Stages of Neoplastic Transformation

Activation A healthy cell is exposed to a carcinogen

BAD Carcinogen: contributes to causing cancer; creates free radicals Free radicals = charged compounds If a compound located in a cell has a charge on it, it behaves differently Cellular chaos ensues If charges build up in the nucleus, it may cause a problem with mitosis

BAD It would be better if the charge created enough of a problem that it killed the cell Instead, it causes chemical chaos inside of the nucleus (in genes that control mitosis) Creates mutated cells

Free Radicals

GOOD Anti-oxidants (released by peroxisomes—organelles) Body’s defense: Anti-oxidants (released by peroxisomes—organelles) Over the counter anti-oxidants: Vitamin E (shows no anti-cancer characteristics) Beta carotene (form of vitamin A) Flavonoids (found in red fruits)

http://www.youtube.com/watch?v=bmAMtPEv-0M

Initiation Abnormal division that produces abnormal cells

BAD Carcinogen: Oncogene: abnormal gene that controls mitosis

GOOD Tumor suppressor gene Stops the oncogene through either promoting apoptosis or repressing the cell cycle and allowing DNA to repair

P53 gene: one of many tumor suppressor genes In over 50% of lung cancer cases, patients have a defective p53 gene

Promotion Continuation of Initiation Leads to a neoplasm Neoplasm: Abnormal mass of cells/tissue

BAD Adult body produces approximately 6 or 7 neoplasms a day that your body fights off

GOOD Immune response Killer T-lymphocytes We make lots (4 billion) of wbc every day (mostly at night) They “recognize” the different markers on the cancer cells

Killer T Cells Attacking a Cancer Cell ©http://www. cancer-info

Problem? Suppressed immune system

Cancer is usually not that fast growing It mitosis at the rate of the normal tissue in which it is found As neoplasm forms, angiogenesis occurs

Angiogenesis: growth of new blood vessels In tumors, it is called TAF Tumor angiogenesis factor