Combining nanoliposomal ceramide with sorafenib synergistically inhibits melanoma and breast cancer cell survival to decrease tumor development.
OBJECTIVE
Deregulation of phosphatidylinositol 3-kinase/Akt and Ras/Raf/mitogen-activated protein kinase/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase pathways occurs in melanoma and breast cancer, deregulating normal cellular apoptosis and proliferation. Therapeutic cocktails simultaneously targeting these pathways could promote synergistically acting tumor inhibition. However, agents with manageable toxicity and mechanistic basis for synergy need identification. The purpose of this study is to evaluate the preclinical therapeutic efficacy and associated toxicity of combining sorafenib with nanoliposomal ceramide.


METHODS
Effects of sorafenib and nanoliposomal ceramide as single and combinatorial agents were examined on cultured cells using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium salt assays and CalcuSyn software used to assess synergistic or additive inhibition. Western blotting measured cooperative effects on signaling pathways. Rates of proliferation, apoptosis, and angiogenesis were measured in size- and time-matched tumors to identify mechanistic basis for inhibition. Toxicity was evaluated measuring animal weight, blood toxicity parameters, and changes in liver histology.


RESULTS
Sorafenib and nanoliposomal ceramide synergistically inhibited cultured cells by cooperatively targeting mitogen-activated protein kinase and phosphatidylinositol 3-kinase signaling. A 1- to 2-fold increase in cellular apoptosis and 3- to 4-fold decrease in cellular proliferation were observed following combination treatment compared with single agents, which caused synergistically acting inhibition. In vivo, an approximately 30% increase in tumor inhibition compared with sorafenib treatment alone and an approximately 58% reduction in tumor size compared with nanoliposomal ceramide monotherapy occurred by doubling apoptosis rates with negligible systemic toxicity.


CONCLUSIONS
This study shows that nanoliposomal ceramide enhances effectiveness of sorafenib causing synergistic inhibition. Thus, a foundation is established for clinical trials evaluating the efficacy of combining sorafenib with nanoliposomal ceramide for treatment of cancers.
Department of Pharmacology-R130, Pennsylvania State University College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
Melissa A
MA
Tran
Charles D
CD
Smith
Mark
M
Kester
Gavin P
GP
Robertson
D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage* / Q000009:adverse effects; D017209:Apoptosis / Q000187:drug effects; D001557:Benzenesulfonates / Q000008:administration & dosage* / Q000009:adverse effects; D015153:Blotting, Western; D001943:Breast Neoplasms / Q000188:drug therapy*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002518:Ceramides / Q000008:administration & dosage*; D004357:Drug Synergism; D006801:Humans; D008081:Liposomes; D008545:Melanoma / Q000188:drug therapy*; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects; D053758:Nanoparticles; D009389:Neovascularization, Pathologic / Q000188:drug therapy; D009536:Niacinamide / Q000031:analogs & derivatives; D010671:Phenylurea Compounds; D051057:Proto-Oncogene Proteins c-akt / Q000187:drug effects; D011725:Pyridines / Q000008:administration & dosage* / Q000009:adverse effects; D015398:Signal Transduction / Q000187:drug effects; D000077157:Sorafenib
D001557:Benzenesulfonates; D002518:Ceramides; D008081:Liposomes; D010671:Phenylurea Compounds; D011725:Pyridines; D009536:Niacinamide; D000077157:Sorafenib; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases