Growth Disorders
An increase in the number of cells in an organ or tissue
Hyperplasia
False: -oma is benign. Sarcoma is malignant (w/ mesenchymal origin). Carcinoma is malignant (w/ epithelial origin)
Define metastasis
Development of secondary malignant growths at a distant site from the primary site of cancer
State the names of the 3 checkpoints in interphase
G2
M
What are the consequences of massive radiation doses on rapidly dividing cells?
Rapid cell death that becomes unable to repair
Clinical consequences:
Early – nausea, vomiting, skin burns, loss of appetite
Late – infections, bleeding, dehydration, confusion
Radiation sickness
Result of acute exposure to high doses of radiation e.g. atomic bomb
Therapeutic ratio = quantitatively defined as ratio between tumour control probability and normal tissue complication probability
Excessive, but focal overgrowth native to a tissue
Harmatoma
What is the general tumour staging system used in Australia?
TNM:
Tumour - Tx to T4
Node - Nx to N3
Metastasis - Mx to M1
How is cancer graded?
Grade 1 (low grade) = the cancer cells look different from normal cells and are usually slow-growing
Grade 2 (intermediate grade) = the cancer cells do not look like normal cells and are growing faster than grade 1 cancer cells
Grade 3 (high grade) = the cancer cells look very different from normal cells and are fast-growing
Mitosis has crossing over and independent assortment?
No - this is meiosis
What are the purines and pyramidines?
Purines: Adenine and Guanin (2 rings)
Pyrimidines: Uracil, thymine, Cytosine (1 ring)
Reversible change where another cell is replaced by another mature cell type
Metaplasia
Differentiate a carcinogen and a mutagen?
Mutagen - causes mutations.
Carcinogens - directly linked to cancer, often due to causing mutations e.g. tobacco.
State the 3 routes cancer can spread
1. haematogenous - blood stream
2. lymph
3. seeding - cavities
State 4 differences between mitosis and meiosis
Cell division 1 vs 2
Haploid vs diploid
Independent assortment and crossing over in meiosis
Gametes vs somatic
State 3 histological features of an apoptotic cell
Apoptotic cells appear as round, deeply basophilic nuclear material (dark purple), highly eosinophilic cytoplasm (pink), cell shrinkage (same size as surrounding RBCs)
Cell shrinkage
Cell condensation
Cell budding
DNA fragmentation
State three features of dysplasia
Pleomorphism – variation in size and shape of cells and nuclei
Abnormal nuclear morphology
Hyperchromatic
Coarse clumped chromatin
Increased nuclear to cytoplasmic ratio
Increased mitotic figures
Define clonality
the expansion of a population of cancer cells from an individual single cell
State preferred metastatic routes of spread for carcinomas, lymphomas, and sarcomas.
1. Haematogenous spread - carcinomas and sarcomas
2. Lymph spread - carcinomas and lymphomas
3. Seeding - sarcomas and lymphomas
What is p53?
a tumour suppressor protein that responds to DNA damage in G1 checkpoint:
Detects DNA damage
Activates transcription of p21 which inhibits CDK-cyclin which prevents transition to S phase
Gives cells time to repair or undergo apoptosis
What triggers the extrinsic apoptotic pathway?
Virally/bacterially infected cell -->
Death ligands (e.g. TNF-alpha and FasL - released by macrophages, CD8+ T cells and NK cells) bind to death receptors on cell = trigger extrinsic apoptotic pathway.
State two microscopic features of BPH
Stromal nodules
Simple columnar epithelium - mimics normal prostate epithelium
Differentiate malformation and neoplasia
Malformation is not neoplastic
Malformation is intrinsic abnormalities occurring during the developmental process
What is CAR T-cell therapy?
an advanced form of immunotherapy that uses a patient's own immune cells (T cells) to fight cancer. It involves modifying T cells in a laboratory to recognise and kill cancer cells, effectively "training" the immune system to attack cancer
Tumour suppressor genes (like p53) need one allele inactivated to lose function
False - need both because it's recessive
This would be true for proto-oncogenes
What caspases are initiated in the intrinsic vs extrinsic pathway?
Extrinsic: Caspase 8 --> 3
Intrinsic: Caspase 9 --> 3
*granzyme/perforin pathway: 10 --> 3