contrast to normal cells cancer cells often exhibit much more variability in

Contrast to normal cells cancer cells often exhibit

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contrast to normal cells, cancer cells often exhibit much more variability in cell size some are larger than normal and some are smaller than normal. In addition, cancer cells often have an abnormal shape, both
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of the cell, and of the nucleus (the “brain” of the cell.) The nucleus appears both larger and darker than normal cells. The reason for the darkness is that the nucleus of cancer cells contains excess DNA. Up close, cancer cells often have an abnormal number of chromosomes that are arranged in a disorganized fashion. The rate of growth: Normal cells reproduce themselves and then stop when enough cells are present. Cancer cells reproduce rapidly before the cells have had a chance to mature. Maturation: Normal cells mature. Cancer cells, because they grow rapidly and divide before cells are fully mature, remain immature. Doctors use the term undifferentiated to describe immature cells (in contrast to differentiate to describe more mature cells.) Another way to explain this is to view cancer cells as cells that don’t “grow up” and specialize into adult cells. The degree of maturation of cells corresponds to the "grade" of cancer. Cancers are graded on a scale from 1 to 3 with 3 being the most aggressive. Evading the immune system: when normal cells become damaged, the immune system (via cells called lymphocytes) identifies and removes them. Cancer cells are able to evade (trick) the immune system long enough to grow into a tumor by either by escaping detection or by secreting chemicals that inactivate immune cells that come to the scene. Some of the newer immunotherapy medications address this aspect of cancer cells. Functioning: Normal cells perform the function they are meant to perform, whereas cancer cells may not be functional. For example, normal white blood cells help fight off infections. In leukemia , the number of white blood cells may be very high, but since the cancerous white blood cells are not functioning as they should, people can be more at risk for infection even with an elevated white blood cell count. The same can be true of substances produced. For example, normal thyroid cells produce thyroid hormone. Cancerous thyroid cells ( thyroid cancer ) may not produce thyroid hormone. In this case, the body may lack enough thyroid hormone ( hypothyroidism ) despite an increased amount of thyroid tissue.
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Blood supply: Angiogenesis is the process by which cells attract blood vessels to grow and feed the tissue. Normal cells undergo a process called angiogenesis only as part of normal growth and development and when new tissue is needed to repair damaged tissue. Cancer cells undergo angiogenesis even when growth is not necessary. One type of cancer treatment involves the use of angiogenesis inhibitors medications that block angiogenesis in the body in an effort to keep tumors from growing.
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  • Fall '17
  • DR. MOSLEY

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