3.4 Cancer 1 Flashcards
What is adenoma?
Benign epithelial tumor with glandular organization
What is adenocarcinoma?
Malignant tumor of same type
Cancers have names that reflect what?
Their tissue origin
Where is basal cell carcinoma?
Keratinocyte stem cell in skin
Where is melanoma?
pigment cells in skin
What is the major dif between basal cell carcinoma vs melanoma?
Basal carcinomas rarely metastasize whereas malignant melonomas metastasize widely
What is a property of cancer?
invasiveness
What does metastases mean?
cancer cells break loose and enter into blood or lymph, travel to new areas and form 2ndary tumors.
What kills cancer patients?
Metastases
How are tumors developed in colon cancer?
Mutation in APC gene. Form polyps. Mutation in Ras becomes a cancer gene. Tumor moves out into bloodstream
True or False? Most cancer derive from a single abnormal cell
True
What is some evidence that most cancers derive from a single abnormal cell?
Philadelphia chromosome
Cancer cells contain what type of mutations?
Somatic
Carcinogenesis is linked to what?
Mutagenesis
What are two types of carcinogens?
Chemical and radiation
What is the best weapon against cancer?
Early detection
What things do cancerous growth depend on?
Defective apoptosis or defective growth
What is the most deadly aspect of cancer?
Metastasis
What are some properties of cancer?
Self sufficient, less prone to apoptosis, induces angiogenesis. invasive to other tissues.
What are the two genetic causes of cancer?
tumor suppressor genes and oncogenes
What are cancer critical genes?
genes whose alteration frequently results in cancer.
What are the two broad types of mutations in cancer?
Overactivity and underactivity.
What type of mutation are oncogenes and tumor suppressor genes associated with?
Overactivity-oncogenes. Underactivity-tumor suppressor.
How do overactivity mutations happen?
single mutation event and activation of gene causing proliferation
How do underactivity mutations happen?
One gene no effect, 2nd mutation causes problems.
What can also cause cancer?
Viruses
What is RSV and what can it do?
A retrovirus that can cause cancer in chickens.
How do retroviruses causes cancer?
They hijack proto-oncogenes and activate them by either over-expression or cause them to be an oncogene.
what was the first human oncogene?
Ras
What is Ras?
Monomeric GTPase for signal transduction
Ras oncogenes cant shut off by hydrolyzing GTP to
GDP
Oncogenes are associated with
gain of function
What are 4 ways to activate oncogenes?
Deletion or point mutation. Regulatory mutation. Gene amplification. Chromosomal rearrangement.
What are 5 other ways to activate oncogenes?
Ligands, receptors, TF, cell cycle proteins, proteins that inhibit apoptosis.
How do ligands produce cancer?
If ligands produce constructively they cause proliferation
How do receptors cause cancer?
when RTKs are constructively produced.
How do TF cause cancer?
Can constantly induce transcription.
How do cell cycle proteins cause cancer?
Anything that can cause cell proliferation
What is an example of a rearrangement mutation?
BCL2 oncogene
How does B cell lymphoma originate from?
From translocated gene. 18 onto part of 14.
What is the dif between oncogenes and tumor suppressor genes.*
Oncogenes are gain of function, tumor supressor are loss of function. Oncogenes need one mutation, tumor supressor need two mutations.
Name two ways in which proto oncogenes are activated into oncogenes**
Viruses. Overactivity.
Name 3 properties of cancer cells*
Self sufficient, less prone to apoptosis, induces angiogenesis. invasive to other tissues.
