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

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

YM155 induces apoptosis in p53-deficient T-acute lymphoblastic leukemia cells independent of survivin inhibition.

T-acute lymphoblastic leukemia (T-ALL) is an aggressive hematological cancer that arises from the malignant transformation of T-cell progenitors. Despite the significant progress in current treatment, challenges remain the lifelong morbidity after current chemotherapy regimens and postrelapse survival. In addition, patients with T-ALL have inferior outcomes compared with those with B-cell precursor; consequently, novel therapeutic approaches are still necessary to improve the outcome in this cohort. YM155 is an imidazolium derivative originally discovered as a suppressant of survivin expression. It has been reported that YM155 has potent antiproliferative activity on a variety of human cancer cell lines; however, its effects in T-ALL cells have been underexplored. The aim of the present study was to examine the effects of YM155 on p53-deficient T-ALL cell lines, JURKAT and CCRF-CEM. Resazurin dye was used to evaluate cell viability. Colony formation was observed in MethoCult methylcellulose medium. Apoptotic cells were detected by flow cytometry (annexin V labeling and TUNEL assay). Cell cycle analysis was carried out by DNA quantification in flow cytometry. DNA damage was assessed using a comet assay and the survivin expression profile was evaluated by real-time PCR and immunoblotting. YM155 treatment decreased cell viability and clonogenicity capacity of T-ALL cells, increased the apoptosis index and DNA damage, and altered the cell cycle dynamic, independent of survivin inhibition. Taken together, the data reinforce that YM155 may be useful as a therapeutic possibility to combat leukemia.

Zebularine induces chemosensitization to methotrexate and efficiently decreases AhR gene methylation in childhood acute lymphoblastic leukemia cells.

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in childhood. Despite the advances in treatment, about 20% of patients relapse and/or die, indicating the need for different therapies for this group. Zebularine (ZB) is a potent DNA methyltransferase (DNMT) inhibitor and has been associated with gene demethylation and enhancement of tumor chemosensitivity. This study aimed to evaluate the effects of ZB, alone or combined with chemotherapeutics (methotrexate and vincristine), on childhood ALL cell lines. Cell proliferation, apoptosis, and clonogenic capacity were studied in Jurkat and ReH cell lines. Bisulfite modification, followed by methylation-specific PCR was carried out to evaluate aryl hydrocarbon receptor (AhR) methylation status. Gene expression of DNMT1, DNMT3a, DNMT3b, and AhR was assessed using qRT-PCR. Both cell cultures were sensitive to ZB, showing a dose-dependent and time-dependent response (P<0.05). ZB induced apoptosis and decreased clonogenic capacity in both cell lines. Combination with methotrexate resulted in a strong synergistic effect, whereas combination with vincristine led to an antagonistic response in both cell lines. ZB treatment decreased gene expression of the three DNMTs and induced AhR gene promoter demethylation and its re-expression. These results indicate that ZB may be a promising drug for the adjuvant treatment of ALL, mainly when combined with methotrexate.

Suppression of inflammatory cytokine secretion by an NF-ĸB inhibitor DHMEQ in nasal polyps fibroblasts.

BACKGROUND: NF-ĸB is an essential transcription factor strongly associated to inflammatory response in chronic rhinosinusitis with nasal polyps (CRSwNP). DHMEQ is a NF-ĸB inhibitor that has been previously described with a greatpotential indecreasing inflammation in diseases other than CRSwNP. The aim of study isto evaluate the ability of DHMEQ to reducethe inflammatory recruiters on CRSwNP and to compare its anti-inflammatory profile as a single-agent or in association with fluticasone propionate (FP). METHODS: nasal polyp fibroblasts were cultured in TNF-α enriched media. Cells were submitted to three different concentrations (1, 10 and 100nM) of either FP, DHMEQ or both. Inflammatory response was accessed by VCAM-1, ICAM-1 and RANTES expression (by RTQ-PCR) and protein levels by ELISA. Nuclear translocation of NF-ĸB was also evaluated. RESULTS: both FP and DHMEQ inhibited inflammatory recruiters' production and NF-ĸB nuclear translocation. Interestingly, the anti-inflammatory effect from the association steroids plus DHMEQ was more intense than of each drug in separate. CONCLUSION: DHMEQ seems efficient in modulating the inflammatory process in CRSwNP. The synergic anti-inflammatory effect of DHMEQ and steroids may be a promising strategy to be explored, particularly in the setting of steroid-resistant NP.

