Download Biochemistry of Cancer Cell

Biochemistry of Cancer Cell
Prof.
Taha Kumosani
Prof.
Taha
Kumosani
http://biochemistry4all.com/Taha/5.htm
Cancer: an Overview



Paleopathologists – Dinosaur bones
Egyptians – Papyrus
– Autopsis
Hippocrates – Carcinoma
– Carcinos: Benign tumors
Hemorrhoids
Chronic ulcerations
History of Cancer

Galen, Bichat, Muller, Pasteur, Laonnec, Cohnheim and
Virchow

Theories:



Irritation
Embryonal
Infections
Cancer theories of the 20thCentury



Otto Warburg: abnormal cell respiration
Jesse Greenstein: tumor metabolism
Principal theories of cancer formation:
 Genetic [addition (v), alteration or subtraction (c or r)
 Non genetic
What is Cancer?
•J. Ewing definition:
"Neoplasm: is a relatively autonomous growth of tissue"
•Neoplasm
•Cancer: malignant neoplasm
•Tumor: a general term indicating any abnormal mass or growth of
tissue
Classification
A. Benign tumors
B. Malignant (metastasize, abnormal chromosome number)
Benign tumors: do not spread from their site of origin, e.g.
brain tumor, warts
 Metastasis : a secondary growth originating from the
primary and growing elsewhere in the body

Characteristics of Benign tumours




1. Localized growths respond to body’s
homeostatic controls
2. Encapsulated
3. Stop growing when they meet a boundary
of another tissue
4. Can be destructive
Characteristics of Malignant
1. Have aggressive growth, rapid cell division
outside the normal cell cycle
2. Not under body’s homeostatic controls
3. Cut through surrounding tissues causing
bleeding, inflammation, necrosis (death) of
tissue
Malignant can metastasize
Embryologic Basis of Nomenclature

The suffix "oma" mean tumor
(Exception are the terms, granuloma: a growth of inflammatory
tissue, and hematoma: a mass of blood outside vessels in a tissue)

Benign tumors: tissue(prefix) and (suffix)-oma

Cancers are divided in 2 general categories depending on their embryologic
origin:



Ectodermal cells form skin, its appendages and nerve tissues
(carcinoma)
Mesodermal cells form bone, muscle, cartilage and related
tissues (sarcoma)
Endodermal cells form the intestinal system and its associated
organs (carcinoma)
Example:

Adonocarcinoma [adeno-, glandular (tissue); carcinoma, arising
from endodermal tissue of the stomach, pancreas, or breast]

Caricnosarcoma (indicate that tumor was derived from two
embryonic layers)

Teratoma (indicate that tumor was derived from the three
embryonic layers)
Normal cell cycle
divides
grows
functions
apoptosis death
Apoptosis : programmed cell death that happens in all normal cells,
but not in cancer cells
Cancer cell cycle
divides
grows
immortal
tumor
Growth and Spread

Cancer Growth and Spread




Development of metastasis
Mechanisms of cell invasion
Mechanisms of cancer spread
Immunity to metastasis

Cancer is a label for collection of distinct but related
disease

Characteristics of malignant
1.
Grow rapidly
Invade other tissue
Rarely encapsulated
Contain many abnormal cells of different sizes and shapes
2.
3.
4.
Characteristics of malignant cells
Characteristics of malignant cells
1.
Loss of stickiness
2.
Increased mobility
3.
Proteolytic enzyme
4.
Altered cell surface
Mechanisms of Cancer Spread

Three major routes:
1.
Direct extension or transplantation
2.
Lymphatic system
3.
Blood system
Common cancer sites
 Brain Tumor
 Lung Cancer (Bronchogenic Carcinoma)
 Thyroid Gland Cancer
 Pancreatic Cancer
 Colon and Rectum Cancer
(Colorectal Cancer)
 Breast Cancer
 Uterine Cancer (Endometrial Cancer)
 Ovarian Carcinoma
 Cervical Carcinoma
 Prostate Cancer
 Testicular Cancer (Carcinoma Of The Testes)
 Skin Cancer - Several Types
(Malignant Melanoma)
 Renal Cell Carcinoma
 Squamous Cell Carcinoma
 Leukemia
 Lymphoma
Cancer & Radiation

Cancer – Causing Radiation

Ionizing radiation

Dose – Response : how much Radiation?

