Local and transient gene expression primes the liver to resist cancer metastasis
A l'aide de modèles murins de cancer du côlon-rectum ou du sein formant des métastases hépatiques, cette étude met en évidence l'intérêt de nanoparticules qui, en piégeant spécifiquement la chimiokine CXCL12 dans les hépatocytes du foie, inhibent le processus métastatique
The liver is a common site of metastasis for colorectal cancer and other tumor types, and tumors that have spread to the liver are much more difficult to treat than those that remain localized. To address this problem, Goodwin et al. took advantage of the CXCL12 chemokine signaling pathway that helps cancer cells take up residence in the liver. This pathway’s role in metastasis is already known, but earlier therapies that tried to inhibit CXCL12 throughout the body were too toxic for clinical use. Here, the authors designed a targeted nanoparticle that homes to the liver and specifically traps CXCL12, thereby preventing the establishment of liver metastasis in mouse models of colorectal and breast cancers. The liver is the primary site of metastasis for gastrointestinal cancers and is a location highly susceptible to the establishment of metastasis in numerous other primary cancers, including breast, lung, and pancreatic cancers. The current standard of care typically consists of primary tumor resection and systemic administration of potent but toxic chemotherapeutics, yielding a minimal improvement in the median survival rate. CXCL12, a chemokine, is a key factor for activating the migration/survival pathways of CXCR4+ cancer cells and for recruiting immunosuppressive cells to areas of inflammation. Therefore, reducing CXCL12 concentrations within the liver has the potential to decrease tumor and immunosuppressive cell activation/migration within the liver. However, because of off-target toxicities associated with systemic administration of anti-CXCL12 therapies, transient and liver-specific expression of a CXCL12 trap is necessary. To address this challenge, we developed a lipid calcium phosphate nanoparticle optimized for delivering plasmid DNA, encoding an engineered CXCL12 protein trap, to the nucleus of liver hepatocytes. This pCXCL12-trap formulation yielded transient (4 days) liver-specific expression, which greatly decreased the occurrence of liver metastasis in two aggressive liver metastasis models, including colorectal [CT-26(FL3)] and breast (4T1) cancers. Subsequent studies in an aggressive human colorectal liver metastasis model (HT-29) decreased the establishment of liver metastasis more effectively than did systemic administration of the CXCL12 protein trap and to a level comparable to a high-dose regimen of a potent CXCR4 antagonist (AMD3100).