Physciosporin suppresses mitochondrial respiration, aerobic glycolysis, and tumorigenesis in breast cancer.

BACKGROUND: Physciosporin (PHY) is one of the potent anticancer lichen compound. Recently, PHY was shown to suppress colorectal cancer cell proliferation, motility, and tumorigenesis through novel mechanisms of action. PURPOSE: We investigated the effects of PHY on energy metabolism and tumorigenicity of the human breast cancer (BC) cells MCF-7 (estrogen and progesterone positive BC) and MDA-MB-231 (triple negative BC). METHODS: The anticancer effect of PHY on cell viability, motility, cancer metabolism and tumorigenicity was evaluated by MTT assay, migration assay, clonogenic assay, anchorage-independent colony formation assay, glycolytic and mitochondrial metabolism analysis, qRT-PCR, flow cytometric analysis, Western blotting, immunohistochemistry in vitro; and by tumorigenicity study with orthotopic breast cancer xenograft model in vivo. RESULTS: PHY markedly inhibited BC cell viability. Cell-cycle profiling and Annexin V-FITC/PI double staining showed that a toxic dosage of PHY triggered apoptosis in BC cell lines by regulating the B-cell lymphoma-2 (Bcl-2) family proteins and the activity of caspase pathway. At non-toxic concentrations, PHY potently decreased migration, proliferation, and tumorigenesis of BC cells in vitro. Metabolic studies revealed that PHY treatment significantly reduced the bioenergetic profile by decreasing respiration, ATP production, and glycolysis capacity. In addition, PHY significantly altered the levels of mitochondrial (PGC-1α) and glycolysis (GLUT1, HK2 and PKM2) markers, and downregulated transcriptional regulators involved in cancer cell metabolism, including ß-catenin, c-Myc, HIF-1α, and NF-κB. An orthotopic implantation mouse model of BC confirmed that PHY treatment suppressed BC growth in vivo and target genes were consistently suppressed in tumor specimens. CONCLUSION: The findings from our in vitro as well as in vivo studies exhibit that PHY suppresses energy metabolism as well as tumorigenesis in BC. Especially, PHY represents a promising therapeutic effect against hormone-insensitive BC (triple negative) by targeting energy metabolism.

Deoxypodophyllotoxin Exerts Anti-Cancer Effects on Colorectal Cancer Cells Through Induction of Apoptosis and Suppression of Tumorigenesis.

Deoxypodophyllotoxin (DPT) is a cyclolignan compound that exerts anti-cancer effects against various types of cancers. DPT induces apoptosis and inhibits the growth of breast, brain, prostate, gastric, lung, and cervical tumors. In this study, we sought to determine the effect of DPT on cell proliferation, apoptosis, motility, and tumorigenesis of three colorectal cancer (CRC) cell lines: HT29, DLD1, and Caco2. DPT inhibited the proliferation of these cells. Specifically, the compound-induced mitotic arrest in CRC cells by destabilizing microtubules and activating the mitochondrial apoptotic pathway via regulation of B-cell lymphoma 2 (Bcl-2) family proteins (increasing Bcl-2 associated X (BAX) and decreasing B-cell lymphoma-extra-large (Bcl-xL)) ultimately led to caspase-mediated apoptosis. In addition, DPT inhibited tumorigenesis in vitro, and in vivo skin xenograft experiments revealed that DPT significantly decreased tumor size and tumor weight. Taken together, our results suggest DPT to be a potent compound that is suitable for further exploration as a novel chemotherapeutic for human CRC.

Physciosporin suppresses the proliferation, motility and tumourigenesis of colorectal cancer cells.

