Regulation of Cell Motility Flashcards
What are the changes that occur in the cells that occur during tumour progression?
Genetic alterations lead to hyperproliferation, disassembly of cell-cell contacts, loss of polarity, increased motility and cleavage of ECM proteins
What are the different types of tumour cell migration?
Single cell migration (ameboid) Mesenchymal single cells Mesenchymal chains Clusters/cohorts Multicellular strands/sheets
What physiological phenomena does tumour migration mimic?
Morphogenesis e.g. angiogenesis
What did a comparison of the expression profile of invasive cells vs primary tumours show to be upregulated in invasive cells?
Cytoskeleton regulation
Motility machinery
What makes normal migrating cells stop moving?
Contact inhibition of locomotion
How are tumour cells different in this aspect?
They lose contact inhibition of locomotion so they can multilayer
What is another term for ECM proteins?
Substratum
What are filopodia?
Finger-like protrusions that are rich in actin filaments
They sense the local environment
What are lamellipodia?
Sheet-like protrusions that are rich in actin filaments
What are the four main stages of cell movement?
Extension
Adhesion
Translocation
De-adhesion
What are the attachments between the cell and the surface that it is moving along called?
Focal adhesions
What are the monomers of actin filaments?
G-actin
Describe the polarity of acting filaments.
They have a plus end and a minus end
The monomers preferentially get added on at the plus end
What protein complex is important in initiating polymerisation?
Arp2/3
This forms a trimer with actin and is good at initiating polymerisation
What is the limiting step in actin dynamics?
Formation of Arp2/3-actin trimers to initiate polymerisation