Downregulation of TNF-alpha and VEGF expression by Sp1 decoy oligodeoxynucleotides in mouse melanoma tumor

Aberrant Water Structure Dynamics in B16 Melanoma-Bearing Mice by Time Domain Refractometry Analysis

Living bodies comprise approximately 55-75% water to maintain homeostasis. However, little is known about the comprehensive differences in in vivo water molecule dynamics (water structure dynamics; WSD) between physiological and pathophysiological statuses. Here, we examined the WSD of ex vivo tumor tissues and organs from tumor-bearing mice with engrafted mouse malignant melanoma cells (B16-F10) in the right flanks to compare with those in healthy mice, using time domain reflectometry of dielectric spectroscopy at days 9, 11, and 14 after engrafting. The relaxation parameters of relaxation time (τ), relaxation time distribution parameter (β), and relaxation strength (∆ε) were measured on tumor tissues and lung, liver, kidney, and skin tissues. Immediately afterward, the water contents (%) in the tumor and the other organs were calculated by measuring their weights before and after freeze-drying. Each parameter of the tumor was compared to that of pooled values of other organs in tumor-bearing (TO) and healthy mice (HO). The tumor water content temporarily increased compared to that of HO at day 11; the tumor volume was also prone to increase. In contrast, tumor tissues exhibited significantly higher values of β close to 1 of ultrapure water and ∆ε compared to TO and HO at all times. Moreover, β in the viscera of TO was prone to increase compared to that of HO with significantly higher levels at day 11. Conclusively, tumor-bearing mice exhibited systemically aberrant WSD, unlike healthy mice. Thus, dielectric spectroscopy in terms of WSD may provide novel pathophysiological perspectives in tumor-bearing living bodies.

Localized immune surveillance of primary melanoma in the skin deciphered through executable modeling

While skin is a site of active immune surveillance, primary melanomas often escape detection. Here, we have developed an in silico model to determine the local cross-talk between melanomas and Langerhans cells (LCs), the primary antigen-presenting cells at the site of melanoma development. The model predicts that melanomas fail to activate LC migration to lymph nodes until tumors reach a critical size, which is determined by a positive TNF-α feedback loop within melanomas, in line with our observations of murine tumors. In silico drug screening, supported by subsequent experimental testing, shows that treatment of primary tumors with MAPK pathway inhibitors may further prevent LC migration. In addition, our in silico model predicts treatment combinations that bypass LC dysfunction. In conclusion, our combined approach of in silico and in vivo studies suggests a molecular mechanism that explains how early melanomas develop under the radar of immune surveillance by LC.

DNA methylome and transcriptome alterations and cancer prevention by curcumin in colitis-accelerated colon cancer in mice

Inflammation is highly associated with colon carcinogenesis. Epigenetic mechanisms could play an important role in the initiation and progression of colon cancer. Curcumin, a dietary phytochemical, shows promising effects in suppressing colitis-associated colon cancer in azoxymethane-dextran sulfate sodium (AOM-DSS) mice. However, the potential epigenetic mechanisms of curcumin in colon cancer remain unknown. In this study, the anticancer effect of curcumin in suppressing colon cancer in an 18-week AOM-DSS colon cancer mouse model was confirmed. We identified lists of differentially expressed and differentially methylated genes in pairwise comparisons and several pathways involved in the potential anticancer effect of curcumin. These pathways include LPS/IL-1-mediated inhibition of RXR function, Nrf2-mediated oxidative stress response, production of NO and ROS in macrophages and IL-6 signaling. Among these genes, Tnf stood out with decreased DNA CpG methylation of Tnf in the AOM-DSS group and reversal of the AOM-DSS induced Tnf demethylation by curcumin. These observations in Tnf methylation correlated with increased and decreased Tnf expression in RNA-seq. The functional role of DNA methylation of Tnf was further confirmed by in vitro luciferase transcriptional activity assay. In addition, the DNA methylation level in a group of inflammatory genes was decreased in the AOM+DSS group but restored by curcumin and was validated by pyrosequencing. This study shows for the first time epigenomic changes in DNA CpG methylation in the inflammatory response from colitis-associated colon cancer and the reversal of their CpG methylation changes by curcumin. Future clinical epigenetic studies with curcumin in inflammation-associated colon cancer would be warranted.

