Baculoviral IAP repeat-containing protein 5 (BIRC5) splice variant 2B mRNA (Survivin-2B mRNA)

Survivin-2B mRNA is a specific splice variant of the Baculoviral IAP repeat-containing protein 5 (BIRC5) gene, generated by the retention of a 69-base pair cryptic exon (exon 2B) from the second intron (NIH, 2023; MDPI, 2023). This alternative splicing event results in a protein isoform that contains an additional 23 amino acids within the Baculoviral IAP Repeat (BIR) domain, which is essential for its interaction with caspases and other regulatory proteins (AACR, 2011; ResearchGate, 2016). Unlike the wild-type survivin, which is a potent inhibitor of apoptosis and a regulator of mitosis, survivin-2B is frequently reported to have pro-apoptotic functions or a significantly reduced anti-apoptotic capacity, often acting as a naturally occurring antagonist to the wild-type form (NIH, 2023; WJG, 2011). In the context of cancer, survivin-2B mRNA is overexpressed in various malignancies, including ovarian, pancreatic, and breast cancers, and its expression levels have been linked to disease progression and resistance to chemotherapies such as taxanes (AACR, 2011; NIH, 2019). Therapeutic strategies targeting this molecule include antisense oligonucleotides (ASOs) and small interfering RNAs (siRNAs) designed to specifically degrade the survivin-2B mRNA, as well as peptide vaccines (e.g., SVN-2B) that utilize the unique protein sequence encoded by this variant to stimulate a cytotoxic T-lymphocyte (CTL) response against tumor cells (NIH, 2019; NIH, 2023).

Other names

Survivin-2BSurvivin-2betaBIRC5 variant 2BIRC5-2BBIRC5 transcript variant 2

Antisense-mediated mRNA degradation, induction of antigen-specific cytotoxic T-lymphocyte (CTL) response, and transcriptional suppression of the BIRC5 promoter.