Cancer Flashcards
4 Major types of cancer.
Carcinomas (Epithelial cells)
Sarcomas (Bone and muscle)
Hematopoietic (Blood)
Neuroectodermal (nervous system and skin)
Define Monoclonal
Tumor that originates from 1 cell
Modifications that convert Proto-oncogenes to Oncogenes
Missense mutation
Gene Amplification
Chromosomal translation
Retroviral insertion
How does missense mutation create oncogenes
Genetic sequences change that cause transduction creating different phenotypes to be expressed.
How does Gene amplification create oncogenes
A gene is copied too much creating abnormalities.
How does Chromosomal translocation cause cancer
Chromosome breaks and is improperly fused with another. Leading to cancer.
How does Retroviral insertion create oncogenes
Viruses add Cancer RNA to genome which then get copied.
Define Dysplasia
Cells forming abnormal epithelium and and underdeveloped polyps
How do cells achieve immortalization?
When a cell adapts perfectly and can proliferate w/o limit
Telomeres become lengthened
Characteristics of cancer cells.
Unlimited division
Anchorage independence
Chromosomal damage
Reduced growth factors
Define Metastasis
Tumor cells that wander throughout the body and begin to proliferate in different organs
What is loss of heterozygosity?
Loss of a genotype because of copying errors on the chromosome
How does loss of heterozygosity influence cancer
Tumor suppressor genes (TSGs) are often deleted from chromosome.
How can a mutation on a single gene target multiple phenotypic characteristics at the same time?
Alteration in chromosomes create a coding for different phenotypes
What is the most likely explanation for a specific cancer to appear in several members of the same family?
Genome of cells has observed a mutation that gets passed along via the gametes through miosis
What is a “magic bullet” to cancer?
A magic bullet is a drug that targets a tumor and carries a toxin.
What is p53?
p53 is a protein that suppresses tumors by arresting the cell cycle.
How is apoptosis modified in cancer
Proteins need to be turned off so proteins can initiate apoptosis.
How can cancer cell access vital supply
By growing new blood vessles
What is angiogenesis
Growth of new blood vessels
Define malignancy
Aberrant (unusual) growth
How does mutation on Rb protein lead to cancer?
Mutations inactivate and remove Rb proteins so they cant function at R check point.
How can virus modify the cell cycle and induce cancer?
Addition of RNA that effects the cell cycle.
What are two molecular mechanisms that inactivate tumor suppressors
Silencing through methylation of Cytidines (RNA)
Mutations of TSG alleles
Define Hyperplasia
Increased # of cells.
Explain the pleitropical effect of a mutated gene in cancer.
Different phenotypes are observed on different tissue
Why is p53 considered a tumor suppressor protein?
Because it can put the cell into arrest.
How can a proto-oncogene be activated to become an oncogene?
Growth signal is stuck on.
Growth signal activated when ligand isn’t present
(autocrin siglaning)
Why is cancer considered progressive?
Begning to malignant to metastasis
