Scientists at the Massachusetts Institute of Technology have found that cancerous tumors are surrounded by an elastic film that becomes tougher as defective tissue grows. This limits the ability of malignant cells to form metastases, which are observed in especially dangerous forms and stages of the disease, and helps to curb tumor growth. The discovery is reported in an article published in the journal Proceedings of the National Academy of Sciences.
The basement membrane is a thin non-cellular layer that surrounds not only cancerous tumors, but also healthy tissues. It serves as the physical support that holds the organs, gives them shape, and also provides a pathway for cell migration. In cancer, malignant cells must disrupt the integrity of the membrane in order to migrate to another part of the human body and begin to form metastases.
To study the properties of the basement membrane surrounding the tumor, the scientists used atomic force microscopy, in which a microscopic probe was applied to a thin membrane. The sample was a cultured culture of breast cancer cells that secrete proteins that form a membrane around tumor spheroids. Liquid was pumped into the spheroids through tiny needles, causing the membrane to inflate, separating from the cells. This made it possible to measure the elasticity of the shell.
It turned out that the membrane remains elastic as it inflates, but increases its rigidity, which provides some control over tumor growth. This distinguishes the casing from other types of elastic materials, which can burst when inflated. In this case, cancerous tumors could become much more dangerous for the body.
In future research, scientists plan to find new ways to prevent or delay cancer metastasis by further increasing the rigidity of the basement membrane.