SOX9 indirectly regulates CEACAM1 expression and immune resistance in melanoma cells

As melanoma cells are immunogenic, they instigate an adaptive immune response and production of anti-tumor T-cells. A central factor in this interaction is CEACAM1 (carcinoembryonic antigen cell adhesion molecule 1), a transmembrane glycoprotein previously shown in our lab to protect melanoma cells from T cell-mediated killing. In this study, we examine the role of transcription factor SOX9 in the regulation of CEACAM1 expression and immune resistance in melanoma cells. Knockdown of endogenous SOX9 results in CEACAM1 up-regulation, while its overexpression leads to the opposite effect. We show that SOX9 controls CEACAM1 expression at a transcriptional level, but in an indirect manner, as regulation of the CEACAM1 promoter remains intact even when all eight potential SOX9-binding sites are abolished. A series of promoter truncations localizes the SOX9-controlled area to the proximal 200bp of the promoter. Point mutations in putative Sp1 and ETS1 binding sites identify these transcription factors as the primary SOX9-controlled mediators. Co-immunoprecipitation studies show that SOX9 and Sp1 physically interact in melanoma cells, while silencing of SOX9 down-regulates ETS1, but not Sp1, in the same cells. Finally, knockdown of SOX9 indeed renders melanoma cells resistant to T cell-mediated killing, in line with the increased CEACAM1 expression. In conclusion, we show that SOX9 regulates CEACAM1 expression in melanoma cells, and thereby their immune resistance. As CEACAM1 is a pivotal protein in melanoma biology and immune crosstalk, further understanding of its regulation can provide new insights and contribute to the development of novel approaches to therapy.

Transcription factor decoy: a pre-transcriptional approach for gene downregulation purpose in cancer

Gene therapy as a therapeutic approach has been the dream for many scientists around the globe. Many strategies have been proposed and applied for this purpose, yet the void for a functional safe method is still apparent. Since most of the diseases are caused by undesirable upregulation (oncogenes) or downregulation (tumor suppressor genes) of genes, major gene therapy's techniques affect gene expression. Most of the methods are used in post-transcriptional level such as RNA inhibitory (RNAi) and splice-switching oligonucleotides (SSOs). RNAi blocks messenger RNA (mRNA) translation by mRNA degradation or interruption between attachments of mRNA with ribosomes' subunits. However, one of the novel methods is the usage of transcription factor targeted decoys. DNA decoys are the new generation of functional gene downregulatory oligonucleotides which compete with specific binding sites of transcription factors. Considering the exponential growth of this technique in both in vitro and in vivo studies, in this paper, we aim to line out the description, design, and application of decoys in research and therapy.

The microRNA-27a: ZBTB10-specificity protein pathway is involved in follicle stimulating hormone-induced VEGF, Cox2 and survivin expression in ovarian epithelial cancer cells

Previously, we demonstrated that follicle stimulating hormone (FSH) enhanced VEGF expression and facilitated ovarian cancer angiogenesis via the PI3K/AKT signaling pathway. In this study, we further investigated the involvement of microRNA-27a: ZBTB10‑specificity protein pathway in the mechanism of FSH-induced VEGF, Cox2 and survivin expression. Treatment with FSH resulted in significant increase in the expression of VEGF, Cox2, survivin, Sp1 proteins and microRNA-27a in a dose-dependent manner, whereas reverse protein expression pattern was observed in ZBTB10. Downregulation of microRNA-27a using antisense microRNA-27a blocked FSH-induced VEGF, Cox2 and survivin expression. Overexpression of ZBTB10 also attenuated the FSH-induced expression of these molecules. The enhanced expression of VEGF, Cox2 and survivin was also abolished by knocking down Sp1 using small interfering RNA. Collectively, these results indicated that stimulation of ovarian cancer cell VEGF, Cox2 and survivin expression by FSH involves the microRNA‑27a: ZBTB10-specificity protein pathway.

Sensitive detection of pathway perturbations in cancers

Background

The normal functioning of a living cell is characterized by complex interaction networks involving many different types of molecules. Associations detected between diseases and perturbations in well-defined pathways within such interaction networks have the potential to illuminate the molecular mechanisms underlying disease progression and response to treatment.

Results

In this paper, we present a computational method that compares expression profiles of genes in cancer samples to samples from normal tissues in order to detect perturbations of pre-defined pathways in the cancer. In contrast to many previous methods, our scoring function approach explicitly takes into account the interactions between the gene products in a pathway. Moreover, we compute the sub-pathway that has the highest score, as opposed to merely computing the score for the entire pathway. We use a permutation test to assess the statistical significance of the most perturbed sub-pathway. We apply our method to 20 pathways in the Netpath database and to the Global Cancer Map of gene expression in 18 cancers. We demonstrate that our method yields more sensitive results than alternatives that do not consider interactions or measure the perturbation of a pathway as a whole. We perform a sensitivity analysis to show that our approach is robust to modest changes in the input data. Our method confirms numerous well-known connections between pathways and cancers.

