Schematic representation of the biological process occurring during the cell cycle and the current understanding of the action of paclitaxel.
After the phase of growth and initial metabolic activity, the cell undergoes the phase of DNA replication and ulterior growth. Once maturity has been reached, the cell prepares for the mitotic process, which in physiological conditions would lead to cell division into two identical daughter cells. However, when the system is subjected to the anti-proliferative paclitaxel, the cell cycle is interrupted in the mitotic phase. The specific binding of paclitaxel molecules (CSB) to the intracellular microtubules determines their stabilization and impedes their reorganization essential for the cellular division. Part of the paclitaxel exchanged from the extracellular (CF) to the intracellular ambient (Ci) may remain unbound.