DEVELOPMENT OF NOVEL MAGNETIC NANOTHERANOSTICS FOR THE COMBINATION THERAPY OF K-RAS DRIVEN NON SMALL CELL LUNG CANCER
Abstract
K-RAS is the most common mutated oncogene associated with Non-Small-Cell-Lung Cancer (NSCLC). So far there are no promising targeted therapies for the direct inhibition of KRAS and thus, considered to be undruggable. The standard course of treatment for patients with advanced NSCLC, often includes combined therapy using more than one therapeutic drugs. However, repeated failure of these therapies due to multi-drug resistance (MDR), poor bioavailability and severe side effects indicated the urgent need for effective targeted therapies. Towards this end, we have synthesized novel polyacrylic acid (PAA) coated iron oxide nanoparticles for multi parametric optical and MR imaging (MRI) and targeted treatment of K-RAS driven NSCLC. These magnetic nanoparticles (MNPs) were decorated with folate receptortargeting ligand, folic acid, using “Click” chemistry, in order to target NSCLC. In our design, we have introduced new polymeric platinum complex, 2-cyano-2-isonitroso- N morpholylacetamidoplatinum (II) (polymeric platinum complex, Pt(MCO)2,) potentially as an effective anti-cancer drug, when compared with cis-diaminodichloroplatinum (II) (cisplatin, CDDP). In addition, Hsp90 inhibitor, ((5Z)-5-(4-hydroxy-6-oxo-3-propan-2-ylcyclohexa-2,4-dien-1-ylidene)- 4-(1-methylindol-5-yl)-1,2,4-triazolidin-3-one) (ganetespib, GT) was used along with Pt(MCO)2 to evaluate the synergistic effect of combination therapy on NSCLC. Therefore, both these drugs and optical DiI dye were co-encapsulated within the PAA coating of MNPs using a modified solvent diffusion method. The resulting functional MNPs were purified using dialysis technique as well as using magnetic column and characterized using various spectroscopic methods. To evaluate the biocompatibility and therapeutic efficacy of these functional MNPs, various cell-based assays including (3-(4, 5-dimethyl-thiazol-2-yl)-2, 5 diphenyl tetrazolium bromide) MTT, apoptosis, and necrosis and ROS experiments were performed. Results showed minimal toxicity (less than 5% cell death) for functional MNPs with no therapeutic drug. This result indicated that our formulated functional MNPs are biocompatible. However, folate-decorated MNPs were able to target NSCLC and showed more than 70% cell death within 48 h of treatment, when single drug was encapsulated. Most importantly, more than 90% cells were dead when both drugs were carried. These results suggested that the importance of our newly formulated magnetic nano medicine and combination therapy. Apoptosis, necrosis, cell migration assays and microscopic experiments were performed to validate our results and to evaluate the observed therapeutic applications. Taken together, these studies demonstrate that the formulated new magnetic nanotheranostics are able
