Anti-FASLG monoclonal antibody, clone 14C2 [R-PE]

The acquisition of resistance towards FAS-mediated apoptosis may be required for tumor formation. Tumors from various histological origins exhibit FAS mutations, the most frequent being hematological malignancies. However, data regarding FAS mutations or FAS signaling alterations are still lacking in precursor T-cell lymphoblastic lymphomas (T-LBLs). The available data on acute lymphoblastic leukemia, of precursor origin as well, indicate a low frequency of FAS mutations but often report a serious reduction in FAS-mediated apoptosis as well as chemoresistance, thus suggesting the occurrence of mechanisms able to deregulate the FAS signaling pathway, different from FAS mutation. Our aim at this study was to determine whether FAS-mediated apoptotic signaling is compromised in human T-LBL samples and the mechanisms involved. This study on 26 T-LBL samples confirms that the FAS system is impaired to a wide extent in these tumors, with 57.7% of the cases presenting any alteration of the pathway. A variety of mechanisms seems to be involved in such alteration, in order of frequency the downregulation of FAS, the deregulation of other members of the pathway and the occurrence of mutations at FAS. Considering these results together, it seems plausible to think of a cumulative effect of several alterations in each T-LBL, which in turn may result in FAS/FASLG system deregulation. Since defective FAS signaling may render the T-LBL tumor cells resistant to apoptotic cell death, the correct prognosis, diagnosis and thus the success of anticancer therapy may require such an in-depth knowledge of the complete scenario of FAS-signaling alterations.

Antiphospholipid antibodies, a maternal risk factor for preeclampsia, increase shedding of necrotic trophoblast debris from the placenta, leading to endothelial dysfunction. Using Affymetrix HGU133 Plus 2 microarrays we found changes in the transcriptome of placental explants treated with antiphospholipid antibodies, including mRNAs BCL2L1, MCL1, PDCD2L, FASLG, SEMA6A, PRKCE and TRAIL that are involved in the regulation of apoptosis. Quantitative real-time RT-PCR and immunohistochemistry confirmed a reduction in TRAIL expression in response to antiphospholipid antibodies. These results may help to understand how antiphospholipid antibodies affect trophoblast cell death and how the antibodies could contribute to the pathogenesis of preeclampsia. (c) 2012 Elsevier Ireland Ltd. All rights reserved.