The question of whether cancer stem cells are a type of specialized cell has many answers. The current concept of cancer stem cells is based on the idea that a small population of tumoral cells has stem-like characteristics that supports tumor growth. This view is undergoing revision and some studies are encouraging a more radical rethink. Cancer stem cells are currently considered to be primarily cancer-associated cells that exhibit increased epigenetic plasticity and gene expression variability.
Recent studies show that cancer stem cells may be responsible for the regrowth of breast tumors following chemotherapy. Chemotherapy-induced regrowth of cancer stem cells is one of the primary reasons why breast tumors become drug resistant. The benefits of chemo treatment are only temporary and the recurrence of cancer is often fatal. Thankfully, recent studies have shown that cancer death rates are decreasing, but this trend is not universal.
CSCs are dynamic cells that have undergone numerous transformations. These changes reflect their active role in the progression of tumours. Furthermore, CSCs are capable of changing their behaviour in response to their microenvironment, which can lead to more effective therapeutic strategies. This research should help cancer patients understand what differentiates CSCs from normal stem cells. It is also important to note that CSCs have distinct roles in the progression of cancer.
Recent studies suggest that cancer stem cells represent a small subpopulation of cells within a tumor. Their characteristics include self-renewal and differentiation capacity, as well as the ability to regenerate a tumor in a host animal. They also play important roles in metastasis. They are particularly resistant to conventional treatments, such as chemotherapy and radiation. So, the discovery of new drugs aimed at cancer stem cells is important.
Although the origin of cancer stem cells is still a hot topic, there is no consensus on which cell type is the source of tumor-specific CSCs. The answer to this question depends on the phenotype and type of tumor. As of now, the only way to demonstrate the origin of cancer stem cells is by identifying a tumor’s “cell of origin”. Several alternative theories have been proposed, including the possibility of embryonic rests, alterations in gene expression, and unidentified origins of cancer stem cells.
The emergence of cancer stem cells is closely related to tumour inflammation. Inflammation is a known cause of cancer initiation. The transition of stem cells into cancer stem cells is preceded by the formation of a niche that harbors high levels of ROS, LPPs, and inflammatory cytokines. These toxins damage stem cells’ DNA. This in turn promotes mutations that lead to cancer. If a tumour is unable to regenerate stem cells, the cancer will continue to spread and recur.
One key difference between cancer stem cells and normal tumor cells is their resistance to chemotherapy. Cancer stem cells are highly resistant to chemotherapy because they express high levels of specific drug transporters that actively efflux drugs from the cell and protect the cancer cells from cytotoxic agents. There are a variety of mechanisms by which cancer cells acquire resistance to chemotherapy, such as inactivation of drug receptors or elimination of the cell. This resistance is a major obstacle for developing effective cancer treatments.
