Provided herein are novel onco-fetal carbohydrate motifs present in adenocarcinoma cells. This novel carbohydrate motif is preferentially recognized by tomato fruit lectin-conotoxin. Also provided are methods for inhibiting proliferation and growth of cancer cells and for treating pathophysiological conditions, e.g., cancer, chronic pain, inflammation and/or a microbial infection, by contacting such cells with or administering tomato fruit lectin-conotoxin or similar natural or bioengineered molecules. In addition provided herein are genetically modified plants and seed, fruit, progeny, and hybrids therefrom and a genetically modified foodstuffs overexpressing a lectin-conotoxin. Further provided are DNA and expression vectors expressing lectin-conotoxin described herein.