RESUMO
Multiple myeloma (MM) is a plasma cell malignancy without effective therapeutics. Thromboxane A2 (TxA2)/TxA2 receptor (T prostanoid receptor (TP)) modulates the progression of some carcinomas; however, its effects on MM cell proliferation remain unclear. In this study, we evaluated cyclooxygenase (COX) enzymes and downstream prostaglandin profiles in human myeloma cell lines RPMI-8226 and U-266 and analyzed the effects of COX-1/-2 inhibitors SC-560 and NS-398 on MM cell proliferation. Our observations implicate COX-2 as being involved in modulating cell proliferation. We further incubated MM cells with prostaglandin receptor antagonists or agonists and found that only the TP antagonist, SQ29548, suppressed MM cell proliferation. TP silencing and the TP agonist, U46619, further confirmed this finding. Moreover, SQ29548 and TP silencing promoted MM cell G2/M phase delay accompanied by reducing cyclin B1/cyclin-dependent kinase-1 (CDK1) mRNA and protein expression. Notably, cyclin B1 overexpression rescued MM cells from G2/M arrest. We also found that the TP agonist activated JNK and p38 MAPK phosphorylation, and inhibitors of JNK and p38 MAPK depressed U46619-induced proliferation and cyclin B1/CDK1 protein expression. In addition, SQ29548 and TP silencing led to the MM cell apoptotic rate increasing with improving caspase 3 activity. The knockdown of caspase 3 reversed the apoptotic rate. Taken together, our results suggest that TxA2/TP promotes MM cell proliferation by reducing cell delay at G2/M phase via elevating p38 MAPK/JNK-mediated cyclin B1/CDK1 expression and hindering cell apoptosis. The TP inhibitor has potential as a novel agent to target kinase cascades for MM therapy.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Fase G2/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Mieloma Múltiplo/tratamento farmacológico , Proteínas de Neoplasias/antagonistas & inibidores , Receptores de Tromboxano A2 e Prostaglandina H2/antagonistas & inibidores , Ácido 15-Hidroxi-11 alfa,9 alfa-(epoximetano)prosta-5,13-dienoico/farmacologia , Células da Medula Óssea/citologia , Compostos Bicíclicos Heterocíclicos com Pontes , Proteína Quinase CDC2 , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Ciclina B1/agonistas , Ciclina B1/antagonistas & inibidores , Ciclina B1/genética , Ciclina B1/metabolismo , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/química , Quinases Ciclina-Dependentes/genética , Quinases Ciclina-Dependentes/metabolismo , Inibidores de Ciclo-Oxigenase/farmacologia , Ácidos Graxos Insaturados , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Hidrazinas/farmacologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Mieloma Múltiplo/induzido quimicamente , Mieloma Múltiplo/metabolismo , Mieloma Múltiplo/patologia , Proteínas de Neoplasias/agonistas , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Interferência de RNA , Receptores de Tromboxano A2 e Prostaglandina H2/agonistas , Receptores de Tromboxano A2 e Prostaglandina H2/genética , Receptores de Tromboxano A2 e Prostaglandina H2/metabolismoRESUMO
Carnosine is an endogenous dipeptide with antiproliferative properties. Here we show that carnosine selectively inhibits proliferation of human glioblastoma cells (U-118-MG) compared to breast (MB231) and oral (Cal27 and FaDu) cancer cells. Carnosine-induced inhibition of U-118-MG proliferation is associated with a significant: decrease in cellular reactive oxygen species levels, increase in manganese superoxide dismutase (MnSOD) and increase in cyclin B1 expression resulting in G2-block. We conclude that the antiproliferative property of carnosine is due to its ability to enhance MnSOD and cyclin B1 expression. These results will be of significance to the potential application of carnosine in brain cancer therapy.
Assuntos
Antineoplásicos/farmacologia , Carnosina/farmacologia , Ciclina B1/genética , Neuroglia/efeitos dos fármacos , Espécies Reativas de Oxigênio/antagonistas & inibidores , Superóxido Dismutase/genética , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclina B1/agonistas , Ciclina B1/metabolismo , Relação Dose-Resposta a Droga , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neuroglia/metabolismo , Neuroglia/patologia , Especificidade de Órgãos , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismoRESUMO
Laryngeal squamous cell carcinoma is the most common form of head and neck squamous cell carcinoma. Multiple approaches have been applied to treat this type of cancer; however, no significant improvement in survival rate has been achieved. In the present study, the role of nemolike kinase (NLK) in human laryngeal carcinoma Hep2 cells was investigated. NLK has been identiï¬ed as an important regulator of cell growth, patterning and cell death in a variety of organisms. LentivirusmediatedshRNA was employed to silence endogenous NLK expression. Downregulation of the expression of NLK following lentivirus infection was confirmed using reverse transcription quantitative polymerase chain reaction and western blot analysis. The effects of NLK downregulation on Hep2 cell proliferation and cell cycle progression were analyzed using an MTT assay and flow cytometry, respectively. Downregulation of NLK also inhibited tumorigenesis and regulated the expression of cell cycle protein expression levels. Therefore, it was hypothesized that NLK is necessary for cell survival and tumorigenesis in laryngeal cancer cells. Furthermore, the absence of NLK may lead to cancer cell death. Collectively, the results of the present study demonstrated that the lentivirusmediated targeted disruption of NLK may be a promising therapeutic method for the treatment of laryngeal cancer.
