Ryan Mulcahy
Out of control cell division.
This assignment will discuss the relationship between the cell cycle, cell-division and
cancer. Within this assignment, the author will be showing an understanding of
tumour suppressor genes and proto-oncogenes in controlling cell division; the word
tumour will be defined. Furthermore, the author will be discussing the differences
between benign and malignant tumours. This will then be finalised about how drugs
can be used to treat cancer, and how this treatment can impact on cell division.
Cancer is a disease that is caused by uncontrolled cell division. This development
can progress due to a variety of changes within the activity of the cell cycle
regulators (Khan Academy, 2018). Inhibitors are there to stop cells from dividing
when the conditions are not right; little activity from the inhibitors can prompt cancer
to arise, these are known as mitotic inhibitors. However, cancer can form when the
inhibitors become too active; these changes in activity are due to the mutations
within the genes that code cell cycle proteins. The mutation in genes can be caused
by an increase of cell division rates on the system; this could be cell cycle arrest or
programmed cell death (Khan Academy, 2018).
Cancer cells act as independent cells, they will continue to grow without control, if a
mass of cancerous cells begin to grow, it can then further develop into a tumour;
tumours will form in a number of stages (Learner.org 2018).
During the second stage, abnormal changes will occur within cells; cells look
abnormal under a microscope but are not cancerous; within this stage, nuclear
membranes are irregular, chromatin is coarse, nucleoli are prominent
(Sciencedirect.com, 2018). The third stage comes with more abnormal cells and this
can spread to a greater area of tissue. Results of this can cause the cells to lose
their original function; these cells are named anaplastic. Once the tumour has
reached this stage, it will continue to grow within its situ; it is not invasive and is not
considered malignant, it is potentially malignant (Learner.org 2018). The final stage
will occur when cells in the tumour reaches metastasis, meaning that it can then
spread to more tissues, including the bloodstream. Tumours at this stage are the
most serious (Learner.org 2018).
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, Ryan Mulcahy
There are cell cycle checkpoints known as G1 and G2, these are essential in
preventing the cell to proceed into the next phase prematurely. If this did occur, then
this could result with great consequences for the cell and cell death
(Sciencedirect.com, 2018).
There is a difference between malignant and benign tumours. Malignant tumours
have the capacity to spread towards other tissue cells in different parts of the body.
To travel to different locations, they must break off from the situ of the tumour and
enter the bloodstream or lymph system (Cancer.org, 2018).
Whereas, benign tumours cannot; however, they are known as aggressive as they
can deteriorate nearby bones and soft tissues (Sacoma.Org, 2018).
Proto-oncogenes produce protein produces that will enhance cell division or enable
cell death. If a proto-oncogene becomes mutated, this will then turn to oncogenes.
(Cancer.org, 2018). These can process proteins that stimulate cell division and also
maintain apoptosis. Proto-oncogenes are vital for cell growth and development that
maintain organs and tissues. A mutated version of this is known as an oncogene;
these increase mass production of proteins which will lead to uncontrolled cell
division. Common features that will define cancerous cells have a slow rate of
differentiation and increased inhibition of apoptosis (Robertson, 2018).
Tumour suppressor genes are normal cells that slow down the process of cell
division, they also repair mistakes made in DNA and can process apoptosis; this is
when cell(s) become abnormal and is programmed for cell death. Cell death is
essential for normal development of cells and the cell cycle. It is also vital in the
upkeep of normal cell regulations (Andrew G Renehan, 2018). If a tumour
suppressor gene begins to malfunction, this can cause cells to grow out of control
which can result in cancer (Cancer.org, 2018). P53 is a gene that regulates a protein
in the cell cycle; this can act as a tumour suppressor. It is essential for cells to
suppress cancer; P53 has a great role in preserving its stability by preventing gene
mutation (Shahbazi, 2018). If the gene P53 is damaged then the suppression for
tumours will be decreased. This gene can become damaged by mutations; such as
viruses and radiation. This will increase the possibility that uncontrolled cell division
will begin “more than 50 percent of human tumours contain a mutation or deletion of
the p53 gene” (Bioinformatics.org, 2018).
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