Proteomics profiling of cholangiocarcinoma exosomes: A potential role of oncogenic protein transferring in cancer progression

AbstractCholangiocarcinoma (CCA), a common primary malignant tumor of bile duct epithelia, is highly prevalent in Asian countries and unresponsive to chemotherapeutic drugs. Thus, a newly recognized biological entity for early diagnosis and treatment is highly needed. Exosomes are small membrane bound vesicles found in body fluids and released by most cell types including cancer cells. The vesicles contain specific subset of proteins and nucleic acids corresponding to cell types and play essential roles in pathophysiological processes. The present study aimed to assess the protein profiles of CCA-derived exosomes and their potential roles. We have isolated exosomes from CCA cells namely KKU-M213 and KKU-100 derived from Thai patients and their roles were investigated by incubation with normal human cholangiocyte (H69) cells. Exosomes were internalized into H69 cells and had no effects on viability or proliferation of the host cells. Interestingly, the exosomes from KKU-M213 cells only induced migration and invasion of H69 cells. Proteomic analysis of the exosomes from KKU-M213 cells disclosed multiple cancer related proteins that are not present in H69 exosomes. Consistent with the protein profile, treatment with KKU-M213 exosomes induced β-catenin and reduced E-cadherin expressions in H69 cells. Collectively, our results suggest that a direct cell-to-cell transfer of oncogenic proteins via exosomal pathway may be a novel mechanism for CCA progression and metastasis

Human chorion-derived mesenchymal stem cells suppress JAK2/STAT3 signaling and induce apoptosis of cholangiocarcinoma cell lines

Cholangiocarcinoma (CCA) is an aggressive malignancy arising from the damaged epithelial cells of the biliary tract. Previous studies have reported that the multi-potent mesenchymal stem cells (MSCs) activate a series of tumor signaling pathways by releasing several cytokines to influence tumor cell development. However, the roles and mechanisms of human chorion-derived MSCs (CH-MSCs) in cholangiocarcinoma progression have not been fully addressed. This present study aims to examine the effects of conditioned media derived from CH-MSCs (CH-CM) on CCA cell lines and investigate the respective underlying mechanism of action. For this purpose, MSCs were isolated from chorion tissue, and three cholangiocarcinoma cell lines, namely KKU100, KKU213A, and KKU213B, were used. MTT assay, annexin V/PI analysis, and JC-1 staining were used to assess the effects of CH-CM on proliferation and apoptosis of CCA cells, respectively. Moreover, the effect of CH-CM on caspase-dependent apoptotic pathways was also evaluated. The western blotting assay was also used for measuring the expression of JAK2/STAT3 signaling pathway-associated proteins. The results showed that CH-CM suppressed proliferation and promoted apoptosis of CCA cell lines. CH-CM treatment-induced loss of mitochondrial membrane potential (∆Ψm) in CCA cell lines. The factors presented in the CH-CM also inhibited JAK2/STAT3 signaling, reduced the expression of BCL-2, and increased BAX expression in CCA cells. In conclusion, our study suggests that the CH-CM has a potent anti-cancer effect on cholangiocarcinoma cells and thus provides opportunities for use in alternative cell therapy or in combination with a conventional chemotherapeutic drug to increase the efficiency of CCA treatment

Polyketides From the Endophytic Fungus Cladosporium sp. Isolated From the Mangrove Plant Excoecaria agallocha

Five new polyketides (2–6) and ten known compounds (1 and 7–15) were obtained from the fermentation products of the endophytic fungus Cladosporium sp. OUCMDZ-302 with the mangrove plant, Excoecaria agallocha (Euphorbiaceae). The new structures of 2–6 were established on the basis of ECD, specific rotation and spectroscopic data as well as the chemical calculation. Compound 7 showed cytotoxicity against H1975 cell line with an IC50 value of 10.0 μM. Compounds 4 and 8–10 showed radical scavenging activity against DPPH with the IC50 values of 2.65, 0.24, 5.66, and 6.67 μM, respectively. In addition, the absolute configuration of compound 1 was solidly determined by X-ray and sugar analysis of the acidic hydrolysates for the first time as well as those of compounds 8–10 in this paper

Antigen-specific, antibody-coated, exosome-like nanovesicles deliver suppressor T-cell microRNA-150 to effector T cells to inhibit contact sensitivity

