27 research outputs found
Apoptotic HPV Positive Cancer Cells Exhibit Transforming Properties
Previous studies have shown that DNA can be transferred from dying engineered cells to neighboring cells through the phagocytosis of apoptotic bodies, which leads to cellular transformation. Here, we provide evidence of an uptake of apoptotic-derived cervical cancer cells by human mesenchymal cells. Interestingly, HeLa (HPV 18+) or Ca Ski (HPV16+) cells, harboring integrated high-risk HPV DNA but not C-33 A cells (HPV-), were able to transform the recipient cells. Human primary fibroblasts engulfed the apoptotic bodies effectively within 30 minutes after co-cultivation. This mechanism is active and involves the actin cytoskeleton. In situ hybridization of transformed fibroblasts revealed the presence of HPV DNA in the nucleus of a subset of phagocytosing cells. These cells expressed the HPV16/18 E6 gene, which contributes to the disruption of the p53/p21 pathway, and the cells exhibited a tumorigenic phenotype, including an increased proliferation rate, polyploidy and anchorage independence growth. Such horizontal transfer of viral oncogenes to surrounding cells that lack receptors for HPV could facilitate the persistence of the virus, the main risk factor for cervical cancer development. This process might contribute to HPV-associated disease progression in vivo
Microscopie référencée en position : suivi site à site de l'évolution des cultures cellulaires
Microscopie référencée en position : une alternative à la vidéo-microscopie
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Pseudo-Periodic Encryption of Extended 2-D Surfaces for High Accurate Recovery of any Random Zone by Vision
International audienceThis article presents a binary position encoding method for extended two-dimensional surfaces. Position encryption is based on linear feedback shift register sequences inserted within a periodic frame of spots. The position and orientation of any local view is retrieved accurately with respect to the encrypted surface. Image processing combines phase computations with binary image feature analysis. Measurement resolution is in the range of 10-2 pixel in position and 10-3 degree for in-plane orientation. The method is used as a visual sensor in a position control loop applied to fluorescence optical microscopy for the recovery of cells of interest within culture dishes
Position-referenced microscopy: Regions of interest localization and subpixel image comparison by means of pseudo-random patterns embedded in cell culture boxes.
International audienceThis work presents micro-grids integrated to cell culture boxes. These grids allow the systematic registration of the position of a zone observed by optical microscopy in a such way that it is possible to find it again easily for new observations for instance after culture on drug injection. The position knowledge allows also the numerical superimposition of recorded images in a common position reference system with a sub-pixel precision. It become thus straightforward to perform a site by site analysis of the possible evolutions that may have occurred in the biological medium