In vitro effect of glucocorticoids on nasal polyps.

UNLABELLED: Glucocorticoids are considered the main treatment option for nasal polyps, but their effect is only recently being understood. AIM: To evaluate whether fluticasone propionate (FP) inhibits the inflammatory process induced by TNF-alpha in vitro, and to assess if NF-kappaB is associated to this inhibition. STUDY DESIGN: Experimental in vitro study. MATERIALS AND METHODS: Nasal polyp fibroblasts were cultured during 24 hours. Three different concentrations of FP (1, 10 and 100 nM, added to TNF-alpha) were compared to negative (without additive) and positive (TNF-alpha) controls. Gene expression (RTQ-PCR) and protein concentration (ELISA) of VCAM-1, ICAM-1, eotaxin and RANTES were measured, as well as the nuclear translocation of NF-kappaB. RESULTS: TNF-alpha significantly increased protein concentration and RNA expression of all the studied molecules, as well as the nuclear translocation of NF-kappaB, when compared to the negative control. FP decreased these parameters in a dose-dependent manner, statistically different from positive control up to 100nM. CONCLUSIONS: FP extensively inhibited inflammatory recruiters, at both protein and RNA levels, confirming the ability of glucocorticoids to modulate the inflammatory process in nasal polyps. This inhibition was associated to decreased NF-kappaB nuclear translocation, demonstrating that this is an important mechanism of glucocorticoids action for nasal polyps.

In vitro effect of glucocorticoids on nasal polyps / Efeito in vitro de glicocorticosteróides sobre pólipos nasais

Glucocorticoids are considered the main treatment option for nasal polyps, but their effect is only recently being understood. AIM: To evaluate whether fluticasone propionate (FP) inhibits the inflammatory process induced by TNF-alpha in vitro, and to assess if NF-kappaB is associated to this inhibition. STUDY DESIGN: Experimental in vitro study. MATERIALS AND METHODS: Nasal polyp fibroblasts were cultured during 24 hours. Three different concentrations of FP (1, 10 and 100 nM, added to TNF-alpha) were compared to negative (without additive) and positive (TNF-alpha) controls. Gene expression (RTQ-PCR) and protein concentration (ELISA) of VCAM-1, ICAM-1, eotaxin and RANTES were measured, as well as the nuclear translocation of NF-kappaB. RESULTS: TNF-alpha significantly increased protein concentration and RNA expression of all the studied molecules, as well as the nuclear translocation of NF-kappaB, when compared to the negative control. FP decreased these parameters in a dose-dependent manner, statistically different from positive control up to 100nM. CONCLUSIONS: FP extensively inhibited inflammatory recruiters, at both protein and RNA levels, confirming the ability of glucocorticoids to modulate the inflammatory process in nasal polyps. This inhibition was associated to decreased NF-kappaB nuclear translocation, demonstrating that this is an important mechanism of glucocorticoids action for nasal polyps.

Glicocorticoides são considerados a principal opção terapêutica para polipose nasossinusal, mas seus efeitos estão sendo descobertos apenas recentemente. OBJETIVO: Avaliar se proprionato de fluticasona (FP) inibe in vitro o processo inflamatório induzido por TNF-alfa, e se NF-kappaB está associado a esta inibição. FORMA DE ESTUDO: Experimental in vitro. MATERIAIS E MÉTODOS: Fibroblastos de pólipos nasais foram cultivados por 24 horas. Três concentrações diferentes de FP (1, 10 e 100nM, além do TNF-alfa) foram comparados a controles negativo (sem aditivo) e positivo (TNF-alfa). Expressão gênica (RTQ-PCR) concentração proteica (ELISA) de VCAM-1, ICAM-1, eotaxin e RANTES foram medidos, assim como a translocação nuclear de NF-kappaB. RESULTADOS: TNF-alfa aumentou significativamente a concentração proteica e expressão gênica de todas molé¬culas estudadas, assim como a translocação nuclear de NF-kappaB, quando comparado ao controle negativo. O FP diminuiu estes parâmetros numa forma dose-dependente, diferente estatisticamente do controle positivo até 100nM. CONCLUSÕES: O FP extensivamente inibiu os recrutadores inflamatórios, em níveis proteicos e gênicos, confirmando a habilidade dos glicocorticoides em modular o processo inflamatório na polipose nasossinusal. Esta inibição esteve associada à diminuição da translocação nuclear de NF-kappaB, demonstrando que este é um importante mecanismo de ação dos glicocorticoide na polipose nasossinusal.