RESUMO
Background: The poor outcome of advanced renal cell carcinoma (RCC) necessitates new treatments. Cobimetinib is a MEK inhibitor and approved for the treatment of melanoma. This work investigated the efficacy of cobimetinib alone and in combination with anti-RCC drugs. Methods: Proliferation and apoptosis assays were performed, and combination index was analyzed on RCC cell lines (CaKi-2, 786-O, A-704, ACHN and A489) and xenograft models. Immunoblotting analysis was conducted to investigate the MAPK pathway. Results: Cobimetinib was active against RCC cells, with IC50 at 0.006-0.8µM, and acted synergistically with standard-of-care therapy. Cobimetinib at nontoxic doses prevented tumor formation, inhibited tumor growth and enhanced efficacy of 5-fluorouracil, sorafenib and sunitinib via suppressing Raf/MEK/ERK, leading to MAPK pathway inhibition. Conclusion: Our findings demonstrate the potent anti-RCC activity of cobimetinib and its synergism with RCC standard-of-care drugs, and confirm the underlying mechanism of the action of cobimetinib.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Azetidinas/farmacologia , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Piperidinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Azetidinas/uso terapêutico , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sinergismo Farmacológico , Fluoruracila/farmacologia , Fluoruracila/uso terapêutico , Humanos , Neoplasias Renais/patologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Masculino , Camundongos , Piperidinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Sunitinibe/farmacologia , Sunitinibe/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Fucoidan is a sulfated polysaccharide that is extracted from brown algae seaweed. This study was designed to evaluate the protective and immunomodulatory effects of dietary fucoidan on 7,12-dimethyl benz[a]anthracene (DMBA)-induced experimental mammary carcinogenesis in rats. Sixty Sprague-Dawley rats were randomly assigned to four equal groups: the control group (control group), the cancer model group (model group), and the F1 and F2 groups, which were fed fucoidan at concentrations of 200 and 400 mg/kg·body weight, respectively. We found that fucoidan treatment decreased the tumor incidence and mean tumor weight and prolonged the tumor latency. Flow cytometric analyses revealed that the number of blood natural killer cells was higher after fucoidan treatment and that the proportions of CD4 and CD8 T cells were also increased. The serum levels of interleukin (IL)-6, IL-12p40, and interferon (IFN)-γ were higher in the rats treated with fucoidan compared to those of model rats. Moreover, the percentage of CD3+ Foxp3+ regulatory T cells in the blood and the levels of IL-10 and transforming growth factor ß in the serum were lower in the rats treated with fucoidan. Furthermore, fucoidan treatment decreased the expression of Foxp3 and programmed cell death 1 ligand 1 (PDL1) in tumor tissues. The levels of p-phosphatidyl inositol kinase 3 and p-AKT in tumor tissues were also lower than those of model rats. These results suggest that a fucoidan-supplemented diet can inhibit DMBA-induced tumors in rats. This study provides experimental evidence toward elucidating the immune enhancement induced by fucoidan through the programmed cell death 1/PDL1 signaling pathway. The immunomodulatory effect is one of the possible mechanisms of the protective effect of fucoidan against mammary carcinogenesis.