Survivin expression is associated with a poor prognosis in many cancers. While survivin is being studied as a potentially important target for cancer therapy, its many biological functions in both normal and cancerous cells remain to be fully elucidated. There are at least six specific survivin splice variants that have been identified to date which appear to be self-regulating and may have distinct functions. Several survivin peptide vaccines are currently under development by different groups. Survivin vaccine strategies for the most part have focused upon particular regional epitopes of the molecule that are bound by MHC class I and can lead to a cytotoxic T cell response. Immunotherapy targeting survivin is still at an early stage of development; however, several agents are progressing through early phase clinical trials. Recent studies using SurVaxM, a multi-epitope cryptic peptide, survivin, mimic show specific CD8+ T cell responses, as well as specific CD4+ T cell stimulation. Currently SurVaxM is in Phase I clinical trials designed to study its safety, tolerability and immunological effects in patients with survivin-positive recurrent malignant gliomas and multiple myeloma.Keywords: Survivin; Immunotherapy; Peptide; Vaccine; Apoptosis
SurvivinSurvivin is an 16.5 kDa intracellular protein that mediates a number of anti-apoptotic and oncogenic effects [1]. Survivin belongs to the inhibitor of apoptosis protein (IAP) family [2,3]. It acts in concert with the mitotic spindle apparatus to regulate cell division [4] and localizes to the spindle microtubule organizing center (MTOC) during the G2/M phase of the cell cycle [2,3,5]. Survivin has also been shown to modulate the function of a number of terminal effector cell death proteases (caspases) leading to an inhibition of apoptosis [3,[6][7][8]. Survivin expression is associated with a poor prognosis in many cancers [9,10]. While survivin is being studied as a potentially important target for cancer therapy, its many biological functions in both normal and cancerous cells remain to be fully elucidated.Survivin appears to function mainly as an anti-apoptotic molecule and its ability to interfere with p53 is one of its most studied molecular action [11][12][13]. However, the presence of survivin in the nucleus [14]; its interaction with the mitotic spindle [5]; its secondary localization inside mitochondria [15]; its presence in exosomes in plasma [16] observed exosomal release [17]; and the existence of circulating survivin-encoding mRNA [18,19]; and the existence of a many alternative mRNA splice variants all paint a complex picture of the molecule's possible actions. Although expressed during fetal development [1], survivin is rarely detectable in the normal tissues of adult organisms [20]. The cells of many different forms of cancer express survivin [1] and in some cases expression is related to tumor grade [9,10,21]. Survivin expression in tumors is associated with a high rate of disease recurrence and resistance to therapy, and it confers signific...