Broad-spectrum Anticancer Activity Research Articles

Antiproliferative activity of cycloalkanecarboxamide derivatives possessing sulfonate or sulfamate moiety.

A series of cycloalkanecarboxamide-containing sulfonate and sulfamate derivatives were prepared, and their antiproliferative activity was tested against NCI-60 cancer cell lines panel. Compound 1f possessing cyclohexyl and p-(tert-butyl)benzenesulfonate moieties was the most active among all the target compounds. It exerted broad-spectrum anticancer activity against all the nine cancer types involved in the NCI-60 panel. Additionally, compound 1g containing cyclohexyl and p-fluorobenzenesulfonate moieties was the most potent against HT29 colon cancer cell line (IC50=4.73µM) with selectivity index more than 4.23 towards HT29 than normal fibroblasts. It exerts its antiproliferative activity against HT29 through the induction of apoptosis (increasing caspase 3/7 activity) but not necrosis. Structure-activity relationship studies are presented in detail.

Chalcomoracin inhibits cell proliferation and increases sensitivity to radiotherapy in human non-small cell lung cancer cells via inducing endoplasmic reticulum stress-mediated paraptosis.

Chalcomoracin (CMR) is a kind of Diels–Alder adduct extracted from the mulberry leaves. Recent studies showed that CMR has a broad spectrum of anticancer activities and induces paraptosis in breast cancer and prostate cancer cells. In this study, we investigated the effects of CMR against human non-small cell lung cancer cells and the underlying mechanisms. We found that CMR dose-dependently inhibited the proliferation of human lung cancer H460, A549 and PC-9 cells. Furthermore, exposure to low and median doses of CMR induced paraptosis but not apoptosis, which was presented as the formation of extensive cytoplasmic vacuolation with increased expression of endoplasmic reticulum stress markers, Bip and Chop, as well as activation of MAPK pathway in the lung cancer cells. Knockdown of Bip with siRNA not only reduced the cell-killing effect of CMR, but also decreased the percentage of cytoplasmic vacuoles in H460 cells. Moreover, CMR also increased the sensitivity of lung cancer cells to radiotherapy through enhanced endoplasmic reticulum stress. In lung cancer H460 cell xenograft nude mice, combined treatment of CMR and radiation caused greatly enhanced tumor growth inhibition with upregulation of endoplasmic reticulum stress proteins and activation of pErk in xenograft tumor tissue. These data demonstrate that the anticancer activity and radiosensitization effect of CMR result from inducing paraptosis, suggesting that CMR could be considered as a potential anticancer agent and radiation sensitizer in the future cancer therapeutics.

β-Elemene inhibits the metastasis of multidrug-resistant gastric cancer cells through miR-1323/Cbl-b/EGFR pathway

Backgroundβ-Elemene is a natural agent extracted from the traditional Chinese herbal medicine Curcuma wenyujin that is a promising novel plant-derived drug with broad-spectrum anticancer activity. Our previous study identified an enhanced capacity for metastasis in multidrug resistant (MDR) gastric cancer and breast cancer cells. However, the anti-metastatic effects of β-Elemene on MDR cancer cells remain unknown. PurposeIn this study, we posit the hypothesis that β-elemene possesses antimetastatic effects on MDR cancer cells. MethodsCell viability assay was used to assess the resistance of SGC7901/ADR cells and the cytotoxic effects of β-Elemene. Wound healing, transwell assay and lung metastatic mice model were used to the anti-metastasis effects of β-Elemene. MicroRNA microarray analysis was used to explore potential regulated miRNAs. Luciferase reporter assay was used to identify the direct target. Human MMP antibody array, western blot, immunoprecipitation, qRT-PCR analyses and immunohistochemistry were conducted to investigate the underlying anti-metastasis mechanism of β-Elemene. ResultsIn this study, we found that β-Elemene significantly inhibited the metastatic capacity of MDR gastric cells in vivo and in vitro. Mechanistically, we found that β-Elemene regulated MMP-2/9 expression and reversed epithelial-mesenchymal transition. Further studies showed that β-Elemene upregulated Cbl-b expression, resulting in inhibition of the EGFR-ERK/AKT pathways, which regulate MMP-2/9. Additionally, we confirmed that β-Elemene upregulated Cbl-b by inhibiting miR-1323 expression. Finally, we found that numbers of metastatic tumor nodules were significantly decreased in the lungs of nude mice after β-Elemene treatment. ConclusionOur results suggested that β-Elemene inhibits the metastasis of MDR gastric cancer cells by modulating the miR-1323/Cbl-b/EGFR signaling axis.