Conclusions

Our results indicate that integrating differential gene expression with the interaction structure in a pathway is a powerful approach for detecting links between a cancer and the pathways perturbed in it. Our results also suggest that even well-studied pathways may be perturbed only partially in any given cancer. Further analysis of cancer-specific sub-pathways may shed new light on the similarities and differences between cancers.

Inflammation-induced up-regulation of TLR2 expression in human endothelial cells is independent of differential methylation in the TLR2 promoter CpG island

Toll-like receptors play an important role in endothelial inflammation; however, little is known on the mechanisms regulating their expression. Differential promoter DNA methylation is an increasingly recognized mechanism that determines a switch between gene silencing and gene transcription. We hypothesized that epigenetic mechanisms are involved in the regulation of endothelial TLR2 expression because of the localization of the TLR2 promoter on a CpG-island. Resting human umbilical vein endothelial cells (HUVECs) displayed rather low TLR2 mRNA expression, while a strong expression increase occurred under inflammatory conditions. We examined the TLR2 promoter methylation pattern in resting HUVECs and compared it to cells treated either with the inflammatory cytokine TNF-α or the DNA-demethylating agent 5-azacytidine. DNA bisulfite conversion was followed by either genomic sequencing or single nucleotide primer extension (SNuPE) HPLC. Results of both techniques showed a low- or non-methylated TLR2 promoter in resting HUVECs and no alteration of the methylation pattern under inflammatory conditions. Whereas 5-azacytidine significantly increased the mRNA expression of the epigenetically regulated gene H19, TLR2 expression was not affected. Taken together, employing different methodological approaches, our data show no implication of methylation pattern changes in inflammatory induction of TLR2 expression in human endothelial cells.

Lipopolysaccharide-induced miR-1224 negatively regulates tumour necrosis factor-α gene expression by modulating Sp1

The innate immune response provides the initial defence mechanism against infection by other organisms. However, an excessive immune response will cause damage to host tissues. In an attempt to identify microRNAs (miRNAs) that regulate the innate immune response in inflammation and homeostasis, we examined the differential expression of miRNAs using microarray analysis in the spleens of mice injected intraperitoneally with lipopolysaccharide (LPS) and saline, respectively. Following challenge, we observed 19 miRNAs up-regulated (1.5-fold) in response to LPS. Among these miRNAs, miR-1224, whose expression level increased 5.7-fold 6 hr after LPS injection and 2.3-fold after 24 hr, was selected for further study. Tissue expression patterns showed that mouse miR-1224 is highly expressed in mouse spleen, kidney and lung. Transfection of miR-1224 mimics resulted in a decrease in basal tumour necrosis factor-α (TNF-α) promoter reporter gene activity and a down-regulation of LPS-induced TNF-α mRNA in RAW264.7 cells. With public databases of miRNA target prediction, miR-1224 was shown to bind to the 3' untranslated region (UTR) of Sp1 mRNA, whose coding product controls TNF-α expression at the transcriptional level. Furthermore, we found that in HEK-293 cells, the activity of the luciferase reporter bearing Sp1 mRNA 3' UTR was down-regulated significantly when transfected with miR-1224 mimics. After transfection of miR-1224 in RAW264.7 cells, nucleus Sp1 protein level decreased, and when endogenous miR-1224 was blocked, the decrease was abolished. Therefore, we initially speculated that miR-1224 was a negative regulator of TNF-α in an Sp1-dependent manner, which was confirmed in vivo by chromatin immunoprecipitation assay, and might be involved in regulating the LPS-mediated inflammatory responses.

Simvastatin impairs murine melanoma growth

Background

Statins induces cell cycle arrest, apoptosis, reduction of angiogenic factors, inhibition of the endothelial growth factor, impairing tissue adhesion and attenuation of the resistance mechanisms. The aim of this study was evaluate the anti-tumoral activity of simvastatin in a B16F10 melanoma-mouse model.

Methods

Melanoma cells were treated with different concentrations of simvastatin and assessed by viability methods. Melanoma cells (5 × 10⁴) were implanted in two month old C57Bl6/J mice. Around 7 days after cells injection, the oral treatments were started with simvastatin (5 mg/kg/day, p.o.). Tumor size, hematological and biochemical analyses were evaluated.

