Nanomedicine‐Based Immunotherapy for the Treatment of Cancer Metastasis

Abstract

Metastasis is the leading cause of cancer‐associated death, with poor prognosis even after extensive treatment. The dormancy of metastatic cancer cells during dissemination or after colony formation is one major reason for treatment failure, as most drugs target cells of active proliferation. Immunotherapy has shown great potential in cancer therapy because the activity of effector cells is less affected by the metabolic status of cancer cells. In addition, metastatic cells out of immunosuppressive tumor microenvironment (TME) are more susceptible to immune clearance, although these cells can achieve immune surveillance evasion via strategies such as platelet and macrophage recruitment. Since nanomaterials themselves or their carried drugs have the capability to modulate the immune system, a great amount of focus has been placed on nanomedicine strategies that leverage immune cells participating the metastatic cascade. These nanomedicines successfully inhibit the tumor metastasis and prolong the survival of model animals. Immune cells that are involved in the metastasis cascade are first summarized and then recent and inspiring strategies and nanomaterials in this growing field are highlighted.

Engineering Prodrug Nanomedicine for Cancer Immunotherapy

“…Compared with the conventional therapeutic modalities including chemotherapy, surgical resection, and radiotherapy for can-cer treatment, immunotherapy works by activating immune cells and producing memory T cells to regress tumor growth, and immunotherapy has obvious advantages in inhibiting tumor reoccurrence and metastasis. [172] However, there are several shortcomings of current cancer immunotherapy, including low immune responses, poor tumor targeting, and severe side effects of the immunotherapeutics. [173] Prodrug nanomedicines integrate the advantages of prodrugs and nanotechnology to enhance the efficiency and safety of tumor immunotherapy relative to the conventional nanomedicine.…”

<p>Nanomaterial-Based Tumor Photothermal Immunotherapy</p>

“…It was noticed that over 80% of patients diagnosed with lung cancer present with metastatic disease. [2][3][4][5][6] Chemotherapy, hormonal therapy and radiation therapy serve palliative purposes in the metastatic cancers and offer a modest extension of survival. However, the therapeutic effect is still unsatisfactory.…”

Discovery of core gene families associated with liver metastasis in colorectal cancer and regulatory roles in tumor cell immune infiltration

“…The resistance of metastatic cancer could be attributed to its partial dormancy, which confers resistance to the conventional therapy aimed at suppressing proliferation [16] . Encouragingly, cancer immunotherapy has emerged as a promising anti-cancer strategy, whereby aberrant cells can be obliterated, irrespective of their activation status [16] . This novel therapy has brought significant benefits in liver metastasis [17] .…”