Animals studies

Human studies
 Problems in assessing radiation for humans
 How low dose rates affect man

How ionizing radiation induces tumor – still unknown

Public policy toward radiation

Dose and Tissue

Minimum dose in human

Type of Radiation:
Ionizing
Nonionizing
Carcinogens

agents which cause cancer in industrial products
Pesticides
 Water supplies
 Foods
 Cosmetics


% of human cancer caused by environmental
carcinogens

Relation between cancer incidence and types
and different environment around the world

How much cancer is caused by any particular
agents?
Carcinogens Include
- Polycyclic aromatic hydrocarbon
- Aromatic Amines
- Aminoazodyes, dialkylnitrosamine, and alkylating
agents (used in industry as intermediate)
-Natural Products

Aflatoxin, formed by the fungus Aspergillus flavus
Carcinogenicity of Aflatoxin
* Species
* Dose
 Naturally produced chemicals
Miscellaneous
- Inorganic Carcinogenic



Beryllium, Cadmium, Chromium, Nickel and
lead compounds
Radioactive elements such as Uranium, Radium
and Thorium
Asbestos (shape and size)
Cancer and viruses
Virus: is a small infectious agent that can replicate
only inside the living cells of organisms
An oncovirus: is a virus that can cause cancer
Retrovirus enters host cell
What is a hormone?


Hormones are naturally occurring substances
that are produced in specific parts of our bodies
and act as chemical messengers. They travel
through the blood to control the functions of
other tissues and organs
Some of the best known hormones are
estrogen and testosterone. These are known as
‘sex hormones’ and perform a variety of
functions all around our bodies

Hormones affect growth and differentiation

Hormonal imbalance influence the incidence, location
and rate of cancer growth

Hormonal imbalance may be produced by injecting
hormones, explanting or destroying the endocrine gland
or administering hormonal antagonists
What affects our hormone levels?




Reproductive factors
Lifestyle changes
External sources
Drugs that lower hormone levels
Cancer and heredity
Heredity: is the passing of traits to offspring
(from its parent or ancestors).


A hereditary disease is a disease caused by an
abnormality in an individual's DNA which is
inherited genetically
But in some cases the cancer is caused by an
abnormal gene that is being passed along from
generation to generation. Although this is often
referred to as inherited cancer
Why alteration in gene is a problem?
How to identify hereditary cancer?



It is mostly genetic testing that helps one to
assess the hereditary cancer risk
Additionally, identification of gene mutations
also helps other family members to determine
whether they share hereditary cancer risks
Genetic testing is mostly done using blood
Xeroderm pigmentosum
familial polyposis
A molecular basis of cancer
A molecular basis of cancer:

Introduction

Pleiotropy

A genetic basis
Normal Chromosome
Abnormal chromosome
Cancer Cell

Cancer phenotype (total set of structural and functional
characteristics that define a cancer cell) raise important questions

Marguerite Vogt and Renato Dulbecco – California Institute of
Technology
A genetic basis:
* Carcinogens act by damaging DNA and thus causing gene
mutations
* History exp. More than 50 years ago, demonstrated the central
role of DNA as a carrier of genetic information, Oswald and
Colin M.
* Macleod and Maclyn McCarty – Rockefeller Institute for
Medical Research
Affecting cell signalling
• All normal cells receive specific signals that trigger
programmed cell death
• Some chemicals destroy these signals
• As a result the cells do not receive the signals that start cell
death
• Hence they keep growing causing cancer
Destruction of error repair mechanisms:
 Every normal cell has DNA repair genes
 These genes correct any defects that occur sometimes during DNA
replication and cell growth in normal cells
 These genes are called uvr and rep genes
 Some carcinogens affect the repair genes
 As a result, these genes do not function and do not correct errors in
the cell, leading to abnormal growth, division and cancer
Tests and diagnosis
Some important tests for diagnosis
cancer
1.
A process of elimination
2.
The basic tests
3.
Seeing inside by sound and heat
4.
X-rays: new refinements of an old tool
5.
Tracing tumor with hot atoms
6.
The answer in a tissue sample


When initially diagnosed with cancer, a cancer
specialist, an oncologist, will provide you with
the cancer treatment options
He or she will recommend the best treatment
plan based on your type of cancer, how far it has
spread, and other important factors like their age
and general health
Treatments
Chemotherapy
II. Hormaone Therapy
III. Immunotherapy
IV. Growth factor
V. Radiotherapy
VI. Surgery
VII. Natural therapy
I.
Coping with Cancer

A new way to speak

After breast surgery, a normal life and
appearance

Countering the side effects of drugs and rays

How patients help patients
http://biochemistry4all.com/Taha/5.htm