Cytotoxicity of PEGylated liposomes co-loaded with novel pro-apoptotic drug NCL-240 and the MEK inhibitor cobimetinib against colon carcinoma in vitro.
The overactivation of signaling pathways, such as the PI3K and MAPK, which are crucial to cell growth and survival, is a common feature in many cancer types. Though a number of advances have been made in the development of molecular agents targeting these pathways, their application as monotherapies has not significantly improved clinical outcome. A novel liposomal preparation was developed, co-loaded with NCL-240, a small-molecule inhibitor of the PI3K/mTOR pathway, along with cobimetinib, a MEK/ERK pathway inhibitor. This combination drug-loaded nanocarrier, (N+C)-LP, was able to significantly enhance the cytotoxicity of these drugs against colon carcinoma cells in vitro demonstrating a clear synergistic effect (combination index of 0.79). The (N+C)-LP was also able to induce cell cycle arrest of the cells, specifically in the G1 phase thereby preventing their progression to the S-phase, typical of the action of MEK inhibitors. Analyzing the apoptotic events, it was found that this effect on cell cycle regulation is followed by the induction of apoptosis. The quantified distribution of apoptotic events showed that the (N+C)-LP induced apoptosis significantly by over 3-4 fold (P<0.001) compared to other treatment groups. The co-loaded liposomal preparation was also targeted to the transferrin receptor of cancer cells by modifying the surface of the liposome with transferrin. FACS analysis showed that transferrin-mediated targeting enhanced the association of liposomes to HCT 116 cells by almost 5-fold. This could potentially allow for cancer cell-specific effects in vivo thereby minimizing any non-specific interactions of the liposomes with non-cancerous cells. Taken together, this study clearly shows that the combined inhibition of the PI3K and MEK pathways correlates with a significant anti-proliferative effect, due to cell-cycle regulation leading to the induction of apoptosis.
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA.
Shravan Kumar
SK
Sriraman
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA; São Carlos Institute of Physics, University of São Paulo, São Carlos, SP 13566-590, Brazil.
Vananelia
V
Geraldo
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA.
Ed
E
Luther
Department of Biochemistry, Tufts University School of Medicine, Boston, MA 02111, USA.
Alexei
A
Degterev
Center for Pharmaceutical Biotechnology and Nanomedicine, Northeastern University, Boston, MA 02115, USA; Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia.
Vladimir
V
Torchilin
D017209:Apoptosis / Q000187:drug effects*; D001384:Azetidines / Q000008:administration & dosage* / Q000494:pharmacology; D002733:Chlorophenols / Q000008:administration & dosage* / Q000494:pharmacology; D003110:Colonic Neoplasms / Q000188:drug therapy*; D045325:HCT116 Cells; D006801:Humans; D008081:Liposomes; D020929:Mitogen-Activated Protein Kinase Kinases / Q000037:antagonists & inhibitors*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010880:Piperidines / Q000008:administration & dosage* / Q000494:pharmacology; D011092:Polyethylene Glycols / Q000737:chemistry; D047428:Protein Kinase Inhibitors / Q000008:administration & dosage*; D051057:Proto-Oncogene Proteins c-akt / Q000037:antagonists & inhibitors*; D014230:Triazoles / Q000008:administration & dosage* / Q000494:pharmacology
D001384:Azetidines; D002733:Chlorophenols; D008081:Liposomes; C000611383:NCL-240; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D014230:Triazoles; D011092:Polyethylene Glycols; D051057:Proto-Oncogene Proteins c-akt; D020929:Mitogen-Activated Protein Kinase Kinases; C574276:cobimetinib
Cobimetinib; Colon carcinoma; Liposomes; MEK; NCL-240; PI3K/AKT