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We introduced a functional p16 cDNA into non-small cell lung cancer (NSCLC) cell lines expressing different combinations of normal and mutated p16, p53, and Rb genes via a recombinant adenovirus to determine the effect of exogenous p16 expression on cell growth. Analysis of p16-deficient cells infected with Adv/p16 identified growth arrest of the cells in the G0 - G1 phase early on. Apoptosis was identified to occur by the 5th day after infection which corresponded with increased p16 expression, reduced Rb expression, and increased Rb hypophosphorylation, but only occurred in cells expressing functional p53. Further analysis indicated that the expression of the anti-apoptotic protein bcl-2 was greatly reduced in the NSCLC cell lines H460 and A549 (both -p16, +p53, +Rb), again only by the 5th day after Adv/p16 infection, but no affect on Bax expression was observed. H1299 cells (-p16, -p53, +Rb) infected with Adv/p16 only exhibited apoptosis by an additional infection with Adv/p53 which also corresponded with a down-regulation of bcl-2. In addition, the infection of A549 cells with Adv/p16 followed by a subsequent infection with Adv/Rb lead to a significant decrease in apoptosis which correlated with an increase in bcl-2 expression. These studies suggest that p16 is capable of mediating apoptosis in NSCLC cell lines expressing wild-type p53, through a direct down-regulation of Rb and an indirect down-regulation of the anti-apoptotic protein bcl-2.

Figure 9. Simulation results in the terminator plane, i.e., looking from behind on Venus. The solar wind is orientated out of the plane (+x axis), the convective electric field is antiparallel to the (+z) axis and points away from the planet; thus, the background magnetic field completes the right-handed system (+y axis). Figure 10 displays (left) the solar wind density (nsw), (middle) the heavy ion density (nhi), and (right) the background magnetic field. An asymmetric bow shock, exhibiting a shocklet structure, is formed in front of the obstacle owing to the supersonic solar wind (left plot). The interplanetary magnetic field is draping around Venus generating an induced magnetotail on the nightside of the planet (right plot). See text for details. JOURNAL OF GEOPHYSICAL RESEARCH, VOL. 114, E00B98, doi:10.1029/2009JE003377, 2009

[1] We use data of the ASPERA-4 ion and electron spectrometers onboard Venus Express to determine the locations and shapes of the plasma boundaries (bow shock, ion composition boundary, and mantle) at Venus. We also investigate the variation of the terminator bow shock position as a function of the solar wind dynamic pressure and solar EUV flux. We compare the results with a 3-D hybrid simulation. In the hybrid model, ions are treated as individual particles moving in self-consistently generated electromagnetic fields and electrons are modeled as a massless charge neutralizing fluid. The planetary heavy ion plasma is generated by an oxygen ionosphere and exosphere adapted to a profile, which depends on the solar zenith angle (Chapman layer). A comparison between observations and simulations indicates that the hybrid model is able to produce an adequate picture of the global plasma environment at Venus. The positions of the plasma boundaries are well reproduced by the model but a significant disagreement appears in the absolute values of the considered parameters.