Peruvoside targets apoptosis and autophagy through MAPK Wnt/β-catenin and PI3K/AKT/mTOR signaling pathways in human cancers

AimTo investigate the cytotoxic effect of Peruvoside and mechanism of action in human cancers. Main methodsCell viability was measured by MTT assay and the cell cycle arrest was identified by FACS. Real-time qPCR and western blotting studies were performed to identify important gene and protein expressions in the different pathways leading to apoptosis. Immunofluorescence was performed to understand protein localization and molecular docking studies were performed to identify protein-ligand interactions. Key findingsPeruvoside showed significant anti-proliferative activities against human breast, lung, and liver cancer cells in dose-dependent manner. The anti-cancer mechanism was further confirmed by DNA damage and cell cycle arrest at the G0/G1 phase. Dysregulation of Wnt/β-catenin signaling with Peruvoside treatment resulted in inhibition of cyclin D1 and c-Myc also observed in this study. Furthermore, we identified that Peruvoside can inhibit autophagy by PI3K/AKT/mTOR signaling and through downregulating MEK1. Moreover, Peruvoside has the ability to modulate the expressions of key proteins from the cell cycle, MAPK, NF-kB, and JAK-STAT signaling. In silico studies revealed that Peruvoside has the ability to interact with crucial proteins from different biochemical signaling pathways. SignificanceOur results demonstrated that Peruvoside has the ability to inhibit cancer cell proliferation by modulating the expression of various key proteins involved in cell cycle arrest, apoptosis, and autophagic cell death. Clinical data generated from the present study might provide a novel impetus for targeting several human cancers. Conclusively, our findings suggest that the Peruvoside possesses a broad spectrum of anticancer activity in breast, lung, and liver cancers, which provides an impetus for further investigation of the anticancer potentiality of this biomolecule.

Design, Synthesis, and Structural Characterization of Novel Diazaphenothiazines with 1,2,3-Triazole Substituents as Promising Antiproliferative Agents.

A series of novel 1,2,3-triazole-diazphenothiazine hybrids was designed, synthesized, and evaluated for anticancer activity against four selected human tumor cell lines (SNB-19, Caco-2, A549, and MDA-MB231). The majority of the synthesized compounds exhibited significant potent activity against the investigated cell lines. Among them, compounds 1d and 4c showed excellent broad spectrum anticancer activity, with IC50 values ranging from 0.25 to 4.66 μM and 0.25 to 6.25 μM, respectively. The most promising compound 1d, possessing low cytotoxicity against normal human fibroblasts NHFF, was used for gene expression analysis using reverse transcription–quantitative real-time PCR (RT–qPCR). The expression of H3, TP53, CDKN1A, BCL-2, and BAX genes revealed that these compounds inhibited the proliferation in all cells (H3) and activated mitochondrial events of apoptosis (BAX/BCL-2).

Identification of HUHS190, a human naftopidil metabolite, as a novel anti-bladder cancer drug

We carried out structure-activity relationship study on anti-cancer effects of naftopidil (1) and its metabolites, resulted in identification of 1-(4-hydroxy-2-methoxyphenyl)piperazin-1-yl)-3-(naphthalen-1-yloxy) propan-2-ol (2, HUHS190), a major human metabolite of 1, which exhibited the most selective toxicities between against normal and cancer cells (Table 1). 2 was more hydrophilic compared to 1, was enough to be prepared in high concentration solution of more than 100 μM in saline for an intravesical instillation drug. Moreover, serum concentration of 2 was comparable to that of 1, an oral preparation drug, after oral administration at 32 mg/kg (Fig. 3). Both of 1 and 2 showed broad-spectrum anti-cancer activities in vitro, for example, 1 and 2 showed inhibitory activity IC50 = 21.1 μM and 17.2 μM for DU145, human prostate cancer cells, respectively, and IC50 = 18.5 μM and 10.5 μM for T24 cells, human bladder cancer cells. In this study, we estimated anticancer effects of 2 in a bladder cancer model after intravesical administration similar to clinical cases. A single intravesical administration of 2 exhibited the most potent inhibitory activities among the clinical drugs for bladder cancers, BCG and Pirarubicin, without obvious side effects and toxicity (Fig. 4). Thus, HUHS190 (2) can be effective for patients after post-TURBT therapy of bladder cancer without side effects, unlike the currently available clinical drugs.

