Nanoparticle Based Combination Treatments for Targeting Multiple Hallmarks of Cancer.

Treatment of cancer remains one of the most challenging tasks facing the healthcare system. Cancer affects the lives of millions of people and is often fatal. Current treatment methods include surgery, chemotherapy, radiation therapies or some combinations of these. However, recurrence is a major problem. These treatments can be invasive with severe side effects. Inefficacies in treatments are a result of the complex and variable biology of cancerous cells. Malignant tumor cells and normal functioning cells share many of the same biological characteristics but the main difference is that in cancer cells there is in an overuse and over expression of these biological characteristics. These pertinent characteristics can be grouped into eight hallmarks, as illustrated by Hanahan and Weinberg. These characteristics include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, activating invasion and metastasis, reprogramming energy metabolism, and evading immune destruction. In order to provide a noninvasive, effective treatment, delivery methods must be explored in order to transport cytotoxic agents used for targeting the hallmarks of cancer in a safer and more effective fashion. The use of nanoparticles as drug delivery carriers provides an effective method in which multiple cytotoxic agents can be safely delivered to cancer tissue to simultaneously target multiple hallmarks. By targeting multiple hallmarks of cancer at once, the efficacy of cancer treatments could be improved drastically. This review explores the uses and efficacy of combination therapies using nanoparticles that can simultaneously target multiple hallmarks of cancer.