RT Journal Article SR Electronic T1 Differential Effects of Integrin αv Knockdown and Cilengitide on Sensitization of Triple-Negative Breast Cancer and Melanoma Cells to Microtubule Poisons JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 1334 OP 1351 DO 10.1124/mol.118.113027 VO 94 IS 6 A1 Nikolina Stojanović A1 Ana Dekanić A1 Mladen Paradžik A1 Dragomira Majhen A1 Krešimir Ferenčak A1 Jelena Ruščić A1 Irena Bardak A1 Christine Supina A1 Maja T. Tomicic A1 Markus Christmann A1 Maja Osmak A1 Andreja Ambriović-Ristov YR 2018 UL http://molpharm.aspetjournals.org/content/94/6/1334.abstract AB Low survival rates of patients with metastatic triple-negative breast cancer (TNBC) and melanoma, in which current therapies are ineffective, emphasize the need for new therapeutic approaches. Integrin β1 appears to be a promising target when combined with chemotherapy, but recent data have shown that its inactivation increases metastatic potential owing to the compensatory upregulation of other integrin subunits. Consequently, we analyzed the potential of integrin subunits αv, α3, or α4 as targets for improved therapy in seven TNBC and melanoma cell lines. Experiments performed in an integrin αvβ1-negative melanoma cell line, MDA-MB-435S, showed that knockdown of integrin subunit αv increased sensitivity to microtubule poisons vincristine or paclitaxel and decreased migration and invasion. In the MDA-MB-435S cell line, we also identified a phenomenon in which change in the expression of one integrin subunit changes the expression of other integrins, leading to an unpredictable influence on sensitivity to anticancer drugs and cell migration, referred to as the integrin switching effect. In a panel of six TNBCs and melanoma cell lines, the contribution of integrins αv versus integrins αvβ3/β5 was assessed by the combined action of αv-specific small interfering RNA or αvβ3/β5 inhibitor cilengitide with paclitaxel. Our results suggest that, for TNBC, knockdown of integrin αv in combination with paclitaxel presents a better therapeutic option than a combination of cilengitide with paclitaxel; however, in melanoma, neither of these combinations is advisable because a decreased sensitivity to paclitaxel was observed.