PHARMACOPHORE MODELLING FOR THE DISCOVERY OF SYSTEM XC- ANTIPORTER INHIBITORS

Cancer is one of the major disorders with increasing rates of morbidity and mortality. Recent drug discovery of anti cancer drug has identified several molecular targets and tried to achieve a goal of therapeutic effecative and safe molecule. Amongst these, system xc- antiporter is a novel promising target to control cancer progression. This antiporter is found to be over expressed in majority of cancer cells and functions by transporting amino acids, cystine and glutamate, in opposite directions. System xc- antiporter uptakes one molecule of cystine with the release of one molecule of glutamate in extracellular space. As already known cystine is precursor for the synthesis of glutathione, an in vivo antioxidant which is utilized by cancer cells to combat oxidative stress. At the other side the released glutamate (an excitatory neurotransmitter), when released in higher concentration, may over excite neurones (specifically and brain tumour) causing cell death to metastasise cancer cells. Therefore, through inhibition of system xc- antiporter, it is possible to kill cancer cells by disturbing their redox status along with through prevention of excitotoxcity by glutamate. In context to this, several researches have reported diverse molecules having system xc- antiporter inhibition potential. Amongst these molecules, erastin and its analogues are most potent system xc- antiporter inhibitors but it lacks preclinical data. Moreover, sulfasalazine, a FDA approved drug also showed good inhibition potential against this antiporter and therefore in our study we have attempted to construct pharmacophore model using this series to aid in the discovery of potent inhibitors with desirable safety. Results of this study exhibited successful development of pharmacophore model with phase survival score. Additionally, fit scores of sulfasalazine analogues were also in acceptable range. Hence, the developed pharmacophore model may be used for design of potent System xc- antiporter inhibitors