Alpinumisoflavone Inhibits Tumor Growth and Metastasis in Papillary Thyroid Cancer via Upregulating miR-141-3p.

Alpinumisoflavone (AIF) as a principal active ingredient of traditional Chinese herb Derris eriocarpa exerts a broad spectrum of anticancer activities against solid tumors. However, little is known about the effect of AIF on papillary thyroid cancer (PTC). Objectives of this study are to investigate the effect of AIF on cell growth, apoptosis, and metastasis of PTC cells and uncover its underlying mechanisms. Results showed that AIF treatment notably suppressed cell viability, migration, invasion, and epithelial-mesenchymal transition (EMT) process, as well as induced apoptotic cell death. In addition, microarray analysis results revealed that miR-141-3p level was dramatically elevated upon AIF insulation, suggesting that miR-141-3p may mediate the suppressive role of AIF against PTC. Moreover, miR-141-3p knockdown effectively reversed the effects of AIF on cell growth, migration, invasion, and EMT, while promoted PTC cell apoptosis escape. Furthermore, in vivo findings also confirmed that the antigrowth and antimetastasis activities of AIF were, at least partly, mediated by upregulation of miR-141-3p. Overall, AIF could serve as a potential anticancer compound for PTC treatment. Anat Rec, 2019. © 2019 American Association for Anatomy Anat Rec, 303:1842-1850, 2020. © 2019 American Association for Anatomy.

Design, Synthesis and in vitro Anticancer Evaluation of New 2H-benzo[b][1,4]thiazin-3(4H)-one Based 1,2,3-Triazoles

A series of novel 2H-benzo[b][1,4]thiazin-3(4H)-one derived from 1,4-disubstituted 1,2,3-triazole derivatives (4a-j and 5a-j) were synthesized using Cu(I) catalyzed azide alkyne cyclization (CuAAC) reaction of the compounds 2 and 3 with various aromatic azides. The examination of in vitro anticancer activity revealed that the compounds 4d and 5d were found to possess a broad spectrum of anticancer activity against three cell lines MCF-7, HeLa and IMR-32 with IC50 values ranging from 26.28 ± 1.5 to 32.06 ± 0.3 M mL-1, respectively. The remaining compounds have shown good to moderate activity against the tested cell lines.

Antitumor Effects and Related Mechanisms of Ethyl Acetate Extracts of Polygonum perfoliatum L.

Polygonum perfoliatum L. belongs to the genus Polygonaceae and has a long history to be used as a Chinese medicinal herb to reduce swelling, control body temperature, and promote detoxification. However, its anticancer activity and mechanisms of action have not been evaluated yet. In the present study, we used several cell lines and xenograft models from different cancers to demonstrate the broad-spectrum anticancer activity of P. perfoliatum L as well as its underlying mechanisms of action in vitro and in vivo. The ethyl acetate extract of P. perfoliatum L showed good anticancer activity and was further fractioned to obtain five active components, including PEA to PEE. Among these fractions, PEC showed the strongest cytotoxicities against various cancer cell lines. It was further observed that PEC inhibited cancer cell growth, arrested cells at G2 phase, and induced apoptosis in vitro and suppressed tumor growth and angiogenesis in vivo in a dose- and time-dependent manner. Furthermore, PEC decreased the expression of vascular endothelial growth factor (VEGF) and micro-vascular density (MVD) in tumor tissues in vivo. It also promoted the proliferation of T and B lymphocytes, increased the activities of natural killer (NK) cells and cytotoxic T lymphocytes (CTLs), enhanced the secretion of interleukin 2 (IL-2) by spleen cells, and raised the levels of IgG, IgG2a, and IgG2b antibodies in tumor-bearing mice in vivo, which were at least partially responsible for the anticancer activity of PEC. In summary, PEC has shown broad-spectrum anticancer activities without causing any host toxicity in vitro and in vivo and may be developed as a preventive and therapeutic agent against human cancer. Further studies are urgently needed to determine the anticancer compounds in PEC and their detailed molecular mechanisms.

