7 in HCT116 colon cancer cells. Reverse transcription-PCR assays indicated that mRNA expression of these genes decreased with treatment of the TCF decoy. Proliferation assay showed that the TCF decoy significantly inhibited growth of HCT116 tumor cells, but not of nontumor HEK293 cells. Our data provide evidence that the TCF decoy reduced both TCF activity and transcriptional activation of downstream target genes. Thus, this TCF decoy is potentially an efficient and nontoxic molecular targeting therapy for controlling malignant properties of cancer cells.

Tissue fibrosis and carcinogenesis: divergent or successive pathways dictate multiple molecular therapeutic targets for oligo decoy therapies

The extracellular matrix (ECM) is composed of several families of macromolecular components: fibrous proteins such as collagens, type I collagen (COL1), type III collagen (COL3), fibronectin, elastin, and glycoconjugates such as proteoglycans and matrix glycoproteins. Their receptors on the cell membrane, most of which in the case of the ECM belong to the integrins, which are heterodimeric proteins composed of alpha and beta chains. COL1 is the major fibrous collagen of bone, tendon, and skin; while COL3 is the more pliable collagen of organs like liver. Focus will not only be given to the regulation of synthesis of several fibrogenic parameters but also modulation of their degradation during growth factor-induced tissue fibrosis and cancer development. Evidence will be provided that certain tissues, which undergo fibrosis, also become cancerous. Why does there exist a divergency between tissues, which undergo frank fibrosis as an endpoint, and those tissues that undergo fibrosis and subsequently are susceptible to carcinogenicity; resulting from the etiological factor(s) causing the initial injury? For example, why does a polyvinyl alcohol (PVA) sponge implant become encapsulated and filled with fibrous tissue then fibrosis tissue growth stops? Why does the subcutaneous injection of a fibrogenic growth factor cause a benign growth and incisional wounding results in fibrosis and ultimately scarring? There are many examples of tissues, which undergo fibrosis as a prerequisite to carcinogenesis. Is there a cause-effect relationship? If you block tissue fibrosis in these precancerous tissues, would you block cancer formation? What are the molecular targets for blocking fibrosis and ultimately carcinogenesis? How can oligo decoys may be used to attenuate carcinogenesis and which oligo decoys specifically attenuate fibrogenesis as a prelude to carcinogenesis? What are other molecular targets for oligo decoy therapy in carcinogenesis?

STAT3 as a therapeutic target in head and neck cancer

The signal transducer and activator of transcription (STAT) proteins relay signals from cytokine receptors and receptor tyrosine kinases on the cell surface to the nucleus, where they affect the transcription of genes involved in normal cell functions, including growth, apoptosis and differentiation. STAT3 has been found to be constitutively active in head and neck squamous cell carcinoma (HNSCC) as well as in other epithelial malignancies. In HNSCC, STAT3 alters the cell cycle, prevents apoptosis, and mediates the proliferation and survival of tumour cells. Several therapeutic approaches are being developed to target STAT3, including molecules that block either dimerisation or DNA binding by STAT3, strategies to decrease STAT3 expression and drugs that inhibit STAT3 function. Strategies that block STAT3 may prove efficacious for cancer treatment.

Mediators involved in the cancer anorexia-cachexia syndrome: past, present, and future

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia, and anemia is invariably associated with the presence and growth of the tumor and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumor and the host leads to an accelerated starvation state, which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. Although the search for the cachectic factor(s) started a long time ago, and although many scientific and economic efforts have been devoted to its discovery, we are still a long way from knowing the whole truth. Present investigation is devoted to revealing the different signaling pathways, in particular transcriptional factors involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators (both humoral and tumoral) involved in cancer cachexia since they may represent targets for future promising clinical investigations.

Cytokines as mediators and targets for cancer cachexia

The cachexia syndrome, characterized by a marked weight loss, anorexia, asthenia and anaemia, is invariably associated with the growth of a tumour and leads to a malnutrition status caused by the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host results in a state of accelerated catabolism, which promotes severe metabolic disturbances in the patient. The search for the cachectic factor(s) started a long time ago, and many scientific and economic efforts have been devoted to its discovery, but we are still a long way from a complete answer. The present review aims to evaluate the different molecular mechanisms and catabolic mediators (both humoural and tumoural) that are involved in cancer cachexia and to discuss their potential as targets for future clinical investigations.

