Cancer Flashcards
Describe some things that contribute to cancer
- Cancers are as a result of the interaction of genetics, epigenetics and environment of the individual.
cancer cells are able to multiply and spread without biological restraint, damage to DNA and mutations in these genes allow unregulated growth - Cancer is also suggested to be due to mitochondrial failure which in turn is due to:
– Lack of oxygen and nutrients.
– Toxins, esp. those that interfere with mitochondrial biochemistry.
– Stress
– Leading on to cellular defects and then to mutated genes such as Tumour Protein p53 etc.
Which cellular changes happen with cancer? ( with apoptosis detail)
Self-sufficiency in growth signals (self-renewal).
* Insensitivity to anti-growth signals.
* Limitless replicative potential.
* Evasion of apoptosis- plays a role in homeostasis and normal development, dysregulation of apoptosis is critical to tumour cell survival
* Ability to produce sustained angiogenesis.
* Ability to invade and metastasise.
What are oncogenes and what makes them more acttive?
Oncogenes are genes that code for one of the typical
behaviours of cancer cells: growth, non-responsiveness to
stop signals, failure of apoptosis, invasion, metastasis.
- Oncogenes become active:
– By a mutation that makes them constitutively active (may be inherited).
– By epigenetic modifications such that a gene which is normally silenced becomes active (usually due to loss of methylation
marks).
Describe the cancer volcano
Cellular oxidative damage leads to….
Gene mutation….
Change in cell cycle…
cell mitosis….
Production of oncoproteins …
low level of fat and water soluble antioxidants
low natural killer cell function
Describe some dietary carcinogens/ progression promoters
1) Aflatoxins (found in mouldy food).
2) Heterocyclic amines (meat cooked at very high temperatures).harmful carbon
compounds such as pyrolysates and amino acids which have a strong cancerous effect
3) N-nitroso compounds (in some spoiled foods, protein foods, cured meat).
4) Polycyclic aromatic hydrocarbons (PAH) (products of combustion found in cooked foods, smoked foods and dark beer).
Progression Promoters
1) Excess & damaged fat: Creates lipid peroxides and oxygen radicals further damaging DNA.
2) Excess protein: Increases IGF-1, promotes further cancer cell growth.
3) Excess omega 6: Inflammation promotes further cancer growth
4) Heavy consumption of red meat
5) Saturated fatty acids, trans fatty acids and refined sugars, induce frequent postprandial hyperglycemia, decreasing IS
6) Sodium Chloride NaCl. increase the risk of stomach cancer (Japan and portugal)
7) Artificial Sweeteners
* High levels of aspartame have been found in brain tumours. During metabolism, the methyl group of the aspartame is converted to highly toxic substance formaldehyde, causes severe damage to the nervous and immune systems and permanent genetic damage.
Describe fat types and their role in tumour promotion
1) Saturated fat (SFA): positive correlation.
2) Polyunsaturated fat (PUFA): Excess PUFAs promote tumourigenesis, Omega 3 PUFA: Protection and promotion in some studies
3) Monounsaturated Fat (MUFA): Research inconclusive; however,excess linked to higher cancer risk.
4) Trans fat: effects on tumorigenesis.
How can poorly controlled blood glucose poison the body?
- Increased oxidation, premature ageing, destruction of tissue
- lowered immunity and infections
- increased insulin increases IGF-1 and PGE-2
- Glycosylated proteins, loss of flexibility and absorption in many cells
How can cooking result in dietary carcinogens?
Grilling, frying and barbecuing protein-rich foods:
– Polycyclic aromatic hydrocarbons (PAHs) and heterocyclic
amines (HCAs) found in grilled fish and meat mostly.
– N-nitroso compounds in grilled cured products are approximately 5x higher than in uncooked products.
– Acrylamides: Starchy foods baked or fired at high temperatures (chips, crisps, sugar- coated breakfast cereals).
Why is obesity implicated in cancer, and which types is it common in?
1) Excess body fat changes hormone metabolism- higher oestrogen levels, more oestrogen stimulation , stimulates cell proliferation , leading to a more rapid growth of
oestrogen-responsive breast tumours.
2) promotes oxidative DNA damage.
3) Leptin leads to cell proliferation, facilitates alteration in carcinogens.
4) changes insulin metabolism- excess insulin leads to increased IGF-1 , which stimulates cell division
5) negatively affects the immune system
6) inflammation promotes angiogenesis and cell proliferation
Increases risk of Colorectal, Breast and Endometrial cancer
How do phyochemicals play a role in cancer protection?
Phytochemicals:
– inhibiting the formation of a carcinogen from precursor substances.
– Increasing metabolic detoxification of carcinogens.
– Preventing carcinogens from interacting with DNA and RNA
How is fibre protective in cancer?
Diets high in fibre are protective against several types of cancer:
1) Increases transit time and decreases exposure to carcinogens
2) Reduction in serum oestrogen concentration
3) Dilutes bile acids, believed to promote
colon carcinogenesis.
4) reduces insulin levels
- It is possible that the major benefits come from the phytochemicals in the fruits, vegetables and whole grains which are found alongside the fibre.
Discuss how a vegan diet may be protective in cancer?
1) A low-fat vegan diet increases the protein that binds
excess oestrogens - sex hormone binding globulin
(SHBG) - , reducing the free oestrogens and thus their ability to stimulate existing tumours.
2) A low fat vegan diet is anti-inflammatory- reduces
marker C-reactive protein.
3) PSA levels - a marker that tracks prostate cancer growth - decreased by 4 percent after one year on a low-fat vegan diet,
4)Full of antioxidants, promotes synthesis
of detoxification enzymes
5) Lowers insulin
6) Lowers AGE,
oxidative damage
7) Minimizes carcinogen exposure
Describe the Gerson therapy
- organically grown fresh fruits and vegetables and thirteen glasses of freshly squeezed juices daily, taken at hourly intervals= high levels of vitamin C, beta-carotene and other antioxidants
- The key detoxification method is the coffee enema, Caffeine taken rectally is believed to stimulate the action of the liver, increase bile flow, and open the bile ducts so
that the liver can excrete the toxic products of tumour breakdown more easily.
Why are antioxidants important for cancer, describe the effects of A C and E?
Describe some immune enhancing nutrients?
Coenzyme Q10: Enhances natural killer cell and T cell activity. increases cellular production of energy and prevents cellular damage by neutralising free radicals.
- Curcumin: enhances the phagocytic activities of macrophages, inhibits the production of inflammatory cytokines that stimulate tumour growth.
- Flavonoids: stimulate natural killer cells and inhibit critical enzymes that direct the inflammatory response - reduce inflammation and inhibit tumour growth.
Garlic: Enhances natural killer cell function and may increase tumour cells ‘antigenicity.
- Green tea: Promotes repair to DNA and encourages apoptosis of damaged cells. anti-angiogenesis properties,
- Indole-3-carbinol: An antioxidant, neutralises free radicals. I(HPV). Stops cancer cells growing and increases death rate
of cancer cells. Restores p21 gene preventing synthesis of DNA for new cancer cells. Converts highly active oestrogen variants into safer oestrone.
Lycopene: increases NK cells.
- Melatonin: Increases cytotoxic activity of lymphocytes and helps prevent chemotherapy- and radiotherapy- induced bone marrow suppression.
- Mushroom polysaccharides: Stimulate lymphocytes and NK cells to secrete cytotoxins and interferon which activate immune-mediated totoxicity.
- Resveratrol: Fights yeast and fungal growth, protects and repairs DNA, kills cancer cells, prevents metastasis.
