BMS 110 Cancer and Mutations

Mutations

affect one gene, small deletions, duplications, mutations

chromosomal mutation

affects multiple genes, larger region of chromosome is changed

genome mutations

affects chromosome number, caused by nondisjunction, results in monosomy and trisomy gametes

trisomy

2n+1

monosomy

2n-1

nondisjunction

the failure of chromosomes to disjoin (separate) normally during meiosis

mutated gene results in…

no protein produced, or abnormal protein (random function)

Apoptosis

cell programmed death, self destruct

point mutations

1. frameshift 2. silent mutation 3. missense mutation 4. nonsense mutation

DNA repair cycle

1. DNA damage is detected 2. cell cycle is paused 3. DNA is repaired 4. Cell cycle is restarted

What happens when cell is fixed incorrectly (or not at all)

Disfunction, disease, or self destruct

silent mutation

codon is changed but codon still codes the same nucleotide

GAA = Glu

GAG = Glu

Missense mutation

codon is changed so it encodes a different amino acid, effects function of the protein

GAA = Glu

GAC = Asp

Nonsense mutation

codon is changed for a STOP codon

GAA = Glu

UAA = Stop

who repairs DNA

DNA polymerases and other enzymes repair replication mistakes

what are the cell cycle check points (Quality Checks?)

G1, G2, S, M

how often are DNA polyeramase errors

1/100,000,000 base pairs

Cancer names

carcinogenesis, oncogenesis, tumorigenesis

what are the mutations needed for cancerous cells?

Tumor-suppressor gene AND Proto-oncogene

Tumor-suppressor gene

stops cell growth, prevents cancer from developing, stops oncogenes

Proto-oncogene gene

promotes cell growth and cell division, the "accelerator", when mutated becomes oncogene

oncogene

a mutated proton-oncogene that causes cancer, cells no longer listen to the control signals.

does NOT cause malignant cancer by itself.

P53 gene

tumor suppressor and proto-pnco gene that regulates cell cycle, prevents entry into S phase if DNA damage is detected, arrests cell cycle until fixed or dies.

abl enzyme

enzyme that turns things on, including cell division

bcr protein

protein on all the time

abl and bcr TOGETHER

on all the time, causes cancer cells

BRCA1 and BRCA2

DNa repair genes, tumor suppressor genes, important for proper repair of double stranded DNA breaks

These genes CAN be passed down

what do mutations allow

allows cells to accumulate more mutations

hereditary role in cancer

plays a major roll in 5% of all cancers

carcinogens role in cancer

substances that are capable of causing cancer by damaging cellular DNA and disrupting regulatory processes of the cell

ex. UV radiation

cancer cells have…

a larger nuclei, different shapes and sizes, abnormal amount of chromosomes

Dysplasia

look cancerous, are not yet cancerous, a warning

benign

abnormal cell growth that doesn't spread

ex. moles, freckles, skin tags

Hyperplasia

increases cell division and branching out due to influx of resources to grow

Angiogenesis

formation of blood vessels from pre-existing blood vessels, gets more resources to the cancerous cells

metastasis

cancer moves through blood.lymphatic vessels throughout the body and then colonizes new location

carcinogen types

1. physical (UV radiation) 2. biological (viruses) 3. chemical (heavy metals)