abnormal accumulation of cells by altering:

• proliferation rate
• rate of apoptosis
• differentiation capacity
• invasive capacity

Cancerous cell observed by:

• migration (movt through tissue)
• metastasis
• angiogenesis (new blood supply)

• normally equilibrium b/t gene expression of positive and negative regulation
• inc expression
• temporal deregulation
• production of abnormal gene product

• positive stim for cell proliferation and abnomal expression/activation create oncogenes
• inactivate tumor suppressor genes
• dominant phenotype
• Kras

• abnormal expression of gene which acts which acts to inhibit cell proliferation
• loss of gene product
• mutation of gene product
• inhibition of gene product function
• recessive phenotype
• APC, p53, SMAD4

• cancer occurs in families more often than by chance envt or hereditary factors

• cancer occurs due to inheritance of altered gene within family

• Retinoblastoma --> Retinoblastoma
• p53 --> Li-Fraumeni Syndrome
• APC --> Familial Adenomatous and Polyposis Coli

Rb inhibits transcription of genes with E2F binding sites

• inhibits c-Myc
• Tumors in one or both eyes
• affects toddlers and infants
• require 2 or 1 gene change
• leads to inactivation of both Rb alleles

• Li-Fraumeni Syndrome --> neoplasms throughout body
• dom neg interaction to inactivate p53
• mutations in p53 in >50% human tumors
• gene activated by variety of stimuli (leads to cell growth arrest and/or apoptosis of damaged cell)