Navigation Links
How vitamin C stops the big 'C'

Nearly 30 years after Nobel laureate Linus Pauling famously and controversially suggested that vitamin C supplements can prevent cancer, a team of Johns Hopkins scientists have shown that in mice at least, vitamin C - and potentially other antioxidants - can indeed inhibit the growth of some tumors just not in the manner suggested by years of investigation.

The conventional wisdom of how antioxidants such as vitamin C help prevent cancer growth is that they grab up volatile oxygen free radical molecules and prevent the damage they are known to do to our delicate DNA. The Hopkins study, led by Chi Dang, M.D., Ph.D., professor of medicine and oncology and Johns Hopkins Family Professor in Oncology Research, unexpectedly found that the antioxidants actual role may be to destabilize a tumors ability to grow under oxygen-starved conditions. Their work is detailed this week in Cancer Cell.

The potential anticancer benefits of antioxidants have been the driving force for many clinical and preclinical studies, says Dang. By uncovering the mechanism behind antioxidants, we are now better suited to maximize their therapeutic use.

Once again, this work demonstrates the irreplaceable value of letting researchers follow their scientific noses wherever it leads them, Dang adds.

The authors do caution that while vitamin C is still essential for good health, this study is preliminary and people should not rush out and buy bulk supplies of antioxidants as a means of cancer prevention.

The Johns Hopkins investigators discovered the surprise antioxidant mechanism while looking at mice implanted with either human lymphoma (a blood cancer) or human liver cancer cells. Both of these cancers produce high levels of free radicals that can be suppressed by feeding the mice supplements of antioxidants, either vitamin C or N-acetylcysteine (NAC).

However, when the Hopkins team examined cancer cells from cancer-implanted mice not fed the antioxidants, they noticed the absence of any significant DNA damage. Clearly, if DNA damage was not in play as a cause of the cancer, then whatever the antioxidants were doing to help was also not related to DNA damage, says Ping Gao, Ph.D, lead author of the paper.

That conclusion led Gao and Dang to suspect that some other mechanism was involved, such as a protein known to be dependent on free radicals called HIF-1 (hypoxia-induced factor), which was discovered over a decade ago by Hopkins researcher and co-author Gregg Semenza, M.D., Ph.D., director of the Program in Vascular Cell Engineering. Indeed, they found that while this protein was abundant in untreated cancer cells taken from the mice, it disappeared in vitamin C-treated cells taken from similar animals.

When a cell lacks oxygen, HIF-1 helps it compensate, explains Dang. HIF-1 helps an oxygen-starved cell convert sugar to energy without using oxygen and also initiates the construction of new blood vessels to bring in a fresh oxygen supply.

Some rapidly growing tumors consume enough energy to easily suck out the available oxygen in their vicinity, making HIF-1 absolutely critical for their continued survival. But HIF-1 can only operate if it has a supply of free radicals. Antioxidants remove these free radicals and stop HIF-1, and the tumor, in its tracks.

The authors confirmed the importance of this hypoxia protein by creating cancer cells with a genetic variant of HIF-1 that did not require free radicals to be stable. In these cells, antioxidants no longer had any cancer-fighting power.


Contact: Nick Zagorski
Johns Hopkins Medical Institutions

Related medicine news :

1. Vitamin B12 can help in detecting cancers
2. Vitamins-The answer to Heart Disease?
3. Vitamin E, the latest warrior against diabetes
4. Vitamin Shields Brittle Bones
5. Beer vitamin protects heart
6. B Vitamin protects and lowers toxicity of Arthritis Drug
7. B Vitamin Supplementatoin Saves Money and Lives
8. Eat Vitamin C and stay young
9. Vitamin C for the heart
10. Vitamin B for Hepatitis
11. Vitamins reduce pre-eclampsia
Post Your Comments:
(Date:6/26/2016)... Viejo, California (PRWEB) , ... June 26, 2016 , ... ... Final Cut Pro X. , "Film editors can give their videos a whole new ... said Christina Austin - CEO of Pixel Film Studios. , ProSlice Levels contains ...
(Date:6/25/2016)... ... June 25, 2016 , ... Experts ... applications at AcademyHealth’s Annual Research Meeting June 26-28, 2016, at the Hynes Convention ... health care topics including advance care planning, healthcare costs and patient and family ...
(Date:6/25/2016)... Lewisville, TX (PRWEB) , ... June 25, 2016 , ... ... in the United States, named Dr. Sesan Ogunleye, as the Medical Director of its ... be the facility Medical Director of our new Mesquite location,” said Dr. James M. ...
(Date:6/25/2016)... , ... June 25, 2016 , ... Conventional wisdom preaches ... success. In terms of the latter, setting the bar too high can result in ... than just slow progress toward their goal. , Research from ...
(Date:6/24/2016)... ... , ... Marcy was in a crisis. Her son James, eight, was out of control. Prone ... physically. , “When something upset him, he couldn’t control his emotions,” remembers Marcy. “If ... at my other children and say he was going to kill them. If we ...
Breaking Medicine News(10 mins):
(Date:6/23/2016)... HOUSTON , June 23, 2016  MedSource ... platform as its e-clinical software solution of choice.  ... the best possible value to their clients by ... nowEDC.  The preferred relationship establishes nowEDC as the ... pricing for MedSource,s full-service clients.  "nowEDC has long ...
(Date:6/23/2016)... 23, 2016 Any dentist who has made an ... current process. Many of them do not even offer this ... and high laboratory costs involved. And those who ARE able ... such a high cost that the majority of today,s patients ... Parsa Zadeh , founder of Dental Evolutions Inc. and ...
(Date:6/23/2016)... 2016  In a startling report released today, National Safety ... lacking a comprehensive, proven plan to eliminate prescription opioid overdoses. ... how states are tackling the worst drug crisis in recorded U.S. ... Kentucky , New Mexico , ... Of the 28 failing states, three – Michigan ...
Breaking Medicine Technology: