Lung cancer stem cells - the role in pathogenesis and progressive growth of cancer

Lung cancer is the main cause of cancer death worldwide. Rapid accurate diagnosis, recognition of risk factors and improvement of treatment efficacy represent the main challenges. An advanced stage of the disease at the time of diagnosis, observed in the majority of cases, makes the introduction of radical treatment impossible or ineffective. Immunotherapy was a breakthrough in achieving long-term survival in recent years. The reason for developing this type of treatment is to know the interaction between the host cells and tumor cells. Cancer stem cells theory is increasingly gaining greater significance in the world. The biological heterogeneity of lung cancer may be due to the presence of a small percentage of cancer stem cells (CSCs). CSCs are the results of genetic and epigenetic changes in normal stem cells, progenitor cells or differentiated cells. CSCs are functionally defined by their unlimited self-renewal capacity, multiple differentiation and their ability to imitate tumors. It is believed that CSCs determine unrestricted growth of tumors and their different morphology. Their ability to self-renew can be the cause of relapses even after long periods of remission. CSCs reside in niches, where they receive signals for differentiation and proliferation process. The identification of CSCs is based on the presence of specific molecules (CD133, CD44, CD90, ALDH, EpCAM). An important feature of CSCs is their resistance to conventional cancer treatment: radio therapy and chemotherapy. Presumably, CSCs are responsible for the synthesis of immunosuppressive particles, and recruiting other molecules, which have immunosuppressive properties. The paper presents the current state of knowledge on CSCs in lung cancer detailing adenocarcinoma.