RESUMO
Bisphenol A (BPA) and 4-cumylphenol (4-CP), as estrogen-like chemicals, are ubiquitous in the environment media and associated with the occurrence and development of hormone-dependent tumors. However, the combinatorial effects of these two structurally similar alkylphenols are not well informed. In the present study, the classic breast cancer cell line MCF-7 was used as in vitro model to estimate the estrogenic proliferative effects of BPA and 4-CP. MTT assay, reactive oxygen species, cell apoptosis, cell cycle, and real-time fluorescent quantitative Step One Plus Real-time PCR System (Applied Biosystems, CA, USA) were applied to explore their proliferative mechanisms. MTT results showed that both BPA and 4-CP ranging from 10-9 to 10-5 M stimulated cell proliferation in a nonmonotonic dose-response manner. Along with the proliferative effects, cell cycle was progressed from G0/G1 to S and G2/M phase. Meanwhile, the expression levels of ERα, pS2, and Bcl-2 mRNA were also upregulated. In contrast, 4-CP and BPA at high dose (10-4 M) obviously displayed antiproliferative effects in MCF-7 cells via inducing cell apoptosis and blocking cell cycle in G0/G1 phase. As expected, the relative expression levels of ERα, pS2, and Bcl-2 mRNA were decreased, whereas Bax mRNA was increased. Interestingly, the proliferative or antiproliferative effects of 4-CP were higher than that of BPA. Moreover, coexposure of lower concentrations BPA and 4-CP significantly induced cell proliferation in a synergistic manner. These findings indicated that the potential environmental risks of coexposure of BPA and 4-CP were greater than either of them.
Assuntos
Compostos Benzidrílicos/toxicidade , Neoplasias da Mama/patologia , Proliferação de Células/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Estrogênios/metabolismo , Fenóis/toxicidade , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Ciclo Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Células MCF-7 , Proteínas Proto-Oncogênicas c-bcl-2/metabolismoRESUMO
The environmental ecological risks of dissolved organic matter (DOM) extracted from diverse sewage treatment plants and processes have attracted urgent attention. The correlations between the toxicity of DOM and its compositions or properties deserved to be explored to evaluate the environmental risk. Human liver cancer (HepG2) and normal liver (L02) cell lines were used in in vitro experiments evaluating the environmental risks of dissolved organics discharged from secondary and advanced sewage treatment processes. Organics extracted from dewatered sludge were also tested. Elemental compositions were determined and optical characterization was performed. The results indicated that the organics in the effluent from anaerobic-anoxic-oxic processes contained more oxygen-containing groups and hydrophilic substances than those in other types of effluent. The sludge extracts showed the greatest cytotoxicity, followed by the effluent from secondary treatment and then the effluent from an advanced treatment process. The sludge extracts inhibited cell proliferation while the other effluents promoted it at a 5 mgC/L concentration. The organics discharged from secondary and advanced treatment processes induced relatively little production of reactive oxygen species. That stimulated cell self-repair and free radical scavenging and consequently resulted in cell proliferation with the cell lines tested. Oxygen-containing groups in the dissolved organics promoted cell proliferation and ROS removal. The atomic ratios and UV spectroscopy indices contributed mainly to the cell viability among the positive indicators. These results provide theoretical basis for managing the ecological risks posed by dissolved organics released from sewage treatment processes.
Assuntos
Esgotos , Eliminação de Resíduos Líquidos , OxigênioRESUMO
Tamoxifen has been applied widely in the treatment of estrogen receptor (ER)-positive breast cancer. The impact of low concentrations of 17ß-estradiol (E2) (a pervasive environmental pollutant) on its effectiveness was studied in vitro using an MCF-7â¯cell line. Cell proliferation, migration, invasion, and apoptosis were studied along with cell cycle progression, reactive oxygen species generation and mitochondrial membrane potentials repression. The signaling pathways involved were identified. Typical concentrations of E2 in the environment (10-10 to 10-8â¯M) were observed to promote cell growth and protect MCF-7â¯cells from tamoxifen's cytotoxicity. Cell migration, invasion, cell cycle progression and apoptosis all involved in reducing tamoxifen's cytotoxicity. E2 at environmental concentrations induced PI3K/Akt and MAPK/ERK signal transduction through the estrogen receptor pathways to affect cell proliferation. Taken together, the results explain how E2 in the environment may attenuate the efficacy of tamoxifen in ER-positive breast cancer therapy. They provide considerable support for E2's adverse effects on human health and cancer management.
