Drug That Treats Cocaine Addiction May Curb Colon Cancer

A drug first developed to treat cocaine addiction might also help slow the spread of advanced colon cancer, a new study suggests.

The drug vanoxerine appears to suppress cancer stem cell activity by essentially rewiring gene networks critical to tumor growth, the researchers explained.

“Tumors treated with vanoxerine become more susceptible to attack by the immune system due to the reactivation of ancient viral DNA fragments accumulated in our genome throughout evolution,” explained lead researcher Yannick Benoit, an associate professor of cellular and molecular medicine at the University of Ottowa in Canada.

“This finding is quite significant, considering that colorectal tumors tend to show poor response to standard immunotherapy,” Benoit added in a university news release.

Colon cancer is the world’s second-leading cause of cancer-related deaths, and it is considered a silent killer because it typically doesn’t show symptoms until the cancer is advanced.

Vanexorine interferes with a protein that transports dopamine, the brain chemical involved in sensations of pleasure and reward. Because of this, it was first developed to help people with an addiction to cocaine.

But the drug also suppresses a key enzyme in colon cancer cells, the researchers discovered.

Vanexorine suppressed stem cell activity in the tumors of colon cancer patients, as well as in tumors implanted into lab animals.

The drug also produced minimal toxic side effects in both humans and lab mice, Benoit said.

This indicates vanexorine could prove “a safe way to eliminate cancer stem cells in colorectal tumors without harming the ‘good stem cells’ in the body's organs,” Benoit added.

The findings were published Feb. 15 in the journal Nature Cancer.

Further research will be needed to fully test the ability of vanexorine to slow or stop colon cancer, the researchers added.

“For those unfortunate people diagnosed with advanced and aggressive forms of colorectal cancer, we profoundly hope our work can lead to the development of powerful options for treatment in the future and substantially increase their survival chances,” Benoit said.

https://en.wikipedia.org/wiki/Vanoxerine

Drug That Treats Cocaine Addiction May Curb Colon Cancer 

Methylphenidate facilitates recovery from drug addiction...

A brain-scanning study at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory, conducted with collaborators from Stony Brook University, reveals that an oral dose of methylphenidate, commonly known as Ritalin, improves impaired brain function and enhances cognitive performance in people who are addicted to cocaine.

Researchers were encouraged by the fact that, methylphenidate does decrease behaviors such as risk taking and impulsivity and improves brain function and cognitive performance in a range of other conditions that also affect the brain's prefrontal cortex, including attention deficit hyperactivity disorder (ADHD), some forms of dementia, and certain kinds of brain injury. To begin with Goldstein's (lead researcher)  group performed functional magnetic resonance imaging (fMRI) on 13 cocaine users and 14 healthy control subjects who were asked to perform a cognitive task after being given either a low oral dose of methylphenidate (20 milligrams) or a placebo. The task involved pushing a button to correctly identify the color of a printed word; some words had to do with drug use, others were "neutral." Subjects received monetary rewards for correct answers. The scientists were particularly interested in two parts of the prefrontal cortex previously shown to be impaired during this cognitive activity in cocaine-addicted individuals.

"These regions help to regulate emotion, cognition, and behavior in response to salient stimuli - the things we find particularly interesting or relevant," Goldstein said. "Because drug users have deficits in these regions, they may have less ability to regulate their emotions and exert cognitive control over certain behaviors."

Researchers found that,  compared  with cocaine users given placebos - who (compared to healthy controls) exhibited reduced function in these prefrontal cortex regions - cocaine users given a low dose of methylphenidate had improved brain function such that they were more like the healthy control subjects. The subjects given methylphenidate were also less likely to make "errors of commission" (pressing a button incorrectly or prematurely), a measure of impulsivity, while performing the cognitive task than subjects given a placebo. Furthermore, the greater the improvement in task accuracy with methylphenidate, the larger the increase in fMRI signal in the prefrontal cortex regions of interest, showing that the improvements in brain function were directly related to improved cognitive performance.

Though future studies need to evaluate whether these results can be generalized to other tasks or activities that involve these specific brain regions, but these results do suggest that by enhancing prefrontal cortex function and associated cognitive performance - particularly the decrease in impulsivity - methylphenidate could help to improve clinical outcomes in people seeking to overcome drug addiction…

  

 Ref : http://www.pnas.org/content/early/2010/08/30/1011455107.full.pdf+html?sid=be34425f-b8cc-4a90-8929-03aca9f8bbe4