PATH 300 Lecture Notes - Lecture 4: Contact Inhibition, Keratinocyte, Antigen

• School: McGill University
• Department: Pathology
• Course: PATH 300
• Professor: Edith Zorychta

Document Summary

Start with one cell that is exposed to initiating agent ; accumulates mutations ; grows, spreads and can eventually end up killing us. Form a fertilised egg with xa and xb -> normally, mosaic of a or b develop. Tumor cells -> cloned abnormal cell surrounded by normal mosaic tissue. Stem cells : can subdivide in different lineages making the different types of cells in the blood. If become malignant : monoclonal tumor (leukemias, lymphomas : all cells are the same) If progresses further : sub divisions, slightly different groups of cells. Cancer cells are genetically unstable, keep accumulating mutations (sometimes 100 of them), many of them are not relevant to cancer but can be relevant to other features. Tumor can have a mixture of different cell types. Takes a while before detecting a tumor because we need a lot of mutations. E. g. lung cancer : 30 doublings to get to the smallest clinically detectable mass (1g of tissue)