One of the characteristic properties of tumor cells is their ability to penetrate normal tissues and penetration into the channels of blood and lymph channels. In this case the tumor cells often use structures that already exist that facilitate infiltration, such as perineural cavity.
On the other hand, the expansion can be dipersukar by such structures until an organ or periosteum. It is possible that many factors affect imfiltrasi. There is a TV CONNECT that increase pressure in the tumor as a result of the addition of tumor volume, tumor cells penetrate easier into normal tissue.
Although the experiments by Young models support this conjecture but it is unlikely that this is the most important reason for the invasion. Tumors that grow slow sometimes showed extensive infiltration surrounding the tumor was growing rapidly sometimes only slightly infiltrate the surrounding tissue.
However, observations show that the palpation of the tumor is often followed by the spread of tumor cells in the blood stream. One with another adhesion and motility of tumor cells with different malignant cells are not malignant. Both malignant cells and non-malignant can move in vitro.
But if the benign cells in vitro in contact with one another, the motility and often also growing very subtract ('' contact inhibition '') (Abercrombie). Malignant cells do not show '' contact inhibition 'is, or if there is only little once.
The cells continue to grow without restrictions and rules and form nests ('' piling up '). Tumor cell motility is often also not inhibited by contact with fibroblast-fibroblast. The phenomenon of the nullification '' contact inhibition '' This may also be the basis of invasive growth in vivo.
For this phenomenon has not obtained a satisfactory explanation. Anticipated levels and kinds mukopolisakharida in a thin layer which is '' glycocalyx '' outside the plasma membrane, plays a role in these interactions.
Adhesion to one another from the malignant tumor cells are smaller than those found in benign cells of the same type. Coman showed that cells of normal stratified squamous epithelium is more difficult to separate than epidermoid carcinoma cells.
He argues that this lack of adhesion is due to lack of calcium levels in malignant cells. Later investigations, including by Patinkin and his colleagues, doubted the role of calcium in these circumstances. Although there is no clear explanation of the lack of adhesion to one another of malignant tumor cells of these factors appears to be important also for infiltrative growth.
Various investigators provide an important role in the production and expenditure-enzyme lytic enzymes by tumor cells. Enzyme-enzyme is considered to decide the adhesion of tumor cells to each other and also the relationship between the cells around the tumor. Intercellular substance in normal tissue is broken down.
Although the results of the various experiments did not show similarity, at this time appears to be primarily a lysosomal enzyme-enzyme plays a role in the occurrence of invasive growth. Enzyme-enzyme is probably a product of the tumor cells were alive but may also enzyme-enzyme produced by macrophages.
How far is the reaction of the organism to the presence of the tumor can affect the growth of this invasive, yet clear. Vasiliev showed a proliferation of connective tissue around the tumor that helps the spread of tumor cells. Tumor cell migration, according to this view, takes place following the connective tissue formed.
Smeulers strengthen this hypothesis in experiments with transplanted tumor tissue in '' chorion allantois' chicken eggs. Invasive growth mechanisms are still largely be explained. What is certain is that we are dealing with a process that is influenced by various factors.
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