Figure 1.

(A) Stages of Carcinogenesis. Initiation involves irreversibly alterations of particular tissue cells and increased susceptibility to tumor progression. The alterations are frequently related with mutational events induced with chemicals, radiation or biological agents (carcinogen). Promotion implicates the clonal expansion of altered cells leading to a visible tumor, a stage known to be reversible. In the progression stage, cells show several characteristic processes necessary to develop a malignant phenotype characterized by aggressive properties such as angiogenesis, cell proliferation and survival, immune evasion, cell migration and invasion, and metastasis. (B) Involvement of autophagy receptors in cancer progression. During the stage of cancer progression several characteristic processes occur. Angiogenesis corresponds to the formation of interconnected capillaries within the tumor. This is the product of the up-regulation and secretion of pro-angiogenic factors by cancer cells, a crucial process in the supply of oxygen and nutrients to the tumor. Cytosolic autophagy receptors do not promote this process. Cell proliferation and survival are the consequence of genetic changes which promotes metabolic and morphological features that sustain these events. P62, NBR1, NDP52, and OPTN are involved in the promotion of these processes by several mechanisms. Immune evasion corresponds to the mechanism by which cancer cells evaded the immune system, here represented by T cells. NBR1 is known to contribute to immune evasion. Migration and invasion processes are part of the metastatic cascade, in which cells acquire the capacity to migrate and invade the surrounding tissue of the primary tumor. Furthermore, it is proceeded by the intravasation into the circulatory or lymphatic system. p62 and NBR1 receptors promote migration and invasion processes. After intravasation, survival cells in circulation proceed to extravasation in a distant site (respect to primary tumor), and colonize and grow in a new site (metastasis colonization). p62 supports the metastatic process.