Purpose: The oncoprotein KAI1 C-terminal interacting tetraspanin (KITENIN; vang-like 1) promotes cell metastasis, invasion, and angiogenesis, resulting in shorter survival times in cancer patients. Here, we aimed to determine the effects of KITENIN on the energy metabolism of human colorectal cancer cells.Experimental design: The effects of KITENIN on energy metabolism were evaluated using in vitro assays. The GEPIA web tool was used to extrapolate the clinical relevance of KITENIN in cancer cell metabolism. The bioavailability and effect of the disintegrator of KITENIN complex compounds were evaluated by LC–MS, in vivo animal assay.Results: KITENIN markedly upregulated the glycolytic proton efflux rate and aerobic glycolysis by increasing the expression of GLUT1, HK2, PKM2, and LDHA. β-catenin, CD44, CyclinD1 and HIF-1A, including c-Myc, were upregulated by KITENIN expression. In addition, KITENIN promoted nuclear PKM2 and PKM2-induced transactivation, which in turn, increased the expression of downstream mediators. This was found to be mediated through an effect of c-Myc on the transcription of hnRNP isoforms and a switch to the M2 isoform of pyruvate kinase, which increased aerobic glycolysis. The disintegration of KITENIN complex by silencing the KITENIN or MYO1D downregulated aerobic glycolysis. The disintegrator of KITENIN complex compound DKC1125 and its optimized form, DKC-C14S, exhibited the inhibition activity of KITENIN-mediated aerobic glycolysis in vitro and in vivo.Conclusions: The oncoprotein KITENIN induces PKM2-mediated aerobic glycolysis by upregulating the c-Myc/hnRNPs axis.
Marinobazzanan (1), a new bazzanane-type sesquiterpenoid, was isolated from a marine-derived fungus belonging to the genus Acremonium. The chemical structure of 1 was elucidated using NMR and mass spectroscopic data, while the relative configurations were established through the analysis of NOESY data. The absolute configurations of 1 were determined by the modified Mosher’s method as well as vibrational circular dichroism (VCD) spectra calculation and it was determined as 6R, 7R, 9R, and 10R. It was found that compound 1 was not cytotoxic to human cancer cells, including A549 (lung cancer), AGS (gastric cancer), and Caco-2 (colorectal cancer) below the concentration of 25 μM. However, compound 1 was shown to significantly decrease cancer-cell migration and invasion and soft-agar colony-formation ability at concentrations ranging from 1 to 5 μM by downregulating the expression level of KITENIN and upregulating the expression level of KAI1. Compound 1 suppressed β-catenin-mediated TOPFLASH activity and its downstream targets in AGS, A549, and Caco-2 and slightly suppressed the Notch signal pathway in three cancer cells. Furthermore, 1 also reduced the number of metastatic nodules in an intraperitoneal xenograft mouse model.
Lung cancer has the highest mortality rates worldwide. The disease is caused by environmental pollutants, smoking, and many other factors. Recent treatments include immunotherapeutics, which have shown some success; however, the search for new therapeutics is ongoing. Endolichenic fungi produce a whale of a lot of secondary metabolites, the therapeutic effects of which are being evaluated. Here, we used a crude extract and subfractions of the endolichenic fungus, Phoma sp. (EL006848), isolated from the Pseudevernia furfuracea. It was identified the fatty acid components, palmitic acid, stearic acid, and oleic acid, exist in subfractions E1 and E2. In addition, EL006848 and its fatty acids fractions suppressed benzo[a]pyrene (an AhR ligand)- induced expression of PD-L1 to inhibit the activity of multiple immune checkpoints. E2 subfraction, which had a higher fatty acid content than E1, downregulated expression of AhR/ARNT and several human transcription factors related to ESR1. Moreover, E2 showed a strong inhibitory effect on STAT3 expression and mild effect on NF-kB activity. These results suggest that fatty acids extracted from an endolichenic fungus can exert strong immunotherapeutic effects.
Colorectal cancer (CRC) is the third most deadly type of cancer in the world and continuous investigations are required to discover novel therapeutics for CRC. Induction of apoptosis is one of the promising strategies to inhibit cancers. Here, we have identified a novel compound, Libertellenone T (B), isolated from crude extracts of the endolichenic fungus from Pseudoplectania sp. (EL000327) and investigated the mechanism of action. CRC cells treated by B were subjected to apoptosis detection assays, immunofluorescence imaging, and molecular analyses such as immunoblotting and QRT-PCR. Our findings revealed that B induced CRC cell death via multiple mechanisms including G2/M phase arrest caused by microtubule stabilization and caspase-dependent apoptosis. Further studies revealed that B induced the generation of reactive oxygen species (ROS) attributed to activating the JNK signaling pathway by which apoptosis and autophagy was induced in Caco2 cells. Moreover, B exhibited good synergistic effects when combined with the well-known anticancer drug, 5-FU, and another cytotoxic novel compound D, which was isolated from the same crude extract of EL000327. Overall, Libertellenone T induces G2/M phase arrest, apoptosis, and autophagy via activating the ROS/JNK pathway in CRC. Thus, B may be a potential anticancer therapeutic against CRC that is suitable for clinical applications.
Anithiactin D (1), a 2-phenylthiazole class of natural products, was isolated from marine mudflat-derived actinomycetes Streptomyces sp. 10A085. The chemical structure of 1 was elucidated based on the interpretation of NMR and MS data. The absolute configuration of 1 was determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectral data. Anithiactin D (1) significantly decreased cancer cell migration and invasion activities at a concentration of 5 μM via downregulation of the epithelial-to-mesenchymal transition (EMT) markers in A549, AGS, and Caco-2 cell lines. Moreover, 1 inhibited the activity of Rho GTPases, including Rac1 and RhoA in the A549 cell line, suppressed RhoA in AGS and Caco-2 cell lines, and decreased the mRNA expression levels of some matrix metalloproteinases (MMPs) in AGS and Caco-2 cell lines. Thus 1, which is a new entity of the 2-phenylthiazole class of natural products with a unique aniline-indole fused moiety, is a potent inhibitor of the motility of cancer cells.