S6K1 deficiency in tumor stroma impairs lung metastasis of melanoma in mice.

Accumulating data suggest that ribosomal protein S6 kinase 1 (S6K1), an effector in the mammalian target of rapamycin (mTOR) pathway, plays pleiotropic roles in tumor progression. However, to date, while the tumorigenic function of S6K1 in tumor cells has been well elucidated, its role in the tumor stroma remains poorly understood. We recently showed that S6K1 mediates vascular endothelial growth factor A (VEGF-A) production in macrophages, thereby supporting tumor angiogenesis and growth. As macrophage-derived VEGF-A is crucial for both tumor cell intravasation and extravasation across the vascular endothelium, our previous findings suggest that stromal S6K1 signaling is required for tumor metastatic spread. Therefore, we aimed to determine the impact of host S6K1 depletion on tumor metastasis using a murine model of pulmonary metastasis (S6k1-/- mice implanted with B16F10 melanoma). The ablation of S6K1 in the host microenvironment significantly reduced the metastasized B16F10 melanoma cells on the lung surface in both spontaneous and intravenous lung metastasis mouse models without affecting the incidence of metastasis to distant lymph nodes. In addition, stromal S6K1 loss decreased the number of tumor cells circulating in the peripheral blood of mice bearing B16F10 xenografts without affecting the vascular leakage induced by VEGF-A in vivo. These observations demonstrate that S6K1 signaling in host cells other than endothelial cells is required to modulate the host microenvironment to facilitate the metastatic spread of tumors via blood circulation, thus revealing its novel role in the tumor stroma during tumor progression.

Pinecone of Pinus koraiensis Inducing Apoptosis in Human Lung Cancer Cells by Activating Caspase-3 and its Chemical Constituents.

Pinecones from Pinus koraiensisSiebold & Zucc. (Pinaceae), which have historically been treated as an undesired waste by-product in the processing of seeds, have recently been shown to contain ingredients with potent biological activities, such as polyphenols exhibiting antitumor activity. With this study, we seek to broaden our understanding of antitumor compounds contained in these pinecones beyond just polyphenols. We found that the water extract of P. koraiensis pinecones exhibits significant cytotoxic activity, with IC50 values ranging from 0.62 to 1.73 mg/ml in four human lung cancer cell lines, A549, H1264, H1299, and Calu-6, irrespective of their p53 status. We also demonstrate that pinecone water extract induces apoptosis associated with caspase-3 activation in the same cancer cell lines. Chemical investigation of the pinecone water extract revealed eight main components (1 - 8), and their structures were identified as dehydroabietic acid (1), 15-hydroxy-7-oxodehydroabietic acid (2), 7ß,15-dihydroxydehydroabietic acid (3), ß-d-glucopyranosyl labda-8(17,13)-diene-(15,16)-lactone-19-oate (4), 7α,15-dihydroxydehydroabietic acid (5), (+)-(1S,2S,4R)-limonene-1,2-diol (6), sobrerol (7), and 4-hydroxybenzoic acid (8). These findings suggest a novel biological application of P. koraiensis pinecones in combatting human lung cancer, and further identify the major compounds that could contribute to this anticancer activity.

The First Identification of Cryptosporidium parvum Virus-1 (CSpV1) in Hanwoo (Bos taurus coreanae) Calves in Korea.

Cryptosporidium is an obligate coccidian parasite that causes enteric diseases in bovine species. A double-stranded RNA virus associated with C. parvum oocysts, Cryptosporidium parvum virus-1 (CSpV1), has been characterized. However, the relationship between the abovementioned coccidian parasite and the virus has not been studied in the context of the known clinical outcomes. This study aimed to characterize the prevalence and molecular traits of CSpV1 in diarrheal feces of Hanwoo (Korean indigenous cattle) calves. Of the 140 fecal samples previously tested for C. parvum, which were obtained from Hanwoo calves aged 60 days, 70 tested positive and 70 tested negative. These samples were included in this study. By using the polymerase chain reaction (PCR) analysis targeting the RdRp gene of CSpV1, we detected CSpV1 in 28 samples (20.0%), with infection rates of 31.4% (22/70) in C. parvum-positive and 8.6% (6/70) in C. parvum-negative samples. CSpV1 samples detected in the same farm were clustered together. To the best of our knowledge, this is the first study to report the prevalence and molecular characteristics of CSpV1 in Hanwoo calves in the Republic of Korea, providing important insights into the relationship between C. parvum and CSpV1 in bovine hosts.

