Cancer

1. CANCER

2. CANCER
Abnormal faster growth of some tissues
is called as cancer.
They use all food of body.
They first damage the organ and then
entire body.
The cancer cells do not have definite life
span.
They divide until the body dies.
They do not have proteins regulating
cell division due to gene mutation.

3. TYPES OF CANCER
Sarcoma – Cancer in muscles,
cartilage, bones, blood vessels,
connective tissues.
Carcinoma – Cancer in skin or linings
of internal organs.
Lymphoma – Cancer in lymph glands
or lymph nodes.
Leukaemia – Cancer in blood
forming organs specially bone
marrow.

4. TYPES OF TUMERS
Benign Tumour :- Enclosed in
connective tissue, localised to
particular part of body.
Malignant Tumours :- Spread to
different parts of body called
metastasis.

5. TYPES OF TUMOURS
Benign Tumour :- Enclosed in
connective tissue, localised to
particular part of body.
Malignant Tumours :- Spread to
different parts of body called
metastasis.

6. CAUSES OF CANCER
Point mutation / mutation
Telomerase and cancer
Oncogenes
Protooncogenes
Tumour suppressor genes
Carcinogens – Dyes, chemicals, heavy
metals.
Excessive smoking / alcoholism Chewing
tobacco, betel nuts.
Ionic radiations as X-ray, gamma ray etc.
Pollutants as dust, smoke, chemicals etc.

7. Point mutation / mutation
A mutation in gene encoding for
protein regulating cell division causes
cancer.
It may be alteration of single
nucleotide (point mutation) or more
nucleotides (mutation).
e. g. – in case of ras induced bladder
cancer – change of a single Guanine
base with Thymine base can form
valine in place of glycine in the protein.

8. Telomerase and cancer
 Telomerases are short sequences of
nucleotides, repeated thousands of times on
ends of chromosomes.
 As DNA polymerase is unable to copy entire
chromosome, telomerasses are lost on every
cell division.
 This inhibition of telomerase replication is
very effective break on cell division.
 Any mutation, releasing telomerase inhibitor,
release this break and cause cancer.
 e. g. – in human, ovarian tumour cells
telomerase inhibitor is found.

9. Oncogenes
 Oncogenes are cancer causing genes.
 e. g. – ras and myc genes. Expression of myc
gene form Cyclins and Cyclin-dependent
protein kinases (Cdks) but oncogene
mutation stop myc activation.
Protooncogenes
 Oncogenes of acute transforming
retroviruses have homologous counterparts
in animal genomes called proto-oncogenes.
 They participate in normal cell function.
 A mutation or abarrant activation of
protooncogene causes tumour formation.

10. Tumour suppressor genes
 In normal cells, cell division is switched off
by proteins that prevent binding of cyclins to
Cdks.
 The genes coding these proteins are called as
Tumour Suppressor genes.
 Their mutant alleles are genetically recessive.
 e. g. – Rb proteins, p16, p21, and p53
proteins.
Carcinogens – These are cancer causing
agents such as Dyes, chemicals, heavy
metals, pollutants, dust etc..

11. Excessive smoking / alcoholism Chewing
tobacco, betel nuts
 About one third of world cancer is caused by
cigarette smoking.
 Active smoking – smoker himself / herself.
 Passive smoking – persons near smoker.
 Tertiary smoker – when some parts of
cigarette or tobacco fall on ground and
accidentally inhaled or ingested by others.
 Tobacco smoke contain about 3000 chemical
components, most are mutagens for cancer.
 Example is in the next slide :-

12.  E. g. – Benzopyrene (BP) is a potent mutagen
in tobacco smoke. Lungs cells absorb BP and
chemically alter it into a derivative
Benzopyrene-diolepoxide (BPDE). BPDE
binds to tumour suppressor gene p53 and
mutate and hence inactivate it. P53 coding
for a protein to control G1 phase of cell cycle,
which is not coded by mutant. This
inactivation of p53 cause about 70% of lung
cancer.
 Ionic radiations as X-ray, gamma ray etc. –
They may induce mutation and cause cancer.

13. Persistently growing mole or wart.
A thickening or hard part or lump in any
body part.
Persistent cough or hoarseness.
Difficulty in swallowing.
Persistent changing bowel movement.
Unusual bleeding.
Weight loss without any specific cause.
POSSIBLE SYMPTOMS OF CANCER

14.  Biopsy of suspected tissue – (Taking a small sample
from any part of body for microscopic examination).
 Study of blood and bone marrow sample
 Microscopic examination of body fluids
 Radiography
 CT scan – Computerised Tomography
 Magnetic Resonance Imaging.
 Antibodies against cancer specific antigens are used
for certain cancer detection.
 Transfection is a technique to isolate nuclear DNA
from tumour cells and cleaving it into fragments.
Each fragment is than individually tested to induce
cancer into assimilated cells.
DIAGNOSIS OF CANCER

15.  Cancer cells - Grow through the walls of
blood vessels.
 Carried by blood to other parts of body.
 Pass through lymph vessels and lymph
glands.
 Spread from tissue to tissue.
TRANSMISSION OF CANCER

16. Preventing initiation of Cancer
Preventing spread of cancer
Therapies
Surgery
Radiotherapy
Chemotherapy
Immunotherapy
TREATMENT OF CANCER

17. To check Growth factor, it is a protein
carrying the dividing signal for cells.
Relay signal or entry of signal into cell
interior by a muted protein Ras protein.
Amplification of signal in cytoplasm by
anti-sense RNA.
Removal of break of cell division.
Integrity of cell DNA by tumour
suppressor protein p53.
PREVENTING INITIATIION OF CANCER

18. Formation of small blood vessels to
supply tumours is called angiogenesis.
Angiogenesis inhibitors as angiostatin or
endostatin inhibit this and regress
tumours to microscopic size.
Preventing metastasis by inhibiting RhoC,
a GTP hydrolysing enzyme ( it favours
migration of cells by providing needed
GTP ).
PREVENTING SPREAD OF CANCER

19. Surgery :- Removal of cancerous parts by
surgery.
Radiotherapy :- Cancerous cells are killed
by irradiation.
Chemotherapy :- Cancerous cells are
killed by some chemicals.
Immunotherapy :- Body’s immune system
is activated against cancer by use of
monoclonal antibodies.
THERAPIES FOR TREATING CANCER