New water-soluble hypoxia activated 7-aminoquinoxaline 1,4-dioxides, prepared by the regioselective Beirut reaction, acted as HIF-1α suppressors and induced apoptosis in hypoxic and MDR cancer cells.

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A series of 3-aryl/hetarylquinoxaline-2-carbonitrile-1,4-dioxides was synthesized and evaluated against breast cancer cell lines in normoxia and hypoxia. Selected compounds in this series demonstrated better cytotoxicity and comparable hypoxia selectivity than tirapazamine. In contrast to Dox, quinoxaline-1,4-dioxides showed potent cytotoxicity against different MDR cells. Compound 2g inhibits of cancer cell growth through p53-independent mechanisms. Our results showed that compound 2g sensitized MCF-7 cells to metformin in hypoxia. Treatment with 2g results in the increase of ROS accumulation in cancer cells. Compound 2g can be considered as the lead compound for further anticancer drug design, evaluation, and development of new potent antitumor agents.

Background: Quinoxaline 1,4-dioxides have a broad range of biological activity that causes a growing interest in their derivatives for drug discovery. Recent studies demonstrated that quinoxaline 1,4- dioxides have a promising anticancer activity and good hypoxia-selectivity. Objective: The preparation, isolation, structure characterization, and screening for anticancer activity of the first representatives of 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides have been described. Material and Method: A series of 7- and 6-halogeno-3-phenylquinoxaline-2-carbonitrile 1,4-dioxides was synthesized by the Beirut reaction. The cytotoxicity was assessed by MTT test (72 h incubation) in normoxia (21% O2) and hypoxia (1% O2) conditions. Results: We found that during the Beirut reaction between a benzofuroxan bearing an electron withdrawing group and benzoylacetonitrile in the presence of triethylamine, in addition to well-known 7-substituted quinoxaline-2-carbonitrile 1,4-dioxides 7-11a, the 6-isomers 7-11b are formed. Moreover, the yield of the 6- isomers increased with the increase in the electron-withdrawing character of the substituent. For benzofuroxans with CO2Me and CF3 groups, 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides 10-11b were the major products. Despite similarities in physicochemical and spectroscopic properties, the obtained isomers exhibit considerable differences in their anticancer activity and hypoxia selectivity. Conclusion: Substituents and their electronic effects play a key role in the formation of 7- and 6-substituted quinoxaline-2-carbonitrile 1,4-dioxides in the Beirut reaction and in the cytotoxicity properties of the obtained isomers.

The emergence of drug resistance in pathogens leads to a loss of effectiveness of antimicrobials and complicates the treatment of bacterial infections. Quinoxaline 1,4-dioxides represent a prospective scaffold for search of new compounds with improved chemotherapeutic characteristics. Novel 2-acyl-3-trifluoromethylquinoxaline 1,4-dioxides with alteration of substituents at position 2 and 6 were synthesized via nucleophilic substitution with piperazine moiety and evaluated against a broad panel of bacteria and fungi by measuring their minimal inhibitory concentrations. Their mode of action was assessed by whole-genomic sequencing of spontaneous drug-resistant Mycobacterium smegmatis mutants, followed by comparative genomic analysis, and on an original pDualrep2 system. Most of the 2-acyl-3-trifluoromethylquinoxaline 1,4-dioxides showed high antibacterial properties against Gram-positive strains, including mycobacteria, and the introduction of a halogen atom in the position 6 of the quinoxaline ring further increased their activity, with 13c being the most active compound. The mode of action studies confirmed the DNA-damaging nature of the obtained quinoxaline 1,4-dioxides, while drug-resistance may be provided by mutations in redox homeostasis genes, encoding enzymes potentially involved in the activation of the compounds. This study extends views about the antimicrobial and antifungal activities of the quinoxaline 1,4-dioxides and can potentially lead to the discovery of new antibacterial drugs.

Background: DNAseq, RNAseq and determination of microsatellite instability (MSI) are now routine analyses in precision medicine for management of cancer patients. Analyzing DNA/RNA requires reliable assays often performed in two separate runs. Faced with limited quantity of total nucleic acids (TNA) extracted from FFPE this can be challenging. Sequential approaches (i.e. DNAseq followed by RNAseq) increase the turnaround time and cost, delaying treatment. Here, we evaluated a novel NGS approach developed by Invitae (San Francisco, USA). Using TNA from FFPE tissue, we detected SNVs, indels, MSI and structural rearrangements in one single NGS run.Methods: 24 samples from patients with various cancers were included, previously characterized using conventional methods: DNAseq, RNAseq, PCR, IHC or FISH. The study was approved by ICL ethical and scientific committee-all patients gave their consent. FFPE samples were qualified, selected followed by tumor cell content evaluation by a pathologist. After microdissection, TNAs were extracted and libraries were prepared using a parallel VariantPlex (DNA) and FusionPlex (RNA) kit from Invitae. Kits were designed to detect known and novel fusions in gene targets commonly encountered in solid tumors, MSI, and variants using a panel of 156 cancer-relevant target genes (71 DNA, 136 RNA).Results: Among 9 previous SNVs/indels and 11 MSI samples identified by orthogonal methods, NGS approach confirmed all (100%). Among 12 fusions, 11 were detected by NGS (91.7%). Single ROS1 fusion scored low (1+) using IHC. Further analyses are conducted to determine whether the ROS1 fusion is false positive by IHC, or false negative by NGS.Conclusions: Novel, all-in-one NGS approach from Invitae shows promising results by comprehensively detecting SNVs, indels, MSI and structural variants. Analyses of DNA and RNA using the novel NGS strategy improves the overall turn-around-time and cost-effectiveness. This can potentially aid clinicians and patients to take timely decisions regarding treatment modalities.

In this study, the in vitro antimicrobial, antiparasitic, antiproliferative and cytotoxic activities of essential oil from Baccharis parvidentata Malag. (EO-Bp) and Lippia origanoides Kunth (EO-Lo) were explored. The relevant effects were observed against the parasitic protozoans Plasmodium falciparum, Trypanosoma cruzi, Trypanosoma brucei and Leishmania amazonensis (ranging 0.6 to 39.7 µg/mL) and malignant MCF-7, MCF-7/HT, 22Rv1, and A431 cell lines (ranging 6.1 to 31.5 µg/mL). In parallel, EO-Bp showed better selective indexes in comparison with EO-Lo against peritoneal macrophages from BALB/c mice and MRC-5 cell line. In conclusion, EO-Lo is known to show a wide range of health benefits that could be added as another potential use of this oil with the current study. In the case of EO-Bp, the wide spectrum of its activities against protozoal parasites and malignant cells, as well as its selectivity in comparison with non-malignant cells, could suggest an interesting candidate for further tests as a new therapeutic alternative.

assay using flow cytometry. Data analysis was done using the software CellQuestPro. Results and discussions Our study results demonstrated that the methanol extract of Holothuria scabra exhibited cytotoxic activity through inhibiting the growth of T47D cancer cells in a dose-dependent manner, start from 50 mg/mL until 500 mg/ mL, with IC 50 value of 152.98 mg/mL. The methanol extract of Holothuria scabra was able to stimulate 99% cancer cells to undergo apoptosis. This data warrant for further investigation on that apoptotic mechanism. The investigation is important to support cancer therapeutical strategies that focus on inducing cell death to overcome apoptosis resistance, one of the most important hallmark of cancer. Conclusion The methanol extract of Holothuria scabra contains a promising anti-cancer agent that possesses cytotoxic and apoptotic effects on breast cancer cells.