Toxicogenomic and bioinformatics platforms to identify key molecular mechanisms of a curcumin-analogue DM-1 toxicity in melanoma cells.

Melanoma is a highly invasive and metastatic cancer with high mortality rates and chemoresistance. Around 50% of melanomas are driven by activating mutations in BRAF that has led to the development of potent anti-BRAF inhibitors. However resistance to anti-BRAF therapy usually develops within a few months and consequently there is a need to identify alternative therapies that will bypass BRAF inhibitor resistance. The curcumin analogue DM-1 (sodium 4-[5-(4-hydroxy-3-methoxy-phenyl)-3-oxo-penta-1,4-dienyl]-2-methoxy-phenolate) has substantial anti-tumor activity in melanoma, but its mechanism of action remains unclear. Here we use a synthetic lethal genetic screen in Saccharomyces cerevisiae to identify 211 genes implicated in sensitivity to DM-1 toxicity. From these 211 genes, 74 had close human orthologues implicated in oxidative phosphorylation, insulin signaling and iron and RNA metabolism. Further analysis identified 7 target genes (ADK, ATP6V0B, PEMT, TOP1, ZFP36, ZFP36L1, ZFP36L2) with differential expression during melanoma progression implicated in regulation of tumor progression, cell differentiation, and epithelial-mesenchymal transition. Of these TOP1 and ADK were regulated by DM-1 in treatment-naïve and vemurafenib-resistant melanoma cells respectively. These data reveal that the anticancer effect of curcumin analogues is likely to be mediated via multiple targets and identify several genes that represent candidates for combinatorial targeting in melanoma.

cirCodAn: A GHMM-based tool for accurate prediction of coding regions in circRNA.

Studies focusing on characterizing circRNAs with the potential to translate into peptides are quickly advancing. It is helping to elucidate the roles played by circRNAs in several biological processes, especially in the emergence and development of diseases. While various tools are accessible for predicting coding regions within linear sequences, none have demonstrated accurate open reading frame detection in circular sequences, such as circRNAs. Here, we present cirCodAn, a novel tool designed to predict coding regions in circRNAs. We evaluated the performance of cirCodAn using datasets of circRNAs with strong translation evidence and showed that cirCodAn outperformed the other tools available to perform a similar task. Our findings demonstrate the applicability of cirCodAn to identify coding regions in circRNAs, which reveals the potential of use of cirCodAn in future research focusing on elucidating the biological roles of circRNAs and their encoded proteins. cirCodAn is freely available at https://github.com/denilsonfbar/cirCodAn.

Metalloproteinases Suppression Driven by the Curcumin Analog DM-1 Modulates Invasion in BRAF-Resistant Melanomas.

BACKGROUND: Melanoma is the most aggressive skin cancer, and BRAF (V600E) is the most frequent mutation that led to the development of BRAF inhibitors (BRAFi). However, patients treated with BRAFi usually present recidivism after 6-9 months. Curcumin is a turmeric substance, and it has been deeply investigated due to its anti-inflammatory and antitumoral effects. Still, the low bioavailability and biodisponibility encouraged the investigation of different analogs. DM-1 is a curcumin analog and has shown an antitumoral impact in previous studies. METHODS: Evaluated DM-1 stability and cytotoxic effects for BRAFi-sensitive and resistant melanomas, as well as the role in the metalloproteinases modulation. RESULTS: DM-1 showed growth inhibitory potential for melanoma cells, demonstrated by reduction of colony formation, migration and endothelial tube formation, and cell cycle arrest. Subtoxic doses were able to downregulate important Metalloproteinases (MMPs) related to invasiveness, such as MMP-1, -2 and -9. Negative modulations of TIMP-2 and MMP-14 reduced MMP-2 and -9 activity; however, the reverse effect is seen when increased TIMP-2 and MMP-14 resulted in raised MMP-2. CONCLUSION: These findings provide essential details into the functional role of DM-1 in melanomas, encouraging further studies in the development of combinatorial treatments for melanomas.

One-pot, three-component synthesis of 7-azaindole derivatives from N-substituted 2-amino-4-cyanopyrroles, various aldehydes, and active methylene compounds.

An efficient and practical route to 7-azaindole framework has been developed by one-pot, three-component cyclocondensation of N-substituted 2-amino-4-cyanopyrroles, various aldehydes, and active methylene compounds in ethanol or acetic acid at reflux. Reactions involving tetronic acid, indane-1,3-dione, dimedone, and 5-phenylcyclohexane-1,3-dione gave carbocyclic fused 7-azaindoles, whereas Meldrum's acid, benzoylacetonitrile, and malononitrile resulted in the highly substituted 7-azaindole derivatives, making this strategy very useful in diversity-oriented synthesis (DOS).