Researches On The Mechanical Characteristics Of The Gastric Cancer Cells In Mice

Cell Traction Force (CTF) is the force exerted on the extracellular substrate by thecell, and it is an important physical parameter. CTF involves many complex signaltransduction pathways. It plays an important regulation role on cell proliferation,differentiation, signal transduction, migration and apoptosis. It is closely related to thedevelopment of many serious diseases. Tumor cells exhibit many differences in terms ofcharacteristics compared with normal cells. The reports about this aspect are also unusual.This experiment studied mice gastric cancer cells dynamic changes for induceddifferentiation. The purpose was to explore the changes mechanism of cell traction force inthe process of carcinogenesis.The methods and conclusions were as follows：1. The normal gastric cells and gastric cancer cells culture.. Getting the normal gastrictissue from mice by using the digestion method. And placing them in the CO2incubator.Observing the growth state of cells by using the inverted microscope after3~4days.Replacing the culture medium and removing non-adherent cells at the same times.Expanding cultivation when the cells formed better colonies. Multiplying the nextgeneration every three days. Selecting cells which grew well to make climbing films andthe rest of them were cultured.The gastric cancer cells made models in the body, using the digestion method to getgastric cells and placing them in the CO2incubator. Multiplying the next generationaccording to the growth conditions every three days. Making climbing films and the rest ofthe cells were cultured.2．Specific staining on microfilaments with phalloidin. Using the characteristics ofphalloidin specific staining on microfilaments to make marks in cytoskeletons. Thenobserving the changes of microfilament distribution features for gastric cancer cells. Theresults showed that the microfilaments were sparser before the induced differentiation.They arranged irregularly and formed reticular structure. This structure contained energy.After the induced differentiation, the microfilaments were relatively denser. Distorted state disappeared and arranged regularly. The energy was released. This indicated that cellscanceration made the cytoskeleton produce great changes.3. The α-SMA protein detection. Using fluorescent antibody staining and Westernblotting technique to detect α-SMA protein contents of gastric cancer cells in mice beforeand after induced differentiation. And normal gastric cells were needed as a reference. Itwas found that the gastric cancer cells showed a low α-SMA protein content beforeinduced differentiation. They were relatively loose. The expression of α-SMA protein washigher and relatively dense after induced differentiation. The contents were closer toα-SMA protein contents which were in normal gastric cells.4. The measurement of cell traction force. Using CTFM (Cell Traction ForceMicroscopy) to measure cell traction force. The results showed that the traction of gastriccancer cells in mice before and after induced differentiation changed very significantly.The root mean square value increased from279pa to565pa, which was increased abouttwice. The average of cells,projected area also increased from690um2to963um2, whichwas increased about39.6%. The Maximum traction force of mice gastric cancer cellsincreased from1400pa to1800pa. The changes of cell displacement left on the substratewere also very significant. They increased from2.2um to2.5um.