Effects of quantum dots on integrin expression and cellular responses in DU145 prostate cancer cells

Quantum dots (QDs) are extensively investigated for biomedical applications, including cancer diagnostics and therapy; however, their potential subcytotoxic effects on cancer cell behavior remain incompletely understood. The aim of this study was to assess whether exposure to QDs at non-cytotoxic concentrations (0.1-10 μg/mL) modulates the expression of selected integrins and alters adhesion-related functional properties of DU-145 prostate cancer cells. Cytotoxicity was evaluated using sulforhodamine B, neutral red, and resazurin assays. Changes in integrin expression were analyzed at the mRNA level by qRT-PCR and at the protein level using integrin-mediated cell adhesion arrays and ELISA. Functional effects were assessed using collagen adhesion, scratch migration, and extracellular matrix-based invasion assays. QDs exhibited low cytotoxicity toward DU-145 cells across the tested concentration range. Despite the absence of pronounced cytotoxic effects, QDs induced selective, concentration- and time-dependent modulation of integrin expression, including increased levels of the αvβ3 heterodimer and the β1 subunit at both the transcriptional and protein levels. Functionally, QDs exposure resulted in a modest but significant increase in cell adhesion and invasion, while cell migration remained unaffected. These findings indicate that QDs can elicit sublethal alterations in adhesion-related pathways without overt cytotoxicity, highlighting the importance of considering integrinmediated effects in the in vitro safety assessment of nanomaterials intended for biomedical use.