An Artificial Neural Network Model for Predicting the Subcellular Localization of Photosensitisers for Photodynamic Therapy of Solid Tumours
Photodynamic therapy (PDT) is a promising modality for the treatment of tumours based on the combined action of a photosensitiser (PS), visible light and molecular oxygen, which generates a local oxidative damage that leads to cell death. The site where the primary photodynamic effect takes place depends on the subcellular localization of the PS and affects the mode of action and efficacy of PDT. It is therefore of prime interest to develop structure-subcellular localization prediction models for a PS from its molecular structure and physicochemical properties. Here we describe such a prediction method for the localization of macrocyclic PSs into cell organelles based on a wide set of physicochemical properties and processed through an artificial neural network (ANN). 128 2Dmolecular descriptors related to lipophilicity/hydrophilicity, charge and structural features were calculated, then reduced to 76 by using Pearson’s correlation coefficient, and finally to 5 using Guyon and Elisseeff’s algorithm. The localization of 61 PSs was compiled from literature and distributed into 3 possible cell structures (mitochondria, lysosomes and “other organelles”). A non-linear ANN algorithm was used to process the information as a decision tree in order to solve PS-organelle assignment: first to identify PSs with mitochondrial and/or lysosomal localization from the rest, and to classify them in a second stage. This sequential ANN classification method has permitted to distinguish PSs located into two of the most important cell targets: lysosomes and mitochondria. The absence of false negatives in this assignation, combined with the rate of success in predicting PS localization in these organelles, permits the use of this ANN method to perform virtual screenings of drug candidates for PDT.
No Supplementary Data
Document Type: Research Article
Affiliations: Institut Quimic de Sarria, University Ramon Llull, Via Augusta 390, 08017 Barcelona, Spain.
Publication date: 2012-05-01
More about this publication?
- Current Medicinal Chemistry covers all the latest and outstanding developments in medicinal chemistry and rational drug design. Each issue contains a series of timely in-depth reviews written by leaders in the field covering a range of the current topics in medicinal chemistry. Current Medicinal Chemistry is an essential journal for every medicinal chemist who wishes to be kept informed and up-to-date with the latest and most important developments.