DL-Methadone as an Enhancer of Chemotherapeutic Drugs in Head and Neck Cancer Cell Lines.

BACKGROUND/AIM: The aim of this study was to analyze the effect of DL-methadone on enhancing the action of the chemotherapeutic drugs cisplatin, doxorubicin, 5-fluoruracil (5-FU) and paclitaxel on head and neck squamous carcinoma (HNSCC) cell lines. MATERIALS AND METHODS: The chemotherapeutic drugs were applied alone or in combination with DL-methadone and cytotoxicity was analyzed by XTT assays. Expression of the µ-opioid receptor and the drug transporter p-glycoprotein were analyzed by qRT-PCR. RESULTS: The effect of DL-methadone strongly depended on the respective chemotherapeutic agent. The basic expression of the µ-opioid receptor was not associated with the effect of DL-methadone, rather its induction by chemotherapeutic drugs. Expression or expression induction of p-glycoprotein was higher in weak-responder cell lines. CONCLUSION: Enhancement of the toxicity of chemotherapeutic drugs by DL-methadone depends on the drug and on the cell line used.

Stem cell labeling with iron oxide nanoparticles: impact of 3D culture on cell labeling maintenance.

AIM: We aimed to analyze the suitability of nanoparticles (M4E) for safe human mesenchymal stem cell (hMSC) labeling and determined cell labeling maintenance in 2D and 3D culture. MATERIALS & METHODS: We investigated cell-particle interaction and the particles' impact on cell viability, growth and proliferation. We analyzed cell labeling maintenance in 2D and 3D culture invasively and noninvasively. RESULTS: M4E do not affect cell viability, growth and proliferation and do not cause chromosomal aberrations. Cell labeling maintenance is up to five-times higher in 3D conditions compared with 2D culture. CONCLUSION: M4E allow safe hMSC labeling and noninvasive identification. Our hMSC-loaded, 3D tissue-engineered construct could serve as a graft for regenerative therapies, in which M4E-labeled hMSCs can migrate to their target.