Example research essay topic: Abnormal Cell Growth Leading To Cancer – 1,599 words

Cancer is the second leading cause of death in the
United States. Half of all men and one-third of
all women in the U.S. will develop cancer during
their lifetimes. Although it is common knowledge
that cancer is generally inherited, this paper
will further explore the causes and what happens
on a cellular level when cancer develops in the
human body. Basics of signal transduction Cell
communication, or signal transduction, is simply
the means by which cells in the body respond to
signals coming from outside those cells. The
purpose of this chemical communication is to
coordinate functions inside the cell, between
cells or between organs in the body, allowing us
the means to respond to our external environment.
Normally, cell division is a very carefully
regulated process that ensures the body has
neither too few nor too many of a given cell type.
Some cell types in the body wear out quickly and
need to be continuously replaced as they die, such
as most blood cells and cells lining the digestive
tract.

The production of these cells must be
precisely regulated based on their rate of cell
death so that the body has the exact number of
cells it needs. (Kruh, 2000) The relationship with
cancer Abnormal – or more specifically –
uncontrolled, rapid cell growth is a central
feature of cancer. Virtually every cancer is
caused by mutations of DNA, the genetic material
that controls how cells behave. Genes that
regulate cell division are most susceptible to
mutations, which may lead to abnormal cell growth.
Cancer is a disease of the genes – it arises from
defects in certain genes, the genes that normally
regulate cell growth and cell death. Some genes,
known as oncogenes, promote normal cell growth.
Other genes, known as tumor suppressor genes, have
the opposite effect, to retard cell growth. The
normal division of our cells is a delicate balance
of positive and negative growth signals from these
genes.

This balance may be upset by either the
abnormal over activation of oncogenes or the
abnormal inactivation of tumor suppressor genes.
These genetic events may be caused by
environmental toxins, random internal changes, and
also may be inherited from a family who has a
history of cancer where a defective
growth-regulatory gene is passed down through
generations. Cell division can get out of control
when damage to specific genes in the cells DNA
results in abnormally functioning growth
regulatory proteins. For instance, melanoma is a
cancer that arises in the melanocytes, the cells
that produce melanin. The primary cause of
melanoma is damage to the DNA of melanocytes by UV
radiation from the sun. When we are overexposed to
the sun and receive too much UV radiation, the DNA
may be damaged, thus resulting in abnormal cell
growth and eventually, cancer. When a cell becomes
cancerous, over time a tumor forms from these
abnormal cells.

Because the tumor is made up of
defective cells, it cannot function as it should.
The body suffers in two ways: from both the loss
of the normal function of that tissue and from the
damage to other tissues. Tumors can invade and
destroy nearby tissue. Some tumors secrete
hormones or enzymes that disrupt the bodys normal
functions. As tumors grow, they develop networks
of blood vessels and begin robbing the body of
essential nutrients. Eventually, cells may break
away from the tumor and spread to other parts of
the body, when they establish tumor colonies. This
spread of cancer is called metastasis.

New
research by scientists at Emory University in
Atlanta, Georgia sheds light on a new class of
enzymes that may be active in cancer. The enzymes
convert oxygen to a destruction form called
reactive oxygen and appear to play a role in
abnormal cell growth. Reactive oxygen has been
associated with damage to cells as well as damage
to DNA. Mox1, a member of the new class of
enzymes, was found to be a growth promoter for
cells by producing the reactive oxygen. The oxygen
in turn causes the cells to divide quicker than
normal. When the Mox1 gene was inserted into mice
cells, the cells began to divide more quickly
taking on characteristics of abnormal cells.

When
these cells were inserted into mice, tumors
resulted. (Coleman, 2001) Types of cancer Cancers
are grouped into the following categories: Carcinomas Melanomas Lymphomas Sarcomas
Carcinomas, such as lung cancer, breast cancer,
colon cancer, and prostate cancer, are by far the
most common group and account for over 90 percent
of all cancer cases. Carcinomas arise from the
cells that comprise the inner linings of organs
and the glands of the body. Melanomas, making up
about four percent of all cancers, stem from the
pigment-forming cells in the skin. Lymphomas are
less common and account for about five percent of
all cancer cases. This group arises from cells of
the blood, bone marrow, and immune system.
Sarcomas are the least common group and account
for only one percent of all malignancies.

