Research reported recently in ACS Nano explains a new method of targeting metastases in lymph nodes as a means of preventing the spread of cancers. The approach could provide novel treatment methods for patients vulnerable to metastasis, the process during which cancer cells separate from the primary tumor to form tumors at other sites. Metastasis is leading cause of cancer deaths.
This strategy targets lymph nodes because metastatic cancer usually spreads first to these glands through small vessels called lymphatics, which carry immune cells and fluid. While most conventional treatment options utilize biopsies of the lymph nodes to see if metastasis has occurred, taking a biopsy is an invasive procedure that can cause pain and infection. Instead of biopsies, the method developed by researchers Hong-Jun Li, Jin-Zhi Du and colleagues uses a nanoparticle delivery tool, called iCluster.
iCluster is already used as a nanoparticle delivery tool to bring chemotherapies directly to tumors, but by injecting iCluster combined with a red dye into mice with tumors, the researchers figured out that iCluster is also capable of entering a tumor and passing through the lymphatics. Using fluorescent imaging, the scientists saw that this mechanism provides a channel to target the lymph nodes directly and potentially treat metastases.
The study concluded that 40% of the treated mice treated with iCluster were still alive 110 days following the removal of the tumor; in comparison, those mice that did not receive treatment from iCluster before the removal of tumors all died from metastases within 51 days of surgery. Additionally, while the iCluster-treated mice lived longer, they also were seen to have far fewer tumors than untreated mice.
The authors explain their findings, stating, “Here, we uncovered that improved perfusion in a primary tumor facilitates nanoparticle translocation to lymph nodes for inhibiting tumor metastasis. On the basis of our finding that an iCluster platform…markedly improved particle perfusion in the interstitium of the primary tumor, we further revealed in the current study that such tumor-specific size transition promoted particle intravasation into tumor lymphatics and migration into lymph nodes.”