Cancer And Its Treatments Digital Assignment

1. Cancer and its Treatments
DIGITAL ASSIGNMENT
Cell Biology And Biochemistry
By 17BCB0082
Shivam Kumar Pandey

2. We Will Cover The Following Topics:
• What is Cancer?
• How Does Cancer Spread?
• Various Methods of Treatments

3. What is Cancer?
An abnormal growth of cells which tend to proliferate in an uncontrolled way
and, in some cases, to metastasize (spread). There are more than 100 types of
cancer, including breast cancer, skin cancer, lung cancer, colon cancer, prostate
cancer, and lymphoma. Symptoms vary depending on the type. Cancer
treatment may include chemotherapy, radiation, and/or surgery.

4. Genetic changes that cause cancer can be inherited from our parents. They can
also arise during a person’s lifetime as a result of errors that occur as cells divide
or because of damage to DNA caused by certain environmental exposures.
Cancer-causing environmental exposures include substances, such as the
chemicals in tobacco smoke, and radiation, such as ultraviolet rays from the sun.
In general, cancer cells have more genetic changes, such as mutationsin DNA,
than normal cells. Some of these changes may have nothing to do with the
cancer; they may be the result of the cancer, rather than its cause. The genetic
changes that contribute to cancer tend to affect three main types of genes—
proto-oncogenes, tumor suppressor genes, and DNA repair genes. These
changes are sometimes called “drivers” of cancer. Proto-oncogenes are involved
in normal cell growth and division.

5. However, when these genes are altered in certain ways or are more active than normal,
they may become cancer-causing genes (or oncogenes), allowing cells to grow and
survive when they should not. Tumor suppressor genes are also involved in controlling
cell growth and division. Cells with certain alterations in tumor suppressor genes may
divide in an uncontrolled manner. DNA repair genes are involved in fixing damaged
DNA. Cells with mutations in these genes tend to develop additional mutations in other
genes. Together, these mutations may cause the cells to become cancerous. As
scientists have learned more about the molecular changes that lead to cancer, they
have found that certain mutations commonly occur in many types of cancer. Because of
this, cancers are sometimes characterized by the types of genetic alterations that are
believed to be driving them, not just by where they develop in the body and how the
cancer cells look under the microscope.

6. How Does Cancer Spread?
To understand how cancer treatment works, we have to first understand how it
spreads in our body. A cancer that has spread from the place where it first
started to another place in the body is called metastatic cancer. The process by
which cancer cells spread to other parts of the body is called metastasis. For
example, breast cancer that spreads to and forms metastatic tumor in the lung
is metastatic breast cancer, not lung cancer. Under a microscope, metastatic
cancer cells generally look the same as cells of the original cancer. Moreover,
metastatic cancer cells and cells of the original cancer usually have some
molecular features in common, such as the presence of specific chromosome
changes

7. Various Methods of Treatments:
• DNA Manipulation
• Antimetabolites
• Vinca Alkaloids
• Steroid Hormones
• L-Asparginase

8. DNA Manipulation
DNA, the genetic material of the cell, acts as the selective template for the
production of the specific forms of transfer, ribosomal and messenger
ribonucleic acid (RNA). DNA, in directing the formation of specific sequences of
messenger RNA, determines which proteins (enzymes) will be synthesized on
the RNA templates. The enzymes in turn are responsible for the structure,
metabolic activity, proliferative rate, and function of the cell. Interference with
the structure of DNA (alkylating agents, procarbazine) or its
function(dactinomycin) disorganizes and disrupts the cell. Compounds with this
mechanism of action have been useful anticancer drug.

10. Antimetabolites
Antimetabolites which are incorporated into RNA or act to inhibit protein synthesis
have not proved to be clinically useful in the treatment of cancer Certain
antimetabolites inhibit the biosynthesis of the nucleic acids. Interruption in the
formation of these essential components of DNA and RNA, which each cell produces in
order to function and multiply, results in cell death. Antimetabolites with this
mechanism of action are useful in some forms of cancer. 6-Mercaptopu rifle and 6-
thioguanine® prevent purine ring biosynthesis and interconversion of the purine bases.
Methotrexate® inhibits folic acid reductase to block the reduction of folic acid to
tetrahydrofolic acid which transports single carbon fragments for the synthesis of the
purine ring and for the methylation of deoxyuridylic acid to thymidylic acid, an essential
component of DNA. 5-Fluorouracil® is metabolized to its deoxynucleotide form to
inhibit the enzyme, thymidylate synthetase, which also is involved in the methylation of
deoxyuridylic acid to thymidylic acid; arabinosylcytosine blocks the reduction of
cytidylic to deoxycytidylic acid, and by preventing the formation of another essential
component of DNA, DNA replication is inhibited.

11. Vinca Alkaloids
Other types of drugs used in the treatment of cancer act by different mechanisms. The vinca
alkaloids, vincristine and vinblastine, disorganize the mitotic spindle to arrest cell division. While
these are characteristic effects of the vinca alkaloids, they probably act by another mechanism,
since vincristine differs from vinblastine pharmacologically and therapeutically. Vincristine is
more effective in acute leukaemia and vinblastine in Hodgkin's disease than the other plant
alkaloids, colchicine and its derivatives and podophyllotoxin, which also produce metaphase
arrest. All vinca alkaloids are administered intravenously (IV). They are eventually metabolized
by the liver and excreted.The vinca alkaloids are cytotoxics – they halt the division of cells and
cause cell death. During cell division, vinca alkaloid molecules bind to the building blocks of a
protein called tubulin, inhibiting its formation. Tubulin protein normally works in cells to create
“spindle fibers,” (also called microtubules). These microtubules provide cells with both the
structure and flexibility they need to divide and replicate. Without microtubules, cells cannot
divide. The vinca alkaloid’s mechanism in a nutshell: by occupying tubulin’s building block
structure, vinca alkaloids prevent cancer cells from successfully dividing cells.

13. Steroid Hormones
• Unphysiological doses of exogenously administered steroid hormones alter
hormonal balance in the patient and modify the growth of some cancers
arising from tissues particularly susceptible to hormonal influences. The
mechanism whereby the steroid hormones stimulate or inhibit cellular growth
and function is not clear, but it is believed to be at the level of processes
concerned with RNA to protein synthesis.

14. L-Asparginase
L-asparaginase acts in a unique manner to hydrolyse asparagine to aspartic acid,
and neoplastic cells unable to make this amino acid, die if the supply of L-
asparagine in the circulating blood, on which they are dependent, is destroyed
by the enzyme. Normal cells synthesize L-asparagine for their needs, and thus
appear to be unaffected by the L-asparagine deficiency in the body.