RESUMEN
Mechanisms of intrinsic resistance of serous ovarian cancers to standard treatment with carboplatin and paclitaxel are poorly understood. Seventeen primary serous ovarian cancers classified as responders or nonresponders to standard treatment were screened with DigiWest protein array analysis for 279 analytes. Histone methyl transferase EZH2, an interaction partner of ataxia telangiectasia mutated (ATM), was found as one of the most significantly represented proteins in responsive tumors. Survival analysis of 616 patients confirmed a better outcome in patients with high EZH2 expression, but a worse outcome in patients with low EZH2 and high-ATM-expressing tumors compared with patients with low EZH2 and low-ATM-expressing tumors. A proximity ligation assay further confirmed an association between ATM and EZH2 in tumors of patients with an increased disease-free survival. Knockdown of EZH2 resulted in treatment-resistant cells, but suppression of both EZH2 and ATM, or ATM alone, had no effect. DigiWest protein analysis of EZH2-knockdown cells revealed a decrease in proteins involved in mitotic processes and checkpoint regulation, suggesting that deregulated ATM may induce treatment resistance. IMPLICATIONS: Ovarian cancer is a malignancy with high mortality rates, with to date, no successful molecular characterization strategies. Our study uncovers in a comprehensive approach the involvement of checkpoint regulation via ATM and EZH2, potentially providing a new therapeutic perspective for further investigations.
Asunto(s)
Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Carboplatino/farmacología , Cistadenocarcinoma Seroso/tratamiento farmacológico , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Neoplasias Ováricas/tratamiento farmacológico , Paclitaxel/farmacología , Anciano , Proteínas de la Ataxia Telangiectasia Mutada/genética , Cistadenocarcinoma Seroso/genética , Cistadenocarcinoma Seroso/metabolismo , Daño del ADN , ADN de Neoplasias/genética , Resistencia a Antineoplásicos , Proteína Potenciadora del Homólogo Zeste 2/deficiencia , Proteína Potenciadora del Homólogo Zeste 2/genética , Femenino , Humanos , Neoplasias Ováricas/genética , Neoplasias Ováricas/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transducción de SeñalRESUMEN
Among various nanoparticles tested for pharmacological applications over the recent years, graphene quantum dots (GQDs) seem to be promising candidates for the construction of drug delivery systems due to their superior biophysical and biochemical properties. The subcellular fate of incorporated nanomaterial is decisive for transporting pharmaceuticals into target cells. Therefore a detailed characterization of the uptake of GQDs into different breast cancer models was performed. The demonstrated accumulation inside the endolysosomal system might be the reason for the particles' low toxicity, but has to be overcome for cytosolic or nuclear drug delivery. Furthermore, the penetration of GQDs into precision-cut mammary tumor slices was studied. These constitute a far closer to reality model system than monoclonal cell lines. The constant uptake into the depth of the tissue slices underlines the systems' potential for drug delivery into solid tumors.
Asunto(s)
Neoplasias de la Mama/metabolismo , Grafito/metabolismo , Puntos Cuánticos/metabolismo , Neoplasias de la Mama/patología , Células Epiteliales/metabolismo , Grafito/química , Humanos , Nanoestructuras/química , Tamaño de la Partícula , Puntos Cuánticos/química , Fracciones Subcelulares/metabolismo , Técnicas de Cultivo de Tejidos , Células Tumorales CultivadasRESUMEN
Diagnostic leukapheresis (DLA) is based on continuous centrifugation that collects mononuclear cells from peripheral blood with a density of 1.055-1.08 g/ml. As epithelial cells have a similar density, DLA cocollects circulating tumor cell (CTCs) along with the targeted mononuclear cells. Here, we report on our single center experience applying DLA in 40 nonmetastatic and metastatic breast cancer patients and its impact on CTC detection. We found that the use of just 5% of the DLA product (corresponding to a median peripheral blood volume of around 60 ml) in the CellSearch® assay already leads to a significant increase in CTC detection frequency and yield. The implementation of the method was unproblematic, and we did not observe any adverse events in our patient cohort. Extrapolating the CTC counts in the DLA samples to the whole DLA product indicated that enormous CTC numbers could be harvested by this approach (around 205x more CTCs than in the 7.5 ml blood sample in M1 patients). In conclusion, DLA is a clinically safe method to collect CTCs from liters of blood enabling a real liquid biopsy. Yet, further technical developments are required to process whole DLA products and exploit the full potential of this approach. As it is foreseeable that DLA will be used by several groups, and hopefully ultimately brought to the patients in a routine setting, we discuss recommendations on the minimum of required information for reporting on DLAs to allow comparison across different approaches. © 2018 International Society for Advancement of Cytometry.
