Primary Study On Myosin X Regulates Cell Migration

Cell migration is an essential characteristic of creature development. Myosin and actin are basic units of cytoskeleton which play a key role in cell migration. Myosin X is a member of myosin family. It exists in most of the vertebrate animals. Different expression of myosin X during rat brain development and neurons regeneration suggests that it probably participate in the development and regeneration of nervous system.Myosin X is existed in the edge of cultured cells. The interaction of matrix with cell surface will influence the cell migration speed. It was predicted that myosin X may be involved in cell migration. So, the myosin X expression was checked in different tumor cell lines. The results from the two stains of breast cancer cells suggested that under the condition of same actin level the myosin X was expressed differently according to the cell invasion ability. The MCF-7 cell is estrogen receptor positive and low-invasive cells showing lower myosin X expression while the MDA-MB231 cell is estrogen receptor negative and high-invasive cells showing higher myosin X expression. These results suggested that the content of myosin X in tumors was related to the cell migration speed. Then, the mRNA expression of myosin X was also detected in the above two cell lines with Real-time PCR. However, there was no similar tend which suggested myosin X expression was regulated at post-transcription level. It will be affirmed in vivo further.Besides, nervous system is a good model for researching on cell migration. To detect the role myosin X in neuron migration, the chicken embryos eletroporation in vivo system was set up. The plasmid of pCAGGS-IRES-EGFP-myosin X 86 was over-expressed in commissural neurons in chick embryonic neural tube by in ovo electroporation. The commissural axons over-expressing myosin X 86 failed to reach the contralateral ventral-horn region or to cross the midline. Furthermore, when myosin X siRNA was transfected into the chick embryonic neural tube, the neurons lost its original orientation. These results suggested that myosin X play a role in cell migration. The concrete mechanism will be investigated in future.