Pathophysiological Effects of Lycosa erythrognatha Derived Peptide LyeTxI-b on RKO-AS-45-1 Colorectal Carcinoma Cell Line Using the Chicken Chorioallantoic Membrane Model

The synthetic peptide derived from a spider toxin, Lycosa erithrognatha , LyeTxI-b, has known antitumoral and antiangiogenic activity. So, in this study we evaluated their effect on colorectal cancer (CRC), using the chicken chorioallantoic membrane (CAM) model for tumor development. On the 11th day of embryo development, the eggs were opened and the cell culture of RKO-AS-45-1 was instilled on the CAM surface and the eggs were reincubated for more 48 h. Sequentially, the LyeTxI-b was applied over the CAM. Cisplatin and phosphate-buffered saline (PBS) pH 7.4 were used as positive and negative controls, respectively (n = 6). On the 14th day of embryo development, the CAM was photographed and samples were analyzed by histology and immunohistochemistry. Lastly, the vessels around the tumor were quantified and CAM network topography analyzed. Tumor area in CAM that received LyeTxI-b showed a reduction similar to Cisplatin-treated, proven by histological analysis. Immunohistochemistry analysis showed the expression of hCDC47 in the CAM with colorectal tumor was lower after treatment with LyeTxI-b or Cisplatin. Also, LyeTxI-b or cisplatin treated CAM showed a significant reduction in area of vascularization in comparison to the vehicle-treated group. Using the CAM model it was possible to evaluate the efficacy of LyeTxI-b as a potent antitumor agent in CRC, quickly and effectively and in agreement to 3r's principle: to replace, reduce or refine the use of animals in experimentation.