Gan Shermer Flashcards
What is cancer?
Illness resulting from one of our body’s own cells growing out of control
Name the 4 nucleotide bases
Adenine
Guanine
Cytosine
Thymine
How many hydrogen bonds from A to T
2
How many hydrogen bonds from G to C
3
What are codons
Code for amino acids
What is a gene
Sequence of bases that code for a particular protein
What are cancer cells
Product of genetic mutations (changes to the DNA code) that set cells free from the usual controls on cell proliferation and survival
What is metastasis
When cancer cells become detached and move through the bloodstream becoming attached elsewhere
What is apoptosis
Programmed cell death
What is the G 0 phase
Resting phase
Normal cell function
What is the G1 phase
1st growth phase
What is the S phase
Synthesis phase
DNA replication
What is the G2 phase
2nd growth phase
What is the M phase
Mitotic phase
Preparation for cell division
Cytokinesis = cell division
What are proliferation genes
Encode proteins that promote cell division
Tell the cell to leave the G0 and begin cell cycle
What are mutant genes called
Oncogenes
What are antiproliferation genes
Repress the genes that are essential for the continuing of the cell cycle
Inhibit cell division
Couple the cell cycle to DNA damage
What are metastasis suppressor
Proteins involved in cell adhesion that prevent tumours from dispersing
What are apoptosis genes?
Suicide genes Several genes (proteins) involved in controlling cell death when cells are damaged and faulty If these genes are damaged the faulty cell can continue dividing
What are DNA repair genes?
Proteins involved in repairing DNA if it is damaged or wrongly copied
What is TP53
Codes for p53 protein
Can activate DNA repair proteins
Can hold the cell cycle at G1 /S checkpoint to allow for repair
Can initiate apoptosis
What cellular defects are associated with cancer
Tissue invasion and metastasis
Abnormalities in cell cycle division
Evasion of apoptosis
Immortality (limitless cell division)
Abnormal signalling pathways
Insensitivity to growth inhibitory signals
Ability to develop new blood vessels ( angiogenesis)
What anticancer therapies are available
Surgery Chemotherapy Radiation therapy Immunotherapy Hormone therapy Gene therapy
What do chemotherapy strategies rely on and what are the main targets
Cancerous cells reproducing much faster than normal cells
The cell cycle
Angiogenesis
What is intrinsic resistance
Little response to drug
Slow growth rate
Low uptake
What is acquired resistance
Drug sensitive cells killed off leaving drug resistance cells to proliferate
What are alkylating agents?
Highly electrophilic compounds (strong covalent bonds with nucleophiles)
Act directly on nucleic acids
Nitrogen groups in adenine guanine and cytosine
Can also alkylate proteins (poor selectivity)
Can also be mutagenic themselves
What are the general strategies of alkylating agents
Transfer an alkyl group
Attach directly to DNA
Crosslink bases across double helix
What is Busulfan
1,4-butanediol, dimethanesulfonate
Used in chronic myeloid leukaemia
Di mesylate (mesclun group is a good leaving group)
What is cisplatin
Square planar platinum complex
Used in treating lung and ovarian cancers
What are the side effects of cisplatin
Severe nausea and vomiting Nephrotoxicity (kidney damage) Neurotoxicity Ototoxicity Alopecia
What is RNA
Single stranded
Can carry messages to other parts of the cell
Important in transcription and replication
What is tRNA
RNA strand synthesised from DNA template
Info from RNA then used to make amino acids/ proteins
What are antimetabolites
Alkylating agents that act directly on nucleic acids
Act on enzymes (enzymes involved with DNA/nucleotides synthesis)
What is the general action of antimetabolites
Disrupt the cell cycle
Suicide inhibitors - permanently attach to enzymes causing cell death
What are the main types of antimetabolites
Folic acid antagonists
Pyrimidine analogues
Purine analogues
What are topoisomerases
Molecular machines that manage the topological state of the DNA in a cell (how it packs)
What do anti tumour antibiotics work
Target DNA
Cell cycle non-specific
Generally bacteria derived
Important structural components
What are microtubules?
Small tubes
Part of cytoskeleton
Made from Tubulin molecules
Crucial in cell division
What part of the cell cycle do microtubules interact
M phase
What happens in prophase
Chromatin condenses to form chromosomes
Nuclear envelope breaks down
What happens during the prometa and mataphases
Spindles align at opposite ends of the cell
Microtubules attach to the condensed chromosomes and centrosome
Chromosomes align along cell equator
What happens during ana and telophase
Chromosomes separate and are pulled to the poles by shortening microtubules
Nuclear envelope reappears around the separated chromatin
What are the two ways microtubules acts
To stop microtubules from depolymerising hence forcing the cell to remain in the metaphase
To stop tubulin polymerising halts cell cycle in prophase
What are two main classes of anti mitotic drug
Taxanes
Vincas
