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regulatory proteins control the progression through
these phases, ensuring that each step is completed
accurately before moving on to the next.
P53: One of the most critical proteins involved in regulating

The Guardian the cell cycle is p53, so much so that p53 was actually
named the molecule of the year in 1993! P53 performs
several vital functions to maintain cellular integrity and
of the genome prevent cancer development. When DNA damage is
detected, p53 is activated and can halt the cell cycle
at the G1 checkpoint by promoting the expression of
p21, a cyclin-dependent kinase (cdk) inhibitor that
Have you ever wondered how cancer develops and prevents the cell cycle from progressing. This ensures
how our bodies manage to avoid it most of the time? that cells with damaged DNA do not continue to divide,
Well, today we are going to explore the functions of a thereby reducing the risk of tumor formation. Once the
very special protein called the p53 and its vital role in cell cycle is stopped it allows the cell time to repair
the prevention of cancer development. the damage by regulating the expression of genes
essential for various DNA repair pathways, including
base excision repair and nucleotide excision repair.
To go over a brief explanation of how cancer occurs, If the damage is deemed irreparable, p53 can trigger
we also have to be familiar with the cell cycle. Cancer in apoptosis, or programmed cell death, to eliminate
cells often emerges as a result of DNA damage due to potentially cancerous cells, preventing damaged
various factors, including exposure to carcinogens (like cells from surviving, which is crucial for avoiding the
tobacco smoke or radiation), genetic predisposition, accumulation of mutations that could lead to cancer.
or random errors during cell division and this event Through these roles, p53 helps maintain genomic
causes many perturbations in its normal mechanisms. stability, making its proper functioning essential for the
Cancerous cells experience uncontrolled growth and health of the organism.
division, allowing them to continue proliferating even
when their DNA is damaged. They evade programmed
cell death (apoptosis) and promote angiogenesis, the Understanding the intricate relationship between
formation of new blood vessels, ensuring they receive cancer, the cell cycle, and the role of p53 highlights
the nutrients and oxygen necessary for their continued the delicate balance that cells must maintain for
growth. So in order to detect the DNA damage before healthy growth and division. The failure of this balance
it results in a cancerous cell, there are various control can lead to uncontrolled cell proliferation and the
stops during the cell cycle. These “control stops” development of cancer. Ongoing research into p53
are called checkpoints and there are a few major and its regulatory pathways offers hope for developing
checkpoints that we are going to focus on which are targeted therapies that can restore normal cell cycle
the G1/S and G2/M checkpoints in the cell cycle. The regulation and improve cancer treatment outcomes.
cell cycle is a series of phases that cells undergo to By unraveling the complexities of cancer biology, we
grow and divide. It consists of four main phases: G1 can move closer to effective prevention and treatment
(Gap 1), S (Synthesis), G2 (Gap 2), and M (Mitosis). strategies, ultimately enhancing our ability to combat
During the G1 phase, the cell grows and prepares for this devastating group of diseases.
DNA replication. The S phase is where DNA replication
occurs, followed by the G2 phase, where the cell
prepares for mitosis, ensuring that all DNA is correctly Damla Töre
replicated. Finally, during the M phase, the cell divides
into two daughter cells. During the checkpoints,

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