Epigenetic reprogramming in cancer: From diagnosis to treatment.

Disruption of the epigenetic program of gene expression is a hallmark of cancer that initiates and propagates tumorigenesis. Altered DNA methylation, histone modifications and ncRNAs expression are a feature of cancer cells. The dynamic epigenetic changes during oncogenic transformation are related to tumor heterogeneity, unlimited self-renewal and multi-lineage differentiation.

Cytotoxicity potential of chemical constituents isolated and derivatised from Rhinella marina venom.

Chemical compounds from skin secretions from toads of Bufonidae family have been long-studied. In the search for new molecules with pharmacological action, the 3β-OH groups of bufadienolides are commonly derivatised using acetyl groups. This work described the isolation and/or structural elucidation of isolated and derivatised compounds from the venom of the Brazilian anuran Rhinella marina, and their evaluation in in vitro assays.

Response of preantral follicles exposed to quinoxaline: A new compound with anticancer potential.

The culture of preantral follicles as an in vitro model to evaluate the toxicity of new anticancer drug has being established. Therefore, the aim of this study was to evaluate the effect of quinoxaline derivative the 2 2- (XYZC 6H 3 -CH=N-NH)-quinoxaline, 1 (QX) on caprine preantral follicles. We evaluate the follicular morphology and activation, proliferation and apoptosis of granulosa cells and finally the protein (ABCB1) and genes expression (cyclin/Cdks), respectively involved in multidrug resistance and cell cycle progression.

Synthesis of PJOV56, a new quinoxalinyl-hydrazone derivative able to induce autophagy and apoptosis in colorectal cancer cells, and related compounds.

Quinoxaline derivatives are reported as antineoplastic agents against a variety of human cancer cell lines, with some compounds being submitted to clinical trials. In this work, we report the synthesis, characterization and cytotoxicity potential of a new series of quinoxalinyl-hydrazones. The most cytotoxic compound was (E)-2-[2-(2-pyridin-2-ylmethylene)hydrazinyl]quinoxaline (PJOV56) that presented a time-dependent effect against HCT-116 cells.

Natural products as new antimitotic compounds for anticancer drug development.

Cell cycle control genes are frequently mutated in cancer cells, which usually display higher rates of proliferation than normal cells. Dysregulated mitosis leads to genomic instability, which contributes to tumor progression and aggressiveness. Many drugs that disrupt mitosis have been studied because they induce cell cycle arrest and tumor cell death.

Marinobufagin, a molecule from poisonous frogs, causes biochemical, morphological and cell cycle changes in human neoplasms and vegetal cells.

Skin toad secretion present physiologically active molecules to protect them against microorganisms, predators and infections. This work detailed the antiproliferative action of marinobufagin on tumor and normal lines, investigate its mechanism on HL-60 leukemia cells and its toxic effects on Allium cepa meristematic cells. Initially, cytotoxic action was assessed by colorimetric assays.