RESUMO
Human biliary tree stem/progenitor cells (hBTSCs), reside in peribiliary glands, are mainly stimulated by primary sclerosing cholangitis (PSC) and cholangiocarcinoma. In these pathologies, hBTSCs displayed epithelial-to-mesenchymal transition (EMT), senescence characteristics, and impaired differentiation. Here, we investigated the effects of cholest-4,6-dien-3-one, an oxysterol involved in cholangiopathies, on hBTSCs biology. hBTSCs were isolated from donor organs, cultured in self-renewal control conditions, differentiated in mature cholangiocytes by specifically tailored medium, or exposed for 10 days to concentration of cholest-4,6-dien-3-one (0.14 mM). Viability, proliferation, senescence, EMT genes expression, telomerase activity, interleukin 6 (IL6) secretion, differentiation capacity, and HDAC6 gene expression were analyzed. Although the effect of cholest-4,6-dien-3-one was not detected on hBTSCs viability, we found a significant increase in cell proliferation, senescence, and IL6 secretion. Interestingly, cholest-4.6-dien-3-one impaired differentiation in mature cholangiocytes and, simultaneously, induced the EMT markers, significantly reduced the telomerase activity, and induced HDAC6 gene expression. Moreover, cholest-4,6-dien-3-one enhanced bone morphogenic protein 4 (Bmp-4) and sonic hedgehog (Shh) pathways in hBTSCs. The same pathways activated by human recombinant proteins induced the expression of EMT markers in hBTSCs. In conclusion, we demonstrated that chronic exposition of cholest-4,6-dien-3-one induced cell proliferation, EMT markers, and senescence in hBTSC, and also impaired the differentiation in mature cholangiocytes.
Assuntos
Sistema Biliar/citologia , Colestenonas/efeitos adversos , Desacetilase 6 de Histona/genética , Interleucina-6/genética , Sistema Biliar/efeitos dos fármacos , Sistema Biliar/metabolismo , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Senescência Celular , Transição Epitelial-Mesenquimal , Desacetilase 6 de Histona/metabolismo , Humanos , Interleucina-6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Células-Tronco/citologia , Células-Tronco/efeitos dos fármacos , Doadores de TecidosRESUMO
As a natural compound, Ornithogalum caudatum Ait is primarily used as an anti-inflammatory and antitumor agent in Chinese folk medicine. In 1992, OSW-1 was isolated from this compound, which is a new member of cholestane saponin family. In numerous recent studies, OSW-1 has been shown to have powerful cytotoxic anticancer effects against various malignant cells. However, the therapeutic efficacy of OSW-1 on colon cancer and the underlying mechanism are not understood. To explore the mechanism underlying OSW-1 in antitumor therapy, a therapeutic function analysis of OSW-1 on colon cancer was performed in vitro and in vivo. It was shown that with low toxicity on normal colonic cells, OSW-1 suppresses colon cancer cells in vitro and this inhibition was via the intrinsic apoptotic pathway, which increased cellular calcium, changed mitochondrial membrane potential, disrupted mitochondrial morphology, and led to the release of cytochrome c and the activation of caspase-3. Furthermore, in a nude mouse model, OSW-1 had a powerful effect on suppressing colon tumor proliferation without significant side effects through the apoptosis pathway. Taken together, these results demonstrate that OSW-1 is a potential drug for colon cancer treatment.
Assuntos
Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Colestenonas/administração & dosagem , Neoplasias do Colo/tratamento farmacológico , Saponinas/administração & dosagem , Animais , Caspase 3/genética , Linhagem Celular Tumoral , Colestenonas/efeitos adversos , Colestenonas/química , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , Citocromos c/genética , Citometria de Fluxo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Medicina Tradicional Chinesa , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Saponinas/efeitos adversos , Saponinas/química , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Phytosterol esters are phytosterols derived from vegetable oils following esterification to fatty acids. When phytosterols are added to foods, they inhibit the absorption of dietary and endogenous cholesterol and thereby reduce blood cholesterol concentrations. As part of a comprehensive programme of safety assessment, the mutagenic potential of phytosterols and phytosterol esters has been assessed in a bacterial mutation assay and an in vitro chromosome aberration assay. In addition, an in vitro mammalian cell gene mutation assay and two in vivo mutagenicity studies, namely rat bone marrow micronucleus and liver unscheduled DNA synthesis (UDS) assays, were conducted on phytosterol esters only. Phytosterols and phytosterol esters did not show any evidence of mutagenic activity in any of these assays. A breakdown product of cholesterol is 4-cholesten-3-one and thus the amount of 4-cholesten-3-one in the gut may increase following supplementation of foods with phytosterol-esters. 4-cholesten-3-one had been previously reported as mutagenic but, due to various shortcomings, these data could not be used to assess the mutagenic activity of 4-cholesten-3-one. The mutagenic activity of 4-cholesten-3-one and its major faecal by-products, 5beta-cholestan-3-one, was assessed in two in vitro assays, a bacterial mutation assay and an in vitro chromosome aberration assay. Neither 4-cholesten-3-one nor 5beta-cholestan-3-one showed evidence of mutagenic activity in these assays.