RESUMO
We examined extracellular signalregulated kinase (ERK), 4Ebinding protein 1 (4EBP1) and p70 ribosomal S6 kinase (p70) as potential biomarkers for pretreatment prediction of the prognosis of patients with metastatic renal cell carcinoma (RCC) treated with sorafenib, sunitinib or everolimus. 786O and 769P cells were treated with sorafenib, sunitinib and everolimus. The expression of phosphorylated/total ERK, phosphorylated/total 4EBP1 and phosphorylated/total p70 was evaluated using western blotting. ERK, 4EBP1 and p70 were knocked down by siRNA in 786O and 769P cells. Then, the viability after treatment with each drug was assessed. Expression of phosphorylated (phospho)ERK, -4EBP1 and -p70 was immunohistochemically evaluated in radical nephrectomy specimens and correlated with progressionfree survival during treatment with each molecular targeting agent. Sorafenib inhibited the expression of phospho-ERK and -4EBP1 in 769P cells; sunitinib, phospho-ERK and -4EBP1 in 786O and 769P cells; and everolimus, phospho-p70 in 786O and 769P cells. Knockdown of ERK reduced sensitivity to sorafenib in both cell lines, knockdown of ERK and 4EBP1 reduced sensitivity to sunitinib in 769P cells, and knockdown of 4EBP1 and p70 reduced sensitivity to everolimus in 786O cells. High expression of phospho-ERK, -4EBP1 and -p70 correlated with better progressionfree survival in patients treated with sorafenib, sunitinib and everolimus, respectively. Our results indicate that phospho-ERK, -4EBP1 and/or -ERK, and phospho-p70 can be used as biomarkers for the therapeutic efficacy of sorafenib, sunitinib and everolimus, respectively.
Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Everolimo/farmacologia , Indóis/farmacologia , Niacinamida/análogos & derivados , Compostos de Fenilureia/farmacologia , Pirróis/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adulto , Idoso , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/mortalidade , Proteínas de Ciclo Celular , Linhagem Celular Tumoral , Intervalo Livre de Doença , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/metabolismo , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Niacinamida/farmacologia , Fosfoproteínas/genética , Fosfoproteínas/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Sorafenibe , Sunitinibe , Resultado do TratamentoRESUMO
BACKGROUND: COX-2 inhibitors have an antitumor potential and have been verified by many researchers. Treatment of cancer cells with external stressors such as irradiation can stimulate the over-expression of COX-2 and possibly confer radiation resistance. In this study, we tested if topical diclofenac, which inhibits both COX-1 and COX-2, administration rendered prostate tumor cells sensitize to the effects of radiation. METHODS: LNCaP-COX-2 and LNCaP-Neo cells were treated with 0 to 1000 µM diclofenac. Next, a clonogenic assay was performed in which cells were subjected to irradiation (0 to 4 Gy) with or without diclofenac. COX-2 expression and other relevant molecules were measured by real-time PCR and immunohistochemistry after irradiation and diclofenac treatment. In addition, we assessed the tumor volumes of xenograft LNCaP-COX-2 cells treated with topical diclofenac with or without radiation therapy (RT). RESULTS: LNCaP-COX-2 and LNCaP-Neo cell lines experienced cytotoxic effects of diclofenac in a dose related manner. Clonogenic assays demonstrated that LNCaP-COX-2 cells were significantly more resistant to RT than LNCaP-Neo cells. Furthermore, the addition of diclofenac sensitized LNCaP-COX-2 not but LNCaP-Neo cells to the cytocidal effects of radiation. In LNCaP-COX-2 cells, diclofenac enhanced radiation-induced apoptosis compared with RT alone. This phenomenon might be attributed to enhancement of RT-induced TRAIL expression as demonstrated by real-time PCR analysis. Lastly, tumor volumes of LNCaP-COX-2 cells xenograft treated with diclofenac or RT alone was >4-fold higher than in mice treated with combined diclofenac and radiation (p<0.05). CONCLUSIONS: These in vitro and in vivo findings suggest that conventional COX inhibitor, diclofenac enhances the effect of RT on prostate cancer cells that express COX-2. Thus, diclofenac may have potential as radiosensitizer for treatment of prostate cancer.