Evaluation of doxycycline functionalized AuNPs as a mitochondria-targeted therapy for melanoma resistant cells

CAMMARATA A.; ATIA M.; GLISONI R.J.; DURAN H.; TAVERNA PORRO M.

BUENOS AIRES

Congreso; Annual Meeting of Bioscience Societies 2021; 2021

SAIC-SAI-AAFE-NANOMED

Melanoma, the most lethal form of skin cancer, is a highly aggressive tumor whose incidence is increasing. Cancer stem cells (CSCs) are responsible not only for the tumor initiation, but also for its progression and recurrence. CSCs are quiescent cells that overexpress mitochondrial related proteins, thus disruption of mitochondrial activity may represent a new approach for the elimination of CSCs. Nanotechnology improves cancer therapy and reduces its adverse effects by specifically delivering drugs to tumor tissues. In this work we present a nanotechnology strategy for targetingCSCs, using gold nanoparticles (AuNPs) conjugated with doxycycline (DOXY), an inhibitor of mitochondrial biogenesis. Initially, the in vitro effects of free DOXY were studied using radiosensitive (A375) and radioresistant (A375-G10 and Mel-J) melanoma cell lines. All cell lines displayed a significant reduction on cell viability and metabolic activity at concentrations above 25 µM of DOXY, being the radioresistant cells more affected. Also, radiosensitization was evaluated by clonogenic assays in A375- G10 cells irradiated with a gamma rays source (137Cs). At 1 Gy survival fraction was reduced from 60% on control to 28% on those pre-treated with DOXY. We propose different strategies to produce the nanoconjugates. Firstly, DOXY- AuNPs were synthesized using DOXY as a reducer and stabilizer agent in alkaline conditions. Secondly, AuNPs were obtained by a traditional Turkevich method, and a polymer-DOXY conjugate was attached. Hydrodynamic diameter measured by DLS was 15 nm for DOXY-AuNPs and 36 nm for traditional synthesized AuNPs, with a strong absorption band by UV-Visible spectroscopy at 520 nm and 525 nm, respectively. We are currently working on determining the effects of these nanosystems on proliferative activity and clonogenic capacity of the cell lines. These preliminary results suggest the possibility of controlling melanoma resistant cells using a mitochondria targeted therapy.