It seems pretty insignificant to say that cells can move and change shapes, yet it is crucial to our development. As embryos, stem cells start to divide and differentiate rapidly. Cells begin to form, move, and change shapes to make all of our organs. Additionally, human macrophages use their shape to kill antigens through the process of phagocytosis. On the contrary, cancer cells use this movement to metastasize from benign tumors to other parts of the body (Science Daily). Therefore, Sweden researchers questioned how this movement influences the process of cancer progression. These researchers found that most of the cells in our body are driven by the power of water.
Cells extend membrane projections to pull themselves around similar to that of an amoeba. These projections contain filopodia that detect chemicals in the surrounding environment. However, the actual movement is aided by the protein actin, or at least it was thought. Previously, scientists said that the protein created new fibers to make protrusions and then receded when the cell caught up with it, but Linköping researchers say that the movement is due to water?
Karlsson, a researcher at LiU, thinks that the protrusions aren’t due to the protein actin, but water. The team hypothesizes that water enters the cell then releases it back through channels when they need to move. These channels are known as aquaporins. To test this process the research team inserted the fluorescent protein GFP and aquaporins (AQP9) into living white blood cells. The results showed the white blood cells movement tremendously increased and the cells accumulated more protrusions. The cells absorbed water when they wanted to move which created pressure between the cell membrane and the cytoskeleton. This pressure made protrusions anchored by actin. This proved successful to the objectives of the whole project; “The aim of this study was to investigate the localization and dynamics of the water channel AQP9 in relation to actin dynamics in the development of filopodia and blebs.” (Plosone).
The researchers confirmed their thoughts when their results showed that the cells inserted with GFP-AQP9 developed more filopodia protrusions compared to that of their membrane labeled control vectors. These protrusions were created around areas of high water concentration therefore increasing osmotic pressure. In previous studies it has been shown that AQPs use the pressure to exert a forward push necessary for cell mobility and pressure relief.
Using this knowledge, researchers hope to stop the movement of malignant cancerous cells. There are thirteen different types of aquaporins and they hope that by closing some of these with inhibitors they could persuade the movement of cancer cells and aid research in cancer therapy (Science Daily). By slowing down and manipulating where tumors go scientists can remove tumors before they spread to other areas of the body. Furthermore, the researchers in Sweden hope that this new understanding for water migration aids in understanding other scientific research as the research on AQPs did for them. This research could be the beginning in new cancer technology and develop a further understanding for immune responses and embryo (stem cell) growth and movement.