Transcript Role of Vitamin E & C in cancer prevention and therapy

CANCER: ROLE OF VITAMIN
C AND E IN THERAPY
Gandhari , Aditi, Divya, Ankita
CANCER
Occurrence of cancer
Mortality rates
What is Cancer?
Cancer is a class of diseases in which a group of cells
display uncontrolled growth, invasion and sometimes
metastasis .
Causes
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Mutation: chemical carcinogens, liver cancer by aflatoxin b
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Mutation: ionizing radiation, skin cancer
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Viral infection, cervical cancer
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Bacterial infection, gastric lymphomas
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Hormonal imbalances, endometrial cancer
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Immune system dysfunction, sarcoma
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Heredity, breast cancer
Stages of cancer
Properties of a cancerous cell
Mechanisms used by cancer cells
Mechanism of cancer formation
Cancers are caused by a series of
mutations
 There are two broad categories of
genes which are affected by these
changes
• Oncogenes
• Tumor suppressor genes
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TREATMENT
Surgery
Chemotherapy
Radiation therapy
Surgery
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Is the removal of the cancer cell mass
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Not a very effective & successful cure
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followed by chemo or radiation therapy
Chemotherapy
It refers to antineoplastic drugs used to treat cancer.
Types of Chemotherapeutic Drugs
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Alkylating agents: Cisplatin, cyclophosphamide
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Antimetabolites: mercaptopurine
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Plant alkaloids: vinca-alkaloids
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Topoisomerase inhibitors: etoposide
Chemotherapy drug targets
Kinetics of tumor growth
Side effects of Chemotherapy
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Depression of the immune system
Fatigue – severe or mild anemia
Tendency to bleed easily
Gastrointestinal distress – nausea and vomiting
Hair loss
The development of secondary neoplasia
Radiation Therapy
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High energy rays
X rays
Gamma rays
Particle beams
Proton beams
Neutron beams
Destroy cancer cells & keep them from reproducing
Two types of radiation therapy
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External radiation
therapy – radiations
incident from outside.
Internal radiation
therapy – radioactive
source inside body.
The radiation – units
are Gray (1joule/kg)
and Sievert
(1joule/kg).
Drawbacks of radiation therapy
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Kills normal cells also.
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Fatigue and skin irritation.
Fibrosis - Tissues become less elastic over time due to a
diffuse scarring process.
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Secondary cancer
Need for improved treatment
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Destructive effect of radiation and/or chemotherapy
on normal cells in addition to cancer cells.
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Dose limiting toxicity of these treatments.
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Numerous side effects of chemotherapy.
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Need for selective destruction of cancer cells.
VITAMIN C & E
IN CANCER PREVENTION AND TREATMENT
Therapeutic effect of Vitamin C
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Important raw material for the development of
immune system cells.
Generates and mobilizes specialized cells that fight
cancer and infections.
Crucial first line of defense against mutated cells
Vitamin supplement in diet of patient
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Increases tolerance to radiation therapy
– radioprotection to normal cells
Enhances tumor destruction
– radiosensitization of cancer cells
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Upregulation of immune system
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Prevents glucose raising effects of chemo drugs
Vitamin C improved survival rates
Therapeutic effects of Vitamins E & C
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Inhibition of cancer by the quenching of free radicals
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Direct effect on tumor cells induction of differentiation
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Cell cycle inhibition & induction of apoptosis
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Enhanced immune system response to tumors
Production of free radicals
H2O
h
Lipid peroxidation
R-OH + .O-O-H
.O
+ .OH + H3O+ +
Osinglet + .O-O-H
R-O-O. +H2O
Oxidative stress
Vitamin E and C as antioxidants
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Conventional knowledge – prevent DNA damage to
some extent.
Inhibit cancer formation by scavenging reactive
oxygen or nitrogen species essential for HIF-1 protein.
Functions of HIF-1
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Free radicals dependent
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Important for survival of growing tumors as –
Converts sugar to energy
Constructs new blood vessels
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Antioxidants remove free radical – HIF-1 disabled
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Chemistry of vitamin C
2R`+
+2R-H
Ascorbic acid
Dehydroascorbic acid
Chemistry of vitamin E
Dimerises & excreted
Vitamin E succinate induced apoptosis
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Transforming growth factor-ß signaling pathway
Fas/APO-1/CD95 signaling pathway
Mitogen-activated protein kinase signaling pathway
growth inhibition and
apoptosis
death receptor
VES upregulates
TGFβ receptos
Cancer cell
downregulates it
MAP
kinase
cascade
Receptor mediated
pathway of
apoptosis
Pathway by which
TGFβ functions in a
normal cell
Summary
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Cancer - cells with uncontrolled growth & metastasis.
Caused by mutations in the genes.
Treated in multisteps clubbing various treatments.
Vitamin C & E
reduce side effects of radiation and chemo therapy.
Upregulate immune system.
Inhibit functioning of HIF-1 protein.
VES is known to cause apoptosis in cancer cells.
Cancer can be prevented
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Healthy diet rich in oxidants.
Decrease intake of too much fried food.
Exercise regularly.
Reduce stress levels.
References
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CELL AND MOLECULAR BIOLOGY- GERALD KARP
SCIENCE DAILY
PUBMED
AMERICAN CANCER SOCIETY
INMAS RESEARCH PAPERS
WIKIPEDIA
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