Basic Genetics of Neoplasia Flashcards
Where is genetic information stored?
In DNA (deoxyribonucleic acid)
What is the function of genes?
They code for a protein
What is the function of a protein?
It has a task (from the gene) and does the task
What do DNA repair genes do?
Continuously read through genetic code to check for error
Why would a codon thats supposed to read ACC but is read ATC a problem?
The cellular function will be compromised by this mistake and must be fixed.
In this situation: A codon thats supposed to read ACC but is read ATC.
How would DNA repair genes fix this?
Through a single nucleotide base change due to an insertion, deletion, or subsitution
What targets DNA repair genes so that you can’t check for errors?
Carcinogens
What are the categories relating to tumors?
- Proto-oncogenes
- Tumor suppressor genes
Proto-oncogenes?
Enhance cell division (good to have because they oppose homeostasis).
They are normal genes that become cancer-causing genes if mutated.
What are proto-oncogenes associated with?
Gene overactivity
What occurs if proto-oncogenes become mutated?
You end up with uncontrolled cell growth (defective protein -> defective growth) -> Tumor
What are tumour suppressor genes?
Inhibit cell division
If mutated what does the tumor suppressor genes cause?
They cause uncontrolled growth and tumor formation
What are tumor suppressor genes associated with?
gene underactivity
What is TP53?
A gene that causes apoptosis of cell if DNA damaged.
What does TP53 code for?
P53 (protein)
What is the main target for DNA repair genes?
Cancer
Oncogenes?
Cancer causing genes
What do oncogenes promote?
Malignant growth
What do you name tumors based on?
The tissue of origin
Which tumors usually have the suffix “-oma”?
Benign
Which tumors have the suffix “-carcinoma”?
Epithelial origin, malignant
Which tumors have the suffix “-sarcoma”?
Mesenchyme origin, malignant
What kind of tumor is the following?
Adenoma
Benign tumor in glandular epithelium (‘adeno’=glands)
What kind of tumor is the following?
Adenocarcinoma
Malignant tumor in glandular epithelium
What kind of tumor is the following?
Chondroma
Benign cartilage
What kind of tumor is the following?
Chondrosarcoma
Malignant cartilage
How often does a tumor double in size?
Roughly every 120 days (approximately 3x a year - every 4 months)
How long does it take for a tumor to become clinically detectable?
10 years (30 doublings)
How big does a tumor have to be in order for it to be clinically detectable and how is it detected?
1 cm (however exceptions do exist) by a physical exam, chest X-ray etc