New Pyrimidines and Triazolopyrimidines as Antiproliferative and Antioxidants with Cyclooxygenase-1/2 Inhibitory Potential

Aim: Cyclooxygenase-2 (COX-2) inhibition and scavenging-free radicals are important targets in cancer treatment. Materials & methods: Sulfanylpyrimidines and triazolopyrimidines were synthesized and evaluated as anticancer and antioxidant COX-1/2 inhibitors. Results: Compound 7 showed the same growth inhibitory activity as 5-fluorouracil against MCF-7. Compound 6f displayed broad-spectrum anticancer activity against the four tested cancer cell lines. Compounds 5b, 6a, 6c, 6d and 8 were found to be more active antioxidants than trolox. Compounds 6a, 6c, 6f and 8 revealed high COX-2 inhibitory activity and selectivity, which was confirmed by docking studies. Conclusion: Compound 6f could be considered as promising anticancer and antioxidant structural lead with COX-2 inhibition that deserve further derivatization and investigation.

Green synthesis of silver nanoparticles via Cynara scolymus leaf extracts: The characterization, anticancer potential with photodynamic therapy in MCF7 cells.

In this study, we report on the synthesis of silver nanoparticles (AgNPs) from the leaf extracts of Cynara scolymus (Artichoke) using microwave irradiation and the evaluation of its anti-cancer potential with photodynamic therapy (PDT). Silver nanoparticles formation was characterized by scanning electron microscopy with energy dispersive x-ray spectroscopy and Fourier transform infrared (FTIR) spectroscopy. Silver nanoparticles formation was also investigated the surface charge, particle size and distribution using zetasizer analysis. The cytotoxic effect of AgNPs and/or PDT was studied by MTT assay and migration by the scratch assay. The apoptotic inducing ability of the AgNPs and/or PDT was investigated by intracellular ROS analysis, antioxidant enzyme levels (SOD, CAT, GPx and GSH), Hoechst staining and Bax/Bcl-2 analysis using western blotting. The mean particle size of produced AgNPs was found 98.47±2.04 nm with low polydispersity (0.301±0.033). Zeta potential values of AgNPs show -32.3± 0.8 mV. These results clearly indicate the successful formation of AgNPs for cellular uptake. Mitochondrial damage and intracellular ROS production were observed upon treatment with AgNPs (10μg/mL) and PDT (0.5 mJ/cm2) showed significant reducing cell migration, expression of Bax and suppression of Bcl-2. Significantly, biosynthesized AgNPs showed a broad-spectrum anti-cancer activity with PDT therapy and therefore represent promoting ROS generation by modulating mitochondrial apoptosis induction in MCF7 breast cancer cells.

Interactions between β-Lactoglobulin and 3,3'-Diindolylmethane in Model System.

The compound 3,3′-diindolylmethane (DIM) has a broad spectrum of anticancer activities. However, low stability and bioavailability limit its application. Elucidating interactions between DIM and β-lactoglobulin (β-LG) may be useful for fabricating whey protein-based protecting systems. Interaction with DIM increased the diameter and absolute zeta potential value of β-LG. UV-absorption spectra suggested that there was a complex of DIM and β-LG. β-LG showed enhanced fluorescence intensity by complexing with DIM with a binding constant of 6.7 × 105 M−1. Upon interaction with DIM, β-LG was decreased in secondary structure content of helix and turn while increased in β-sheet and unordered. FT-IR spectra and molecular docking results indicated the roles of hydrophobic interaction and hydrogen bond for the formation of DIM and β-LG nanocomplexes. Data suggested that β-LG may be a good vehicle for making a protein-based DIM protection and delivery system due to the tight binding of DIM to β-LG.

