*3.7. Cell Culture*

All cell lines used in this investigation were purchased from ATCC.

The neuroblastoma cell line Neuro-2a and the human breast cancer cell line MCF-7 were cultured in DMEM medium containing 10% fetal bovine serum (Biolot, St. Petersburg, Russia) and 1% penicillin/streptomycin (Invitrogen, Carlsbad, CA, USA).

The human prostate cancer cell line 22Rv1 was cultured according to the manufacturer's instructions in 10% FBS/RPMI medium (Invitrogen). Cells were continuously kept in culture for a maximum of 3 months, were routinely inspected microscopically for stable phenotype, and regularly checked for contamination with mycoplasma. Cell line authentication was performed by DSMZ (Braunschweig, Germany) using highly polymorphic short tandem repeat loci [22].

All cells were incubated at 37 ◦C in a humidified atmosphere containing 5% (*v*/*v*) CO2.
