Ki-1/57 and CGI-55 ectopic expression impact cellular pathways involved in proliferation and stress response regulation

Publication date: December 2014 Source:Biochimica et Biophysica Acta (BBA) - Molecular Cell Research, Volume 1843, Issue 12 Author(s): Fernanda C. Costa , Ângela Saito , Kaliandra A. Gonçalves , Pedro M. Vidigal , Gabriela V. Meirelles , Gustavo C. Bressan , Jörg Kobarg Ki-1/57 (HABP4) and CGI-55 (SERBP1) are regulatory proteins and paralogs with 40.7% amino acid sequence identity and 67.4% similarity. Functionally, they have been implicated in the regulation of gene expression on both the transcriptional and mRNA metabolism levels. A link with tumorigenesis is suggested, since both paralogs show altered expression levels in tumor cells and the Ki-1/57 gene is found in a region of chromosome 9q that represents a haplotype for familiar colon cancer. However, the target genes regulated by Ki-1/57 and CGI-55 are unknown. Here, we analyzed the alterations of the global transcriptome profile after Ki-1/57 or CGI-55 overexpression in HEK293T cells by DNA microchip technology. We were able to identify 363 or 190 down-regulated and 50 or 27 up-regulated genes for Ki-1/57 and CGI-55, respectively, of which 20 were shared between both proteins. Expression levels of selected genes were confirmed by qRT-PCR both after protein overexpression and siRNA knockdown. The majority of the genes with altered expression were associated to proliferation, apoptosis and cell cycle control processes, prompting us to further explore these contexts experimentally. We observed that overexpr...
Source: Biochimica et Biophysica Acta (BBA) Molecular Cell Research - Category: Molecular Biology Source Type: research