Results

Simvastatin at a concentration of 0.8 μM, 1.2 μM and 1.6 μM had toxic effect. Concentration of 1.6 μM induced a massive death in the first 24 h of incubation. Simvastatin at 0.8 μM induces early cell cycle arrest in G0/G1, followed by increase of hypodiploidy. Tumor size were evaluated and the difference of treated group and control, after ten days, demonstrates that simvastatin inhibited the tumor expansion in 68%.

Conclusion

Simvastatin at 1.6 μM, presented cytototoxicity after 72 h of treatment, with an intense death. In vivo, simvastatin being potentially useful as an antiproliferative drug, with an impairment of growth after ten days.

Platelet-activating factor receptor (PAF-R)-dependent pathways control tumour growth and tumour response to chemotherapy

Background

Phagocytosis of apoptotic cells by macrophages induces a suppressor phenotype. Previous data from our group suggested that this occurs via Platelet-activating factor receptor (PAF-R)-mediated pathways. In the present study, we investigated the impact of apoptotic cell inoculation or induction by a chemotherapeutic agent (dacarbazine, DTIC) on tumour growth, microenvironmental parameters and survival, and the effect of treatment with a PAF-R antagonist (WEB2170). These studies were performed in murine tumours: Ehrlich Ascitis Tumour (EAT) and B16F10 melanoma.

Methods

Tumour growth was assessed by direct counting of EAT cells in the ascitis or by measuring the volume of the solid tumour. Parameters of the tumour microenvironment, such as the frequency of cells expressing cyclo-oxygenase-2 (COX-2), caspase-3 and galectin-3, and microvascular density, were determined by immunohistochemistry. Levels of vascular endothelium growth factor (VEGF) and prostaglandin E2 (PGE2) were determined by ELISA, and levels of nitric oxide (NO) by Griess reaction. PAF-R expression was analysed by immunohistochemistry and flow cytometry.

Results

Inoculation of apoptotic cells before EAT implantation stimulated tumour growth. This effect was reversed by in vivo pre-treatment with WEB2170. This treatment also reduced tumour growth and modified the microenvironment by reducing PGE2, VEGF and NO production. In B16F10 melanoma, WEB2170 alone or in association with DTIC significantly reduced tumour volume. Survival of the tumour-bearing mice was not affected by WEB2170 treatment but was significantly improved by the combination of DTIC with WEB2170. Tumour microenvironment elements were among the targets of the combination therapy since the relative frequency of COX-2 and galectin-3 positive cells and the microvascular density within the tumour mass were significantly reduced by treatment with WEB2170 or DTIC alone or in combination. Antibodies to PAF-R stained the cells from inside the tumour, but not the tumour cells grown in vitro. At the tissue level, a few cells (probably macrophages) stained positively with antibodies to PAF-R.

Conclusions

We suggest that PAF-R-dependent pathways are activated during experimental tumour growth, modifying the microenvironment and the phenotype of the tumour macrophages in such a way as to favour tumour growth. Combination therapy with a PAF-R antagonist and a chemotherapeutic drug may represent a new and promising strategy for the treatment of some tumours.

Norcantharidin is a small-molecule synthetic compound with anti-angiogenesis effect

AIMS

This study examined the in vitro and in vivo angiogenic effects of norcantharidin (NCTD), a synthetic, small-molecule antitumor compound.

MAIN METHODS

Syngeneic colorectal adenocarcinoma CT26 cells were implanted in mice to examine the effect of NCTD on VEGF production and renal and hepatic toxicity. Human umbilical endothelial cells (HUVECs) were used to examine the in vitro effect of NCTD on viability, chemotaxis, vascular network tube formation, adhesive ability, anoikis, and mitogen-activated protein kinase (MAPK) signaling. A protein array was used for analysis of angiogenic factors released from NCTD-treated HUVECs.

KEY FINDINGS

NCTD suppressed plasma VEGF levels of tumor-bearing mice, without renal or hepatic toxicity. In vitro, NCTD inhibited viability of normal HUVECs to a lesser extent than CT26 cancer cells. At concentrations less than those inhibiting 50% of the cells, NCTD inhibited migration and capillary-like tube formation of HUVECs. The anti-angiogenic effect of NCTD was accompanied by anoikis, down-regulation of integrin beta1, and breakdown of vimentin. NCTD decreased MAPK expression of phosphorylated (p)-JNK and p-ERK. P-P38 expression or P38 inhibitor SB203580 did not impair the effect of NCTD on viability or adhesion of HUVECs. In addition, NCTD inhibited the release of pro-angiogenic factors from HUVECs, but not from CT26 cells.

