CANCER A. Characteristics of Cancer Cells 1. Structural Abnormalities a. Has an abnormal large nucleus and less cytoplasm then usual b. Poorly differentiated.
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CANCER A. Characteristics of Cancer Cells 1. Structural Abnormalities a. Has an abnormal large nucleus and less cytoplasm then usual b. Poorly differentiated c. When the transformed cell divides, its daughter cells are cancerous cells too.
2. Uncontrolled Growth a. Normal cells - contact inhibition Cancerous cells – no contact inhibition. As a result, cancer cells pile up in a disorganized lump. b. Lack cell-to-cell adhesion with neighboring cells. They may form extensions (pseudopodia) that enable them to move about (metastasis) – malignant.
c. Some cancer cells produce interleukin –2, which stimulates cell division and also display receptor for it d. Cancer cells secret a growth factor, angiogenin, encourage new blood vessels to grow around the tumor.
B. Carcinogenesis : the onset of cancer Proto-oncogenes – are normal genes that regulate cell growth and development. They may change their structure or expression, they may become oncogenes. Oncogenes – a DNA segment that can cause caner. a mutated gene that can help make a cell cancerous; genes normally turns ON cell growth or division
MUTATIONS DNA ( deoxyribonucleic acid) change and can transmitted from one generation to another. Caused by mutagens. Results from : * normal metabolism (free radicals), * chemicals (mutagens/pollutants), * radiation (sunlight, chemicals), * genetic translocations, disorders.
Onset of malignant cancer requires mutations in several genes: Tumor suppressor gene – prevent cancer from occurring e.g. p53 a very important tumor suppressor gene can prevent change. Mutated p53 genes found in cancers of breast, bone, colon, skin, lung, bladder, cervix, and brain. Oncogen Activation When there is mutation, triggers expression of oncogen.
Other Routes to Carcinogenesis 1. Inherited Susceptibility to Cancer 2. Viruses DNA tumor viruses RNA tumor viruses 3. Chemical Carcinogens By-products of the industrialization of human societies e.g. asbestos, coal tar, benzene, hydrocarbons in cigarette smoke, and some pesticides. 4. Radiation X-ray, UV and some radioactive materials cause mutation
C. Some Major Types of Cancer Cancer is categorized according to the tissue in which it arises 1. Sarcomas – connective tissues 2. Carcinomas – epithelium 3. Adenocarcinomas – glands or its ducts 4. Lymphomas – lymphoid tissue 5. Leukemia – blood forming regions such as bone marrow
Things we can do that may lower our risk of developing cancer Drink green tea Cook with olive oil Eat garlic Eat fruit and vegetables, which are rich in anti-oxidants Exercise/stimulate immune system Use sun tan lotion, avoid getting burned