Tubulin polymerization/P-gp-IN-1 is a dual inhibitor targeting both tubulin polymerization and P-gp. It disrupts tubulin polymerization, inducing G2/M phase arrest and apoptosis (apoptosis). By inhibiting P-gp's efflux function, it reverses multidrug resistance (MDR). Tubulin polymerization/P-gp-IN-1 has dual roles: direct antitumor activity and reversal of P-gp-mediated cisplatin resistance. It binds stably to the tubulin CBS domain (ΔG = −12.4 kcal/mol) and the P-gp hydrophobic cavity (ΔG = −10.8 kcal/mol). Tubulin polymerization/P-gp-IN-1 is applicable for research on drug-resistant cervical cancer.

Tubulin polymerization/P-gp-IN-1 (Compound 6h) demonstrates high efficacy against sensitive cell lines such as HeLa (IC50 = 6.69 μM), CaSki (IC50 = 7.84 μM), and SiHa (IC50 = 16.68 μM), and retains similar effectiveness against the resistant HeLa/DDP cell line (IC50 = 7.21 μM), while exhibiting minimal cytotoxicity towards normal human cervical cells (IC50 = 51.95 μM). At concentrations of 4-16 μM over 24 hours, it reduces levels of polymerized α- and β-tubulins while increasing depolymerized tubulin levels, akin to colchicine (COL) but opposite to paclitaxel (PTX), resulting in microtubule network contraction, especially at 8 μM and 16 μM, causing a change in cell morphology from spindle-shaped to rounded, with microtubules localized to the perinuclear region in HeLa and HeLa/DDP cells. Furthermore, Tubulin polymerization/P-gp-IN-1 (4-16 μM, 24 hours) induces G2/M phase cell cycle arrest and effectively triggers apoptosis and significantly inhibits migration in HeLa and HeLa/DDP cells in a concentration-dependent manner. This compound (0.25, 0.5, 1 μM, 48 hours) effectively reverses cisplatin resistance in HeLa/DDP cells. Additionally, at 0.25, 0.5, 1 μM for 12 hours, it inhibits P-gp-mediated efflux in a concentration-dependent manner and maintains P-gp protein levels at 1 μM in HeLa/DDP cells, significantly stabilizing P-gp at high temperatures of 61°C.

Tubulin polymerization/P-gp-IN-1 (Compound 6h) is exceptionally safe even at concentrations up to 400 μM over 96 hours in zebrafish embryos, exhibiting a 0% mortality rate and an 8.3% malformation rate.