BACKGROUND: Lichens, which represent symbiotic associations of fungi and algae, are potential sources of numerous natural products. Physciosporin (PHY) is a potent secondary metabolite found in lichens and was recently reported to inhibit the motility of lung cancer cells via novel mechanisms. PURPOSE: The present study investigated the anticancer potential of PHY on colorectal cancer (CRC) cells. METHODS: PHY was isolated from lichen extract by preparative TLC. The effect of PHY on cell viability, motility and tumourigenicity was elucidated by MTT assay, hoechst staining, flow cytometric analysis, transwell invasion and migration assay, soft agar colony formation assay, Western blotting, qRT-PCR and PCR array in vitro as well as tumorigenicity study in vivo. RESULTS: PHY decreased the viability of various CRC cell lines (Caco2, CT26, DLD1, HCT116 and SW620). Moreover, PHY elicited cytotoxic effects by inducing apoptosis at toxic concentrations. At non-toxic concentrations, PHY dose-dependently suppressed the invasion, migration and colony formation of CRC cells. PHY inhibited the motility of CRC cells by suppressing epithelial-mesenchymal transition and downregulating actin-based motility markers. In addition, PHY downregulated ß-catenin and its downstream target genes cyclin-D1 and c-Myc. Moreover, PHY modulated KAI1 C-terminal-interacting tetraspanin and KAI1 expression, and downregulated the downstream transcription factors c-jun and c-fos. Finally, PHY administration showed considerable bioavailability and effectively decreased the growth of CRC xenografts in mice without causing toxicity. CONCLUSION: PHY suppresses the growth and motility of CRC cells via novel mechanisms.

Tumidulin, a Lichen Secondary Metabolite, Decreases the Stemness Potential of Colorectal Cancer Cells.

Lichens produce various unique chemicals that are used in the pharmaceutical industry. To screen for novel lichen secondary metabolites that inhibit the stemness potential of colorectal cancer cells, we tested acetone extracts of 11 lichen samples collected in Chile. Tumidulin, isolated from Niebla sp., reduced spheroid formation in CSC221, DLD1, and HT29 cells. In addition, mRNA expressions and protein levels of cancer stem markers aldehyde dehydrogenase-1 (ALDH1), cluster of differentiation 133 (CD133), CD44, Lgr5, and Musashi-1 were reduced after tumidulin treatment. Tumidulin decreased the transcriptional activity of the glioma-associated oncogene homolog zinc finger protein (Gli) promoter in reporter assays, and western blotting confirmed decreased Gli1, Gli2, and Smoothened (SMO) protein levels. Moreover, the tumidulin activity was not observed in the presence of Gli and SMO inhibitors. Together, these results demonstrate for the first time that tumidulin is a potent inhibitor of colorectal cancer cell stemness.

Acetonic extracts of the endolichenic fungus EL002332 isolated from Endocarpon pusillum exhibits anticancer activity in human gastric cancer cells.

BACKGROUND: Endolichenic fungi are microbes that inhabit the thalli of lichens and produce various unique chemicals that can be used for pharmaceutical purposes. PURPOSE: This study screened a library of endolichenic fungal extracts to identify novel anticancer agents capable of suppressing the tumorigenicity of human cancer cells. METHODS: Active compounds were isolated from extracts of endolichenic fungi by column chromatography and reverse-phase HPLC. The anticancer effects of the extracts on cell viability was assessed with the use of MTT assay, Western blotting, fluorescence labeling of apoptotic cell, and flow cytometric analysis; and cell motility with the use of migration, invasion and soft agar colony-formation assay in vitro; and on skin and intraperitoneal mouse xenograft tumors in vivo were investigated. The therapeutic effects of the extract alone or in combination with the conventional chemoreagent docetaxel were analyzed by sulforhodamine B assay. RESULTS: Acetone extracts of EL002332, isolated from Endocarpon pusillum collected in the China desert in 2010, showed selective cytotoxicity against AGS human gastric cancer cells and CT26 mouse colon cancer cells. An active pure compound named myC was isolated from mycelium acetone extracts in a liquid culture system and showed more potent cytotoxicity than crude extracts in the AGS cell line. Especially, myC greatly increased the apoptotic cell population at the IC50 concentration and activated apoptotic signaling by regulating Bcl2 family protein expression and caspase pathway activity. EL002332 crude extracts and myC decreased AGS cell motility at sub-lethal concentrations. In vivo skin and intraperitoneal xenograft tumor experiments showed that the size of tumors and the tumor score were significantly smaller in EL002332 crude extract-treated groups than in control groups. EL002332 crude extracts showed synergistic effects with docetaxel on the AGS and TMK1 cell lines. CONCLUSION: The endolichenic fungus EL002332 has potential anticancer activity in gastric cancer and peritoneal carcinomatosis.