Naphtho[1,2-b]furan-4,5-dione inhibits MDA-MB-231 cell migration and invasion by suppressing Src-mediated signaling pathways

Chemical constituents from basidiomycete Basidioradulum radula culture medium and their cytotoxic effect on human prostate cancer DU-145 cells

Eight new naphtho[1,2-c]furan derivatives (1-8) along with six known analogues (9-14) were isolated from culture medium of the basidiomycete Basidioradulum radula. The structures of these compounds were identified using spectroscopic analysis, and their absolute configurations were resolved using X-ray diffraction, ECD, and VCD. Compounds 7 and 14 inhibited the cell viability of human prostate cancer DU-145 cells with IC₅₀ values of 7.54 ± 0.03 μM and 5.04 ± 0.03 μM, respectively. At 8 μM, compounds 7 and 14 increased the percentage of apoptotic cells and upregulated the protein expression related to the apoptosis caspase pathways in DU-145 cells. Furthermore, the hallmarks of cells undergoing apoptosis, such as chromatin condensation, were also observed at this concentration. However, compound 7 and 14 showed no effect on the proliferation of splenocytes isolated from cyclophosphamide-induce immunosuppressed mice.

Synthetic Naphthofuranquinone Derivatives Are Effective in Eliminating Drug-Resistant Candida albicans in Hyphal, Biofilm, and Intracellular Forms: An Application for Skin-Infection Treatment

Candida albicans is the most common cause of fungal infection. The emergence of drug resistance leads to the need for novel antifungal agents. We aimed to design naphthofuranquinone analogs to treat drug-resistant C. albicans for topical application on cutaneous candidiasis. The time-killing response, agar diffusion, and live/dead assay of the antifungal activity were estimated against 5-fluorocytosine (5-FC)- or fluconazole-resistant strains. A total of 14 naphthofuranquinones were compared for their antifungal potency. The lead compounds with hydroxyimino (TCH-1140) or O-acetyl oxime (TCH-1142) moieties were the most active agents identified, showing a minimum inhibitory concentration (MIC) of 1.5 and 1.2 μM, respectively. Both compounds were superior to 5-FC and fluconazole for killing planktonic fungi. Naphthofuranquinones efficiently diminished the microbes inside and outside the biofilm. TCH-1140 and TCH-1142 were delivered into C. albicans-infected keratinocytes to eradicate intracellular fungi. The compounds did not reduce the C. albicans burden inside the macrophages, but the naphthofuranquinones promoted the transition of fungi from the virulent hypha form to the yeast form. In the in vivo skin mycosis mouse model, topically applied 5-FC and TCH-1140 reduced the C. albicans load from 1.5 × 10⁶ to 5.4 × 10⁵ and 1.4 × 10⁵ CFU, respectively. The infected abscess diameter was significantly decreased by TCH-1140 (3-4 mm) as compared to the control (8 mm). The disintegrated skin-barrier function induced by the fungi was recovered to the baseline by the compound. The data support the potential of TCH-1140 as a topical agent for treating drug-resistant C. albicans infection without causing skin irritation.

Avicequinone B sensitizes anoikis in human lung cancer cells

BACKGROUND

During metastasis, cancer cells require anokis resistant mechanism to survive until reach the distant secondary tissues. As anoikis sensitization may benefit for cancer therapy, this study demonstrated the potential of avicequinone B, a natural furanonaphthoquinone found in mangrove tree (Avicenniaceae) to sensitize anoikis in human lung cancer cells.

METHODS

Anoikis inducing effect was investigated in human lung cancer H460, H292 and H23 cells that were cultured in ultra-low attachment plate with non-cytotoxic concentrations of avicequinone B. Viability of detached cells was evaluated by XTT assay at 0-24 h of incubation time. Soft agar assay was performed to investigate the inhibitory effect of avicequinone B on anchorage-independent growth. The alteration of anoikis regulating molecules including survival and apoptosis proteins were elucidated by western blot analysis.