SIGNIFICANCE

NCTD is a synthetic, small-molecule compound possessing anti-angiogenetic activity with potential use in anti-cancer therapy as an anti-metastatic and anti-angiogenic agent.

Induction of endogenous gamma-globin gene expression with decoy oligonucleotide targeting Oct-1 transcription factor consensus sequence

Human β-globin disorders are relatively common genetic diseases cause by mutations in the β-globin gene. Increasing the expression of the γ-globin gene has great benefits in reducing complications associated with these diseases. The Oct-1 transcription factor is involved in the transcriptional regulation of the γ-globin gene. The human γ-globin genes (both Aγ and Gγ-globin genes) carry three Oct-1 transcription factor consensus sequences within their promoter regions. We have studied the possibility of inducing γ-globin gene expression using decoy oligonucleotides that target the Oct-1 transcription factor consensus sequence. A double-stranded 22 bp decoy oligonucleotide containing the Oct-1 consensus sequence was synthesized. The results obtained from our in vitro binding assay revealed a strong competitive binding of the decoy oligonucleotide for the Oct-1 transcription factor. When K562 human erythroleukemia cells were treated with the Oct-1 decoy oligonucleotide, significant increases in the level of the γ-globin mRNA were observed. The results of our western blots further demonstrated significant increases of the fetal hemoglobin (HbF, α2γ2) in the Oct-1 decoy oligonucleotide-treated K562 cells. The results of our immunoprecipitation (IP) studies revealed that the treatment of K562 cells with the Oct-1 decoy oligonucleotide significantly reduced the level of the endogenous γ-globin gene promoter region DNA co-precipitated with the Oct-1 transcription factor. These results suggest that the decoy oligonucleotide designed for the Oct-1 transcription factor consensus sequence could induce expression of the endogenous γ-globin gene through competitive binding of the Oct-1 transcription factor, resulting in activation of the γ-globin genes. Therefore, disrupting the bindings of the Oct-1 transcriptional factors with the decoy oligonucleotide provides a novel approach for inducing expression of the γ-globin genes. It also provides an innovative strategy for the treatment of many disease conditions, including sickle cell anemia and β-thalassemia.

M-CSF signals through the MAPK/ERK pathway via Sp1 to induce VEGF production and induces angiogenesis in vivo

Background

M-CSF recruits mononuclear phagocytes which regulate processes such as angiogenesis and metastases in tumors. VEGF is a potent activator of angiogenesis as it promotes endothelial cell proliferation and new blood vessel formation. Previously, we reported that in vitro M-CSF induces the expression of biologically-active VEGF from human monocytes.

Methodology and Results

In this study, we demonstrate the molecular mechanism of M-CSF-induced VEGF production. Using a construct containing the VEGF promoter linked to a luciferase reporter, we found that a mutation reducing HIF binding to the VEGF promoter had no significant effect on luciferase production induced by M-CSF stimulation. Further analysis revealed that M-CSF induced VEGF through the MAPK/ERK signaling pathway via the transcription factor, Sp1. Thus, inhibition of either ERK or Sp1 suppressed M-CSF-induced VEGF at the mRNA and protein level. M-CSF also induced the nuclear localization of Sp1, which was blocked by ERK inhibition. Finally, mutating the Sp1 binding sites within the VEGF promoter or inhibiting ERK decreased VEGF promoter activity in M-CSF-treated human monocytes. To evaluate the biological significance of M-CSF induced VEGF production, we used an in vivo angiogenesis model to illustrate the ability of M-CSF to recruit mononuclear phagocytes, increase VEGF levels, and enhance angiogenesis. Importantly, the addition of a neutralizing VEGF antibody abolished M-CSF-induced blood vessel formation.

Conclusion

These data delineate an ERK- and Sp1-dependent mechanism of M-CSF induced VEGF production and demonstrate for the first time the ability of M-CSF to induce angiogenesis via VEGF in vivo.

Lack of toxicity of a STAT3 decoy oligonucleotide

BACKGROUND

STAT3 overexpression has been detected in several cancers including head and neck squamous cell carcinoma (HNSCC). Previous studies using intratumoral administration of a STAT3 decoy oligonucleotide that abrogates STAT3-mediated gene transcription in preclinical cancer models have demonstrated antitumor efficacy. This study was conducted to observe the toxicity and biologic effects of the STAT3 decoy in a non-human primate model, in anticipation of initiating a clinical trial in HNSCC patients.