Assuntos
Ciclina B1/agonistas , Ciclina D1/agonistas , Células Epiteliais/metabolismo , Regulação Neoplásica da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteína Supressora de Tumor p53/agonistas , Apoptose , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Ciclina B1/genética , Ciclina B1/metabolismo , Ciclina D1/genética , Ciclina D1/metabolismo , Células Epiteliais/patologia , Inativação Gênica , Vetores Genéticos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Laringe/metabolismo , Laringe/patologia , Lentivirus/genética , Fosforilação , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
Tubulin is an important target for anticancer therapy. Taxanes and vinca alkaloids are two groups of tubulin-binding agents in cancer chemotherapy. Besides tubulin binding, these groups of agents can also down-regulate protein levels of matrix metalloproteinase (MMP)-2 and -9, two important cancer-associated zinc-dependent endopeptidases in invasion and metastasis. However, the mechanism of action waits to be explored. In this study, protein levels but not mRNA expressions of MMP-2 and -9 were down-regulated by paclitaxel (a microtubule-stabilization agent), vincristine and evodiamine (two tubulin-depolymerization agents). These agents induced an increase of protein expression of cyclin B1, MPM2 (mitosis-specific phosphoprotein) and polo-like kinase (PLK) 1 phosphorylation. The data showed a negative relationship between the levels of mitotic proteins and MMP-2 and -9 expressions. MG132 (a specific cell-permeable proteasome inhibitor) blocked mitotic entry and arrested cell cycle at G2 phase, preventing down-regulation of MMP-2 and -9. Cell cycle synchronization experiments by thymidine block or nocodazole treatment showed that mitotic exit inhibited the down-regulation of MMP-2 and -9, confirming negative relationship between cell mitosis and protein levels of MMP-2 and -9 expressions. Cyclin-dependent kinase (Cdk) 1 is a key kinase in mitotic entry. Knockdown of Cdk1 almost completely inhibited the down-regulation of MMP-2 and -9 induced by tubulin-binding agents. In conclusion, the data suggest that mitotic entry and Cdk1 plays a central role in down-regulation of MMP-2 and -9 protein expressions. Tubulin-binding agents cause mitotic arrest and Cdk1 activation, which may contribute largely to the down-regulation of both MMP-2 and -9 expressions.
Assuntos
Antineoplásicos/farmacologia , Quinases Ciclina-Dependentes/genética , Regulação Neoplásica da Expressão Gênica , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 9 da Matriz/genética , Moduladores de Tubulina/farmacologia , Apoptose/efeitos dos fármacos , Proteína Quinase CDC2 , Proteínas de Ciclo Celular/agonistas , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Ciclina B1/agonistas , Ciclina B1/genética , Ciclina B1/metabolismo , Quinases Ciclina-Dependentes/antagonistas & inibidores , Quinases Ciclina-Dependentes/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/genética , Humanos , Leupeptinas/farmacologia , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Mitose/efeitos dos fármacos , Nocodazol/farmacologia , Paclitaxel/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Proto-Oncogênicas/agonistas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Quinazolinas/farmacologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Vincristina/farmacologia , Quinase 1 Polo-LikeRESUMO
In this study, we used branches Ramulus mori from cultivated mulberry Husang-32 (Morus multicaulis Perry) as the experimental material and anhydrous ethanol as the extraction solution to obtain the crude extract from the branch bark. The ethanolic extract was successively purified through a macroporous resin, Sephadex LH-20, and semipreparative reversed-phase high-performance liquid chromatography (RP-HPLC). The high-purity monomer was identified as morusin by HPLC with diode array detection (HPLC-DAD) and its UV spectrum. The contents of morusin exhibited almost no difference between the root and branch bark in Husang-32, and morusin was not detected in the leaves. Morusin is able to inhibit the tumor growth of transplanted H22 hepatocarcinoma in mice and has no side effects. The fluorescence quantitative real-time PCR (qRT-PCR) results indicate that morusin has a marked inhibitory effect on liver cancer cells through a mechanism that may be related increases in the expression of p53, Survivin, CyclinB1, and Caspase-3 and a decrease in NF-κ B gene expression. The influence of this compound is more apparent in the Caspase-3 and the NF-κ B genes.