Cancer Flashcards
What are the different stages of cancer?
- mutation occurrence, cell divides more than it should
- hyperplasia, cells grow too often, more mutations possible making dividing more rapidly
- dysplasia, looks abnormal now
- in situ cancer, looks very abnormal in growth and appearance, still contained in tissue
- invasive cancer, additional mutations and invades neighbouring tissue cells
What are the hallmarks of cancer? (only important ones marked?
- evading growth suppressors
- enabling replicative immortality
- activating invasions and metastasis
- resisting cell death
- sustaining proliferative signalling
How does cancer enable replicative immortality?
Cancers become immortal by reversing the normal telomere shortening process and instead lengthen their telomeres.
How does cancer resist cell death?
They can deregulate the intrinsic apoptotic pathway, by upregulating BCL-2 proteins and downregulating BHC3 proteins
What are the different stages of metastasis?
- Disruption of cell adhesive mechanisms
- penetration of extracellular matrix, facilitated by metalloproteinases
- Via the lymphatic vessels, it travels. Here it can get stuck > lymph node metastases
- Can get in blood stream and accumulate somewhere else. Micro-metastasis: they die or become dormant > cancer can re-appear years later
Recap: what are the 4 phases of the cell cycle and what are the cyclins involved to initiate this?
- G1-phase (G1 cyclin)
- S-phase (G1-S cyclin)
- G2- phase (S cyclin)
- M-phase (M cyclin)
What is P53?
a protein that acts as a tumour suppressor, regulates cell cycle progression and arrest, DNA repair, senescence and apoptosis.
What is BAX?
A gene that can mediate cell death by apoptosis
Recap: What are the different phases in M-phase?
- prophase
- prometaphase
- metaphase
- anaphase
- telophase
- cytokinesis
What are some risk factors for cancers?
- age > accumulation of DNA mutations
- Hormones > ovarian cancer and thyroid tumour
- infectious agents (HPV)
- sunlight (UV radiation)
- Carcinogens > formaldehyde, DEP, Tobacco)
- DNA mutation > BRCA 1 and 2 gene
What does the two-hit theory for cancer causing state?
The Knudson hypothesis, also known as the two-hit hypothesis, is the hypothesis that most tumor suppressor genes require both alleles to be inactivated, either through mutations or through epigenetic silencing, to cause a phenotypic change.
What are the different treatments of cancer in general?
- chemotherapy (cytotoxic and cytostatic)
- Immunotherapy (clinical trial)
- radiation therapy
- hormone therapy
- hyperthermia
What are the steps in vogelstein model of the process of colorectal cancer?
- mutation APC
- Genomic instability
- mutation K-ras
- mutation DCC
- mutation P53
- other changes
