Several matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) were studied in highly invasive (MDA-MB-231) and slightly invasive (MCF-7, T47D, BT-20) breast cancer cell lines. Investigations were carried out at the protein level and/or at the mRNA level, either in cells cultured as monolayers on plastic, or in cells seeded on a thin layer of Matrigel basement membrane matrix. Analysis of MMP expression by RT-PCR showed expression of MMP-1. MMP-3, and MMP-13 in highly invasive MDA-MB-231 cells, but not in slightly invasive cell lines. The extracellular secretion of MMP-1 and MMP-3 by MDA-MB 231 cells could be also shown by ELISA. TIMP-1 and TIMP-2 mRNAs were found in all cell lines, however, the extracellular secretion of both TIMPs was much higher in MDA-MB-231 cells than in the other cell lines. When the cells were cultured on Matrigel matrix, MMP-9 expression was induced in MDA-MB-231 cells only, as assessed by RT-PCR and zymography experiments. The invasive potential of MDA-MB-231 cells evaluated in vitro through Matrigel was significantly inhibited by the MMP inhibitor BB-2516, by 25% and 50% at the concentrations of 2 x 10(-6) M and 10(-5) M, respectively. In conclusion, our data show that highly invasive MDA-MB-231 cells but not slightly invasive T47D, MCF-7 and BT-20 cells express MMP-1, MMP-3, MMP-9 and MMP-13. MMP-9 which is specifically up-regulated by cell contact to Matrigel, may play a key role in the invasiveness of MDA-MB-231 cells through basement membranes.
Self-broadening and shifting of methyl fluoride CH312F have been investigated in the 50–408 GHz range for the rotational transitions J=0→1, J=1→2, J=2→3, J=5→6, and J=7→8 and for their ΔM=0 and ΔM=±1 Stark components, as they were resolved by an appropriate field. The different results obtained for M-degenerated and M-resolved cases, as well as the M dependence of the results has been interpreted theoretically within semiclassical perturbative approximations. Evidence of collisional coupling effects between Stark components was obtained.
LAL 04-99Exotic hadrons made of five quarks (pentaquarks) are searched for in hadronic Z decays collected by the ALEPH detector at LEP. No significant signal is observed. At 95% C.L., upper limits are set on the production rates N of such particles and their charge-conjugate state per Z decay: N Theta(1535)+ . BR(Theta(1535)^+ -> pK0s < 6.2 x 10^-4, N Xi(1862)-- . BR(Xi(1862)^-- -> xi^- pi^-) < 4.5 x 10^-4, N Xi(1862)^0 . BR(Xi(1862)^0 -> Xi^-pi^+ < 8.9 x 10^-4, N Theta_c(3100)^0 . BR(Theta_c(3100)^0 -> D*-p) < 6.3 x 10^-4, N Theta_c(3100)^0 . BR(Theta_c(3100)^0 -> D^-p) < 31 x 10^-4
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