Discovery of antitumor lectins from rainforest tree root transcriptomes
(A) Cytotoxicity profile of ML6 towards a panel of mucosal (red) and non-mucosal (blue) cancer cell lines, as well as non-cancerous healthy cells (green) as controls. Curves were fit using a non-linear regression analysis to calculate IC50 values (see Table 1). (B) Brightfield micrographs of ML6-sensitive A549 (top) or the ML6-insensitive MCF-7 (bottom) cell line before (U) and after (T) treatment for 24 hours in the presence of 1nM lectin. Scale bar = 100 μm. (C) Representative toxicity curves comparing the anticancer activity of ML6 (red) to the standard chemotherapeutics Ptx (grey) and Dox (black) in A549 cells. Dashed line represents the IC50. (D) Representative scatter plots from flow cytometric PI/Annexin V-FITC apoptosis assays. ML6-sensitive A549 cells line were treated with 1 pM of ML6 for 1 or 14 hours before analysis. (E) Quadrant quantification of flow cytometry data defining the healthy cell population from those in early and late apoptosis, or necrosis, as a function of lectin incubation time.