Unrestrained growth is one of the signatures of cancer cells. Consequently, to slow or halt the progression of the disease, it is important to first determine what causes this kind of tumor growth.
Researchers at the University of Pennsylvania hoped to make progress in understanding the growth of cancerous tumors by studying mitochondria. The team found that when key components of the mitochondria were disrupted by silencing specific proteins in the organelle, normal cells began to show characteristics of the cells found in cancerous tumors.
"That result alone couldn't tell us whether that was the cause or effect of tumors, but our cell system clearly says that mitochondrial dysfunction is a driving force in tumorigenesis," Narayan Avadhani, Ph.D., a professor of biochemistry in UPenn's School of Veterinary Medicine, said in a statement. The study was led by members of Avadhani's lab.
Exploring the powerhouse
The mitochondria is often referred to as the "powerhouse" of the cell because it produces most of the cell's adenosine triphosphate, more commonly known as ATP, which is used as energy. The researchers were interested in examining the organelle to determine if defects would contribute to the growth of cancerous tumors.
"The first part of the Warburg hypothesis has held up solidly in that most proliferating tumors show high dependence on glucose as an energy source and they release large amounts of lactic acid," Avadhani said in a press release. "But the second part, about the defective mitochondrial function causing cells to be tumorigenic, has been highly contentious."The study was built on observations made by German biologist Otto Heinrich Warburg. According to the official website of the Nobel Prize, Warburg's studies included the respiration of cells and tumor metabolism, and he was particularly interested in cancer cells. In 1924, Warburg observed that glucose was consumed at a higher rate in cancerous cells than in normal cells and that those malignant cells additionally had defects in the mitochondria.
Testing the theory
The team tested the second part of Warburg's postulation by taking cells and silencing the expression of particular parts of the mitochondria's cytochrome oxidase C or CcO using RNA molecules.
"Disruptions created cells that showed all the signs of cancer."
According to the report, the scientists observed major changes in the mitochondria and cells after disrupting only a single protein subunit of CcO. Avadhani reported that the resulting cells showed all the signs of a cancer cell.
The researchers similarly silenced the subunits in lines that were already cancerous and found that it made the cells more invasive, increasing their malignant potency. They further found that when human tumors were examined, the most oxygen-starved areas contained versions of CcO that were defective.
The findings suggest that these defects in cytochrome oxidase C could be potential biomarkers during cancer screening.
The research was published in the journal "Oncogene."
Researchers inch closer to learning why migraines occur
There's nothing subtle about a migraine. Yet the cause of one type has baffled medical experts for years – perhaps until now.
Dr. Barbara Lee Peterlin, D.O., and her team of researchers from John Hopkins University School of Medicine in Baltimore, may have discovered a biomarker for episodic migraines.
America's headache
Chronic Migraines plague more than 3.2 million Americans, according to MyChronicMigraine.com. Only about 20 percent of cases are diagnosed, which means most people experience these painful episodes and either can't or aren't getting health care experts' input.
"Chronic Migraines plague more than 3.2 million Americans."
Different from the occasional migraine, episodic migraines occur more frequently. MyChronicMigraine.com explained that people who get them experience 15 headaches per month on average. They can strike at anytime and a number of environmental factors can trigger them, including an abrupt change in climate, an alteration in meal times, a difference in sleep patterns and excess stress.
A treatment has yet to be found, which is why the findings from the John Hopkins' study are exciting, explained Peterlin.
"While more research is needed to confirm these initial findings, the possibility of discovering a new biomarker for migraine is exciting," said Peterlin.
Blood tests might help
Researchers arrived at this conclusion, which was published in the journal Neurology, by conducting neurological exams on 52 women who were diagnosed with episodic migraines. Additionally, researchers examined 36 women who were not diagnosed with the condition.
Study authors checked each participants body mass index and took blood samples to measure the level of ceramades in the bloodstream, which controls inflammation in the brain. As it turns out, women whose ceramide levels decreased were more at risk of developing a migraine than those who had higher levels.
More specifically, participants with episodic migraines had about 6,000 nanograms of ceramides in their blood. Those who experienced the painful headaches had about 10,500 nanograms.
While scientists believe that this experiment should be duplicated to strengthen its results, potentially finding a biomarker for episodic migraines is certainly a beacon of hope for many Americans.
"This study is a very important contribution to our understanding of the underpinnings of migraine and may have wide-ranging effects in diagnosing and treating migraine if the results are replicated in further studies," explained Dr. Karl Ekbom, of the Karolinska Institutet in Stockholm, Sweden.