Cancer as a genetic disease Chapter 20

1. Cancer Outline What is cancer? What is the process leading to cancer? Common types of cancers. Germ line and Somatic mutations & cancer.

TUMORS Malignant Tumors are cancer! Benign

Cancer : Multi-step process Normal Many mutations Multiple mutations Gain of function Loss of function

Cancer : Multi-step process Initiation Clonal expansion Progression Expansion

Mutations Somatic Cell Germ Line

Scientists have also defined characteristics of a cancer cell.

2. Cancer Outline Characteristics of a cancer cell DNA and Cancer Cancer Prevention and Early Detection

Some Characteristics of a Cancer Cell Loss of contact inhibition Loss of apoptosis Tumor growth “in vivo”

Normal Fibroblasts Transformed Fibroblasts

Apoptosis: programmed cell death

APOPTOSIS: programmed cell death Example Bone cells

DNA and Cancer 1. Tumor suppressor genes 2. Proto- Oncogenes 3. Genetic Instability

1. Loss of Heterozygosity

Tumor Suppressor Gene Mutations Breast cancer (p53 gene) Retinoblastoma (rb gene)

2.

Cancer Karotype: Genomic Instability

Summary: some DNA links to cancer are Tumor Suppressors Proto- & Oncogenes Genomic Instability

Prevention and Early Detection

Cancer Prevention and Early Detection

Nobel Prize in 2002 for their discovery of apoptosis Brenner Horvitz Sulston

Hypothesis of origin of oncogenes Viruses recombine with proto-oncogenes Michael Bishop and Harold Varmus