Etiologic factors associated with cancer include improper diet, genetic predisposition and environment conditions; the majority of human cancers result from exposure to environmental carcinogens (Reddy et al., 2003). Glycosylation is the most frequent form of post-translational modifications of proteins (Chen et al., 2007; Rek et al., 2009) and alterations in the pattern of cell surface glycoconjugates

are remarkably characteristic of malignant cells associated with CP-868596 in vivo induction of tissue invasion and metastasis (Hakomori, 2002; Kobata and Amano, 2005; Reis et al., 2010). Due to their peripheral location, oligosaccharide epitopes of glycoproteins and glycolipids are recognized by membrane-anchored carbohydrate-recognition domains of different molecules, including lectins (Jiménez-Castells et al., 2008). Lectins comprise proteins or glycoproteins which bind specifically to mono- or oligosaccharides and glycoconjugates (Wu et al., 2009). Carbohydrate-specificity of lectins has been shown to be a versatile and useful molecular tool for study of glycoconjugates on the cell surface, in particular the changes that cells suffer

in malignancy (Sharon and Lis, 2004). Thus, lectins are excellent candidates to be explored in cancer research as therapeutic agents. Lectins from snake venoms exhibit learn more several biological activities like the ability to inhibit integrin-dependent proliferation, migration and invasion of tumor cells (Sarray et al., 2004, 2007) as well as the ability to reduce the growth of tumor and endothelial cells (Carvalho et al., 2001). The induction of tumor cell apoptosis by snake venom lectins has

been observed (Nolte et al., 2012). However, different mechanisms of action induction of apoptosis can be involved and therefore need to be investigated. The BlL is a galactoside-binding lectin Loperamide isolated from the venom of Bothrops leucurus (white-tailed-jararaca). BlL is a Ca2+-dependent protein of 30 kDa composed of dissulfide-linked dimers of 15 kDa and exhibits antibacterial activity against human pathogenic Gram-positive bacteria ( Nunes et al., 2011). Apoptosis (programmed cell death) is an essential cellular homeostasis mechanism that ensures the correct development and function of multi-cellular organisms. However, cancer cells show a reduced sensitivity towards apoptosis and tumors are dependent on the mechanisms of this resistance to persist and continue development. Therefore, the discovery of drugs that selectively affect the balance of tumor cellular functions towards apoptosis is of enormous therapeutic interest. According Taraphdar et al. (2001), induction of apoptosis is an important strategy for cancer therapy and prevention.