Inhibition of Sp1 activity by a decoy PNA-DNA chimera prevents urokinase receptor expression and migration of breast cancer cells

Sp1 regulates the activation of many genes involved in tumor growth, apoptosis, and angiogenesis. We have previously shown the involvement of Sp1 in the up-regulation of urokinase receptor (uPAR) expression, a key molecule in tumor invasion and metastasis. Here, we investigated whether a marked down-regulation of Sp1 activity may inhibit uPAR expression and migration ability of MDA-MB-231 breast cancer cells. To this end, we tested the decoy ability of a novel peptide nucleic acid (PNA)-DNA chimera which carries a central DNA strand, containing Sp1-binding sequence, covalently linked to two PNA fragments at both ends (PNA-DNA-PNA, PDP). The chimera was synthesized, annealed with complementary DNA (PDP-DNA), and then tested for its ability to bind Sp1 both in vitro and in living MDA-MB-231 breast cancer cells in the presence of urokinase (uPA). This PDP-DNA decoy molecule efficiently competes for the binding to endogenous Sp1 in nuclear extracts, and upon transfection with liposomal vectors, causes a marked decrease of available Sp1 in both untreated and uPA-treated MDA-MB-231 cells. Accordingly, both uPA-dependent enhancement of uPAR expression and cell migration were strongly reduced in transfected cells. Interestingly, a detectable inhibitory effect is also observed in breast cancer cells exposed to PDP-DNA in the absence of transfection reagents. Finally, the inhibitory effect of PDP-DNA appeared to be stronger than that observed with oligonucleotides carrying Sp1 consensus sequence. Our findings show that this novel PNA-DNA chimera, containing Sp1 consensus sequence, effectively inhibits Sp1 activity, uPAR expression, and motility of breast cancer cells indicating its potential therapeutic use to prevent tumor dissemination.

Somatic gene targeting with RNA/DNA chimeric oligonucleotides: an analysis with a sensitive reporter mouse system

BACKGROUND

Targeted gene correction provides a potentially powerful method for gene therapy. RNA/DNA chimeric oligonucleotides were reported to be able to correct a point mutation with a high efficiency in cultured rodent cells, in the body of mice and rats, and in plants. The efficiency of correction in the liver of rats was claimed to be as high as 20% after tail-vein injection. However, several laboratories have failed to reproduce the high efficiency.

METHODS

In order to sensitively detect and measure sequence changes by the chimeric oligonucleotides, we used Muta Mouse, a transgenic mouse system for mutation detection in vivo. It carries, on its chromosome, multiple copies of the lambda phage genome with the lacZ(+) gene. Two chimeric oligonucleotides were designed to make a point mutation at the active site of the LacZ gene product. They were injected into the liver with HVJ liposomes, which were demonstrated to allow reliable gene delivery. One week later, DNA was extracted from the liver, and lambda::lacZ particles were recovered by in vitro packaging. The lacZ-negative phage was detected by selection with phenyl-beta-D-galactoside.

RESULTS

The mutant frequency of the injected mice was at the same level as the control mouse (approximately 1/10000). Our further restriction analysis and sequencing did not detect the designed mutations.

CONCLUSIONS

Gene correction frequency in mouse liver by these oligonucleotides was shown to be less than 1/20000 in our assay with the Muta Mouse system.

Effects of nuclear factor-kappaB on rat hepatocyte regeneration and apoptosis after 70% portal branch ligation

AIM: To detect the DNA binding activity of nuclear factor-kappaB (NF-кB) in rat hepatocyte and to investigate the effects of NF-кB on rat hepatocyte regeneration and apoptosis after 70% portal branch ligation.

METHODS: Sixty Wistar rats were randomly divided into control group and portal branch ligation group. The animals were killed 12 h, 1, 2, 3, 7, and 14 d after surgery to determine the contents of plasma ALT. Hepatocytes were isolated and nuclear protein was extracted. DNA binding activity of NF-κB was measured by EMSA. Hepatocyte regeneration and apoptosis were observed under microscope by TUNEL staining. The ultrastructural changes of liver were observed under electron microscope.