RESULTS

Avicequinone B at 4 μM significantly induced anoikis and inhibited proliferation under detachment condition in various human lung cancer cells. The reduction of anti-apoptotic proteins including anti-apoptotic protein B-cell lymphoma 2 (Bcl-2) and myeloid cell leukemia 1 (Mcl-1) associating with the diminution of integrin/focal adhesion kinase (FAK)/Proto-oncogene tyrosine-protein kinase (Src) signals were detected in avicequinone B-treated cells.

CONCLUSIONS

Avicequinone B sensitized anoikis in human lung cancer cells through down-regulation of anti-apoptosis proteins and integrin-mediated survival signaling.

Naphtho[1,2-b]furan-4,5-dione is a potent anti-MRSA agent against planktonic, biofilm and intracellular bacteria

Aim: Naphtho[1,2-b]furan-4,5-dione (N12D) and naphtho[2,3-b]furan-4,9-dione (N23D) are furanonaphthoquinone derivatives from natural resources. We examined the antimicrobial activity of N12D and N23D against drug-resistant Staphylococcus aureus. Materials & methods: Minimum inhibitory concentration, minimum bactericidal concentration, bacterial viability and agar diffusion assay were conducted against methicillin-resistant S. aureus (MRSA) and clinical isolates of vancomycin-resistant S. aureus. Results & conclusion: The minimum inhibitory concentration of N12D and N23D against MRSA was 4.9–9.8 and 39 μM, respectively. With regard to the agar diffusion test, the inhibition zone of the quinone compounds was threefold larger than that of oxacillin. N12D was found to inhibit MRSA biofilm thickness from 24 to 16 μm as observed by confocal microscopy. N12D showed a significant reduction of the intracellular MRSA burden without decreasing the macrophage viability. The antibacterial mechanisms of N12D may be bacterial wall/membrane damage and disturbance of gluconeogenesis and the tricarboxylic acid cycle.

Insulin-like growth factor binding protein-2 regulates β-catenin signaling pathway in glioma cells and contributes to poor patient prognosis

BACKGROUND

Upregulation of insulin-like growth factor binding protein 2 (IGFBP-2) is often associated with aggressiveness of glioblastoma (GBM) and contributes to poor prognosis for GBM patients. In view of the regulation of β-catenin by IGFBP-2 in breast cancer and the crucial role of β-catenin pathway in glioma invasion, proliferation and maintenance of glioma stem cells, the mechanism of regulation of β-catenin by IGFBP-2, and its role in GBM prognosis was studied.

METHODS

Regulation of the β-catenin pathway was studied by immunocytochemistry, Western blot analysis, luciferase assays, and real-time RT-PCR. The role of IGFBP-2 was studied by subcutaneous tumor xenografts in immunocompromised mice using glioma cells engineered to express IGFBP-2 and its domains. GBM patient tumor tissues (n = 112) were analyzed for expression of IGFBP-2 and β-catenin by immunohistochemistry. Survival analysis was performed employing Cox regression and Kaplan-Meier survival analyses.

RESULTS

IGFBP-2 knockdown in U251, T98G, and U373 or overexpression in LN229 and U87 cells revealed a role for IGFBP-2 in stabilization of β-catenin and regulation of its nuclear functions involving integrin-mediated inactivation of GSK3β. Similar results were obtained upon overexpression of the C-terminal domain of IGFBP-2 but not the N-terminal domain. Subcutaneous xenograft tumors overexpressing either full-length or the C-terminal domain of IGFBP-2 showed larger volume as compared with controls. Coexpression of high levels of IGFBP-2 and β-catenin was associated with worse prognosis (P = .001) in GBM patients.

CONCLUSION

IGFBP-2 potentiates GBM tumor growth by the activation of the β-catenin pathway through its C-terminal domain, and their coexpression possibly contributes to worse patient prognosis.

Copper(i)–Y zeolite catalyzed N-sulfonylketenimine mediated annulation of hydroxynaphthoquinones: syntheses of naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones

An efficient, one pot synthesis of novel naphtho[2,1-b]furan-2,5-diones and benzo[de]chromene-2,6-diones was reported using copper(i)–Y zeolite as catalyst.

