What are cancer cells? Cancer cell is a kind of mutated cell, which is the source of cancer. Unlike normal cells, cancer cells have three major characteristics, namely, unlimited proliferation, transformable and easy to metastasize, and they are able to proliferate indefinitely and destroy normal cell tissues. Therefore, it is difficult to eliminate. How do cancer cells grow up by devouring? Cancer cells infiltrate into the surrounding normal tissues by destroying the normal cellular barriers while growing and enlarging the tumor. Normally, under a microscope, the demarcation line between normal tissue cells and their surrounding cells is clear. This clear demarcation is called the basement membrane. The skin, for example, has a basement membrane. It is also found in the lining of the ducts of the intestines, lungs, and breasts, and in the kidneys. One of the characteristics of cancer is that it crosses the basement membrane when seen microscopically. Currently, we know only a little about all the mechanisms by which cancer cells cross the basement membrane. For example, cancer cells can produce substances that disrupt cellular adhesions and, more specifically, the intercellular matrix. The intercellular matrix consists of many different substances, one of which is called collagen, which gives strength to the tissues in which it resides. Cancer cells produce a substance called collagenase (the term “so-and-so enzyme” usually refers to a hydrolytic enzyme that acts on the substance and breaks it down, e.g. lactase is the enzyme that hydrolyzes lactic acid). Collagenase also produces other substances, such as hyaluronidase, a group of substances called proteases, and other substances that help growing cancer cells to cross normal tissue barriers. How Cancer Cells Invade As a result, cancerous tissue has rough, irregular, and blurred edges. This is an important feature that distinguishes it from benign lesions. Benign tissues such as warts, benign tumors, and cysts have clear, distinct borders. Cancer cells affect surrounding structures as they infiltrate. Cancer cells themselves do not cause pain, but if the mass invades nearby nerves or extends into the periosteum or liver, it can stimulate the nociceptive nerve fibers in the area causing pain. Boundary of cancerous tissue