Repeated sequences not used to make cell proteins
Telomeres -as cells divide, more and more telomeres are lost -there is an association between telomere loss and cell death
How do cancer cells affect telomeres
They replace telomeres by activating telomerase, thus can divide indefinitely or are “immortalized”
Changes in both oncogenes and tumor suppressor genes are typically required for FAP to develop. T/F
True
Cells that can no longer divide are ______
terminally differentiated
An example of how multiple genetic changes are often required for cancer to arrise
Familial Adenomatous Polyposis (FAP)
Cancer is genetic, but not necessarily inherited. T/F
True. Cancer always involves mutations, we don’t always get those mutations from our parents, usually from being exposed to an environment.
Examples of chromosomal changes
- aneuploid- loss of diploid state
- translocations and other rearrangements
- chromosomal instability
Characteristics of benign neoplasms ‘tumors’
Well differentiated and are localized
3 phases of tumor growth
- Initiation
- DNA mutation, irreversible
- must occur first
- Promotion
- Stimulates cell proliferation
- reversible in early stages
- must follow initation for tumors to form
- Progression
- malignant phenotype
- invasiveness, metastasis
- autonomous growth
- genomic instability
A well localized tumor with no evidence of metastasis would most likely be treated with?
Surgery
Which of the following indications are related to blood loss in our patient? -Dark stools -Low hemoglobin levels -Fatigue -All of the above
All of the above are related to blood loss.
mutations in ____ are assosociated with many types of cancer
p53
if DNA is not repaired, new mutations will be passed on to cell progeny, and if these mutations alter growth signals, cancer may result
mutations in p53 are associated with many types of cancer
Diagnosising and staging of tumor growth
- TNM
- Tumor
- Nodes
- Metastasis
A type of cancer due to mutations in DNA repair genes
HNPCC- Hereditary nonpolyposis colon cancer
- This decrease in DNA repair leads to an increase in genome instability
- Damaged DNA repair gene cannot correct the errors within newly replicated DNA
- ‘mutator phenotype’ increases the likelihood that an individual will develop cancer
A cell protein that has a number of anti-cancer functions centered around DNA repair
p53
- activation of DNA repair proteins
- arrest of the cell cycle to allow DNA repair proteins time to fix mutations
- initiation of apoptosis if DNA damage cannot be reversed
The ability of a cell to divide and requires growth signals including growth factors that stimulate the cell to divide by mitotic division
Proliferation
Normally restrain cell growth, if mutated may form proteins that do not work (loss of function)
Tumor Suppressor Genes examples: -transcription factors (pRB and p53) -Cell adhesion proteins (APC and DCC)
mutate BOTH copies
Mutations in both alleles of _____, which normally prevent tumors, are required in order to see changes related to cancer.
Tumor suppressor genes
when lose both alleles due to mutation you lose the function of that gene to suppress the tumor growth
The more undifferentiated, the greater the capacity to proliferate, and the more _____ the cancer
malignant
Elevated levels of ____ are associated with certain cancers and can be used clinically to assess responses to treatment
carcinoembryonic antigen (CEA)
Cells become more _____ as they mature
specialized
Acts as a brake to the cell as this protein governs cell cycle commitment
pRB
- -its activity is governed by phosphorylation (adding or removing a phosphate group)
- disruption of pRB leads to increased cell proliferation
- commonly found in cancer cells
The cell cycle in cancer cells is affected by 3 underlying causes of growth and maturity abnormalities…
- The ability to produce the enzyme telomerase
- Changes in the pRB gene, which governs the cell cycle rate
- Changes in the p53 gene, which slows the cell cycle to allow for repair of DNA mutations before cell division
Most people diagnosed with colorectal cancer have a primary relative who also has colorectal cancer. T/F
False. Many of these mutations are acquired from their environment.
