RESUMEN
BACKGROUND: The aim of this study was to evaluate the radiosensitising effect of gemcitabine, in terms of cell-cycle progression, induction of apoptosis, and to investigate the molecular events regulating apoptosis. METHODS: Tumour cells were treated with gemcitabine, radiation, or the combination. 0-72 h after treatment, cells were collected for cell-cycle analysis and apoptosis determination. Caspase 8 and 9, Bid and tBid expression were determined by western blot. The mitochondrial membrane potential was determined using flow cytometry. An RT(2) Profiler PCR Array for human apoptotic genes was performed after the combination or TRAIL treatment. RESULTS: Gemcitabine and radiation resulted in an early S-phase block immediately after treatment, after which the cells moved synchronously through the cell cycle. When cell-cycle distribution returned to pre-treatment levels, an increased induction of apoptosis was observed with activation of caspase 8 and 9 and a reduction of the mitochondrial membrane potential. Gene expression after treatment with radiosensitising conditions was comparable with expression after the TRAIL treatment. CONCLUSION: A role for the cell-cycle perturbations and the induction of apoptosis could be attributed to the radiosensitising effect of gemcitabine. Apoptosis induction was comparable with the apoptotic pathway observed after the TRAIL treatment, that is the involvement of the extrinsic apoptosis pathway.
Asunto(s)
Apoptosis/efectos de los fármacos , Desoxicitidina/análogos & derivados , Fármacos Sensibilizantes a Radiaciones/farmacología , Apoptosis/fisiología , Apoptosis/efectos de la radiación , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/efectos de los fármacos , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/metabolismo , Proteína Proapoptótica que Interacciona Mediante Dominios BH3/efectos de la radiación , Western Blotting , Caspasa 8/efectos de los fármacos , Caspasa 8/metabolismo , Caspasa 8/efectos de la radiación , Caspasa 9/efectos de los fármacos , Caspasa 9/metabolismo , Caspasa 9/efectos de la radiación , Línea Celular Tumoral , Desoxicitidina/farmacología , Activación Enzimática/efectos de los fármacos , Activación Enzimática/efectos de la radiación , Citometría de Flujo , Humanos , Etiquetado Corte-Fin in Situ , Potencial de la Membrana Mitocondrial , Reacción en Cadena de la Polimerasa , GemcitabinaRESUMEN
Vaginal self-sampling may be valuable as an alternative method of cervical cancer screening in areas of poor resources, to enroll women who, otherwise, would not participate in population-based cervical cancer screening and in epidemiological follow-up studies. We assessed the reliability of mailed vaginal samples by evaluating the quantity and quality of genomic DNA in the samples. Mailed swabs (n = 201) were compared with freshly collected samples (n = 200) for DNA concentration (45.1 versus 50.9 ng/microl, respectively) and purity (mean optical density [OD] 260/280 ratio 1.88 versus 1.78, respectively). A small, non-significant, decrease in DNA yield with longer transport time was noted. The DNA yield of mailed samples was significantly lower compared to fresh samples (P < 0.002), but this lower yield had little effect on polymerase chain reaction (PCR) amplification. In conclusion, the large majority of mailed self-sampled vaginal swabs resulted in DNA of adequate purity and concentration for further research.
