Measuring the nano-mechanical properties of normal and cancerous prostate cells using atomic force microscopy

Prostate cancer is one of the most common malignant tumors threatening male health. The important reason for high mortality rate of prostate cancer is the difficulty in early diagnosis. The nano-mechanical property of cells has been used as a useful index for early cancer diagnosis at single cell level. In this study, atomic force microscopy (AFM) was implemented to measure and compare the morphology and elasticity of different prostate cell lines, including normal cells (PZ-HPV-7) and cancer cells (PC-3). The results showed that the morphology of PZ-HPV-7 cell has a multiple-angle or other irregular shape and the cellular surface is smooth with fewer protrusions. While PC-3 cell has a spindle or spherical shape with more protrusions on the membrane. The average values of elasticity of PZ-HPV-7 and PC-3 cells were 2206.85 +/- 1084.99 Pa and 1226.19 +/- 520.36 Pa, respectively. And the average values of viscosity were 20.21 +/- 4.96 Pa.s and 13.24 +/- 4.52 Pa.s, respectively. We found that the elasticity and viscosity of PC-3 were significantly lower than those of PZ-HPV-7, suggesting that the prostate cancer cells are softer than the normal counterpart. It shows that the nano-mechanical properties of cells may provide an early index at single cell level for prostate cancer early detection.