Regulation of the tumor marker Fascin by the viral oncoprotein Tax of human T-cell leukemia virus type 1 (HTLV-1) depends on promoter activation and on a promoter-independent mechanism

Adult T-cell leukemia/lymphoma is a highly infiltrative neoplasia of CD4(+) T-lymphocytes that occurs in about 5% of carriers infected with the deltaretrovirus human T-cell leukemia virus type 1 (HTLV-1). The viral oncoprotein Tax perturbs cellular signaling pathways leading to upregulation of host cell factors, amongst them the actin-bundling protein Fascin, an invasion marker of several types of cancer. However, transcriptional regulation of Fascin by Tax is poorly understood. In this study, we identified a triple mode of transcriptional induction of Fascin by Tax, which requires (1) NF-κB-dependent promoter activation, (2) a Tax-responsive region in the Fascin promoter, and (3) a promoter-independent mechanism sensitive to the Src family kinase inhibitor PP2. Thus, Tax regulates Fascin by a multitude of signals. Beyond, using Tax-expressing and virus-transformed lymphocytes as a model system, our study is the first to identify the invasion marker Fascin as a novel target of PP2, an inhibitor of metastasis.

Re2O7-catalyzed formal [3 + 2] cycloaddition for diverse naphtho[1,2-b]furan-3-carboxamides and their biological evaluation

Diverse naphtho[1,2-b]furan-3-carboxamide derivatives 12a-12q were synthesized in high yield via the novel Re2O7-catalyzed formal [3 + 2] cycloaddition of 1,4-naphthoquinones with β-ketoamides as the key step. This methodology offers several advantages, such as environmentally benign character, the use of a mild catalyst, high yields, and ease of handling. The synthesized compounds were screened for their tyrosinase inhibitory, antioxidant, and antibacterial activities. The results showed that compound 12c exhibited excellent tyrosinase inhibitory activity with an IC50 of 13.48 μg/mL, which is comparable to that of kojic acid (IC50 = 19.45 μg/mL). Compounds 12a, 12b, and 12i displayed moderate antioxidant activities in a DPPH assay. Compound 12m showed good activity against S. aureus (MIC = 16 μg/mL), and compound 12p was found to be active against E. coli (MIC = 16 μg/mL).

Fruit-derived phenolic compounds and pancreatic cancer: perspectives from Australian native fruits

ETHNOPHARMACOLOGICAL RELEVANCE

Pancreatic cancer is a devastating cancer that presents late, is rapidly progressive and has current therapeutics with only limited efficacy. Bioactive compounds are ubiquitously present in fruits and numerous studies in vitro are addressing the activity of these compounds against pancreatic cancer, thus studies of specific bioactive compounds could lead to new anti-pancreatic cancer strategies. Australian native fruits have been used as foods and medicines by Australian Aboriginals for thousands of years, and preliminary studies have found these fruits to contain rich and diversified bioactive components with high antioxidant activity. Thus, Australian native fruits may possess key components for preventing or delaying the onset of tumorigenesis, or for the treatment of existing cancers, including pancreatic cancer.

MATERIALS AND METHODS

Numerous databases including PubMed, SciFinder, Web of Knowledge, Scopus, and Sciencedirect were analysed for correlations between bioactive components from fruits and pancreatic cancer, as well as studies concerning Australian native fruits.

RESULTS

In this review, we comprehensively highlight the proposed mechanisms of action of fruit bioactives as anti-cancer agents, update the potential anti-pancreatic cancer activity of various major classes of bioactive compounds derived from fruits, and discuss the existence of bioactive compounds identified from a selection Australian native fruits for future studies.

CONCLUSION

Bioactive compounds derived from fruits possess the potential for the discovery of new anti-pancreatic cancer strategies. Further, Australian native fruits are rich in polyphenols including some flora that contain unique phenolic compounds, thereby warranting further investigations into their anti-cancer properties.