The molecular mechanisms underlying the multiresistant phenotype of leukemic and other cancer cells are incompletely understood. We used expression arrays to reveal differences in the gene expression profiles of an apoptosis-resistant T cell leukemia clone (A4) and normally apoptosis-sensitive parental Jurkat cells. CD73 (ecto-5′-nucleotidase) was the most up-regulated gene in the resistant A4 cell clone. A4 cells displayed CD73 surface expression and significant ecto-5′-nucleotidase activity. The role of CD73 was confirmed by transfection of wild-type CD73 into native Jurkat cells, which led to specific resistance against TRAIL-induced apoptosis, but not other types of apoptosis. The protective role of CD73 was further confirmed by small interfering RNA-mediated down-regulation of CD73, restoring TRAIL sensitivity. CD73-mediated resistance was independent of enzymatic activity of CD73, but was reliant on the anchoring of the protein to the membrane via GPI. We suggest that the inhibition of TRAIL signaling works through interaction of CD73 with death receptor 5, as CD73 and death receptor 5 could be coimmunoprecipitated and were shown to be colocalized in the plasma membrane by confocal microscopy. We propose that CD73 is a component of multiresistance machinery, the transcription of which is activated under selective pressure of the immune system.

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The article describes the uniaxial compression tests on rock salt samples under monotonic loading, which were carried out with the synchronous record of changes in thermal radiation and mechanical parameters. A relationship between the nonlinear deformation stages and the features of thermomechanical processes is found. The rate of change in rock stress state is shown to affect the information value of variations in the attendant infrared radiation. The experimental results point out the possibility of using the method in monitoring of the real geomechanical objects.The deformation and failure processes in solids, including geomaterials, are accompanied by the wide electromagnetic spectrum: from radio-wave pulses [1, 2] and infrared radiation [3, 4] to luminescent flashes [5]. The current methods are based on using the mentioned effects, which appear under changes in the state of geomaterials and allow the information of them to be found [6][7][8][9][10][11].To diagnose the stress state of different materials for both research and technological purposes, two well-known thermodynamic effects are applied. They involve the change in temperature of a solid upon varying the first invariant of stress tensor [3,12] and the relationship between the intensity of infrared radiation from a solid surface and the temperature [3,13]. As previously shown [8-10], such approach can become effective for the contactless measurements of elastic stresses in geomaterials.The purpose of the present paper is to consider the possibility for identifying the deformation processes in geomaterials under the wider range of conditions, namely, under the stresses coming to the elastic and ultimate strengths, by measuring the thermal radiation.The experimental stand is shown in Fig. 1. All tests were carried out with the Instron 150LX press, which allows implementing the "hard" and "soft" modes of uniaxial loading and provides the automated and synchronous registration of changes in the mechanical parameters and the corresponding variations in infrared radiation intensity.As in [8-10], RTN-31 is used as the primary infrared radiation detector [14] meant for the contactless measurement of optical radiation intensity in the infrared spectrum of wave lengths. IR radiation detector 1 is fixed approximately at the center of sample 2 at a distance of 0.5-1 cm from its surface. M70P-S3 strain-gage 5 for measuring the changes in the force exerted on a sample is placed between plate 3 and base plate 4. Contrary to bench in [9, 10], the gauging stand includes longitudinal strain indicator 6 embedded into the loading press and located between plate 4 and the moving beam of the press. This gage allows one to obtain the relationships between the longitudinal stress 1 σ and longitudinal strain 1 ε , as well as to define the boundaries between the process stages and test the transitions by using the thermal radiation data.

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