Background: T-cell tolerance of allergic cutaneous contact sensitivity (CS) induced in mice by high doses of reactive hapten is mediated by suppressor cells that release antigen-specific suppressive nanovesicles. Objective: We sought to determine the mechanism or mechanisms of immune suppression mediated by the nanovesicles. Methods: T-cell tolerance was induced by means of intravenous injection of hapten conjugated to self-antigens of syngeneic erythrocytes and subsequent contact immunization with the same hapten. Lymph node and spleen cells from tolerized or control donors were harvested and cultured to produce a supernatant containing suppressive nanovesicles that were isolated from the tolerized mice for testing in active and adoptive cell-transfer models of CS. Results: Tolerance was shown due to exosome-like nanovesicles in the supernatants of CD81 suppressor T cells that were not regulatory T cells. Antigen specificity of the suppressive nanovesicles was conferred by a surface coat of antibody light chains or possibly whole antibody, allowing targeted delivery of selected inhibitory microRNA (miRNA)–150 to CS effector T cells. Nanovesicles also inhibited CS in actively sensitized mice after systemic injection at the peak of the responses. The role of antibody and miRNA-150 was established by tolerizing either panimmunoglobulin-deficient JH2/2 or miRNA-1502/2 mice that produced nonsuppressive nanovesicles. These nanovesicles could be made suppressive by adding antigen-specific antibody light chains or miRNA-150, respectively. Conclusions: This is the first example of T-cell regulation through systemic transit of exosome-like nanovesicles delivering a chosen inhibitory miRNA to target effector T cells in an antigen-specific manner by a surface coating of antibody light chains

Exosome release of β-catenin: a novel mechanism that antagonizes Wnt signaling

The tetraspanins CD9 and CD82 suppress Wnt signaling by promoting the discharge of β-catenin from cells

Precursor-Directed Generation of Indolocarbazoles with Topoisomerase IIα Inhibitory Activity

One new indolocarbazole, 3-hydroxy-K252d (3), together with the recently reported 3-hydroxyholyrine A (1) and 3′-N-acetyl-3-hydroxyholyrine A (2), were obtained by feeding a culture of the marine-derived Streptomyces strain OUCMDZ-3118 with 5-hydroxy-l-tryptophan. Their structures were elucidated on the basis of spectroscopic analysis. Compound 1 potently induced apoptosis of gastric cancer cells by inhibiting topoisomerase IIα enzyme activity and reducing the expression of antiapoptosis protein level. Compound 3 displayed moderate cytotoxicity against the A549 and MCF-7 cell lines with IC50 values of 1.2 ± 0.05 μM, 1.6 ± 0.09 μM, respectively

New Ansamycins from the Deep-Sea-Derived Bacterium Ochrobactrum sp. OUCMDZ-2164

Two new ansamycins, trienomycins H (1) and I (2), together with the known trienomycinol (3), were isolated from the fermentation broth of the deep-sea-derived bacterium Ochrobactrum sp. OUCMDZ-2164. Their structures, including their absolute configurations, were elucidated based on spectroscopic analyses, ECD spectra, and Marfey’s method. Compound 1 exhibited cytotoxic effects on A549 and K562 cell lines with IC50 values of 15 and 23 μM, respectively

Bone sparing effect of a novel phytoestrogen diarylheptanoid from Curcuma comosa Roxb. in ovariectomized rats.

Phytoestrogens have been implicated in the prevention of bone loss in postmenopausal osteoporosis. Recently, an active phytoestrogen from Curcuma comosa Roxb, diarylheptanoid (DPHD), (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol, was found to strongly promote human osteoblast function in vitro. In the present study, we demonstrated the protective effect of DPHD on ovariectomy-induced bone loss (OVX) in adult female Sprague-Dawley rats with 17β-estradiol (E2, 10 µg/kg Bw) as a positive control. Treatment of OVX animals with DPHD at 25, 50, and 100 mg/kg Bw for 12 weeks markedly increased bone mineral density (BMD) of tibial metaphysis as measured by peripheral Quantitative Computed Tomography (pQCT). Histomorphometric analysis of bone structure indicated that DPHD treatment retarded the ovariectomy-induced deterioration of bone microstructure. Ovariectomy resulted in a marked decrease in trabecular bone volume, number and thickness and these changes were inhibited by DPHD treatment, similar to that seen with E2. Moreover, DPHD decreased markers of bone turnover, including osteocalcin and tartrate resistant acid phosphatase (TRAP) activity. These results suggest that DPHD has a bone sparing effect in ovariectomy-induced trabecular bone loss and prevents deterioration of bone microarchitecture by suppressing the rate of bone turnover. Therefore, DPHD appears to be a promising candidate for preserving bone mass and structure in the estrogen deficient women with a potential role in reducing postmenopausal osteoporosis