Antimicrobial Peptides: Potential Application in Liver Cancer.

The physicochemical properties of antimicrobial peptides (AMPs) including size, net charge, amphipathic structure, hydrophobicity, and mode-of-action together determine their broad-spectrum activities against bacteria, fungi, protozoa, and viruses. Recent studies show that some AMPs have both antimicrobial and anticancer activities, suggesting a new strategy for cancer therapy. Hepatocellular carcinoma (HCC), the primary liver cancer, is a leading cause of cancer mortality worldwide, and lacks effective treatment. Anticancer peptides (ACPs) derived from AMPs or natural resources could be applied to combat HCC directly or as a synergistic treatment. However, the number of known ACPs is low compared to the number of antibacterial and antifungal peptides, and very few of them can be applied clinically for HCC treatment. In this review, we first summarize recent studies related to ACPs for HCC, followed by a description of potential modes-of-action including direct killing, anti-inflammation, immune modulation, and enhanced wound healing. We then describe the structures of AMPs and methods to design and modify these peptides to improve their anticancer efficacy. Finally, we explore the potential application of ACPs as vaccines or nanoparticles for HCC treatment. Overall, ACPs display several attractive properties as therapeutic agents, including broad-spectrum anticancer activity, ease-of-design and modification, and low production costs. As this is an emerging and novel area of cancer therapy, additional studies are needed to identify existing candidate AMPs with ACP activity, and assess their anticancer activity and specificity, and immunomodulatory effects, using in vitro, in silico, and in vivo approaches.

Design, Synthesis, and Anticancer Activities of Benzofuran–Isatin Hybrids Tethered by Pentylene and Hexylene

Fourteen benzofuran–isatin hybrids 6a–f and 7a–h tethered via alkyl linker (pentylene and hexylene) were designed and synthesized, and hybrids 6c–f and 7a–h were screened for their in vitro anticancer activity against various human cancer cell lines. The majority of the hybrids were active against the tested cancer cells, and the most active hybrids 7g (half maximal inhibitory concentration/IC50: 77.2–88.9 μM) and 7h (IC50: 65.4–89.7 μM), which possessed broad spectrum anticancer activity were as potent as the reference vorinostat (IC50: 64.2–>100 μM) against all tested cancer cell lines, could act as leads for further investigations. The structure–activity relationship is also discussed, and the enriched structure–activity relationship may afford useful information for further rational design of the candidates with higher activity.

Preclinical Pharmacokinetics of Fosciclopirox, a Novel Treatment of Urothelial Cancers, in Rats and Dogs

Pharmacokinetic studies in rats and dogs were performed to characterize the in vivo performance of a novel prodrug, fosciclopirox. Ciclopirox olamine (CPX-O) is a marketed topical antifungal agent with demonstrated in vitro and in vivo preclinical anticancer activity in several solid tumor and hematologic malignancies. The oral route of administration for CPX-O is not feasible due to low bioavailability and dose-limiting gastrointestinal toxicities. To enable parenteral administration, the phosphoryl-oxymethyl ester of ciclopirox (CPX), fosciclopirox (CPX-POM), was synthesized and formulated as an injectable drug product. In rats and dogs, intravenous CPX-POM is rapidly and completely metabolized to its active metabolite, CPX. The bioavailability of the active metabolite is complete following CPX-POM administration. CPX and its inactive metabolite, ciclopirox glucuronide (CPX-G), are excreted in urine, resulting in delivery of drug to the entire urinary tract. The absolute bioavailability of CPX following subcutaneous administration of CPX-POM is excellent in rats and dogs, demonstrating the feasibility of this route of administration. These studies confirmed the oral bioavailability of CPX-O is quite low in rats and dogs compared with intravenous CPX-POM. Given its broad-spectrum anticancer activity in several solid tumor and hematologic cancers and renal elimination, CPX-POM is being developed for the treatment of urothelial cancer. The safety, dose tolerance, pharmacokinetics, and pharmacodynamics of intravenous CPX-POM are currently being characterized in a United States multicenter first-in-human Phase 1 clinical trial in patients with advanced solid tumors (NCT03348514).