RESULTS: Seventy percent portal branch ligation produced atrophy of the ligated lobes and the perfused lobes underwent compensatory regeneration, the total liver weight and plasma ALT levels were maintained at the level of sham-operated animals throughout the experiment. After 2 d of portal branch ligation, DNA binding activity of NF-кB in hepatocyte increased and reached its peak, the number of apoptotic hepatocyte in the ligated lobes and the number of mitotic hepatocyte in the perfused lobes also reached their peak. Typical apoptotic changes and evident fibrotic changes in the ligated lobes were observed under electron microscope.

CONCLUSION: After 70% portal branch ligation, DNA binding activity of NF-кB in hepatocyte is significantly increased and NF-кB plays an important role in hepatocyte regeneration and apoptosis.

The radical scavenger edaravone enhances the anti-tumor effects of CPT-11 in murine colon cancer by increasing apoptosis via inhibition of NF-κB

The transcription factor NF-kappaB is reportedly activated by anti-cancer chemotherapeutic compounds in many cancer cell lines and NF-kappaB activation is one mechanism by which tumors become resistant to apoptosis. Antioxidants have been reported to serve as potent NF-kB inhibitors. In this study, we investigated the ability of edaravone to enhance apoptosis induced by CPT-11 through inhibition of NF-kB. In vitro, SN38, the active metabolite of CPT-11, induced activation of NF-kB, the production of intracellular reactive oxygen species, the activation of caspase-3, and apoptosis in colon26 cells. Pretreatment with edaravone scavenged the SN38-produced reactive oxygen species, and inhibited the SN38-induced activation of NF-kB. Moreover, edaravone enhanced the activation of caspase-3, and the level of apoptosis induced by SN38. In vivo, the combination of edaravone with CPT-11 reduced subcutaneous tumor growth and number of pulmonary metastases more effectively than CPT-11 alone. These results demonstrate that the combination of edaravone with CPT-11 may constitute a new strategy for treating primary and metastatic colon cancer.

The pivotal role of cytokines in muscle wasting during cancer

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia and anemia, is invariably associated with the presence and growth of the tumour and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host leads to an accelerated catabolic state, which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. Although the search for the cachectic factor(s) started a long time ago, and although many scientific and economic efforts have been devoted to its discovery, we are still a long way from knowing the whole truth. Present investigation is devoted to unrevealing the different signaling pathways (particulary transcriptional factors) involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators involved in cancer cachexia since they may represent targets for future promising clinical investigations.

The pivotal role of cytokines in muscle wasting during cancer

The cachectic syndrome, characterized by a marked weight loss, anorexia, asthenia and anemia, is invariably associated with the presence and growth of the tumour and leads to a malnutrition status due to the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host leads to an accelerated catabolic state, which promotes severe metabolic disturbances in the host, including hypermetabolism, which leads to an increased energetic inefficiency. Although the search for the cachectic factor(s) started a long time ago, and although many scientific and economic efforts have been devoted to its discovery, we are still a long way from knowing the whole truth. Present investigation is devoted to unrevealing the different signaling pathways (particularly transcriptional factors) involved in muscle wasting. The main aim of the present review is to summarize and evaluate the different molecular mechanisms and catabolic mediators involved in cancer cachexia since they may represent targets for future promising clinical investigations.

In vivo transfection of a cis element 'decoy' against signal transducers and activators of the transcription 6 (STAT6) binding site ameliorates the response of contact hypersensitivity

We herein demonstrate that STAT6 plays an important role in the induction of not only acute contact hypersensitivity (CHS), but also chronic CHS in a mouse model using STAT6-deficient (STAT6(-/-)) mice. We, therefore, determine whether synthetic double-stranded DNA with a high affinity for STAT6 can be introduced in vivo as a decoy cis element to bind the transcriptional factor and block the induction of not only acute CHS but also chronic CHS. Treatment by the transfection of STAT6 decoy oligodeoxynucleotides (ODN), after the induction of 2,4,6-trinitrochlorobenzene or other haptens had a significant inhibitory effect on the induction of both acute CHS and chronic CHS. We thus examined the mechanism of the in vivo effect of the transfection of STAT6 decoy ODN in both acute and chronic CHS. In the histological analysis, the infiltration of eosinophils and degranulated mast cells, and the production of IL-4, IL-6 and eotaxin, but not IFN-gamma in the extracts from challenged skin significantly decreased by the transfection of STAT6 decoy ODN. We herein report the first successful in vivo transfer of STAT6 decoy ODN to inhibit acute and chronic CHS, thus providing a new therapeutic strategy not only for the treatment of CHS but also for atopic dermatitis.

