Navigation Links
How vitamin C stops the big 'C'
Date:9/10/2007

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
nzagors1@jhmi.edu
443-287-2251
Johns Hopkins Medical Institutions
Source:Eurekalert

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:
*Name:
*Comment:
*Email:
(Date:8/18/2017)... ... 18, 2017 , ... MLM Insurance Group, a Miami area ... Florida, is working to support the Take Stock In Children Foundation during a ... , The Take Stock In Children Foundation (TSC) offers guidance and assistance to ...
(Date:8/18/2017)... Humble, TX (PRWEB) , ... August 18, 2017 ... ... insurance management and financial planning firm that serves residential and commercial clients in ... a charity drive to raise community support for the fight against cancer. , ...
(Date:8/18/2017)... St. Louis, Missouri (PRWEB) , ... August 18, 2017 , ... ... ” says Suzanne Tucker, Founder of St. Louis-based positive education company Generation Mindful. To ... way they help children learn social and emotional skills, she created the Time-In Toolkit, ...
(Date:8/18/2017)... ... August 18, 2017 , ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh in ... veil on false teachings pertaining to the mother of the Savior whom the world calls ... far different picture of the role of this historical woman. , “The world bows, ...
(Date:8/18/2017)... SAN DIEGO, CA & CARMEL, IN (PRWEB) , ... August 18, ... ... No. 3828 on its 36th annual list, the most prestigious ranking of the nation's ... ASH has been included in the exclusive Inc. 5000 ranking . This year’s ...
Breaking Medicine News(10 mins):
(Date:8/7/2017)... 2017 Insightin Health, provider of data-driven ... engagement, announced the selection of Michael Wood ... effective as of February 2017. In this role, Wood ... for our clients. Wood brings with him more ... business analytics within the healthcare industry. Wood formerly ...
(Date:8/7/2017)... -- Diplomat Pharmacy, Inc. (NYSE: DPLO ) today ... effective Aug. 7, 2017. ... interests and will serve as president emeritus during a planned, ... in multiple leadership roles since he joined Diplomat with the ... provided decisive, strategic leadership which continues to benefit our patients ...
(Date:8/7/2017)... , Aug. 7, 2017  Endo International plc (NASDAQ: ... agreements to resolve virtually all known U.S. mesh product ... to resolve the known remaining U.S. claims at reasonable ... beginning in the fourth quarter of 2017 and continuing ... its second quarter 2017 results, the Company intends to ...
Breaking Medicine Technology: