Intro Flashcards
What are the Top 2 cancers in the US?
1) lung | 2) colon cancer
What is lung cancer due to?
smokers/smoking
What is the #1 common cancer incidence?
skin cancer
What are the 2 common types of skin cancer?
melanoma and basal cell carcinoma
What is basal cell carcinoma from?
keratinocytes
What is melanoma from?
melanocytes
What is the main thing a cell must have the ability to do in order to potentially become a cancer cell?
ability to divide
Can a cell become a cancer cell if it has lost its ability to divide?
no
What are the 2 control mechanisms cells use to control cell growth?
growth factors | contact inhibition
What is contact inhibition?
density-dependent inhibition | when cell surfaces touch = signal that cells should stop growing at that point
Do tumor cells respond to cell growth control signals?
no, they lose anchorage-dependence
What is a primary tumor?
when the overgrowth of cells (not responding to contact inhibition) stimulates a tumor
What is a secondary tumor?
when primary tumors migrate to other parts of the body and begin proliferating there
Which tumor (primary or secondary) kills the patient/more dangerous and why?
secondary tumor = grows inside organs = organs deform and disrupt = organ stops functioning = organ failure
What is neoplasia?
new growth of tissue | aka: cancer
What is a tumor?
defined mass of tissue distinct from normal physiological growth | aka: cancer growth
What is oncology?
study of a mass or bulk
What are tumor suppressor genes?
control the cell cycle, cell death and cell survival
What do tumor suppressor genes act as?
breaks = so cells don’t replicate faster than they should
What will happen if a tumor suppressor gene has a mutation? Will this result in a tumor cell? Why or why not?
protein will not function normally = cell divides faster than normal | will need more than 1 mutation to result in a tumor cell
How are cancer cells independent of growth signaling?
due to oncogenes = ignore the stop signals
Which normal cells have a high metabolism such as tumor cells?
skin cells and blood cells = die often
Where do we get new cells from?
our adult stem cells
What are the 6 traits of cancer cells?
independent of growth signal | ignores STOP signal | doesn’t die (no apoptosis) | no limit to cell division | angiogenesis | metastasis
What is angiogenesis?
formation of blood vessels from the network of neighboring vessles | source of nutrients for cells
What is metastasis?
ability to move to other tissues
What are the 4 types of cell growth? Which one is the normal one?
metaplasia (normal one) | hyperplasia | dysplasia | neoplasia
What is metaplasia?
normal replacement growth of cells from adult stem cells
What is hyperplasia?
increase in cell number (may be benign) | not ok
What is dysplasia?
cells look different in size, shape, internal structure and organization | does not look normal
What is neoplasia?
full blown cancer | autonomous growth of tissue
What is hypertrophy?
increase in cell size
What are the characteristics of benign tumors?
encapsulated | non-invasive | slow growth | doesn’t spread (no metastasis) | highly differentiated
What are the characteristics of malignant tumors?
nonencapsulated = can enzymatically break down barriers | invasive | fast growth | metastatic | poorly differentiated
What does encapsulated mean when it comes to tumors?
surrounded/encapsulated by connective tissue barriers
What type of cell growth where we see internal abnormalities of cells?
dysplasia
What is de-differentiation?
terminally differentiated cell began to change genes and mutate = not look like what it was before
What is anaplasia?
cell regresses and no longer looks the way it’s supposed to
What are neoplastic cells?
malignant and spreads
If looking at the DNA sequence of a gene, what does the DNA sequence mean?
amino acid selection
How is the protein affected if its DNA sequence is mutated (changed)?
build the proteins wrong = won’t function = problems
Why is 1 mutation not enough to cause cancer?
due to back-up mechanisms
What does a 2nd mutation cause?
abnormal growth
What does a 3rd mutation cause?
gives cell an advantage = speed up tumor growth
What does a 4th mutation cause?
gives way for development of a more aggressive cancer but the tumor is still contained (benign)
What happens after the 5th mutation?
metastatic tumor but still too small to be detected
What is needed to form a secondary tumor?
tumor cell needs to attach to vessel wall = travel down vessel and enter tissue
What are the 10 characteristics of a cancer cell?
genetically unstable | heritable mutations | unresponsive to growth control signals | loss of function | no apoptosis | rapid growth | abnormal shape | high metabolic rate | escape from primary tissue | survive/proliferate in foreign sites
Are chemotherapeutic drugs cancer specific?
not specific to types of cancers, very generalized
Why do physicians prescribe sub-lethal concentration of chemotherapeutic drugs?
so it does not kill all cells, only highly metabolized ones since tumor cells are highly metabolic
How do tissues connect to blood vessels?
via diffusion happening through capillaries
Explain the competition for nutrients between highly metabolic cells and normal cells? What does this mean in terms of drug use?
highly metabolic cells take up more nutrients = they will take in more drugs than the normal cells too
How is cancer a disease of age?
the older you get = more you have accumulated DNA mutations
What are oncogenes?
normal genes made to make the cell divide
What are some of the advantages that mutations would give a tumor cell?
genes that inhibit proliferationthe invade other tissues via moving (walking genes) | survival genes | drug resistance genes
What are walking genes?
fibroblast genes
What genes do tumor cells have?
have the WHOLE genome
What are genes a tumor cell would delete?
anything inhibiting cell division - control genes
What are genes a tumor cell may want to duplicate?
replication (a cell cycle gene)
Why are tumor cells pseudo-immortalized rather than immortal?
referring to tumor population as a whole = tumor cells so unstable that a lot end up dying
What are most tumors: polyclonal or monoclonal?
monoclonal
What are polyclonal tumors?
origin is from multiple cell types
Why are polyclonal tumors harder to treat?
mutations are different
How can a tumor population be a heterogenous population?
cells can pick up mutations other cells don’t have
Why is it important to know that cells are able to pick up mutations to decipher mode of treatment?
some cells certain drugs target will die but other mutated cells may survive due to genetic differences
What is remission?
when cancer goes away
What is relapse?
cancer comes back
Why is stress involved with cancer development?
weakens the immune system
Why are most cancer treatments regimens and not just one drug?
heterogenous tumor population = patients with same cancer may have a different mix of mutations
How many genes do we have?
20,000