Interleukin-10 plasmid DNA inhibits subcutaneous tumor growth of Colon26 adenocarcinoma in mice

The transcription factor NF-kappa B is constitutively activated in many human cancers, and induces the expression of multiple proteins including antiapoptotic proteins. Recent papers indicate that NF-kappa B activation is inhibited by interleukin (IL)-10. In this study, we investigated the effect of IL-10 plasmid DNA on colon cancer in mice. In vitro study: Colon 26 murine colon adenocarcinoma cells were either treated or untreated with IL-10 for 60 min. The cells were subsequently stimulated with TNF-alpha. In vivo study: to induce a high level of IL-10 in plasma, we transferred the naked plasmid vectors encoding the mouse IL-10 gene into the liver via the intravenous route. To establish tumors, we injected Colon 26 cells into BALB/c mice subcutaneously. In vitro study: a 24-h incubation with TNF-alpha did not affect cell viabilities; however, pretreatment with IL-10 significantly enhanced the level of apoptosis induced by TNF-alpha. Pretreating Colon 26 cells with IL-10 significantly attenuated the TNF-alpha-induced NF-kappa B activation. In vivo study: IL-10 plasmid controlled the growth of subcutaneous tumors. In subcutaneous tumor, NF-kappa B was activated in response to tumor growth. IL-10 plasmid markedly inhibited this activation of NF-kappa B in subcutaneous tumor. IL-10 plasmid induced cancer cell apoptosis linked to the down-regulation of antiapoptotic proteins, and the activation of caspase-3. These results demonstrate that IL-10 plasmid may constitute a new strategy for treating cancer growth.

In vivo transfection of NF-kappaB decoy oligodeoxynucleotides attenuate renal ischemia/reperfusion injury in rats

BACKGROUND

Ischemic acute renal failure (ARF) is a common and often fatal condition characterized by tubular epithelial cell necrosis and marked monocyte infiltration. Inflammatory mechanisms, including cell adhesion, cell infiltration, and cytokine production, are involved. These processes are thought to be directly or indirectly regulated by nuclear factor kappaB (NF-kappaB). Targeted of NF-kappaB might ameliorate ischemia/reperfusion (I/R) injury by inhibiting the production of genes that involved in ischemic ARF. The objective of the present study was to evaluate the effect of NF-kappaB decoy oligodeoxynucleotides (ODN) in experimental rat ischemic ARF.

METHODS

Ischemic ARF was induced by left renal artery clamping for 60 minutes, while the right kidney was being removed in female Sprague-Dawley rats. The effect of cationic liposome-protamine-NF-kappaB decoy ODN was evaluated after infusion into the kidney via the renal artery before clamping. After 24 hours of reperfusion, we then assessed morphologic and functional parameters, NF-kappaB/DNA binding activity, monocyte/macrophage (M/MPhi) infiltration, and gene expression in I/R kidney.

RESULTS

After 24 hours of reperfusion, compared with sham-operated animals, serum creatinine and blood urea nitrogen (BUN) levels in ischemic ARF animals were increased about 10-fold and fivefold respectively. (255.67 +/- 34.48 micromol/L vs. 25.33 +/- 2.23 micromol/L and 43.47 +/- 5.50 mmol/L vs. 8.45 +/- 0.43 mmol/L, P < 0.001), NF-kappaB/DNA binding activity was markedly elevated [median value was 1.75 vs. 0.15 relative density unit (RDU), P < 0.005]. NF-kappaB decoy ODN treatment reduced the elevation of serum creatinine level by 70% (79.17 +/- 8.64 micromol/L vs. 255.67 +/- 34.48 micromol/L, P < 0.01), BUN level by 40% (28.33 +/- 4.86 mmol/L vs. 43.47 +/- 5.50 mmol/L, P= NS), and almost abolished the NF-kappaB activation compared with levels observed in sham-operated rats (median value was 0.25 vs. 1.9 RDU, P < 0.005). Furthermore, NF-kappaB decoy ODN pretreatment prevented the occurrence of tubular necrosis and reduced the renal tubular damage scores markedly (1.85 +/- 0.06 vs. 3.63 +/- 0.06 scores, P < 0.01). In addition, M/MPhi infiltration was obviously suppressed (9.77 +/- 1.19 cells/hpf vs. 29.22 +/- 1.94 cells/hpf, P < 0.01), Moreover, results of reverse transcription-polymerase chain reaction (RT-PCR) and immunohistochemistry showed the up-regulation of monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) was greatly decreased, inducible nitric oxide synthase (iNOS) and endothelin-1 (ET-1) expression were also reduced, approaching levels observed in sham-operated animals. The data suggest that NF-kappaB decoy ODN treatment protects renal tissue from the effects of I/R injury and thus reduces the severity of ARF.

