%0 Journal Article %T Distinct expression patterns of the E3 ligase SIAH-1 and its partner Kid/KIF22 in normal tissues and in the breast tumoral processes. %+ Hématologie -Immunologie -Cibles thérapeutiques %+ Chu (saint-Louis)/inserm %+ Sección Bioquímica %A Bruzzoni-Giovanelli, Heriberto %A Fernandez, Plinio %A Veiga, Lucía %A Podgorniak, Marie-Pierre %A Powell, Darren %A Candeias, Marco %A Mourah, Samia %A Calvo, Fabien %A Marín, Mónica %Z This work was supported by the action U03S03 from the ECOS-Sud program (France-Uruguay). Comisión Honoraria de Lucha Contra el Cáncer (CHLCC), Uruguay. %< avec comité de lecture %@ 0392-9078 %J Journal of Experimental and Clinical Cancer Research %I BioMed Central %V 29 %N 1 %P 10 %8 2010 %D 2010 %R 10.1186/1756-9966-29-10 %M 20144232 %Z Life Sciences [q-bio]/CancerJournal articles %X SIAH proteins are the human members of an highly conserved family of E3 ubiquitin ligases. Several data suggest that SIAH proteins may have a role in tumor suppression and apoptosis. Previously, we reported that SIAH-1 induces the degradation of Kid (KIF22), a chromokinesin protein implicated in the normal progression of mitosis and meiosis, by the ubiquitin proteasome pathway. In human breast cancer cells stably transfected with SIAH-1, Kid/KIF22 protein level was markedly reduced whereas, the Kid/KIF22 mRNA level was increased. This interaction has been further elucidated through analyzing SIAH and Kid/KIF22 expression in both paired normal and tumor tissues and cell lines. It was observed that SIAH-1 protein is widely expressed in different normal tissues, and in cells lines but showing some differences in western blotting profiles. Immunofluorescence microscopy shows that the intracellular distribution of SIAH-1 and Kid/KIF22 appears to be modified in human tumor tissues compared to normal controls. When mRNA expression of SIAH-1 and Kid/KIF22 was analyzed by real-time PCR in normal and cancer breast tissues from the same patient, a large variation in the number of mRNA copies was detected between the different samples. In most cases, SIAH-1 mRNA is decreased in tumor tissues compared to their normal counterparts. Interestingly, in all breast tumor tissues analyzed, variations in the Kid/KIF22 mRNA levels mirrored those seen with SIAH-1 mRNAs. This concerted variation of SIAH-1 and Kid/KIF22 messengers suggests the existence of an additional level of control than the previously described protein-protein interaction and protein stability regulation. Our observations also underline the need to re-evaluate the results of gene expression obtained by qRT-PCR and relate it to the protein expression and cellular localization when matched normal and tumoral tissues are analyzed. %G English %2 https://inserm.hal.science/inserm-00668466/document %2 https://inserm.hal.science/inserm-00668466/file/1756-9966-29-10.pdf %L inserm-00668466 %U https://inserm.hal.science/inserm-00668466 %~ INSERM %~ UNIV-PARIS7 %~ APHP %~ UNIV-PARIS