Synthesis of Gold(I) Complexes Containing Cinnamide: In Vitro Evaluation of Anticancer Activity in 2D and 3D Spheroidal Models of Melanoma and In Vivo Angiogenesis.

A series of alkynylgold(I) phosphine complexes containing methoxy-substituted cinnamide moieties (3a-3c and 4a-4c) have been synthesized and characterized. All of the synthesized complexes were evaluated for their cytotoxicity against three human cancer cell lines A549 (lung), D24 (melanoma), and HT1080 (fibrosarcoma) and the human embryonic kidney 293 cell line (Hek293T) as a proxy model for noncancer cells. Most of the synthesized compounds showed antiproliferative activity against cancer cell lines at low micromolar concentrations. Among these, complex 3c showed a broad spectrum of anticancer activity with IC50 values in the range of 1.53-6.05 μM against all tested cancer lines. Complex 3c possessed 20 times higher cytotoxicity than the reference drug cisplatin against D24 melanoma cells and showed significant anticancer activity in 3D spheroidal models of melanoma cells. Mechanistic investigations of 3c activity indicate thioredoxin reductase inhibition through steric and hydrogen-bonding interactions, followed by the induction of oxidative stress and a mitochondrial pathway of cell death. Compound 3c also showed significant antiangiogenic properties in a transgenic zebrafish Tg(fli1a:EGFP) in vivo model.

Identification of a Novel Anti-cancer Protein, FIP-bbo, from Botryobasidium botryosum and Protein Structure Analysis using Molecular Dynamic Simulation

Fungal immunoregulatory proteins (FIP) are effective small molecule proteins with broad-spectrum immunomodulatory and anti-cancer activities and can be potential agents for the development of clinical drugs and health food additives. In this study, a new member of FIP named FIP-bbo was obtained through Botryobasidium botryosum genome mining. FIP-bbo has the typical characteristics of FIP but is genetically distant from other FIPs. Recombinant FIP-bbo (rFIP-bbo) was produced in an optimized E. coli expression system, and the pure protein was isolated using a Ni-NTA column. Antineoplastic experiments suggested that FIP-bbo is similar to LZ-8 in inhibiting various cancer cells (Hela, Spac-1, and A549) at lower concentrations, but it is not as potent as LZ-8. The molecular mechanism by which FIP-bbo, FIP-fve, and LZ-8 are cytotoxic to cancer cells has been discussed based on molecular dynamics simulation. Point mutations that may improve the thermal stability of FIP-fve and FIP-bbo were predicted. These results not only present a new candidate protein for the development of anticancer adjuvants, but also provide an approach for designing FIPs with high anticancer activity.

Synthesis and biological evaluation of purine-pyrazole hybrids incorporating thiazole, thiazolidinone or rhodanine moiety as 15-LOX inhibitors endowed with anticancer and antioxidant potential

Novel purine-pyrazole hybrids combining thiazoles, thiazolidinones and rhodanines, were designed and tested as 15-LOX inhibitors, potential anticancer and antioxidant agents. All tested compounds were found to be potent 15-LOX inhibitors with IC50 ranging from 1.76 to 6.12 µM. The prepared compounds were evaluated in vitro against five cancer cell lines: A549 (lung), Caco-2 (colon), PC3 (prostate), MCF-7 (breast) and HepG-2 (liver). Compounds 7b and 8b displayed broad spectrum anticancer activity against the five tested cell lines (IC50 = 18.5–95.39 µM). While, compound 7h demonstrated moderate anticancer activity against lung A549 and colon Caco-2 cell lines. Antioxidant screening revealed that six compounds (5a, 5b, 6b, 7b, 7h and 8b) with IC50 ranging from 0.93 to 14.43 µg/ml were found to be more potent scavengers of 2,2- diphenyl-1-picrylhydrazyl (DPPH) than the reference ascorbic acid with IC50 value of 15.34 µg/ml. Compounds 7b, 7h and 8b, when evaluated for their antioxidant activity, where found to be potent DPPH scavengers. Moreover, compound 7b displayed twice the potency of ascorbic acid as NO scavenger. Docking study was performed to elucidate the possible binding mode of the most active compounds with the active site of 15-LOX enzyme. Collectively, the purine-pyrazole hybrids having thiazoline or thizolidinone moieties (7b, 7h and 8b) constitute a promising scaffold in designing more potent 15-LOX inhibitors with anticancer and antioxidant potential.