Asunto(s)
ADN Viral/aislamiento & purificación , Tamizaje Masivo/métodos , Servicios Postales , Autoexamen/métodos , Manejo de Especímenes/métodos , Vagina/virología , Adolescente , Bélgica , Estudios de Evaluación como Asunto , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Humanos , Infecciones por Papillomavirus/diagnóstico , Infecciones por Papillomavirus/virología , Reacción en Cadena de la Polimerasa , Adulto JovenRESUMEN
Ecteinascidin 743 (ET-743) is a new marine-derived agent with promising activity against a number of solid tumours. In four human tumour cell lines, the interaction between ET-743 and radiation was investigated in relation to the effects of ET-743 on the cell cycle, in vitro. Cell survival was measured based on quantitative staining of cellular protein by sulforhodamine B. A 24 h treatment with ET-743 before radiation resulted in a moderate increase in radiosensitivity in three out of four cell lines. Dose enhancement factors > or =1.8 were observed for concentrations resulting in 52, 46 and 30% cell kill in ECV304, H292 and CAL-27, respectively, whereas in A549 no radiosensitisation was observed (no significant increase in radiosensitivity). According to the combination index analysis, synergism was observed only in ECV304 and CAL-27 cells. A 24 h incubation with ET-743 resulted in a concentration-dependent G2/M block, which might explain the moderate radiosensitising effects in ECV304 and H292. The lack of radiosensitisation in A549 might be due to the S phase delay preceding the G2/M block at the moment of radiation, which only occurred in this cell line. In conclusion, ET-743 has moderate cell line-dependent radiosensitising properties; however, only when cytotoxic concentrations of ET-743 are used. In one of the four cell lines tested, no radiosensitisation was observed.
Asunto(s)
Antineoplásicos Alquilantes/farmacología , Carcinoma/terapia , Ciclo Celular/efectos de los fármacos , Dioxoles/farmacología , Isoquinolinas/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Carcinoma/tratamiento farmacológico , Carcinoma/radioterapia , Ciclo Celular/efectos de la radiación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/efectos de la radiación , Terapia Combinada , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/radioterapia , Neoplasias Pulmonares/terapia , Tetrahidroisoquinolinas , Neoplasias de la Lengua/tratamiento farmacológico , Neoplasias de la Lengua/radioterapia , Neoplasias de la Lengua/terapia , Trabectedina , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Neoplasias de la Vejiga Urinaria/radioterapia , Neoplasias de la Vejiga Urinaria/terapiaRESUMEN
In this study, the radiosensitising effect of different concentrations of gemcitabine and the combination of gemcitabine/radiotherapy with the rescue agent amifostine was investigated in different human tumour cell lines. The cells were treated with gemcitabine (0-8 nM) for 24 h prior to radiation (0-8 Gy). Amifostine (ami) and alkaline phosphatase (AP) were added 30 min before radiation. Cell survival was determined 7 or 8 days after radiation treatment by the sulforhodamine B (SRB) test. For ECV304 cells, the dose enhancement factor (DEF) varied from 1.39 to 2.98 after treatment with 1-6 nM gemcitabine. FaDu, H292, A549 and CAL-27 seemed to be less sensitive, with DEFs ranging from 1.02 to 2.67. These cells were also less sensitive to the cytotoxic effects of single-agent gemcitabine. Amifostine with AP clearly showed a protective effect in combination with gemcitabine/radiotherapy. In H292 cells, the protection factor (PF) of amifostine after treatment with gemcitabine and radiotherapy varied from 1.64 to 1.86. In ECV304 cells, the PF varied from 2.20 to 2.29. In conclusion, a clear concentration- and cell line-dependent radiosensitising effect of gemcitabine was observed in all cell lines. Amifostine with AP showed protection against the radiosensitising effect of gemcitabine. If the protection in vivo indeed occurs selectively in normal tissues, then amifostine could prevent or strongly minimise the increased toxicity resulting from the radiosensitising effect of the combination of gemcitabine and radiotherapy, without influencing the antitumour effect.
Asunto(s)
Amifostina/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapéutico , Neoplasias/tratamiento farmacológico , Fármacos Sensibilizantes a Radiaciones/uso terapéutico , Fosfatasa Alcalina/farmacología , Terapia Combinada , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Humanos , Dosificación Letal Mediana , Neoplasias/radioterapia , Células Tumorales Cultivadas , GemcitabinaRESUMEN
To investigate the relation between the prevalence of human papillomavirus (HPV) and age in cervical cancer patients, material from 93 patients with Ia-IIb cervical carcinoma was analyzed for the presence of HPV by both type-specific and general primer polymerase chain reaction. Patients were divided into 2 groups: 64 years or younger, and 65 years and older. There was no statistically significant difference in either the prevalence of HPV DNA or distribution of genotypes amongst the 2 groups. Therefore, HPV detection can be equally well used in the management and follow-up of elderly cervical cancer patients.