http://www.haematologica.org/content/early/2019/06/25/haematol.2018.211490.article-info
Abstract
One-third of diffuse large B-cell lymphoma patients are refractory to initial treatment or relapse after rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone chemotherapy. In these patients, CXCR4 overexpression (CXCR4+) associates with lower overall and disease-free survival. Nanomedicine pursues active targeting to selectively deliver antitumor agents to cancer cells, a novel approach that promises to revolutionize therapy by dramatically increasing drug concentration in target tumor cells. In this study, we intravenously administered a liganded protein nanocarrier (T22-GFP-H6) targeting CXCR4+ lymphoma cells in mouse models to assess its selectivity as a nanocarrier, by measuring its tissue biodistribution in cancer and normal cells. No previous protein-based nanocarrier has been described to specifically target lymphoma cells. T22-GFP-H6 achieved a highly selective tumor uptake in a CXCR4+ lymphoma subcutaneous model, as detected by fluorescent emission. We demonstrated that tumor uptake was CXCR4-dependent because pretreatment with AMD3100, a CXCR4 antagonist, significantly reduced tumor uptake. Moreover, in contrast to CXCR4+ subcutaneous models, CXCR4- tumors did not accumulate the nanocarrier. Most importantly, after intravenous injection in a disseminated model, the nanocarrier accumulated and internalized in all clinically relevant organs affected by lymphoma cells, with negligible distribution to unaffected tissues. Finally, we obtained antitumor effect without toxicity in a CXCR4+ lymphoma model by T22-DITOX-H6 administration, a nanoparticle incorporating a toxin with the same structure as the nanocarrier. Hence, the use of T22-GFP-H6 nanocarrier could be a good strategy to load and deliver drugs or toxins to treat specifically CXCR4-mediated refractory or relapsed diffuse large B-cell lymphoma without systemic toxicity.