CONCLUSION

These experiments demonstrated that NF-kappaB plays a critical role in renal I/R injury by reducing a series of inflammatory genes. NF-kappaB decoy ODN treatment reduces the renal dysfunction and damage associated with ischemic ARF. Therefore, in vivo transfection of NF-kappaB decoy ODN provides a new therapeutic strategy for ischemic ARF.

Molecular therapy to inhibit NFkappaB activation by transcription factor decoy oligonucleotides

Molecular therapy is emerging as a potential strategy for the treatment of various diseases for which few known effective therapies exist. One strategy for combating disease processes has been to target the transcriptional process. Two approaches have been used to accomplish this: the use of antisense complimentary to the mRNA of interest and the use of ribozymes, a unique class of RNA molecules that not only store information but also process catalytic activity. Ribozymes are known to catalytically cleave specific target RNA, leading to its degradation, whereas antisense molecules inhibit translation by binding to mRNA sequences on a stoichiometric basis. More recently, small interfering RNA has been shown to inhibit target gene expression. The application of oligonuclotide technology, such as antisense, to regulate the transcription of disease-related genes in vivo has important therapeutic potential. Transfection of cis-element double-stranded oligodeoxynucleotides has been reported as a powerful tool in a new class of anti-gene strategies for molecular therapy.

Catabolic mediators as targets for cancer cachexia

The cachexia syndrome, characterized by a marked weight loss, anorexia, asthenia and anaemia, is invariably associated with the growth of a tumour and leads to a malnutrition status caused by the induction of anorexia or decreased food intake. In addition, the competition for nutrients between the tumour and the host results in an accelerated catabolism state, which promotes severe metabolic disturbances in the patient. The search for the cachectic factor(s) started a long time ago, and many scientific and economic efforts have been devoted to its discovery, but we are still a long way from a complete answer. The present review aims to evaluate the different molecular mechanisms and catabolic mediators (both humoural and tumoural) that are involved in cancer cachexia and to discuss their potential as targets for future clinical investigations.

NF-kappaB activation in cancer: a challenge for ubiquitination- and proteasome-based therapeutic approach

Nuclear factor-kappa B (NF-kappaB) activation relies primarily on ubiquitin-mediated degradation of its inhibitor IkappaB. NF-kappaB plays an important role in many aspects of tumor development, progression, and therapy. Some types of cancer are characterized by constitutive NF-kappaB activity, whereas in others such activity is induced following chemotherapy. NF-kappaB-harboring tumors are generally resistant to chemotherapy and their eradication requires NF-kappaB inhibition. Here we describe the mechanisms of NF-kappaB activation in normal and tumor cells, review prevalent notions regarding the factor's contribution to tumorigenicity and discuss present and future options for NF-kappaB inhibition in cancer. The ubiquitination-mediated activation of NF-kappaB is intersected by another cancer-associated protein, beta-catenin. We, therefore, compare the related activation pathways and discuss the possibility of differential targeting of the involved ubiquitination machinery.

Targeted gene therapy for rat glomerulonephritis using HVJ-immunoliposomes

BACKGROUND

Kidney targeted gene transfer has been attempted by many researchers over the last 10 years; however, unfortunately, no reliable technique for gene transfer to the kidney has been established. At experimental level several in vivo gene transfer methods have been reported.

