mitogenic

Mitogenic is an adjective describing substances, signals, or processes that stimulate cell division, specifically the entry of cells into mitosis by promoting progression through the cell cycle. In practice, mitogens are growth factors or cytokines that encourage cell proliferation in appropriate cell types and contexts.

Most mitogens exert their effects by binding to cell-surface receptors, such as receptor tyrosine kinases or cytokine receptors, and activating intracellular signaling cascades. Common pathways include the Ras–MAPK/ERK pathway, the PI3K–Akt pathway, and, in some cases, the JAK–STAT pathway. These signals converge to increase transcription of genes that drive the G1 to S phase transition, such as cyclins (notably cyclin D) and their associated CDKs, leading to DNA synthesis and cell division. The response is often context-dependent, varying with cell type, receptor expression, and the presence of other cues.

Examples of mitogens include epidermal growth factor (EGF), platelet-derived growth factor (PDGF), fibroblast growth factors (FGFs), insulin-like growth factor (IGF), and certain cytokines such as interleukin-2 (IL-2) that promote lymphocyte proliferation. Not all signals labeled as mitogenic produce division in every cell type; some may stimulate growth, differentiation, or other outcomes in different contexts.

Clinical and biological relevance encompasses roles in development, tissue maintenance, and wound healing, as well as implications in cancer, where constitutive mitogenic signaling can drive uncontrolled cell proliferation. Therapies often aim to modulate mitogenic pathways to control abnormal growth.