METHODS

Three study groups (two monkeys/sex/group) were administered a single intramuscular injection of low dose of STAT3 decoy (0.8 mg total dose/monkey), high dose of STAT3 decoy (3.2 mg total dose/monkey) or vehicle control (PBS alone) on day 1 and necropsies were performed on days 2 and 15 (one monkey/sex/group/day). Low and high doses of the decoy were administered in the muscle in a volume of 0.9 ml. Tissue and blood were harvested for toxicology and biologic analyses.

RESULTS

Upon observation, the STAT3 decoy-treated animals exhibited behavior that was similar to the vehicle control group. Individual animal body weights remained within 1% of pretreatment weights throughout the study. Hematological parameters were not significantly different between the control and the treatment groups. Clinical chemistry fluctuations were considered within normal limits and were not attributed to the STAT3 decoy. Assessment of complement activation breakdown product (Bb) levels demonstrated no activation of the alternative pathway of complement in any animal at any dose level. At necropsy, there were no gross or microscopic findings attributed to STAT3 decoy in any organ examined. STAT3 target gene expression at the injection site revealed decreased Bcl-X(L) and cyclin D1 expression levels in the animals treated with high dose of STAT3 decoy compared to the animals injected with low dose of STAT3 decoy or the vehicle as control.

CONCLUSION

Based on these findings, the no-observable-adverse-effect-level (NOAEL) was greater than 3.2 mg/kg when administered as a single dose to male and female Cynomolgus monkeys. Plans are underway to test the safety and biologic effects of intratumoral administration of the STAT3 decoy in HNSCC patients.

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?

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.

Effects of high intensity focused ultrasound on vascular endothelial growth factor in melanoma bearing mice

This study was to investigate the effects of high intensity focused ultrasound on vascular endothelial growth factor. A B16 melanoma model was adopted in our study. Melanoma bearing mice were randomly divided into two groups: HIFU group and surgery group. While the control group was only injected with isovolumetric normal saline solution and treated as the surgery group. We detected VEGF both in tissues and sera through immunohistochemical method and ELISA respectively. Tissues were sampled pre- and at the 3rd day post-operation in HIFU group and blood samples were taken pre- and at the 1st, 3rd, and 7th day post-operation in all the groups. As a result, in the tissues, VEGF was expressed in 80% melanomas, but none was detected in the targeted area after HIFU treatment. In the sera, there was a decreasing tendency of serum-VEGF concentrations in group HIFU and surgery after operation, while that in the control group increased after operation. The levels in the HIFU group on day 1, 3, and 7 postoperatively were all lower than that in the surgery group respectively (79.16 pg/ml vs 91.59 pg/ml; 33.64 pg/ml vs 49.39 pg/ml; 30.37 pg/ml vs 46.68 pg/ml), but there wasn't any significant difference (P > 0.05). So HIFU can destroy VEGF in the targeted area and maybe have less of an effect on serum-VEGF than surgery.

Inhibitory effect of caffeic acid phenethyl ester on angiogenesis, tumor invasion, and metastasis

Caffeic acid phenethyl ester (CAPE) derived from honeybee propolis has been used as a folk medicine and has several proven biological activities. The present study investigated the effect of CAPE on angiogenesis, tumor invasion, and metastasis. A cytotoxicity assay of CAPE in CT26 colon adenocarcinoma cells showed a dose-dependent decrease in cell viability but no significant influence on the growth of human umbilical vein epithelial cells (HUVEC). A low concentration of CAPE (1.5 microg/mL) inhibited 52.7% of capillary-like tube formation in HUVEC culture on Matrigel. CAPE (6 microg/mL)-treated CT26 cells showed not only inhibited cell invasion by 47.8% but also decreased expression of matrix metalloproteinase (MMP)-2 and -9. Vascular endothelial growth factor (VEGF) production from CT26 cells was also inhibited by treatment with CAPE (6 microg/mL). Intraperitoneal injection of CAPE (10 mg/kg/day) in BALB/c mice reduced the pulmonary metastatic capacity of CT26 cells accompanied with a decreased plasma VEGF level. CAPE treatment also prolonged the survival of mice implanted with CT26 cells. These results indicate that CAPE has potential as an antimetastatic agent.