Biochemistry 2280A Lecture Notes - P53, Telomerase, Growth Factor

• School: Western University
• Department: Biochemistry
• Course: Biochemistry 2280A
• Professor: Mel Usselman

Document Summary

Cancer cells divide in the absences of growth factors as they do not respond to signals that normally control cell division (for example, growth factors, hormones); that is, cancer cells do not need these signals to divide. Cancer cells are virtually immortal and do not respond to the normal signals that trigger cell death. Cancer is genetically unstable due to its defective in repair pathways (more point mutations), major chromosome abnormalities. A translocation between chromosomes 9 and 22 is responsible for chronic myelogenous leukemia. Metastatic cancer cells can escape to and proliferate in abnormal places. Avoid replicative cell aging that is programmed by the normal shortening of telomeres that occurs when cells divide. There are two major types of cancer-causing genes: oncogenes and tumour suppressor genes. An oncogene is a normal gene whose presence in an aberrant form causes cancer (dominant; gain of function). Examples of oncogenes include myc, ras, fos, jun, and abl.