Exam 3 - Cancer Flashcards
What is a neoplasm?
an abnormal growth of cells
What does it mean if a neoplasm is benign?
- not cancerous
- encapsulated by connective tissue
- non- invasive
What does it mean if a neoplasm is malignant?
- not encapsulated
- invasive of neighboring tissue
- metastasis
- results from a mutation of genes regulating the cell cycle
What does metastasis mean?
detach and lodge in distant places
- tumors easily fragment
- transported around body
carcinogenesis?
development of cancer
carcinogens?
things that could cause cancer
mutagens?
can cause mutations in genes
What are the characteristics of cancer cells?
- lack differentiation
- have abnormal nuclei
- form tumors
- undergo metastasis
- undergo angigenisis
what does it mean that cancer cells lack differentiation?
non-specialized ( don’t contribute to any function)
How do cancer cells form tumors?
- mitosis controlled by contact with neighboring cells
- contact inhibition = cells touch= they stop dividing
- cancer cells have lost contact inhibition
what does it mean that cancer cells undergo angiogenesis?
- formation of new blood vessels –> they funnel nutrients and hog it from normal cells
What is a carcinoma?
A cancer in the epithelial tissue
What is a sarcoma?
Connective tissue. bone and muscle
what is leukemia? lymphoma?
- blood-forming organs
- immune system
What are the origins of cancer?
mutations in DNA repair mechanisms
What are proto-oncogenes? What can they mutate into?
promote ( stimulatory) cell cycle in various ways
- mutate into oncogenes
What do tumor suppressor genes do?
-Inhibit the cell cycle
what is an oncogene?
cancer-causing genes permanently turn on the cell cycle
Mutations in which genes cause the growth of tumors?
- proto-oncogenes
- tumor suppressor genes
- both normally regulated in coordination with an organism growth plan
- if either mutates may lose control of the cell cycle = tumor formation
what is the most common mutation that leads to cancer?
P53 from G1 checkpoint
What is telomerase?
an enzyme that adds telomeres to the end of chromosomes
what are telomeres?
repeat sequences and specialized proteins at the tips of chromosomes
what is supposed to occur to telomeres as time goes on?
- get shorter with each cell division
- once very short they no longer divide
what happens when telomerase is mutated?
- keep adding telomeres
- cancer cells continually divide = immortal cancer cells
- 85-95% of cancers