These
tumors arise from the skeletal and connective
tissues such as cartilage, bone and muscle. Drugs
that fight cancer The use of drugs to treat cancer
is called chemotherapy. The general aim of
chemotherapy is to decrease the growth rate of
cancer cells. Chemotherapy drugs that are
effective in treating cancer interfere with the
activity of cancer cells, either by directly
sabotaging a specific phase of cell development or
by sending confusing messages to the cells, thus
causing them to act the wrong way and ultimately
destroy themselves. They are usually administered
orally or intravenously. In general, chemotherapy
drugs can be divided into three main categories
based on their goals: 1.

Directly damage the DNA
in the cancer cell nucleus These drugs chemically
damage DNA by disrupting replication and either
totally halt replication or cause the manufacture
of nonsense DNA that does not code anything
useful. Examples of drugs in this class include
cisplatin (Platinol), daunorubicin (Cerubidine),
doxorubicin (Adriamycin) and etoposide (VePesid).
This is an example of an aklylating agent, which
affects cancer cells in all phases of their life
cycle and confuses the DNA by directly reacting
with it. 2. Stop the synthesis of new DNA strands
to stop the cell from replicating which allows the
tumor to grow These agents stop the production of
new DNA strands by blocking the formation of
nucleotides or deoxyribonucleotides, which are the
building blocks of DNA and RNA. Examples of drugs
are methotrexate (Abitrexate), mercaptopurine
(Purinethol), fluorouracil (Adrucil), and
hydroxyurea (Hydrea). These are examples of
antimetabolites, which interfere with the cells
ability for normal metabolism.

These are
phase-specific drugs – they work in one phase of
the cells life cycle. 3. Stop cancer cell mitosis
by breaking down or disrupting the mitotic
spindles Mitotic spindles are like molecular
railroads that are like the north and south poles
in the cell when a cell starts to divide itself
into two new cells. They help to split the newly
copied DNA that goes into the new cells during
cell division. These agents disrupt or stop the
formation of these spindles and interrupt cell
division as a result. Examples of drugs include
Vinblastine (Velban), Vincristine (Oncovin), and
Pacitaxel (Taxol).

(Langerak, 2001) Side effects
of chemotherapy Chemotherapy drugs doses and
schedules are developed so that the drugs enter
the body, kill the rapidly dividing cancer cells,
and are expelled before they can damage most
healthy cells. The majority of drugs currently on
the market are not specific, which leads to the
many common side effects associated with cancer
chemotherapy. Since the goal of chemotherapy is to
decrease the growth of cancer cells, the side
effects are seen in bodily systems that naturally
have a rapid turnover of cells, such as white
blood cells, hair follicle cells, and cells lining
the gastrointestinal tract. These normal cells
also end up damaged by the chemotherapy. Common
side effects include: Dry, flaky skin and mouth
sores (when skin and mouth cells are damaged) Loss of hair (when hair cells are damaged) Nausea
and vomiting and appetite changes (when stomach
and intestine cells are damaged) Blood clotting
problems (when bone marrow cells are damaged,
interrupting normal platelet production) Compromised immune system making it more difficult
to fight infections (when white blood cells are
destroyed by the chemotherapy) Possible sterility
(when the reproductive organs are damaged) Anemia
(when damaged bone marrow cells cannot produce
enough red blood cells, causing fatigue) Decreased sexual desire (when hormones are
affected by the drugs) The severity and presence
of side effects differ from person to person.
Individuals also have different reactions with
each treatment. (McKinnell, 1998) Conclusion
Through chemotherapy and the use of other drugs
that directly affect the body on a cellular level,
many cancer patients are able to carry on happy
and fulfilling lives.

The focus now is not so much
curing the symptoms of cancer, as it was before,
but dealing with the source and root of the origin
of cancer, which demands that we learn more about
what happens inside our bodies and how our cells
function. Although our knowledge of signal
transduction is still limited, it is nevertheless
widely accepted that the more we discover and know
about how cells communicate with each other and
grow, the closer we come to finding the ultimate
cure for the deadly cancer. References Coleman,
William B., Tsongalis, Gregory J. 2001, The
Molecular Basis of Human Cancer, Humana Press.
Kruh, Gary D., Tew, Kenneth D. 2000, Basic Science
of Cancer. Current Medicine.

Langerak, Alan D.,
Dreisbach, Luke P. 2001, Chemotherapy Regimens and
Cancer Care. Landes Bioscience. McKinnell, Robert
Gilmore, Parchment, Ralph E., Pierce, G. Barry.
1998, The Biological Basis of Cancer. Cambridge
University Press..

Research essay sample on Abnormal Cell Growth Leading To Cancer