YAP-dependent Wnt5a induction in hypertrophic adipocytes restrains adiposity.

Wnt5a, a prototypic non-canonical Wnt, is an inflammatory factor elevated in the sera of obese humans and mice. In the present study, fat-specific knockout of Wnt5a (Wnt5a-FKO) prevented HFD-induced increases in serum Wnt5a levels in male C57BL/6 J mice, which suggested adipocytes are primarily responsible for obesity-induced increases in Wnt5a levels. Mouse subcutaneous white adipose tissues (WATs) more sensitively responded to HFD, in terms of cell size increases and Wnt5a levels than epididymal WATs. Furthermore, adipocyte sizes were positively correlated with Wnt5a levels in vitro and in vivo. In hypertrophic adipocytes, enlarged lipid droplets increased cell stiffness and rearranged the f-actin stress fibers from the cytoplasm to the cortical region. The activities of YAP (Yes-associated protein) and TAZ (transcriptional co-activator with PDZ-binding motif) increased in response to these mechanical changes in hypertrophic adipocytes, and inhibition or knock-down of YAP and TAZ reduced Wnt5a expression. ChIP (chromatin immunoprecipitation) analyses revealed that YAP was recruited by Wnt5a-1 gene promoter and increased Wnt5a expression. These results suggested that YAP responds to mechanical stress in hypertrophic adipocytes to induce the expression Wnt5a. When 8-week-old Wnt5a-FKO mice were fed an HFD for 20 weeks, the fat mass increased, especially in subcutaneous WATs, as compared with that observed in floxed mice, without significant changes in food intake or activity. Furthermore, Wnt5a-FKO mice showed impaired glucose tolerance regardless of diet type. Our findings show that hypertrophy/YAP/Wnt5a signaling constitutes a negative-feedback loop that retrains adipose tissue hypertrophy.

Bioactivity-based analysis and chemical characterization of cytotoxic compounds from a poisonous mushroom, Amanita spissacea, in human lung cancer cells in vitro.

As part of our systematic study on Korean toxic mushrooms, bioactivity-guided fractionation of the MeOH extract of Amanita spissacea (Amanitaceae) fruiting bodies and chemical investigation of its cytotoxic fractions led to the isolation of (9E)-8-oxo-9-octadecenoic acid (1), (10E)-9-oxo-10-octadecenoic acid (2), (9E)-8-oxo-9-octadecenoate methyl ester (3), (9Z)-9-octadecenoate-(2'S)-2',3'-dihydroxypropyl ester (4), (9Z)-9-octadecenoic acid (5), and palmitic acid (6). The structures of the isolates were elucidated by NMR spectroscopic analysis and LC/MS analysis. Among the isolated compounds, compounds 1 and 2 exhibited the most potent cytotoxic activity in all human lung cancer cell lines examined, with IC50 values ranging from 255.7 to 321.0 µM and 250.2 to 322.5 µM, respectively. The cytotoxicity of these compounds was also found to be mediated by apoptosis associated with caspase-3 activation. These findings provide experimental evidence suggesting the potential of A. spissacea as a promising natural source for the discovery of novel anticancer drug candidates.

HIF-1α-Dependent Induction of Carboxypeptidase A4 and Carboxypeptidase E in Hypoxic Human Adipose-Derived Stem Cells.

Hypoxia induces the expression of several genes through the activation of a master transcription factor, hypoxia-inducible factor (HIF)-1α. This study shows that hypoxia strongly induced the expression of two carboxypeptidases (CP), CPA4 and CPE, in an HIF-1α-dependent manner. The hypoxic induction of CPA4 and CPE gene was accompanied by the recruitment of HIF-1α and upregulation in the active histone modification, H3K4me3, at their promoter regions. The hypoxic responsiveness of CPA4 and CPE genes was observed in human adipocytes, human adipose-derived stem cells, and human primary fibroblasts but not mouse primary adipocyte progenitor cells. CPA4 and CPE have been identified as secreted exopeptidases that degrade and process other secreted proteins and matrix proteins. This finding suggests that hypoxia changes the microenvironment of the obese hypoxic adipose tissue by inducing the expression of not only adipokines but also peptidases such as CPA4 and CPE.

Loss of S6K1 But Not S6K2 in the Tumor Microenvironment Suppresses Tumor Growth by Attenuating Tumor Angiogenesis.

