Journal of Cancer Research and Immuno-Oncology
Open Access

Immunotherapy and Targeted Therapies for Cancer Stem Cells: New Approaches to Cancer Treatment

Andrea Graham^{* *}Correspondence: Andrea Graham, Department of Cancer Evolutionary Genomics, Queen Mary University, London, UK, Email:

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Description

Cancer stem cells are a subset of cells within a tumor that have the ability to self-renew and differentiate into different cell types that make up the bulk of the tumor. They are believed to be the driving force behind tumor initiation, progression, and metastasis. While conventional cancer therapies such as chemotherapy and radiation can reduce the size of tumors by killing the bulk of cancer cells, cancer stem cells are often resistant to these treatments and can give rise to new tumors, leading to disease relapse. Cancer stem cells were first identified in leukemia in the 1990s, and since then, researchers have discovered their presence in a wide range of solid tumors, including breast, colon, brain, and prostate cancers. These cells are characterized by the expression of specific markers, such as CD133, CD44, and ALDH1, among others. However, the specific markers and characteristics of cancer stem cells can vary depending on the tumor type and the microenvironment in which they are found.

One of the key characteristics of cancer stem cells is their ability to self-renew. This means that they can divide indefinitely and produce more cancer stem cells. This property is critical for tumor initiation, as it allows a single cancer stem cell to give rise to a whole tumor. Additionally, cancer stem cells can differentiate into different types of cells within the tumor, including non-stem cancer cells, which make up the bulk of the tumor. This process is regulated by complex signaling pathways, including those involving Wnt, Notch, and Hedgehog. Cancer stem cells are also thought to be responsible for tumor heterogeneity, which is the observation that tumors can be made up of cells with different genetic and phenotypic characteristics. This heterogeneity can make it difficult to develop effective therapies, as different cells within the tumor may respond differently to treatment. For example, some cancer stem cells may be resistant to chemotherapy or radiation, while others may be sensitive to these treatments. The role of cancer stem cells in tumor progression and metastasis is also an area of active research. It is believed that cancer stem cells may be responsible for the initiation of metastasis by breaking away from the primary tumor and traveling to other parts of the body. Additionally, cancer stem cells may play a role in the formation of new blood vessels, which is critical for tumor growth and metastasis.

Given their importance in cancer initiation, progression, and metastasis, cancer stem cells are an attractive target for cancer therapies. However, targeting these cells is challenging, as they are often resistant to conventional treatments. Additionally, targeting cancer stem cells may require the development of new drugs that specifically target the unique properties of these cells, such as their self-renewal ability or their interactions with the tumor microenvironment. One potential approach to targeting cancer stem cells is the use of targeted therapies that specifically inhibit signaling pathways involved in self-renewal and differentiation. For example, inhibitors of the Wnt signaling pathway have shown promise in preclinical studies of breast cancer stem cells. Additionally, drugs that disrupt the interaction between cancer stem cells and the tumor microenvironment may also be effective in targeting these cells.

Another approach to targeting cancer stem cells is the use of immunotherapy. The immune system plays an important role in detecting and eliminating cancer cells, and there is evidence to suggest that cancer stem cells may be more susceptible to immune-mediated destruction than non-stem cancer cells. One strategy for targeting cancer stem cells with immunotherapy is the use of vaccines that target cancer stem cell-specific antigens.

Another approach is the use of Chimeric Antigen Receptor (CAR) T cells, which are engineered immune cells that can recognize and kill cancer cells and cancer stem cells are a subset of cells within a tumor that have the ability to self-renew and differentiate into different cell types.