Exam I Flashcards
What is Cancer?
1) Uncontrolled cell proliferation
2) Ability to spread
Hypertrophy
Increase in cell sized
Normal organization
Ex: uterine growth in pregnancy and muscle growth with weightlifting
Hyperplasia
Increase in cell #
Normal organization
Hormonal
Compensatory - injury
Pathologic - skin warts
Dysplasia
Disorganized growth
Warning sign
Neoplasia
Disorganized growth
Net increase in # of dividing cells
Neoplasm - Cancer
Cell Differentiation
cells acquire specialized properties that distinguish different types of cells from one another
Road to Cancer
Shift in balance between proliferation and differentiation
Metaplasia
Conversion of one cell type to another
Reversible
Pathological always
Benign
local growth pattern rarely life threatening growth rate usually slow well differentiated Oma
Malignant
Spreads by invasion and metastasis often life threatening growth rate may be rapid differentiation variable carcinoma/sarcoma
Carcinoma
malignant neoplasm of skin and organ cells (85%)
Sarcoma
malignant neoplasm of muscle, bone or connective tissue
Leukemia/Lymphoma
cancers of the blood forming organs leading to proliferation of WBC
Epithelium (Parenchyma)
- Protective covering on all surfaces
2. secretions (function)
Stroma (Connective)
provides blood vessels, lymph for the epithelial (support)
Tumor Grading
cancers of the same type are assigned different numerical grades based on their microscopic appearance
Anaplastic
so poorly differentiated and abnormal in appearance and organization that it bears little resemblance to the cells of the tissue in which the tumor arose
Tumor Staging
Tumor (X, 0, is, 1,2,3,4)
Lymph Nodes (X, 0, 1,2,3)
Metastasis (X, 0, 1)
DNA Microarray Analysis
technique that allows the activity of thousands of genes to be measured simultaneously; looks at tumors that appear to be identical and subdivides them into groups based on differing patterns of gene expression
Cachexia
Life-threatening condition characterized by extensive weight loss, weakness and malnutrition
Normal Cells v. Cancer cells
- Anchorage Independent
- Decreased Density-Dependent Inhibition of Growth
- Limitless Replicative Potential (Activated Gene for Telomerase)
- Tumorigenicity when injected in lab animals
Functions of ECM
Support
Adhesion
Movement
Regulation
Anoikis
Apoptotic death triggered by lack of ECM contact
Growth Factor Independence
- make their own GF
- mutant receptors that are permanently activated (no longer require ligand)
- Hyperactive proteins involved in relaying signal
Cell Cycle Clock
master governor operates in the cell nucleus that decides the cell’s fate from outside input
DNA synthesis
only in S phase
Cell growth vs. Cell proliferation
increase in size vs. cell division
Checkpoints
RP in G1
DNA damage cp in G1, S, G2
Spindle cp in M
Cyclins
group of proteins that activate CDKs that are involved in regulating progression through cell cycle
Regulatory component
Cyclin Dependent Kinase
Inactive as monomers; active only after binding to cyclin partner
Catalytic component
Cyclin circulation
D in G1
E after RP
A in S and G2
B in M
CDK Inhibitors
D - p15, p16, p18, p19
E, A, B - p57, p27, p21
Retinoblastoma
Phosphoprotein that functions as a dimer with transcription factor E2F
Phosphorylated Rb allows G1 to proceed to S; releases E2F transcription factor
Extrinsic Apoptosis
External signal to death receptors turns Procaspase into active Caspase
Death ligands > FADD protein > Caspase 8 or 10
Intrinsic Apoptosis
Often in response to DNA damage > p53 > death-promoting proteins > removal of Bcl2 from mitochondria surface which releases Cytochrome C
Caspase 9
Caspases
proteases that activate signaling cascade to induce apoptosis
Most common types of spontaneous mutations are cause by…
Interactions between DNA and water molecules
Depurination
Deamination
DNA Repair Mechanisms
- Translesion Synthesis and Excision Repair: abnormal bases
- Mismatch Repair: mismatched bases
- Non-Homologus End-Joining and Homologous Recombination: double stranded DNA breaks