CD133, CD15/SSEA-1, CD34 or side populations do not resume tumor-initiating properties of long-term cultured cancer stem cells from human malignant glio-neuronal tumors

<p>Abstract</p> <p>Background</p> <p>Tumor initiating cells (TICs) provide a new paradigm for developing original therapeutic strategies.</p> <p>Methods</p> <p>We screened for TICs in 47 human adult brain malignant tumors. Cells forming floating spheres in culture, and endowed with all of the features expected from tumor cells with stem-like properties were obtained from glioblastomas, medulloblastoma but not oligodendrogliomas.</p> <p>Results</p> <p>A long-term self-renewal capacity was particularly observed for cells of malignant glio-neuronal tumors (MGNTs). Cell sorting, karyotyping and proteomic analysis demonstrated cell stability throughout prolonged passages. Xenografts of fewer than 500 cells in Nude mouse brains induced a progressively growing tumor. CD133, CD15/LeX/Ssea-1, CD34 expressions, or exclusion of Hoechst dye occurred in subsets of cells forming spheres, but was not predictive of their capacity to form secondary spheres or tumors, or to resist high doses of temozolomide.</p> <p>Conclusions</p> <p>Our results further highlight the specificity of a subset of high-grade gliomas, MGNT. TICs derived from these tumors represent a new tool to screen for innovative therapies.</p

On the use of error correcting codes in secured circuits

The robustness of a circuit designed for securityrelated applications depends on its capability to globally resist to various types of attacks, based either on observation (e.g. DPA) or perturbation (e.g. injecting faults with a laser). In the case of perturbations, strategies can be based on protections aiming either at detecting the attack or at trying to maintain a correct behavior. This paper discusses characteristics of these two types of approaches when using information redundancy and in particular Hamming codes

Error detection code efficiency for secure chips

ISBN : 1-4244-0395-2The robustness of a chip designed for security-related applications depends on its capability to globally resist to various types of attacks. This paper deals with protections against non invasive or semi invasive attacks. The two main categories are attacks based on power consumption (either by monitoring the current, e.g. DPA, or by monitoring the electromagnetic emissions, i.e. EMA) and attacks based on the injection of faults during the application execution (DFA). Error detecting codes are often proposed as a basis for countermeasures against DFA. This paper discusses the influence of the choice of the code on the global robustness of the circuit, taking into account both DPA and DFA

Analysis of Laser-Based Attack Effects on a Synchronous Circuit

ISBN : 978-1-4244-1825International audienceCircuits used in security-related applications must be robust against various types of attacks. One recent and powerful threat is based on the perturbation of the circuit during the application execution. Lasers are the most efficient and precise equipment allowing a hacker to perform such fault-based attacks. Implemented protections are on-line detection mechanisms, often based on error detecting codes to achieve low overheads. Parity-based schemes have in particular been proposed as protections for cryptographic functions, but very few data are available in the open literature about the actual efficiency of such schemes. This paper provides such data, obtained during laserbased attacks on three versions of a synchronous circuit. It is shown that a classical protection technique can leave open doors to an attacker, and that multiple faults must be taken into account when designing the protections. Several other aspects of the effects induced by the laser are discussed in details

On the use of information redundancy when designing secure chips

The robustness of a chip designed for security-related applications depends on its capability to globally resist to various types of attacks. Fault-based attacks are clasically countered by information redundancy (data encoding). This paper shows that codes with similar detection efficiency can have very different characteristics with respect to other types of attacks based on power consumption analysis