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Organic extracts of 36 species of marine algae (sixteen species of Rhodophyta, eight species of Ochrophyta and twelve species of Chlorophyta) from seven locations on the Brazilian coast were evaluated for their anti-HSV-1 and anti-HSV-2 activity resistant to Acyclovir (ACV). Activity tests in crude extracts, followed by the identification of the major compounds present, were performed for all species. The chemical profiles of all crude extracts were obtained by 1 H-NMR and 13 C-NMR spectroscopy. The percentage of extracts with antiviral activity was higher for HSV-1 (86.1%) than for HSV-2 (55.5%). The green algae Ulva fasciata and Codium decorticatum both showed the highest activity (99.9%) against HSV-1, with triacylglycerols and fatty acids as the major components. The red alga Laurencia dendroidea showed good activity against HSV-1 (97.5%) and the halogenated sesquiterpenes obtusol and (-)-elatol were identified as the major components in the extract. Against HSV-2, the green alga Penicillus capitatus (Chlorophyta) and Stypopodium zonale (Ochrophyta) were the most active (96.0 and 95.8%). Atomaric acid, a meroditerpene, was identified as the major secondary metabolite in the S. zonale extract. These results reinforce the role of seaweeds as important sources of compounds with the potential to enter into the pipeline for development of new drugs against herpes simplex.

Burkitt lymphoma (BL) is an aggressive B cell lymphoma characterized by the reciprocal translocation of the c-Myc gene with immunoglobulin genes. Recently, MYC has been shown to maintain the neoplastic state via the miR-17-92 microRNA cluster that suppresses chromatin regulatory genes and the apoptosis regulator Bim. However, the expression and prognostic impact of miR-17-92 members in pediatric BL (pBL) are unknown. Therefore, we investigated miR-17, miR-19a, miR-19b, miR-20, and miR-92a expression and prognostic impact in a series of 41 pBL samples. In addition, Bim protein expression was evaluated and compared to miR-17, miR-19a, miR-19b, miR-20, and miR-92a levels and patient outcomes. The expression of miR-17-92 members was evaluated by qPCR and Bim protein by immunohistochemistry. Log-rank test was employed to assess prognostic impact. We found that upregulated expression of miR-17 and miR-20a correlates with lack of pro-apoptotic Bim expression. Patients bearing tumors with upregulated miR-17 displayed decreased overall survival (OS), and multivariate analysis revealed that miR-17 was a significant predictor of shortened OS. Using hairpin inhibitors, we showed that inhibition of miR-17 resulted in enhanced Bim expression in a BL cell line overexpressing the miR-17-92 cluster. Our results describe for the first time miR-17, miR-19a, miR-19b, miR-20a, and miR-92a expression profiles in pBL. The prognostic impact of miR-17 should be validated in a larger series, and may provide new therapeutic avenues in the era of anti-miRNA therapy research. Additional functional studies are further required to understand the specific role of miR-17-92 cluster members in BL.

Our results suggest a significant role for miR-29s in BL pathogenesis in altering the expression of targets involved in critical cancer pathways, such as cell cycle control, apoptosis inhibition and DNA methylation. Moreover, methylation-mediated miR-29 epigenetic silencing may occur during BL development.

Tumor-derived DNA is elevated in the plasma of patients with cancer. The analysis of circulating DNA may be useful for diagnosis, prognosis evaluation, and early detection of disease recurrence. In order to investigate cf-DNA as a marker during treatment, we serially quantified total cell-free (cf) and EBV plasma DNA in 30 cases of pediatric B-non-Hodgkin lymphoma by real-time PCR. The cf-DNA levels were significantly increased in patient samples at diagnosis as compared with the healthy controls (p < 0.001). At the end of treatment, a significant decrease in plasma DNA concentration was observed as compared with values observed at diagnosis (median: 94.0 copies/mL, p = 0.001). EBV was detected by ISH in 7/30 patients. Plasma EBV DNA levels were obtained from seven EBV-positive patients (median: 1278 copies/mL), while EBV DNA was not detected in 23 EBV-negative patients and 10 healthy controls. The association between the two methods of detection was statistically significant, with 100% correlation (Kappa coefficient, p = 1). In addition, the decrease of EBV viral load was associated with therapy response. Quantification of plasma EBV DNA may become a valuable source for disease detection of pediatric EBV-associated lymphomas and for monitoring treatment response.

bThe NFAT (nuclear factor of activated T cells) family of transcription factors is composed of four calcium-responsive proteins (NFAT1 to -4). The NFAT2 (also called NFATc1) gene encodes the isoforms NFAT2␣ and NFAT2␤ that result mainly from alternative initiation exons that provide two different N-terminal transactivation domains. However, the specific roles of the NFAT2 isoforms in cell physiology remain unclear. Because previous studies have shown oncogenic potential for NFAT2, this study emphasized the role of the NFAT2 isoforms in cell transformation. Here, we show that a constitutively active form of NFAT2␣ (CA-NFAT2␣) and CA-NFAT2␤ distinctly control death and transformation in NIH 3T3 cells. While CA-NFAT2␣ strongly induces cell transformation, CA-NFAT2␤ leads to reduced cell proliferation and intense cell death through the upregulation of tumor necrosis factor alpha (TNF-␣). CA-NFAT2␤ also increases cell death and upregulates Fas ligand (FasL) and TNF-␣ in CD4 ؉ T cells. Furthermore, we demonstrate that differential roles of NFAT2 isoforms in NIH 3T3 cells depend on the N-terminal domain, where the NFAT2␤-specific N-terminal acidic motif is necessary to induce cell death. Interestingly, the NFAT2␣ isoform is upregulated in Burkitt lymphomas, suggesting an isoform-specific involvement of NFAT2 in cancer development. Finally, our data suggest that alternative N-terminal domains of NFAT2 could provide differential mechanisms for the control of cellular functions.

Burkitt lymphoma (BL) is an aggressive B-cell lymphoma more common in children comprising one third of pediatric non-Hodgkin lymphoma cases. The recent discovery in BL pathogenesis highlighted the activation of PI3K pathway in cooperation with Myc in the development of BL. In this study, we demonstrated that PI3K/Akt pathway is a target to histone deacetylase inhibitor (HDACi) in BL cells. The combination of HDACi (sodium butyrate, NaB) and chemotherapy (VP-16) inhibited 51 % of the proliferation and enhanced the blockage of the cell cycle progression at G2/M with a concurrent decrease in the S phase. Microarray profiling showed a synergistic action of NaB/VP-16 combination through the differential regulation of 1,413 genes. Comparing VP-16 treatment with the NaB/VP-16 combination, 318 genes were deregulated: 250 genes were downregulated, and 68 were upregulated when compared with untreated cells. Among these genes, six (CDKN1A, CCND1, FAS, CHEK2, MDM4, and SESN2) belong to the p53-signaling pathway. The activation of this signaling pathway is usually induced by stress signals and ultimately leads to cell cycle arrest. Besides, the inhibition of the cell growth was related to reduced Akt phosphorylation, and decrease of c-Myc protein expression by about 60 % (p ≤ 0.005). Moreover, HDACi enhanced miR-101, miR-143, and miR-145 levels in BL cell line, which were inversely associated with the levels of miR-101, miR-143, and miR-145 found to be extremely downregulated in the sample of BL patients. We highlight the fact that effective combinations of HDACis with other target drugs could improve BL therapy in the future.