Assuntos
Neoplasias da Mama/metabolismo , Estradiol/toxicidade , Tamoxifeno/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Divisão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Fosfatidilinositol 3-Quinases/metabolismo , Receptores de Estrogênio/metabolismo , Transdução de Sinais/efeitos dos fármacosRESUMO
Selective estrogen receptor modulators such as tamoxifen (TAM) significantly reduce the risks of developing estrogen receptor-positive (ER+) breast cancer. Low concentrations (nanomolar range) of bisphenol A (BPA) shows estrogenic effects and further promotes the proliferation of hormone-dependent breast cancer cells. However, whether or not BPA can influence TAM-treatment resistance in breast cancer has not drawn much attention. In the current study, low concentrations of BPA reduced TAM-induced cytotoxicity of MCF-7 cells, which was proved by the suppression of cell apoptosis, transition of cell cycle from G1 to S phase, and upregulation of cyclin D1 and ERα. Simultaneously, the mRNA levels of estrogen-related receptor γ (ERRγ) and its coactivators, peroxisome proliferation-activated receptor γ coactivator-1α (PGC-1α), and PGC-1ß, were increased. However, the similar effects were not observed in MDA-MB-231 cells. Our results indicated that low concentrations of BPA decreased the sensitivity of TAM in MCF-7 cells rather than in MDA-MB-231 cells. These different actions likely involved the interaction of relative receptors and coactivators. This study provided a possible support that the exposure of BPA in environmental media may potentially induce TAM resistance to breast cancer treatment.
Assuntos
Apoptose/efeitos dos fármacos , Compostos Benzidrílicos/toxicidade , Neoplasias da Mama/tratamento farmacológico , Fenóis/toxicidade , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Compostos Benzidrílicos/administração & dosagem , Neoplasias da Mama/induzido quimicamente , Neoplasias da Mama/patologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclina D1/genética , Relação Dose-Resposta a Droga , Receptor alfa de Estrogênio/genética , Estrogênios/toxicidade , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Células MCF-7 , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Fenóis/administração & dosagem , Fator Trefoil-1/genéticaRESUMO
Dissolved organic matter (DOM) can act as an electron shuttle in biogeochemical redox reactions to affect the fate of contaminants. Herein DOMs were tested for their ability to mediate in the degradation of 17α-ethinylestradiol (EE2) in a coupled electrochemical and biological system. Fulvic acid (FA) and Sigma humic acid (SHA) were found to promote degradation by the electro-domesticated micro-organisms in the coupled system. Analyses of superoxide dismutase levels, microbial community and clusters of orthologous groups of proteins showed that electrical stimulation promoted their growth and metabolism. It was confirmed that electron transfer in the coupled system was promoted in the presence of DOM as their protein-like components were converted into aromatic substances. The electrical stimulation improved the microorganisms' effectiveness in subsequent biodegradation under anaerobic condition. Stimulated micro-organisms seemed to increase their environmental tolerance and degrade EE2 effectively. These findings provide evidence about the fate of estrogens in bioelectrochemical water treatment.
Assuntos
Etinilestradiol , Poluentes Químicos da Água , Anaerobiose , Biodegradação Ambiental , Substâncias HúmicasRESUMO
Breast cancer is the most diagnosed diseases and the second-leading cause of death in females, among which the estrogen receptor positive (ER+) patients are more common of all cases. In present study, we selected MCF-7 as an in vitro model and investigated the combinatorial anti-proliferative effects of tamoxifen and naringenin on ER+ breast cancer, and then explored the potential mechanisms involved in mitochondrial dysfunction and oxidative stress mediated by several estrogen receptor subtypes. Six assessment endpoints including cell viability, cell migration, cell cycle, cell apoptosis, mRNA, and protein expression were estimated. Tamoxifen and naringenin were shown to inhibit the cell growth of MCF-7 cells at higher concentrations, and co-exposure with them significantly inhibited cell proliferation in an additive manner. Results from a wound healing assay indicated that the combined treatment of tamoxifen and naringenin markedly suppressed cell migration compared with the single exposure by downregulating the expression of MMP-9 and MMP-2. Flow cytometry analysis revealed that the combined treatment of tamoxifen and naringenin blocked cell cycle in G2/M phase through suppressing the transcription of cell cycle regulation proteins. Simultaneously, co-treatment with them also induced cell apoptosis by regulating the expression of mitochondrial apoptotic proteins as well as by simulating the production of reactive oxygen species (ROS). Real-time quantitative polymerase chain reaction (RT-qPCR) and western blotting (WB) analysis results further demonstrated that the two nuclear estrogen receptors-ERα66 and ERß, as well as the two membrane estrogen receptors-ERα36 and GPR30 were downregulated when cells were exposed to single tamoxifen, whereas naringenin treatment group not only downregulated the expression of ERα66 and GPR30 but also upregulated ERß and ERα36. Interestingly, co-treatment group resulted in significant downregulation of ERα66, ERα36 and GPR30 but upregulation of ERß. Taken together, co-treatment of tamoxifen and naringenin could inhibit cell proliferation more effectively in ER+ breast cancer cells, which was associated with a modulation of the expression levels of several estrogen receptors.