Molecules, Vol. 25, Pages 2562: Transiently Expressed Mistletoe Lectin II in Nicotiana benthamiana Demonstrates Anticancer Activity In Vitro

Molecules, Vol. 25, Pages 2562: Transiently Expressed Mistletoe Lectin II in Nicotiana benthamiana Demonstrates Anticancer Activity In Vitro Molecules doi: 10.3390/molecules25112562 Authors: Milena Mazalovska J. Calvin Kouokam Mistletoe (Viscum album) extracts have been used as alternative and complementary therapeutic preparations in multiple cancers for decades. Mistletoe lectins (ML-I, ML-II, and ML-III) are considered to be the main anticancer components of such preparations. In the present study, ML-II was transiently expressed in Nicotiana benthamiana using the pEAQ-HT expression system. Expression levels of up to 60 mg/kg of the infiltrated plant tissue were obtained, and a three-fold increase was achieved by adding the endoplasmic reticulum (ER) retention signal KDEL to the native ML-II sequence. The native protein containing His-tag and KDEL was purified by immobilized metal affinity chromatography (IMAC) and gel filtration. We found that the recombinant ML-II lectin was glycosylated and retained its carbohydrate-binding activity. In addition, we demonstrated that plant produced ML-II displayed anticancer activity in vitro, inhibiting non-small cell lung cancer H460 and A549 cells with EC50 values of 4 and 3.5 µg/mL, respectively. Annexin V-448A and PI double staining revealed that cell cytotoxicity occurred via apoptosis induction. These results indicate that ML-II transiently expressed in N. benthamiana plants is a promising candidate as an ...
Source: Molecules - Category: Chemistry Authors: Tags: Article Source Type: research