RESUMEN
BACKGROUND: Cervical cancer (CC) annually kills 288,000 women worldwide. Unfortunately, responses to chemoradiation are partial and are of short duration. As anti-EGFR monoclonal antibodies sensitise tumours, we investigated cetuximab's toxicity plus chemoradiation on CC cells, which express different EGFR levels. METHODS: EGFR, HER2, AKT and MAPK expression and phosphorylation status were determined by western blotting. Cytotoxicity was assessed by MTT or clonogenic assays (CA) in cell lines treated with cetuximab alone or in combinations. RESULTS: Cetuximab with cisplatin and radiation achieved maximum cytotoxic effects for A431, Caski and C33A cells (high, intermediate and low EGFR expression, respectively) in CA. Cetuximab efficiently decreased MAPK and AKT phosphorylation in A431 cells but slightly less in Caski and C33A cells. To check whether further EGFR, HER2 or MAPK inhibition would improve cetuximab's cytotoxicity, we combined it with an EGFR tyrosine kinase inhibitor (TKI), trastuzumab or a MEK1/2 inhibitor (PD98059). In Caski, but not in C33A cells, cetuximab cooperated with the TKI, reducing cell survival and AKT and MAPK phosphorylation. However, cetuximab with trastuzumab or PD98059 reduced survival and MAPK phosphorylation of both cell lines. CONCLUSION: Our data suggest that cetuximab combined with chemoradiation, trastuzumab or MAPK inhibitors has useful applications for CC treatment, independently of EGFR expression.
Asunto(s)
Anticuerpos Monoclonales/farmacología , Antineoplásicos/farmacología , Inhibidores Enzimáticos/farmacología , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/radioterapia , Anticuerpos Monoclonales Humanizados , Apoptosis/efectos de los fármacos , Apoptosis/efectos de la radiación , Ciclo Celular/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Cetuximab , Radioisótopos de Cobalto , Terapia Combinada , Receptores ErbB/antagonistas & inhibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Femenino , Humanos , Cinética , Proteínas Quinasas Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Fosforilación , ARN Mensajero/biosíntesis , ARN Mensajero/efectos de los fármacos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y Especificidad , Trastuzumab , Neoplasias del Cuello Uterino/patología , Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Factores de Crecimiento Endotelial Vascular/biosíntesis , Factores de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Cervical cancer is a public health problem and the molecular mechanisms underlying radioresistance are still poorly understood. Here, we evaluated the modulation of key molecules involved in cell proliferation, cell cycle and DNA repair in cervical cancer cell lines (CASKI and C33A) and in malignant tissues biopsied from 10 patients before and after radiotherapy. The expression patterns of epidermal growth factor receptor (EGFR), excision repair cross-complementation group 1 (ERCC1) and p53 were evaluated in cancer cell lines by quantitative PCR and western blotting, and in human malignant tissues by immunohistochemistry. The mutation status of TP53 gene was evaluated by direct sequencing. Among cell lines, absent or weak modulations of EGFR, ERCC1 and p53 were observed after exposure to 1.8 Gy. Conversely, increased expressions of p53 (5/10 patients; P=0.0239), ERCC1 (5/10 patients; P=0.0294) and EGFR (4/10 patients; P=0.1773) were observed in malignant tissues after radiotherapy with the same radiation dose. TP53 mutations were found only in one patient. Here we show that a single dose of radiotherapy induced EGFR, ERCC1 and p53 expression in malignant tissues from cervical cancer patients but not in cancer cell lines, highlighting the gap between in vitro and in vivo experimental models. Studies on larger patient cohorts are needed to allow an interpretation that an upregulation of p53, EGFR and ERCC1 may be part of a radioresistance mechanism.
Asunto(s)
Carcinoma de Células Escamosas/radioterapia , Proteínas de Unión al ADN/efectos de la radiación , Endonucleasas/efectos de la radiación , Genes erbB-1/efectos de la radiación , Genes p53/efectos de la radiación , Neoplasias del Cuello Uterino/radioterapia , Adulto , Anciano , Western Blotting , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/patología , Línea Celular Tumoral , Proliferación Celular/efectos de la radiación , Reparación del ADN/efectos de la radiación , Proteínas de Unión al ADN/metabolismo , Relación Dosis-Respuesta en la Radiación , Endonucleasas/metabolismo , Receptores ErbB/metabolismo , Femenino , Expresión Génica , Humanos , Inmunohistoquímica , Persona de Mediana Edad , Mutación , Estudios Prospectivos , Reacción en Cadena en Tiempo Real de la Polimerasa , Reproducibilidad de los Resultados , Resultado del Tratamiento , Ensayo de Tumor de Célula Madre , Proteína p53 Supresora de Tumor/metabolismo , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/patologíaRESUMEN
Cervical cancer is a public health problem and the molecular mechanisms underlying radioresistance are still poorly understood. Here, we evaluated the modulation of key molecules involved in cell proliferation, cell cycle and DNA repair in cervical cancer cell lines (CASKI and C33A) and in malignant tissues biopsied from 10 patients before and after radiotherapy. The expression patterns of epidermal growth factor receptor (EGFR), excision repair cross-complementation group 1 (ERCC1) and p53 were evaluated in cancer cell lines by quantitative PCR and western blotting, and in human malignant tissues by immunohistochemistry. The mutation status of TP53 gene was evaluated by direct sequencing. Among cell lines, absent or weak modulations of EGFR, ERCC1 and p53 were observed after exposure to 1.8 Gy. Conversely, increased expressions of p53 (5/10 patients; P=0.0239), ERCC1 (5/10 patients; P=0.0294) and EGFR (4/10 patients; P=0.1773) were observed in malignant tissues after radiotherapy with the same radiation dose. TP53 mutations were found only in one patient. Here we show that a single dose of radiotherapy induced EGFR, ERCC1 and p53 expression in malignant tissues from cervical cancer patients but not in cancer cell lines, highlighting the gap between in vitro and in vivo experimental models. Studies on larger patient cohorts are needed to allow an interpretation that an upregulation of p53, EGFR and ERCC1 may be part of a radioresistance mechanism.