Anti-CASP9 polyclonal antibody

The present study reports the synthesis and crystal structures of Cu(II) complexes with pyridoxal S-allyldithiocarbazate (H2L1) and pyridoxal thiosemicarbazones (H2L2=pyridoxal-N-4-phenyl-3-thiosemicarbazone and H2L3=pyridoxal-N-4-semicarbazone). The single-crystal X-ray study reveals that in all cases, the Schiff base coordinated tridentately through the ONS-donor atoms, resulting in distorted square planar coordination geometries with the copper atoms. The Cu(II) complexes with pyridoxal dithiocarbazate, [Cu(HL1)Cl]H2O and [Cu(HL1)Br]H2O, as well as three complexes with pyridoxal thiosemicarbazone, [Cu(HL2)Cl]dmf, [Cu(HL2)Br]H2Odmf and [Cu(H2L3)Br]BrH2O, were also characterized by spectroscopic and physical-chemical analyses. The cytotoxicity of the complexes toward two kinds of cancerous cells (Ehrlich and S-180 cells) was evaluated by an MTT assay. The complex [Cu(H2L3)Br]BrH2O was selected to study both the cellular and molecular mechanisms underlying its promising cytotoxicity. The Hoechst 33342/PI dual-staining assay showed the typical apoptotic morphology of cancer cells, and the RT-qPCR analysis revealed that the expressions of Bax, Casp3, Casp8, Casp9 and TP53 were markedly increased in both the Ehrlich and S-180 cells exposed to 10M for 3h. According to our results, this complex induces cell death through apoptosis, showing potential as a future drug against cancer.

Antiestrogens are effective therapies for the management of many estrogen receptor-alpha (ER)-positive breast cancers. Nonetheless, both de novo and acquired resistance occur and remain major problems in the clinical setting. IFN. is an inflammatory cytokine that induces the expression and function of IFN regulatory factor 1 (IRF1), a tumor suppressor gene that can increase antiestrogen responsiveness. We show that IFN gamma, but not IFN alpha, IFN beta, or fulvestrant (ICI; ICI 182,780; Faslodex), induces IRF1 expression in antiestrogen-resistant MCF7/ LCC9 and LY2 cells. Moreover, IFN gamma restores the responsiveness of these cells to fulvestrant. Increased IRF1 activation suppresses NF-kappa B p65 (RELA) activity, inhibits the expression of prosurvival (BCL2, BCL-W), and induces the expression of proapoptotic members (BAK, mitochondrial BAX) of the BCL2 family. This molecular signaling is associated with the activation of signal transducer and activator of transcription 1 and leads to increased mitochondrial membrane permeability; activation of caspase-7 (CASP7), CASP8, and CASP9; and induction of apoptosis but not autophagy. Whereas antiestrogen-resistant cells are capable of inducing autophagy through IFN-mediated signaling, their ability to do so through antiestrogen-regulated signaling is lost. The abilities of IFN gamma to activate CASP8, induce apoptosis, and restore antiestrogen sensitivity are prevented by siRNA targeting IRF1, whereas transient overexpression of IRF1 mimics the effects of IFN gamma treatment. These observations support the exploration of clinical trials combining antiestrogens and compounds that can induce IRF1, such as IFN gamma, for the treatment of some ER-positive breast cancers. Mol Cancer Ther; 9(5); 1274-85. (C) 2010 AACR.