Meth Use Causes Cancer-like Biological Damage
Researchers at the University of Illinois at Urbana-Champaign (UIUC) have discovered that meth use can severely impact not only brain activity, but also whole-body cellular function on multiple levels. Their new study is the first to look at cellular damage caused by the toxicity of methamphetamine throughout the entire body.
Prior to their study, methamphetamine’s toxicity on the brain has been well documented, yet its effects on the molecular level had not yet been well understood. In their recent investigation, Barry Pittendrigh, professor of entomology at UIUC, and a large team of researchers sought to identify the numerous damages caused to the body’s protein, cellular, and metabolic functions by meth exposure. For their study, the researchers studied the changes caused to genes and proteins in fruit flies exposed to methamphetamine. Because they are such small animals, fruit flies give scientists the opportunity to explore the entire organism and its several systems and tissues as they are altered by drug exposure. Using fruit flies, in fact, helped the researchers identify the numerous molecular pathways that are significantly impacted by meth exposure, pathways that are also common among humans and other species. Because of the drug’s multifaceted and devastating effects on a biological level—including cellular, cardiac, and hormonal dysfunction—the researchers describe exposure to methamphetamine as a ‘perfect storm toxin.’ Their study was recently published online in the journal PLoS ONE.
According to Pittendrigh and colleagues, methamphetamine causes such potent and sometimes destructive damage to several biological functions—including energy generation; sugar, protein, iron, and calcium metabolism; sperm production; hormones; physiology of skeletal and cardiac muscle; processes related to aging; and cell structure—that it seemingly mimics the effects of cancerous growth. In normal, healthy cell production, cells rely on oxygen to metabolize energy in a slow and efficient process known as oxidative respiration. When this process is disrupted by meth exposure, the researchers noticed that the cells’ energy metabolism was significantly affected in the same manner as rapid cancerous growth. Unlike normal cellular processes, cancerous cells thrive off the rapid breakdown of glucose, a process called glycolysis that does not depend on oxygen even when oxygen is present. This dysfunctional process to energy metabolism seen in cancerous cells is known as the Warburg effect (aerobic glycolysis). Among their fruit fly specimens, the researchers observed that acute meth exposure caused significant changes to energy metabolism that mirrored the Warburg effect.
Because of this discovery, the researchers hypothesized that the metabolism of carbohydrates is essential to methamphetamine’s toxicity. In healthy glycolysis, normal cells use glucose—an important carbohydrate—to produce energy; yet when methamphetamine or cancerous cells are present, the metabolism of sugar creates a ‘toxic syndrome’ in the body. During the study, if the fruit flies were given dietary sugars called trehalose, the toxic effects of methamphetamine were partially alleviated and the flies lived longer. The researchers suggest that this finding helps explain why methamphetamine users often crave sugary substances, as increased sugar intake was seen to alleviate the toxicity of meth.
In addition to these dysfunctions to carbohydrate metabolism and energy-production processes, the researchers found that methamphetamine caused disruption to the critical growth of calcium and iron in cells. Their study identified a number of genes that are possibly involved in the meth-induced disruption of such cellular events as sperm growth. Although the fruit fly model gave the researchers a model platform from which to observe methamphetamine’s effects on a molecular level, the researchers acknowledge that further investigation will be needed to confirm the same molecular pathways affected by meth in humans. Nonetheless, the researchers state that identifying the molecular processes which occur to fruit flies exposed to methamphetamine, such as the Warburg effect and cell death, can also help scientists better understand the development of malignant cell growth in future studies.
Source: MedNews Today, Study Explores Whole-Body Effects Of Meth In Fruit Flies, April 21, 2011
