Mechanical Properties of Breast Cancer Cell Membrane Studied with Optical Tweezers
GUO Hong-Lian1, LIU Chun-Xiang1, DUAN Jian-Fa2, Jiang Yu-Qiang1, HAN Xue-Hai2, LI Zhao-Lin1, CHENG Bing-Ying1, ZHANG Dao-Zhong1
1Optical Physics Laboratory, Institute of Physics, Chinese Academy of Sciences, Beijing 100080
2State Key Laboratory of Biomacromolecles, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101
Mechanical Properties of Breast Cancer Cell Membrane Studied with Optical Tweezers
1Optical Physics Laboratory, Institute of Physics, Chinese Academy of Sciences, Beijing 100080
2State Key Laboratory of Biomacromolecles, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101
Abstract： Membrane tethers are extracted from breast cancer cells using a force generated by an optical trap. It is experimentally obtained that the radius of tether is about 0.1μm and the static tether force is about
8.5 pN. Calculations based on the experimental measurements give a bending modulus for the tether of 1.35×10-19Nm and a surface membrane tension of 6.76×10-6N/m in the breast cancer
cell. The treatment with cytochalasin D results in the decreasing bending modulus and decreasing apparent surface tension. When the membrane protein caveolin is over-expressed, similar cases occur in bending modulus and apparent surface tension. In addition, the viscous resistance coefficient of the membrane is calculated to be 1.15pN.s/μm according to the dynamic tether forces obtained under different pulling velocities.
2004, Vol. 21 
