RESUMEN
The human breast cancer-associated gene (BCA3) was first discovered in breast and prostate cancer cells lines. In vivo studies have shown that BCA3 is mainly expressed in breast tumor cells and not in normal breast and prostate tissues. To date, 3 splice variants of BCA3 have been reported: a double-absent variant lacking exon 3 and exon 5 (BCA3-1), an exon 3-absent variant (BCA3-2), and full-length BCA3. In this study, we investigated whether a novel BCA3 splice variant exists that lacks only the exon 5-encoding sequence. BCA3 variant splices were subcloned and sequenced using reverse transcription-polymerase chain reaction. The preliminary biological functions of the splices were identified using confocal microscopy and a luciferase assay. The absence of exon 3 and exon 5 influenced the subcellular localization of BCA3 and nuclear factor kappa B (NF-kB)-dependent gene expression. Exon 3 and exon 5 of BCA3 may function together to provide a nuclear localization signal or transport sequence to enter the nucleus, and exon 3 may contain specific sequence(s) or domain(s) that influence the NF-κB signal cascade. The discovery of novel BCA3 splicing indicates a new cancer research area, which may increase the understanding of cancer generation and development.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Nucleares/metabolismo , Empalme del ARN , Proteínas Adaptadoras Transductoras de Señales/genética , Línea Celular , Clonación Molecular , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Exones , Humanos , FN-kappa B/metabolismo , Proteínas Nucleares/genética , FosforilaciónRESUMEN
Type 1 diabetes is a chronic progressive autoimmune disease characterized by mononuclear cell infiltration, with subsequent destruction of insulin-producing ß-cells. Studies have identified strong associations between type 1 diabetes and several chromosome regions, including 12q24. Association between type 1 diabetes and 12q24 arises from SNP rs3184504; rs3184504 is a nonsynonymous SNP in exon 3 of SH2B3 (also known as LNK). Nonobese diabetic (NOD) mice recapitulate many aspects of the pathogenesis of type 1 diabetes in humans and are therefore frequently used in studies addressing the cellular and molecular mechanisms of this disease. It is of interest to know whether there is a similar mutation of SH2B3 in NOD mice. We found that the SH2B3 mutation is absent in NOD mice. To our knowledge, this is the first report of the sequence and the protein levels of SH2B3 in NOD mice.