METHODS

We were the first to report successful in vivo gene transfer into the kidney using the HVJ-liposome method. Since then, this method has been modified to achieve highly efficient gene transfer. In this study, we have developed a renal glomerulus-specific gene transfer method using HVJ-liposomes with anti-Thy 1 antibody, OX-7.

RESULTS

Following systemic delivery of fluoroisothiocyanate (FITC)-labeled oligodeoxynucleotides (ODN) by HVJ-liposomes coupled with OX-7, we observed fluorescence in renal glomeruli from 2 h post-administration. To examine the efficacy of this delivery system, NF-kappaB or scrambled (SD) decoy ODN was administered by HVJ-liposomes coupled with OX-7 into a crescent glomerulonephritis, anti-glomerular basement membrane (GBM) model. Animals given SD decoy ODN developed severe glomerulonephritis by day 7 with heavy albuminuria, glomerular crescent formation and up-regulated renal expression of IL-1beta and ICAM-1. In contrast, NF-kappaB decoy ODN treatment substantially inhibited the disease with a reduction in alubuminuria, histological damage and the renal expression of inflammatory cytokines.

CONCLUSIONS

This study has demonstrated that systemic delivery of HVJ-liposomes coupled with OX-7 results in efficient ODN transfer in rat glomeruli. NF-kappaB, but not SD decoy ODN administered systemically via HVJ-liposomes complexed with OX-7 showed clear therapeutic potential for glomerulonephritis. This novel ODN transfer method combined with decoy strategy has the potential to lead to the establishment of a new therapeutic approach to glomerular diseases.

Prevention and regression of atopic dermatitis by ointment containing NF-kB decoy oligodeoxynucleotides in NC/Nga atopic mouse model

Atopic dermatitis, a chronic inflammatory skin disease characterized by relapsing eczema and intense prurigo, requires effective and safe pharmacological therapy. In this study, we examined the efficacy of ointment containing NF-kB decoy oligodeoxynucleotides (ODN) on atopic dermatitis lesions in NC/Nga mice, which are characterized by the spontaneous onset of atopic dermatitis in conventional conditions. Topical administration of NF-kB decoy ODN twice a month resulted in a significant reduction in clinical skin condition score and marked improvement of histological findings. Reduction of the atopic skin condition by NF-kB decoy ODN was accompanied by a significant decrease in migration of mast cells into the dermis and an increase in apoptotic cells. Here, we demonstrated the successful treatment of atopic dermatitis with ointment containing NF-kB decoy ODN in a mouse model, promising new therapy for atopic dermatitis.

Effects of NFkappaB decoy oligonucleotides released from biodegradable polymer microparticles on a glioblastoma cell line

The objectives of this study were to investigate a nuclear factor-kappa B (NFkappaB) decoy oligonucleotide (ODN) strategy on the inhibition of glioblastoma (GBM) cell line growth and to evaluate a poly(DL-lactic-co-glycolic acid) (PLGA) microparticle delivery system for the NFKB decoy ODNs in vitro. We have demonstrated that NFkappaB activation is important in regulating GBM cell line growth. Aberrant nuclear expression of NFkappaB was found in a panel of GBM cell lines, while untransformed glial cells did not display NFkappaB activity. Nuclear translocation of NFkappaB was inhibited by using a 'decoy" ODN strategy. NFkappaB decoy ODNs designed to inhibit NFkappaB resulted in a significant reduction in cell number (up to 45%) compared to control cultures after 2 days. The reduction in cell number correlated with a decrease in cyclin D1 protein expression and a commensurate decrease in Cdk-4 activity. These results provide evidence suggesting that NFkappaB mediates cell cycle progression and demonstrates a mechanism linking increased NFkappaB activity with GBM cell growth and cell cycle disregulation. Decoy ODNs were encapsulated at a yield of 66% in PLGA microparticles and released in a controlled manner in phosphate buffered saline for up to 28 days. Approximately 83% of entrapped ODNs were released by day 28. During 3 days of GBM cell line culture, the released decoy ODNs retained their biologic activity and led to significantly reduced cell number as compared to control cultures. These findings offer a potential therapeutic strategy in the control of human GBM cell line growth in vitro and suggest that PLGA microparticles may be appropriate as delivery vehicles for the "decoy" ODN strategy.