T2 Lecture 10: Cancer Flashcards
Define neoplasm.
Abnormal mass of tissue produced when cells divide more than they should or do not die when they should.
AKA the tissue/cell is lacking its normal regulatory control.
Define neoplasia.
Process of formation of an abnormal growth.
Define proliferation.
The process by which cells divide and reproduce.
What are the two ways by which cells proliferate?
Meiosis and Mitosis
What mediates cell proliferation?
Gene expression, growth factors, and signaling molecules.
What is the specific kinase that regulates cell division?
mTOR, which also changes depending on local nutrition.
Define differentiation.
The process by which cells are transformed into different and more specialized cells.
What causes a cell to be differentiated?
Gene expression.
Influenced by growth factors and other stimuli
As a cell becomes MORE specialized, is it more or less likely to divide?
Less likely!
Important!!!!!!!!
What are stem cells?
Highly undifferentiated cells with SELF-RENEWAL
They have the potential to divide into multiple types of cells, which will eventually become fully differentiated cells.
What is a progenitor/parent cell? Why is it distinct from a stem cell?
It is still a cell that can divide, BUT parent cells have only a few options to differentiate into.
What are the 5 types of stem cells from most undifferentiated to most differentiated?
Totipotent: ALL CELL TYPES (AKA TOTAL RANGE)
Pluripotent: all adult cell types (PLENTY)
Multipotent: MULTIPLE cell types
Oligopotent: FEW cell types (Oligo means few/scanty)
Unipotent: ONE cell type
What are most progenitor cells in terms of stem cell ranking?
Oligopotent or unipotent.
Define carcinogenesis.
Origin and development of cancerous neoplasms
What kind of cells are most susceptible to neoplasia?
Rapidly dividing, labile cells
What percentage of cancers develop post birth?
95%
Define oncogenesis.
The mechanism by which normal cells BECOME cancer cells.
What is monoclonal origin?
The concept of cancer originating from a single cell with genetic mutations.
What 3 genes are responsible for making sure our cells do NOT develop into cancer?
Mutator genes
Protooncogenes
Tumor suppressor genes.
Define mutator genes.
They help repair mutated DNA and protect our genome.
The repair typically happens POST environmental insult.
Note: We have multiple mutator genes, so it is the failure of MULTIPLE that leads to us accumulating mutations and thus cancer.
Define protooncogenes.
Promote cell growth and development.
Specifically, they are normal genes that code for the proteins that regulate cell growth and differentiation, BUT they can become oncogenes.
Define tumor suppressor gene.
Control apoptosis, regulate cell division.
This is designed to ensure we have the optimal number of cells in our body. Therefore, failure of this gene = uncontrolled cell division = endless growth.
Does a single gene mutation usually cause cancer?
No!
What are the 3 tumor suppressor genes discussed in class? How are they distinct from each other?
TP53 (p53 protein) is found on chromosome 17.
It is often implicated in many colon, lung, and breast cancers.
Regulates apoptosis of CANCER cells post chemo/radiation.
RB Gene (Rb protein) is the first tumor suppressor gene ever discovered.
Associated with retinoblastoma and other cancers.
BCL2 gene (Bcl-2 protein) regulates apoptosis.
Mutation results in a POORER response to cancer therapy.
Often associated with leukemia and other cancers.