Two isoforms of the 70-kDa ribosomal protein S6 kinase, S6K1 and S6K2, have been identified and are considered key downstream effectors of the mTOR signaling pathway, which is involved in tumor growth and progression. However, their biological roles in the tumor microenvironment are poorly understood. In this study, utilizing tumor xenograft models in S6k1-/- and S6k2-/- mice, we show that loss of S6K1 but not S6K2 in the tumor stroma suppresses tumor growth, accompanied by attenuated tumor angiogenesis. We found that while S6K1 depletion had no effect on the proangiogenic phenotype of endothelial cells, the growth and angiogenesis of tumor xenografts were significantly reduced in wild-type mice upon reconstitution with S6K1-deficient bone marrow cells. Furthermore, upon S6K1 loss, induction of both mRNA and protein levels of Hif-1α and those of the downstream target, Vegf, was compromised in bone marrow-derived macrophages stimulated with lactate. These findings indicate that S6K1 but not S6K2 contributes to establishing a microenvironment that favors tumor growth through mediating angiogenesis, and suggest that attenuated tumor angiogenesis upon loss of S6K1 in the tumor stroma is, at least in part, attributable to impaired upregulation of Vegf in tumor-associated macrophages.

Bioactivity-based analysis and chemical characterization of cytotoxic constituents from Chaga mushroom (Inonotus obliquus) that induce apoptosis in human lung adenocarcinoma cells.

ETHNOPHARMACOLOGICAL RELEVANCE: Inonotus obliquus, also known as Chaga mushroom, is one of the most widely appreciated wild edible mushrooms in Russia and northern European countries and is renowned for its use in cancer treatment. Indeed, recently published in vitro and in vivo studies have demonstrated its anticancer activity in various types of cancer and support its potential application for therapeutic intervention in cancer. However, its activity against lung cancer, the most commonly diagnosed cancer and the leading cause of cancer death worldwide, and the underlying molecular basis of its action remain to be fully elucidated. OBJECTIVE: This study aimed to evaluate the cytotoxic activity of I. obliquus in four human lung adenocarcinoma cell lines with different p53 status (A549, H1264, H1299, and Calu-6) and identify its active constituents by bioactivity-based analysis and the underlying molecular basis of their cytotoxicity on lung cancer cells. MATERIALS AND METHODS: Bioactivity-guided fractionation and preparative/semi-preparative HPLC purification were used with LC/MS analysis to separate the bioactive constituents. Cell viability and apoptosis in human lung cancer cell lines (A549, H1264, H1299, and Calu-6) were assessed using the WST-1 assay and TUNEL staining, respectively. Caspase activation was assessed by detecting its surrogate markers, cleaved poly (ADP-ribose) polymerase (PARP) and caspase-3, using an immunoblot assay. RESULTS: The MeOH extract of I. obliquus reduced cell viability in all lung cancer cell lines tested through induction of apoptosis accompanied by caspase-3 cleavage. Bioactivity-guided fractionation of the MeOH extract and chemical investigation of its cytotoxic hexane-soluble and CH2Cl2-soluble fractions led to the isolation of eight triterpenoids (1-8), including a new lanostane-type triterpenoid named chagabusone A (7). The structures of the isolates were elucidated based on spectroscopic analysis, including 1D and 2D NMR and high-resolution ESIMS. Among isolated compounds, compounds 1, 6, and 7 showed the most potent cytotoxic activity in all human lung cancer cell lines examined, with IC50 values ranging from 75.1 to 227.4 µM. Cytotoxicity of these compounds was mediated by apoptosis with caspase-3 activation. CONCLUSION: These findings provide experimental evidence supporting the potential application of I. obliquus in lung cancer treatment and reveal the molecular basis underlying its cytotoxic activity against human lung cancer cells.

Bioactivity-guided isolation of ginsenosides from Korean Red Ginseng with cytotoxic activity against human lung adenocarcinoma cells.

