Checkpoint proteins such as p53 are not necessary for
normal cell growth and division.
E cadherin
________- keeps cells of tissue adhering to each other.
DNA alterations can lead to effects on
gene expression that ultimately affect cell division, and thereby lead to cancer.
Integrins
________- keeps cells adhering to their substrate.
Replicative senescence
________: finite number of cell divisions most likely due to loss of telomerase activity.
Sarcomas
________: arise from connective tissue or muscle cell.
Missense mutations
________: chemical mutagens have been shown to cause ________ leading to cancer.
Cancer
________: the continuous uncontrolled growth of cells.
cell division
An oncogene may promote cancer by keeping the ________ signaling pathway in a permanent "on "position.
Carcinomas
________: cancers arising from epithelial cells.
viral genome
Some viruses cause cancer because they carry an oncogene in the ________.
Leukemias
________: hematopoietic cells and nervous system.
Malignant
________: cells have acquired ability to invade surrounding tissue.
Tumors can arise from
any cell type in the body.
Growth factors bind to
cell surface and initiate cascade, activating specific genes, leading to cell division.
If a proto-oncogene becomes overexpressed,
it will promote cancer.
Retroviral insertions
________: viral DNA inserts into a chromosome, putting a viral promoter next to a proto- oncogene.
Gene amplifications
________: increase in copy number results in too much protein.
somatic cells
Most carcinogens, such as UV light and certain chemicals in cigarette smoke, are mutagens that promote genetic changes in ________.
Proteins called cyclins and cyclin- dependent protein kinases (cdks) are responsible for
advancing a cell through the four phases of the cell cycle.
Checkpoint proteins
________ check the integrity of the genome and prevent a cell from progressing past a certain point in the cell cycle.
If the damage is minor, p53
halts the cell cycle until the damage is repaired.
Tumor
any abnormal proliferation of cells
Benign tumors
stay confined to its original location
Malignant tumors
capable of invading surrounding tissue or invading the entire body
Neoplasm
tumor
Benign
cells of neoplasm are clustered together
Leukemias
hematopoietic cells and nervous system
Replicative senescence
finite number of cell divisions most likely due to loss of telomerase activity
Carcinogens
agents that increase the likelihood of developing cancer
Mutations in genes for cell growth signaling proteins can change them into oncogenes
producing abnormally high level of activity
Chromosomal translocations
two chromosomes break and switch ends
Oncogene
mutant form of a normal gene
E-cadherin
keeps cells of tissue adhering to each other
p53
about 50% of all human cancers are associated with defects in this gene
ex
Rb (retinoblastoma)