Since the time of the Ancient Egyptians, cancer has been a disease plaguing humankind. According to cancer.org the word cancer was created by Hippocrates, who was considered by many to be the father of medicine. While there was no cure for the disease then, science has developed new techniques, such as radiation, chemotherapy, and more recently immunotherapy. During the time of the Ancient Egyptians, there was no cure or treatment available because the understanding of cancer was limited (Early History of Cancer, 2014). Oncology, the study of cancer, only began in 1761 after Giovanni Morgagni conducted autopsies related to the illness. Around this time, the only treatment available was surgery to remove the tumor. If the tumor had already began to move, then the surgery was most likely not done (Cancer in the Sixteenth to Eighteenth Century, 2014).
Cancer is caused when cells grow and divide out of control. The acceleration of proliferation, or cells growing and dividing, causes DNA mutations to accumulate. The breakdown of the cell-cycle, the inhibition of proto-oncogenes such as p53, and the use of oncogenes drives the formation of cancer. Cancer cells skip checkpoint in the cell cycle, and thus divide with mutated DNA. Without the cell cycle regulation and without greater apoptosis around the body, these proliferating cells accumulate and become a tumor, which is called tumorigenesis (What is Cancer, 2015). In some cases, a cell can get into the bloodstream and travel to a different part of the body, a process called metastasis (What is Cancer, 2015). Cancers are named for their origin, however (What is Cancer, 2015). According to cancer.gov, 1,685,210 new cases of cancer will be diagnosed in a year. The most common will be breast cancer. According to breastcancer.org, 1 in 8 women in the US will develop invasive breast cancer over their lifetime.
Metabolism is the total chemical reactions in a cell. Cellular respiration is the use of food as an energy source and chemically altering it to a form of energy the body can use and one of the most important metabolic pathways. In oxidative respiration, there are four stages. Glycolysis is the transformation of sugar, or in some cases fat and proteins, into pyruvate molecules, 2 NADH (an electron carrier) and 2 ATP. This occurs through series of chemical reactions within the cell. The next stage is called the link reaction, wherein the pyruvate molecules form into Acetyl-CoA for the third step: Krebs Cycle. During the Krebs cycle, the Acetyl-CoA undergoes many reactions and produces 2 ATP as well as NADH and FADH2 (electron carriers). Finally, the fourth step: oxidative phosphorylation. The electron acceptors power the membrane proteins on the inner mitochondrial membrane. All the H+ ions actively transport from the mitochondrial matrix to the intermembrane space. The electrons are the energy source and thus NADH is converted to NAD+ and H+, FADH2 is converted to FAD+ and 2H+, and the remaining electrons are picked up by oxygen to create water. Then, the H+ ions diffuse from the intermembrane space to the mitochondrial matrix through a channel called ATP Synthase,which powers the ATP synthase to create ATP from ADP and a phosphate (Cellular Respiration, 2004).
This can only occur when oxygen is present. So what happens when there is not enough oxygen? The cell uses anaerobic respiration. The cell will only use glycolysis to create its energy. Under anaerobic conditions, metabolism in the cell results in lactic acid formation that leads to muscle cramps (Cellular Respiration, 2004). Hypoxia is a condition of low oxygen availability. Many cancer cells are under hypoxic conditions, so they use anabolic metabolism to meet their needs (Semenza, 2016) (Ward and Thompson, 2012). Anabolic metabolism is the synthesis of molecules from smaller molecules. This is beneficial to cancer cells because it allows them to meet the demands of proliferating cells. Metabolism results in increased production of certain enzymes or proteins (Ward and Thompson, 2012). The production of lipids,specifically phospholipids, is controlled by choline metabolism, that frequently undergoes metabolic reprogramming resulting in an increase in lipid production. Choline metabolism is critical for cancer cells because the formation of phospholipids can go towards a new cell membrane for a daughter cell (Glunde et al, 2011).
Cancer is caused when cells grow and divide out of control. The acceleration of proliferation, or cells growing and dividing, causes DNA mutations to accumulate. The breakdown of the cell-cycle, the inhibition of proto-oncogenes such as p53, and the use of oncogenes drives the formation of cancer. Cancer cells skip checkpoint in the cell cycle, and thus divide with mutated DNA. Without the cell cycle regulation and without greater apoptosis around the body, these proliferating cells accumulate and become a tumor, which is called tumorigenesis (What is Cancer, 2015). In some cases, a cell can get into the bloodstream and travel to a different part of the body, a process called metastasis (What is Cancer, 2015). Cancers are named for their origin, however (What is Cancer, 2015). According to cancer.gov, 1,685,210 new cases of cancer will be diagnosed in a year. The most common will be breast cancer. According to breastcancer.org, 1 in 8 women in the US will develop invasive breast cancer over their lifetime.
Metabolism is the total chemical reactions in a cell. Cellular respiration is the use of food as an energy source and chemically altering it to a form of energy the body can use and one of the most important metabolic pathways. In oxidative respiration, there are four stages. Glycolysis is the transformation of sugar, or in some cases fat and proteins, into pyruvate molecules, 2 NADH (an electron carrier) and 2 ATP. This occurs through series of chemical reactions within the cell. The next stage is called the link reaction, wherein the pyruvate molecules form into Acetyl-CoA for the third step: Krebs Cycle. During the Krebs cycle, the Acetyl-CoA undergoes many reactions and produces 2 ATP as well as NADH and FADH2 (electron carriers). Finally, the fourth step: oxidative phosphorylation. The electron acceptors power the membrane proteins on the inner mitochondrial membrane. All the H+ ions actively transport from the mitochondrial matrix to the intermembrane space. The electrons are the energy source and thus NADH is converted to NAD+ and H+, FADH2 is converted to FAD+ and 2H+, and the remaining electrons are picked up by oxygen to create water. Then, the H+ ions diffuse from the intermembrane space to the mitochondrial matrix through a channel called ATP Synthase,which powers the ATP synthase to create ATP from ADP and a phosphate (Cellular Respiration, 2004).
This can only occur when oxygen is present. So what happens when there is not enough oxygen? The cell uses anaerobic respiration. The cell will only use glycolysis to create its energy. Under anaerobic conditions, metabolism in the cell results in lactic acid formation that leads to muscle cramps (Cellular Respiration, 2004). Hypoxia is a condition of low oxygen availability. Many cancer cells are under hypoxic conditions, so they use anabolic metabolism to meet their needs (Semenza, 2016) (Ward and Thompson, 2012). Anabolic metabolism is the synthesis of molecules from smaller molecules. This is beneficial to cancer cells because it allows them to meet the demands of proliferating cells. Metabolism results in increased production of certain enzymes or proteins (Ward and Thompson, 2012). The production of lipids,specifically phospholipids, is controlled by choline metabolism, that frequently undergoes metabolic reprogramming resulting in an increase in lipid production. Choline metabolism is critical for cancer cells because the formation of phospholipids can go towards a new cell membrane for a daughter cell (Glunde et al, 2011).