Lecture 7 Flashcards
Another name for tumor
neoplasm
two main groups of neoplasm
benign and malignant neoplasms
malignant tumor from epithelial tissue
carcinoma
malignant tumor from connective tissues
sarcoma
cancer of the blood or bone marrow
leukemia
malignant tumor from melanocytes
melanoma
carcinoma for glandular surface epithelium
adenocarcinoma
how does malignant neoplasm invade locally?
tumor invades the tissues surrounding it by sending out “fingers” of cancerous cells into normal tissue.
Modes of metastasis (3)
- Vascular (veins)
- Lymphatic
- Transcoelomic (across coelomic spaces such as peritoneal or pleural cavities)
Metastasis through vascular
cells grow and break through basal lamina, then invade capillary. Cells adhere to blood vessel wall then escape from blood vessel (estravasation). They proliferates to form metastasis in other organ.
Most of cell proliferation in the body occurs where?
epithelial tissue
Tumor formation (2 types)
- Clonal evolution
- develops through repeated rounds of mutation and proliferation where cells acquire a selective growth advantage over neighbor cells - Stem cell
- tumors contain cancer stem cells which has indefinite proliferative potential
What allows tumor progression?
cells with optimum genetic stability ; if genetic instability is too much, cells will undergo apoptosis, but with optimum genetic instability, they eventually transform into cancer cells
`2 major mechanisms of cell death
necrosis, apoptosis
How do you access necrosis using Propidium Iodide (PI) staining?
PI positive = leaky/discontinuous plasma membrane which means necrosis
How do access necrosis using H&E staining?
increased eosinophilia due to loss of RNA and increase in denatured proteins
variable nuclear staining (loss of nuclei)
increased inflammatory infiltrate
Role of annexin 5 during apoptosis
It binds to phosphatidylserine when exposed on the outer leaflet of plasma membrane
How is DNA fragmentation during apoptosis confirmed?
DNA laddering
what is TUNEL
Assay that detects DNA fragmentation. Fluorescene molecule tags 3’DNA ends.
