Lecture 4 Flashcards
what are more common sarcomas or carcinomas
carcinoma
which layer of skin does the sarcoma originate
mesoderm
describe sarcomas from hematopoietic tissues
Blood-forming
arise from non-epithelial cell
embryonic mesoderm
what are similarities and differences between carcinomas and sarcomas
Both malignant tumours
carcinomas arise from epithelial, sarcoma from the musculoskeletal system
carcinomas are more common
carcinomas usually affect older people while sarcomas can afflict young people also
carcinomas spread different from sarcomas
what are some things that triggers cancer
Retrovirus
physical agents (x-rays)
chemical agents (carcinogens)
what did katsusaburo yamagiwa discover
had one of the earliest scientific evidence showing that chemical agents can induce cancer.
rubbed quarters on rabbit ears to induce cancer
Whats the Ames test
applying various carcinogens to a culture of salmonella bacteria and score the abilities of these carcinogens to mutate bacteria
how do you test if a carcinogen can function as a mutagen
Ames test
what are the controls for the ames test
His- test, His- extract, His- test + extract, His-, His+ WT
what are some limitations of the ames test
A bacterial cell won’t respond the same as a human
A mutagen isn’t necessarily a carcinogen
Many carcinogens fail the test
Uses rat liver
more tests needed to know if its a carcinogen
What are oncogenes
a proto-oncogene that has been activated by mutation or overexpression, gain of function
What did Peyton Rous discover
implanted small fragments of sarcoma of chicken to other birds, tumours at the site of injection
discovered a virus that causes cancer in chickens
the sarcoma-inducing agent was later called Rous Sarcoma Virus
What is the Rous Sarcoma virus
A virus that can transform a normal cell into a tumour
What does BRK do
enhances breast tumour growth
What does FRK do
Suppresses glioma trumor progression
what strategy was initially used to detect nonviral oncogenes
transfection of DNA of transformed cells (mouse to mouse)
What are proto-oncogenes
Normal cellular genes involved in cell growth/division
how does a proto-oncogene become an oncogene
Mutation
amplification (overexpression)
gene translocation
what’s adenocarcinoma
malignant cancer in epithelial cells that secrete substances in ducts or cavities to protect the epithelial cell layers from the contents of the cavities
what’s squamous cell carcinoma
malignant cancer in epithelial cells which form protective cell layers
what are the 3 types of non-epithelial tumors
Sarcomas: connective tissues
Hematopoietic malignancies: blood-forming tissues
Neuroectodermal tumors: Central and peripheral nervous systems
what are melanomas
Melanocyte tumors
what are small-cell lung carcinomas?
Neurosecretory cell tumor
What are teratomas
Embryonic cell tumor
How do you describe cancer of unknown primary (CUP)
anaplastic tumor
what type of cancer is leukemia/lymphoma
cancer in blood-forming cells, hematopoietic malignancy
How do carcinogens induce cancer
Mutating critical growth-promoting (proto-oncogenes) or tumor suppressor genes
What was Rous’s protocol for inducing sarcomas in chicken
remove sarcoma from chicken, break tissue into fragments, grind up sarcoma with sand, filter and collect filtrate, inject into young chicken, observe sarcoma
T/F normal cells require tethering to a solid substrate before it can grow
true, normal cells are anchorage-dependent
T/F transformed cells are anchorage-independent
True