Antimicrobial garlic-derived diallyl polysulfanes: Interactions with biological thiols in Bacillus subtilis

BackgroundDiallylpolysulfanes are the key constituents of garlic oils, known to exhibit broad spectrum anticancer and antimicrobial activity. Studies in vitro, and in mammalian cells, have shown they react, via thiol-polysulfane exchange, with their major low molecular weight thiol, glutathione. However, there are no detailed reports of diallylpolysulfane effects on other common thiol metabolites (cysteine and coenzyme A) or major thiol cofactors (e.g. bacillithiol) that many Gram positive bacteria produce instead of glutathione. MethodsDiallylpolysulfanes were individually purified then screened for antimicrobial activity against Bacillus subtilis. Their impact on thiol metabolites (bacillithiol, cysteine, coenzyme A, protein thiols allyl thiols//persulfides) in B. subtilis cultures were analysed, by HPLC. ResultsDiallylpolysulfane bioactivity increased with increasing chain length up to diallyltetrasulfane, but then plateaued. Within two minutes of treating B. subtilis with diallyltrisulfane or diallyltetrasulfane intracellular bacillithiol levels decreased by ~90%. Cysteine and CoA were also affected but to a lesser degree. This was accompanied by the accumulation of allyl thiol and allyl persulfide. A significant level of protein-S-allylation was also detected. ConclusionsIn addition to the major low molecular weight thiol, diallylpolysulfanes can also have an impact on other thiol metabolites and protein thiols. General significanceThis study shows the rapid parallel impact of polysulfanes on different biological thiols inside Bacillus subtilis alongside the concomitant generation of allyl thiols and persulfides.

MDA-7/IL-24 regulates the miRNA processing enzyme DICER through downregulation of MITF

Melanoma differentiation-associated gene-7/interleukin-24 (mda-7/IL-24) is a multifunctional cytokine displaying broad-spectrum anticancer activity in vitro or in vivo in preclinical animal cancer models and in a phase 1/2 clinical trial in patients with advanced cancers. mda-7/IL-24 targets specific miRNAs, including miR-221 and miR-320, for down-regulation in a cancer-selective manner. We demonstrate that mda-7/IL-24, administered through a replication incompetent type 5 adenovirus (Ad.mda-7) or with His-MDA-7/IL-24 protein, down-regulates DICER, a critical regulator in miRNA processing. This effect is specific for mature miR-221, as it does not affect Pri-miR-221 expression, and the DICER protein, as no changes occur in other miRNA processing cofactors, including DROSHA, PASHA, or Argonaute. DICER is unchanged by Ad.mda-7/IL-24 in normal immortal prostate cells, whereas Ad.mda-7 down-regulates DICER in multiple cancer cells including glioblastoma multiforme and prostate, breast, lung, and liver carcinoma cells. MDA-7/IL-24 protein down-regulates DICER expression through canonical IL-20/IL-22 receptors. Gain- and loss-of-function studies confirm that overexpression of DICER rescues deregulation of miRNAs by mda-7/IL-24, partially rescuing cancer cells from mda-7/IL-24-mediated cell death. Stable overexpression of DICER in cancer cells impedes Ad.mda-7 or His-MDA-7/IL-24 inhibition of cell growth, colony formation, PARP cleavage, and apoptosis. In addition, stable overexpression of DICER renders cancer cells more resistant to Ad.mda-7 inhibition of primary and secondary tumor growth. MDA-7/IL-24-mediated regulation of DICER is reactive oxygen species-dependent and mediated by melanogenesis-associated transcription factor. Our research uncovers a distinct role of mda-7/IL-24 in the regulation of miRNA biogenesis through alteration of the MITF-DICER pathway.