The use of magnetic nanorobots to activate chemotherapeutic prodrugs represents a promising alternative to current chemotherapeutic treatments. Here, a hybrid nanowire (NW) for targeted bioorthogonally driven activation of the latent chemotherapeutic prodrug 5‐fluoro‐1‐propargyl‐uracil (Pro‐5‐FU) in in vitro and in vivo cancer models is proposed. The NWs are composed of magnetic iron (Fe) and palladium (Pd), a known bioorthogonal catalyst. In vitro tests with a cancer cell line showed no significant cytotoxic effect by the NWs. In contrast, NWs combined with Pro‐5‐FU lead to a significant reduction of cell viability, similarly to the one induced by its active chemotherapeutic counterpart 5‐fluorouracil (5‐FU). The reduction in cell viability is attributed to the catalytic activation of Pro‐5‐FU into 5‐FU. To demonstrate their targeted therapeutic abilities, magnetic fields are used to attract the FePd NWs to a predefined area within a cultured cancer cell population, causing a local Pro‐5‐FU activation, and subsequent cell death in this region. As a proof of concept, NWs are injected in cancer tumor xenografts. The intraperitoneal injection of Pro‐5‐FU significantly retards tumour growth without causing significant side effects. This work presents a novel chemotherapeutic approach combining nanorobotics and bioorthogonal activation of prodrugs as an efficient alternative to conventional chemotherapy.

P-cadherin is frequently over-expressed in high-grade invasive breast carcinomas and has been reported to be an enhancer of migration and invasion of breast cancer cells, being correlated with tumour aggressiveness. In addition, expression of P-cadherin is well established as an indicator of poor prognosis in human breast cancer, which has stimulated our interest in studying its role in this setting. This review describes the most important findings on P-cadherin expression and function in normal mammary tissue and breast cancer cells, emphasizing that further research is required to elucidate the role played by this protein in human mammary tumours.

Epithelial-mesenchymal transition (also known as EMT) is a fundamental mechanism occurring during embryonic development and tissue differentiation, being also crucial for cancer progression. Actually, the EMT program contributes to the dissemination of cancer cells from solid tumors and to the formation of micro-metastasis that subsequently develop into clinically detectable metastases. Besides being a process that is defined by the progressive loss of epithelial cell characteristics and the acquisition of mesenchymal features, EMT has also been implicated in therapy resistance, immune escape and maintenance of cancer stem cell properties, such as self-renewal capacity. However, the majority of the studies usually neglect the progressive alterations occurring during intermediate EMT states, which imply a range of phenotypic cellular heterogeneity that can potentially generate more metastable and plastic tumor cells. In fact, few studies have tried to identify these transitory states, partly due to the current lack of a detailed understanding of EMT, as well as of reliable readouts for its progression. Herein, a brief review of evidences is presented, showing that P-cadherin expression, which has been already identified as a breast cancer stem cell marker and invasive promoter, is probably able to identify an intermediate EMT state associated with a metastable phenotype. This hypothesis is based on our own work, as well as on the results described by others, which suggest the use of P-cadherin as a promising EMT marker, clearly functioning as an important clinical prognostic factor and putative therapeutic target in breast carcinogenesis.