RESUMEN
BACKGROUND: We reported recently the clinical efficiency of interferon (IFN)-α/5-fluorouracil (5-FU) combination therapy in advanced hepatocellular carcinoma (HCC). However, prediction of the response to the combination therapy remains unsatisfactory. The aim of this study was to investigate the anti-tumour effects of microRNA (miR)-21 on the sensitivity of HCC cells to IFN-α/5-FU and whether miR-21 can be used as a predictor of the response to such therapy in HCC. METHODS: Changes in the sensitivity of HCC cells (PLC/PRF/5 and HepG2) to IFN-α/5-FU were examined after transfection with pre-miR-21 or anti-miR-21. The correlation between miR-21 expression level, evaluated by qRT-PCR, and response to the therapy was also investigated in clinical HCC specimens. RESULTS: Hepatocellular carcinoma cells transfected with pre-miR-21 were significantly resistant to IFN-α/5-FU. Annexin V assay showed that the percentage of apoptotic cells was significantly lower in cells transfected with pre-miR-21 than control cells. Transfection of anti-miR-21 rendered HCC cells sensitive to IFN-α/5-FU, and such sensitivity was weakened by transfection of siRNAs of target molecules, PETN and PDCD4. miR-21 expression in clinical HCC specimens was significantly associated with the clinical response to the IFN-α/5-FU combination therapy and survival rate. CONCLUSIONS: The miR-21 in HCC cell lines and clinical HCC samples is a significant modulator of the anti-tumour effect of IFN-α and 5-FU. This suggests that miR-21 is a potentially suitable marker for the prediction of the clinical response to the IFN-α/5-FU combination therapy.
Asunto(s)
Carcinoma Hepatocelular/tratamiento farmacológico , Neoplasias Hepáticas/tratamiento farmacológico , MicroARNs/genética , Antineoplásicos/antagonistas & inhibidores , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/mortalidad , Carcinoma Hepatocelular/patología , División Celular/efectos de los fármacos , Cartilla de ADN , Evaluación Preclínica de Medicamentos , Resistencia a Medicamentos , Resistencia a Antineoplásicos , Fluorouracilo/antagonistas & inhibidores , Fluorouracilo/uso terapéutico , Humanos , Inmunohistoquímica , Interferón-alfa/antagonistas & inhibidores , Interferón-alfa/uso terapéutico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/patología , MicroARNs/farmacología , ARN Mensajero/genética , ARN Neoplásico/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Tasa de Supervivencia , TransfecciónRESUMEN
The aim of this study was to investigate whether man-made mineral fibers (MMMF) induce apoptosis of human peripheral blood mononuclear cells (PBMC), as we recently demonstrated for chrysotile B. In vitro cultivation of PBMC with various MMMF as well as chrysotile B clearly produced apoptotic cells. The alteration of the expression for apoptosis related genes at the mRNA level during in vitro cultures of PBMC with various MMMF revealed upregulation of Flice and Apaf-1 genes and down regulation of TNF receptor 1 and Bid genes. These results indicate that MMMF induce apoptosis of PBMC in a similar manner to chrysotile B. However, the process may be mediated not only by the Fas-related apoptotic pathway but also a mitochondrial pathway. Thus, one should be aware that respiratory and immunological abnormalities may occur in workers who are exposed to MMMFs.
Asunto(s)
Apoptosis/efectos de los fármacos , Asbestos Serpentinas/farmacología , Leucocitos Mononucleares/efectos de los fármacos , Fibras Minerales/toxicidad , Adulto , Antígenos CD/biosíntesis , Antígenos CD/genética , Apoptosis/genética , Caspasa 8 , Caspasa 9 , Caspasas/biosíntesis , Caspasas/genética , ADN Complementario/genética , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , ARN Mensajero/biosíntesis , Receptores del Factor de Necrosis Tumoral/biosíntesis , Receptores del Factor de Necrosis Tumoral/genética , Receptores Tipo I de Factores de Necrosis Tumoral , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ubiquitinas/biosíntesis , Ubiquitinas/genéticaRESUMEN
Silica and related substances such as silicate have been proven to possess "adjuvant effects". We have previously reported a finding of polyclonal human T cell activation induced by silicate as a superantigen in vitro. In this study, we observed activation-induced cell death in human lymphocytes after stimulation with chrysotile, a kind of silicate. Apoptotic cells were detected flow cytometrically using the TUNEL assay, and the maximum appearance of TUNEL positive cells occurred on day 4 of incubation. Simultaneously the manifestation of small-sized cells in the specimens increased implying apoptosis. Fas expression on lymphocytes increased to day 3 of incubation with chrysotile, and then spontaneously decreased on day 4 when remarkable apoptosis could be detected. Based on these results it is conceivable that activation-induced cell death occurred through Fas-Fas ligand interaction in lymphocytes after stimulation with silicate in a concentration with which no acute cytotoxicity has been detected. Whether and how the repeated apoptosis in definite clones of lymphocytes causes the induction of sFas synthesis need clarification.