BACKGROUND: Lung cancer is the leading cause of cancer-related death worldwide. In this study, we used a bioactivity-guided isolation technique to identify constituents of Korean Red Ginseng (KRG) with antiproliferative activity against human lung adenocarcinoma cells. METHODS: Bioactivity-guided fractionation and preparative/semipreparative HPLC purification were used with LC/MS analysis to separate the bioactive constituents. Cell viability and apoptosis in human lung cancer cell lines (A549, H1264, H1299, and Calu-6) after treatment with KRG extract fractions and constituents thereof were assessed using the water-soluble tetrazolium salt (WST-1) assay and terminal deoxyribonucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, respectively. Caspase activation was assessed by detecting its surrogate marker, cleaved poly adenosine diphosphate (ADP-ribose) polymerase, using an immunoblot assay. The expression and subcellular localization of apoptosis-inducing factor were assessed using immunoblotting and immunofluorescence, respectively. RESULTS AND CONCLUSION: Bioactivity-guided fractionation of the KRG extract revealed that its ethyl acetate-soluble fraction exerts significant cytotoxic activity against all human lung cancer cell lines tested by inducing apoptosis. Chemical investigation of the ethyl acetatesoluble fraction led to the isolation of six ginsenosides, including ginsenoside Rb1 (1), ginsenoside Rb2 (2), ginsenoside Rc (3), ginsenoside Rd (4), ginsenoside Rg1 (5), and ginsenoside Rg3 (6). Among the isolated ginsenosides, ginsenoside Rg3 exhibited the most cytotoxic activity against all human lung cancer cell lines examined, with IC50 values ranging from 161.1 µM to 264.6 µM. The cytotoxicity of ginsenoside Rg3 was found to be mediated by induction of apoptosis in a caspase-independent manner. These findings provide experimental evidence for a novel biological activity of ginsenoside Rg3 against human lung cancer cells.

Cytotoxic Constituents from the Sclerotia of Poria cocos against Human Lung Adenocarcinoma Cells by Inducing Mitochondrial Apoptosis.

Previous studies have revealed the antitumor potential of Poria cocos Wolf against a broad spectrum of cancers. However, the biological activity of P. cocos against lung cancer, which is known as the leading cause of cancer mortality worldwide, and its underlying chemical and molecular basis, remain to be investigated. We aimed to evaluate the in vitro cytotoxicity of P. cocos toward human lung adenocarcinoma cells with different p53 statuses, to identify the bioactive constituents of P. cocos, and explicate the molecular mechanisms underlying the cytotoxicity of these constituents in human lung adenocarcinoma cells. An EtOH extract of the sclerotia of P. cocos exhibited cytotoxicity toward four human lung cancer cell lines: A549, H1264, H1299, and Calu-6, regardless of their p53 status. Chemical investigation of the extract resulted in the isolation of two triterpenoids, dehydroeburicoic acid monoacetate (1) and acetyl eburicoic acid (4); a sterol, 9,11-dehydroergosterol peroxide (2); and a diterpenoid, dehydroabietic acid (3). All of the isolated compounds were cytotoxic to the lung adenocarcinoma cell lines, exhibiting IC50 values ranging from 63.6 µM to 171.0 µM at 48 h of treatment. The cytotoxicity of the extract and the isolated compounds were found to be mediated by apoptosis, and accompanied by elevated Bax expression and/or Bcl-2 phosphorylation along with caspase-3 activation. Our data demonstrate that the sclerotium of P. cocos and its four bioactive constituents (1⁻4) exert cytotoxicity against human lung adenocarcinoma cells, regardless of their p53 status, by inducing apoptosis associated with mitochondrial perturbation, and proposing the potential to employ P. cocos in the treatment of lung cancer.

Antiproliferative effect of Momordica cochinchinensis seeds on human lung cancer cells and isolation of the major constituents

Abstract Gac, Momordica cochinchinensis (Lour.) Spreng., Cucurbitaceae, is an indigenous South Asian edible fruit and has been used therapeutically in Traditional Chinese Medicine. Previous studies have shown that M. cochinchinensis seed (Momordicae Semen) has various pharmaceutical properties such as antioxidant and anti-ulcer effects as well as contains secondary metabolites with potential anticancer activities such as triterpenoids and saponins. However, its biological activities in cancer have not yet been investigated. In this study, we found that its ethanol extract reduced cell proliferation in four human lung cancer cell lines, A549, H1264, H1299 and Calu-6. Phytochemical investigation of the ethanol extract was carried out, and resulted in isolation of two major saponins, which were identified as gypsogenin 3-O-β-d-galactopyranosyl(1 → 2)-[α-l-rhamnopyranosyl(1 → 3)]-β-d-glucuronopyranoside (1) and quillaic acid 3-O-β-d-galactopyranosyl(1 → 2)-[α-l-rhamnopyranosyl(1 → 3)]-β-d-glucuronopyranoside (2). Treatment with these isolated compounds (1 and 2) decreased cel1 proliferation in all human lung cancer cell lines tested. In addition, the compounds attenuated primary lung endothelial cell proliferation. Taken together, these findings suggest M. cochinchinensis seeds have antiproliferative activity on human lung cancer cells as well as angiostatic effect on lung endothelial cells.