Alkaloids and Polyacetylenes from Hippobroma longiflora with Antiangiogenesis Properties.

Four new alkaloids, hippobrines A-D (1-4), along with three new polyacetylenes, hippobrenes A-C (5-7), were isolated from Hippobroma longiflora. Compounds 1-3 possess an unprecedented carbon skeleton. All of the new structures were determined by analyzing their mass and NMR spectroscopic data. The absolute configurations of 1 and 2 were confirmed by single-crystal X-ray analyses, and the absolute configurations of 3 and 7 were deduced using their ECD spectra. Plausible biogenetic pathways of 1 and 4 were proposed. In regard to bioactivities, all compounds (1-7) exhibited weak antiangiogenic activity against human endothelial progenitor cells, with IC50 values ranging from 21.1 ± 1.1 to 44.0 ± 2.3 µg/mL.

CuI-mediated synthesis of 1-aryl-5,6,7-trimethoxybenzimidazoles as potent antitubulin agents.

In situ CuI-mediated cyclization methodology helped yield benzimidazoles with different substitution manner, such as 1,2-diarylbenzimidazoles (4 and 5) and 1-arylbenzimidazoles (6-15). The result of structure-activity relationship (SAR) study confirmed the significance of the 5,6,7-trimethoxybenzimidazole moiety, and the representative derivatives (8-10) exhibited marked antiproliferative activity against A549, HCT-116, and PC-3 cells; in addition, they are able to inhibit the polymerization of tubulin. Among them, compound 10 inhibited the growth of A549, HCT-116, and PC-3 cells with a mean IC50 value of 0.07 µM, and its IC50 value of tubulin polymerization is 0.26 µM.

Correction: CuI-mediated synthesis of 1-aryl-5,6,7-trimethoxybenzimidazoles as potent antitubulin agents.

[This corrects the article DOI: 10.1039/D3RA01927F.].

Critical role of heme oxygenase-1 in chaetoglobosin A by triggering reactive oxygen species mediated mitochondrial apoptosis in colorectal cancer.

The incidence rate of colorectal cancer (CRC) has been increasing and poses severe threats to human health worldwide and developing effective treatment strategies remains an urgent task. In this study, Chaetoglobosin A (ChA), an endophytic fungal metabolite from the medicinal herb-derived fungus Chaetomium globosum Km1126, was identified as a potent and selective antitumor agent in human CRC. ChA induced growth inhibition of CRC cells in a concentration-dependent manner but did not impair the viability of normal colon cells. ChA triggered mitochondrial intrinsic and caspase-dependent apoptotic cell death. In addition, apoptosis antibody array analysis revealed that expression of Heme oxygenase-1 (HO-1) was significantly increased by ChA. Inhibition of HO-1 increased the sensitivity of CRC cells to ChA, suggesting HO-1 may play a protective role in ChA-mediated cell death. ChA induced cell apoptosis via the induction of reactive oxygen species (ROS) and ROS scavenger (NAC) prevented ChA-induced cell death, mitochondrial dysfunction, and HO-1 activation. ChA promoted the activation of c-Jun N-terminal kinase (JNK), and co-administration of JNK inhibitor or siRNA markedly reversed ChA-mediated apoptosis. ChA significantly decreased the tumor growth without eliciting any organ toxicity or affecting the body weight of the CRC xenograft mice. This is the first study to demonstrate that ChA exhibits promising anti-cancer properties against human CRC both in vitro and in vivo. ChA is a potential therapeutic agent worthy of further development in clinical trials for cancer treatment.

WISP-3 Stimulates VEGF-C-Dependent Lymphangiogenesis in Human Chondrosarcoma Cells by Inhibiting miR-196a-3p Synthesis.

Chondrosarcoma is a malignant bone tumor with high metastatic potential. Lymphangiogenesis is a critical biological step in cancer metastasis. WNT1-inducible signaling pathway protein 3 (WISP-3) regulates angiogenesis and facilitates chondrosarcoma metastasis, but the role of WISP-3 in chondrosarcoma lymphangiogenesis is unclear. In this study, incubation of chondrosarcoma cells with WISP-3 increased the production of VEGF-C, an important lymphangiogenic factor. Conditioned medium from WISP-3-treated chondrosarcoma cells significantly enhanced lymphatic endothelial cell tube formation. WISP-3-induced stimulation of VEGF-C-dependent lymphangiogenesis inhibited miR-196a-3p synthesis in the ERK, JNK, and p38 signaling pathways. This evidence suggests that the WISP-3/VEGF-C axis is worth targeting in the treatment of lymphangiogenesis in human chondrosarcoma.