Vitamin D, Calcium can Boost Colon Cancer Cell Death

[Guest guest]

Emory University

Vitamin D and calcium influence cell death in the colon, researchers

find

Researchers at Emory University are learning how vitamins and

minerals in the diet can stimulate or prevent the appearance of

colon cancer.

Emory investigators will present their findings on biological

markers that could influence colon cancer risk in three abstracts at

the American Association for Cancer Research meeting in San Diego.

In a clinical study of 92 patients, supplementing diet with calcium

and vitamin D appeared to increase the levels of a protein called

Bax that controls programmed cell death in the colon. More Bax might

be pushing pre-cancerous cells into programmed cell death, says

Emory researcher Veronika Fedirko, who will present her team's

results (abstract 464).

Previous studies have shown that calcium and vitamin D tend to

reduce colon cancer risk.

" We were pleased that the effects of calcium and vitamin D were

visible enough in this small study to be significant and

reportable, " Fedirko says. " We will have to fully evaluate each

marker's strength as we accumulate more data. "

The studies of colorectal biopsy samples are part of a larger effort

to identify a portfolio of measurements that together can gauge

someone's risk of getting colon cancer, says Roberd Bostick, MD,

MPH, professor of epidemiology at Emory's Rollins School of Public

Health.

" We want to have the equivalent of measuring cholesterol or high

blood pressure, but for colon cancer instead of heart disease, "

Bostick says. " These measurements will describe the climate of risk

in the colon rather than spotting individual tumors or cells that

may become tumors. "

More about Bostick's plans for developing non-invasive blood or

urine tests for colon cancer risk is available in an Emory Health

Sciences Magazine article:

http://whsc.emory.edu/_pubs/hsc/winter08/pdf/hold_out_your_finger.pdf

Another abstract from Bostick and his colleagues (565) demonstrates

in a 200-patient case-control study that high levels of calcium and

vitamin D together are associated with increased levels of E-

cadherin, which moderates colon cells' movement and proliferation.

A third abstract on the same case-control study (5504) shows that

high levels of iron in the diet are linked to low levels of APC, a

protein whose absence in colon cancer cells leads to their runaway

growth.

Bostick and his colleagues are participating in a ten-year multi-

center study of the effects of increased vitamin D and calcium and

biomarker-guided treatment of colon cancer recurrence. The study

involves almost 2,500 people nationwide who have regular

colonoscopies.