Different fate of cancer cells on several chemical functional groups

Self-assembled monolayers with different terminal chemical groups including thiol (-SH), methyl (-CH3), carboxyl (-COOH) and hydroxyl (-OH) were employed as substrates for the culture of hepatoma cells (HepG2s). X-ray photoelectron spectroscopy and atomic force microscopy confirmed the similar density of different functional groups occupation. The adhesion and proliferation of cancer cells exhibited significant difference on different surfaces. The HepG2s adhered to -CH3 surfaces but exhibited the smallest contact area with mostly rounded morphology, while those on -SH surfaces exhibited the largest contact area with extensive spreading. The proliferation of HepG2s in prolonged culture was significantly inhibited on -CH3 surface. Cells on other surfaces of various chemical groups proliferated at different levels. After 7 days of culture, the proliferation of HepG2s on the different surfaces followed the trend: -OH approximate to -COOH > -SH >> -CH3. Due to the strong hydrophobic property, the -CH3 group inhibited the cell adhesion, which led to the death of cancer cells. Compared with other chemical functional groups, the -CH3 group exhibited its unique effect on the fate of cancer cells, providing a potential way on prevention and treatment of liver cancer. (C) 2012 Elsevier B.V. All rights reserved.